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Title: Pumps and Hydraulics - Part Two
Author: Rogers, Will
Language: English
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Transcriber’s notes:
The spelling, punctuation and hyphenation are as the original except
for apparent typographical errors, which have been corrected.
Italic text is denoted _thus_.
Bold text is denoted =thus=.
Bold, sans serif text, representing physical appearance e.g., of a
‘Tee’ shaped wrench is denoted thus ^T^.
Both ‘gauge’ and ‘gage’ appear in the text and have not been changed.
FIG. 454. is used twice in the original book, the 2nd occurrence has
been renamed FIG. 454A.
FIG. 551 was omitted from the original sequence of illustrations.
Units of pressure, e.g., ‘pounds’ and ‘lbs.’ should be ‘pounds per
square inch’ and ‘lbs. per square inch’ respectively, for completeness.
This is left as printed in the original book.
PUMPS
AND
HYDRAULICS.
IN TWO PARTS.
Part Two.
[Illustration: TEN THOUSAND HORSE POWER.
(See Part One, Page 133.)]
PUMPS
AND
HYDRAULICS
BY
WILLIAM ROGERS
_Author of “Drawing and Design,” etc._
[Illustration]
_RELATING TO_
HAND PUMPS; POWER PUMPS; PARTS OF PUMPS; ELECTRICALLY DRIVEN PUMPS;
STEAM PUMPS, SINGLE, DUPLEX AND COMPOUND; PUMPING ENGINES, HIGH DUTY
AND TRIPLE EXPANSION; THE STEAM FIRE ENGINE; UNDERWRITERS’ PUMPS;
MINING PUMPS; AIR AND VACUUM PUMPS; COMPRESSORS; CENTRIFUGAL AND
ROTARY PUMPS; THE PULSOMETER; JET PUMPS AND THE INJECTOR; UTILITIES
AND ACCESSORIES; VALVE SETTING; MANAGEMENT; CALCULATIONS, RULES AND
TABLES.
_WITH ILLUSTRATIONS._
_ALSO_
GENERAL CONSIDERATIONS; GLOSSARY OF PUMP TERMS; HISTORICAL
INTRODUCTION, WITH ILLUSTRATIONS; THE ELEMENTS OF HYDRO-MECHANICS,
HYDROSTATICS AND PNEUMATICS; GRAVITY AND FRICTION; HYDRAULIC
MEMORANDA; LAWS GOVERNING FLUIDS; WATER PRESSURE MACHINES; PUMPS AS
HYDRAULIC MACHINES, ETC.
PART TWO.
PUBLISHED BY
THEO. AUDEL & COMPANY
72 FIFTH AVE.,
NEW YORK, U.S.A.
7, IMPERIAL ARCADE,
LUDGATE CIRCUS, E.C.,
LONDON, ENG.
Copyrighted, 1905, by
THEO. AUDEL & CO., NEW YORK.
Entered at Stationers Hall, London, England.
Protected by International Copyright in Great Britain and all
her Colonies, and, under the provisions of the
Berne Convention, in
Belgium, France, Germany, Italy, Spain, Switzerland, Tunis,
Hayti, Luxembourg, Monaco, Montinegro
and Norway.
Printed in the United States.
TABLE OF CONTENTS
_Part TWO._
The divisions of Part Two are represented by the following headings:
each subject is fully treated and illustrated on the pages shown:
pages
INTRODUCTION TO PART TWO 1-10
THE AIR PUMP 13-30
AIR AND VACUUM PUMPS 31-56
AIR COMPRESSORS 57-78
THE AIR LIFT PUMP 79-90
THE STEAM FIRE ENGINE 91-142
MISCELLANEOUS PUMPS 143-176
MINING PUMPS 145-155
MARINE PUMPS 155-162
“SUGAR-HOUSE” PUMPS 165-167
CIRCULATING PUMPS 168
ATMOSPHERIC PUMPS 169-170
AMMONIA OR ACID PUMPS 171
THE SCREW PUMP 175-176
AERMOTOR PUMPS 177-192
ROTARY AND CENTRIFUGAL PUMPS 193-229
TURBINE PUMPS 231-242
INJECTORS AND EJECTORS 243-266
PULSOMETER AQUA-THRUSTER 267-280
PUMP SPEED GOVERNORS 281-296
CONDENSING APPARATUS 297-314
UTILITIES AND ATTACHMENTS 315-334
TOOLS, VALVES AND PIPING 335-356
PIPES, JOINTS AND FITTINGS 357-368
USEFUL NOTES 369-386
TABLES AND DATA 387-400
READY REFERENCE INDEX TO PART TWO
PREFACE.
The owner of a great tannery had once an improvement in making leather
proposed to him by a foreman, but the merchant could not comprehend
it even with the most earnest verbal explanation. As a last resort he
said, “put it in writing so that I can study it out.” This was done and
the change after an examination of the paper was made as advised. So in
these volumes much important information is written and printed that it
may be “studied out.”
The author believes the following features of his work adapt it to the
purpose for which it was designed:
1. It contains no more than can be mastered by the average engineer
and those associated with him, such as millwrights, machinists,
superintendents of motor power, electric stations, water works, etc.
2. It is thoroughly systematized. The order and development of subjects
is thought to be logical, and the arrangement of topics especially
adapted to the needs of those who aspire to do the best service in
their every day responsibilities.
3. The work is written in accordance with modern theories and practice;
no exertion has been spared in the attempt to make it fairly represent
the latest state of the science of hydraulics and its adaptation to
the needs of modern mechanical advancement, _i.e._, in the line of
practical hydraulics.
NOTE.—The preface is almost invariably made after the book itself
is finished, for an author never knows with much exactness whither
his researches will lead him. The book he begins is not always the
book he finished; this is especially the case with books relating
to modern sciences and industry. As an instance of this, it may be
told that at the commencement of this work it was generally agreed
that the easy “lift” of the centrifugal pump was some sixty or eighty
feet, and not much more, but the appropriate section relating to
centrifugal pumps has reached a lift of two thousand feet had been
practically assured by recent discoveries. This important difference
demanded a change in the writing although—as it happened—not in the
printing. This, to explain why here, the author gives generous praise
to others who have assisted in the long task of making these volumes.
4. It has been made by “men who know for men who care,” for the whole
circle of the sciences consists of principles deduced from the
discoveries of different individuals, in different ages, thrown into
common stock; this is especially so of the science of hydraulics; thus
it may be truthfully owned that the work contains the gathered wisdom
of the ages, utilized wherever the author has found that it would
increase the usefulness of the volumes.
5. It is a work of reference minutely indexed. We are warned by Prof.
Karl Pearson that “education can only develope; it cannot create. If
a man has not inherited ability to learn, education cannot make him
learn,” but in a well indexed book, simply and plainly written, both
classes referred to are equally benefited.
There came the moment, once upon a time, when the author of this book,
in his eager pursuit of knowledge, asked one question too much, to
which he received the “gruff” answer:
“Look ahere, I don’t propose to make a dictionary of myself.”
This was a painful retort from a man already under large obligations to
the questioner, but it had its reason in being spoken. There are things
in the way of a man’s own craft that he most unwillingly imparts to
anyone else.
It is not thus with this work; nothing has been withheld that would
make it plain and helpful to one in need of the special line of
information aimed to be conveyed in its make-up.
In making acknowledgment for favors received the author first remembers
Mr. Alberto H. Caffee who arranged in behalf of the L. Middleditch
Press for the issue of the work. Mr. Caffee’s name appears in the
dedication, with that of the brave soldier and accomplished gentleman
Maj. Abram B. Garner.
The latter is one to whom “Jove has assigned a wise, extensive, all
considerate mind.” The author is proud to call him friend and to
acknowledge the benefit received in kindly advice relating to his
productions.
Mr. Harry Harrison’s skill is shown in the “lay out” or typographical
arrangement of the work and Mr. Henry J. Harms has contributed his
careful supervision to each page of the book as it has gone through the
press.
Lewis F. Lyne, Mechanical Engineer, has, amid his other responsible and
active duties “passed upon” each page of the entire two volumes.
Mr. Lyne, it may be said, was one of the founders of the American
Society of M. E.; he was also the first mechanical engineer on the
editorial staff of the American Machinist in its early days, and
contributed as editor and stockholder to its success. In his youth
Mr. Lyne was apprentice in the machine shop of the Penn. R. R. and
received his papers for full and faithful service.
Having been commodore of the Pavonia Yacht Club he has papers both
as U. S. pilot and also as a marine engineer. He performed practical
service both as locomotive fireman and was later superintendent of
the Jersey City Electric Light Co. for a period of six and a half
years.
Moreover Mr. Lyne was assistant master mechanic of the Delaware,
Lackawanna & Western R. R. (M. & E. Div.) for seven years and had
charge of establishing their new shops at Kingsland, N. J. Few men
have had so long and honorable a record as Lewis Frederick Lyne.
Credit is due also to Mr. Edward F. Stevens, assistant at the Yale
University library, New Haven, Conn., for a careful reading of the
two volumes for clerical errors, punctuation, etc. Mr. Stevens is a
graduate of Colby University and a ripe scholar; moreover after leaving
college he has had some twelve or more years experience in business and
editing with a mechanical book publishing house widely known throughout
England and the U. S.—a rare combination of useful experience.
The final revision of the two volumes has been made by one of the
brightest young engineers in New York City, now consulting engineer and
attorney at Patent Law with offices in the Flat Iron Building, corner
of Twenty-third St. and Fifth Avenue—Mr. Edward Van Winkle.
He is associate member of the Am. Soc. M. E. and associate member of
the Canadian Soc. of C. E. He was a Student in The Stevens Institute
of Technology, and graduated from Columbia University in the City of
New York with the degree E. E.
These names should assure confidence in the contents of the work, which
has been some years in preparation, and with nothing spared to make it
trustworthy.
[Illustration]
_“Kicking down” a well in the early days._ A hole was dug in the rock
and cased with a wooden tube eight or ten inches square. In this way
the tools, suspended from a horizontal elastic hickory pole, which in
turn was fastened to a stake, were worked over an upright piece as a
fulcrum. The tools were worked up and down in the hole, as shown in the
picture.
THE AIR PUMP
“_There is this remarkable difference between bodies in a fluid and
bodies in a solid form, namely, that every particle of a fluid is
perfectly independent of every other particle. They do not cohere in
masses, like the particles of a solid, nor do they repel one another,
as is the case with the particles composing a gas. They can mingle
among each other with the least degree of friction, and, when they
press down upon one another by virtue of their own weight, the downward
pressure is communicated in all directions, causing a pressure upwards,
sideways, and in every possible manner. Herein the particles of a fluid
differ from the particles of a solid, even when reduced to the most
impalpable powder; and it is this which constitutes fluidity, namely,
the power of transmitting pressure in every direction, and that, too,
with the least degree of friction. The particles which compose a fluid
must be very much smaller than the finest grain of an impalpable
powder._”—RICHARD GREEN PARKER, A. M.
PNEUMATICS.
_Pneumatics treats of the mechanical properties and effects of air and
similar fluids_; these are called elastic fluids and gases, or aëriform
fluids.
_Hydro-pneumatics._ This is a compound word formed from two Greek words
signifying water and air; in its primary meaning it conveys the idea of
_the combined action of water and air or gas_.
[Illustration: FIG. 330.]
NOTE.—Fig. 330 is one of the simplest forms of an air pump. The
description accompanying Fig. 341 properly applies to this one.
_Air is the respirable fluid which surrounds the earth and forms its
atmosphere._ It is inodorous, invisible, insipid, colorless, elastic,
possessed of gravity, easily moved, rarefied and condensed, essential
to respiration and combustion, and is the medium of sound. It is
composed by volume of 20.7 parts of oxygen and 79.3 of nitrogen,
by weight, of 23 of oxygen and 77 of nitrogen. These gases are not
chemically united, but are mixed mechanically. Air contains also 1/2000
of carbon dioxide, some aqueous vapor, about one per cent. of argon,
and small varying amounts of ammonia, nitric acid, ozone, and organic
matter. The specific gravity of the air at 32° F is to that of water as
1 to 773, and 100 cubic inches of air at mean temperature and pressure
weighs 30-1/2 grains.
_Aëriform fluids are those which have the form of air._ Many of them
are invisible, or nearly so, and all of them perform very important
operations in the material world. But, notwithstanding that they
are in most instances imperceptible to our sight, _they are really
material, and possess all the essential properties of matter_. They
possess, also, in an eminent degree, all the properties which have
been ascribed to liquids in general, besides others by which they are
distinguished from liquids.
_Elastic fluids are divided into two classes, namely, 1, permanent
gases and, 2, vapors._ The gases cannot be easily converted into
the liquid state by any known process of art;* but the vapors are
readily reduced to the liquid form either by pressure or diminution of
temperature. There is, however, no essential difference between the
mechanical properties of both classes of fluids.
As the air which we breathe, and which surrounds us, is the most
familiar of all this class of bodies, it is generally selected as the
subject of Pneumatics. But it must be premised that the same laws,
properties and effects, which belong to air, belong in common, also, to
all aëriform fluids or gaseous bodies.
_There are two principal properties of air, namely, gravity and
elasticity._ These are called the principal properties of this class
of bodies, because they are the means by which their presence and
mechanical agency are especially exhibited.
Although the aëriform fluids all have weight, they appear to possess
_no cohesive attraction_.
The pressure of the atmosphere caused by its weight is exerted on
all substances, internally and externally, and it is a necessary
consequence of its fluidity. When the external pressure is artificially
removed from any part, it is immediately felt by the reaction of the
internal air.
Heat insinuates itself between the particles of bodies and forces them
asunder, in opposition to the attraction of cohesion and of gravity. It
therefore exerts its power against both the attraction of gravitation
and the attraction of cohesion. But, as the attraction of cohesion
does not exist in aëriform fluids, _the expansive power of heat upon
them has nothing to contend with but gravity_. Hence, any increase of
temperature, expands an elastic fluid prodigiously, and a diminution of
heat condenses it.
*NOTE.—Carbonic acid gas forms an exception to this assertion. Water
also is the union of oxygen and hydrogen gas.
A column of air, having a base an inch square, and reaching to the top
of the atmosphere, weighs about fifteen pounds. _This pressure, like
the pressure of liquids, is exerted equally in all directions._
_The elasticity of air_ and other aëriform fluids is that property by
which they are increased or diminished in extension, according as they
are compressed. This property exists in a much greater degree in air
and other similar fluids than in any other substance. In fact, it has
no known limit, for, when the pressure is removed from any portion of
air, it immediately expands to such a degree that the smallest quantity
will diffuse itself over an indefinitely large space. And, on the
contrary, when the pressure is increased, it will be compressed into
indefinitely small dimensions.
The elasticity or pressure of air and all gases is in direct
_proportion to their density_; or, what is the same thing, inversely
proportional to the space which the fluid occupies. This law, which
was discovered by Mariotte, is called “Mariotte’s Law.” This law may
perhaps be better expressed in the following language; namely, the
density of an elastic fluid is in direct proportion to the pressure
which it sustains.
_Air becomes a mechanical agent by means of its weight, its elasticity,
its inertia and its fluidity._
The fluidity of air invests it, as it invests all other liquids, with
the power of transmitting pressure; fluidity is a necessary consequence
of the independent gravitation of the particles of a fluid. It may,
therefore, be included among the effects of weight.
The inertia of air is exhibited in the resistance which it opposes to
motion, which has already been noticed under the head of Mechanics.
This is clearly seen in its effects upon falling bodies, as will be
exemplified in the experiments with the air-pump.
_The great degree of elasticity_ possessed by all aëriform fluids,
renders them susceptible of compression and expansion to an almost
unlimited extent. The repulsion of their particles causes them to
expand, while within certain limits they are easily compressed. This
materially affects the state of density and rarety under which they are
at times exhibited.
It may here be stated that all the laws and properties of liquids
(described under the heads of Hydrostatics and Hydraulics) belong also
to aëriform fluids.
The chemical properties of both liquids and fluids belong peculiarly
to the science of Chemistry, and are, therefore, not to any extent,
considered in this volume.
The air which we breathe is an elastic fluid, surrounding the earth,
and extending to an indefinite distance above its surface, and
constantly decreasing upwards in density. It has already been stated
that the air near the surface of the earth bears the weight of that
which is above it.
Being compressed, therefore, by the weight of that above it, it must
exist in a condensed form near the surface of the earth, while in the
upper regions of the atmosphere, where there is no pressure, it is
highly rarefied. This condensation, or pressure, is very similar to
that of water at great depths in the sea.
Besides the two principal properties, gravity and elasticity, the
operations of which produce most of the phenomena of Pneumatics,
it will be recollected that as air, although an invisible is yet a
material substance, possessing all the common properties of matter, it
possesses also the common property of _impenetrability_.
_The Thermometer is an instrument to indicate the temperature of the
atmosphere._ It is constructed on the principle that heat expands and
cold contracts most substances. The thermometer consists of a capillary
tube, closed at the top and terminating downwards in a bulb. It is
filled with mercury which expands and fills the whole length of the
tube or contracts altogether into the bulb, according to the degree of
heat or cold to which it is exposed. Any other fluid which is expanded
by heat and contracted by cold, may be used instead of mercury.
NOTE.—The terms “rarefaction” and “condensation,” and “rarefied” and
“condensed,” must be clearly understood in this connection. They are
applied respectively to the expansion and compression of a body.
As it has been proved by experiment that 100 cubic inches of air weighs
30-1/2 grains, it will readily be conceived that _the whole atmosphere
exercises a considerable pressure on the surface of the earth_. The
existence of this pressure is shown by the following experiments. On
one end of a stout glass cylinder, about 10 inches high, and open at
both ends, a piece of bladder is tied quite air-tight. The other end,
the edge of which is ground and well-greased, is pressed on the plate
of the air-pump, Fig. 331. As soon as the air in the vessel is rarefied
by working the air-pump, the bladder is depressed by the weight of the
atmosphere above it, and finally bursts with a loud report caused by
the sudden entrance of air.
[Illustration: FIG. 331.]
[Illustration: FIG. 332.]
[Illustration: FIG. 333.]
The preceding experiment only serves to illustrate the downward
pressure of the atmosphere. By means of the _Magdeburg hemispheres_,
Figs. 332 and 333, the invention of which is due to Otto von Guericke,
burgomaster of Magdeburg, it can be shown that the pressure acts in all
directions. This apparatus consists of two hollow brass hemispheres
of 4 to 4-1/2 inches diameter, the edges of which are made to fit
tightly, and are well greased. One of the hemispheres is provided with
a stop-cock, by which it can be screwed on to the air-pump, and on the
other there is a handle. As long as the hemispheres contain air they
can be separated without any difficulty, for the external pressure of
the atmosphere is counterbalanced by the elastic force of the air in
the interior. But when the air in the interior is pumped out by means
of an air-pump, the hemispheres cannot be separated without a powerful
effort.
_The Barometer is an instrument to measure the weight of the
atmosphere_, and thereby to indicate the variations of the weather,
etc. It consists of a long glass tube, about thirty-three inches in
length, closed at the upper end, and filled with mercury. The tube is
then inverted in a cup or leather bag of mercury, on which the pressure
of the atmosphere is exerted. The following experiment, which was first
made in 1643, by Torricelli, a pupil of Galileo, gives an exact measure
of the weight of the atmosphere.
[Illustration: FIG. 334.]
A glass tube is taken, about a yard long and a quarter of an inch
internal diameter, Fig. 334. It is sealed at one end, and is quite
filled with mercury. The aperture, C, being closed by the thumb, the
tube is inverted, the open end placed in a small mercury trough, and
the thumb removed. The tube being in a vertical position, the column of
mercury sinks, and, after oscillating some time, it finally comes to
rest at a height, A, which at the level of the sea is about 30 inches
above the mercury in the trough.
The mercury is raised in the tube by pressure of the atmosphere on the
mercury in the trough. There is no contrary pressure on the mercury in
the tube, because it is closed; but, if the end of the tube be opened,
the atmosphere will press equally inside and outside the tube, and the
mercury will sink to the level of that in the trough. It has been shown
that the heights of two columns of liquid in communication with each
other are inversely as their densities; and hence it follows that the
pressure of the atmosphere is equal to that of a column of mercury the
height of which is 30 inches. If, however, the weight of the atmosphere
diminishes, the height of the column which it can sustain must also
diminish.
_Why a vacuum gauge is graduated in inches instead of in pounds is thus
explained._ Take a tube say 35 inches long, closed at one end, filled
with mercury and inverted with its open end in a bowl containing the
same liquid.
The atmosphere will exert on the surface of the mercury in the bowl
a pressure of about 15 pounds per square inch and this pressure will
be transmitted to that in the tube so that the upward pressure inside
the tube at the level of the mercury in the bowl will be 15 pounds per
square inch.
Below the surface the pressure increases, due to the depth of mercury,
but the weight of mercury inside the tube below the level in the bowl
counteracts the weight of that outside so that the upward pressure per
square inch at the surface line is 15 pounds per square inch inside the
tube no matter how much or little it is submerged. In the upper end of
the tube the mercury has dropped away, leaving a complete vacuum.
NOTE.—Moreover it has the advantage over a scientifically graduated
gauge, which would be graded at 0 for a perfect vacuum and 15, or
more nearly 14.7, for atmospheric pressure, that the inch indication
increases as the vacuum is more complete while the absolute pressure
decreases. The inch of mercury has also the advantage over the pound
as a unit for measuring the degree of vacuum or the difference
between the pressure in the condenser and that of the atmosphere that
_there are twice as many inches in a perfect vacuum as there are
pounds_ so that the gauge can be read more closely without fractional
units. It is easier to say 23 inches than eleven and a half pounds.
The 15 pounds will force the mercury up into the tube until the column
is high enough to balance that pressure. One cubic inch of mercury
weighs about half a pound. It would take two cubic inches to weigh a
pound and a column two inches high to exert a pressure of one pound per
square inch of base, or a column 30 inches high to balance the pressure
of 15 pounds.
[Illustration: FIG. 335.]
[Illustration: FIG. 336.]
If instead of a perfect vacuum there was a pressure of two pounds in
the upper end of the tube the column would have to balance a pressure
of 15-2 = 13 pounds and would be 26 inches high. As the absolute
pressure in the top of the tube gets greater, that is to say, as the
difference between that pressure and that of the atmosphere or the
so-called vacuum gets less, the column of mercury gets lower, and its
height is a measure of the completeness of the vacuum.
_Hero’s fountain_, which derives its name from its inventor, Hero, who
lived at Alexandria, 120 B.C., depends on the elasticity of the air.
It consists of a brass dish, D, Fig. 335, and of two glass globes, M
and N. The dish communicates with the lower part of the globe, N, by
a long tube, B; and another tube, A, connects the two globes. A third
tube passes through the dish, D, to the lower part of the globe, M.
This tube having been taken out, the globe, M, is partially filled with
water; the tube is then replaced and water is poured into the dish. The
water flows through the tube, B, into the lower globe, and expels the
air, which is forced into the upper globe; the air, thus compressed,
acts upon water, and makes it jet out as represented in the figure.
If it were not for the resistance of the atmosphere and friction, the
liquid would rise to a height above the water in the dish equal to the
difference of the level in the two globes.
_The fountain in vacuo_, Fig. 336, shows an interesting experiment
made with the air-pump, and shows the elastic force of the air. It
consists of a glass vessel, A, provided at the bottom with a stop-cock,
and a tubulure which projects into the interior. Having screwed this
apparatus on the air-pump, it is exhausted, and the stop-cock being
closed, it is placed in a vessel of water, R. By opening the stop-cock,
the atmospheric pressure upon the water in the vessel makes it jet
through the tubulure into the interior of the vessel, as shown in the
drawing.
NOTE.—_Reference is hereafter very largely made to the mechanical
use of air as a moving power_, or rather as a means for transferring
power, just as it is transferred by a train of wheelwork. Compressed
air can be employed in this way with great advantage in mines,
tunnels, and other confined situations, where the discharge of steam
would be attended with inconvenience. The work is really done in
these cases by a steam-engine or other prime mover in compressing
the air. In the construction of the Mont Cenis tunnel the air was
first compressed by water-power, and then carried through pipes into
the heart of the mountain to work the boring machines. This use of
compressed air in such situations is also of indirect advantage
in serving not only to ventilate the place in which it is worked,
but also to cool it; for it must be remembered that air falls in
temperature during expansion, and therefore, as its temperature in
the machines was only that of the atmosphere, it must, on being
discharged from them, fall far below that temperature. This fall
is so great that one of the most serious practical difficulties in
working machines by compressed air has been found to be the formation
of ice in the pipes by the freezing of the moisture in the air, which
frequently chokes them entirely up.
ON GASES.
Gases are bodies which, unlike solids, have no independent shape, and,
unlike liquids, have no independent volume. Their molecules possess
almost perfect mobility; they are conceived as darting about in all
directions, and are continually tending to occupy a greater space. This
property of gases is known by the names _expansibility_, _tension_, or
_elastic force_, from which they are often called _elastic fluids_.
Gases and liquids have several properties in common, and some in which
they seem to differ are in reality only different degrees of the same
property. Thus, in both, the particles are capable of moving; in gases
with almost perfect freedom; in liquids not quite so freely, owing to
a greater degree of viscosity. Both are compressible, though in very
different degrees.
If a liquid and a gas both exist under the pressure of one atmosphere,
and then the pressure be doubled, the water is compressed by about
the 1/20000 part while the gas is compressed by one-half. In density
there is a great difference; water, which is the type of liquids, is
770 times as heavy as air, the type of gaseous bodies, while under
the pressure of one atmosphere. A spiral spring only shows elasticity
when it is compressed; it loses its tension when it has returned to
its primitive condition. A gas has no original volume; it is always
elastic, or in other words, it is always striving to attain a greater
volume; this tendency to indefinite expansion is the chief property by
which gases are distinguished from liquids.
[Illustration: FIG. 337.]
Matter assumes the solid, liquid, or gaseous form according to the
relative strength of the cohesive and repulsive forces exerted between
their molecules. In liquids these forces balance; in gases repulsion
preponderates.
By the aid of pressure and of low temperatures, the force of cohesion
may be so far increased in many gases that they are readily converted
into liquids, and we know now that with sufficient pressure and cold
they may all be liquified. On the other hand, heat, which increases the
_vis viva_ of the molecules, converts liquids, such as water, alcohol
and ether or gas into the aëriform state in which they obey all the
laws of gases. The aëriform state of liquids is known by the name of
_vapor_, while gases are bodies which, under ordinary temperature and
pressure, remain in the aëriform state.
In describing exclusively the properties of gases, we shall, for
obvious reasons, refer to atmospheric air as their type.
_Expansibility of Gases._ This property of gases, their tendency to
assume continually a greater volume, is exhibited by means of the
following experiment:—A bladder, closed by a stop-cock and about half
full of air, is placed under the receiver of the air pump, Fig. 337,
and a vacuum is produced, on which the bladder immediately distends.
[Illustration: FIG. 338.]
This arises from the fact that the molecules of air flying about in
all directions press against the sides of the bladder. Under ordinary
conditions, this internal pressure is counterbalanced by the air in the
receiver, which exerts an equal and contrary pressure. But when this
pressure is removed, by exhausting the receiver, the internal pressure
becomes evident. When air is admitted into the receiver, the bladder
resumes its original form.
_The compressibility of gases_ is readily shown by the _pneumatic
syringe_, Fig. 338. This consists of a stout glass tube closed at one
end, and provided with a tight-fitting packed piston. When the rod of
the piston is pressed down in the cube, the air becomes compressed into
a smaller volume; but as soon as the force is removed the air regains
its original volume, and the piston rises to its former position.
_Weight of Gases._ From their extreme fluidity and expansibility, gases
seem to be uninfluenced by the force of gravity: they nevertheless
possess weight like solids and liquids. To show this, a glass globe
of 3 or 4 quarts’ capacity is taken, Fig. 339, the neck of which is
provided with a stop-cock, which hermetically closes it, and by which
it can be screwed on the plate of the air-pump.
The globe is then exhausted, and its weight determined by means of a
delicate balance. Air is now allowed to enter, and the globe again
weighed. The weight in the second case will be found to be greater than
before, and if the capacity of the vessel is known the increase will
obviously be the weight of that volume of air.
When the atoms or particles which constitute a body are so balanced
by a system of attractions and repulsions that they resist any force
which tends to change the figure of the body, they will possess a
property, known by the name of elasticity. _Elasticity, therefore, is
the property which causes a body to resume its shape after it has been
compressed or expanded._
[Illustration: FIG. 339.]
_Pressure exerted by Gases._ Gases exert on their own molecules, and
on the sides of vessels which contain them, pressures which may be
regarded from two points of view. First, we may neglect the weight of
the gas; secondly, we may take account of its weight. If we neglect the
weight of any gaseous mass at rest, and only consider its expansive
force, it will be seen that the pressures due to this force act with
the same strength on all points, both of the mass itself and of the
vessel in which it is contained.
It is a necessary consequence of the elasticity and fluidity of gases
that _the repulsive force between the molecules is the same at all
points, and acts equally in all directions_.
If we consider the weight of any gas, we shall see that it gives rise
to pressures which obey the same laws as those produced by the weight
of liquids. Let us imagine a cylinder, with its axis vertical, several
miles high, closed at both ends and full of air. Let us consider any
small portion of the air enclosed between two horizontal planes. This
portion must sustain the weight of all the air above it, and transmit
that weight to the air beneath it, and likewise to the curved surface
of the cylinder which contains it, and at each point in a direction at
right angles to the surface. Thus the pressure increases from the top
of the column to the base; at any given layer it acts equally on equal
surfaces, and at right angles to them, whether they are horizontal,
vertical, or inclined.
The pressure acts on the sides of the vessel, and it is equal to the
weight of a column of gas whose base is this surface, and whose height
its distance from the summit of the column. _The pressure is also
independent of the shape and dimensions of the supposed cylinder_,
provided the height remain the same.
For a small quantity of gas the pressures due to its weight are quite
insignificant, and may be neglected; but for large quantities, like the
atmosphere, the pressures are considerable, and must be allowed for.
_Diffusion of gases._—Liquids mixed together, gradually separate, and
lie superimposed in the order of their densities, and the surfaces of
the separation of the liquids are horizontal. But when gases are mixed,
they present other conditions of equilibrium, as follows.
1.—A homogeneous and persistent mixture is formed rapidly, so that all
parts of the same volume are composed of the same proportions of the
mixed gases.
2.—In a mixture of gases, the pressure (or elastic force), exercised by
each of the gases, is the same as it was when alone.
3.—The rapidity with which the diffusion takes place, varies with the
specific gravity of the gases. The more widely two gases differ in
density, the quicker the process of intermixture.
_Evaporation._—This is the slow formation of vapor from the surface
of a liquid. The elastic force of a vapor which saturates a space
containing a gas (like air), is the same as in a vacuum. The principal
causes which influence the amount and rapidity of evaporation are as
follows.
1st.—_Extent of a surface._ As the evaporation takes place from the
surface, an increase of surface evidently facilitates evaporation.
2d.—_Temperature._ Increasing the elastic force of vapor, has a most
important influence on the rapidity of evaporation; therefore the
temperature of ebullition marks the maximum point of evaporation.
3d.—_The quantity of the same liquid already in the atmosphere_
exercises an important influence on evaporation. The atmosphere can
absorb only a certain amount of vapor, and evaporation ceases entirely
when the air is saturated, but it is greatest when free from vapor,
that is perfectly dry.
4th.—_Renewal of the air._ If currents of air are continually
removing the saturated atmosphere from above the surface of a liquid,
evaporation takes place most rapidly, since new portions of air,
capable of absorbing moisture, are presented to it. Evaporation is
therefore more rapid in a breeze than in still air.
5th.—_Pressure on the surface of the liquid influences evaporation_,
because of the resistance thus offered to the escape of the vapor. That
is to say—water boils more freely in an open vessel than within a steam
boiler under pressure. Hence, the necessity for having large steam
disengaging surfaces to prevent priming or lifting of the water when
the boiler is forced beyond its rated capacity.
HAND AIR PUMPS.
The use of compressed air has become very general through the use of
small hand pumps; the cylinder of these must be smooth, and the plunger
is usually packed with a cup leather packing.
[Illustration: FIG. 340.—Gas Fitter’s Proving Pump.]
Fig. 340 shows a _gas fitter’s air proving pump_. The gauge is attached
to any opening into the system of pipes to be tested, with a rubber
hose leading to the pump. By working the pump the air is forced into
the pipes; upon stopping the pump if the hand upon the gauge remains
stationary there are no leaks in the system. If there are leaks the
hand of the gauge will gradually return to the zero mark.
NOTE.—Before putting the pressure on it is customary to put some
ether into the small cup—near the gauge as shown—this has a cock
which must be opened and closed at the proper time so that the ether
will be forced into the pipe system and disclose by the sense of
smell the location of the leak.
Fig. 341 shows a _Portable Tire Air Pump_, which can be used by hand
or affixed to a wall or bench; it is of the lever type, with 2 × 8
cylinders, fitted with check valve and extra heavy rubber tubing.
As the leverage on the piston-rod increases the resistance on the
piston also increases, thereby securing the powerful leverage of the
well-known “toggle-joint” principle as the piston finishes its stroke;
thus the best possible results are obtained.
Fig. 342 illustrates a _Hand Lever Air Pump_ with cylinder 3-1/4″
× 6-1/4″; its capacity—one stroke—is 36 cubic inches. The greatest
pressure it is intended to operate against is 150 lbs. to the square
inch. In operation this design has the advantage of the leverage of the
toggle-joint indicated above.
Fig. 343 exhibits a Hand Air Pump which has the same dimensions as that
just described, screwed to the floor. Its particular advantage is the
fact that the motion of the lever is natural and easy being horizontal
and still retaining the advantages of the toggle-joint.
[Illustration: FIG. 341.—Hand Pump.]
[Illustration: FIG. 342.]
[Illustration: FIG. 343.]
AIR AND VACUUM PUMPS.
_An air pump_ is an apparatus for, 1, the exhaustion; 2, compression or
transmission of air.
_A vacuum pump_ is an apparatus consisting of, 1, a chamber or barrel;
2, a suction pipe with a valve to prevent return flow; 3, a discharge
pipe which has a valve which is closed when the chamber is emptied and,
4, a steam induction pipe provided with a valve that is opened when the
chamber is filled with water and closed when the chamber is filled with
steam.
It is not right to call an air pump a vacuum pump, _as the latter does
not move_ air alone; it removes water, vapor and air from the condenser
to form a vacuum. An air pump is designed to pump air alone.
_A vacuum is a space entirely devoid of matter._ That is, it is a space
that contains nothing—no oxygen, no hydrogen, no air, no water, no
pressure. It is for this reason that a perfect vacuum in practice is
very difficult to obtain, especially as applied in a steam engine, as a
liquid when in the presence of a vacuum generally gives off some vapor,
owing to the fact that the surface is more or less in tension, besides
its usual evaporative quality. Among all the liquids it has been found
that mercury, on account of its very high specific gravity, can be best
used to produce a vacuum and maintain it, and it is for this reason
that the words “vacuum” and “inches of mercury” are synonymous.
NOTE.—The pressure of the atmosphere will also balance a column of
water in a vacuum the same as a column of mercury but the height of
the water column must necessarily be greater on account of the lesser
weight of the water. A cubic inch of water weighs 13.6 times less
than a cubic inch of mercury, so that the column of water which the
atmosphere must balance must be 13.6 higher or 13.6 × 30 = 408 inches
which is equivalent to 34 feet.
_A water barometer_ can be made in a similar manner to a mercury
barometer except that instead of a tube slightly over 30 inches in
length, a tube over 34 feet in height must be used. Advantage of this
fact is taken in the so-called gravity condensers which require no
air pump, the condensing apparatus being placed about 34 feet above
the level of the hot well, the discharge pipe being sealed by always
keeping its lower end below the level of the water in the hot well.
The particular feature that makes steam valuable in producing a vacuum
is the fact that when it is condensed, it decreases 1600 times in
volume and except for this small quantity of water and some vapor
which even cool water gives off in a vacuum, a perfect vacuum would be
established and it is only necessary to draw off the condensed steam
and vapor by proper apparatus to enable the vacuum to be maintained
which the condensation has created. The apparatus for doing this is
called the air pump _and the reservoir in which this condensation takes
place is called the condenser_.
The condensation of steam in the condenser is effected in two ways.
The exhaust steam either meets in direct contact the water which is to
condense it, or, the steam impinges upon cool metallic surfaces the
temperature of which is kept down by circulating cool water through
them. In the first case the condensed steam and the condensing water
meet and mingle. The condenser is an iron pot or shell into which the
steam is exhausted and the cooling water enters it in the form of a
sheet or spray. Such condensers are called _jet condensers_ for this
reason, and the cooling water is called _the injection_. All water that
is used for condensing steam is therefore called _the injection water_.
When the exhaust steam strikes cool surfaces and is condensed by
those surfaces, such condenser is called _a surface condenser_. The
cooling surface is usually a series of pipes or tubes made of brass
or copper to secure a rapid transfer of heat. These tubes are usually
tinned inside and outside to prevent corrosion and in marine practice
are made 5/8″ in diameter. In most cases, condensation is effected by
bringing the exhaust steam in contact with the outside of the tubes,
the circulating water being inside.
_In the surface condenser_, as the circulation does not mingle with the
condensed steam, the air pump has nothing to do with this water but is
only required to pump out the condensed steam and air which enter the
condenser; the pump which takes care of the circulation is called _the
circulating pump_. When large quantities of water are used and the
difference in level through which the water must be raised is slight as
on board ship, _centrifugal pumps_ are generally used.
_In the jet type of condenser_ where the water acts directly on the
steam, the injection water will cause a lower temperature with less
water and less apparatus than a surface condenser. The amount of
injection water varies from 20 to 30 times the weight of steam to be
condensed in cool seasons and from 30 to 35 times the amount in summer
season. With fresh water this can be pumped into the boiler when the
oil is extracted from it. It is for this reason that surface condensers
are universally used for sea-going vessels to avoid salt water. They
are also much used on land in places where the feed water contains
mineral salts and is injurious to the boiler.
In places where the cost of hydrant water is excessive, it is of
importance to use the same injection water over and over again,
but this cannot be done until the water is first cooled. There are
numerous methods by means of which this is done. All of these methods
utilize the principle of scattering the injection water in the way
best calculated to bring the greatest surface in contact with the
largest quantity of air so that evaporation may take place quickly and
effectively.
This is sometimes done by pumping the water through a number of spray
nozzles up into the air, allowing it to fall into a lake or cold well
below, or, as is more usually the case, the injection water is allowed
to descend in a tower in a fine state of division over tiles or wire
gauze or corrugated surfaces. A current of air, either forced by a
fan or drawn up through it, causes a vaporization of the film of warm
water pouring over the different surfaces, and the air cooling and the
evaporation combined withdraw the heat from the water so that when it
reaches the bottom it is in condition to be used again.
[Illustration: FIG. 344.]
[Illustration: FIG. 345.]
Cooling towers are used with either jet or surface condensers and can
be used either with or without a fan, depending upon the design. In
general these towers usually lower the temperature of the water from
120 degrees to 80 degrees, which is sufficient to maintain a vacuum of
about 26 inches. As they depend chiefly upon the results of evaporation
to do the cooling, they work better on a dry day than when the air is
humid.
The figures on the opposite page are designed to illustrate the use of
_an air pump in connection with a jet condenser_; this combination is
properly called a vacuum pump because it not only pumps air, but water
and vapor as well. The _steam end_ of this apparatus is described in
Part One, page 324, of this work.
_The air and vacuum end_ has a cylinder lined with composition-brass
bored smooth; the piston has square rubber and canvas packing. The
discharge—as shown in cut—is located sufficiently high, so that the
cylinder retains a large portion of water. This forms a seal and
causes the pump to work more advantageously than it would with air
alone. A small pipe leads from the discharge chamber to the piston-rod
stuffing-box. This contains a double packing and the water which flows
through this small pipe forms a continuous seal around the piston-rod
and thus prevents air from entering.
The injection water enters the elbow at the top and is drawn through an
annular opening into the condenser. This opening may be regulated by
the small hand wheel shown at the top end of the stem.
The exhaust from the steam end flows into the condenser through the
pipe as may readily be observed—or escapes into the atmosphere by
throwing the switch valve.
NOTE.—_Utilizing hot discharge water._ In manufacturing
establishments where large quantities of water are required,
advantage can be taken of the fact that in condensing apparatus of
this and similar pumps, the water, after performing useful work in
the condensing chamber, can be elevated to a tank in any portion of
the building, _and used over again for another purpose_, such as
washing, cooling metal plates, rolling-mill rolls, etc. The fact that
the temperature of this discharge water will range from 100° to 120°
will, in many cases, be advantageous, and effect a saving in the cost
of heating other water for purposes in which this discharge water
will answer equally well. _When the water is not required in the
tank, the stop-valve may be opened, and the water allowed to escape
into a drain, or any other convenient place._
A ball-float attached to an air valve is located at the right hand of
the condenser so that in case the pump should fail to operate from any
cause, the injection water will lift the ball-float, which in turn
will open the air valve and by discharging the vacuum will prevent the
flooding of the engine cylinder with water.
It is a well-known fact that the atmosphere exerts what is usually
termed “back pressure” of 14.7 pounds per square inch upon the piston
area of a steam engine, also that water converted into steam, may
be converted into its original state by condensation. Now, if this
back pressure, which is, in reality, the weight of the surrounding
atmosphere, be removed from the piston of a steam engine, the steam on
the opposite side of the piston would have that much (14.7 lbs.) less
work to do.
Applying this to steam engines means conveying the exhaust, or expanded
steam, which would otherwise be allowed to escape into the open air,
into a closed chamber, where it is met by a spray of cold water, which
so rapidly absorbs the heat contained in the steam that it ceases to
retain its gaseous form, and is again reduced to its original bulk as
water. A great change has now taken place, and the steam is reduced
to its liquid form. As this water of condensation only occupies about
1/1600 of the space filled by the steam from which it was formed, the
remainder of the space is vacant, and no pressure exists.
The difference in volume accounts for the atmospheric pressure on the
outside of the chamber, and as the vacuum extends throughout the whole
distance which the exhaust steam originally occupied, it, of course,
is made available in the cylinder of the engine in the shape of a
decreased pressure on the exhaust side of the piston; the atmospheric
pressure remains constant, therefore we have the atmospheric pressure
acting on one side of the piston, and absent on the other; the gain
being 14.7 pounds per square inch, if a perfect vacuum could be
secured. It amounts in average engineering practice to from 12 to 13
pounds, or 24 to 26 inches of mercury, as the graduations usually read
on vacuum gauges.
Jet and Surface Condensers are further described and illustrated in a
special allotted section of this work. The vacuum pump is usually of
the reciprocating order, although other methods have been employed for
emptying condensers, but not with equally satisfactory results.
_The gain to be secured by using a condensing apparatus_ may be
measured in two ways: first, by the decrease in fuel consumption over
that necessary when running non-condensing, which will represent a
constant decrease in running expenses; or, second, by the increase of
power working quite up to its economical limit, in a non-condensing
engine.
By the use of a condenser a further increase of power is realized in
raising the mean effective pressure of steam within the engine cylinder
without increasing the demand upon the boiler.
_The application of a condenser to a steam engine_ increases its
economy from 20% to 25% depending upon circumstances, while by
compounding and condensing an economy of 35% to 40% is effected.
SINGLE AND CROSS COMPOUND DOUBLE ACTING VACUUM PUMPS.
_The vacuum pump_ shown in the engraving, Fig. 346, represents a single
cylinder double acting vertical design having but one set of valves and
those used exclusively for the discharge.
The suction port is in the middle of the cylinder, A, shown in the
sectional view, Fig. 347. The piston, E, when it passes this port
imprisons the water beyond it and pushes this water out of the
discharge valves, D D, if the piston is rising, and out of the valves,
C C, if the piston is descending. The main discharge pipe is attached
to a flange at B.
This pump is made to work easily and steadily by adjusting the
cushioning valves, F. F.
The discharge valves are reached through the holes provided for that
purpose and covered by plates shown in the engraving, Fig. 347.
The main slide valve moves horizontally for the reason that if it moved
up and down the force of gravity would seriously interfere with its
regular action.
This slide is moved by a valve piston in the usual way. The parts of
the valve may be inspected and adjusted by removing the cover held by
the two studs shown.
The outline engraving, Fig. 348, shows a cross-compound double acting
vacuum pump, six-inch high pressure, nine-inch low pressure cylinders,
by eight-inch stroke, and two air cylinders, ten-inch diameter by
eight-inch stroke.
They are piped up to run either high or low pressure, also to run
independently by manipulating the cocks, C, and D, _as directed in the
engraving showing arrangement of valves_, Fig. 349, page 41.
[Illustration: FIG. 346.]
These pipes are simple in design and run direct to the boiler for live
steam and convey the exhaust to the atmosphere or condenser as desired.
On a recent test at a fair rate of speed the capacity of this pump was
shown to be equivalent to taking care of a triple expansion engine of
2,000 I. H. P. On a further test this same pump on a basis of 20 lbs.
weight of steam per I. H. P. per hour demonstrated its ability to take
care of 3,000 I. H. P. triple expansion engine.
The advantages claimed for this pump are briefly as follows:
Unusual light weight and compactness.
There being NO SUCTION VALVES, working-beams, rock shaft and bearings,
beam-links, etc., this pump is simple.
It is economical in the use of steam, by reason of compounding the
steam cylinders; also clearance loss is reduced to a minimum by the
perfect regulation that is secured by the valve gear described. Full
stroke at any and all speeds can be readily maintained.
As the air pistons travel within a distance of less than 1/8 inch
of the air cylinder heads, a high efficiency results. Although
double-acting, the flow of water and vapors is always in one continuous
direction—the same as in a single-acting air pump. Either side of pump
can run independent of the other, which means a spare pump to be used
in case of accident to the other side of this pump.
[Illustration: FIG. 347.]
[Illustration: FIG. 348.]
Referring to the accompanying table of tests, page 41, it may be
claimed that with an average of 36 double strokes per minute this pump
handled at the rate of upwards of 26,000 pounds of feed-water per
hour, which on a basis of 20 lbs. engine economy shows this vacuum
pump capable of taking care of a 1,300 I. H. P. engine at this very
moderate speed. By comparing the power required to drive this pump
(which aggregated 1.18 I. H. P.) to the I. H. P. of an engine of the
power here represented it is apparent that this pump did its work on
less than one-eleventh of one per cent. of the I. H. P. of said engine,
which is a very excellent showing.
[Illustration: FIG. 349.—See page 38.]
Table No. 4 also shows a very excellent vacuum maintained under extreme
duty.
TABLE.
==========================+=========+==========+=========+========
NUMBER OF TEST. | No. 1. | No. 2. | No. 3. | No. 4.
--------------------------+---------+----------+---------+--------
Steam pressure—high | 70 | 120 | 125 |
steam cylinder | lbs. | lbs. | lbs. | --
| | | |
Steam pressure—low steam | | | |
cylinder | 20 lbs. | 40 lbs. | 45 lbs. | 50 lbs.
| | | |
Vacuum in condenser |27-1/2in.| 27in. |26-1/4in.| 25in.
| | | |
Double strokes per minute | | | |
—high side | 37 | 61 | 82 | --
| | | |
Double strokes per minute | | | |
—low side | 35 | 60 | 82 | 88
| | | |
Temperature of hot well— | 106 | 105 | 108 | 112
Fahrenheit | deg. | deg. | deg. | deg.
| | | |
Water pumped per hour— | 13,500 | 22,700 | 30,000 |
high side | lbs. | lbs. | lbs. | --
| | | |
Water pumped per hour— |12,700 |22,300 |30,200 |36,000
low side | lbs. | lbs. | lbs. | lbs.
| | | |
Total water per hour | 26,200 | 45,000 | 60,200 | --
| lbs. | lbs. | lbs. |
| | | |
I. H. P. of high steam | | | |
cylinder | 0.60 | -- | -- | --
| | | |
I. H. P. of low steam | | | |
cylinder | 0.58 | -- | -- | --
Total I. H. P. | 1.18 | -- | -- | --
--------------------------+---------+----------+---------+------
[Illustration: FIG. 350.]
_The Deane Vacuum Pump._ There are a number of novel features exhibited
in the construction of this pump; the cylinder has four ports, that is
to say _two steam or admission ports and two compression or cushioning
ports_.
Referring to the engraving, page 42, Fig. 6, shows the main valve to
be a plain ^D^ slide,—directly under it the same valve is shown in
section. The projection on the back of this valve fits into the valve
piston. The secondary valve, 5, surrounds the main valve and contains
two plain slide valves, one on each side. Referring to 3, it will be
noted that one of these valves admits steam while the other allows the
steam to escape after having done its work of moving the valve piston.
A longitudinal section of this secondary valve and steam cylinder are
shown, in 2.
In the engraving, 1, it is shown that the cylinder for each end of the
valve piston is jacketed with live steam so that the cylinder itself
heats up as quickly as the valve piston, hence the piston cannot stick
in the cylinder due to unequal expansion of valve and seat.
The supplemental valve ports are shown in section 4.
_To set the valve of this pump_: Remove the steam chest, place the
piston at mid stroke with the lever, plumb, then set the stem at its
mid position with the secondary valve in place. See that the tappets
measure equal distances either side of the tappet block.
NOTE.—These small ports are not liable to fill with oil and dirt in
practice, on account of their direct connections. If through leakage
or any other reason the valve piston should fail to throw the main
slide valve, the projection B (see 1) on the valve stem (of which it
is a part) compels the valves to move mechanically. So when steam is
turned on, this pump is certain to begin its work.
[Illustration: FIG. 351.]
The water end of this pump consists of a cylinder with valve chambers
as shown. The piston rod has two stuffing-boxes, which makes a water
seal around the rod so that no air can enter the cylinder, as the
chamber between the two stuffing-boxes is kept constantly filled with
water. It will be noticed that the suction pipe enters the pump
in such a position in relation to the valves that both suction and
discharge valves are perpetually immersed in water.
When this pump is pumping air only, there is sufficient water left
within the valve chambers to provide a water seal under all working
conditions. The valves in this pump are easily reached for inspection
or repairs, a hand-hole being provided for each valve, with proper
covers, which are easily and quickly replaced.
_The Worthington Vertical Beam Vacuum Pump_ with condenser attached is
shown in Fig. 351.
This is a pump of great simplicity and strength. The figure shows _a
compound engine_ for using high pressure steam; these machines can be
built with simple steam cylinders of equal diameters, but they are
not recommended except in special cases; for example where the steam
pressure is very low. Each side of the pump end is single-acting, the
buckets being of the form used for years in detached air pumps in
marine service. The two sides are connected together by a beam and
links attached to the cross-heads. As one side comes down and does
little work, the other side makes an up-stroke and does full duty in
emptying the condenser to which the suction is attached.
The condensing chamber is usually placed at the rear and connects
directly with the channel plate at the bottom of the pump. The opening
shown in front is for the discharge water.
The steam cylinders are so arranged that either piston may be examined
by removing its cylinder head, without disturbing the other cylinders.
The valves are of the Corliss, or semi-rotative, type and the
high-pressure cylinders are provided with cut-off valves to assure the
desired ratio of expansion.
The interior of each air cylinder may be inspected by removing the
plates shown in front, near the middle. There are also two plates at
the top for inspection of the discharge valves. The four machinery
steel columns form a light but very strong frame allowing free access
to the working parts.
[Illustration: FIG. 352.]
The next four cuts show Dean Brothers’ twin cylinder air pumps with
their special steam valve gear. They are made for and supplied with
either surface or jet condensers. See Fig. 352.
The arrangement of the valve gear is such that steam will be applied at
the upper end of one piston at the same instant that it begins to act
on the lower end of the other. By this device steam is so controlled in
the steam chests that no pressure comes on the main pistons, until the
moment that both are ready to move, after having reached the full limit
of their stroke, thereby securing an exactly uniform, but opposite,
motion of the pistons. Fig. 354 is a sectional elevation of the steam
cylinder and steam chest; Fig. 353, a front elevation; Fig. 355, a
section of the air cylinder, and Fig. 352, an exterior perspective view
of the pump.
Each steam cylinder has its own steam piston, piston rod, valve
movement, steam chest, etc. A sleeve, _a_, is rigidly attached to each
piston rod, and connected to this sleeve is a lever, _b_, the outer
end of which connects with a link, _c_, which in turn is connected to
a sleeve, _d_, loosely mounted upon the valve rod between collars,
_e_. The valve rod, _f_, operates the auxiliary slide valve and admits
the steam from above and below the auxiliary piston. This piston has
attached thereto the main slide valve, which admits and exhausts steam
alternately from above and below the main steam pistons. Any movement
of the main piston communicates movement in the opposite direction to
the sleeve, _d_, which moves the valve rod only when it strikes one or
the other of the collars. As there is considerable lost motion between
the sleeve and the collars, the main steam piston will be nearing the
end of its stroke when the valve rod begins to move.
[Illustration: FIG. 353.]
Extending through the ends of the steam chests are short piston rods,
_g_, which are connected to a centrally pivoted vibrating lever, _h_,
mounted on a pivot. When the main steam piston has moved from the top
to the bottom of the steam cylinder, the corresponding valve rod has
moved in the opposite direction and the auxiliary slide valve has
moved upward, opening the port, _i_, to steam and the port, _k_, to
the exhaust port. At the moment the main steam piston has completed
its downward stroke the auxiliary piston is forced upward and carries
with it the main slide valve, _l_. This opens the main steam port and
exhaust port, which reverses the movement of the main piston. When the
main piston reaches the upward limit of its stroke the auxiliary valve
has moved downward, opening the port, _k_, to steam and the port, _i_,
to the exhaust, causing the auxiliary piston to move downward, thus
reversing the movement of the main valve and piston.
By this arrangement the valve operating piston, _m_, is held at all
times immovably at one end of the stroke, except when the main piston
is nearing the end of its stroke and is ready to reverse. Supposing
the left-hand main piston has not quite reached the upper limit of the
stroke, the steam would still be on the lower side of its auxiliary or
main valve operating piston and the exhaust open to the other side. We
now have steam on the bottom side of both auxiliary pistons, and as
they are of equal diameters and are connected by the lever, _h_, they
are balanced and cannot move the main steam valves. The right-hand main
steam piston must wait until the left-hand piston has completed its
stroke before it can reverse, and consequently the movement of the main
pistons will always be in opposite directions, and neither can reverse
until both have completed their stroke.
[Illustration: FIG. 354.]
[Illustration: FIG. 355.]
There are three ways that this apparatus may be operated: First,
the pumps may be operated in conjunction with each other, as is
hereinbefore described. Second, the lever, _h_, may be detached from
the auxiliary or main valve operating pistons, and the two pumps may
then run independently of each other or in the ordinary and well-known
manner, each performing its own independent work. Third, by further
detaching the link, _c_, on one of the valve gears the auxiliary slide
valve, _n_, will remain at rest and the corresponding pump will not
move while the other pump continues to operate. These are important
features, because, as in case of accident, it may be necessary to
use one pump while the other is disabled, and in some cases it may
be desirable to operate the pumps independently. The engineer will
appreciate this feature, as the stoppage of an air pump is a serious
matter.
The piston rods are separable at the crossheads. The crossheads are
of steel. The steam cylinders and pump cylinders are connected by
six heavy steel stretcher rods. Adjusting valves are fitted to steam
cylinders for controlling motion of pistons. The valve gear is provided
with a special lever adjustment by which the length of stroke of
pistons may at any time be changed, even while the pump is running.
In Fig. 356 is shown a form of independent vacuum pump, with its
condenser, built by the Conover Mfg. Co.
This apparatus consists of a jet condenser with air pump, boiler feed
pump, and engine to drive both, combined as one machine. The air pump
is a single acting bucket plunger pump, driven by a crank shaft, turned
by the engine, which is a single cylinder compound automatic cut-off
engine, and also drives the boiler feed pump; it is of the trunk
pattern, and the small space around the trunk on the top side of the
piston forms the high pressure cylinder. Steam is admitted to the high
pressure side, at boiler pressure, and is cut off and expanded and
exhausted into the receiver, whence it is admitted under the bottom
side of the piston, where it is again cut off and expanded, finally
exhausting into the condenser.
_The piston makes the down stroke when the air pump makes the up
stroke_; and it will be seen by referring to the cut that the engine
does nearly all its work when making the downward stroke. When steam is
acting on the top side of piston at high pressure, the vacuum at the
same time is pulling on the full area of the piston underneath.
[Illustration: FIG. 356.]
When the engine makes the up stroke, the steam at low pressure from the
receiver acts to push the piston up; and as the air pump is doing no
work then, being on its down stroke, the only work of the engine is to
keep the machine up to speed.
[Illustration: FIG. 357.]
It will thus be seen that the engine is suited to meet the demand of
the large power on one stroke, and very little on the other, thus
adapting itself admirably to its requirements.
The valves are of the Corliss type, and do not trip; the cut-off being
set by hand, does not require to be changed or altered, as the speed is
controlled by a throttling governor.
Fig. 357 shows a cross section through the steam cylinder of this
vacuum pump.
[Illustration: FIG. 358.]
_The Edwards air and vacuum pump_ is shown in Figs. 358, 359 and 360,
in which it may be perceived that both foot and bucket valves are
dispensed with; the only valves used are those which in other pumps are
known as head or discharge valves.
The following brief description of its leading features will be
understood by reference to the illustrations: Fig. 358 is a sectional
view through the center of the air pump, but the piston and rod are
shown as a full view.
The action of this pump is as follows: the condensed steam flows
continuously by gravity from the condenser into the base of the pump,
and is there dealt with mechanically by the conical bucket working in
connection with a base of similar shape. Upon the descent of the bucket
the water is projected silently and without shock at a high velocity
through the ports into the working barrel (see Fig. 359). The rising
water is followed by the rising bucket, which closes the ports, and,
sweeping the air and water before it, discharges them through the valve
at the top of the barrel.
[Illustration: FIG. 359.]
It may be said that however slowly an ordinary air pump with foot
and bucket valves may be running, the pressure in the condenser has
to be sufficiently above that in the pump to lift the foot valves,
overcome the inertia of the water, and drive the water up through the
valves into the barrel where the water is dealt with mechanically. The
higher the speed of the older type of pump the greater is the pressure
required to overcome these resistances owing to the very short space
of time available, and as any increase of pressure in the condenser is
accompanied by a corresponding increase of back pressure in the low
pressure cylinder, hence the absence of the valves referred to allows a
higher speed of the plunger. The elimination of the foot valves it is
claimed gives from 1/2 to 1 inch better vacuum.
[Illustration: FIG. 360.]
Another advantage claimed for this pump is that clear air inlets are
maintained—see Figs. 359 and 360. Under ordinary working conditions,
when the bucket descends and the ports open, there is no obstruction
between the condenser and the pump; the air has a free entrance while
immediately afterward the water is injected into the barrel at a high
velocity. Thus, instead of obstructing the entrance of the air, the
water tends to compress that already in the barrel, and to entrain or
carry in more air with it.
The bucket or piston is a hollow casting with water grooves instead of
packing rings.
The valve seat is constructed with a rib between each valve and a lip
around the outer edge, so that each valve stands in its own water and
is separated from the others. This forms a ready means of testing the
relative tightness of each valve.
The cast iron working barrel is lined with brass.
The pump rod is Tobin bronze, and valve plate and valves of
composition. These pumps are either single, twin, triplex, and are
steam, electric or belt driven, for stationary, marine or sugar
plantation service.
The steam driven pumps are built with either single or compound steam
cylinders, fitted with new and improved valve gear, and with their
arrangement of fly-wheels, insures smooth running, making full strokes
free from vibration.
[Illustration: FIG. 361.—See page 70.]
AIR COMPRESSORS.
_Compressed air_ is air compressed by mechanical force into a state of
more or less increased density. _The power obtained from the expansion_
of greatly compressed air in a cylinder, on being set free is used
in many applications as a substitute for steam or other force as in
operating drills, shop tools and _engines_ which are driven by the
elastic force of compressed air.
_A compressor_ is a machine usually driven by steam by which air is
compressed in a receiver so that its expansion may be utilized as a
source of power at distances where an ordinary engine could not be
conveniently used.
The compressor proper comprises two sets of valves, usually designed
to be opened automatically by excess of pressure under them and to
be closed by gravity or by the action of springs when the pressures
become equal. The inlet valves open just after the piston commences
its stroke, when the expansion of the compressed air remaining in the
cylinder behind the piston has lowered the pressure above the valves.
They close at the end of the intake stroke, just as the piston comes to
rest. The outlet valve lifts during the compression stroke, at about
the time the rising pressure in the cylinder becomes equal to that in
the outlet passage above the valves; and they close when the flow of
air ceases as the piston completes its stroke.
Any of the accurately fitted steam engine valve gears may be used for
compressors, observing only that the compressor is in every way a
reversed steam engine.
Compressed air is already used in the operation of
1. Cranes, hoists and motors of all types and of all capacities.
2. Portable drilling, reaming and tapping machines.
3. Riveters and stay-bolt cutters, calking and chipping tools.
4. Shop tools of all kinds.
5. Air brakes.
6. Sand blasts.
7. Rock drills and coal mining machines.
8. Pneumatic locomotives and street cars.
[Illustration: FIG. 362.—see page 70.]
and also for the following diversified uses,
1. Pumping water, sewage, oil and acids.
2. Raising sunken vessels.
3. Refrigerating and ice making.
4. Transmitting messages through pneumatic tubes.
5. Cleaning carpets and railroad cars and seats.
6. Sinking caissons and driving tunnels through silt and soft earth.
7. Tapping iron furnaces.
8. Transmitting power for all purposes.
_The office of the air compressor is to store up air under high
pressures_, which can be utilized at a greater or less distance,
without sustaining any loss by condensation in the pipes, as is the
case of carrying steam in pipes long distances.
Air stored under pressure in a reservoir can be used expansively, in an
ordinary steam engine returning an equivalent amount of work that was
required to compress it—less the friction.
The admission of the air being through a single tube, it creates a
constant flow of air in one direction only, thus filling the cylinder
at each stroke with air at atmospheric pressure. This movement gives a
momentum to the air which causes it to fill the cylinder to its fullest
extent at each stroke.
_Air compressors may be driven in various ways_, but the most commonly
used are those which are directly connected to a steam engine, thus
doing away with intermediate machinery. When the air piston draws in
a charge of air, the air fills the cylinder at atmospheric pressure,
or a little below, and on the return stroke of the piston it has to be
compressed to the same pressure as in the receiver before it can lift
the delivery valve, and as the valve is held to its seat by a spring,
and also by its own weight, the pressure has to be considerably above
that of the receiver before the valve will lift. To overcome this the
valves are operated by mechanical means, which lifts them at a point of
the stroke, when the pressure in the cylinder corresponds with that of
the receiver.
[Illustration: FIG. 363.—See page 71.]
This arrangement avoids pounding of the valves as well as the noise
caused by the air when rushing at much higher pressure from the
cylinder into the receiver.
For the sake of economy, air compressors are compounded, as for
example, by drawing the air into a large cylinder and compressing it
to a certain stage, whence it passes into a smaller cylinder, which
compresses it to a much higher pressure.
In a simple compressor, for very high pressures, there is at the end
of the stroke a large volume of air left in the clearance space, which
expands on the return stroke, to atmospheric pressure, before another
charge of air can be drawn in.
But in the compound compressor, the air is delivered from the low
pressure receiver to the high pressure cylinder far above atmospheric
pressure, thus the remaining air need not expand so much and allows the
cylinder to take a larger volume of air. The load is also distributed
more evenly.
The following are valuable “points” relating to the care and management
of air compressors.
As in a steam pipe line, elbows should be avoided in an air pipe line
but unlike a steam pipe it should be larger.
A mistake is sometimes made in purchasing a compressor built for a low
altitude and trying to run it in a higher elevation; the machine then
experiences the same trouble that some people do, in not being able to
get breath enough under the changed conditions.
The use of cheap oils, especially in an air cylinder is a most serious
mistake, as the least tendency to gum will prevent the valves from
properly seating, and even with the best of oils, it is well to use a
small amount of mineral oil at times.
In localities where the water is bad, the water jacket will require
extra attention, as it gets as badly scaled like steam boilers,
principally due to a very slow or retarded circulation, which allows
the sediment to settle, and should the water supply be shut off, even
for a few minutes, the cylinder heat will bake it so hard as to give
considerable trouble. It is a good plan to put a good boiler compound
in the water jacket, and run the machine for some time without any
circulation.
[Illustration: FIG. 364. (See page 71.)] In this case good judgment
must be used not to run too long or too fast, as the cylinder will heat
very quickly and is liable to be damaged.
There are many emergency ways of stopping small pipe leaks; any good
sticky substance, such as tar, wax, tallow candles, or even chewing
gum, melted and applied on narrow strips of cloth and wound as a
bandage, will be found handy.
It should be remembered that leaks in an air pipe line are as bad as in
a steam pipe line, and should receive as much care.
_The theoretical operation of air compressors may be thus explained_:
If a tight cylindrical vessel, containing one cubic foot of air at
atmospheric pressure, be fitted with a piston which is free to move up
and down but yet perfectly tight, the air in the vessel will have no
means of escape, and the pressure within and without the vessel, both
being atmospheric, are balanced.
Now, if the piston should be loaded with a weight, the pressure on the
outside would be that due to the atmosphere, plus the weight, while the
pressure from the inside is simply equal to atmospheric pressure; thus
the piston is forced to descend, but as the air inside of the cylinder
has no means of escape, the volume it fills being diminished, its
pressure rises until the pressure under the piston balances that above
it.
If, for example, the area of the piston should be 100 square inches,
and the weight with which it is loaded be 100 pounds, assuming the
piston to be without weight, the pressure below will have to react
with an equal force to hold the piston stationary, which in this case
would be 1 pound to the square inch above atmospheric pressure, and
the piston would have to descend sufficiently to cause this increase
of pressure, which descent would be equal to 1/16 of the total fall
of the piston. By adding another 100 pounds above, the pressure would
rise to 2 pounds to the square inch. The cylinder is thus charged with
compressed air.
_Liquid Air_ is a marvelous result of compression. It liquefies at a
pressure of 573 pounds per square inch, at the reduced temperature
of -220° F.; at atmospheric pressure it boils at-312° F., at which
temperature it can be handled like water. _Air_ is the vapor of a
liquid, and acts in its properties like the vapor of other liquids.
Liquid air in color is like that of a blue sky on a cloudless day.
[Illustration: FIG. 365. (See page 71.)]
“_Denys Papin_ was the first to propose and make, in 1653, an actual
trial of the transmission of power to a distance by compressed
air. It was the fertile and mechanical brain of Papin that first
conceived the idea of the pneumatic tube for transmitting parcels
by air pressure.” Historical Note by Hiscox.
If now the bottom of the cylinder should be connected by means of a
pipe to another vessel of larger capacity called a receiver, the pipe
having been closed by a valve in it during compression, and the valve
should be opened, the piston would at once commence a further descent,
the compressed air escaping into the receiver, until the pressure in
the receiver and cylinder is equalized, or the piston reaches the
bottom of the cylinder, which it will do, if the receiver is large
enough. Then the valve closes, stopping communication between cylinder
and receiver, and the piston is drawn upward; at the same time air is
again admitted to the cylinder by another valve, which closes when the
piston reaches the top, and the same operation is again repeated.
The receiver can thus be charged with compressed air and by loading the
piston very heavy the pressure can be raised quite high.
Now, if the piston, instead of being loaded by weights, be connected to
the piston rod of a steam engine, or by means of a connecting rod to a
crank (which is rotated by a belt or some other driving mechanism, and
the valves be operated automatically, as the valves on a water pump),
the simple apparatus is converted into a perfect air compressor, _which
really is nothing else than an air pump_, and the air can be pumped
into the receiver against a high pressure the same as water is forced
into an elevated reservoir by a pump.
As air is a compressible gas, it acts a little different in the air
cylinder from the almost incompressible water in a pump.
To lift the valves of an air compressor by the compressed air pressure
in the cylinder (added to the pressure of their springs besides the
receiver pressure), the air would have to be compressed considerably
above the receiver pressure before it would lift the valve which allows
it to flow from the cylinder into the receiver, and then the valve
would not open freely as a pump valve, but would chatter, causing a
disagreeable noise, and damaging the valve.
_To avoid this, the valves of an air compressor are operated by
mechanical means._ Some devices operate the valve directly as soon as
the pressure in the cylinder reaches that of the receiver, while others
simply release it of the spring pressure, the valve itself being lifted
by the air itself. Such devices generally give the valves a full free
opening, without noise.
[Illustration: FIG. 366.]
_The blowing engine_ is almost identical with the air compressor. The
chief difference between them being the ratio of steam cylinder to air
cylinder. While the air compressor furnishes a comparatively small
amount of air at very high pressures, _the blowing engine delivers a
very large volume at lower pressures_.
Blowing engines are mainly used in large blast furnaces, smelting works
and foundries, to furnish the air pressure for cupolas, air furnaces
and smelting ovens.
In Fig. 366 is shown a blowing engine of very large size; the steam
cylinder is 42 inches in diameter, the air cylinder 84 inches, and the
stroke 60 inches.
_The valve gear is of the Reynolds-Corliss type._ The piston rod is
attached to a cross-head extending through the guides, which are
formed by the frame, with wrist pins upon each end, from which the two
connecting rods are suspended with their lower ends connected to the
cranks, as shown in Fig. 366. There are two air piston rods attached to
the main piston and held to the cross-head by nuts at points near the
guides.
The crank shaft carrying the flywheels, which also form the cranks
attached to the ends of this shaft, is located below the steam
cylinder. This construction is of the return connecting rod engine
design, to economize space.
Both the air and steam valve gears are worked from eccentrics on an
auxiliary shaft, driven from the main shaft by bevel gears underneath
the steam cylinder.
_The “Imperial” air compressor_ is presented herewith in Figs. 367 and
368.
The “Imperial” compressor is especially designed for use in machine
shops, foundries and other industrial establishments where it is not
convenient to use a steam driven compressor.
The machine has two vertical, single-acting cylinders, each employing
long trunk pistons that act as guides for the lower ends of the
connecting rods. By this design, the height of the machine is reduced,
stuffing-boxes and crossheads are eliminated, and a minimum number of
bearings required. The cranks are set opposite to each other, so that
when the piston on one side is ascending, the other side is descending.
[Illustration: FIG. 367.]
The machine is made with duplex cylinders for the low pressures used
in sand blast work and the like, and with either duplex or compound
cylinders for higher pressures. In the compound type, an intercooler
is supplied, through which the air passes from the low pressure to the
high pressure cylinder.
_The air cylinders_ are water-jacketed and provided with hooded heads,
so that air may be supplied to them from outside the compressor-room;
the cylinders are cast in one piece with the frame.
[Illustration: FIG. 368.]
_The air-valves_, both inlet and outlet, are of the poppet type, fitted
with light springs, and work vertically. On account of their position
at the bottom of the cylinder, they are well lubricated, and, acting
vertically, they have little tendency to wear out of line with their
seats.
_The air intake passage_ is tapped to receive a supply pipe leading
from out-of-doors, or from some place where cool and clean air is
obtainable. The compressed air is discharged into a passage which is
tapped for a pipe to convey it to the air-receiver.
_All parts of the compressor are easily accessible_ for inspection,
adjustment, or repair. The air-heads may be removed without disturbing
any of the pipe connections. The valves may be taken out by unscrewing
the bonnets.
TABLE
_of parts of the Imperial Compressor_.
=======+=============================
Number |
of Part| Name of Part
-------+----------------------------
1 | Frame
2 | Main-bearing cap
3 | Main-bearing cap-bushing
4 | Fly-wheel
5 | Fly-wheel key
6 | Fly-wheel key set-screw
7 | Crank-shaft
8 | Crank-disc
9 | Crank-disc key
10 | Crank-pin
11 | Crank-pin cap
12 | Crank-pin cap set-screw
13 | Connecting-rod cap
14 | Connecting-rod cap-bushing
15 | Connecting-rod
16 | Piston
17 | Piston-pin
18 | Piston-pin bushing
19 | Piston-pin set-screw
20 | Piston, inside ring
21 | Piston, outside ring
22 | Adjusting-bolt for piston-pin
| end of connecting-rod
23 | Connecting-rod bolt
24 | Guard-plate
25 | Air-head
26 | Air-head gasket
27 | Air-head studs
28 | Inlet valve and stem
29 | Inlet valve-seat
30 | Inlet valve-spring
31 | Inlet valve-stem head
32 | Inlet valve-stem cotter
33 | Inlet valve-bonnet
34 | Outlet valve
35 | Outlet valve-spring
36 | Outlet valve-bonnet
37 | Water inlet pipe
38 | Water outlet pipe
39 | Air inlet pipe
40 | Air outlet pipe
41 | Unloader
42 | Main-bearing grease-cup
43 | Crank-pin grease-cup
44 | Piston-pin grease-cup
45 | Air-cylinder lubricator
46 | Main-bearing studs
47 | Main-bearing liners
48 | Unloader regulating-cylinder
_The Norwalk standard compressor_ is shown in Figs. 361 and 362, the
latter being a longitudinal section; Fig. 361 is a perspective view;
the two compressors are driven by a single steam cylinder having an
adjustable cut-off. The air valves are operated by a positive crank
motion.
_A view of a Pelton water wheel_ operating a compressor it shown in
Fig. 363. The cut represents a compound air compressor in which the
valves are operated mechanically. The water which drives the wheel
enters through the pipe and nozzle secured in the wheel pit, as
represented.
Fig. 364 exhibits a belted duplex air compressor built by
Allis-Chalmers & Co.
Fig. 365 shows a vertical duplex compressor driven by a belt.
[Illustration: FIG. 369.]
All the latter, as may be seen by the engravings, have the positive
valve motion operated by an eccentric. In selecting an air compressor
the following points need consideration: 1, Number of cubic feet of
free air required per minute; 2, Altitude, _i.e._, the number of feet
above the sea level; 3, Steam pressure and air pressure.
_The use of compressed air for operating mining pumps_, while
having advantages in some cases, _is not to be recommended in all_,
particularly on account of the low efficiency of the plant as a whole.
The loss due to leaks is serious, and the long line of piping with its
numerous joints causes much trouble, delay and expense.
_In Fig. 369 is shown a direct acting steam single air compressor_;
simplicity in its construction is a leading feature and there are few
parts in this pump that are liable to wear.
[Illustration: FIGS. 370 AND 371.]
This apparatus is designed for working pressures up to twenty pounds;
it is intended for use in oil refineries, smelting works, blast
furnaces and in all situations where compressed air of medium pressure
is required. They are variously used for sand blasts, ventilating
purposes, and for pneumatic deliveries.
The steam end and valve motion are the regular Deane pattern, assuring
positive operation. The air cylinder is provided with a water jacket.
[Illustration: FIG. 372.]
_A power wall or post air compressor_ is shown in Figs. 370-372. The
machine is single acting and is recommended where little space is
available, as it can be bolted to the wall or to a post, or on the
under side of the ceiling. The crank shaft and connecting rod are of
cast steel. The bearings are babbitted and adjustable. The piston is of
the trunk form, carrying a pin for the connecting rod, and is of extra
length to act as a guide for the lower end of the connecting rod. The
valves are of the poppet type. These compressors are extensively used
in electric power stations for supplying air for removing dust from
electric machinery, in bicycle shops for inflating pneumatic tires,
maintaining a supply of air in pressure tanks, and for various purposes
where a limited supply of air is needed.
These compressors are of _the “Blake” design_ and the following
particulars will be of interest.
TABLE.
------------+-----+-------+-------+-------+-------+-------
Diameter | | | | | |
of |2-1/4| 3 | 4 | 5 | 6 | 7
Cylinder. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Stroke. | 6 | 6 | 6 | 6 | 6 | 6
------------+-----+-------+-------+-------+-------+-------
Revolutions | | | | | |
Per | 150 | 150 | 140 | 140 | 130 | 130
Minute. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Piston Speed| | | | | |
in Feet | 150 | 150 | 140 | 140 | 130 | 130
Per Minute. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Cubic Feet | | | | | |
of Free Air | 2 | 3 | 6 | 9 | 12 | 17
Per Minute. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Working | 150 | 150 | 100 | 100 | 100 | 100
Pressure. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Horse | | | | | |
Power | 5/8 | 3/4 | 1-1/2 | 2 | 2-1/2 | 4
Required. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Pipes.
------------+-----+-------+-------+-------+-------+-------
Suction. | 3/4 | 1 | 1-1/2 | 2 | 2 | 2-1/2
------------+-----+-------+-------+-------+-------+-------
Discharge. | 3/4 | 1 | 1-1/2 | 1-1/2 | 1-1/2 | 1-1/2
------------+-----+-------+-------+-------+-------+-------
Dimensions.
------------+-----+-------+-------+-------+-------+-------
Length. | 22″ | 22″ | 24″ | 30″ | 36″ | 36″
------------+-----+-------+-------+-------+-------+-------
Width. | 13″ | 14″ | 15″ | 16″ | 18″ |19-1/2″
------------+-----+-------+-------+-------+-------+-------
Height. | 32″ |33-1/2″| 38″ |40-1/2″| 43″ | 44″
------------+-----+-------+-------+-------+-------+-------
------------+-----+-------+-------+-------+-------+-------
Diameter | | | | | |
of |2-1/4| 3 | 4 | 5 | 6 | 7
Cylinder. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Stroke. | 6 | 6 | 6 | 6 | 6 | 6
------------+-----+-------+-------+-------+-------+-------
Revolutions | | | | | |
Per | 150 | 150 | 140 | 140 | 130 | 130
Minute. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Piston Speed| | | | | |
in Feet | 150 | 150 | 140 | 140 | 130 | 130
Per Minute. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Cubic Feet | | | | | |
of Free Air | 2 | 3 | 6 | 9 | 12 | 17
Per Minute. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Working | 100 | 100 | 90 | 85 | 60 | 60
Pressure. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Horse | | | | | |
Power | 1/2 | 5/8 | 1-1/4 | 1-3/4 | 2 | 2-1/2
Required. | | | | | |
------------+-----+-------+-------+-------+-------+-------
Pipes.
------------+-----+-------+-------+-------+-------+-------
Suction. | 3/4 | 1 | 1-1/2 | 2 | 2 | 2-1/2
------------+-----+-------+-------+-------+-------+-------
Discharge. | 3/4 | 1 | 1-1/2 | 1-1/2 | 1-1/2 | 1-1/2
------------+-----+-------+-------+-------+-------+-------
Dimensions.
------------+-----+-------+-------+-------+-------+-------
Length. | 16″ | 16″ | 16″ | 24″ | 24″ | 30″
------------+-----+-------+-------+-------+-------+-------
Width. | 13″ | 14″ | 14″ | 14″ | 14″ | 18″
------------+-----+-------+-------+-------+-------+-------
Height. | 28″ |29-1/2″|33-1/2″|37-1/2″|37-1/2″| 42″
------------+-----+-------+-------+-------+-------+-------
_With increase in altitude_ the barometric or atmospheric pressure
falls from 14.7 pounds per square inch at sea level to about 10 pounds
at 10,000 feet above sea level. Since the density of the air decreases
with its pressure it is obvious that at such an altitude the total
weight of air handled by a given displacement is considerably less
than at sea level; and that to fill any volume—a rock drill cylinder,
for instance—with air compressed to 90 pounds, a greater free-air
displacement will be necessary than would be required at sea level. The
relative capacities of a given displacement to do work—as through rock
drills or pumps—at varying altitudes are figured in the following table:
CAPACITIES AT VARYING HEIGHTS ABOVE SEA LEVEL.
==========+=========+==========
Feet above|Barometer| Relative
Sea Level | Inches |Capacities
----------+---------+----------
0 | 30.00 | 1.000
500 | 29.42 | .983
1000 | 28.87 | .967
1500 | 28.33 | .954
2000 | 27.79 | .938
2500 | 27.27 | .924
3000 | 26.76 | .909
3500 | 26.25 | .894
4000 | 25.75 | .879
4500 | 25.26 | .867
5000 | 24.78 | .856
6000 | 23.85 | .827
7000 | 22.95 | .800
8000 | 22.10 | .772
9000 | 21.22 | .750
10000 | 20.43 | .725
12000 | 18.92 | .677
----------+---------+----------
The fact that the heating effect of compressing air from an initial
pressure of 10 pounds absolute to 90 pounds gauge pressure is
theoretically equivalent to that of compression to 132 pounds at sea
level, _makes a two-stage arrangement more imperative in high level
work than under ordinary conditions_.
[Illustration: FIG. 373.]
COMPOUNDING OR TWO-STAGE COMPRESSION.
The two-stage or multi-stage system of air compression is used
generally for high pressure work. The system is most usefully employed
between 40 and 120 pounds gauge pressure. For the moderate working
pressure of 90 to 100 lbs., the two-stage compression has demonstrated
its efficiency chiefly for the reason, that the heat generated in the
last half of the stroke of a single compressor is by the two-stage
process greatly reduced.
Further compounding, for pressures above 100 pounds, becomes quite
necessary to secure the advantages named hereafter; the two-stage has
proved advantageous up to 500 lbs., three-stage up to 1,000 lbs., and
four-stage compression up to 3,000 lbs.
[Illustration: FIG. 374.]
As the pressures increase, however, the machines become more and more
complicated, owing not only to the greater power required, but also to
the heating of the air during compression. The use of water-jackets for
cooling the air in the compression cylinders is general, but this does
not effect thorough cooling, as only a small portion of the air in the
cylinder comes in contact with the jacketed parts. This difficulty has
led to the use of compound machines, in which case inter-coolers are
generally used between the different stages of compression, which cause
the air to shrink in volume between the stages.
Briefly summed up, the chief advantages of multi-stage over
single-stage compression are:
1. _Lower average temperature_, resulting in lower average pressure,
and permitting the compression of the same volume of air with less
expenditure of energy.
2. _Increased safety and ease of lubrication._ When high final
temperatures prevail, part of the lubricating oil vaporizes, and
wear on the piston and cylinder becomes rapid. Under exceptional
circumstances the combination of air and oil vapor may reach the
proportions of an explosive mixture, and if the compression temperature
passes its flash point damage may result. Such accidents are, however,
very rare even in single-stage work; in multi-stage compression, with
proper intercooling, they are impossible.
3. _Greater effective capacity in free air._ The final pressure in the
low pressure cylinder is much lower than in a single-stage machine,
and the air confined in the clearance spaces when expanded down to
atmospheric pressure occupies comparatively little space. Consequently
the inflow of air through the suction valves begins at an earlier point
in the stroke.
4. _The air delivered by a two-stage or multi-stage compressor is dryer
than that furnished by a single cylinder._ Under constant pressure
the power of air to hold watery vapor decreases with its temperature,
and during its passage through the inter-cooler much of the original
moisture in the air is precipitated. Consequently less trouble is
experienced from condensation in the discharge pipe.
A properly designed inter-cooler should reduce the air in the cylinders
to the temperature of the outside air. The economy of compressing in
several stages—or, in other words, compound compressors—is shown from
the fact that in compressing air up to 100 lbs. the heat loss reaches
about 30 per cent. By compressing in two stages, this loss is cut
down to less than half; and in four stages, it is reduced to four or
five per cent. It is evident, therefore, that the higher the pressure
required the more essential is the use of compound machines.
_The inter-cooler_ is the vital feature of the two-stage or multi-stage
machine. In this construction the air is partially compressed in one
cylinder; it is then passed through an inter-cooler where it is cooled
and finally is compressed to the desired degree in the second or other
additional cylinders.
An inter-cooler is shown in Fig. 373. The cooling surface consists of a
nest of small brass water tubes. These tubes break up the stream of air
entering the cooler, while their thin walls insure rapid conduction.
The receiver volume formed by the connecting pipes and inter-cooler
body results in a nearly uniform discharge pressure in the low-pressure
cylinder. The air being outside of the tubes encounters practically no
frictional resistance, and its slow passage allows time for cooling.
A pocket, with gauge glass attached, is so placed as to catch any
precipitated moisture which might otherwise enter the high-pressure
cylinder.
_An after-cooler_ is shown in Fig. 374. This serves to reduce the
temperature of the air after the final compression.
_The heat of compression_, as may be judged from the foregoing,
relating to inter and after-coolers is a feature of interest. The
temperature to which it finally attains depends, 1, upon the initial
temperature; 2, upon the degree of compression, or in other words, _the
amount of work expended_ upon the compression.
The extent of this heating is shown in the following table, _for dry
air_ when compression is performed with no cooling.
Temperature of air before compression, 60° 90°
Temperature of air compressed to 15 lbs. 177° 212°
„ „ „ „ 30 lbs. 255° 294°
„ „ „ „ 45 lbs. 317° 362°
„ „ „ „ 60 lbs. 369° 417°
„ „ „ „ 75 lbs. 416° 465°
„ „ „ „ 90 lbs. 455° 507°
„ „ „ „ 105 lbs. 490° 545°
„ „ „ „ 120 lbs. 524° 580°
_The Norwalk compound compressor_ is shown in outline by the cut 375.
The large air cylinder on the left determines the capacity of the
compressor; for illustration assume its piston at 100 square inches
area; the small air cylinder can have an area of thirty-three and
one-third square inches.
_The small piston only encounters the heaviest pressure_; at 100 pounds
pressure the resistance to its advance is 3,333 pounds. _The resistance
against the large piston is its area multiplied by the pressure which
is caused by forcing the air from the large cylinder into the smaller
cylinder._ In this case it is thirty pounds per square inch. But as
this thirty pounds pressure acts on the back of the small piston, and
hence assists the machine, the net resistance to forcing the air from
the large into the small cylinder _is equal to the difference of the
area of the two pistons multiplied by the thirty pounds pressure_. This
is sixty-six and two-thirds by thirty, and equals 2,000 pounds.
Hence 2,000 pounds, the resistance to forcing the air from the larger
into the smaller cylinder, plus 3,333 pounds, the resistance in the
smaller cylinder to compressing it to 100 pounds, is the sum of all the
resistances in the compound cylinders at the time of greatest effort.
This is 5,333 pounds. By thus reducing the work to be done at the end
of the stroke, more work is done in the first part, and the resistance
is made nearly uniform for the whole stroke.
[Illustration: FIG. 375.]
NOTE.—Arrows on the water pipes show the direction of the water
circulation. When the pistons move as indicated by the arrow on the
piston rod, steam and air circulate in the direction shown by arrows
in the cylinders.
A—Inlet Conduit for Cold Air.
B—Removable Hoods of Wood.
C—Inlet Valve.
D—Intake Cylinder.
E—Discharge Valve.
F—Inter-cooler.
G—Compressing Cylinder.
H—Discharge Air Pipe.
J—Steam Cylinder.
K—Steam Pipe.
L—Exhaust Steam Pipe.
N—Swivel Connection for Crosshead.
O—Air Relief Valve, to effect easy starting after stopping with all
pressure on pipes.
1—Cold Water pipe to Cooling Jacket.
2 and 3—Water Pipes.
4—Water Overflow or discharge.
5—Stone on end of Foundation.
6—Foundation.
7—Space to get at Underside of Cylinder.
8—Floor Line.
THE AIR LIFT PUMP.
The Air Lift is one of the simplest methods of raising water from
underground sources. The main principle of its operation may be stated
thus: _air under pressure is conveyed into the lower end of the water
pipe through a suitable foot piece_.
[Illustration: FIG. 376.]
[Illustration: FIG. 377.]
City and town water works, asylums and hospitals, plantations, railway
water tanks, irrigation, private country houses, pumping mines, ice
manufactories, breweries, cold storage and packing houses, textile
mills, dye works, bleacheries, sewerage installations, dry docks,
seaside water works, stock farms; in fact, everywhere that clear and
abundant water is needed are opportunities for the application of the
Air Lift System of pumping water.
Nor is it alone for securing public water supplies that the Air Lift
is of special value. Within recent years the question of an abundant
and pure water supply for manufacturing, irrigation and other uses
has become one of equal importance. After an extensive experience,
two general systems have been devised for utilizing the water which
lies immediately below the surface of the ground. One, known as the
Deep-well Pump System, for which a working pump is used, and the other
the Air Lift System, which employs compressed air to raise the water,
either by means of its inherent expansive force or the difference in
specific gravity between compressed air and water.
NOTE.—Dr. Julius J. Pohle is admitted to be the original inventor
of this admirable and useful device. At first all systems by which
water or liquids were lifted by compressed air were more or less
extravagant, but with large experience and with improvements in air
compressor economy, the Air Lift has made valuable strides. Dr. Pohle
was actively associated with the Ingersoll Sargeant Co. until his
death, 1896, since which time his system has been further improved
and developed by a wider application and broader experience.
_Theory of the Air Lift._ Opinions differ as to the true theory of the
Air Lift. A common Air Lift case is one where there is a driven well in
which the water has risen approximately near the surface. In this well
is placed a large pipe for the discharge of the water, which is known
as an “_eduction pipe_.”
[Illustration: FIG. 378.]
This pipe does not touch the bottom of the well, but is elevated
above it so as to freely admit the water through its lower open end.
Alongside of this pipe, either on the outside or within, is a small
pipe properly proportioned and intended to convey compressed air to a
point near the bottom of the eduction pipe. It is usual to provide a
“foot-piece,” see Fig. 378, which forms a nozzle connecting the air
pipe with the water pipe, but in what is known as the “central pipe
system” this foot-piece is not used, the air pipe being placed within
the eduction-pipe to a point near the bottom, where it discharges the
compressed air into the water column.
Many neighborhoods are dependent upon well water, and there are few
districts where an ample supply is not to be secured from wells
properly made; this water is generally pure and wholesome. It is also
of uniform temperature the year round—cool and pleasant in the summer,
because the underground pipe and earth temperature remain uniformly
low. In winter, well water being warmer than that taken from ponds
and rivers, is not so apt to freeze, and, from all considerations of
temperature and purity, well water is greatly to be preferred. Many
cities located on rivers having a gravel bed formation find that, by
placing wells of suitable construction far enough back from the bank,
there is a natural filter bed, leaving the water clear, even when the
river itself is muddy. When river or other surface water is good the
wells may be sunk close to the edge, the water flowing down from the
top of the wells.
There are not many underground formations where wells should be
located close together. Such wells may affect or rob each other,
and it is usually best to spread them out on a line across what is
known to be the underground flow. Some finely creviced or tight rock
formations have a strong head with but little capacity, and wells in
such formations, if pumped hard, yield but little additional water.
They should be scattered and pumped moderately, maintaining a low and
economical lift. In other cases, one well in a group will give as much
water as all together, and more territory must be drawn on.
[Illustration: FIGS. 379-382.]
_The Pohle system of elevating liquids_ is shown in Fig. 377.
The process “consists in submerging a portion of an open-ended
eduction-pipe in a body of the liquid to be raised and continuously
introducing into the liquid within the lower part of the pipe a series
of bubbles of compressed gaseous fluid containing enough of the fluid
to expand immediately across the pipe and fill the same from side to
side, forming pipe-fitting piston-like layers at or just above the
point of their entrance into the pipe, whereby the column of liquid
rising in the pipe after the forcing out of the liquid first standing
in the latter is subdivided by the gaseous fluid into small portions
before it reaches the level of the liquid outside of the pipe, and a
continuously upward-flowing series of well-defined alternate layers of
gaseous fluid and short layers of liquid is formed and forced up the
pipe.”
The figures represent the apparatus in a state of action pumping
water, the shaded sections within the eduction-pipe, W, representing
water-layers and the intervening blank spaces air-layers.
At and before the beginning of pumping, the level of the water is
the same outside and inside of the discharge-pipe, W,—incidentally,
also, in the air pipe. Hence the vertical pressures per square
inch are equal at the submerged end of the discharge pipe. When,
therefore, compressed air is admitted into the air pipe, _a_, it must
first expel the incidental standing water before air can enter the
eduction-pipe, W. When this has been accomplished, the air-pressure
is maintained until the water within the eduction-pipe has been
forced out, which it will be in one unbroken column, free from
air-bubbles.
When this has occurred the pressure of the air is lowered or its bulk
diminished and adjusted to a pressure just sufficient to overcome
the external water-pressure. It is thus adjusted for the performance
of regular and uniform work, which will ensue with the inflowing air
and water, which adjust themselves automatically in alternate layers
or sections of definite lengths and weights. It will be seen in the
figures that the lengths of the water-columns (shaded) and air (blank
spaces) 1 and 1 are entered at the right of the discharge-pipe,
W; also, that under the pressure of two layers of water 1 and 2,
the length of the air column 2 is 6.71 feet long, and so on. The
lengths of aggregate water columns and the air columns which they
respectively compress are also entered on the right of the water-pipe.
On the left of the water-pipe are entered the pressures per square
inch of these water columns or layers. Thus the pressure per square
inch of column 1 is seen to be 1.74 pounds; that of 2, consisting of
two columns or layers 1 and 2 each 4.02 feet long, to be 3.49 pounds,
and that of 10, consisting of nine columns or layers of water 1 to 9,
inclusive, each 4.02 feet long, and one of 3.80 feet in length (viz.,
layer 10) to be 17.35 pounds, and the aggregate length of the layers
of water is 39.98 feet in a total length of ninety-one feet of pipe.
It will be noted that the length of pipe below the surface of the
water in the well is 55.5 feet, and that the difference between
this and the aggregate length of the water layers (39.98) is 15.52
feet—that is, on equal areas the pressure outside of the pipe is
greater than the pressure on the inside by the weight due this
difference of level, which is 47.65 pounds for the end of the
discharge pipe.
It is this difference of 15.52 feet, acting as a head that supplies
the water pipe, which puts the contents of the pipe in motion, and
overcomes the resistance in the pipe. In general the water layers are
equal each to each, and the pressure upon any layer of air is due to
the number of water layers above it.
Thus the pressure upon the bottom layer of air 10 in the figure is
due to all the layers of water in the pipe (17.35 pounds), and the
pressure upon the uppermost layer of air 1 is due to the single
layer of water, 1, at the moment of its discharges beginning—viz.,
1.74 pounds per square inch. As this discharge progresses this is
lessened, until at the completion of the discharge of the water layer
the air layer is of the same tension as the normal atmosphere.
_The air pipe_ is connected with an air receiver on the surface, which
is at or near the engine room, in which there is _an air compressor_.
This air pipe is provided with a valve on the surface. Before turning
on the air the conditions in the well show water at the same level on
the outside and inside of the eduction-pipe. At the first operation
there must be sufficient air pressure to discharge the column of water
which stands in the eduction-pipe.
This goes out _en masse_, after which the pump assumes a normal
condition, the air pressure being lowered and standing at such a
point as corresponds with the normal conditions in the well. This
is determined by the volume of water which the well will yield in a
certain time and the elevation to which the water is discharged.
NOTE.—This extended description of the principles upon which an air
lift operates—with its illustrations—is drawn almost word for word
from the original patent claims of Dr. Pohle. The occupation of
the space in the work is justified by the increasing importance of
this system of water supply and its practical applications in the
industrial world.
Year by year the world’s visible supply of coal—so long stored and
hidden away in the earth’s crust awaiting the advent of man—is
diminishing, next will dawn the age of air and water with electric
transmission.
After the standing water column has been thrown off by the pressure
the air rises through the water reduces its weight, with the result
that the water is expelled as fast as the well supplies it, _the water
outside the pipe, acting as a head, flows into the discharge pipe by
the force of gravity_.
The machinery necessary for a system of pumping comprises, 1, _an air
compressor_; 2, a receiver to store and equalize the pressure; 3, the
head piece and foot piece for the well; and, 4, the necessary piping
for the air supply and water discharge.
[Illustration: FIG. 383.]
With an available supply of air under pressure _the pump proper
consists of simply a water discharge and air pipe_, the latter arranged
and properly controlled to inject air into the former at the point of
proper submersion. It is readily seen that the apparatus is so simple
that as a pump it cannot get out of order; in cases, where mud, sand or
gritty material is encountered, it will handle such matter _with the
water_ and without injury to the system, as nothing comes in contact
with the moving parts.
[Illustration: FIGS. 384, 385.]
Absence of all obstructing mechanism in the wells allows each to be
operated to its full capacity. Production, therefore, does not depend
upon the pump, but rather upon the capacity of the well to yield water;
the natural yield of wells is often increased by this process of using
compressed air admitted close to the bottom of the discharge pipe, the
water is set in motion at a considerable depth, and by this action the
well is “cleaned.”
_Purification is effected by aeration during the process of pumping_,
the absorption of air by the water preventing the formation of
unsanitary growths.
_Three styles of well heads_ are shown in Figs. 383, 384 and 385.
_The deflector head_, Fig. 383, is attached to the well casing or
discharge pipe by standards. This form of head piece is generally used
where the water is to be raised to the surface, or just below the
surface into a tank, where the air is allowed to separate itself, and
the water flows to some central collecting reservoir, where it is used
or forced by means of an ordinary pump to a higher elevation. The head
piece offers no obstruction to the discharged water.
_The offset discharge_, Fig. 384, is adapted to situations where the
water is to be pumped by air direct from the well to some elevation
above the well.
_The elbow discharge_, Fig. 385, shows the common form of well head
known as the elbow head, adapted to be used either as a cap for the
well casing itself, or used in connection with a suitable discharge
pipe.
_The foot piece, or nozzle_, which regulates the admission of air to
the discharge pipe at the point where the air comes in contact with the
water, thereby makes it possible to carry air at full pressure to the
end of the air pipe, and utilizes the energy due to the velocity of the
discharged air.
_After a well is once regulated or balanced_ there is but little
occasion to move the adjusting wheel or valve, the starting and
stopping of the flow of any particular well being accomplished by means
of an ordinary valve or plug cock on the air pipe at or adjacent to the
well.
_One Central Station of suitable capacity will operate several wells
no matter how far apart._ The necessity of maintaining a number of
separate pumping plants is thus done away with, and in taking a supply
of water from an underground source the wells can be located without
reference to the power plant, and at such distances apart as will best
maintain the highest average pumping level.
Although the principle of the action governing all pumps of this
description is so simple, there are a number of factors having a direct
influence upon the performance of the pump, which have been expressed
in the following terms by a well-known expert:
(_a_) Depth of submersion of point of air discharge below still water
surface.
(_b_) Velocity of water at point of air discharge.
(_a_) and (_b_) determine the necessary air pressure. If (_a_) is
constant, the pressure decreases when (_b_) increases.
(_c_) Area of main, or water discharge pipe.
(_d_) Net lift to point of water discharge, including velocity head
at that point.
(_e_) Volume of air (at atmospheric pressure) discharged per unit of
time.
(_f_) Ratio of expansion of air as it rises through the main pipe;
(_f_) may be considerably modified by the temperature of the water.
(_g_) Total volume of air in main pipe at any instant. This
determines the specific gravity of the discharging column.
(_h_) The volume of each individual bubble within the main.
Letters are for reference only and do not indicate the order of
importance nor of effect.
It was at first supposed that in all Air Lift cases the water was
discharged because of the aeration of the water in the eduction-pipe,
due to the intimate co-mingling of air and water. Bubbles of air rising
in a water column not only have a tendency to carry particles of water
with the air, but the column is made lighter, and, with a submergence
or weight of water on the outside of the eduction-pipe, there would
naturally be a constant discharge of air and water. This is known as
the Frizell System, and where the lifts are moderate—that is, where the
water in the well reaches a point near the surface—it is very likely
that the discharge is due to simple aeration.
Most air lift propositions are deep-well cases—that is, the water is
lifted a distance greater than 25 feet; and just in proportion as the
lift is increased do we get away from the aerated form idea, and so
when the air pressure is greater than the head of water, a certain
volume of compressed air is received into the eduction-pipe, the water
in this pipe is at that time moving rapidly upward; that is, its
momentum has been established. Hence the air takes up this velocity and
goes upward with the water from the energy received from the elasticity
of the air due to its compressor.
A practical example of the successful working of an air compressor for
raising water from a driven well 319 feet is described and illustrated
by the _Practical Engineer_ as shown in the sketch, Fig. 386.
[Illustration: FIG. 386.]
The air compressor forces the air down the inside pipe, which is 1-1/4″
in diameter. The outside pipe, which is 3″ in diameter, has its lower
end submerged in the well. The compressed air forces a rising column of
air mingled with water in the outer pipe to the supply tanks, which are
situated at the top of the building.
_Direct Air Pressure Pumps._ This term is applied to that class of
pumps in which the liquid is taken into an air tight vessel and then
driven out through pipes to a higher level by the application of
compressed air directly on the surface of the liquid in the tank, thus
dispensing with cylinders, pistons, valves, glands, etc., of the more
common class of pumps.
[Illustration: FIG. 387.]
Fig. 387 shows the parts of the pump; its operation is as follows:
Suppose the compressor to be in operation and the switch set as in the
figure; the air will be drawn out of the right tank and forced into the
left tank, and in so doing will draw water into the former and force it
out of the latter. The charge of air in the system is so adjusted that
when one tank is emptied the other is filled, and at that moment the
switch will be automatically thrown, reversing the pipe connections and
thereby reversing the action in the tanks.
_The switch_ is a simple mechanism placed on the air pipes near the
compressor. It can be automatically operated in one of three ways:
_First_, by means of the suction which occurs in the intake pipe to
the compressor, when water is drawn above its outside level in one of
the tanks. The details of the mechanism to utilize this suction are
very simple.
_Second_, by a mechanism, that will throw the switch at some assigned
number of strokes of the compressor, the proper number being that
which will empty one tank and fill the other. This can be closely
computed beforehand and can be determined exactly by test when
commencing operation and the switch adjusted accordingly.
_Third_, by an electrically controlled mechanism, the circuit being
made and broken by a pressure gauge on the intake of the compressor.
The Pneumatic Engineering Co. are the makers of this apparatus, named
_the Harris System_ of raising water by direct pressure.
THE STEAM
FIRE ENGINE
[Illustration: FIG. 388.]
THE STEAM FIRE ENGINE.
The steam fire engine is practically a portable pumping engine.
_It is in all respects a complete water works on a small scale_,
hence, a modern apparatus must, within itself, and each part working
harmoniously with every other part, contain several complex mechanisms.
This will readily appear by a study of the several succeeding
illustrations; the first, which in the figure below exhibits a “view”
of a complete machine.
[Illustration: FIG. 389.
(See page 109.)]
Modern steam fire engines are classified as to “size,” as “double extra
first,” etc.; their capacities and weights are given approximately in
the following
TABLE.
===================+========================+===============
SIZE OF ENGINES. | CAPACITY. | WEIGHT.
-------------------+------------------------+---------------
Double Extra First | 1,300 gallons per min. | 10,800 pounds.
Extra First | 1,100 gallons per min. | 9,800 pounds.
First | 900 gallons per min. | 8,800 pounds.
Second | 700 gallons per min. | 7,800 pounds.
Third | 600 gallons per min. | 6,800 pounds.
Fourth | 500 gallons per min. | 5,800 pounds.
Fifth | 400 gallons per min. | 4,800 pounds.
-------------------+------------------------+---------------
The foregoing list of the sizes, capacities, etc., of the fire
apparatus now in general use, affords a very good comparison between it
and that which has, little by little, progressed for two thousand years
to its present high plane. _The application of electric power to the
operation of the pumps_ and the propulsion of the apparatus is yet in
too elementary a stage for present discussion in a work of this scope
for—
It is essential that the machinery relied upon for fire protection
should at all times be ready for instantaneous and effective service;
this, because both life and vast property interests are at stake,
_hence of all machines made, the modern steam fire engine is produced
with a niceness of finish and accuracy of fit equaled by no other_,
when size is considered; it approaches towards the perfection seen in
the mechanism of a fine watch.
[Illustration: FIGS. 390, 391.]
This degree of excellence has been arrived at by successive steps. The
illustration on page 92, Fig. 388 exhibits the fire-fighting tools of
the early Romans and similar apparatus was used in England as late as
the fifteenth century. The implements shown are a syringe, a sledge
hammer, two fire hooks and three leathern buckets conveniently arranged
against a wall. _The owners of houses or chimneys that took fire were
fined_; and men were appointed to watch for fires and give the alarm.
In 1472 a night bellman was employed in Exeter to alarm the inhabitants
in case of fire, and in 1558, leathern buckets, ladders and crooks,
were ordered to be provided for the same city; no application of the
pump seems to have been then thought of.
Syringes continued to be used in London till the latter part of the
17th century, when they were superseded by more improved machines.
They were usually made of brass and held from two to four quarts. The
smaller ones were about two feet and a half long, and an inch and a
half in diameter; the bore of the nozzles being half an inch. _Three
men_ were required to work each, which they achieved in this manner:
one man on each side, grasped the cylinder with one hand and the nozzle
with the other; while the third man worked the piston! Those who held
the instrument plunged the nozzle into a vessel of water, the operator
then drew back the piston and thus charged the cylinder, and when it
was raised by the bearers into the required position, he pushed in the
piston and forced, or rather endeavored to force, the contents upon the
fire.[A]
[A] NOTE.—We are told that some of these syringes are preserved in one
or two of the parish churches. It can excite no surprise that London
should have been almost wholly destroyed in the great fire of 1666,
when such were the machines upon which the inhabitants chiefly depended
for protecting their property and dwellings. If the diminutive size of
these instruments be considered, the number of hands required to work
each, beside others to carry water and vessels for them, the difficulty
and often impossibility of approaching sufficiently near so as to
reach the flames with the jet, the loss of part of the stream at the
beginning and end of each stroke of the piston, and the trifling effect
produced—the whole act of using them, appears rather as a farce. These
primitive devices were known as “hand squirts.”
[Illustration: FIG. 392.]
Figs. 390 and 391 show an early form of syringe. A description of it
translated from the original Greek, written by Hero of the ancient city
of Alexandria, reads thus—“A hollow tube of some length is made, A,
B; into this another tube, C, D, is nicely fitted, to the extremity
of which is fastened a small plate or piston; at, D, is a handle, E,
F. Cover the orifice, A, of the tube, A, B, with a plate in which an
extremely fine tube, G, H, is fixed, its bore communicating with A, B,
through the plate—as a vacuum is thus produced in A, B, something else
must enter to fill it, and as there is no other passage but through the
mouth of the small tube we shall of necessity draw up through this any
fluid that may be near.”
Fig. 392 is a copy of an old engraving (A.D. 1568) which shows an
“engine” of this type sufficiently enlarged to contain a barrel or more
of water and as a matter of necessity, placed on a carriage.
[Illustration: FIG. 393.]
To eject the water uniformly, the inventor moved the piston by a screw;
and when the cylinder was emptied, it was refilled through the funnel
by an attendant, as the piston was drawn back by reversing the motion
of the crank. When recharged, the stop cock in the pipe of the funnel
was closed and the liquid forced out as before. As flexible pipes of
leather, the “ball and socket” and “goose-neck” joints had not been
introduced, some mode of _changing the direction of the jet_ of this
enormous syringe was necessary. To effect this, it is represented
as suspended on pivots, fastened in two upright posts: to these are
secured (see figure) two semi-circular straps of iron, whose centers
coincide with the axis, or pivots, on which the syringe is balanced. A
number of holes are made in each, and are so arranged as to be opposite
each other. A bolt is passed through two of these, and also through a
similar hole, in a piece of metal, that is firmly secured to the upper
part of the open end of the cylinder; and thus holds the latter in any
required position. The iron frame to which the box or female part of
the screw is attached, is made fast to the cylinder; and it is through
a projecting piece on the end of this frame that the bolt is passed.
By these means, any elevation could be given to the nozzle, and the
syringe could be secured by passing the bolt through the piece just
mentioned, and through the corresponding holes in the straps. When a
_lateral_ change in the jet was required, the whole machine was moved
by a man at the end of the pole, as in the figure. Jointed feet were
attached to the frame which were let down when the engine was at work.
Fig. 393 shows an engine for extinguishing fires, which has come down
to us from the times of Hero, who thus describes it:
NOTE.—The siphons used in conflagrations are made as follows. Take
two vessels of bronze, A B C D, E F G H (Fig. 393), having the
inner surface bored in a lathe to fit a piston (like the barrels of
water-organs), K L, M N, being the pistons fitted to the boxes. Let
the cylinders communicate with each other by means of the tube, X O
D F, and be provided with valves, P, R, such as have been explained
above, within the tube, X O D F, and opening outwards from the
cylinders. In the bases of the cylinders pierce circular apertures,
S, T, covered with polished hemispherical cups, V Q, W Y, through
which insert spindles soldered to, or in some way connected with,
the bases of the cylinders, and provided with shoulders at the
extremities that the cups may not be forced off the spindles. To the
center of the pistons fasten the vertical rods, S E, S E, and attach
to these the beam A´ A´, working, at its center, about the stationary
pin, D, and about the pins, B, C, at the rods, S E, S E. Let the
vertical tube, S´ E´, communicate with the tube, X O D F, branching
into two arms at, S´, and provided with small pipes through which to
force up water, such as were explained above in the description of
the machine for producing a water-jet by means of the compressed air.
Now, if the cylinders, provided with these additions be plunged into
a vessel containing water, I J U Z, and the beam, A´ A´, be made
to work at its extremities, A´, A´, which move alternately about
the pin, D, the pistons, as they descend, will drive out the water
through the tube, E´ S, and the revolving mouth, M´. For when the
piston, M N, ascends it opens the aperture, T, as the cup, W Y,
rises, and shuts the valve, R; but when it descends it shuts, T, and
opens, R, through which the water is driven and forced upwards. The
action of the other piston, K L, is the same. Now the small pipe, M´,
which waves backward and forward, ejects the water to the required
height but not in the required direction, unless the whole machine be
turned round; which on urgent occasions is a tedious and difficult
process. In order therefore, that the water may be ejected to the
spot required, let the tube, E´ S´, consist of two tubes, fitting
closely together lengthwise, of which one must be attached to the
tube, X O D F, and the other to the part from which the arms branch
off at, S´; and thus, if the upper tube be turned round, by the
inclination of the mouthpiece, M´, the stream of water can be forced
to any spot we please. The upper joint of the double tube must be
secured to the lower to prevent its being forced from the machine by
the violence of the water. This may be effected by holdfasts in the
shape of the letter L, soldered to the upper tube, and sliding on a
ring which encircles the lower.
[Illustration:
FIG. 394.
(See page 109.)
]
Heron or Hero was an Alexandrian mathematician of the 3d Century B. C.
He was the inventor of “Hero’s Fountain” in which a jet of water was
maintained by condensed air and of a machine acting upon the principle
of Barker’s Mill, in which the motion was produced by steam. _Fragments
of his works on mechanics have been preserved_ for more than 2000 years.
Lack of space forbids following, as could be done, the growth of the
modern steam fire engine from these primitive beginnings to its present
high point of excellence and widely extended use. Wherever civilized
men are gathered into towns and cities there can be found this
admirable mechanism affording protection to both life and property.
The Working Parts,
The Boiler, and
Its facilities for Transportation are the three essential parts of
the one mechanism which combined, form the steam fire engine. In
brief reference to the last qualification, it may be said that these
engines are drawn by hand, by one or more horses, or other animals and
_are self-propelled by both steam and electric power_; again the hose
carriage can be drawn by hand, by horses or can be attached to the
engine.
_The main working parts of the machine_ can be easily divided into two
parts, _the engine_ and _the pump_.
The boiler in all its details has been designed to meet the
requirements peculiar to the fire service and needs a full explanation
with illustrations.
_The auxiliary appliances_ found necessary for the operation of the
modern steam fire engine are large in number; this is owing to the
fact that the machine combines within itself so complete a system for
extinguishing fires. _The supplies_ needed for its maintenance and use
are also in proportion, as to quantity and variety, to its complex make
up.
_The boiler_, which is generally of the upright semi-water tube type,
is combined with the engine by means of a strong iron frame, which
carries all the appliances as well as the driver’s seat, and also forms
the body of the truck.
[Illustration: VERTICAL SECTION.
FIG. 395.]
_The pumps_ may be of the reciprocating or rotary type, and are
generally placed in front of the boiler. If of the reciprocating type,
two pumps are placed alongside each other, and are operated either by a
double slide valve or piston valve engine.
_The piston rods_ connect directly with the plunger rods and are
also connected to a crank shaft by means of either connecting rods
or yokes, the cranks being set at right angles, so that one pump is
always acting, while the other passes the dead center, thus giving a
practically steady stream.
_The engine exhausts into the stack_, which gives the necessary draft.
Some engines are equipped with a boiler feed pump, others only depend
upon an injector, or feed directly from the main pump. _The coal box_,
which also forms a platform for the engineer to stand upon while under
way, is placed back of the boiler.
_All engines are equipped with two suctions and two discharge
openings_, so that either side may be connected up. The tool box and
driver’s seat are in front of the engine. The frame rests upon springs,
to make the machine easy running.
[Illustration: FIG. 396.]
_The Fox Boiler_ with which the Metropolitan and other engines are
equipped deserves an extended notice. It is shown in vertical section
in Fig. 395, the arrows indicating the steam and water circulation.
Its design, while simple, embodies some original ideas as to the
arrangement of the tube surface method of circulation, etc.; it is
a steam generator of _the water tube type_ designed to meet the
requirements peculiar to the fire service. The steam take-off and
sectional view of shell with the tube system removed is shown in Fig.
397.
NOTE.—Working pressure can be generated in this boiler in six minutes
from cold water, and the provisions for expansion are so near perfect
that no bad effect is noticeable from such severe treatment. The
manifold tube sections are tested to 600 pounds pressure, and are put
together with great care; _the manifolds are counter-bored_ to admit
the full diameter of the tube, leaving none of the threaded portion
exposed.
[Illustration: Plan showing Steam Take-Off.—FIG. 397.]
[Illustration: Top View of Empty Shell, showing manifold Beam.—FIG.
398.]
The boiler consists primarily of a simple annular shell heavily
stay-bolted throughout, and constitutes a water-legged fire-box and
steam reservoir; the principal heating surface of the boiler consists
of straight water tubes, manifolded in sectional form and housed within
the shell, the general scheme providing arrangements to make all
connections readily accessible, and permitting the withdrawal from the
boiler of any one or all of the several tube sections; the shell, being
practically a permanent feature, need seldom be disturbed by reason of
subsequent repairs or renewals of the tube systems.
It may be noted that the lower part, or water leg, of the shell is
contracted for the purpose of facilitating the rapid generation of
steam, and also providing the maximum grate area; at a point somewhat
below the water line of the boiler, the inner shell is flanged inward,
thereby enlarging the annular space between the inner and outer sheets
for the purpose of providing a more copious reservoir.
The water line being carried in this larger part of the shell, tends
to prevent the rapid fluctuation of the water level, and the increased
area of its surface at this point is favorable to the disengagement of
the steam.
[Illustration: Sectional Unit for Outer-Tube System.
FIG. 399.]
[Illustration: Sectional Unit for Inner-Tube System.
FIG. 400.]
When held at its normal point, the water line protects the flanged part
of the inner shell; but no damage can occur, either from a willful or
an accidental drawing down of the water, as the spray deflected through
the nipples of the outer tubes is sufficient to protect the flange,
although the actual water level is well down in the leg.
The steam in contact with the upper part of the shell is by no means
dry, and the heat absorbed at this point is amply sufficient to
protect it. To insure a delivery of dry steam to the cylinders, a
peculiar _“take-off” ring_ is provided at the highest part of the
steam reservoir, the same encircling the inside sheet of the shell.
The upper edge of the ring is perforated at a distant point from the
throttle, and the steam entering the ring chamber in small streams is
held in close contact with the hot shell at a point closely adjacent
to the upper line of rivets; the steam by this means is dried during
its passage to the throttle, and the heat thus absorbed serves as a
protection to the rivets just referred to.
NOTE.—The life of both water tubes and fire tubes is generally found
disproportionate to the heavier parts used in boiler construction,
and experience shows conclusively that the cost of subsequent
maintenance is measured directly by, and may be diminished by, the
facility with which these indispensable parts may be replaced or
repaired in an emergency.
The principal heating surface of the boiler is contained in the
vertical water tube sections, which comprise and will be referred to,
as _an inner and an outer tube system_.
_The outer system_, embraces the short manifold sections which
completely encircle the fire-box walls. The top end of each section
is screwed and suspended from the flanged part of the shell, and the
lower end is stayed by direct connection with the leg of the fire-box.
_The tubes are “staggered”_ in their manifolds, thereby exposing the
greatest possible surface to the fire, and filling out the space due
to the difference in the width of the water-leg and steam space of the
shell.
The direct application of heat to the tubes causes a natural and active
upward current therein, which in turn induces a corresponding downward
movement of the water in the leg of the fire-box, and promotes the flow
into the feed pipes.
_The inner-tube system_ comprises those tube sections which extend to
the upper limits of the boiler, their number and arrangement being
such as to completely fill the interior of the shell above the space
required for the combustion of the fuel. The construction of the
vertical inner-tube system is simple, and consists of the required
number of manifold sections, suitably arranged to conform to the
circular space occupied, the flat inner end of each upper manifold
being rigidly bolted to a heavy transverse beam, which in turn is
supported in suitable pockets secured to the upper part of the shell.
At the top of the boiler, each section has its own connection with
the steam space, and it is easy to remove either one of the sections
separately without disturbing the others; _or the entire inner-tube
system can be raised out of the boiler as a whole, after breaking the
proper connections_, all of which are accessible. The current of steam
and water carried over through the top connections of the inner system
is generally sufficient to keep the tubes clear of scale; and the
point of discharge and disengagement is brought down low, to prevent
its mixture with the drier steam contained in the highest part of the
shell.
When connected to a stationary boiler, as is now the general practice
in fire departments, the circulative currents of water reach all
parts of the boiler, hence its contents may be kept uniformly at any
desirable temperature.
_A stationary heater for the fire engine_ consists of a small boiler,
placed at some convenient point near the same when in quarters. It
is connected with the engine boiler by means of suitable circulating
pipes, the entire arrangement being adapted to supply hot water through
pipe connections which separate automatically as the engine leaves the
house.
[Illustration: Top View.—FIG. 401.]
Although the best types of fire engine boilers require but a few
minutes’ time to generate a working pressure from cold water, the
general adoption of many improvements has made the stationary heater an
essential part of a complete equipment.
[Illustration: Bottom View.—FIG. 402.]
Experience proves that the life of the boiler is prolonged by being
kept constantly in a state of activity, and the elevated temperature of
the water insures prompt and efficient work by the steamer at the very
time when a few moments’ delay may breed disaster.
_The pumps_ fitted and adapted to steam fire engines comprise two
separate and distinct double acting piston pumps united in a single
body and akin in many details to the duplex pump.
[Illustration: FIG. 403.]
Calling in mind the well-known fact, that, in drawing a water supply
the only power available to bring the fluid under forcing influence of
the pump’s pistons is the limited pressure of the atmosphere, therefore
the importance of all details concerned in first inducing an entry of
the water will be readily conceded. Easy and unrestricted “suction
ways” in direct communication with properly proportioned receiving
valves (and these valves suitably arranged in close proximity to the
working barrels of the pump), are the conditions that must always
remain paramount, and to which all other features must give way, to
safely attain the desirable high piston speeds. The value of perfect,
simple and direct water ways, the passages, and all which they imply,
has been studied in the design of this pumping engine. See Figs.
403-407.
The facilities provided for exposing the interior mechanism permits
all such parts to be quickly reached for examination, or detached for
renewal or repair, and this can be done without dismounting the entire
pumps or greatly disturbing their exterior attachments. It will be
seen, by reference to the cuts, that all of the valves can be easily
and quickly examined, and also replaced, by removing the caps that
enclose the chambers; all joints required for this purpose are made
between flat surfaces planed true, as shown in Fig. 404; gun metal, or
other suitable composition, is used and no part of the pump body is
subject to wear, either by friction or corrosion. _All valve seats are
screwed into place_, and either these or the working barrels of the
pump may be readily replaced with new ones, in case the same should
become worn. All stud bolts, nuts, etc., coming in contact with water,
are made of drawn phosphor or Tobin bronze; nipples, piping, etc., are
of brass.
[Illustration: FIGS. 404, 405, 406 and 407.]
Suction or hydrant connection may be made at either side of the engine;
and, in operation, the central core of the pump body is _practically
a continuation of the suction hose_, and serves to establish a direct
communication with the receiving pump valves, arranged on opposite
sides of the chamber. This chamber, as shown in the sectional view,
Fig. 408, thus _becomes the distributing center, from which the
incoming water flows to the suction valves_. The current from the
suction is not required to change its general direction, and but little
friction is encountered by the water in its diversion through the pump
valves.
The position of the suction or receiving valves, in relation to the
water cylinders, may be understood by reference to Fig. 408, which
shows the same arranged in a cluster around the open ends of the
barrels. The suction valve area is large, and the proportions adopted
contribute largely to the smooth running of the pump, under conditions
of speed seldom attempted in ordinary practice.
[Illustration: FIG. 408.]
The valves in this pump are controlled by improved springs, the
tension of which is at all times the same; and which are made of
phosphor bronze; _the force chambers_ in opposite ends of the pumps are
practically equal, and, owing to the close proximity of the valves, the
clearance is reduced to a minimum The discharging outlets are elevated
above the highest point of the valve chambers, and the communicating
passages are designed to prevent conflicting currents, and also to
permit the pump to free itself promptly of air. The pistons are of a
frictionless type, and in accordance with the usual practice of working
double pumps in unison, the cranks controlling the movements of the
pistons are placed at 90 degrees.
[Illustration: FIG. 409.]
A convenient and effective arrangement of suction strainers is shown
in Fig. 409. Perforated cages are introduced into the suction chambers
through the inlets on opposite sides of the pump. The ends of these
cages are open, and a short sleeve, which is permanently secured within
the pump, serves to support and also to establish communication from
one cage to the other.
The surface of both cages is, therefore, available as a strainer, and
any obstruction entering with the water is carried to the opposite
side, to a point where it can be removed, without first detaching the
suction hose.
The driving mechanism supplied with the American Pump is shown by Figs.
389 and 394, which are perspective views engraved from photographs. It
may be noted that the design is practically compact and well balanced,
and embodies many excellent advantages found in no other type of fire
engine.
_The pumps, steam cylinders and driving parts_ are built as a unit,
and have no direct connection with the boiler other than the necessary
stays and pipe connections, all of which are readily accessible and
visible for inspection at any time.
The steam cylinders used in connection with the pumps are of the
ordinary slide valve type. The valve chests are easily opened from
either side of the engine for examination, and the valve rods are made
from a special composition and can not corrode. The valve motion is
simple, and there is nothing connected with the steam ends that may not
be quickly understood.
[Illustration: FIG. 410.]
MAXIMUM DIMENSIONS OF STEAM FIRE ENGINES.
==================+==========================+===========+============
| LENGTH OVER ALL. | WIDTH | HEIGHT
SIZE OF ENGINE. +-------------+------------+ OVER HUBS.| OVER DOME.
| WITH POLE |WITHOUT POLE| |
------------------+-------------+------------+-----------+------------
Double Extra First|25 ft. 3 in.|10 ft. |6 ft. 7 in.|10 ft.
Extra First |24 ft. 10 in.|9 ft. 10 in.|6 ft. 5 in.|9 ft. 10 in.
First |24 ft. 5 in.|9 ft. 6 in.|6 ft. 2 in.|9 ft. 6 in.
Second |23 ft. 11 in.|9 ft. 1 in.|6 ft. |9 ft. 1 in.
Third |23 ft. 2 in.|8 ft. 11 in.|5 ft. 9 in.|8 ft. 11 in.
Fourth |22 ft. 11 in.|8 ft. 7 in.|5 ft. 9 in.|8 ft. 7 in.
Fifth |22 ft. 3 in.|8 ft. 5 in.|5 ft. 6 in.|8 ft. 5 in.
------------------+-------------+------------+-----------+------------
_Appurtenances._ In addition to such special fixtures as may be
necessary for their proper working, the following articles are a part
of each engine:
Smooth bore rubber suction hose, carried in substantial brackets on
the machine and fitted with suitable couplings, hydrant connections
and interchangeable outside suction strainer.
Polished copper vacuum and air chambers.
Fuel pan of ample capacity.
Detachable footboard, for the engineer and an assistant.
Driver’s seat, for either one or two men.
Seat cushion.
Whip socket.
Blanket holders, when desired.
Foot brake, to operate from front or rear.
Horse pole, with whiffletrees.
Trace and pole chains or straps with patent snaps.
Gong attached to driver’s footboard or
Locomotive bell mounted over steam cylinders.
Steam signal whistle.
Grate bars, dumping or stationary pattern.
Stationary sprinkler, for wetting ashes under grate.
Pop safety valves.
Variable regulator for exhaust nozzles.
Auxiliary steam blast into chimney.
Nickel-plated brass chimney dome and bands around boiler.
Two steam pressure gauges.
Water pressure gauge.
Glass water gauge on boiler with extra tube.
Try cocks on boiler.
Brass feed pump for boiler.
Auxiliary feed to boiler from main pumps.
Churn valve, for feeding boiler when streams are shut off.
Necessary air, drain and pet cocks.
Surface blower from water line of boiler.
Blow-off cocks and cleaning plugs in fire-box leg.
Cleaning and “thaw” hose with connections.
Regrinding throttle valve, with drain cock attached.
Automatic or sight-feed lubricators.
Cylinder oil cups.
Necessary oil cups and lubricating devices.
Hand oil cans.
Three-pint reservoir cans for cylinder and lubricating oil.
Keepers, attached to all stuffing-box nuts.
Poker, shovel and other stoking tools.
Fire department hand lanterns, carried in brackets.
Adjustable screw wrenches.
Universal spanner for slotted nuts.
Hose spanner.
Hammer.
Tool box, with all necessary monkey-wrenches, cold chisels, and files.
Two polished play pipes and nozzles.
Stop valves next to boiler and flow and return pipes for use with
stationary Fire Engine Heaters.
[Illustration: FIG. 411.]
THE SILSBY ROTARY STEAM FIRE ENGINE.
The distinguishing feature of this engine will be found in the fact
that, in both the cylinder and pump, the rotary type is substituted for
the reciprocating or piston principle.
[Illustration: FIG. 412.]
The larger sizes of these engines, Fig. 411, are hung on platform
truck springs in front and on half-elliptic springs in the rear, and
are braced and stayed to withstand violent shocks in the rapid driving
over pavements. Although fitted to be drawn by horses only, they can be
supplied with rope reel and drag rope.
[Illustration: FIG. 413.]
_The Silsby steam cylinder_ consists of two rotary pistons or cams,
mounted on steel shafts and working together within an elliptical
steam-tight case. Live steam from the boiler enters at the bottom
of this case, and in its passage presses apart their long teeth or
abutments, causes the two cams to rotate, and exhausts from the top
into the tank and feed-water heater; these cams are provided with teeth
or cogs, adapted to mesh with corresponding recesses in each other, so
that a steam tight joint is maintained between them and leakage thereby
prevented from passing directly upward into the exhaust.
The sides of these cams have their arcs turned to fit the heads of
the case, and are so adjusted that, while being practically steam
tight, allowance is made for expansion and contraction. In the ends of
the longest teeth of the revolving cams are placed removable packing
strips, which are forced outward into contact with the cylinder walls
by means of springs. These packing strips may be removed through
openings in the sides of the cylinder, and readjusted to take up the
wear, which is confined to the ends of these adjustable strips. This
can be done without taking the pump or cylinder apart.
[Illustration: FIG. 414.]
_The construction of the pump is similar to that of the cylinder_; in
this there are three long teeth in each cam instead of two. One shaft
of the pump is coupled to the corresponding shaft of the cylinder,
there being outside gears on both cylinder and pump to compel a uniform
motion of the cams and to equalize the pressure. This construction
secures a transmission of power at once direct and positive in Fig. 412.
The stuffing-boxes, used on both cylinder and pump, are self-adjusting,
reduce friction and insure tightness. Valves are entirely absent from
the pump and cylinder. The water ways being large, anything liable
to enter the suction will pass through the pump without injury or
interruption; the pump requires no priming, but when started will
immediately without the aid of a check valve lift water vertically any
required distance up to 29 feet.
_The construction of the boiler_ ordinarily supplied with this
engine is shown in Figs. 414-415. In the fire-box hangs a series of
circulating water tubes arranged in concentric circles and securely
screwed into the crown sheet. These drop tubes are closed at their
lower ends by means of wrought-iron plugs welded in, and within each of
them is placed a much smaller and thinner tube, which latter is open at
both ends. The cooler water in the boiler descends through the inner
tube and is thus brought directly into the hottest part of the furnace,
whence, after being for the most part converted into steam, it ascends
through the annular spaces between these inner and outer tubes.
[Illustration: FIG. 415.]
_The gases of combustion_ pass from the fire box to the stack through
smoke flues, the lower ends of which are expanded into the crown sheet,
and the upper ends into the top head of the boiler.
[Illustration: FIG. 416.]
TABLE OF EFFECTIVE FIRE STREAMS.
_USING 100 FEET OF 2-1/2-INCH ORDINARY BEST QUALITY RUBBER-LINED HOSE
BETWEEN NOZZLE AND HYDRANT, OR PUMP._
================================+=======================
Smooth Nozzle, Size | 3/4-inch.
--------------------------------+---+---+---+---+---+---
Pressure at Hydrant, lbs. | 32| 43| 54| 65| 75| 86
Pressure at Nozzle, lbs. | 30| 40| 50| 60| 70| 80
Pressure Lost in 100 feet, | | | | | |
2-1/2-inch Hose, lbs. | 2| 3| 4| 5| 5| 6
Vertical Height, feet | 48| 60| 67| 72| 76| 79
Horizontal Distance, feet | 37| 44| 50| 54| 58| 62
Gallons Discharged per Minute | 90|104|116|127|137|147
================================+=======================
Smooth Nozzle, Size | 7/8-inch.
--------------------------------+---+---+---+---+---+---
Pressure at Hydrant, lbs. | 34| 46| 57| 69| 80| 91
Pressure at Nozzle, lbs. | 30| 40| 50| 60| 70| 80
Pressure Lost in 100 feet, | | | | | |
2-1/2-inch Hose, lbs. | 4| 6 | 7| 9| 10| 11
Vertical Height, feet | 49| 62| 71| 77| 81| 85
Horizontal Distance, feet | 42| 49| 55| 61| 66| 70
Gallons Discharged per Minute |123|142|159|174|188|201
================================+=======================
Smooth Nozzle, Size | 1-inch.
--------------------------------+---+---+---+---+---+---
Pressure at Hydrant, lbs. | 37| 50| 62| 75| 87|100
Pressure at Nozzle, lbs. | 30| 40| 50| 60| 70| 80
Pressure Lost in 100 feet, | | | | | |
2-1/2-inch Hose, lbs. | 7| 10| 12| 15| 17| 20
Vertical Height, feet | 51| 64| 73| 79| 85| 89
Horizontal Distance, feet | 47| 55| 61| 67| 72| 76
Gallons Discharged per Minute |161|186|208|228|246|263
================================+===+===+===============
Smooth Nozzle, Size | 1-1/8-inch.
--------------------------------+---+---+---+---+---+---
Pressure at Hydrant, lbs. | 42| 56| 70| 84| 98|112
Pressure at Nozzle, lbs. | 30| 40| 50| 60| 70| 80
Pressure Lost in 100 feet, | | | | | |
2-1/2-inch Hose, lbs. | 12| 16| 20| 24| 18| 32
Vertical Height of Stream, feet | 52| 65| 75| 83| 88| 92
Horizontal Dist. of Stream, feet| 50| 59| 66| 72| 77| 81
Gallons Discharged per Minute |206|238|266|291|314|336
================================+=======================
Smooth Nozzle, Size | 1-1/4-inch.
--------------------------------+---+---+---+---+---+---
Pressure at Hydrant, lbs. | 49| 65| 81| 97|113|129
Pressure at Nozzle, lbs. | 30| 40| 50| 60| 70| 80
Pressure Lost in 100 feet, | | | | | |
2-1/2-inch Hose, lbs. | 9| 25| 31| 37| 43| 49
Vertical Height of Stream, feet | 53| 67| 77| 85| 91| 95
Horizontal Dist. of Stream, feet| 54| 63| 70| 76| 81| 85
Gallons Discharged per Minute |256|296|331|363|392|419
================================+=======================
Smooth Nozzle, Size | 1-3/8-inch.
--------------------------------+---+---+---+---+---+---
Pressure at Hydrant, lbs. | 58| 77| 96|116|135|154
Pressure at Nozzle, lbs. | 30| 40| 50| 60| 70| 80
Pressure Lost in 100 feet, | | | | | |
2-1/2-inch Hose, lbs. | 28| 37| 46| 56| 65| 74
Vertical Height of Stream, feet | 55| 69| 79| 87| 92| 97
Horizontal Dist. of Stream, feet| 56| 66| 73| 79| 84| 88
Gallons Discharged per Minute |315|363|406|445|480|514
--------------------------------+---+---+---+---+---+---
N.B.—Mr. JOHN R. FREEMAN, member of the New England Waterworks
Association, should have the credit of this carefully arranged
table.—See also page 125 for data relating to Nozzles.
_The Clapp & Jones piston engine_ in design has features peculiar to
itself; Fig. 416 represents one of six sizes, adapted particularly to
city service.
[Illustration: FIG. 417.]
The illustrations, Figs. 417 and 418, _show the vertical pump_ as built
for the larger engines: namely, the sizes known as Extra First, First,
Second, Third and Fourth. The complete engine corresponding to the
detailed views is shown by Fig. 416 on the preceding page.
The principal details are very clear in this engraving. The steam and
water ends, together with the crank and reciprocating mechanism, are
compactly arranged and the complete structure which comprises these
parts is rigidly self-contained. The steam cylinders and valve chest
are cast in a single piece and while this part is firmly secured to the
boiler, all steam and exhaust connections are entirely independent of
these fastenings.
_The Clapp boiler_ is represented in Fig. 419. Reference to the annexed
illustration makes clear the special features of this boiler, which
consist chiefly of a series of spiral water-tube coils arranged within
the fire-box. The coils are of copper and are produced by the seamless
drawn process. Each coil is connected separately to the boiler, and
the spiral form of these tubes permits freedom for expansion and
contraction without strain on the terminal joints. The connections
and the ends of the tubes are made by means of threaded nipples, jam
nuts and corrugated copper washers, and the joints thus made insure
tightness, yet admit of ready disconnection at any time.
[Illustration: FIG. 418.]
The lower ends of the coil tubes are directly joined to the hollow
fire-box walls and the upper terminals are arranged to discharge the
circulated water over the crown sheet. This upward movement of the
water within the spiral coils is caused by the application of heat
to the outer surfaces of the tubes, and the circulation thus set up
induces _a corresponding downward action in the leg of the boiler_. The
circulation, therefore, continues without interruption so long as fire
is maintained on the grate. In operating this boiler the water should
be carried a few inches above the level of the crown sheet, but owing
to the protection afforded by the constant distribution of water over
the crown sheet, the limit of safety is not reached until the water is
nearly out of the fire-box leg.
[Illustration: FIG. 419.]
An improvement in the design of this boiler is _the water-circulating
deflector_, which was devised to occupy the central space within the
coil tubes. This deflector comprises an additional sectional unit,
and its action coincides with the functions served by the coil tubes.
The prime object of this device is to break up and direct the gases of
combustion in a manner that adds to the heat-absorbing qualities of the
coil tubes. See Figs. 420, 421.
Extending from the crown sheet to the top head are the smoke flues,
which are securely expanded at both ends, and through which the gases
of combustion pass from the fire box to the stack.
[Illustration: FIG. 420.]
_The Clapp & Jones Village Engine._ By the illustrations, Figs. 422,
423, 424, etc., it will be noted that the cylinders and pumps are
disposed horizontally and are fitted in a self-contained manner between
bars, which also serve as the main frame of the engine.
The steam cylinders are 8 inches diameter; the pumps 4-3/8 inches,
and the stroke common to both is 7 inches. These sizes are properly
proportioned for effective work and the boiler power provided is ample
to drive the pumping mechanism to its rated capacity of 400 gallons per
minute.
[Illustration: FIG. 421.]
The pumps are fitted with gates permitting two lines of hose to be
worked either independently or at the same time without interference.
The machine is mounted on half-elliptic springs, front and rear, and
the weight of the boiler and pumps is distributed equally over both
axles. The front pair of wheels turn completely under the goose necks,
and the engine can therefore be turned on either hind wheel as a pivot.
The arch of the main frames under which the wheels pass in turning is
immediately forward of the boiler, and the advantage to be noted in
this connection is the reduction in the over-all length of the entire
machine. The front axle is equipped with a rope reel, and the pole is
arranged for either hand or horse draft. The wheels are fitted with
brakes, which are operated from the rear footboard. The engine weighs
about 4,400 pounds. A detail description of the pump and valve gear
follows.
[Illustration: FIG. 422.]
_The valve gear of the Clapp & Jones village engine_ is simple yet
controls the moving mechanism of the two pumps working in unison. Each
pump is driven directly by its own steam cylinder, and the steam valves
are actuated by the positive movement of the opposite piston rod.
The principle is substantially the same as practiced in the “Duplex”
pump construction, and may be readily understood by reference to the
detailed views which are given of these parts in other portions of this
work.
[Illustration: FIG. 423.]
The steam cylinders and pump are self-contained, and aside from the
distinctive difference in the reciprocating gear the design of the
steam and water ends does not differ from the vertical engines of the
Clapp & Jones type.
On these engines intended for use in cold climates _a “thaw-pipe” is
attached_, at the engineer’s side, inside the frame, and is used in
extremely cold weather to prevent the feed-pump, as well as the main
pump and connecting pipes, from freezing. It is operated by means of a
small globe valve. If it is desired to warm the main pump, the two-way
cock used in feeding the boiler should be turned as when feeding
directly from the main pump, when steam will have access both to the
main pump and the feed-pump; but care must be observed not to heat the
main pump too warm. When the two-way cock is closed, and also when
it is open as when feeding from the tank, the steam goes only to the
feed-pump.
After using it to warm the main pump, the two-way cock, should be
closed; otherwise, if the check-valve should happen to stick fast, the
water would pass out of the boiler through the main pump.
_Always keep the globe valve closed when not in use._ It will be
observed that the vacuum chamber upon the suction pipe is located
within the air chamber upon the discharge passage.
The valves of this pump are formed by heavy rubber rings which surround
the pump barrel, as shown in Fig. 423, therefore there can be no
hammering of these valves when the pump is at work.
[Illustration: FIG. 424.]
The rubber rings have slots cut into them at each side of each valve so
that each valve can open and close without stretching the rubber bands.
The steam valve is of the well-known rocker type. The plungers have no
packing excepting water.
[Illustration: FIG. 425.—See page 122.]
NOZZLES.
_The sizes of nozzles named below_ will give the most satisfactory
results, those in italics being the ones best adapted for fire duty.
Also see page 93 for standard sizes of steam fire engines and page 117
for table of effective Fire Streams.
1, Extra first size engine.—1,100 to 1,150 gallons capacity. Through
short lines of hose: _One 1-1/2-inch smooth-bore nozzle, for one
stream_; one 1-3/4-inch ring nozzle, or one 2-inch ring: nozzle;
_1-5/16-inch ring nozzles for two streams_. With 1,000 feet of hose,
one 1-5/16-inch ring nozzle.
2, First size engine.—900 to 1,000 gallons capacity. Through short
lines of hose: _One 1-3/8-inch smooth-bore nozzle, for one stream_; one
1-1/2-inch ring nozzle, or one 1-5/8-inch ring nozzle; _1-1/4-inch ring
nozzles for two streams_. With 1,000 feet of hose, one 1-1/4-inch ring
nozzle.
3, Second size engine.—700 to 800 gallons capacity. Through short lines
of hose: _One 1-1/4-inch smooth-bore nozzle, for one stream_; one
1-3/8-inch ring nozzle, or one 1-1/2-inch ring nozzle; _1-1/8-inch ring
nozzles for two streams_. With 1,000 feet of hose, one 1-1/8-inch ring
nozzle.
4, Third size engine.—600 to 650 gallons capacity. Through, short lines
of hose: _One 1-1/8-inch smooth-bore nozzle, for one stream_; one
1-1/4-inch ring nozzle, or one 1-3/8-inch ring nozzle; _1-inch ring
nozzles for two streams_. With 1,000 feet of hose, one 1-inch ring
nozzle.
5, Fourth size engine.—500 to 550 gallons capacity. Through short lines
of hose: _One 1-1/16-inch smooth-bore nozzle, for one stream_; one
1-1/8-inch ring nozzle, or one 1-1/4-inch ring nozzle; _7/8-inch ring
nozzles for two streams_. With 1,000 feet of hose, one 1-inch ring
nozzle.
6, Fifth and sixth size engines.—300 to 450 gallons capacity. Through
short lines of hose: _One 1-inch smooth-bore nozzle, for one stream_;
one 1-inch ring nozzle, or one 1-1/8-inch ring nozzle, _7/8-inch ring
nozzles for two streams_. With 1,000 feet of hose, one 7/8-inch ring
nozzle.
_The Ahrens steam fire engine_ is not presented as a whole, but Figs.
426-428 show parts of this interesting and widely known apparatus.
[Illustration: FIG. 426.]
The boiler, Fig. 426, is radically different from others, and the
special features making it so popular in the past are the absence of
a crown sheet and smoke flues, coupled with the advantageous manner in
which the water-tube coil sections can be withdrawn from the containing
shell of the boiler. The peculiar arrangement of the tubes compels a
forced circulation of the water, and for which purpose an independent
steam pump is provided. Water drawn from the fire-box leg is forced
through the water tubes, and this relation between the circulating pump
and the other elements of the boiler will be more readily understood by
reference to the illustrations, where Fig. 426 is a sectional, 427 a
top, and 428 a bottom view.
[Illustration: FIG. 427.]
[Illustration: FIG. 428.]
[Illustration: FIG. 429.—See page 141.]
INSTRUCTIONS AND SUGGESTIONS.
_The fire engine is essentially an apparatus adapted to emergencies_,
and owing to the intermittent nature of the duty performed, it is
quite likely, unless the proper precautions are observed, that its
several parts, more especially its interior mechanism, will suffer more
deterioration while standing idle than from actual service.
It is necessary that these interior parts, as well as those more
readily apparent, be cared for with a view of keeping them constantly
in condition to endure the most severe and protracted strains at
the shortest notice. While standing in the house, the engine should
at all times be kept ready for immediate service, with shavings and
kindlings in the fire-box, and as much kindlings and coal in the fuel
pan as can be conveniently carried.
In winter, if no heater is attached to the engine, the room must be
kept warm, to insure against frost.
The machine should be started gradually, but before doing so the
engineer ought to satisfy himself that the joints and connections in
the suction hose are air tight, that the discharge gate is open, the
churn valve closed, that the fire has been properly attended to, the
cylinder cocks open, the exhaust nearly closed, and all the bearings
and journals well oiled, and the wheels properly blocked, especially
if the engine is standing on a grade.
The automatic air cocks on the upper pump heads must be opened
immediately after starting. They serve to promptly relieve the upper
pump discharge chambers of air, and may be closed as soon as water
escapes from their orifices.
When cylinder condensation has nearly ceased, the engine being warm,
the drain cocks should be closed and the machine speeded up gradually
until a good pressure of steam is obtained.
Until the engineer has had some experience with the machine, and is
familiar with its workings, it is not advisable to use more than 90
or 100 pounds of steam, which is all that is required for ordinary
fire duty; the necessity for more than 120 pounds will probably never
arise.
The stuffing-boxes of the engine and pump should be carefully packed.
All of the bearings and journals, as well as the oil cans, should
be well supplied with good oil. The best mineral engine oil is
recommended for this purpose, as it does not gum or change its
viscosity with variations in the temperature of the atmosphere, and
it will endure a higher temperature than animal or fish oil without
injury.
[Illustration: FIG. 430.—See page 141.]
The engineer should keep all joints tight, the stuffing-boxes
properly packed, and all bearings thoroughly oiled.
If the journal boxes or other working parts require taking up,
remember that a little play is preferable to a close adjustment
liable to cripple the engine at a critical moment. To insure perfect
safety, always thoroughly test the apparatus after making such
repairs, by subjecting the parts affected, to the strains usually
encountered in actual service.
The principal requirement of the steam cylinders and slide valves is
proper and constant lubrication. Let this one item be attended to,
and its mechanism will practically take care of itself for many years.
The joints and connections in the suction must be perfectly tight.
Before laying the fire, see that the grate and fire-box are clean,
also that the grate bars are fast, so they will not be liable to jar
out, and that all the steam outlets of the boiler are tightly closed.
Lay on the grate some dry pine shavings—not too many—spread evenly
over the grate, with a few hanging down between the bars; on the
shavings put some finely-split pine or hemlock wood, then some a
little coarser, and finally a quantity coarser still. It is well to
put on the top some finely-split hard wood. These kindlings must all
be dry and split—not sawed—and should be put in loosely, in layers,
the layers being crossed, so that there will be a free circulation of
air between them.
To light the fire: Apply torch (described in page 135) _below the
grate_, never in the door; and while doing so move the torch around
to insure thoroughly igniting the shavings.
When there is a pressure of 40 to 60 pounds of steam, begin throwing
in coal, a little at a time, broken up in pieces about the size
of a man’s fist. Bituminous coal should be used, the same as that
from which illuminating gas is made. It should be of the very best
quality, and very free burning.
Do not put the wood or coal all close to the fire door, but scatter
it about and spread it evenly over the grate.
As soon as the engine is started, coal should be put on often, a
little at a time, and the grate should be kept covered, but not
thickly—say to a depth of three or four inches. Be particular to fire
evenly and regularly, _taking care to cover air holes through the
fire_, and to keep the fire door closed as much as possible.
The grate bars should be kept well raked out from below, and the fire
and coal occasionally stirred off the grate bars inside the fire-box,
using the flat side of the poker for the latter operation.
[Illustration: FIG. 431.—See page 138.]
[Illustration: FIG. 432.—See page 138.]
[Illustration: FIG. 433.—See page 139.]
The water in the boiler should be carried as high as six or eight
inches in the glass tube as soon as the engine gets fairly to work
and a good pressure of steam is raised. The gauges will indicate more
water in the boiler when the machine is running than it will with the
same quantity of water if it is not at work, owing to the expansion
of water by the application of heat.
If there is a tendency to foam, the feed should be increased and the
surface blow-off opened quite frequently to relieve the boiler of the
scum and surplus water. If the foaming is unusually violent, it may
be subdued by stopping the engine for a few moments and permitting
the water to settle.
During temporary stops the fire should be cleaned, by removing the
clinkers and the moving parts of the machinery examined and oiled.
The boiler is usually fed by force pumps, the plungers of which are
secured directly to the yokes of the main engines. Both pumps are
arranged to work in unison; and the supply is generally taken from
the discharging chamber of the main pumps, and is controlled by an
ordinary globe valve. Should the water being delivered by the main
pumps be unsuitable for feeding the boiler, this valve must remain
closed, and a supply from a barrel or tank introduced through the
connection provided for that purpose.
When feeding the boiler, it is a good plan to occasionally feel the
pipe leading from check to boiler with the hand, as one can tell
by this means whether the pump is feeding properly. If feeding all
right, the pipe will be cool. If the pipe is hot, the pump is not
feeding properly, try the pet cock.
Always keep a good torch, ready for use, in the fuel pan. This can be
made by tying some cotton waste on one end of a stick about two feet
long and saturating the waste with kerosene oil.
The kindling should be carefully prepared, and the quantity carried
sufficient to generate a working pressure in the boiler before coal
is added to the fire.
Care should be taken not to use too large nozzles if two or more
streams are being thrown.
Owing to the contracted diameter of fire hose, the flow of the water
is retarded; the loss of power due to friction increases directly
with the length of the line and nearly as the square of velocity. In
other words, if the loss due to a given flow be 12 pounds for 100
feet of hose, then 24 pounds will be required to maintain the same
rate through an additional 100 feet. To double the velocity will
require four times the pressure, or 48 pounds for 100 feet and 96
pounds for 200 feet.
From this brief explanation, it must be plain that the capacity
of any engine is diminished as the length of the line of hose is
increased.
For this reason, the greater the lift the smaller the stream that
can be thrown effectively, and the size of nozzle used should depend
upon the height the water is draughted, reducing it one-eighth inch
for every five feet above a lift of ten feet. If the engine uses a
1-1/4-inch nozzle for ordinary work, it will answer for any lift up
to 10 feet. If water has to be draughted 15 feet, a 1-1/8-inch nozzle
should be used; if 20 feet, 1-inch; and if 25 feet, 7/8-inch.
Never start a fire unless one full gauge cock of water appears in the
boiler.
The suction basket or strainer should always be attached when
draughting water, and every precaution taken _to insure tight
connections in the suction_. The basket must be kept well under the
surface, to avoid clogging if the water be foul.
When the supply is taken from a hydrant, the valve should be fully
turned on; if opened before water is wanted through the hose the
discharge gates on the pumps must be closed. Unless the pressure is
excessive, the hydrant is usually permitted to remain open while
the steamer is attached, the discharge during temporary stops being
controlled by the pump gates.
_The apparatus should always be halted, or placed at a proper point,
with reference to the source of the water supply._ When attached to
a hydrant or plug, do not run the engine faster than the water will
flow to supply the pump, and if the supply is not sufficient to allow
the pump to work to its full capacity, avoid using too large nozzles.
The safety of life and property is very often dependent upon the
skill and good judgment of the engineer, and as the maximum effect
of such apparatus is generally required at the most critical time
and under the most exciting circumstances, it is important that
the endeavor by constant and persistent practice to acquire that
confidence and proficiency that will insure a correct and decisive
action in all matters pertaining to the management of the machine.
From three-fourths to one inch of water should be indicated in the
glass gauge, except when there is a heater attached to the engine,
then from four to five inches should be carried. The bottom of the
glass tube being on a line with the crown-sheet, when one inch of
water shows in the tube, the water-line in the boiler is then one
inch above the crown-sheet.
It is advisable occasionally—say once a month—in towns where fires
are not frequent, to fire up and take the engine out for practice and
drill, and to make sure that it is in proper working order, after
which the boiler should be blown off and refilled with fresh water,
as hereinafter directed.
Every engine required to pump salt water, or other water unfit for
the boiler supply, should be provided with a fresh-water feed tank.
_The purpose of the automatic air cock_ (if there is one) is to
prevent the rattling of the check valves when the pumps are being
only partially filled; if the supply is to be drawn from a barrel or
tank, the entrance of air through this cock must be prevented.
_When draughting the water, bear in mind that the greater the
perpendicular lift the less the quantity of water which can be
pumped_, remembering that it is the pressure of the atmosphere which
forces the water into the pump, and not any power exerted by the
pump itself, which simply produces the vacuum. Thus, the nearer the
surface of the water the greater the velocity with which it enters
the pump, while the higher the pump the weaker the pressure and the
less the quantity of water which enters it, and at a height of about
30 feet no water at all will go into the pump.
If it is suspected that one of the joints in the suction is loose,
the speed of the engine may be slackened without stopping entirely,
until water is thrown eight or ten feet from the nozzle, when if the
pump is taking air the stream will snap and crack instead of flowing
out smoothly. If it is found that the pump is taking air through
the suction, and the leak cannot be located in any other way, it
may be found by removing the suction basket and turning the end of
the suction up higher than the top of the pump, and then filling it
with water. The water will be forced out through the joints wherever
loose, and leaks can be found in this way.
The principal object of _the churn valve_ is to permit the operation
of the pumps without discharging any water through the natural
channels; it controls a passage by which the discharging side of the
pumps is connected with the suction chamber. In draughting water,
when the pumps are first started, _this valve must remain closed_
until the pumps are filled with water, thereby excluding the air
which would find its way into the suction chamber if the same were
open. It should also be closed when the pumps are at rest, to prevent
the dropping of the water into the suction pipe.
When the engine is put to suction, acquire the habit of feeling this
valve to assure its complete closure.
If there is anything about the engine that is not fully understood,
or if it fails to do its work properly from any cause, the maker
should be communicated with at once; inquiries are promptly answered,
and usually required information or suggestions are cheerfully
furnished.
THE AMERICAN STEAM FIRE ENGINE.
_The number of appliances and special devices_ used on and about a
steam fire engine is not large, as it is the aim of both designers
and builders to simplify the machine as much as possible without
diminishing its efficiency.
Fig. 434 is an appliance known as the _Siamese connection_. It is used
for stand pipes attached to the outside of buildings, etc., and also as
a detail of the fire pump. Its use is to lead off two lines of hose.
The valve shown in the figure, closes automatically in case of stoppage
of one of the engines or the bursting of the hose.
[Illustration: FIGS. 434, 435.]
Fig. 435 exhibits an approved form of _strainer_ for the bottom of the
suction pipe.
_The American steam fire engine pump_ is shown in Figs. 431 and 432.
Fig. 431 being the front view, one side of it shown in section,
exposing the interior parts for explanation, and Fig. 432, representing
the side elevation, also in section.
The pumps, which are double acting, are united in a gun-metal casting,
which forms a single body for both, and permits them to be placed much
closer as to centers than could otherwise be done. This method provides
an ample suction-chamber which is common to both.
In cross section the pump somewhat resembles a box girder. This
peculiarity of the pump’s combined form furnishes a rigid base for the
entire structure, simplifies the driving mechanism and enables it to
endure extraordinary strains without vibration.
It will be seen by reference to the cuts that any of the valves can be
easily and quickly examined, and, if necessary, replaced, by simply
removing the caps and heads.
The pump barrels are provided with removable linings, which can readily
be replaced with new ones in case the same should become worn after
years of service. These, as well as the valve seats, are made of gun
metal, no cast iron or other material subject to corrosion by water
being used in any part of the pumps.
Both the suction and discharge valves are supplied with improved valve
springs, the tension of which is, at all times, the same; and being
made of phosphor bronze, the springs retain their elasticity and will
not corrode.
The steam cylinders used in connection with this pump are of the
ordinary slide-valve type, with which most mechanics are familiar, and
are thus easily repaired when necessary. The cylinders and pumps are
detached from the boiler, and are separated therefrom sufficiently
to allow every facility for getting at each and every part. All
connections, both steam and water, are made outside of the boiler.
_The La France steam fire engine pump_ is shown in outline in Fig. 433,
which consists of a double plain slide-valve engine, operating a double
pump.
The steam piston rod of each side connects with its pump rod, by means
of square bars, two of which are on each side of the crank shaft. The
crank is operated by the cross-head through a connecting rod; the
arrangement of these parts can be seen in Fig. 433. The cross-head
guide is entirely done away with, as the stiffness of the connection
between the two piston rods takes the thrust of the connecting rod.
The pump barrel is enclosed by an outer casing. The space between
barrel and casing is always kept filled with water which is supplied
through the suction pipe.
[Illustration: FIG. 436.]
When the pump barrel is being filled with water the suction valves are
lifted from their seats, which allows the water to pass into the space
between the valve-seat plates and thence into the pump barrel.
When the pump barrel is being emptied the suction valves are closed
while the discharge valves are open, which allows the water to pass
into a triangular shaped space between the front plate and valve-seat
plates thence upward to the discharge pipe.
The suction and discharge valve of this pump being all grouped
together, it is only necessary to remove the plates which can be seen,
Fig. 433, bolted to the front of the pumps and form part of the outer
casing; these plates are in front of the pump and may be quickly
unscrewed by a ^T^ wrench.
_The Amoskeag steam fire engine_ is shown in the views (Figs. 429 and
430 on pages 128 and 130). This world widely known machine is made by
the Manchester Locomotive Works at Manchester, New Hampshire, U. S. A.
The former cut represents the extra first, first, second, third
and fourth size double steam fire engine of this make. They have
“crane-neck” frames and are arranged for horse draft and are mounted
upon Endicott’s patent platform springs. The effect of this improvement
is that the draft strain is transmitted directly from the horses to the
axles, the springs bearing no part of this draft strain.
Fig. 430 shows the “fifth” size, also with “crane-necked” frame and
made for either horse or hand draft.
The boiler used is upright and tubular in style, is made of the best
quality of steel plate, with seamless copper tubes, thoroughly riveted
and stayed; it is simple in its construction, and for strength,
durability, accessibility for repairs, and its capacity for generating
steam, has passed a most critical test. For engines of the second
size and larger, the boilers expand downwards at the crown sheet of
the fire-box, thus increasing the grate surface and consequently the
steaming capacity of the boiler.
The connections with the steam cylinders are simple, direct and of
good capacity, peculiarly accessible for repairs, and have _the great
advantage of being entirely unexposed to the air_.
The steam cylinders of the single engines are made in one casting; they
are secured to the boiler framing, and covered with a lagging of wood,
with a metallic jacket on the outside. The pump for the double engines
is made entirely of composition, and its main shell is also in one
casting. It is vertical double acting; its valves are vertical in their
action; the water-ways are free and direct, and the valves accessible,
so that examination or renewal of these parts may be quickly made. The
pump is arranged for receiving suction hose on either side, and has
outlets also on either side for receiving the leading hose.
_Self-propelled steam fire engines_ are well adapted for city service.
In Fig. 436 is shown a double extra, first size self-propelling engine
of the Amoskeag pattern. The road driving power is applied from one end
of the main crank shaft, through an equalizing compound and two endless
chains running over sprocket-wheels on each of the main rear wheels,
permitting these rear wheels to be driven at varying speeds as when
turning corners.
The driving power is made reversible, so that the engine may be driven
either forward or backward on the road at will.
The steering of the engine is effected by means of a steering hand
wheel at the front, adjusting the front axle through a system of
bevel and worm gearing, so arranged that the constant exertion of the
steersman is not required to keep the wheels in line on the road. By
the removal of a key the driving power may be disconnected from the
road driving gearing, when it is desired to work the pumps when the
engine is standing still.
MISCELLANEOUS
PUMPS
[Illustration: FIG. 437. (See page 146.)]
MINING PUMPS.
There are certain well-known difficulties and contingencies in
installing and operating mine pumps: 1, The location of the mine is
usually remote from supplies and any renewals or repairs which may be
needed, are liable to be attended with excessive costs and delays;
2, The nature of the water in the mines is so highly acidulous that
corrosion takes place in an incredibly small space of time. The action
of sulphuric (diluted) acid which is found sometimes as high as two
parts out of a hundred begins at once and continues until the iron or
steel is destroyed; 3, The dust, grit, mud, etc., becomes mixed with
the oil used to lubricate the pump; these ingredients find their way
into the stuffing-boxes and cut the plungers.
Hence, ample and unusual precautions are made to overcome the foregoing
conditions. Extreme care has to be used in securing all movable parts
of the machine and the connecting pipes. The plungers are generally
outside packed and handholes are arranged to permit free access to the
water valves.
[Illustration: FIG. 438.—See page 148.]
When pumps used in mining service assume large proportions, they are
almost invariably described as pumping engines; there is no real
difference between the two except the proportions. The same combination
of engine and pump in the smaller sizes used for boiler feeding, etc.,
are called steam pumps.
NOTE.—The cost of repairing _a half-inch globe valve_ which “gave
out” in a mine in Venezuela, South America, was represented in a $45.
machine charge and a mule ride of 35 miles to the shop containing a
foot lathe and the same distance back to the mines. The cost in a
more favorable location would be less than a dollar.
_The Cataract steam pump_, Fig. 437, is largely used in mining
operations. Many years service has proved its peculiar and curious
merits. Large columns of water may be raised to great elevation or
forced against heavy pressures without shock or jar of any kind and
with safety to the machinery and connections; abrupt and violent action
of the water is also avoided. _The Cataract_, it may be explained, is
a regulator invented by Smeaton for single-acting steam engines. John
Smeaton, the inventor, was an English civil engineer born in 1724 and
died in 1792. The device derives its name from its similarity to the
optical disease—a cataract—as it is a supplementary or sliding cylinder
with its piston attached very curiously _to the main valve stem of the
engine_.
This cylinder—called the Cataract cylinder—_is filled with oil_ which
flows back and forth through a port connecting its two ends. This port
is controlled by a valve which increases and diminishes the flow of
the oil through the port. By means of the Cataract, the movements of
the main steam valve are automatically graduated and controlled, so
the speed of the piston is reduced as it nears the end of its stroke,
allowing the valves to seat themselves gently and quietly, and the
moving column of water to come to a gradual and easy rest.
The claims of this construction of pumps have been thus summarized—
1st. _The speed of the piston is automatically slowed down at the end
of its stroke_, giving time for the column of water to come gradually
to rest, and for the valves to seat gently and quietly, avoiding all
concussion, jar, or the slightest tremor.
2d. _The speed of the engine can be adjusted and automatically
maintained as desired under any pressure._ Should it be working under
full head of steam and against a heavy pressure, and the pressure be
instantly removed the speed would continue unchanged.
3d. _The piston works to the end of its stroke under all pressures_,
avoiding the waste of steam incident to the piston falling short of its
stroke.
It will be understood that there is only a slight waste of oil caused
by the use of this apparatus—all the waste that there is, being the
small amount leaking through the stuffing boxes.
The term “Isochronal,” pump meaning equal spaces in equal times has
been applied to both these pumps and their valve gear.
The sizes, capacities, etc., of the pump described on the opposite page
are given in the following
TABLE.
===+========+==========+=======+==========
|Diameter| | |
|of Steam| Diameter |Length | Size of
No.|Cylinder|of Plunger| of | Steam
|Inches | Inches |Stroke | Pipe
---+--------+----------+-------+----------
1 | 6-1/2| 4 | 20 in.| 1-1/4 in.
2 | 9 | 6 | 3 ft.| 1-1/2 „
3 | 11 | 6 | 3 „ | 1-1/2 „
4 | 14 | 8 | 3 „ | 2 „
5 | 18 | 9 | 4 „ | 2-1/2 „
6 | 20 | 10-1/8 | 4 „ | 3 „
7 | 22 | 12-1/4 | 6 „ | 3-1/4 „
8 | 25 | 14-1/4 | 6 „ | 3-1/4 „
9 | 30 | 16-1/4 | 6 „ | 3-1/2 „
---+--------+----------+-------+----------
===+========+=======+===========+==========+========
| | | Capacity | Capacity |Vertical
|Ordinary|Maximum|at ordinary|at maximum| Lift
No.| Speed | Speed | Speed | speed in | in
| Stroke | Stroke| in Gals. | Gallons | Feet
---+--------+-------+-----------+----------+--------
1 | 50 | 80 | 52 | 85 | 230
2 | 27 | 40 | 110 | 170 | 180
3 | 27 | 40 | 110 | 170 | 290
4 | 27 | 40 | 200 | 300 | 250
5 | 20 | 30 | 275 | 390 | 320
6 | 20 | 30 | 320 | 480 | 320
7 | 15 | 22 | 500 | 750 | 270
8 | 15 | 22 | 700 | 1000 | 250
9 | 15 | 22 | 900 | 1300 | 270
---+--------+-------+-----------+----------+--------
The above table is based on a steam pressure of 45 to 50 pounds per
square inch of steam piston, and the vertical height is from lower end
of suction pipe to discharge.
Fig. 438 is designed to show a pump largely used by miners in
prospecting. It is double levered so that four men or more can operate
it, two to each lever. The plunger and valves are so designed that they
will lift muddy or gritty water without injury to these parts.
An electric mining pump is shown on page 276, part one. This is a
portable pump mounted on a car running on rails and is designed for the
work appertaining to a mine in steady operation.
On page 340, part one, is illustrated a powerful pump with four outside
packed plungers designed for mining purposes.
SINKING PUMPS.
These special mining pumps are used to drain water from the shaft
bottom, so that work in deepening or repairing may be carried on. As
shown in the illustration they are made to be suspended by a chain or
bail attached to eye-bolts in the upper cylinder head at points of
support which will enable the pump to hang vertically and be raised and
lowered at will.
The bail is so constructed that while the pump is suspended the
cylinder head can, if necessary on the smaller sizes, be removed and
the steam piston examined and adjusted. As the shaft gets deeper the
chain may be lengthened out and an extra joint placed on the end of the
delivery pipe.
The sinking pump is subjected to the hardest usage of any, hence any
steam pump that is to be used in sinking a mine shaft must be strong,
certain in operation, capable of handling gritty water and require
little attention.
Fig. 438 exhibits _a hand-power mining pump_, designed especially for
prospecting, etc., and made by the Edson Manufacturing Co., Boston,
Mass. It is listed for three sizes:
No. 6, capacity 1200 gallons per hour, 1 man.
No. 8, capacity 4000 gallons per hour, 2 men.
No. 10, capacity 6000 gallons per hour, 2 men.
[Illustration: FIG. 439.]
_The outfit_ which usually goes with this diaphragm lift and force
pump includes special suction and conducting hose, brass coupling and
strainer; these pumps will raise and force water containing gravel,
sand, dirt or tailings without choking.
_The Deane single vertical sinking pump_ is shown in Fig. 439; a table
of dimensions and capacities of this pump is also given below.
The pump illustrated is double acting and of the differential plunger
type; the water end is in three parts and consists of a water cylinder,
a lower plunger and an upper plunger. The water passes directly up and
through the plungers, both of which are hollow. These plungers are
outside packed. The water valves are reached by hand holes provided for
that purpose. Split pins are used in the ends of the bolts to prevent
the nuts from working off.
These pumps are designed to stand a working pressure of 150 lbs. to the
square inch. They have the regular Deane valve motion and will work
under water.
TABLE.
====================================+=============================
Size. | Capacity.
---------+--------+--------+--------+---------+---------+---------
Diameter |Diameter|Diameter|Length | Gallons | Strokes | Gallons
of Steam |of Large|of Small| of | per | per | per
Cylinder.|Plunger.|Plunger.|Stroke. | Stroke. | Minute. | Minute.
---------+--------+--------+--------+---------+---------+---------
8 | 5-3/4 | 4 | 16 | .87 | 75 | 65
10 | 5-3/4 | 4 | 16 | .87 | 75 | 65
8 | 7 | 5 | 16 | 1.35 | 75 | 101
10 | 7 | 5 | 16 | 1.35 | 75 | 101
12 | 7 | 5 | 16 | 1.35 | 75 | 101
| | | | | |
12 | 11-1/2 | 8 | 16 | 3.48 | 75 | 261
14 | 11-1/2 | 8 | 16 | 3.48 | 75 | 261
16 | 11-1/2 | 8 | 16 | 3.48 | 75 | 261
18 | 11-1/2 | 8 | 16 | 3.48 | 75 | 261
| | | | | |
16 | 14-1/4 | 10 | 24 | 8.16 | 50 | 408
18 | 14-1/4 | 10 | 24 | 8.16 | 50 | 408
20 | 14-1/4 | 10 | 24 | 8.16 | 50 | 408
24 | 14-1/4 | 10 | 24 | 8.16 | 50 | 408
---------+--------+--------+--------+---------+---------+---------
====================================+===================================
Size. | Pipe Sizes.
---------+--------+--------+--------+------+--------+--------+----------
Diameter |Diameter|Diameter|Length | | | |
of Steam |of Large|of Small| of |Steam.|Exhaust.|Suction.|Discharge.
Cylinder.|Plunger.|Plunger.|Stroke. | | | |
---------+--------+--------+--------+------+--------+--------+----------
8 | 5-3/4 | 4 | 16 | 1 | 1-1/2 | 4 | 2
10 | 5-3/4 | 4 | 16 | 1-1/2| 2 | 4 | 2
8 | 7 | 5 | 16 | 1 | 1-1/2 | 5 | 3
10 | 7 | 5 | 16 | 1-1/2| 2 | 5 | 3
12 | 7 | 5 | 16 | 2 | 2-1/2 | 5 | 3
| | | | | | |
12 | 11-1/2 | 8 | 16 | 2 | 2-1/2 | 8 | 4
14 | 11-1/2 | 8 | 16 | 2 | 2-1/2 | 8 | 4
16 | 11-1/2 | 8 | 16 | 2 | 2-1/2 | 8 | 4
18 | 11-1/2 | 8 | 16 | 2 | 2-1/2 | 8 | 4
| | | | | | |
16 | 14-1/4 | 10 | 24 | 2 | 2-1/2 | 10 | 6
18 | 14-1/4 | 10 | 24 | 3 | 3-1/2 | 10 | 6
20 | 14-1/4 | 10 | 24 | 3 | 3-1/2 | 10 | 6
24 | 14-1/4 | 10 | 24 | 4 | 4-1/2 | 10 | 6
---------+--------+--------+--------+------+--------+--------+----------
====================================+====================
| Approximate
Size. | Dimensions
---------+--------+--------+--------+ in Inches.
Diameter |Diameter|Diameter|Length +---------+----------
of Steam |of Large|of Small| of | | Space
Cylinder.|Plunger.|Plunger.|Stroke. | Length. | Occupied.
---------+--------+--------+--------+---------+----------
8 | 5-3/4 | 4 | 16 | 111 | 25 × 23
10 | 5-3/4 | 4 | 16 | 112 | 27 × 24
8 | 7 | 5 | 16 | 111 | 26 × 24
10 | 7 | 5 | 16 | 112 | 29 × 24
12 | 7 | 5 | 16 | 112 | 31 × 24
| | | | |
12 | 11-1/2 | 8 | 16 | 132 | 40 × 32
14 | 11-1/2 | 8 | 16 | 132 | 40 × 32
16 | 11-1/2 | 8 | 16 | 136 | 43 × 32
18 | 11-1/2 | 8 | 16 | 136 | 44 × 32
| | | | |
16 | 14-1/4 | 10 | 24 | 176 | 50 × 38
18 | 14-1/4 | 10 | 24 | 178 | 50 × 38
20 | 14-1/4 | 10 | 24 | 178 | 52 × 38
24 | 14-1/4 | 10 | 24 | 180 | 54 × 38
---------+--------+--------+--------+---------+----------
This table refers to Fig. 439.
[Illustration: FIG. 440.]
[Illustration: FIG. 441.]
_The Cameron vertical plunger sinking pump_ is shown in Figs. 440 and
441.
[Illustration: FIG. 442.]
[Illustration: FIG. 443.]
This is one of the most successful mine sinking pumps designed; there
are no parts exposed to rust, and instances have occurred when this
pump has started off and cleared a shaft of water when the pump itself
had been buried for weeks under a mass of fallen rock and debris.
This pump has no outside valve gear, arms or levers; all movable parts
are inside and enclosed, to prevent collision with the walls of the
mine shaft nor is it likely to receive injury from blast explosions.
Being fitted with special exhaust cut-off, it will continue to run as
fast as steam will drive it (with an irregular or intermittent supply
of water, or when the water fails entirely,) not only without danger of
the piston striking the heads, but without injury to the valves. It is
designed and intended to handle gritty water.
_Telescopic pipe joint_ shown in Figs. 442 and 443, supplies a
convenient means for lifting and lowering a sinking pump, and is
usually made in lengths of sixteen feet. This enables the operator to
drop the pump that distance without disturbing the rest of the pipe; by
its use irregular lengths of pipe can be added, whereas, otherwise when
the pump is lowered the pipe would have to be cut of equal length.
The inside pipe is brass tubing which freely slips through the packing
and is non-corrosive.
Fig. 441 exhibits the sinking pump in practical operation; it is the
same as that shown on the previous page.
NOTE.—Mining pumps require to be made “to gauge” and interchangeable;
an advantage which commends itself to experienced mining engineers.
Many “parts” should be provided in duplicate on account of the rough
usage and hard service alluded to above.
_The “Scranton” pattern of a mining pump_ is illustrated by the cuts
shown below (Figs. 444 and 445).
[Illustration: FIG. 444.]
[Illustration: FIG. 445.]
The plungers of this machine work through middle, exterior
stuffing-boxes, into four separate and distinct water cylinders. The
valve areas and water ways are unusually large in proportion to the
displacement of the plunger, so that the velocity and consequent
destructive action of the water currents is decreased in passing
through the pump.
These pumps are designed to withstand safely a working pressure of 250
pounds to the square inch, and all their attachments are especially
strengthened with a view to meeting the rough usage and hard work to
which they are liable to be subjected in mining operations.
[Illustration: FIG. 446.]
TABLE.
=========+========+======+========+===========+=======
Diameter |Diameter|Length|Gallons |Revolutions|Gallons
of | of | of |Per Rev-|per Minute | per
Steam | Water |Stroke|olution | |Minute
Cylinders|Plunger | | | |
| | | | |
| | | | |
| | | | |
---------+--------+------+--------+-----------+-------
14 | 8-1/2 | 10 | 9.56 | 54 | 516
16 | 8-1/2 | 10 | 9.56 | 54 | 516
18-1/2 | 8-1/2 | 10 | 9.56 | 54 | 516
| | | | |
16 |10-1/4 | 10 | 13.95 | 54 | 753
18-1/2 |10-1/4 | 10 | 13.95 | 54 | 753
18-1/2 |12 | 10 | 19.16 | 54 | 1035
| | | | |
20 |12 | 10 | 19.16 | 54 | 1035
17 | 8-1/2 | 15 | 14.14 | 40 | 565
20 | 8-1/2 | 15 | 14.14 | 40 | 565
| | | | |
17 |10-1/4 | 15 | 20.83 | 40 | 833
20 |10-1/4 | 15 | 20.83 | 40 | 833
20 |12 | 15 | 28.78 | 40 | 1151
---------+--------+------+--------+-----------+-------
=========+========+======+==============================
Diameter |Diameter|Length| Sizes of pipes for
of | of | of | Short Lengths
Steam | Water |Stroke| To be increased as
Cylinders|Plunger | | length increases
| | |-----+-------+--------+-------
| | |Steam|Exhaust|Suction|Delivery
| | |Pipe | Pipe | Pipe | Pipe
---------+--------+------+-----+-------+-------+--------
14 | 8-1/2 | 10 |2-1/2| 3 | 8 | 6
16 | 8-1/2 | 10 |2-1/2| 3 | 8 | 6
18-1/2 | 8-1/2 | 10 |3 | 3-1/2 | 8 | 6
| | | | | |
16 |10-1/4 | 10 |2-1/2| 3 | 10 | 8
18-1/2 |10-1/4 | 10 |3 | 3-1/2 | 10 | 8
18-1/2 |12 | 10 |4 | 3-1/2 | 12 | 10
| | | | | |
20 |12 | 10 |2-1/2| 5 | 12 | 10
17 | 8-1/2 | 15 |4 | 3-1/2 | 8 | 6
20 | 8-1/2 | 15 |2-1/2| 5 | 8 | 6
| | | | | |
17 |10-1/4 | 15 |4 | 3-1/2 | 10 | 8
20 |10-1/4 | 15 |4 | 5 | 10 | 8
20 |12 | 15 |5 | 5 | 12 | 10
---------+--------+------+-----+-------+-------+--------
=========+========+======+==================
Diameter |Diameter|Length| Approximate
of | of | of | Space
Steam | Water |Stroke| Occupied
Cylinders|Plunger | | Feet and Inches
| | |-------+----------
| | |Length | Width
| | | |
---------+--------+------+-------+----------
14 | 8-1/2 | 10 | 9 8 | 3 2
16 | 8-1/2 | 10 | 9 9 | 3 10
18-1/2 | 8-1/2 | 10 | 9 10 | 4 0
| | | |
16 |10-1/4 | 10 | 10 9 | 3 10
18-1/2 |10-1/4 | 10 | 10 9 | 4 0
18-1/2 |12 | 10 | 11 1 | 4 0
| | | |
20 |12 | 10 | 11 2 | 4 2
17 | 8-1/2 | 15 | 10 5 | 3 11
20 | 8-1/2 | 15 | 10 6 | 4 2
| | | |
17 |10-1/4 | 15 | 11 6 | 3 11
20 |10-1/4 | 15 | 11 8 | 4 1-1/2
20 |12 | 15 | 11 9 | 4 3
---------+--------+------+-------+----------
_The Worthington Pressure Pump._ This pump, presented in Fig. 446,
is specially designed for use in connection with hydraulic lifts
and cranes, cotton presses, testing machines, hydraulic riveting
and punching machines and hydraulic presses of all kinds. Also, for
oil-pipe lines, mining purposes and services requiring the delivery of
liquids under heavy pressures.
There are four, single-acting, outside-packed plungers, which work
through the ends of the water cylinders, the latter having central
partitions. The arrangement of compound steam cylinders shown in
Fig. 445, or a triple expansion arrangement, can be applied to these
pumps where a saving of fuel is desired. The water valves are easily
accessible and are contained in small independent chambers, capable of
resisting very heavy pressure.
MARINE PUMPS.
These are made both horizontal and vertical; the prime consideration
being in all cases the amount of floor space the pump will require.
This is especially true in reference to small steam vessels, pleasure
craft, etc.
Owing to the unusual corrosion, caused by galvanic action, salt and
various impurities, marine pumps are built of iron with brass linings,
but frequently with the entire water ends of bronze.
The arrangement of the water valves in the most approved forms of
vertical pumps is such that the pistons are always submerged, and
the water valves sealed, thereby securing immediate lift of water
through the suction pipe, and steady, quiet operation of the pump;
many horizontal pumps of the ordinary duplex design are also used on
shipboard.
_The ship’s pump_ is common to all vessels and used to keep the
“hold” free from water. It is usually worked by hand but it is the
law in certain countries that the “ship’s pump,” aside from steam
vessels—shall be driven by windmill power; it is said to be an odd
sight to see the practical working of these at sea.
[Illustration: FIG. 447.]
The illustration on page 156 shows a marine vertical pump of the
Davidson pattern, designed to work against a pressure of 250 pounds per
square inch. The table given herewith will show the sizes and principal
details of these pumps.
TABLE.
======+======+=======+=========+================+======+=====+=======+======
| | | |Horse-power of | | | |
| | | Gallons |Boiler, based on| | | |
Steam |Water |Stroke,| per |30 lbs. of water|Steam | Ex- |Suction| Dis-
Cylin-|Cylin-|Inches.| Single | per H. P. | Pipe |haust| Pipe |charge
der | der | |Stroke of| per hour, | |Pipe | | Pipe
| | | Each | which the pump | | | |
| | | Piston. | will supply | | | |
| | | | with ease. | | | |
------+------+-------+---------+----------------+------+-----+-------+------
4 | 2-1/2| 4 | .084 | 165 H. P. | 1/2 | 3/4 | 2 | 1-1/2
4-1/2| 2-3/4| 6 | .154 | 300 „ | 1/2 | 3/4 | 2-1/2 | 2
5-1/2| 3-1/2| 6 | .15 | 500 „ | 1 |1-1/4| 3 | 2-1/2
| | | | | | | |
6 | 4 | 8 | .435 | 870 „ | 1 |1-1/4| 3-1/2 | 3
7 | 4 | 8 | .435 | 870 „ | 1-1/4|1-1/2| 3-1/2 | 3
7 | 4-1/2| 8 | .55 | 1,100 „ | 1-1/4|1-1/2| 4 | 3
| | | | | | | |
8 | 5 | 10 | .85 | 1,700 „ | 1-1/2| 2 | 4-1/2 | 3-1/2
8 | 5 | 12 | 1.02 | 2,000 „ | 1-1/2| 2 | 4-1/2 | 3-1/2
9 | 5-1/2| 10 | 1.03 | 2,000 „ | 1-1/2| 2 | 4-1/2 | 4
| | | | | | | |
10 | 6 | 10 | 1.225 | 2,450 „ | 2 |2-1/2| 5 | 4-1/2
10 | 6 | 12 | 1.469 | 2,900 „ | 2 |2-1/2| 5 | 4-1/2
12 | 7 | 12 | 2.00 | 4,000 „ | 2 |2-1/2| 6 | 5
------+------+-------+---------+----------------+------+-----+-------+------
The capacity for boiler feeding in the table is based upon sixty single
strokes for each pump per minute.
The suction and discharge openings, as will be seen in the figure, are
on both sides. The water piston is packed for hot and cold water and
special valves are furnished as may be necessary.
THE “WRECKING” PUMP.
_The Worthington wrecking pump_, Fig. 448, was constructed many
years ago, for wrecking, drainage, or irrigating purposes, and has
proved itself to be remarkably well adapted to such service. It is
used generally by the Wrecking Companies on the Atlantic and Pacific
coasts and the lakes, and is constructed with special reference to
reliability, portability and general efficiency.
It is also well adapted for other services requiring the delivery of
large quantities of water within the range of lift by suction. It
has no forcing power, the water being delivered over the top of the
pump into the curb surrounding it. It is single-acting, although the
discharge is practically constant, by reason of the quick return of
the piston to the bottom of the cylinder, during which inactive stroke
the water continues to flow by the momentum already acquired, thus the
effect of a double-acting pump is almost produced.
[Illustration: FIG. 448.]
The ordinary slide valve is employed, moved by an arm striking against
tappets on the valve rod. No auxiliary valves are used in connection
with it. The water valves are of rubber, the lower ones being upon a
permanent plate at the bottom of the pump. The plunger also is covered
with valves. These last open for the passage of water when the piston
descends.
On account of its short stroke and large diameter, this pump is
extremely efficient, running on comparatively low pressure of steam,
and with a very small percentage of loss from friction or leakage. It
is also simple and durable, with few parts.
The stated capacities of the pumps given in the table can be exceeded
in cases of emergency.
TABLE.
===============+==============+=========+=============+============
Diameter of | Diameter of |Length of| Diameter of | Gallons
Steam Cylinder.|Water Plunger.| Stroke. |Suction Pipe.|per Minute.
---------------+--------------+---------+-------------+------------
6 | 12 | 9 | 6 | 350 to 400
12 | 20 | 9 | 10 |1000 to 1200
16 | 25 | 9 | 12 |1400 to 1600
18-1/2 | 30 | 9 | 14 |2000 to 2300
19-1/2 | 33 | 15 | 16 |3200 to 3600
---------------+--------------+---------+-------------+------------
THE “BALLAST” PUMP.
This machine is constructed to meet the requirements of steamship
builders and is recognized and adopted by marine engineers of this and
of other countries as the standard design for this service and _for oil
tank steamer work_.
It will be observed, see Fig. 449, that its proportions are such
as to secure the advantages of large pumping capacity with unusual
compactness and moderate weight.
This pump is of the packed piston type, and has the valves so
arranged that the water pistons are always submerged, thus making it
particularly well adapted for long and difficult suction lifts such as
are met with in steamers carrying petroleum in bulk, and in steamers
having extensive systems of water ballast tanks.
[Illustration: FIG. 449.]
_The demands for water ballast service_ are generally met by the
following two sizes, as shown in the table below.
TABLE.
================+===============+=========+=================+================
| | | | Diameter of
| | | |Plunger required
| | | | in any single
Diameter of | Diameter of |Length of|Gallons delivered|cylinder pump to
Steam Cylinders.|Water Plungers.| Stroke. | per minute at |do the same work
| | | ordinary speed. | at same speed.
----------------+---------------+---------+-----------------+----------------
6 | 7-1/2 | 6 | 285 | 10-1/4
6 | 8-1/2 | 6 | 375 | 12
----------------+---------------+---------+-----------------+----------------
================+===============+=========+=================================
| | |Sizes of Pipes for Short Lengths
| | | To be increased as length
| | | increases.
Diameter of | Diameter of |Length of|------+---------+-------+--------
Steam Cylinders.|Water Plungers.| Stroke. |Steam | Exhaust |Suction|Delivery
| | |Pipe. | Pipe. | Pipe. | Pipe.
----------------+---------------+---------+------+---------+-------+--------
6 | 7-1/2 | 6 | 1 in.|1-1/2 in.| 5 in. | 4 in.
6 | 8-1/2 | 6 | 1 „ |1-1/2 „ | 6 „ | 5 „
----------------+---------------+---------+------+---------+-------+--------
The purposes for which pumps are used on shipboard, aside from the air
and circulating pumps for condensers, are:
(1.) Feeding the boiler.
(2.) Emptying the tanks and pumping out bilge.
(3.) Supplying water for washing down decks, extinguishing fires,
filling evaporators and sanitary service.
A special pump for each separate purpose is not always supplied, but
one pump may have the necessary pipe connections to serve alternately
various duties.
Feeding the boilers is so important an operation that a supplemental
special pump is always required. To make absolutely sure of an ample
supply of feed water one of the other pumps is made strong enough
to serve the same purpose, or sometimes an injector is fitted as an
auxiliary feeding mechanism.
A bilge pump has special fittings, for the reason that it handles very
dirty water, undesirable to be transmitted through any other pipe
system. In small ships, however, one pump, the so-called “donkey,”
often serves for nearly all other purposes, including auxiliary boiler
feeding.
A special form of pump in use on Western river steamers is the
so-called “doctor,” an independent pump with a walking beam, by which
one steam cylinder drives a system of pumps for feed, fire and bilge
pumping purposes (Fig. 450).
The feed pump should be of simple construction, great strength and
ample capacity, to secure great regularity and reliability of service
under the severe conditions of high pressure.
The main parts of auxiliary feed pumps are often duplicated. This is a
desirable point, as one set of spare parts in piston, rings, valves,
etc., is suitable for both pumps.
The main feed pump is, even in the independent type, often placed in
the engine room, while the auxiliary pump, or the injector, is in the
fire room. The feed pumps draw usually from the hot well, feed heater
and feed tanks and discharge through main feed pipe into the boiler.
_This “doctor” pump_ is a substantial piece of mechanism. The bases of
columns and pump chamber flanges are accurately planed, the cylinder
has spring piston packing and the plain slide valve is made of gun
metal.
The hot water pumps, 3-1/2″ diam. × 10″ stroke, have chambers bored and
are fitted with a copper and tin composition for valves and scats; the
latter are driven into their places and riveted over underneath.
[Illustration: FIG. 450.]
NOTE.—Each valve is reached by removing the bonnet covering it. The
joints under caps are made the insertion of sheet lead. The heaters
above the frame, as shown, are 22″ × 5′ 0″ long, of hard rolled
copper, with a copper worm 18′ 0″ long by 2-1/2″ diameter in each.
There is also a baffle plate above the water line in each heater to
prevent the exhaust from throwing the water out at the top.
HYDRAULIC GAUGE TEST PUMP.
These gauges are apt to get out of order for various reasons namely,
there is no theoretical method of determining the motion of the pointer
due to a given pressure; this is done by tests in which known pressures
are employed, and accordingly the divisions on the graduated scale are
usually unequal, hence these instruments are tested by attaching them
either to a mercury column, or to a dead weight safety valve having for
its seat an exact square inch surrounded by a knife edge, or a piston
of standard area loaded with weights. This sharp edge is covered by a
fibre washer of leather for moderate pressures, say 150 lbs. per square
inch, or vulcanized fibre or its equivalent for higher pressures.
[Illustration: FIG. 451.]
Fig. 451 represents a pump that can be used for pressures up to 10,000
lbs. per square inch. The Hand-Lever Pump shown at the right in cut is
used for filling the Pressure Pump cylinder and connections with oil or
glycerine, and may also serve for testing gauges of low pressures up
to 15 or 20 lbs. The suction pipe _a_ is connected with the reservoir
containing the oil or glycerine, which after being used is discharged
by valve _d_ and returned into the reservoir by pipe _c_.
In filling the pump the cylinder spindle has to be screwed all the way
out, and the valves _b_ and _d_ closed before it is put under pressure.
[Illustration: FIG. 452.]
“SUGAR-HOUSE” PUMPS.
The handling of semi-liquids, commercially known as _thick stuff_, has
always been considered more or less of a serious problem, and many
designs of mechanism in the form of pumps have been invented for that
purpose.
_For pumping tar the improved forms of rotary pumps_ have recently come
largely into use. These will be described later under their proper
heads. Fig. 212, page 232, Part one, represents a very satisfactory
design of plunger pump for handling the heavy stuff alluded to.
_The Deane single sugar-house pump_ is shown in Fig. 452. These are
largely used for pumping molasses, syrup, cane-juice, melter-pan
products, etc., and are fitted with linings, valves, etc., to best suit
the condition of the fluid to be pumped.
The valves are very large and the motion of the pumps is somewhat
slower than for water. By removing one set of bolts all the valves are
uncovered.
These products of the sugar-house when of a high temperature can be
pumped nearly as fast as water; the following list gives the approved
proportions of these pumps.
TABLE.
===========================+=======================
SIZE. | CAPACITY.
--------+--------+---------+-------+-------+-------
Diameter|Diameter|Length of|Gallons|Strokes|Gallons
of Steam|of Water| Stroke | per | per | per
Cylinder|Cylinder| |Stroke |Minute |Minute
--------+--------+---------+-------+-------+-------
4-1/2 | 4-1/2 | 5 | .34 | 125 | 43
5-1/2 | 4-1/2 | 7 | .48 | 125 | 60
6 | 5-1/2 | 7 | .72 | 125 | 90
7-1/2 | 7 | 10 | 1.66 | 100 | 166
7-1/2 | 8 | 10 | 2.17 | 100 | 217
6 | 6 | 12 | 1.47 | 100 | 147
8 | 6 | 12 | 1.47 | 100 | 147
8 | 7 | 12 | 2.00 | 100 | 200
8 | 8 | 12 | 2.61 | 100 | 261
--------+--------+---------+-------+-------+-------
===========================+===============================
SIZE. | PIPE SIZES.
--------+--------+---------+-----+-------+-------+---------
Diameter|Diameter|Length of|Steam|Exhaust|Suction|Discharge
of Steam|of Water| Stroke | | | |
Cylinder|Cylinder| | | | |
--------+--------+---------+-----+-------+-------+---------
4-1/2 | 4-1/2 | 5 | 1/2 | 3/4 | 2 | 1-1/2
5-1/2 | 4-1/2 | 7 | 3/4 | 1 | 3 | 2-1/2
6 | 5-1/2 | 7 | 3/4 | 1 | 3 | 2-1/2
7-1/2 | 7 | 10 | 1 | 1-1/2 | 5 | 4
7-1/2 | 8 | 10 | 1 | 1-1/2 | 5 | 5
6 | 6 | 12 | 3/4 | 1 | 4 | 4
8 | 6 | 12 | 1 | 1-1/2 | 4 | 4
8 | 7 | 12 | 1 | 1-1/2 | 5 | 4
8 | 8 | 12 | 1 | 1-1/2 | 5 | 5
--------+--------+---------+-----+-------+-------+---------
_The Single Magma Pump._ The term _magma_ includes any crude mixture,
especially of organic matters in the form of a thin paste, it also
means “a confection,” hence, the name given to the pump illustrated
in Figs. 453 and 454 is very appropriately applied to a sugar-house
apparatus. It is designed for pumping various thick heavy mixtures and
semi-liquids and for moving massecuite, second and third sugar.
[Illustration: FIG. 453.]
[Illustration: FIG. 454.]
The construction in Fig. 453 is such as to insure strength and
certainty of operation; there are no intricate small parts, and the
interior is readily accessible. These pumps are made with brass-lined
cylinders, or cylinders and fittings entirely of composition when
needed to overcome the difficulties appertaining to pumping acidulous
and corrosive liquid substances.
_The single fly-wheel magma pump_ as shown in Fig. 454 represents the
highest type of machine for this class of work. The steam end is of
the plain slide valve pattern. _It is fitted with a heavy fly-wheel_,
perfectly balanced. The admission of steam is regulated by a throttling
governor of approved design. The fly-wheel and governor insure a
uniform speed of the pump under variations of load—hence the fly-wheel
pump does not require adjustment of throttle for every variation in
water pressure, as is necessary with direct acting pumps.
The following table applies to the two styles of the magma pumps—with
and without the fly-wheel, as the pump ends are the same in both.
Attention is called to the number of strokes per minute (thirty) shown
in the table as compared with the number of strokes (100 and 125)
called for in the previous table. This is caused by the different
viscosity of the stuff to be handled by these machines.
TABLE.
==================================+=============================
|
SIZE. | CAPACITY.
------------+----------+----------+---------+---------+---------
| | | | |
Diameter of | Diameter | Length | Gallons | Strokes | Gallons
of Steam | of Pump | of | per | per | per
Cyl. | Cyl. | Stroke | Stroke | Minute | Minute
------------+----------+----------+---------+---------+---------
5[B] | 3 | 7 | .21 | 30 | 6
5 | 4 | 12 | .65 | 30 | 20
6 | 5 | 12 | 1.02 | 30 | 31
8 | 6 | 12 | 1.47 | 30 | 44
10 | 6 | 12 | 1.47 | 30 | 44
12 | 6 | 12 | 1.47 | 30 | 44
8 | 7 | 12 | 2.00 | 30 | 60
10 | 7 | 12 | 2.00 | 30 | 60
12 | 7 | 12 | 2.00 | 30 | 60
14 | 7 | 12 | 2.00 | 30 | 60
8 | 8 | 12 | 2.61 | 30 | 78
10 | 8 | 12 | 2.61 | 30 | 78
12 | 8 | 12 | 2.61 | 30 | 78
14 | 8 | 12 | 2.61 | 30 | 78
------------+----------+----------+---------+---------+---------
==================================+=======================================
|
SIZE. | PIPE SIZES.
------------+----------+----------+-------+---------+---------+-----------
| | | | | |
Diameter of | Diameter | Length | | | |
of Steam | of Pump | of | Steam | Exhaust | Suction | Discharge
Cyl. | Cyl. | Stroke | | | |
------------+----------+----------+-------+---------+---------+-----------
5 | 3 | 7 | 3/4 | 1 | 3 | 2
5 | 4 | 12 | 3/4 | 1 | 4 | 4
6 | 5 | 12 | 3/4 | 1 | 6 | 5
8 | 6 | 12 | 1 | 1-1/2 | 8 | 6
10 | 6 | 12 | 1-1/2 | 2 | 8 | 6
12 | 6 | 12 | 2 | 2-1/2 | 8 | 6
8 | 7 | 12 | 1 | 1-1/2 | 8 | 6
10 | 7 | 12 | 1-1/2 | 2 | 8 | 6
12 | 7 | 12 | 2 | 2-1/2 | 8 | 6
14 | 7 | 12 | 2 | 2-1/2 | 8 | 6
8 | 8 | 12 | 1 | 1-1/2 | 8 | 6
10 | 8 | 12 | 1-1/2 | 2 | 8 | 6
12 | 8 | 12 | 2 | 2-1/2 | 8 | 6
14 | 8 | 12 | 2 | 2-1/2 | 8 | 6
------------+----------+----------+-------+---------+---------+-----------
==================================+=================
| Approx.
SIZE. | Dimensions
------------+----------+----------+ in Feet
| | | and Inches
Diameter of | Diameter | Length |--------+--------
of Steam | of Pump | of | |
Cyl. | Cyl. | Stroke | Length | Width
------------+----------+----------+--------+--------
5 | 3 | 7 | 4-7 | 1-3
5 | 4 | 12 | 6-11 | 1-5
6 | 5 | 12 | 7-0 | 1-9
8 | 6 | 12 | 7-5 | 2-7
10 | 6 | 12 | 7-7 | 2-7
12 | 6 | 12 | 7-7 | 2-7
8 | 7 | 12 | 7-6 | 2-7
10 | 7 | 12 | 7-7 | 2-7
12 | 7 | 12 | 7-7 | 2-7
14 | 7 | 12 | 7-7 | 2-7
8 | 8 | 12 | 7-6 | 2-8
10 | 8 | 12 | 7-7 | 2-8
12 | 8 | 12 | 7-7 | 2-8
14 | 8 | 12 | 7-7 | 2-8
------------+----------+----------+--------+--------
[B] This size has Tappet valve motion.
CIRCULATING PUMPS.
_The definition of the word circulation_ conveys the best idea of
this mechanism—“The act of moving in a circle, or in a course which
brings the moving body to the place where its motion began,” hence, a
circulating pump is one which causes the water to flow through a series
of pipes or conduits, as for example, the water in a steam boiler as in
the Ahrens Fire Engine, see page 126, Fig. 426, or in marine boilers,
or forces cooling water through a surface condenser.
A centrifugal pump driven by an independent engine, see page 219, Fig.
497, is generally used for the latter purpose.
[Illustration: FIG. 454A.]
The annexed engraving, Fig. 454A, represents a circulating pump attached
to a salt water evaporator and distiller for recovering fresh water
at sea. The pump at the lower right-hand corner of the engraving
takes salt water through the suction at the bottom and passes it
upward through the condenser and overboard through the circulation
discharge. _Any steam pump having a sufficient capacity may be used as
a circulating pump._
ATMOSPHERIC PUMPS.
_The Bliss-Heath Atmospheric Pumping Engine_ represented by Fig. 455
is novel in its construction, consisting of a low-pressure, upright,
tubular steam boiler, having a safety valve loaded to carry 1-1/2 lbs.
steam pressure. The large cover lifts under 2 lbs. pressure, hence
explosions cannot occur.
[Illustration: FIG. 455.]
NOTE.—The safety valve is shown on the floor alongside of the hand
bar arranged to work the feed pump. Fig. 455.
The motor is a simple atmospheric engine operating a plunger pump and a
single acting air pump.
The operation of this motor is almost noiseless.
The motive power is the normal pressure of the atmosphere (14.7 lbs. to
the square inch), utilized by the formation of a vacuum in the power
cylinder.
The air is expelled from the cylinder by admitting steam without
appreciable pressure, _i.e._, to balance that of the atmosphere,
after which the steam exhausts into the surface condenser, in which a
constant vacuum is maintained. Steam is then admitted automatically
into the power cylinder, breaking the vacuum and imparting to the
piston the required impetus. _This principle is identical with that of
the ordinary condensing steam engine_, with the exception of the very
low steam pressure in this connection.
[Illustration: FIG. 456.]
This engine can be operated satisfactorily in combination with an
ordinary house-heating boiler (low pressure), hence the expense of
running it is very low during the steam-heating season. During the
summer months the boiler connected with this engine can be used
advantageously.
The bearings are self-oiling, and the cylinder condensation furnishes
ample protection for the inside of the engine cylinder. There are no
leather packings to burn out, and this is remarkably free from the
objections to the older types of caloric engines.
These pumps when required will force a proportionate quantity of water
to a greater height than fifty feet, upon which the following table is
based:
TABLE OF APPROXIMATE DIMENSIONS AND CAPACITIES.
=======+==========+=============+=============+========+=========
| Gallons | Size of | Approx. | | Size of
Size | Per Hour | Suc. & Dis. | Floor | Height | Smoke
Number | 50 ft. | Pipes. | Space | | Pipe
-------+----------+-------------+-------------+--------+---------
1 | 600 | 1-1/4″ | 43″ × 26″ | 53″ | 5″
-------+----------+-------------+-------------+--------+---------
2 | 1200 | 1-1/2″ | 43″ × 26″ | 58″ | 6″
-------+----------+-------------+-------------+--------+---------
3 | 2000 | 2″ | 48″ × 30″ | 63″ | 7″
-------+----------+-------------+-------------+--------+---------
4 | 3000 | 2-1/2″ | 48″ × 30″ | 63″ | 7″
-------+----------+-------------+-------------+--------+---------
AMMONIA OR ACID PUMPS.
In pumping ammonia it is of the greatest importance that this mechanism
be simple and compact owing to the peculiar properties—oftentimes
dangerous—inherent to ammonia.
The plain slide valve with crank, shaft and fly-wheel probably is less
liable to give trouble than many of the other styles of pumps, _and a
full stroke is always assured_.
The pump here presented (Fig. 456) occupies little floor space and is
easily accessible; the bucket plunger is used and also a slotted yoke
in place of a connecting rod.
The column is in two parts bolted together. In case of accident to
either part duplicates may be quickly substituted.
THE WOOD PROPELLER PUMP.
The pump shown herewith lifts the water by propeller screws or
“runners,” each consisting of two half-circular inclined blades
fastened to a shaft at intervals of 3 to 5 feet, and of slightly less
diameter than the casing, so as to revolve freely within it.
Experiments have demonstrated that more water can be raised with a
given speed by putting the runners close together near the bottom of
the pump.
A bearing for the shaft is placed immediately underneath each of the
runners, and held in position by a set of spring “guides” attached
lengthwise to the well-casing. These guides interrupt the whirling
motion of the water as it is thrown upward by the runners, and turns
it back in the opposite direction, thereby delivering it into the
revolving runners in a direction opposite their motion. By this method
the whirling motion of the water is utilized and the capacity of the
pump largely increased without a proportional increase of power to run
it.
With this pump, water may be raised from several hundred feet below the
surface by extending the shaft and runners down the well-casing to the
desired depth; it being always necessary to submerge the lower runner.
As the shaft rotates the lower runner lifts the water up to the runner
above it, and so on to the next, until the water is delivered at or
above the ground if desired; the distance depending upon the size and
pitch of the runner, the number of runners, and the speed at which they
are driven.
Speed is not increased for additional depth, because more runners are
added, and this compounding of the runners increases the efficiency of
the pump.
A ball bearing is placed over the stuffing-box to carry the entire
weight of all the movable parts of the pump, and also the column of
water. In deep wells cone roller bearings are used in place of the ball
bearings.
The pumps are made to fit all sizes of wells and of any desired
capacity. Runners of various pitches are made for the different sizes
in order to suit the supply of water or the power available. If, after
testing, the supply of water in the well is found to be limited,
the runners are changed to raise the amount of water due to a given
horse-power, then runners can be furnished with a pitch suited to
lifting that particular amount of water.
[Illustration: FIG. 457.]
For example, if one runner at a given speed, gives 10 pounds pressure
per square inch, then two runners would give 20 pounds; three, 30
pounds, and so on. For this reason water may be elevated higher above
the discharge with this pump than with a centrifugal, for it would
require a higher rate of speed to lift a given amount of water 20
feet with one runner, than to lift the same amount 5 feet. Hence the
advantage of compounding the runners as the lift is increased. The
compounding of runners is one of the main features of success and
efficiency of this pump.
[Illustration: FIG. 458.]
Where the water is beyond the suction limit this pump can be used to
raise the water to the surface, discharging into the suction of the
force pump. In this manner, whatever surplus of power the propeller
pump might have in raising the water to the surface, would be utilized
in helping the water through the force pump.
The speed of rotary pumps is generally high, ranging from 800
revolutions per minute for the small sizes to 250 revolutions for
the larger sizes. In a number of experiments made upon this form of
pump the highest efficiency was obtained with pressures ranging from
30 to 50 pounds per square inch, and speeds ranging from 475 to 575
revolutions per minute. The average efficiency of the rotary pump is
from 48 to 52 per cent.
THE SCREW PUMP.
The engraving herewith, Fig. 458, exhibits the general construction
of the Quimby screw pump. The four screws that act as pistons in
propelling the water are mounted in pairs on parallel shafts, and are
so arranged that in each pair the thread of one screw projects to
the bottom of the space between the threads of the opposite screws.
The screw threads have flat faces and peculiarly undercut sides; the
width of the face and the base of the thread being one-half the pitch.
The pump cylinder fits the perimeters of the threads. Space enough
is left between the screws and the cylinder and between the faces of
the intermeshing threads to allow a close running fit without actual
contact. There is no end thrust of the screws in their bearings,
because the back pressure of the column of liquid is delivered through
the suction, S, at the middle of the cylinder, therefore the endwise
pressure upon the screws in one direction is exactly counterbalanced by
a like pressure in the opposite direction.
The suction connection opens into a chamber underneath the pump
cylinder. The suction liquid passes through this chamber to the two
ends of the cylinder and is forced from the ends toward the center by
the action of the two pairs of intermeshing threads; the discharge
being in the middle of the top of the cylinder, as shown at D. The
power to drive the pump is applied to one of the shafts, and the second
shaft is driven by means of a pair of gears, shown at G.
The pump has no internal packing, no valves and no small moving parts.
The only packing is in the stuffing-boxes where the two shafts pass
through the cylinder head.
Whether driven by a belt, an electric motor, or a steam engine,
the driving power is applied directly and without the loss due to
intermediate mechanism; as the screws are not in contact with the
cylinder or with each other, the consequent absence of wearing surfaces
gives the pump great durability.
These pumps have a high efficiency against a wide range of pressures:
The power being applied direct, the thrust due to the back pressure of
the column of liquid in the delivery pipe is balanced.
As the action of the screws on the liquid is continuous, the delivery
is free from pulsation. By thus keeping the liquid in constant and
uniform motion the efficiency of the pump is increased and the pump is
made peculiarly suitable for certain specific purposes as there is no
churning effect upon the liquids handled.
These pumps are much used in connection with hydraulic elevators by
pumping directly into the elevator cylinders, as there is no pulsation.
They are also used to pump oil into pipe lines and are driven by
electric motors as well as by belts. For circulating pumps for brine
and for fire purposes these pumps have certain peculiar advantages.
TABLE OF DIMENSIONS AND CAPACITIES OF THE QUIMBY SCREW PUMP.
=======+========+===========+============================+===================
| | | PIPING |EXTREME DIMENSIONS
| | +-------+----------+---------+-----+------+------
|Gallons |Revolutions| |Discharge | | | |
Size | per | per |Suction| from |Discharge|Width|Length|Height
|Minute | Minute | |Valve Hood| | | |
-------+--------+-----------+-------+----------+---------+-----+------+------
2 | 7-10 | 1200 | 1-1/4 | -- | 1 | 9 | 27 | 11
2-1/2 | 15-20 | 1200 | 2 | -- | 1-1/2 | 9 | 32 | 14
3 | 30-35 | 1200 | 2-1/2 | 2-1/2 | 2-1/2 | 10 | 38 | 16
3-1/2 | 70-85 | 1200 | 4 | 3 | 3 | 11 | 49 | 25
4 |140-170 | 1200 | 4 | 3 | 4 | 13 | 54 | 28
5 |200-245 | 1100 | 5 | 4 | 5 | 14 | 64 | 31
6 |275-350 | 900 | 6 | 5 | 6 | 17 | 75 | 37
7 |400-485 | 775 | 8 | 6 | 8 | 18 | 78 | 38
9 |650-800 | 725 |10 | 8 | 10 | 25 | 92 | 48
10 |825-1000| 575 |12 | 10 | 12 | 32 | 98 | 60
-------+--------+-----------+-------+----------+---------+-----+------+------
Dimensions in inches. Weights in pounds.
AERMOTOR
PUMPS
[Illustration: FIG. 459.]
AERMOTOR PUMPS.
_Aer_ is the first element in many compound words of Greek origin
meaning air, the air, atmosphere; in this connection it is combined
with _motor_, defined as a machine which transforms the energy of
water, steam, or electricity into mechanical energy—in this instance,
is meant the changing of _the power of moving air or wind_ into
mechanical energy.
_Wind is air put in motion._ There are two ways in which the motion
of the air may arise. It may be considered as an absolute motion of
the air, rarefied by heat and condensed by cold; or it may be only an
apparent motion, caused by the superior velocity of the earth in its
daily revolution.
When any portion of the atmosphere is heated it becomes rarefied, its
specific gravity is diminished, and it consequently rises. The adjacent
portions immediately rush into its place to restore the equilibrium.
This motion produces a current which rushes into the rarefied spot from
all directions. This is what we call wind.
_Meteorology_ is the science which treats of the atmosphere and its
phenomena, particularly of its variations of heat and cold, _of its
winds_, etc.
This is the great division of science to which one has to turn when
searching for the first principles relating to the operation of
_aermotor pumps_. The vast volumes of air which flow “hither and yon”
are controlled by physical laws which act as accurately and unceasingly
as those which control and hold in check the seemingly solid substance
of the earth itself.
NOTE.—The portions north of the rarefied spot produce a north wind,
those to the south produce a south wind, while those to the east and
west in like manner, form currents moving in opposite directions.
At the rare spot, agitated as it is by winds from all directions,
turbulent and boisterous weather, whirlwinds, hurricanes, rain,
thunder and lightning, prevail. This kind of weather occurs most
frequently in the torrid zone, where the heat is greatest. The air,
being more rarefied there than in any other part of the globe, is
lighter, and, consequently, ascends; that about the polar regions is
continually flowing from the poles towards the equator, to restore
the equilibrium; while the air rising from the equator flows in an
upper current towards the poles, so that the polar regions may not be
exhausted.
To sum up all observations, it can be said with truth that the
_sole force_ immediately concerned in causing the movements of the
atmosphere, _is gravitation_.
So far as the prevailing winds are concerned it has been shown that
where pressure is high, that is to say, _where there is a surplus of
air, out of such a region winds blow in all directions_; and, on the
other hand where pressure is low, or where there is a deficiency of
air, _towards such a region_, winds blow from all directions in an
in-moving special course.
This outflow of air currents from a region of air pressure upon a
region of low pressure is reducible to a single principle, as already
stated, viz., the principle of gravitation.
A regular east wind prevails about the equator, caused in part by the
rarefaction of the air produced by the sun in his daily course from
east to west. This wind, combining with that from the poles, causes a
constant north-east wind for about thirty degrees north of the equator,
and a south-east wind at the same distance south of the equator.
From what has now been said, it appears that there is a circulation
in the atmosphere; the air in the lower strata flowing from the poles
towards the equator, and in the upper strata flowing back from the
equator towards the poles. It may be remarked, that the periodical
winds are more regular at sea than on the land; and the reason of this
is, that the land reflects into the atmosphere a much greater quantity
of the sun’s rays than the water, therefore that part of the atmosphere
which is over the land is more heated and rarefied than that which
is over the sea. This occasions the wind to set in upon the land, as
we find it regularly does on the coast of Guinea and other countries
in the torrid zone. There are certain winds, called trade-winds,
the theory of which may be easily explained on the principle of
rarefaction, affected, as it is, by the relative position of the
different parts of the earth with the sun at different seasons of the
year, and at various parts of the day.
A knowledge of the laws by which these winds are controlled is of
importance to the mariner. When the place of the sun with respect to
the different positions of the earth at the different seasons of the
year is understood, it will be seen that they all depend upon the same
principle. The reason that the wind generally subsides at the going
down of the sun is, that the rarefaction of the air, in the particular
spot which produces the wind, diminishes as the sun declines, and,
consequently, the force of the wind abates.
From its importance in practical meteorology _Buys Ballot’s law_ may be
stated in these two convenient forms. (1) Stand with your back to the
wind, and the center of the depression or the place where the barometer
is lowest will be to your left in the northern hemisphere, and to your
right in the southern hemisphere. This is the rule for sailors by which
they are guided to steer with reference to storms. (2) Stand with
the high barometer to your right and the low barometer to your left,
and the wind will blow on your back, these positions in the southern
hemisphere being reversed. It is in this form that the prevailing wind
of any part of the globe may be worked out from the charts.
WIND POWER.
It is as _a source of energy_, to be classified with heat, weight of
liquids, electricity, etc., that air in motion (as in a windmill) has a
place as a prime mover.
_Prime movers_, or receivers of power, are those pieces or combinations
of pieces of mechanism which receive motion and force directly from
some natural source of energy. The point where the mechanism belonging
to the prime mover ends and that belonging to the train for modifying
the force and motion begins may be held to include all pieces which
regulate or assist in regulating the transmission of energy from the
source of energy.
_The useful work of the prime mover_ is the energy exerted by it upon
that piece which it directly moves; and the ratio which this bears to
the energy exerted by the source of energy is the efficiency of the
prime mover.
In all prime movers the loss of energy may be divided into two
parts, one being the unavoidable effect of the circumstances under
which the machine necessarily works in the case under consideration;
the other the effect of causes which are, or may be, capable of
indefinite diminution by practical improvements. Those two parts may be
denominated as _necessary loss and waste_.
The efficiency which a prime mover would have under given circumstances
if the waste of energy were altogether prevented, and the loss reduced
to necessary loss alone, is called _the maximum or the theoretical
efficiency_ under the given circumstances.
In windmills, the air, being in motion, presses against, and moves four
or five radiating vanes or sails, whose surfaces are approximately
helical or screw shape, their axis of rotation being parallel, or
slightly inclined in a vertical plane, to the direction of the wind.
_The velocity of the wind determines its pressure_, and the pressure
of the wind against the sails of the windmill determines the power
developed by the mill. A mill of small diameter acted upon by a high
pressure develops as much power as a large mill working under a lower
pressure.
_The mean average velocity of the wind for the entire United States_
is very nearly eight miles per hour. However, for large areas such as
the great plains east of the Rocky Mountains, the mean average is about
eleven miles per hour, and yet in certain small areas situated in the
mountainous districts the mean average velocity is as low as five miles
per hour. Therefore, in selecting and loading a mill, reference should
be had to the wind velocity prevailing in that particular locality. In
general, windmills loaded to operate in ten-mile winds can be depended
upon to furnish a sufficient supply of water.
The variations in the velocity and pressure of the wind are
considerable even within a brief time, and sometimes sudden and
extreme. Winds of 100 miles per hour and upwards are on record. A
very violent gale in Scotland registered by an excellent anemometer a
pressure of 45 lbs. per square foot. During the severe storm at London,
the anemometer at Lloyd’s registered a pressure of 35 lbs. to the
square foot. The gauge at Girard College, Philadelphia, broke under
a strain of 42 lbs. per square foot, a tornado passing at the moment
within a quarter of a mile. At the Central Park Observatory, a wind was
recorded of 28.5 lbs. pressure per square foot.
If the wind were to blow continuously a very small windmill would
suffice to do a large quantity of work and no storage capacity would be
required, but when it does blow it is “free” and experience dictates
that a mill shall be erected sufficiently large to pump enough water,
when the wind does blow, to last over, with the assistance of ample
storage capacity.
Average hourly velocity of the wind at following stations of the U. S.
Weather Bureau, given in miles per hour:
Albany, N. Y. 7
Alpena, Mich. 9
Atlanta, Ga. 9
Atlantic City, N. J. 10.3
Augusta, Ga. 4.2
Baltimore, Md. 6
Bismarck, N. D. 9.4
Boise City, Idaho 4.2
Boston, Mass. 10.2
Brownsville, Tex. 7.4
Buffalo, N. Y. 10
Cairo, Ill. 7.6
Cape Henry, Va. 12.7
Charleston, S. C. 8
Charlotte, N. C. 5.6
Chattanooga, Tenn. 5.5
Cheyenne, Wyo. 10.5
Chicago, Ill. 10.5
Cincinnati, Ohio 6.3
Cleveland, Ohio 9.6
Columbus, Ohio 7.6
Davenport, Iowa 8.5
Denver, Colo. 6.7
Des Moines, Iowa 7
Detroit, Mich. 8.7
Dodge City, Kan. 11.8
Duluth, Minn. 7
Eastport, Me. 0.6
El Paso, Tex. 6.3
Fort Grant, Ariz. 7
Fort Sill, I. T. 10.7
Galveston, Tex. 10.3
Grand Haven, Mich. 10.7
Hatteras, N. C. 14
Helena, Mont. 6.7
Huron, S. D. 11
Indianapolis, Ind. 6
Jacksonville, Fla. 6.7
Keokuk, Iowa 8
Key West, Fla. 9.8
La Crosse, Wis. 7.3
Leavenworth, Kan. 7.1
Little Rock, Ark. 3.6
Los Angeles, Cal. 4.7
Louisville, Ky. 7.3
Lynchburg, Va. 4
Madison, Wis. 10.2
Marquette, Mich. 8.7
Memphis, Tenn. 5.8
Mobile, Ala. 6.7
Montgomery, Ala. 5.1
New Haven, Conn. 8
New Orleans, La. 7.6
North Platte, Neb. 10.3
Olympia, Wash. 3.8
Omaha, Neb. 8.5
Oswego, N. Y. 9.6
Pensacola, Fla. 8.2
Philadelphia, Pa. 10
Pittsburg, Pa. 6
Portland, Me. 8
Portland, Ore. 5.3
Prescott, Ariz. 6.5
Red Bluff, Cal. 7
Roseburg, Ore. 5.3
Sacramento, Cal. 6.7
St. Louis, Mo. 10.3
St. Paul, Minn. 7.6
St. Vincent, Minn. 9.4
Salt Lake City, Utah 5.3
Sandy Hook, N. J. 14.5
San Diego, Cal. 5.6
San Francisco, Cal. 9.4
Savannah, Ga. 7
Shreveport, La. 5.6
Spokane Falls, Wash. 4.7
Springfield, Ill. 8.7
Vicksburg, Miss. 5.8
Washington, D. C. 6.5
Yuma, Ariz. 6
Yankton, S. D. 9
NOTE.—Windmills are erected to be operated by the lightest winds. A
wind which will carry off smoke will move a windmill; and the absence
of a wind of this force means a perfect calm. Mr. Corcoran says: “My
experience of thirty years teaches that a calm has seldom, if ever,
held sway in this part of the world for a longer period than three
days. Consequently, with a tank to hold a three days’ supply, it
becomes possible to pass over any number of calms.”
[Illustration: FIG. 460.]
WIND POWER PUMPS.
Windmills can be divided into two general classes according to the
inclination of the shaft: 1, _Horizontal mills_, in which sails are so
placed as to turn by the impulse of the wind in a horizontal plane,
and hence about an axis exactly vertical; and, 2, _vertical mills_, in
which the sails turn in a nearly vertical plane, _i.e._, about an axis
nearly horizontal.
On account of the many disadvantages connected with the horizontal
windmill, it is seldom brought into use, being employed only in
situations in which the height of the vertical sails would be
objectionable, and this is liable to occur only in extraordinary cases.
In this kind of mill six or more sails, consisting of plain boards, are
set upright upon horizontal arms resting on a tower and attached to a
vertical axis, passing through the tower at its middle part. If the
sails are fixed in position, they are set obliquely to the direction
in which the wind strikes them. Outside of the whole is then placed a
screen or cylindrical arrangement of boards intended to revolve, the
boards being set obliquely and in planes lying in opposite courses to
those of the sails. The result is, from whatever direction the wind may
blow against the tower, it is always admitted by the outer boards to
act on the sails most freely in that half of the side it strikes, or
from which the sails are turning away, and it is partly, though by no
means entirely, broken from the sails which in the other quadrant of
the side are approaching the middle line.
[Illustration: FIG. 461.]
NOTE.—The great objections to the horizontal windmill are: first,
that only one or two sails can be effectually acted upon at the same
moment; and, secondly, that the sails move in a medium of nearly
the same density as that by which they are impelled, and that great
resistance is offered to those sails which are approaching the
middle. Hence with a like area of sails the power of the horizontal
is always much less than that of the vertical mill.
The illustration on page 184, Fig. 460, is a representation of the
_Corcoran windmill_: it contrasts most interestingly with the same
apparatus shown in Fig. 459—a windmill of the early part of the 17th
century.
The figure below, 462, exhibits in detail _the rear view of the
Corcoran mill with the governor_. As the speed of the wheel increases
it swings the “tail” around, so as to bring the wheel at an angle with
the direction of the wind; the latter failing to strike the blades
squarely communicates less force, and in consequence the speed is
diminished; in case of a very high wind the tail turns so as to present
the wheel almost edgewise towards the direction of the blast.
NOTE.—A windmill of this type was erected at a station on the Long
Island R. R. to pump 5,000,000 gallons of water yearly. In order to
test the work of the windmill, a water meter was attached to the pump
during six months, and it was shown that the average work of the
windmill had been 22,425 gallons per day, 4,260,750 gallons during
the time stated and an average rate of 8,000,000 gallons per year.
The weight of water pumped was 16,168 tons gross and was raised to a
height of 66 feet, and the work was done without mishap with little
attention given to the pumping machinery.
[Illustration: FIG. 462.]
Fig. 461 represents a Corcoran double action suction force pump. The
base is hollow and contains the suction and discharge valves; a flange
at the left-hand side receives the suction pipe while a corresponding
flange on the right-hand side connects with the discharge pipe. An air
chamber is attached to the discharge end. The valves may be reached by
removing the bonnets on top of the base.
[Illustration: FIG. 463.]
Fig. 463 is intended to represent an _Ideal steel tank tower_; the tank
is herein located near the top. A _force pump_ is used where water
is delivered into an elevated tank as in this case; a _lift pump_ is
employed to discharge water at the spout and not to elevate above it.
_The common term “Windmill pump” distinguishes a wind power pump from
a hand pump_, the difference being in an extension of the piston rod
above the upper guide with a hole for connection with the pump rod from
the windmill.
Such a pump, with the “pit-man” extending from the pump upwards into
the tower, is shown in Fig. 465. This figure is introduced to show the
tank connections with a regulator on the base of a four-post tower. The
float in the water tank throws the mill in or out of gear according as
the water rises or falls in the tank.
When the tank is filled with water it pulls the mill out of gear and
stops the pump; as a result there can be no overflow or waste. The
tank is thus not allowed to become empty and permit its drying apart,
inducing leakage. But through the medium of the float in the tank, when
the water has been lowered but a few inches, the mill is again put in
gear and the tank refilled to the desired height, at which the float is
set.
NOTE.—These have long been erroneously termed _windmill pumps_ dating
to the time when wind furnished the power for driving _the grist
mills used in grinding grain, etc._ More properly they may now be
named _windmotors_ or _airmotors_.
_The syphon pump_ here illustrated, Fig. 464, is used to force water
from shallow wells to elevations. The cylinder or barrel is situated
within the standard and very convenient for inspection. It has an air
chamber which is detachable.
[Illustration: FIG. 464.]
_The subject of tanks and cisterns_ is one almost vital to the
successful operations of ordinary windmills, owing to the irregularity
of the power to be utilized by the use of aermotors.
In another part of this work this important subject will be further
explained and illustrated.
_One of the most valuable special features of this windmill is its
governor._ It is so contrived that it insures immunity of the mill from
injuries in destructive storms. It consists of a steel coiled spring of
great resiliency, located at the base of the vane frame. Its strength
is of such a character as to hold the wheel in the teeth of the wind
under all ordinary conditions but is sure to yield under greater
pressure.
[Illustration: FIG. 465.]
USEFUL DATA
RELATING TO THE SIZES AND CAPACITIES OF PUMPING MILLS.
TABLE I.
=============+======+======+======+======+======+=======+=======+=======
Size of | 6 | 8 | 9 | 10 | 12 | 14 | 16 | 20
Pumping Mill | | | | | | | |
-------------+------+------+------+------+------+-------+-------+-------
No. Gals. | | | | | | | |
water raised | | | | | | | |
1 ft. hourly,| | | | | | | |
15-mile wind |10,000|20,000|24,000|35,000|68,000|110,000|160,000|300,000
-------------+------+------+------+------+------+-------+-------+-------
TABLE II.
======================+===+===+===+===+===+===+===+===+===+===+===+===
Average wind velocity,| | | | | | | | | | | |
miles per hour | 4 | 5 | 6 | 7 | 8 | 9 | 10| 11| 12| 13| 14| 15
----------------------+---+---+---+---+---+---+---+---+---+---+---+---
Co-efficient | 16| 8 | 5 | 3 | 2 |1.4|1. |.85|.70|.60|.54|.50
----------------------+---+---+---+---+---+---+---+---+---+---+---+---
TABLE III.
=========================+=====+=====+=====+=====+=====+=====+=====
Gallons hourly | 35 | 170 | 220 | 260 | 300 | 360 | 420
-------------------------+-----+-----+-----+-----+-----+-----+-----
Cylinder, diam. in. | 2 |2-1/4|2-1/2|2-3/4| 3 |3-1/4|3-1/2
-------------------------+-----+-----+-----+-----+-----+-----+-----
Discharge pipe, diam. in.|1-1/2|1-1/4|1-1/4|1-1/2|1-1/2| 2 | 2
-------------------------+-----+-----+-----+-----+-----+-----+-----
=========================+=====+=====+=====+=====+=====+======
Gallons hourly | 550 | 850 | 1200| 2200| 3400| 5000
-------------------------+-----+-----+-----+-----+-----+------
Cylinder, diam. in. | 4 | 5 | 6 | 8 | 10 | 12
-------------------------+-----+-----+-----+-----+-----+------
Discharge pipe, diam. in.| 2 |2-1/2|2-1/2|3-1/2| 4 | 5
-------------------------+-----+-----+-----+-----+-----+------
TABLE IV.
================================================================
COMPARATIVE POWER OF BACK-GEARED MILLS.
------------+-----+-----+-----+-----+------+------+------+------
Size of Mill|4-ft.|6-ft.|8-ft.|9-ft.|10-ft.|12-ft.|14-ft.|16-ft.
------------+-----+-----+-----+-----+------+------+------+------
Horse-Power |1/12 | 1/5 |3/10 | 2/5 | 3/5 | 1 | 1-3/5|2-3/5
------------+-----+-----+-----+-----+------+------+------+------
TABLE V.
==================================================
FORCE OF THE WIND IN POUNDS PRESSURE.
----------------+---+---+---+---+---+---+-----+---
Velocity Miles| 8 | 10| 12| 15| 20| 25| 30 | 40
----------------+---+---+---+---+---+---+-----+---
Force Pounds|1/3|1/2|3/4| 1 | 2 | 3 |4-1/2| 8
----------------+---+---+---+---+---+---+-----+---
TABLE VI.
=========================================
POWER OF THE WIND.
------------------+----------------------
Velocity per Hour.|Pressure per Sq. Foot.
10 Miles | 1/2 Lb.
15 „ | 1 „
20 „ | 2 Lbs.
25 „ | 3 „
------------------+----------------------
TABLE VII.
=================================================================
GROSS AND EFFICIENT POWER OF 12 AND 14 FOOT WINDMILLS.
-------------------------+----------+--------------+-------------
| Velocity | Gross | Net
SIZE OF MILL. | of Wind. | Horse-power. | Horse-power.
-------------------------+----------+--------------+-------------
12-Foot Ideal Power Mill | 10 Miles | 1/2 | 1/10
12 „ „ „ „ | 15 „ | 1 | 3/5
12 „ „ „ „ | 20 „ | 2 | 1-3/5
12 „ „ „ „ | 25 „ | 3 | 2-3/5
14 „ „ „ „ | 10 „ | 1 | 3/5
14 „ „ „ „ | 15 „ | 2 | 1-3/5
14 „ „ „ „ | 20 „ | 4 | 3-3/5
14 „ „ „ „ | 25 „ | 6 | 5-3/5
-------------------------+----------+--------------+-------------
The preceding tables are based upon tests of the _Sampson windmill_
as compiled by its makers, The Stover Manufacturing Co.; they deserve
careful study by those planning the introduction of aermotors.
_The power of a windmill_ depends—first, on the diameter of the
wheel; and second, on the velocity of wind. _To increase the diameter
of the wheel is to increase its power_ in proportion to the area of
the squares. Table I gives the horse-power of several sizes of mills
working in a fifteen-mile wind: if the wind velocity be increased or
diminished, the power of the windmill will increase or decrease in the
ratio of the squares of the velocity. Table V will show the comparative
power or force of the wind in velocities from eight to forty miles per
hour for each square foot of surface.
_Rules for approximately determining size of windmill to use._
The daily water consumption must be given as a basis for calculation.
Divide this by 8 to find the hourly capacity of windmill, as if loaded
aright the mill will pump on an average eight hours daily.
_Multiply the quotient by total water lift in feet and with the
co-efficient given in Table II._
The product will in Table I show what mill to use.
The size of the cylinder and discharge pipe will be found in Table III.
[Illustration: FIG. 466.]
Table I gives the maker’s number of the pumping mill, and the number
of gallons each will raise one foot high per hour, with a wind having
a velocity of fifteen miles per hour. Example: No. 9 pump will raise
24,000 gallons of water one foot high in one hour. Now if the water is
to be raised 50 feet then by dividing 24,000 by 50 the quantity raised
becomes 480 gallons per hour.
From Table V it will be seen also that a wind velocity of fifteen miles
per hour develops a power three times as great as an eight-mile wind,
and a twenty-mile wind is twice as powerful as a fifteen-mile, or six
times that of an eight-mile. Hence, _a small increase in velocity
greatly increases the power of the windmill_, while a low velocity
gives but little working force.
From Table VI it is seen that a twenty-five mile wind gives six times
as much power as a ten-mile wind, but really gives twenty-six times
_the net efficient power of the ten-mile wind_, therefore it will not
be proper to calculate on using a power windmill in as low a velocity
as ten miles.
From Table VII it is seen that the net efficient result is six
times as great in a fifteen-mile wind as in a ten-mile wind, and
sixteen times greater in a twenty-mile wind than in a ten-mile wind.
Therefore, _power windmills give best results when working in fifteen
to twenty-five mile winds_. A 12-foot power windmill working in a
fifteen-mile wind will do more work than an average horse, and when
working in a twenty-mile wind will do more work than two average horses.
_Example._—A person in Atlanta, Ga. uses 2,600 gallons of water
daily. He has a well in which the water stands 30 feet from ground
level. To obtain pressure, the water is to be elevated into a tank 50
feet above ground. 2,600 ÷ 8 = 325 gallons to be pumped hourly when
windmill works.
Average wind velocity at Atlanta is 9 miles per hour, answering to
coefficient 1.4 in Table II, and total water lift is 30 + 50 = 80
feet. 325 × 1.4 × 80 = 36,400 gallons.
If first estimate of 2,600 gallons daily was liberal, so that for
instance 2,400 gallons would be sufficient, Table I shows that a
10-foot mill can be used, but to keep on the safe side, choose a
12-foot mill. 325 gallons hourly gives us in Table III 3-1/4-inches
cylinder with 2-inches discharge pipe as proper sizes. If the 10-foot
mill is chosen take the 3-inch cylinder.
A 14-foot windmill working in a fifteen-mile wind will do more work
than two average horses, and when working in a twenty-mile wind will do
more work than four good horses, while in a twenty-five mile wind it
will do more work than six good horses.
_Giving the above tables a practical application_, a little thought
will disclose what a wealth of power stands unappropriated and ready at
hand to do many of the drudgeries of work for which large expenditures
are annually made.
The uses of power windmills are so well understood that it seems out
of place to elaborate upon them; the brief space allowed to giving
information as to the power of this class of mills when working in
different wind velocities, is best expressed in tabular form, Table VI.
Fig. 466 represents the working barrel of a _deep well pump_, such as
are used frequently in connection with the larger sizes of aermotors.
The tube is usually made of heavy brass—this is _drawn_ so perfectly,
as to size and smoothness, that a re-boring is not needed.
The plunger is here shown with four cup leather packings, with one ball
valve; the bottom valve is also a ball with the seat resting within a
conical coupling at the bottom, this with a leather packing makes a
water tight joint.
Should any accident happen to the bottom valve it may be withdrawn by
lowering the sucker-rod until the threaded portion comes in contact
with the nut underneath the plunger. By turning the sucker-rod the
nut engages the thread on the top of the lower valve-cage. Then by
withdrawing the sucker-rod both valves may be drawn up for examination
or repairs.
ROTARY AND
CENTRIFUGAL
PUMPS
[Illustration: FIG. 467.]
[Illustration: FIG. 468. (See page 199.)]
ROTARY PUMPS.
This class of pumps differs from the centrifugal pump, which is
described and illustrated hereafter, in that it includes a _revolving
piston_, while in the centrifugal pump there is a set of _revolving
blades_ which acts upon the liquid in the same way as a fan acts upon
the air; _the centrifugal pump receives the water in the center and
throws it outward, while the rotary gathers the fluid up and leads it
towards a central discharge_.
The rotary pump substantially corresponds to the pressure blower,
and in many cases is simply the rotary engine reversed; while the
centrifugal pump is analogous to the fan-blower. The functions of a
rotary are almost identical with those of piston and power plunger
pumps.
_The rotary pump on account of its cleanliness_ has been quite
generally adopted for pumping all heavy liquids, such as starch, paint,
soap, gummy oils, beer and hops, sewerage, bleachers, etc.
The rotary pump is used also in places where a piston or steam pump
would be objectionable either on account of floor space occupied or for
the reason that steam could not be had without too much expense for
lifting and forcing water and other liquids which would not nor could
not find their way through the tortuous and narrow passages of the
average piston and plunger pumps.
_For low heads of liquids_ the rotary is also somewhat more efficient
than direct acting pumps and the absence of close fitting parts
renders it possible to handle water containing a considerable
quantity of impurities, such as silt, grain and gravel. This type of
pump is compact and is generally self-contained, especially in the
smaller sizes, and will deliver more water for a given weight and
space occupied than the reciprocating types, while its simplicity of
construction not only lessens the liability to derangement, but enables
persons having a limited knowledge of machinery to set up and operate
these pumps successfully.
Rotary pumps are driven by means of belts from line shafting and by
wheel gearing, and also by direct connection to any prime mover such as
a steam or gas engine, hydraulic or electric motor.
_Rotary pumps may be divided into several classes_ according to the
forms of, and methods of working the pistons or impellers, as they are
usually called, that is, according to the construction and arrangement
of the abutments. The abutment receives the force of the water when
driven forward by the pistons or impellers and also prevents the water
from being carried around the cylinder, thus compelling it to enter the
delivery pipe. _In the construction of the impellers or pistons, and
of the abutments, lie the principal differences in rotary pumps._ In
some pumps the abutments are movable, and are arranged to draw back, as
shown in Fig. 469, to allow the piston to pass. In others the pistons
give way when passing fixed abutments, and in others the pistons are
fitted with a movable wing, as in Fig. 472, which slides radially in
and out when passing the abutment.
[Illustration: FIG. 469.]
Pumps of this type having no packing and springs to prevent leakage and
in which the pistons work in cylindrical casings or cylinders are quite
durable and in many instances have been known to run for months without
stopping. The later construction of this pump is shown in Fig. 470;
this design of pump is more economical, as a rule, owing to the fact
that the strain on the belt is uniform at all points in the revolution
of the pistons.
Fig. 467, page 194, represents one of the oldest and most efficient
forms of the rotary pump. Cog wheels, the teeth of which are fitted to
work accurately into each other, are inclosed in an elliptical case.
The sides of these wheels turn close to those of the case so that water
cannot enter between them. The axle of one of the wheels is continued
through one end of the case (which is removed in the figure to show
the interior) and the opening made tight by a stuffing-box or collar
of leather. A crank is applied at the end to turn it, and as one wheel
revolves it necessarily turns the other, the direction of their motions
being indicated by the arrows. The water that enters the lower part
of the case is swept up by the ends of each cog in rotation; and as
it cannot return between the wheels in consequence of the cogs being
always in contact there, it must necessarily rise in the ascending or
forcing pipe.
Fig. 468 represents a pump similarly constructed to the foregoing, _but
having cams_ shaped so as to reduce the wear.
[Illustration: FIG. 470.]
_In Eve’s pump_, shown in Fig. 469, a solid or hollow drum, _A_,
revolves in a cylindrical case. On the drum are three projecting
pieces, which fit close to the inner periphery of the case. The surface
of the drum revolves in contact with that of a smaller cylinder, _B_,
from which a portion is cut off to form a groove or recess sufficiently
deep to receive within it each piston as it moves past. The diameter
of the small cylinder is just one-third that of the drum. The axles
of both are continued through one or both ends of the case, and the
openings made tight with stuffing-boxes. On one end of each axle is
fixed a toothed wheel of the same diameter as its respective cylinder;
and these are so geared into one another, that when the crank attached
to the drum-axle is turned (in the direction of the arrow) the groove
in the small cylinder receives successively each piston, thus affording
room for its passage, and at the same time, by the contact of the edge
of the piston with its curved part, preventing water from passing. As
the machine is worked, the water that enters the lower part of the pump
through the suction-pipe is forced round and compelled to rise in the
discharging one, as indicated by the arrows. Other pumps of the same
class have a portion of the small cylinder cut off, so that the concave
surface of the remainder forms a continuation of the case in front
of the recess while the pistons are passing; and then, by a similar
movement to that in the figure described, the convex part is brought in
contact with the periphery of the drum until the return of the piston.
NOTE.—In the year 1825, one Mr. J. Eve, an American, took out a
patent in England which was practically the beginning of the modern
era of rotary engines and pumps. His pump consisted chiefly of a
revolving cylinder having three teeth or projections and revolved
within a case. A second and smaller cylinder was also placed within
this case. The smaller cylinder had one side scooped out to permit
each of the teeth upon the large cylinder to pass as they came
opposite the small cylinder. The two shafts being geared together the
small cylinder was caused to revolve three times to one of the large
so that the teeth might pass the small cylinder without interruption.
[Illustration: FIGS. 471 AND 472.]
The next improvement in rotary pumps is shown in Fig. 470, page 197.
This type was used for many years as a fire pump. The Silsby fire
engine of the present day is practically this pump in design although
it has packing strips in the center of each of the long teeth of the
elliptical gears.
Following Eve’s invention were a series of claims which embodied the
design shown in the engraving, see Fig. 471, where a sliding partition
or abutment, A, was used to imprison the steam. As the piston or inside
cylinder turned around, the abutment was pushed up and fell of its
own gravity. A strip of metal supported this abutment and furnished
a suitable wearing surface upon the surface of a revolving cylinder
and also accommodated itself to the tilting motion introduced by the
eccentricity of the revolving cylinder.
In Fig. 472 the sliding abutment has been placed in the side of
revolving cylinders and the axis of this cylinder is in its center. In
this case the abutment is pushed in by its pressure upon the inside of
the case and is thrown out by its centrifugal force assisted by spiral
springs.
The engraving, Fig. 468, gives a view of _Gould’s rotary pump_, with
the case removed; long practical experience has demonstrated that the
revolving cams or pistons are of such a shape as to produce the minimum
of friction and wear with the greatest results.
The cases which receive these cams are engine lathe turned and bored
and so true and smooth that the cams when in operation create almost a
perfect vacuum and will “pick up” water for a long distance and hold it
efficiently. The cams are carefully and accurately planed to mesh into
each other to fit their case.
It is a point worth noting that if a little good oil be put into the
case of these pumps before and after using at first, or simply to pump
air with the oil a few times, the cams become as hard upon the surface
as tempered steel, and are almost unaffected by long use afterwards.
Drip plugs are provided for draining pumps in cold weather. To do this,
turn the cams backward a single revolution to release all water.
_The Taber pump_ is one of the best known of the rotary class. It
consists of three parts only, that is to say, (1) the outside shell or
case, (2) the piston, and (3) the valves.
Referring to the engravings herewith (Figs. 474 to 481), the outside
case or shell, A, is made either of brass or iron as the case may be,
Fig. 476, bored out at F to receive the piston, C, Fig. 478, to which
power is applied at G.
[Illustration: FIG. 474.]
This cylinder has two heads or covers, BB, Figs. 475 and 477, which
close the cylinder and has journal bearings to carry the piston
combined with packing boxes to prevent leakage of the liquid passing
through the pump. The valves, Figs. 479, 480 and 481, DDD, are plates
of composition which slip through the piston fitting neatly into the
slots, EE, Fig. 478.
[Illustration: FIGS. 475-477.]
[Illustration: FIG. 478.]
[Illustration: FIGS. 479-481.]
These valves really perform the work of pumping. It will be observed
that substances which would easily clog up an ordinary pump with clack
valves, will pass through this pump without difficulty; there are no
springs in this pump, nor will it get out of order with the average
treatment, and it pumps all kinds of liquids, either thick or thin,
such as are found between the two extremes of water, and _brewers’
grains_.
It is designed to handle a large amount of fluids and semi-fluids under
a medium pressure, and being well balanced it may be run fast or slow
as desired.
_Directions for setting and operating Taber pumps._
1st. Bolt pump firmly to the floor, and if possible set it so that the
liquid runs into it, which will add very much to the life and duty of
the pump.
2nd. See that all parts are well oiled.
3rd. Experience has proved that common candle wick soaked in tallow is
the best material with which to pack rotary pumps. The wick should be
double and twisted into a compact rope and driven into the boxes as
tightly as possible with a piece of hard wood tapered to fit the box.
Such a tool as described is furnished with each pump. Do not under any
circumstances use iron calking tools which mar the bearing and causes
them to quickly cut out the packing.
4th. If from any cause the pump should become clogged, do not use a
lever in starting it. Remove the plug from bottom and work the pulley
back and forth till the pump is relieved. If this does not free it,
remove the outside head and all parts will be accessible.
NOTE.—Many of the modern breweries are built with the hop-jack
situated upon the upper floors of the brewery, to which the beer
and hops mixed are pumped, and the beer allowed to flow directly
to the coolers. This pump has been very successfully installed for
the past five years, pumping in some breweries 90 feet in height
above the pump. The handling of wet brewers’ grains by use of chain
conveyors, which are seldom free from infection and which are a
continual source of annoyance from breakage, is now overcome by this
pump. All styles of these pumps can be washed out clean after use,
thereby overcoming entirely the noxious smell so disagreeable to this
part of the brewery when conveyors are used. There should be a fall
of six to eight feet from the wash-tub into the pump and as nearly
perpendicular as possible. Right angle bends in the discharge pipe
should also be avoided. By using twenty-four-inch bends wet grains at
70% moisture can be pumped without additional water.
When putting heads back on the pump use ordinary _newspaper for
packing, nothing thicker_, as thicker packing destroys the suction.
Prevent all leaks in suction pipe which would impair the vacuum.
The suction should furnish an uninterrupted supply to the pump, to
enable the pump to throw its full capacity. Never use pipes smaller
than the openings in pump.
Open all drips in cold weather to prevent freezing.
All packing boxes should be kept in order and never allowed to leak.
The illustration, Fig. 482, page 204, represents a rotary pump of the
Holyoke pattern to be attached by a clutch to a line shaft—the gears,
as shown, are merely to transmit the power to the impellers. The safety
valve with lever and weight, shown in the cut, are designed to be
attached to the discharge pipe to guard against over pressure, which
might occur through the closing of valves.
Fig. 483 shows an emergency pump of the Holyoke rotary pattern. It
is of the same general design as the one previously alluded to. It
is driven directly from the line shaft by friction gearing instead
of toothed wheels. The hand wheel attached to the end of a screw is
used to press the smaller friction wheel against the larger and thus
transmit the power to drive the pump.
This mechanism is not liable to injury by being thrown instantly into
gear in case of fire, as would be the case if gear wheels were used.
These pumps are largely used in mills located in the Eastern United
States, _as they may be started up in a few moments at full speed_
without slowing down the engine or motor driving the line shaft.
The shaft bearings are all made of large proportions to avoid heating
and excessive wear when suddenly put under full load.
[Illustration: FIG. 482.]
[Illustration: FIG. 483.]
Figs. 484 and 485 are views of a _rotary pump driven by steam_ and
largely used for fire apparatus. These pumps are in general use in
mills and factories, and can be installed wherever the necessary steam
and water supply are available.
The pump is built on a rigid iron base plate, and is furnished with air
chamber, water-pressure gauge, oil feeders and everything necessary to
make it complete and ready for permanent steam and water connections.
The discharge outlets can be adapted for forcing water through either
pipe or hose.
A perspective view of this pump is given in Fig. 484 and a sectional
plan of the same appliance appears in Fig. 485.
Both engine and pump are of the rotary type and the construction of
these parts is precisely as described in connection with its adaptation
to use in the Silsby steam fire engine.
These pumps can be thoroughly drained and, with their interior surface
well coated with oil and No. 2 pure Graphite, they can be “laid up”
indefinitely and with certainty as to their starting promptly when
wanted in an emergency. Water accumulated in the steam pipe will pass
through this cylinder without causing damage, and the free action
of the pump will not be defeated by the “sticking” of valves or the
corrosion of exposed parts.
In the operation of rotary pumps trouble is often experienced through
an improper adjustment of _the ends of the case_. If the case is too
long there will be leaks of water pass the ends of the impellers and on
the other hand if the case is too short the ends of the impellers will
bind and cut, through excessive friction. Hence great care is necessary
in adjusting the ends of the case so that the pump may run freely yet
without leaks. The packing boxes around the shafts must not be screwed
up too tight otherwise the shaft will be injured.
It has been found by costly experience that _for emergency fire pumps
leather belts are unreliable_, hence these two pumps, Figs. 482 and
483, are driven by direct connection with the shaft in the first
instance and through cast iron friction gearing in the second.
[Illustration: FIG. 484.]
[Illustration: FIG. 485.—See page 205.]
[Illustration: FIG. 486.—See page 210.]
The engraving, Fig. 487, shows _Root’s rotary pump_. This has two
impellers which are geared together and each turn at equal speeds
towards one another at the top. The engraving, Fig. 488, also shows
a Root pump with _two impellers each having three wings or lobes_.
The pump proper consists of half circles, _AA_, with air chambers,
_DD_, cast with them, the head plates, _B_, carrying the bearings,
and the revolvers, _CC_, together with shafts, _EE_. The shafts carry
involute gears at each end which keep the lobes of the two impellers
in their relative positions, and rotate them. Either shaft may be made
the driving shaft and to deliver water, as shown by the arrows in the
cross section, the shafts revolve so that the tops move toward one
another.—Same as in the preceding case.
[Illustration: FIG. 487.]
[Illustration: FIG. 488.]
_The action of this pump is as follows_: the suction pipe on starting,
being full of air, the first few revolutions of the pump expel the
air until the required vacuum is formed, which allows atmospheric
pressure to raise water into the pump. It then flows between the case
and the lobes into the space, _F_, and is carried by the impellers
to the discharge edge of the case, point, _G_, where it enters the
discharge pipe. Each succeeding lobe brings up an amount of water
equal to spaces, _FF_, thus delivering the contents of the six at each
revolution. The irregular form of the lobes keeps them in contact at
the center line, thus preventing the return of water into the suction
below.
Heads of water from 10 to 250 feet are successfully handled by this
type of pump, with a slip of from 5 to 15 per cent., according to the
discharge pressure.
The three-lobe impellers provide a double lock against the return of
water between the case and impellers, at the same time allowing a very
free inlet and outlet for the water. The delivery of water from this
pump is smooth and continuous.
The large engraving, Fig. 486, page 208, shows the exterior of this
same pump with journal bearings and gears encased at each end. This
pump may be driven by motor or engine.
_Large rotary pumps for dredging purposes_ with their engine equipment
for _salt water service_, include surface condenser outfits with air
pumps, feed pumps, fire pumps, etc. The dredges _for fresh water_
are very large cross-compound engines, double-acting air pumps
and jet condensers with the usual complement of vertical duplex
feed pumps, fire pumps, etc. The air pumps are of a very novel
arrangement, inasmuch as it is possible by the manipulation of valves
and cocks provided for the purpose to separate the pumps and run
one side entirely independent of the other side. These dredges are
self-propelling and sea-going; some of them are fitted with immense
bins in which the dredged material is deposited, and when full, the
vessel propels herself out to deep water, dumps the sand or mud and
steams back to repeat the operation.
NOTE.—The operation of these machines is very interesting. A long
flexible tube 12 to 15 inches in diameter drops down from the side of
the vessel 20 to 30 feet or more to the bottom of the river or harbor
upon which the dredging operation is being performed. The upper end
of this tube is connected to an immense rotative centrifugal pump
revolving at several hundred revolutions per minute and capable of
handling many hundreds of tons of water per hour. The lower end of
the tube is manipulated from the vessel against the sand bars and mud
banks and as the water is sucked upward by the centrifugal pumps a
very large proportion of sand and mud goes with it. The centrifugal
pumps discharge this water with its suspended material into the tanks
on board the vessel or into scows, where the heavy material quickly
settles to the bottom, the water flowing back into the sea.
The mixture of sand and water which is drawn up the suction pipe is
forced a distance of 3,800 feet through a 30-inch pipe to the place
where it is to be deposited; the water draining off allows the solid
matter to remain.
CENTRIFUGAL PUMPS.
_The centrifugal pump raises the liquid to be displaced, by means of a
rapidly revolving fan_ having two or more blades straight or curved,
fastened upon a shaft and fitting closely into a case having an inlet
for water at the end center and an outlet at one side or on top of the
case tangent to the circle described by the fan.
Most people are practically acquainted with the principle of the
centrifugal pump, viz., that by which a body revolving round a center
tends to recede from it, and with a force proportioned to its velocity:
thus mud is thrown from the rims of carriage wheels, when they move
rapidly over wet roads; a stone in a sling darts off the moment it is
released; a bucket of water may be whirled like a stone in a sling and
the contents retained even when the bottom is upwards.
_The earliest history of the centrifugal pump_ cannot be traced, but
it is known that centrifugal machines for lifting liquids were in use
during the latter part of the seventeenth century. About 1703, Denis
Papin, the famous French engineer, designed his “Hessian Suck,” a form
of centrifugal pump embodying nearly all of the essential features of
the present-day machine. Drawings of this pump are in existence which
show that Papin was not only a designer of no mean ability, but that he
had a good comprehension of the principles with which he was dealing.
After Papin there seems to have been no further development of his
ideas until 1818, when the earliest prototype of the present form of
centrifugal was brought out in Massachusetts and has since been known
as the “_Massachusetts pump_.” This pump was of the type designated
“volute,” and was provided with double suction openings and an open
impeller. It was re-invented by Andrews and others in 1846, and was
shortly afterwards introduced into England by Mr. John Gwynne.
NOTE.—The term “volute” so frequently used in connection with these
means “_a spiral scroll of plate_.”
Centrifugal pumps have now attained a degree of perfection, which makes
them a serious rival of the plunger pumps. The high-class turbine pumps
of to-day are simply machines in which the water is given a velocity
which is partially changed to pressure before discharge, and the pump
is designed so that the well-known actions, outlined above, proceed
along natural lines, which are, to use the common phrase, lines of
least resistance. It is simply a question of careful design.
The modern pump causes the water to flow along paths naturally due to
the forces acting and to guide the stream in such a way as to avoid the
production of eddies and whirls within itself which so enormously cut
down the efficiency.
[Illustration: FIG. 489.]
The blades now take the form of “impellers” which have warped surfaces
whose form is the result of careful calculation, and the water, after
leaving the impellers, is guided by vanes of equally and carefully
calculated form. _It is owing to the correct form of the guide vanes_
that the nearly perfect conversion of velocity into pressure head is
possible, and this is the principal factor which produces the high
efficiency shown in tests.
When pumping against high heads, the units are arranged in stages or
series. The discharge from one is led to the inlet of the next in
series, the separate units being usually mounted on one shaft, and the
whole really forms one machine. In this manner heads approaching 2,000
feet are worked, still preserving the high efficiency which in some
cases reaches between 80 and 90 per cent.
The ability to generate such pressures enables them to be used for
feeding boilers, and their efficiency particularly commends them for
this purpose.
[Illustration: FIG. 490.]
The centrifugal pump is _the converse of the turbine water-wheel_. Its
development has been analogous to that of the steam turbine in that
both were abandoned in favor of reciprocating machines before having
been thoroughly exploited; the pump because the principles of its
action were not clearly understood, and the steam turbine because of
mechanical difficulties in its construction.
Opposite the title page of this book can be seen a representation of
a centrifugal wheel of _ten thousand horse power_; it will repay the
careful student to consult also page 133 of part one of this work
for the details of this enormous machine; the curious will also be
interested in an early form of the centrifugal pump to be seen in Fig.
489 and its description in the Note on page 214.
[Illustration: FIG. 491.]
[Illustration: FIG. 492.]
Where large quantities of water are to be moved quickly and more
especially in cases where the water is impure and contains floating
matter, as well as sand, mud, coal and the like, as in wreckage, the
centrifugal pump has its peculiar advantages. It is suited particularly
for use in tanneries, paper mills, dry docks, corporation work such
as building sewers, sand dredging, and with water that contains large
quantities of solid matter held in suspension. Pumps used for these
purposes have to be primed on starting, and the suction pipe should
be as short as possible. Long suction pipes very much impair the
efficiency of this type of pump. They will draw water upwards of twenty
feet but nothing like the full capacity of the pump can be realized
under such circumstances. It is always better to lower the pump as much
as possible and force the water instead of trying to suck it.
NOTE.—Upon page 212 is represented one of the very earliest types
of a turbine pump, an account of which is left by Ewbanks, to whose
book on hydraulics credit should be given for the figure. “This pump
consists of tubes united in the form of a cross or letter ^T^ placed
perpendicularly in the water to be raised. The lower end is supported
on a pivot; perforations are made to admit the water, and just above
them a valve to retain it when the pump is not in motion. The ends
of the transverse part are bent downward to discharge the water
into a circular trough, over which they revolve. To charge it the
orifices may be closed by loosely inserting a cork into each and then
filling the pump through an opening at the top which is then closed
by a screw-cap. A rapid rotary motion is imparted to the machine by
a pulley fixed on the axis and driven by a band, from a drum, &c.
The centrifugal force thus communicated to the water in the arms
or transverse tube, throws it out; and the atmosphere pushes more
water up the perpendicular tube to supply the place of that ejected.
These pumps are sometimes made with a single arm like the letter ^L^
inverted; at others quite a number radiate from the upright tube. It
has also been made of a series of tubes arranged round a vertical
shaft in the form of an inverted cone. A valuable improvement was
submitted by M. Jorge to the French Academy in 1816. It consists in
imparting motion to the arms only, thus saving the power consumed in
moving the upright tube, and by which the latter can be inclined as
circumstances or locations may require.”
Centrifugal pumps designed to raise clean water alone should not be
used for any other purpose, that is to say, pumps for handling more
or less solid matter mixed with the water have much more clearance in
the case than those for pumping clean water. The fan is also made
differently so that it cannot be clogged up by lumps of coal, gravel,
and sticks of wood. The accompanying engravings, Figs. 490, 491 and
492, illustrate these ideas, showing the three progressive grades of
fans for the kinds of work alluded to.
Fig. 490 shows a fan with hollow arms for clean water only.
Fig. 491 shows the disc type of fan for water containing grit, pulp,
etc.
Fig. 492 exhibits a fan used in dredging pumps used for all sorts of
stuff that will pass through the connecting pipes.
[Illustration: FIG. 493.]
There are two general types of centrifugal pumps, viz., 1, _single
suction_, Fig. 493, in which the suction pipe enters the end of case
parallel to, and in line with its center; 2, _the double suction_,
Fig. 494, in which the suction pipe is divided forming a ^U^ shape and
enters the case at both sides of the center.
The single suction is used for clear water only, while the double
suction will pass everything that enters the suction pipe—see
engravings.
When the pump is located above the water, it has to be primed before
it will raise water. For these purposes an ejector, or exhauster, is
frequently employed, which will exhaust the air and draw water up from
the required depth. The arrangement of the ejector is illustrated at
A, in Fig. 496, and is the smallest and most convenient contrivance
that can be used for this work. It is screwed into the highest part of
the pump, and is connected by a separate steam pipe to boiler. In a
short time after turning on steam, the pump will be primed, the pump
remaining stationary during the operation of priming.
[Illustration: FIG. 494.]
To prevent air returning through the discharge pipe, a check valve, B,
is used. For larger pumps a gate valve is generally employed here.
A foot valve fitted with a strainer to keep out obstructions likely to
clog the pump should be used as it keeps the pump primed and ready for
immediate use.
The general form of the blades is of great importance in this type
of pump, because the water is driven through the fan partly by the
pressure of the blades on the water and partly by centrifugal force.
The ratio which each of these forces bears to the other varies in the
same pump, depending upon the proportion the speed bears to the height
of it. With low lifts and high speed the water is discharged with but
little rotary motion, the resistance to the outward motion of the water
being so small that the oblique action of the blades is sufficient to
effect the discharge without imparting to the water the same speed of
rotation as is given to the fan. The principal object in this type
of pump is to effect the discharge of as large a volume of water as
possible with the least rotary motion. The power absorbed in imparting
the latter motion is not given up later on and consequently is lost,
while the rotary motion tends to impede the flow of water.
[Illustration: FIG. 495.]
The passage through the pump should be so timed as to produce a
gradually increasing velocity in the water until it reaches the
circumference of the fan, then a gradually decreasing velocity until
it is discharged from the pipe. These conditions are met by having a
conical end to the suction pipe, and a spiral casing surrounding the
fan. The form of the casing should be such that the water flowing round
the casing will move with the same velocity as that issuing from the
fan; the casing enlarges from that locality into the discharge pipe.
A small increase in the number of revolutions of the fan after the pump
commences to discharge produces a large increase in the volume of water
delivered.
[Illustration: FIG. 496.—For description see page 216.]
Fig. 495, upon the previous page, is intended to show a _Boggs & Clarke
hydraulic dredging or sand centrifugal pump_. This is a heavy strong
pump fitted with flap valve, _without close fitting joints_, but with
ample room for the water to wash away the sand from the working parts.
The cut shows the pump with ejector for priming and large elbow to
discharge through. The pump is lined with sheet steel fitted so that it
can be easily and cheaply replaced. The diameters in which these pumps
are made run from 4 to 12 inches inclusive.
TABLE.
=========+======================+=========+==================
Size of | Pipe Size of Flanges | Size of | Capacity per Hour
Pump | Discharge | Suction | Pulley | Cubic Yards Sand
---------+------------+---------+---------+------------------
4 | 4 | 5 | 12 × 10 | 30 to 40
5 | 5 | 6 | 12 × 10 | 40 to 60
6 | 6 | 8 | 18 × 12 | 60 to 80
8 | 8 | 10 | 24 × 12 | 80 to 125
10 | 10 | 12 | 30 × 12 | 150 to 250
12 | 12 | 14 | 36 × 14 | 250 to 400
---------+------------+---------+---------+------------------
[Illustration: FIG. 497.]
Smaller sizes for pumping sand and gravel are made with cast chilled
linings with chilled piston, and brass covered shaft especially adapted
for stone and marble mills to carry the sand to the saws, or for mining
where there is a large quantity of sand to be pumped with water.
The table will convey an idea of the capacity, sizes, etc.
For pumping sand or heavy material the speed of pump should be
increased 25% more than for water.
[Illustration: FIG. 498.]
The engraving Fig. 497 exhibits a _steam-driven centrifugal pump_ of an
approved design constructed by the _Morris Machine Works_.
This pump is directly connected to the engine and has a double
suction. Pumps directly connected to engines are to be preferred over
belt-driven pumps when conditions of elevation, etc., will allow, as
they are self-contained, take up less space and are more economical.
The figure 498 shows a 20-inch _hydraulic dredge_, directly connected
to a 450 horse-power triple-expansion engine. A hydraulic dredge
consists mainly of a centrifugal pump with its driving engine and
boiler, and hoisting machinery for handling suction pipe and boat; the
pump in operation creates a strong suction flow in the suction pipe,
sufficient to pick up the material and draw it into the pump, from
which it is again delivered through the discharge pipe any distance
to point of delivery, and can at same time be elevated to reasonable
heights. Sand, mud, silt, etc., are readily picked up by the suction
force only, but where material is packed it must first be agitated.
TABLE.
=========+==========+==========+===================+===========+=============
Diameter |Capacity, |Elevations|Size Steam Cylinder| Size | Size
Discharge| Gallons | in Feet +---------+---------+Steam Pipe,|Exhaust Pipe,
Opening |per Minute| up to |Diameter | Stroke | Inches | Inches
---------+----------+----------+---------+---------+-----------+-------------
2 | 120 | 25 | 3 | 3 | 3/4 | 1
2-1/2 | 180 | 25 | 3 | 3 | 3/4 | 1
3 | 260 | 25 | 3 | 3 | 3/4 | 1
4 | 470 | 25 | 4 | 4 | 3/4 | 1
5 | 735 | 25 | 5 | 5 | 1 | 1-1/4
6 | 1050 | 30 | 5 | 5 | 1 | 1-1/4
8 | 2000 | 30 | 8 | 8 | 1-1/2 | 2-1/2
10 | 3000 | 10 | 6 | 6 | 1-1/4 | 1-1/2
10# | 3000 | 40 | 12 | 10 | 2-1/2 | 3
12 | 4200 | 20 | 9 | 9 | 2 | 3
12 | 4200 | 30 | 12 | 10 | 2-1/2 | 3
12# | 4200 | 40 | 14 | 12 | 3 | 3-1/2
15 | 7000 | 30 | 14 | 14 | 3 | 4
15* | 7000 | 22 | 12 | 10 | 2-1/2 | 3
18 | 10000 | 30 | 15 | 10 | 4 | 5
18* | 10000 | 20 | 12 | 12 | | 3-1/2
20 | 12000 | 20 | 14 | 14 | 3 |
---------+----------+----------+---------+---------+-----------+-------------
* Low-Lift Pumps. # Special High-Lift Pumps.
The steam shovel, bucket or elevator dredge will do efficient service
in raising material, but none are capable of delivering the material
except within a very short radius of the dredging operation. The
centrifugal dredge not only raises the material, but also delivers it
at the place wanted, at one operation. _Besides, it is practically
impossible to build any other type_ with the enormous capacity that
some hydraulic dredges have.
[Illustration: FIG. 499.]
Fig. 499 is a perspective view of a centrifugal vertical pump of
_the submerged type_. This pump is used largely by contractors in
excavations and coffer dam work and for keeping pits drained.
A double suction centrifugal pump, _driven directly by a steam engine_,
is shown in Fig. 497; these are generally and very satisfactorily used
for circulating water through surface condensers and the cooling pipes
in refrigerating systems. The engine and pump thus combined occupy
small floor space and consequently little masonry is required for a
foundation.
[Illustration: FIG. 500.]
_The Buffalo centrifugal pump_ is shown in Fig. 500. These are built
by the Buffalo Forge Co. in two types, viz., the submerged and the
suction; the latter is the one shown in the cut. The suction type is
employed for pumping from mines, pits, etc., and all places where the
supply will not allow of a horizontal pump to be used, or in others
where the supply is either below the pump, _or sometimes above and
at other times below_. This type possesses merit above the submerged
design in that it will work equally well, when set either above or
below the liquid to be pumped.
_Multi-stage centrifugal pumps._ Experience has demonstrated that by
placing several pumps together and discharging from one into the other,
water can be delivered to almost any height. For a long time after the
introduction of centrifugal pumps, it was supposed that about sixty
feet was the limit for their economical working, owing to the high
speed at which they had to be run to accomplish the results desired.
It was a discovery of importance, that _by coupling two or more pumps
in series_, so that each pump worked against only a part of the total
delivery head, water could easily be raised to even two thousand
feet or any reasonably high head with satisfactory efficiency. Pumps
connected in this way will throw more water at a given speed than when
operated separately, and are therefore attended by less wear and tear.
[Illustration: FIG. 501.]
Pumps worked in series are built compound, triple or quadruple as
required by service either belt driven or directly connected to
engines. Owing to the fact that they have no valves or absolutely
close-parts, they are able to pump muddy or gritty water with sand in
suspension, and are, therefore, especially in the vertical type, the
only ones that can be successfully used for draining deep mines.
Fig. 501 is designed to illustrate _a four stage centrifugal pump_, or
a quadruple compound pump capable of lifting water 250 feet.
[Illustration: FIG. 502.]
_Explanation of diagram page 225._ In determining the requirements best
suited as regards rotation of shaft and connection with the suction and
discharge pipes, in installing a pump, the figure 502, will be found
a convenience. It is important to run the most direct pipes with the
least number of elbows or bends.
The diagram relates particularly to the centrifugal pumps made by
the Morris Machine Works of Baldwinsville, N. Y.; the principle is,
however, of general application. In making use of the diagram each
number represents a particular design. See Note.
_How to determine right-or left-hand pumps._ If, when standing at the
suction end of pump, looking over the pump shell toward the pulley, the
top of the shaft revolves from right to left, or _against the hands of
clock_, the pump is _right-hand_, and from left to right, or _with the
hands of clock_, it is _left-hand_.
_Directions for erecting and running centrifugal pumps._ Place the pump
as near suction water as possible, and limit suction lift to 20 feet or
25 feet.
Erect the pump so that the pump shaft is level; in bolting to
foundation be careful that the frame is not sprung. See that the
bearings are clean and well oiled. The suction pipe and stuffing-boxes
must be air-tight.
Never use pipes smaller than those represented by the flanges on the
pump; avoid elbows or bends as much as possible; if discharging long
distances, use pipes one or two sizes larger than ordinary.
Whether a foot valve is used or not, a strainer should be attached
to the suction pipe to prevent large substances from entering, that
might choke or clog the pump, but be careful that suction area is not
contracted.
NOTE.—In viewing diagrams on page 225 you are supposed to stand at
the outer half of pump shell looking over pump towards the pulley or
engine, if directly connected. _The pump can be swiveled around the
frame_, so that, for instance, if you order pump per diagram No. 50,
it can after receipt be made Nos. 51, 52 or 53.
_Run the pump in proper direction, as indicated by arrows cast on the
pump shell._
If the combined length of suction and discharge pipe is more than 50
feet, the speed must be increased to overcome friction.
Before starting, prime the pump so that suction pipe and pump are
filled with water.
Warm water can only be raised by suction to moderate heights, and if
very hot it must flow to the pump. To prevent freezing in cold weather,
drain by unscrewing plug provided in the bottom of the pump shell.
Sometimes a pump when first started will deliver a good stream of
water, which gradually diminishes in volume until it stops entirely.
One reason for this is a leak in suction pipes or stuffing-box of
pump, or, when suction primer is used, in the hand pump stuffing-box.
Another reason might be that the pump lowers the suction supply,
thus increasing the lift until there is not sufficient speed for
the elevation. If the pump works indifferently, delivering a stream
obviously too small, it is generally because the pump was not properly
primed and some air remains in the top part of pump shell. Unless
primed by steam ejector, the pet cock or plug found on top of pump
shell should always be open while priming, and the pump must not be
started until water flows out of same.
NOTE.—“One feature or fact in centrifugal pumping that is overlooked
or not known to many makers, is that water will not enter a pump when
the impeller vanes sweep over the inlet way and are driven at high
speed. To illustrate this, one can not thrust a cane or lath through
the spokes of a rapidly revolving wheel. European centrifugal pumps
with their small impellers and consequent high speed of rotation, are
especially liable to this repelling action, and very often are wholly
inefficient from this cause. One maker who claims a high duty for
his pumps, attaches a screw at the sides of the impeller to coax the
water into the pump, and the idea is a good one if the difficulty is
not otherwise provided for. In this way a pump can be made of smaller
diameter for a given duty, but it is commonly inferior to a larger
one for the same work.”—_Industries._
A pump with horizontal top discharge and short length of discharge
pipe is sometimes difficult to start, especially if suction lift is
high, owing to the fact that the water is thrown out of the pump shell
before the water in the suction pipe has got fairly started, thus
allowing air to rush back into the pump. If the pump is to work under
this condition, it is better to use a pump with a vertical discharge
and deliver through an elbow, or else lead the discharge pipe upward
for a short distance so as to keep a slight pressure, or head on the
pump, and after priming as high as possible start quickly.
Generally nothing is gained by running a pump above the proper speed
required for a given elevation.
In addition to what is said in connection with the priming device
illustrated on page 218, numerous other methods have been adopted to
suit pumps of various designs. The accompanying engravings represent
those largely used.
Fig. 1 illustrates a multi-stage turbine pump with ejector for priming.
The ejector is connected to the highest point on the pump casing, and
either steam, air or water under pressure may be employed in it to
produce a vacuum.
Fig. 2 shows an auxiliary hand pump mounted on top of the discharge
casing. When the pump is ready to start, the gate valve on the
discharge is closed, and by operating the hand pump a vacuum is
produced and water drawn in, filling the suction pipe and casing.
The method of priming shown in Fig. 3 may be resorted to where a foot
valve is used on the suction pipe. Water is allowed to run into the
pump until it reaches the discharge flange, when the supply is shut
off, and the pump may be started.
After the pump has been properly primed, it should be started before
the gate valve on the discharge is opened. When full speed is reached,
the discharge gate may be slowly opened, and the pump will perform its
work.
NOTE.—_The Worthington centrifugal pumps_ are divided into three
classes, viz.: _Conoidal_, _Volute_ _and Turbine_.
_The Conoidal Centrifugals_ (_named from the cone-shaped impeller_)
are designed especially for low lifts and large deliveries and are
adapted to irrigation work, the handling of sewage and similar
purposes. They are comparatively inexpensive and operate at high
rotative speeds, making possible direct connection to electric
motors. _For heads up to 30 feet_ they are unexcelled in the pumping
field.
_The Volute Centrifugals_ (illustrated on page 232) are built for
medium lifts, but for all capacities. Since they run at moderate
speeds, diffusion vanes are not needed, but the volute casing has
been carefully designed to obtain high efficiency and 86% has been
shown under test. These pumps are recommended _for heads up to 70
feet_, although they will safely withstand 150 feet.
It is always best to use a foot valve in connection with centrifugal
pumps where the lift is more than three to four feet, and even under
these low lifts where long suction pipes are used to conduct water
long distances, foot valves should always be used to keep the pump and
suction pipe charged.
[Illustration: FIGS. 1, 2 AND 3.]
[Illustration: FIG. 503.]
TURBINE PUMPS.
_The Turbine Pump_ is suited to very high lifts, _even exceeding 2,000
feet_. An admirable example of this class of pumps is described in the
following paragraphs:
The Worthington turbine pump has been developed by a long series of
experiments. _The diffusion vanes_ which form the distinguishing
feature, take the place of the usual whirlpool chamber and assist in
bringing the water to rest without internal commotion or shock. They
correspond in function to _the guide vanes of turbine water-wheels_.
One of the difficulties presented by high-lift centrifugal pumps has
been the great peripheral speed required when only a single impeller
is employed. _This has been overcome by mounting a number of discs or
impellers, each operating in a separate chamber, upon a single shaft
and passing the water through the impeller chambers in succession._ The
lift can thus be multiplied three, four or five times, while the number
of revolutions is kept within bounds. It has been demonstrated that on
the same work and within reasonable limits, multi-stage centrifugals
are more efficient than single-stage pumps, the increased efficiency
being due to _a decrease in the frictional losses_ coincident with the
reduced peripheral speed of the impeller.
It is well known that the turbine water wheel was perfected less by
mathematical processes than by intelligent cut and try methods. It has
been the same with the turbine pump, whereby the vanes and passages
have been shaped and tested by practical experiments, followed in each
case by comparison of results. The constant aim has been to avoid
eddies and secure a favorable discharge of the water.
NOTE.—At the St. Louis World’s Exposition three of the 36-inch
Worthington turbine pumps, each of a capacity of 35,000 gallons per
minute against 160 feet head, supplied the Grand Cascade.
[Illustration: FIG. 504.]
The ills. on the opposite page (Fig. 503), which represents in outline
a Worthington turbine pump, indicates the difficulty of exactly and
mathematically designing such a mechanism. In the system shown only
suction and discharge pipes are employed, the water entering axially
and issuing radially. _The impellers_ remain in perfect longitudinal
balance regardless of their number or the head against which the
pump is operated, this balancing of the impeller being secured by an
ingenious system of “triple vanes.”
_The diffusion vanes._ In the Worthington turbine pump the efficient
conversion of energy is assured by an original system of diffusion
vanes disposed in the throat opening between the periphery of the
impeller and the annular casing, in much the same manner that guide
vanes are placed in a reaction turbine water-wheel. These vanes form
tangential, expanding ducts from which the fluid emerges at about the
velocity existing in the chamber. They also eliminate all drag and
friction between the periphery of the rapidly revolving impeller and
the slowly moving water in the discharge chamber.
The turbine pump has created an entirely new field of application for
centrifugal pumps, embracing mine drainage, water-works, and numerous
other services where rotary pumps are desirable but have not been
employed, owing to their former limited efficiency at high heads.
As a sinking or station pump for mine service, the turbine pump is
ideal. There are no valves, guards or springs, no reciprocating parts,
and, most important of all, there is no contact surface in the machine
except the shaft and its bearings. The design is such that parts
subjected to the action of mine water may be made of acid-resisting
metal, and, when desired, lead-lined.
NOTE.—The space occupied by the turbine pump is less than one-third
of that required by a reciprocating pump of equal capacity, and
the first cost, including the motor for driving, is only about
one-half. Since there are no rubbing surfaces exposed to the water,
the pump will run for years without renewal or repairs. In case
of accident, the parts are so few and the construction so simple
that any part of the machine can be replaced in less than one hour.
The cost of attendance is reduced to the minimum, since the only
necessary attention is to see that the pumps and motors are properly
lubricated. The simplicity and reliability of the centrifugal pump
make it especially suitable for isolated stations.
[Illustration: FIG. 505.]
[Illustration: FIG. 506.]
[Illustration: FIG. 507.—See page 241.]
Turbine pumps of excellent design (Fig. 507) of high efficiency are
built by the Byron Jackson Machine Works of San Francisco, California.
The operating elements of these pumps are rotating impellers containing
spirally-curved water passages, and fixed guide passage between
successive impellers. The water enters the passages of each impeller
_at the center_ and by the rotation is forced out into a collecting
chamber surrounding the periphery of the impeller. The ducts which
lead the water from there back to the center of the next impeller are
suitably curved to act as guide passages, similar in action to the
guide buckets of a turbine. The water then enters the next impeller
parallel with the shaft, its rotary motion having been transformed by
the guide passages into rectilinear motion.
Fig. 509, a drawing of a vertical pump in section, shows the relative
arrangement of impellers (marked A) and guide passages (B). This
pump has the suction entrance at the top; the discharge leaves the
collecting chamber of the last (lowest) impeller tangent to the circle.
The shaft rests in a thrust bearing at the top, and is further held by
bearings formed in the successive sections of the case. At the bottom
it is provided with a special balancing arrangement, described here
after.
[Illustration: FIG. 508.]
Each impeller, where it joins the guide passages of the preceding
case section, is fitted into the case so as to form as tight a joint
as possible without introducing any great frictional resistance to
rotation. With the exception of the entrance opening, the external
surface of the impeller is exposed to the delivery pressure, so that
there is a resultant upward pressure on each impeller, equal to the
area of its entrance multiplied by the difference between the entrance
and discharge pressures of that stage. If all the impellers are alike,
the total upward thrust is equal to the product of entrance area
multiplied by the total head on the pump. The pumps are so proportioned
that this upward thrust slightly exceeds the weight of the rotating
portion, consisting of impellers and shaft. _The excess of upward
pressure, however, is relieved by the balancing device located at the
lower end of the shaft, with the result that the_ _rotating part is
precisely balanced, thus relieving the thrust bearing of all load while
the pump is running._
The balancing device referred to consists of two chambers, C and D,
formed centrally in the bottom of the lowest section of the pump case.
The large chamber, C, encloses a projecting hub, E, on the lower
surface of the impeller. This hub of course rotates with the impeller,
and the joint between the hub and the walls of the chamber is,
therefore, loose enough to allow water from the delivery side of the
last impeller to leak into chamber, C, and establish the full discharge
pressure in that chamber. The small lower chamber, D, contains a plug,
H, which may be adjusted endways by means of screws. The forward end of
this plug fits closely into a recess in the face of the hub, E, which
recess, communicates, by way of the hollow central part of the hub and
the passage, _g_, with the entrance side of the last impeller.
The action of the device is as follows: when chamber, C, becomes
filled with water, or rather when leakage through the joint around the
tube, E, has raised the pressure in the chamber, C, to the delivery
pressure, the total upward pressure on the impellers is greater than
the total weight of the rotating part of the pump. The rotating element
is therefore lifted until the recess in hub, E, is raised clear of
the plug, H. In this position the pressure in chamber, C, is relieved
through the passage, _g_, with the result that the rotating element
again settles down over the adjusting plug, H. As this action tends to
recur, a position of equilibrium is established near the point where
the plug just enters the recess in the hub, E. The precise position
of this point may be altered by the adjusting screws of the plug, H,
thereby adjusting the endwise position of the impellers in the casing.
When the pump is not in operation, of course the upward pressure of the
water does not act, and the weight of the rotating part must be carried
by the thrust bearing.
[Illustration: FIG. 509.]
When these pumps are built with horizontal shaft, the unbalanced
pressure which is thus turned to account in the vertical pump
becomes harmful and must be avoided. The arrangement by which this
is accomplished is shown in Fig. 510, where the letters, A and B,
designate respectively the impellers and the guide passages as before.
The rear of each impeller, that is, the side opposite the entrance
opening, bears a short annular projection, S, fitting within a similar
ring, _t_, projecting from the casing. The circular chamber formed
by these two rings communicates, through holes, V, in the web of the
impeller, with the entrance side of the impeller. The chamber being
slightly larger than the entrance opening of the impeller, it serves
to eliminate all thrust on the impeller in the direction of the
suction (since the remainder of the external surface is exposed to
the discharge pressure), and produces instead a small thrust directed
toward the discharge end.
This small resultant thrust is taken up by a balancing device at the
end of the shaft precisely similar to that used in the vertical type
of pump, as previously described. The balancing action thus secured
serves to fix the endwise position of the rotating part; moreover, it
affords sufficient margin to compensate for longitudinal thrusts which
may result from causes such as slightly non-central position of the
impellers in their casing.
Pumps of this design are built for heads of from 100 to 2,000 ft., the
number of separate impellers or “stages” being properly proportioned to
the head. _About 100 to 250 ft. head per stage_ appears to be allowed.
A high efficiency of working, from 70 to 80%, is said to be realized.
_The horizontal two-stage pump_ shown in Fig. 507 is one built for the
water-works of the city of Stockton, Cal., to deliver 1,500 gallons
per minute against a head of 140 ft., at 690 r. p. m. It is driven by
a 75-HP. induction motor of the Westinghouse Electric & Mfg. Co. type,
of Pittsburg, Pa. Pump and motor are mounted on a common base, and
their shafts are solidly coupled. This pump was guaranteed to have an
efficiency of at least 75%, but we are informed by the manufacturers
that the official test showed it to have an efficiency of 82%.
_The vertical pump of four stages_, shown in Fig. 508, has a discharge
capacity of 450 gallons per minute and delivers against a head of 500
ft. The same type of pump, however, will work against heads up to 800
ft. The mounting of the pump in the present instance is at the bottom
of a 200-ft. pit; the pump shaft leads vertically to the surface, where
it is driven by belt. A closely similar installation has been made,
where two vertical three-stage pumps operate under a head of 310 ft.
The pumps are located in a 30-ft. pit, and their shafts are extended
to the surface, where they carry each a 200-HP. induction motor mounted
directly on the shaft. The balancing action of the pump was in this
case designed to be sufficient to carry the entire weight of the
rotating part, that is, motor, shaft and pump impellers.
[Illustration: FIG. 510.]
INJECTORS
AND
EJECTORS
[Illustration: FIG. 511.—See page 251.]
[Illustration: FIG. 512.—See page 251.]
THE INJECTOR.
_This consists, in its most simple form, of a steam nozzle, the end of
which extends somewhat into the second nozzle, called the combining or
mixing nozzle; this connects with, or rather terminates in, a third
nozzle or tube, termed “the forcer.”_ At the end of the _combining
tube_, and before entering the forcer, is an opening connecting the
interior of the nozzle at this point with the surrounding space. This
space is connected with the outside air through a check valve, opening
outward in the automatic injectors, and by a valve termed the overflow
valve. The injector nozzles are tubes, with ends trumpet mouthed to
receive and deliver the fluids with the least possible loss by friction
and eddies.
As a thermodynamical machine, the injector is nearly perfect, since all
the heat received by it is returned to the boiler, except a very small
part which is lost by radiation; consequently its thermal efficiency
should be in every case nearly 100 per cent.
NOTE.—The operation of the injector is based on the fact, first
demonstrated by Giffard, that the motion imparted by a jet of steam
to a surrounding column of water is sufficient to force it into the
boiler from which the steam was taken, and, indeed, into a boiler
working at a higher pressure. The steam escaping from under pressure
has, in fact, a much higher velocity than water would have under
the same pressure and condition. The rate of speed at which steam
travels—taking it at an average boiler pressure of sixty pounds—when
discharged into the atmosphere, is about 1,700 feet per second. When
discharged with the full velocity developed by the boiler pressure
through a pipe, say an inch in diameter, the steam encounters the
water in the combining chamber. It is immediately condensed and
its bulk will be reduced say 1,000 times, but its velocity remains
practically undiminished. Uniting with the body of water in the
combining tube, it imparts to it a large share of its speed, and the
body of water thus set in motion, operating against a comparatively
small area of boiler pressure, is able to overcome it and flow into
the boiler. The weight of the water to which steam imparts its
velocity gives it a momentum that is greater in the small area in
which its force is exerted than the boiler pressure, although its
force has actually been derived from the boiler pressure itself.
[Illustration: FIG. 513.—See page 252.]
[Illustration: FIG. 514.—See page 251.] All injectors are similar in
their operation. They are designed to bring a jet of live steam from
the boiler in contact with a jet of water so as to cause it to flow
continuously in the direction taken by the steam, the velocity of which
it in part assumes, back into the boiler and against its own pressure.
There are three distinct types of live steam injectors, the “simple
fixed nozzle,” the “adjustable nozzle,” and the “double.” The first has
one steam and one water nozzle which are fixed in position but are so
proportioned as to yield good results. There is a steam pressure for
every instrument of this type at which it will give a maximum delivery,
greater than the maximum delivery for any other steam pressure either
higher or lower.
The second type has but one set of nozzles, but they can be so adjusted
relative to each other as to produce the best results throughout a long
range of action; that is to say, it so adjusts itself that its maximum
delivery continually increases with the increase of steam pressure. The
third type, double injectors, are those in which the delivery from one
injector is made the supply of a second, and they will handle water at
a somewhat higher temperature than single ones with fixed nozzles. The
double injector makes use of two sets of nozzles, the “_lifter_” and
“_forcer_.” The lifter draws the water from the reservoir and delivers
it to the forcer, which sends it into the boiler. All double injectors
have fixed nozzles.
The action of the injector is as follows: Steam being turned on, it
rushes with great velocity through the steam nozzle into and through
the combining tube. This action causes air to flow from the suction
pipe, which is connected to the combining tube, with the result that
more or less vacuum is formed, thus inducing a flow of water.
NOTE.—_The motive force of the injector is found in the heat received
from the steam._ The steam is condensed and surrenders its latent
heat and some of its sensible heat. The energy so given up by each
pound of steam amounts to about 900 thermal units, each of which
is equivalent to a mechanical force of 778 foot pounds. This would
be sufficient to raise a great many pounds of water against a very
great pressure could it be so applied, but a large portion of it
is used simply to heat the water raised by the injector. The above
explanation will apply to every injector in the market, but ingenious
modifications of the principles of construction have been devised in
order to meet a variety of requirements.
[Illustration: FIG. 515.—See page 252.]
[Illustration: FIG. 516.—See page 252.]
After the water commences to flow into the injector it receives motion
from the jet of steam; it absorbs heat from the steam and finally
condenses it, and thereafter moves on through the forcer tube simply
as a stream of water, at a low velocity compared with that of the
steam. At the beginning of the forcer tube, it is subjected only to
atmospheric pressure, but from this point the pressure increases and
the water moves forward under a diminished velocity.
That the condensation of the steam is necessary to complete the process
will be evident, for if the steam were not condensed in the combining
chamber, it would remain a light elastic body and, though moving at
high speed, would have a low degree of energy.
Some injectors are given special names by their makers, such as
ejectors and inspirators, but the term injectors is the general name
covering the principle upon which all these devices act. The exhaust
steam injector is a type different from any of the above-named, in that
it uses the exhaust steam from a non-condensing engine. Exhaust steam
represents fourteen and seven-tenths (14.7) pounds of work, and when
the steam entering the injector is condensed the water is forced into
the boiler upon the same general principle as in all injectors.
The injector can be, and frequently is, used as a pump to raise water
from one level to another. It has been used as an air compressor,
exhauster and also for receiving the exhaust from a steam engine,
taking the place, in that case of both condenser and air pump.
The injector is not an economical device, but it is simple and
convenient; it occupies a very small space, is not expensive and
entirely free from severe strains on its durability; moreover, where a
number of boilers are used in one establishment, it is very convenient
to have the feeding arrangements separate, so that each boiler may be a
complete generating system in itself and independent of its neighbors.
_The following text_ is intended to describe the instruments
illustrated on pages 244, 246, 248 and 250.
[Illustration: FIG. 517.]
[Illustration: FIG. 518.]
_The “Manhattan” automatic injector_ is shown in perspective and
outline upon page 244. This instrument is made by Messrs. Schaeffer &
Budenberg of New York City.
This injector is designed for portable and semi-portable engines and
boilers, and is also adapted for stationary boilers _requiring no high
lift_. Its main features are simplicity and positive automatic action.
It works under pressures ranging from 30 to 150 lbs., either lifting or
non-lifting.
The letters in the outline cut refer to the parts:
_a._ Steam Nozzle.
_b._ Combining Nozzle with Flap.
_c._ Delivery Tube.
_d._ Screw Cap.
_e._ Cap Screw for Overflow.
_f._ Overflow Valve.
_g._ Tail Pipe.
_h._ Tail Pipe Nut.
_The “Peerless” automatic injector_ is shown on page 246. This is, in
effect, the same instrument as the “Manhattan” except it has a steam
spindle with handle to regulate the flow of steam. See figure 514.
Two classes of Peerless injectors are made, viz.:
Class A—for high pressures ranging from 50 to 200 pounds.
„ B— „ low „ „ „ 20 to 80 „
and they are stamped accordingly.
They are adapted for any service requiring the lifting of water.
Class A is made for lifts up to 12 feet.
„ B „ „ „ 8 „
but if so ordered, they can be arranged for higher lifts. They may also
be used as non-lifting injectors.
The temperatures of feed water taken by these injectors, if non-lifting
or at a low lift, can be as follows:
PRESSURE.
35 to 45 50 to 85 90 105 lbs.
TEMPERATURE.
144 to 136 133 to 130 129 122° F.
PRESSURE.
120 135 150 lbs.
TEMPERATURE.
118 to 113 109 to 105 104 to 100° F.
The spindle acts as a valve for the steam inlet; an extra seam valve is
therefore not absolutely required, but recommended for convenience of
detachment.
The letters in Figs. 520-533, page 254, relate to the names of “the
parts” of the Peerless injector.
_a._ Steam Nozzle.
_b._ Combining Nozzle with Flap.
_c._ Delivery Tube.
_e._ Cap Screw for Overflow.
_f._ Overflow Valve.
_g._ Tail Pipe.
_h._ Tail Pipe Nut.
_j._ Screw Plug with Stuffing-Box.
_k._ Follower Nut on Plug j.
_l._ Packing Sleeve to j.
_m._ Steam Spindle.
_n._ Crank to Spindle m.
_o._ Screw Nut to Spindle m.
_p._ Handle to Crank n.
_The Monitor injector_, Fig. 513, page 246, was designed originally for
locomotive work. It consists mainly of two parts, viz., 1, the lifting
device which raises the water into the injector and, 2, the forcing
device which “picks up” the water and causes it to flow into the boiler.
_The Metropolitan double tube injector_ is shown in the two figures on
page 248.
These are made by the Hayden & Derby Mfg. Co. This instrument is of
the double-tube design and in that particular resembles the Korting
injector described on page 264. Both the lifting and forcing, as well
as the overflow valves are controlled by one handle.
_The Metropolitan single tube injector_ is represented by the Figs. 517
and 518, page 250. The internal parts of this injector, as may be seen
from the sectional engraving, are stationary. The steam is regulated
by the handle, K, which is attached to the stem, M; the water supply
adjusts itself automatically.
_The capacity of the leading injectors_ is nearly the same under
similar working conditions as represented by the following
TABLE.
=============+=================+=================
Size of Pipe |Gallons per Hour.|Gallons per Hour.
Connections. | Maximum. | Minimum.
-------------+-----------------+-----------------
3/8 inch. | 85 | 50
1/2 „ | 165 | 75
3/4 „ | 350 | 130
1 „ | 580 | 325
1-1/4 „ | 900 | 425
1-1/2 „ | 1750 | 750
2 „ | 2850 | 1150
-------------+-----------------+-----------------
The figure below shows how the connections or piping should be made in
attaching the Manhattan and Peerless injectors.
The dotted lines indicating pipe and fittings in connection with the
suction represent the way the water supply is to be received from a
tank located above the level of the injector.
[Illustration: FIG. 519.]
The makers of these two instruments have kindly furnished the following
general rules to govern their connection with steam supply:
1. _Place injector in a horizontal position._ (See illustrations 512
and 514.) The flap nozzle must in all cases open upward in direction of
air valve. In taking injectors apart be careful to replace it in that
position.
2. _Take steam from the highest part of boiler_; never connect to pipes
furnishing steam for other purposes.
3. _Have all joints perfectly tight_, especially the suction pipe, as
no injector will lift water unless atmospheric air is excluded.
4. _Have all pipes thoroughly cleaned_ from red or white lead and scale
before the injector is connected; it will save trouble afterwards.
5. _All pipes must be of the same or larger diameter_ than the
corresponding parts of injector.
6. _Avoid all short bends_, and have all pipes as short and straight as
practicable.
7. _Use a strainer at the end_ of suction pipe; the holes in the
strainer should be small, but _their total area larger_ than the area
of the supply pipe.
8. _Insert stop valves in suction, steam and delivery pipes_, to
facilitate disconnection in cleaning injector and check valve in
delivery pipe.
[Illustration: FIGS. 520-533.]
9. _Have valve stems packed well_; they often leak.
10. _To remove incrustations_ caused by water containing lime or other
impurities, place parts for a reasonable time in a bath of mineral oil
or diluted muriatic acid consisting of 4 parts of water to 1 part of
acid.
NOTE.—The lettered parts shown above apply to both the “Manhattan”
and the “Peerless” injectors. See page 252 for the names of the
parts corresponding with the letters.
_The exhaust steam injector_ utilizes the escaping vapor from the
engine cylinder, hence the saving in fuel and water is very marked
where certain conditions are favorable.
It condenses by means of the smallest possible quantity of cold water
the largest possible quantity of exhaust steam and _puts it into the
boiler without the aid of any other power than the exhaust steam
itself_. It can be attached to any class of non-condensing engine, and
its use increases the power both of the engine and boilers.
[Illustration: FIGS. 534 AND 535.]
It is worked by waste steam, just as ordinary injectors are worked by
live steam from the boiler.
The first cost and subsequent wear and tear of pumps are avoided. The
power required to work pumps, of whatever construction, is saved: the
exhaust injector doing the same work by the condensation of waste steam.
The waste steam, in passing through the injector, heats the feed-water
to a temperature of about 190° F. The condensation in the injector of
so large a quantity of waste steam reduces back pressure considerably,
and necessarily increases the power of the engine.
It is not uncommon for these injectors to form a vacuum of a half-inch
of mercury within the exhaust pipe, which of course helps the engine to
that extent.
[Illustration: FIG. 536.—See page 260.]
These injectors work with great success on stationary engines and
boilers, also on steamers, tugs, dredges, etc., as their operation
during the roughest weather is not affected by the motion of the
vessel.
_The high pressure_ exhaust steam injector is shown in Figs. 537 and
538—the last being an outline exhibiting the internal arrangement of
the instrument: these injectors are made to work at all pressures up to
and not exceeding 150 lbs. to the square inch.
[Illustration: FIG. 537 AND 538.]
_The high pressure exhaust steam injector_ is worked _by waste steam
up to 75 lbs. pressure only_, and a little live steam is introduced at
the top of the injector to force water against pressures higher than 75
lbs. It will be noticed from sectional cut that _the live steam does
not come in contact with the water until after the exhaust steam has
been condensed and has done its work_. The _exhaust steam alone_ gives
an impetus to the water equal to 75 lbs.; it also _heats_ it up to
about 190° F. Its advantages are the same as those of the plain exhaust
injector, the heat of the small jet of live steam which is used to
overcome the excessive pressure being brought back into the boiler.
It raises the temperature of feed-water up to 90° Fahr. if working
against a pressure of 105 lbs., and up to 86° Fahr. against 120 lbs.
boiler pressure. It is regulated in the same manner as the plain
exhaust steam injector.
It is not necessary _to use live steam while working against any
pressure below 75 lbs., when exhaust steam alone will suffice_.
Fig. 539 represents the piping of the high pressure exhaust steam
injector, the operation of which is described in the following
paragraphs:
_This injector can be worked under various conditions._
1. If boiler pressure does not exceed 75 lbs. per square inch, exhaust
steam only is required. In this case steam is admitted by valve A.
[Illustration: FIG. 539.]
2. For pressures exceeding 75 lbs. exhaust steam is admitted as before,
also a little live steam, slowly, by valve C.
3. If engine is not running, live steam is gradually admitted by valve
B, so that it may expand in pipe F. In case of high boiler pressure
additional live steam is introduced by valve C.
_To start this injector._
1. Open steam valves as described.
2. Then open water valve.
3. Regulate water valve, and, if necessary, screw up or down nut R at
the lower end of injector until overflow ceases.
If desired, _a gauge indicating both pressure and vacuum_ (a compound
gauge) can be furnished with exhaust steam injectors.
TABLE OF SIZES.—PIPE CONNECTIONS.
==========+==========+==============================================
| | INSIDE DIAMETER OF PIPES.
| Delivery +-----------+------------+----------+----------
SIZE OF |in Gallons| Branch |Water Supply|Feed-Water| Live
INJECTOR | per Hour |for Exhaust| Pipe | Pipe | Steam
----------+----------+-----------+------------+----------+----------
No. 2 | 60 | 1-1/4 inch| 1/2 inch| 3/4 inch| 1/4 inch
„ 2-1/2 | 120 | 1-1/2 „ | 3/4 „ |1 „ | 1/4 „
„ 3 | 175 | 1-1/2 „ | 3/4 „ |1 „ | 1/4 „
„ 4 | 300 | 2 „ | 1 „ |1-1/4 „ | 3/8 „
„ 5 | 480 | 2-1/2 „ | 1 „ |1-1/4 „ | 3/8 „
„ 6 | 680 | 2-1/2 „ | 1-1/4 „ |1-1/2 „ | 3/8 „
„ 7 | 920 | 3 „ | 1-1/4 „ |1-1/2 „ | 1/2 „
„ 8 | 1200 | 3-1/2 „ | 1-1/2 „ |2 „ | 1/2 „
„ 9 | 1550 | 4 „ | 2 „ |2-1/2 „ | 1/2 „
„ 10 | 1920 | 4-1/2 „ | 2 „ |2-1/2 „ | 3/4 „
„ 12 | 2800 | 6 „ | 2-1/2 „ |3 „ | 3/4 „
„ 20 | 10000 |10 „ | 4 „ |4-1/2 „ |1-1/4 „
| |(OR LARGER)| | |
----------+----------+-----------+------------+----------+----------
_The ejector is a low lift pump_; it works on the same principle as
that of an injector. It has less parts than the latter and is less
expensive. The following table applies to ejectors.
TABLE.
=======+===========+===========+===========+============+==========
| | | | |Capacity
| Discharge | Suction | Steam | Steam jet |per Hour,
Size | Pipe | Pipe | Pipe | Diameter |in Gallons
-------+-----------+-----------+-----------+------------+----------
No. 1 | 1/2 in. | 3/4 in. | 3/8 in. | 11/100 in. | 300
„ 2 | 3/4 „ | 1 „ | 3/8 „ | 15/100 „ | 500
„ 3 | 1 „ | 1-1/4 „ | 1/2 „ | 20/100 „ | 750
„ 4 | 1-1/4 „ | 1-1/2 „ | 1/2 „ | 25/100 „ | 1,200
„ 5 | 1-1/2 „ | 2 „ | 3/4 „ | 30/100 „ | 1,700
„ 6 | 2 „ | 2-1/2 „ | 3/4 „ | 40/100 „ | 3,000
„ 7 | 2-1/2 „ | 3 „ | 1 „ | 50/100 „ | 5,000
„ 8 | 3 „ | 4 „ | 1 „ | 60/100 „ | 7,500
„ 9 | 4 „ | 5 „ | 1-1/4 „ | 80/100 „ | 10,000
„ 10 | 5 „ | 6 „ | 1-1/2 „ | 1 „ | 14,000
-------+-----------+-----------+-----------+------------+----------
[Illustration: FIGS. 540 and 541.]
The accompanying Figs. 540 and 541 represent an ejector with a foot
strainer. The table, page 259, gives an idea of its pipe sizes and
capacities.
_Application of ejectors._ The Fig. 536, page 256, shows two ejectors
applied in different ways. One is mounted _to lift and force water_,
and the other _to force only_; the latter is submerged in the water
to be elevated, and placed in a vertical position to reduce the
condensation of operating steam to a minimum. In both of these examples
of the use of the device it will be noted a strainer is attached to the
suction pipe. The arrows show the direction of the flow of both the
steam and water.
Certain ejectors will not work well when the steam pressure is too
high. In order to work at all the steam must condense as it flows
into the combining tube. Therefore, when the steam pressure is too
high, and the heat is very great, it is difficult to effect complete
condensation; so that for high pressure steam good results can only be
obtained with cool water. It would be well when the feed water is too
warm to permit the ejector to work right, to reduce the pressure, and
consequently the temperature of the steam supply, as low pressure steam
condenses quickly, and therefore can be employed with better results
than high pressure steam.
NOTE.—This instrument is marketed as “Van Duzen’s steam jet pump”
(Cincinnati, Ohio), and credit should be given the makers for the
useful table on page 259.
_For high elevations_ and high temperature of liquids, ejectors should
be submerged from three to six feet; the suction pipe should always be
provided with a strainer and the makers of the instruments recommend
the placing of a check valve in the force pipe to facilitate the
cleaning of the suction pipe by steam, when made necessary through the
raising of impure substances.
_To start the ejector_ open the steam valve slowly until the suction
works satisfactorily, _when full amount of steam should be quickly
admitted_.
[Illustration: FIG. 542.]
[Illustration: FIG. 543.]
[Illustration: FIG. 544.]
_A double tube ejector_ is represented in Fig. 542. This is calculated
to use steam economically by reason of its having two tubes, besides
it is well made and properly proportioned to raise water to high
elevations.
Fig. 543 is a cheaper form of apparatus and is designed to elevate
water to very moderate heights and where a saving of steam is not of so
much consequence as in localities where the price of coal is high.
_The jet pump_ presented in Fig. 544 is another compact form of this
style of ejector and is adapted for its own particular class of work
which is but little known to those unaccustomed to use these appliances.
When working either an injector or ejector from a long lift or with
a long pull through horizontal piping, it takes several minutes to
exhaust the air from the pipe when steam is turned on, resulting in a
considerable waste of steam each time the injector is started. This
waste can be done away with by the use of a foot valve.
[Illustration: FIG. 545.]
[Illustration: FIG. 546.]
[Illustration: FIG. 547.]
_Universal double-tube injector_ (original Korting injector). This
instrument is the combination of two jets (see Figs. 545 and 546);
it is proportioned for extreme temperature and for quick and strong
action, which includes maximum high suction. _The discharge is into
the upper jet_, where the water receives the additional strong impulse
to carry it into the boiler. _The pressure and volume from the lower
jet corresponds to the steam pressure_, and this is as it should be to
answer the requirements of the upper or forcing jet. The varying volume
insures the proper working at high steam pressure as well as at low,
and an increased pressure admits of increased high temperature.
The action of the injector is thus explained; its favorable operation
is due to the double-tube principle; the pieces composing the Korting
injector are shown in the numbered cuts, page 263, and _the names of
the parts_ are given below.
_Number and name of piece._ 1, Body; 2, handle lever; 3, side rods;
4, connecting fork; 5, cross head for shaft; 6, nuts for cross head;
7, starting shaft; 8, nuts; 9, yoke bar; 10, lower steam valve;
11, upper steam valve; 12, lower steam nozzle; 13, upper steam
nozzle; 14, lower water nozzle; 15, upper water nozzle; 16, front
body caps; 17, side body caps; 18, overflow nozzle; 19, check valve
compressor; 20, overflow valve compressor; 21, stuffing-box; 22,
fol. for stuffing-box; 23, nuts for stuffing-box; 24, cross head for
overflow; 25, links for overflow; 26, pin for links; 27, screws; 28,
bell cranks; 29, coupling nuts; 30, pipe unions; 31, spanner wrench;
32, sokt. nozzle wrench; 33, un. for cop. pipe.—Regulator complete
replaces pieces 10 and 16.
TABLE.
===================================================================
|Size of|Steam 50 lbs.|Steam 100 lbs.|Steam 150 lbs.|Size of
Size | Iron +------+------+------+-------+------+-------+ Copper
No. | Pipe. |Gals. | H. P.|Gals. | H. P. |Gals. | H. P. | Pipe.
------+-------+------+------+------+-------+------+-------+--------
00 | 1/8 | 33 | 7 | 48 | 10 | 60 | 12 | 1/4
0 | 1/4 | 83 | 17 | 101 | 20 | 112 | 22 | 3/8
1 | 3/8 | 112 | 23 | 143 | 30 | 180 | 36 | 1/2
2 | 1/2 | 172 | 35 | 210 | 40 | 232 | 46 | 5/8
3 }| |{ 278 | 56 | 338 | 70 | 397 | 80 }|
3-1/2}| 3/4 |{ 398 | 80 | 472 | 95 | 547 | 110 }| 7/8
4 | 1 | 533 | 108 | 622 | 125 | 720 | 150 | 1-1/8
5 } | |{ 675 | 136 | 802 | 160 | 922 | 190 }|
6 } | 1-1/4 |{ 825 | 165 | 990 | 200 | 1125 | 230 }| 1-1/2
7 } | |{1072 | 215 | 1372 | 289 | 1612 | 320 }|
8 } | 1-1/2 |{1388 | 280 | 1800 | 360 | 2115 | 430 }| 1-3/8
9 } | |{1688 | 340 | 2100 | 420 | 2475 | 500 }|
10 } | 2 |{2025 | 400 | 2438 | 500 | 2850 | 570 }| 2-1/4
------+-------+------+------+------+-------+------+-------+--------
NOTE.—The above table relates to the double tube injector.
_The acid syphon pump_, shown in Fig. 548 below, is used by many
chemical works, in lifting their acids and other chemicals to be
conveyed to any part of the building. The machine is made of lead,
encased in an iron shell for strength, and fitted with a platinum steam
nozzle to give that part durability.
This device is named a syphon pump because it becomes a _syphon_ by
turning down the delivery pipe and making that end longer than the
suction end. The apparatus, shaded in the figure, is really a jet pump
and it is simply used to operate the syphon, _i.e._, by turning on the
steam the acid will flow through the syphon. At this point the steam
should be shut off and the flow of acid will continue.
[Illustration: FIG. 548.]
_Noiseless Water Heater._ This instrument, Fig. 549, is used for
warming of liquids; it avoids the noise that is otherwise caused by the
action of steam led for that purpose direct into cold liquids.
In operation, the liquid is drawn through the holes in body and
discharged through shank, causing a circulation of the liquid in tank.
TABLE OF DIMENSIONS.
================================+=====+=====+=====+=====+=====+====
Number of Noiseless Water Heater| 3 | 4 | 5 | 6 | 7 | 8
--------------------------------+-----+-----+-----+-----+-----+----
Diameter of Steam Pipe, inch | 3/4 | 1 |1-1/4|1-1/2|1-1/2| 2
--------------------------------+-----+-----+-----+-----+-----+----
[Illustration: FIG. 549.]
_Water Pressure Ejector._ This instrument, Fig. 550, is worked by water
pressure and used to advantage in excavations, cellars, etc., where
water pressure can be had and the required elevation does not exceed
12 feet. It has to be inserted into the water pressure pipe in such
a manner that it will be entirely covered by the water to be raised.
It will raise double the quantity of water which it obtains from the
pressure pipe, _i.e._, it will deliver two gallons for every one it
receives from the pressure pipe.
[Illustration: FIG. 550.]
TABLE OF DIMENSIONS.
==================================+=====+=====+=====
Number of Water Pressure Ejector | 1 | 2 | 3
----------------------------------+-----+-----+-----
Capacity, gallons per hour | 375 | 600 |1,275
Size of Water Pressure Pipe, inch | 1/2 | 3/4 | 1
Size of Delivery Pipe, inch | 1 |1-1/2| 2
----------------------------------+-----+-----+-----
PULSOMETER
AQUA-THRUSTER
[Illustration: FIG. 552.]
THE PULSOMETER.
_The original pulsometer_ was an instrument called by that name for
measuring the force and frequency of the pulse; it was invented in
1626 by Santovio of Padua, Italy. The term has been largely applied
to _a form of vacuum pump_, soon hereafter to be described; this
has a pulsative action—like a heart beat. The pulsometer, _the
aqua-thruster_, _the pulsator_, and other regular _double acting
two oval reservoirs_ (one filling while the other is discharging)
_automatic condensing steam vacuum pumps_ are all patterned after the
Thomas Savery pump shown in Fig. 552; this was patented in England in
1698. It is thus described:
“The upper end of the suction pipe shown at the mouth of the pit
consists of two branches, which are connected to similar branches on
the lower part of the forcing pipe N. The suction valves are at B A and
the forcing ones at E F, all opening upwards. Between these valves two
short curved tubes connect the bottoms of the receiver I M with the
branches, as represented, and two other bent tubes, P Q, unite the top
of the receivers with the boiler H. On top of this boiler, and forming
a part of it, is a stout round plate, having two openings of the same
size as the bore of the tubes last mentioned. In these openings the two
steam tubes P Q terminate. Between the openings, and on the under side
of the plate, is a movable disk, which by a short arm is connected to
an axle and moved by the long lever shown on the top of the boiler;
so that by moving this lever the disk can be made to open or close
either opening, so as to admit or exclude steam from the receivers, and
answering every purpose of a three-way cock.
[Illustration: FIG. 553.]
“The face of the disk is ground smooth, so as to fit close to the
under side of the plate, against which it is pressed by the steam.
The perpendicular axle by which the disk is turned passes through the
plate, and the opening is made tight by a stuffing-box. (The plate and
movable disk are represented in the small figure at the top, one of the
openings, Q, being covered by the disk and the other, P, exposed.)
A small cistern, U, is placed over the receivers, and kept supplied
with cold water from the forcing pipe by means of a ball cock, viz.:
a cock that is opened and shut by a ball floating in the cistern.
From the bottom of this cistern a short pipe, T, proceeds; and to
it is connected, by a swivel joint or stuffing-box, another one at
right angles. This pipe furnishes water to condense the steam in the
receivers, over both of which it can be moved by the rod attached to
the plug of the cock as shown in the figure. The upper cistern denotes
the place where the water raised by the engine is to be discharged.
“A communication is made between the boilers by a syphon or bent tube,
R, whose legs extend nearly to the bottom of the boilers. In the leg
within the small boiler is a valve opening upwards, which permits the
water of G to pass into H, but prevents any returning from the latter.
When the attendant wishes to inject into H a fresh supply of water, he
increases the little fire kept up under the boiler G (which is always
kept supplied with water by the pipe S), and as soon as the liquid
boils and the force of the steam exceeds that in H, the contents of G,
both steam and hot water, are forced through the valve; and thus H is
kept supplied without the action of the machine being stopped.
“The cock on the pipe S is then opened, the small boiler again charged,
and the water becomes gradually heated; so that by the time it is
wanted in the other boiler, a small addition to the fuel quickly raises
its temperature, and it is again forced in as before. The quantity
of water in the boilers was ascertained by _gauge cocks_. These were
inserted at the top (see figure) and pipes soldered to them descended
to different depths.”
[Illustration: FIG. 554.]
_The modern pulsometer_ is a low-service pump, and is not recommended
for duties exceeding about eighty feet total vertical service. With
this limitation, its uses are many and various and for some purposes it
is particularly adapted. Years of practical work with the pulsometer,
under widely different conditions, have demonstrated the merits claimed
for it.
[Illustration: FIG. 555.]
Its advantages are: 1. Its low cost, as it does not require an engine
or other machinery to operate it. _A steam pipe connecting it with the
boiler_ that is to furnish steam supply is all that is necessary, and
after the pump is once adjusted, it will always be in order with free
power when the steam is turned on. 2. It is absolutely noiseless in its
operation; the slight click of the steam ball-valve in the neck-piece,
as it changes its position, _is the only evidence that it is working_.
3. _In its capability of operation while in suspension_, and of being
lowered or raised and swung about without at all interfering with its
working.
The pulsometer does not _require oil_, having no pistons, glands,
stuffing-boxes, eccentrics, beams, levers, supplementary valves,
complicated mechanism, etc., which need attention and adjustment.
The Pulsometer Steam Pump Co., New York, makers of the pump and owners
of the word-symbol, “Pulsometer,” emphasize the importance of its
proper installation, and ask that the questions given in the note below
be answered when suggestions relative to the placing of the pump are
desired.
_The body of the pulsometer_ is shown in Fig. 555, and a _sectional
view_ in Fig. 556. It is a single casting consisting of two
bottle-shaped chambers, _A, A_, placed side by side. These are called
_working chambers_. They taper toward each other at their upper halves
and meet at their upper ends at a point at which is situated the _steam
valve-ball, C_. This oscillates with a slight rolling motion between
_the seats_, with which it makes a steam tight joint, formed at the
upper entrance to each of the working chambers, _A, A_.
NOTE.—For what purpose is the pump to be used? How many gallons per
minute or hour are to be pumped? Is the liquid hot, cold, clear or
gritty—fresh, salt, alkaline or acidulous? What will be the required
vertical height of delivery? What will be the horizontal length of
delivery? What will be the required vertical height of suction? What
will be the horizontal length of suction? Does the level of the
liquid vary? If so, how much? How many bends or elbows will there be
in delivery? How many bends or elbows will there be in suction? What
horse-power is the boiler? What is the average steam pressure at the
boiler?
A rough sketch showing how and where it is desired to place the pump
will be of considerable assistance in furnishing information.
The portion, _B_, of the pump, containing the steam ball-valve, _C_, is
called _the neck-piece_, and is a separate casting bolted to the main
body of the pump, so that it can be readily removed for renewal when
necessary. To the top of this neck-piece, _B, the neck-cap_ is bolted,
into which the steam supply pipe is screwed.
[Illustration: FIG. 556.]
The openings communicating between the chambers, _A, A_, and the
induction, or _foot-valve chamber, D_, are covered by suitable valves,
_E, E_, called _suction valves_, the valve seats, _F, F_, and _valve
guards, I, I_, which latter prevent the valves from opening too far.
A third chamber, _J_, called _the vacuum chamber_, is situated behind
the chambers, _A, A_, at their lower halves, and between them at their
upper, or tapering halves, and communicates with them through the round
opening in the induction, or foot-valve chamber, _D_.
A fourth chamber, called _the discharge chamber_, situated on the
lower side of the working chambers, _A, A_, opposite to the vacuum
chamber, _J_, and represented by the dotted lines in the sectional view
communicates with each of the working chambers, _A, A_, by passages at
the lower half of its intersection with these chambers. This discharge
chamber contains _the discharge valves, E, E_, their valve seats, _G,
G_, and the valve guards, _I, I_, which cover the passages leading from
chambers, _A, A_.
_The delivery pipe, H_, connects with the discharge opening in the top
of the discharge chamber by means of a flanged joint.
The induction, or foot-valve chamber, _D_, contains the valve, _E_,
its valve seat, _F_, and the guard, _I_, which serve the purpose of
holding the charge of water in the pump. The lower end of this chamber
is connected to the suction pipe by a flanged joint.
Parts, _K, K_, are _oval plates_ covering the openings through which
the seat, valve and guard are inserted, to their respective chambers,
and are fastened in position by means of clamps and bolts, _N, N_. The
ends of these clamps fit loosely into suitable recesses and are thus
held in position while the cover plates are being applied. Another
set of similar clamps and bolts serve in a like manner, to fasten the
seats, valves and guards in place.
The object in employing four openings to the pump, instead of two,
is to make it possible and convenient to get at the interior for
examination, and easy to remove all deposit that may form on the walls
of the chambers which could not be reached otherwise.
Vent plugs are inserted in the cover plates for the purpose of draining
off the water in the pump to prevent freezing.
Near the top of each of the working chambers, _A, A_, and of the
vacuum chamber, _J_, is a small tapped hole, into which is screwed
a brass air check-valve, so that its check hangs downward. The air
check-valves in the chambers, _A, A_, allow _a small quantity of air
to be automatically admitted above the water_, and ahead of the steam,
separating the steam and the water upon their first entrance, thus
preventing condensation, and forming an _air piston_, which is always
new and tight. The _air check-valve_ in the chamber, _J_, likewise
admits air automatically, which serves to cushion the ram action of
water consequent upon the alternate filling of the chambers, _A, A_.
[Illustration: FIG. 557.]
[Illustration: FIG. 558.]
[Illustration: FIG. 559.]
[Illustration: FIG. 560.]
_The action of the pulsometer is as follows_: When all chambers and
pipes are empty, the air check-valves have to be closed, and the
globe valve opened for an instant; then steam will enter one of the
chambers, expel the air, and condense, forming a vacuum. This operation
being repeated several times, both chambers will be filled with water
through the induction pipe. Each air-valve in the chambers must now
be opened a little, to secure a regular and successive action, which
will be recognized by the regular pulsations and smooth working of the
steam-ball without rattling.
Steam, being now admitted, continuously enters the chamber not closed
by the ball, and forces out the water through the discharge-valves,
until its surface is lowered below the discharge-orifice. At that
instant the steam begins to escape into the discharge-pipe, and
condenses; thus a partial vacuum is formed in the chamber. The water in
the other chamber now presses the ball, which rolls over and closes the
first chamber, when water enters through the induction-valves to fill
the vacuum. This operation alternately changes from one chamber to the
other.
_The principal parts of a pulsometer_ are shown in the seven figures
upon this and the preceding pages.
[Illustration: FIG. 561.]
[Illustration: FIG. 562.]
[Illustration: FIG. 563.]
Fig. 557 represents the regular flat valve, seat and guard, Fig. 558
the guard detached, while Fig. 559 is the plain flat rubber valve. The
valve seat for clean water is shown in Fig. 560.
[Illustration: FIG. 564.]
NOTE.—For emptying vats or tanks and for distributing the liquors
from one tank to another or throughout the building, the pulsometer
arranged as per accompanying ills., Fig. 564, will be found to be
of great usefulness. At convenient intervals along the steam main
and discharge main, suitable couplings can be provided for quickly
attaching a short section of steam and discharge hose, as the pump,
suspended from a trolley, is moved along from tank to tank.
In pumping muddy water or other liquids containing matter which would
obstruct the valve seat shown in Fig. 560 the ball valve, Fig. 561, is
used. The engraving illustrates this valve with its guard and seat.
Fig. 562 represents the neck-piece containing the ball steam valve,
while Fig. 563 conveys the idea of the manner of covering the ball by
the cap after which the neck-piece is ready to be bolted to the top of
pump.
_The Maslin automatic steam vacuum pump_ is presented in Fig. 554, page
271. Its principle is identical with that of the pulsometer but it
differs somewhat in detail, as for example, the three valves with their
seats, H, H, H, are introduced through one opening or hand-hole. The
two suction valves, E, E, are secured by one bolt, I, likewise the two
discharge valves, K. The combination of the foot valve, G, in the pump
requires no bolting on being held by the bolt, I.
The plain cover is of such a shape that no nuts are removed to afford
access to the valves; all that is necessary is to slack up one nut and
swing the cover to one side.
The valves are of very thick rubber but are cut away near the center
so that they readily yield to the pressure underneath, giving a full
area of opening. The two air valves are attached at the end of the
neck-piece.
There are no projecting set screws or bolts running through the main
body of this pump attended as they often are with more or less leakage.
A hook is provided to suspend the pump in a shaft or over sewer work.
The two drip cocks at the bottom drain the chambers when necessary to
prevent freezing, etc.
NOTE.—“One of the most important points to be attended to, and which
is so often overlooked, is that _dry_ steam should be supplied to the
pulsometer. Take steam from the highest part of the boiler. Do not
connect steam pipe to a pipe furnishing steam for any other purpose;
but if you have to take steam from a large steam pipe, tap it on the
upper side so as to avoid the drip caused by condensation in the
large pipe. When the boiler is some distance from the pulsometer the
steam pipe to it should be larger than is needed at the pulsometer,
and be protected by some non-conducting substance. Reduce to size
required at the pulsometer and provide a pet cock to draw off
condensed steam before starting it. Be sure and blow out steam pipe
thoroughly before connecting the pulsometer so as to remove any dirt,
rust or scale that may have accumulated in pipes, also remove all
burrs on ends of the pipe caused by cutting, and which in most cases
greatly decreases their capacity and effectiveness.”
The illustration, Fig. 565, represents the pulsometer and boiler
in portable form. This will be found a very convenient outfit for
certain classes of irrigation, and for pumping out flooded cellars,
excavations, etc. Also for sewer-trench excavating operations, where
water accumulates at different sections of the work, and where it is
desired to move the pump and boiler frequently.
[Illustration: FIG. 565.]
The pump is suspended from a strong framework and is controlled by a
chain hoist, by means of which it can readily be lowered or raised.
When the trench or ditch is too deep for the pulsometer to lift the
water to the surface of the ground by suction, the truck can be run
out on planks over the ditch, when the pump can be lowered to the
necessary suction distance from the water. Suitable lengths of steam
hose, with universal couplings, suction hose, also suitable lengths
of light flanged galvanized pipe for the discharge, which can be
readily connected may be carried on the truck, proper brackets being
provided for their reception. As the suction and discharge connections
are flanged, they can be connected or disconnected in a few minutes;
provision is made to prevent the pump from swinging.
PUMP SPEED
GOVERNORS
PUMP SPEED GOVERNORS.
The speed at which a pump is operated is a matter of more or less
importance, according to its widely varying conditions. In all
calculations regarding the capacity of a pump the regularity with which
it makes its “stroke” is taken into consideration; the uniformity of
the supply of water to a boiler is always a subject of anxiety to the
attendant. The capacity of a pump is usually determined by its number
of strokes in a given time, hence the need of a pump regulator or
governor.
[Illustration: FIG. 566.]
The governor is not only intended to maintain a uniform water pressure
in the mains, but to prevent the pump from racing whenever a greater
quantity of water is demanded than the pump is capable of delivering,
as in the case of bursted mains or hose, or any other contingency
whereby the pressure upon the discharge pipe is suddenly relieved.
Examples of pump governors or regulators follow.—
_The Mason Pump Governor._ This pump governor, shown in Figs. 566 and
567, is attached directly to the rock arm of the pump, and operates a
balance valve placed in the steam pipe, thereby exactly weighing the
pressure of steam to the needs of the pump. As all the working parts
are immersed in oil, the wear is reduced to a minimum.
[Illustration: FIG. 567.]
The Mason governor consists mainly of a cylindrical shell, or
reservoir, as shown in sectional view, filled with oil or glycerine.
The plunger, _A_, is connected with the arm, _I_, to some reciprocating
part of the pump and works simultaneously with the strokes of the pump,
thereby drawing the oil up through the check valve, _DD_, into the
chambers, _JJ_, whence it is forced alternately through the passages,
_BB_, through another set of check valves into the pressure chamber,
_EE_. The oil then runs through the orifice, _C_, the size of which is
controlled by a key inserted at, _N_, into the lower chamber, to be
re-pumped as before. In case the pump or engine works more rapidly than
is intended the oil is pumped into the chamber, _EE_, faster than it
can escape through the outlet at, _C_, and the piston, _GG_, is forced
upward, raising the lever, _L_, with its weight, and throttling the
steam. In case the pump runs more slowly than was intended, a reverse
action takes place, the weight on the end of the lever, _L_, forces
the piston, _GG_, down and more steam is admitted. As the orifice at,
_C_, can be increased or diminished by adjusting the screw at, _N_, the
governor can be set within reasonable limits to maintain any desired
speed. The piston, _GG_, fits over the stationary piston, forming an
oil dashpot, thereby preventing dancing of the governor. This dashpot
is fed from the pressure chamber, _E_, through a passage which is
controlled by an adjusting screw, _K_, which is set with a screwdriver,
after removing the cap screw, _T_. It requires no further attention
after being once adjusted.
For duplex pumps up to 2-inch steam pipe, inclusive, this governor is
fitted with a duplex valve, which prevents the escape of oil from the
pressure chamber through the orifice, _C_, and thereby prevents the
steam valve from opening wide during the momentary pause of the pump
piston.
This governor should be placed on the pump at some point where the
requisite motion can be obtained for operating it, and also in such
a way that a rod can be run from the knuckle joint on the top lever,
_I_, to the valve in the steam pipe, as shown in the engraving. Place
the valve in the pipe, so that the stem shall be in a direct line with
the knuckle joint on the lever, and pull out the valve stem to its
full extent. With the ball on the governor in its lowest position,
connect the valve rod to the lever. The governor is then ready to be
filled with oil. Remove the plug on top of the gauge glass, and fill
the governor about half full with a good, clean, light grade of mineral
oil. The governor is then ready to work.
Start the pump at about its maximum speed; place the key in the keyhole
on the side of the governor and turn to the right until the speed of
the pump has diminished slightly. Open the throttle valve wide, and the
pump will be under full control of the governor. Should there be much
dancing or fluctuation of the ball, remove the screw, _T_, insert a
small screwdriver, and screw the adjusting screw in, at _K_, until the
irregular motion ceases. After the governor has run a little while, it
will be found that the oil in the glass gauge has dropped considerably.
It should then be refilled, so that the glass will be about half full
when the governor is at work. Under no circumstances should the gauge
be full, as too much oil will prevent the ball from coming down and
opening the valve when the steam pressure falls. As there is no glass
pressure upon the glass gauge the governor may be filled while in
motion by removing the plug on the top of the gauge.
[Illustration: FIG. 568.]
_The Mason elevator pump pressure regulator._ This regulator,
illustrated in Fig. 569, is designed for use in connection with
the larger sizes of steam pumps operating hydraulic elevators. Its
important feature is in operating on the slightest change of pressure
opening to its fullest extent and closing the steam valve promptly and
positively.
Referring to sectional view, Fig. 570, the operation of this valve is
as follows: steam from the boiler enters the regulator at the inlet,
indicated by the arrows and passes through into the pump, which
continues in motion until the required water pressure is obtained
in the system, and through a 1/4-inch pipe connected to, _A_, acts
upon the diaphragm, _B_. This diaphragm is raised by the excess
water pressure, and carries with it the weighted lever, _F_, opens
the auxiliary valve, _D_, and admits the water pressure from the
connection, _E_, to the top of the piston, at the same time opens the
exhaust ports under the piston, and allows the water under the piston
to escape into the drip pipe, thereby pushing the piston down, closes
the steam valve and stops the pump.
[Illustration: FIG. 569.]
As soon as the pressure in the system is slightly reduced, the lever,
_F_, on account of this reduced pressure under the diaphragm, is forced
down by the weight, carries with it the auxiliary valve, _D_, opens the
exhaust to the top of the piston, and also admits water pressure under
the piston, which is forced up and opens the steam valve, and starts
the pump.
The speed controlling device of the style A governor shown in Fig.
571 is simple and can be so set as to prevent the pump from racing,
regardless of the drop in water pressure. Surrounding the upper end
of the valve stem is a coiled spring, which acts as a cushion for the
valve and stem, and by the use of a spring, the stem can be quite
small thus reducing the friction in the stuffing-box to a minimum. The
tension of this spring is sufficient to firmly seat the valve, but if
excessive pressure is exerted on the piston, which is often the case
when two or more pumps are connected to the same mains, the spring will
be compressed and will allow the sleeve to slide down on the stem, thus
relieving the valve of the increased strain, which would be liable to
injure it or buckle the stem.
[Illustration: FIG. 570.]
The regulating hand wheel remains cool, and can be manipulated without
injury to the hands. The regulation is very simple, and is quickly
adjusted by simply turning the wheel to the right or left, to increase
or decrease the pressure. No locking device is necessary, as the wheel
will remain in any set position.
The cylinder will not become coated with lime, but will retain its
smooth surface over which the piston travels, insuring free action,
with no leakage around the piston. The drip is located at the extreme
upper travel of the piston, so as to retain sufficient water in the
cylinder to prevent any air from coming in contact with leather piston
packing. This arrangement insures a tight piston as the leather packing
will remain soft and pliable and at the same time the water serves as a
lubricant for the interior of the cylinder.
[Illustration: FIG. 571.]
The hand wheel can be placed in different positions and all that is
necessary to make the change is to take out the bolts and move the
regulating hand wheel to the desired position. By this arrangement the
engineer can set the hand wheel regardless of the arrangement of the
steam piping.
All sizes, including 1-1/2-inch and smaller, are made as shown in style
B, Fig. 572, and are not provided with an automatic speed controlling
device. This style is made especially for boiler feed pumps and for
supply pumps for the street system of hot water heating. They are also
fitted with a special valve for pumps working under very high steam and
low water pressure.
[Illustration: FIG. 572.]
The finished parts of these Carr steam pump governors, Figs. 571 and
572, are nickel plated.
The valves and seats in these governors and regulators are renewable,
Fig. 573. The tools necessary to remove the seats are a wrench and a
flat piece of iron wide enough to span the lugs on top of the upper
seat. The upper seat is threaded and screwed into the upper opening
in the valve chamber. The lower valve seat is fitted into the lower
opening, a steam-tight fit, but is free to move sufficiently to
compensate for the expansion of the valve.
[Illustration: FIG. 573.]
The bridges, which unite the valve seats, contain about an equal
quantity of metal, and are of equal length with the post that binds
the valve discs, thus compensating for the expansion and contraction
of the metal and insuring a perfectly tight valve, regardless of the
temperature of the steam.
_The Holyoke Improved Speed Governor for water wheels_ is shown in
Figs. 574 and 575. The following is a description of the two figures
where the same letters are used to designate the parts appearing in
both illustrations:
The pulley, A, is the receiving pulley, and is designed to run at 400
revolutions per minute, receiving its power from the water-wheel shaft,
or countershaft belted from the same.
Contained in the pulley, A, are the two governing weights, BB, of which
the centrifugal forces are overcome by the springs, CC. The varying
motions of the governing weights, BB, are transmitted through racks
and pinions in the hub of pulley, A, to levers, K and L, which operate
the valve, N, admitting water under a light pressure to the cylinder,
O. The water is admitted to the cylinder, O, through ports at either
end, causing the piston to move forward or backward, governed by the
movement of the governing weights, BB.
[Illustration: FIG. 574.]
[Illustration: FIG. 575.]
The pulley, A, is keyed to the main shaft, and at the opposite end is
keyed a bevel pinion running in mesh with a bevel gear on either side,
all of which are contained in the gear-case, P. These gears cause
the clutch discs, D, to run in opposite directions. In each disc is
a clutch, E, keyed to a shaft, transmitting power to the pinion, S,
running in mesh with the spur gear, R, which is loose on the shaft, J,
and transmits its power through the pin clutch, T, to gate shaft, J.
The gate shaft, J, is connected by a pair of bevel gears to the shaft
and hand wheel, Q.
The motion of the piston rod, I, caused by the movement of piston in
cylinder, O, is carried by the lever, G, to the clutch shaft, F, by
means of the pivoted nut at V. The clutch shaft, F, operates either
clutch, E, corresponding to the movement of the governing weights, BB,
caused by the variation in speed. From the clutch thus engaged, the
power is carried by the clutch shaft, F, through the gears, S and R,
and the pin clutch, T, to the gate shaft, J.
[Illustration: FIG. 576.]
The makers of the machine here described, say: “In the year 1902
our attention was called to a new governor invented by _Nathaniel
Lombard_, and after finding by actual tests that this governor
possessed advantages over all others then in use, we were induced to
make arrangements for its manufacture and sale. Two years have been
spent in improving and perfecting this machine, hence the name ‘The
Improved Governor.’”
The governor is provided with a steadying device operated by the chain,
H. The gate shaft, J, is designed to make four, six or eight turns to
open the gate, four being the regular number.
The receiving pulley and governor gate shaft may revolve in either
direction, as desired.
The receiving pulley is designed to run at 400 revolutions per minute,
and is driven by a 4-inch double belt.
The governor gate shaft may be arranged to open the gates in four, six
or eight turns, and may be extended on either or both sides of the
governor to meet the necessary requirements.
The governor is capable of exerting a pressure ranging from 25,000 to
50,000 foot pounds on the governor gate shaft.
The advantages claimed for this improvement on _the Lombard governor_
are thus stated:
1. It requires only a light water pressure to handle the heaviest gates.
2. It is simple in construction. All parts are easy of access.
3. There are no pumps working under high pressure.
4. There are no dash pots to get out of adjustment, due to the change
in temperature of oil, etc.
5. There is but one belt on this machine.
6. All parts which are constantly in motion are equipped with
ring-oiling bearings.
Fig. 576 is an illustration of the mechanism necessary to raise and
lower _the head gates_ which are used to admit and regulate, also to
shut off the water supply from pond or lake _to the flume conveying it
to the wheel_. In this case there are two head gates having racks upon
the upright timbers connecting with the gates. Two shrouded pinions
engage these racks, which are keyed upon a shaft having a large spur
wheel at its end, as represented. A pinion upon a second shaft engages
this spur wheel which in turn has also a spur wheel which engages a
pinion upon the crank shaft having two cranks opposite one another. By
means of these cranks with two to four men upon each crank the gates
are operated very satisfactorily. These shafts and gears are mounted
upon heavy cast iron brackets bolted to the floor. Altogether it forms
a very massive piece of mechanism.
_The Utility combination pump governor_ is shown in the figure below.
This mechanism may be bolted on any tank or receiver where the water
level is to be automatically maintained. It consists of a closed pocket
containing a float, A, which rises and falls with the water level
inside the tank.
When the water rises above the desired level the float opens the
throttle valve and starts the pump, and when it subsides the float
falls and shuts off the steam.
[Illustration: Utility combination pump governor.]
CONDENSING
APPARATUS
[Illustration: FIG. 577.]
CONDENSING APPARATUS.
_A condenser_ is an apparatus, separate from the cylinder, in which
exhaust steam is condensed by the action of cold water; _condensation_
is the act or process of reducing, _by depression of temperature or
increase of pressure_, etc., to another and denser form, as gas to the
condition of a liquid or steam to water. There is an electrical device
called “a condenser” which must not be confounded with the hydraulic
apparatus of the same name; there is also an optical instrument
designated by the same term, which belongs to still another division of
practical science.
_A vacuum_ is defined very properly as an empty space; a space in
which there is neither steam, water or air—the absolute absence of
everything. The condenser is the apparatus by which, through the
cooling of the steam by means of cold water, a vacuum is obtained.
_The steam after expelling the air from the condenser fills it with its
own volume_ which is at atmospheric pressure nearly 1700 times that of
the same weight of water.
Now when a vessel is filled with steam at atmospheric pressure, and
this steam is cooled by external application of cold water, it will
immediately give up its heat, which will pass off in the cooling water,
and _the steam will again appear in a liquid state_, occupying only
1/1700 part of its original volume.
But if the vessel be perfectly tight and none of the outside air can
enter, the space in the vessel not occupied by the water contains
nothing, as before stated. The air exerting a pressure of nearly
15 pounds to the square inch of the surface of the vessel tries to
collapse it; now if we take a cylinder fitted with a piston and connect
its closed end to this vessel by means of a pipe, the atmospheric
pressure will push this piston down. The old low pressure engines were
operated almost entirely upon this principle, the steam only served to
push the piston up and exhaust the air from the cylinder.
In Fig. 578 is exhibited the effect of jets of water from a spray
nozzle meeting a jet of steam; the latter instead of filling the space
with steam is returned to its original condition of water and the space
as shown becomes a vacuum.
Briefly stated condensation and the production of a vacuum may be used
to advantage in the following ways:
1. By increasing the power without increasing the fuel consumption.
2. By saving fuel without reducing the output of power.
3. By saving the boiler feed water required in proportion to the saving
of fuel.
4. By furnishing boiler feed water free from lime and other scaling
impurities.
5. By preventing the noise of the escaping exhaust steam.
6. By permitting the boiler pressure to be lowered ten to twenty pounds
without reducing the power or the economy of the engine.
The discovery of the advantages arising from the condensation of steam
by _direct contact with water_ was accidental.
[Illustration: FIG. 578.]
In the earliest construction of steam-engines the desired vacuum was
produced by the circulation of water through a jacket around the
cylinder. This was a slow and tedious process, the engine making only
seven or eight strokes per minute. “An accidental unusual circumstance
pointed out the remedy, and greatly increased the effect. As the
engine was at work, the attendants were one day surprised to see it
make several strokes much quicker than usual; and upon searching for
the cause, they found, says Desaguliers, ‘a hole through the piston
which let the cold water (kept upon the piston to prevent the entrance
of air at the packing) into the space underneath.’ The water falling
through the steam condensed it almost instantaneously, and produced
a vacuum with far less water than when applied to the exterior of
the cylinder. This led Newcomen to remove the outer cylinder, _and
to insert the lower end of the water pipe into the bottom of the
cylinder_, so that on opening a cock a jet of cold water was projected
through the vapor. This beautiful device is the origin of the injection
pipe with a spray nozzle still used in low-pressure engines.”
The apparatus described above is called the _jet-condenser_ and is
in use up to the present day in various forms. In the Fig. 577, page
298, the jet is shown at C. It will be understood that steam enters
through the cock D and comes in contact with a spray of cold water at
the bottom, where it is condensed and passes into the air pump through
which it is discharged.
By this diagram, Fig. 577, may be understood in a simple yet accurate
manner _the course of steam from the time it leaves the boiler until it
is discharged from the condenser_.
Referring to the upper section of the plate, a sectional view of a
steam cylinder, jet condenser, air pump and exhaust piping is shown.
The high pressure steam “aa” is represented by dark shading, and the
low pressure or expanded steam “bb” by lighter shading.
The steam enters the side “aa,” is cut off, and expansion takes place
moving the piston in the direction of the arrow to the end of the
stroke. The exhaust valve now opens and the piston starts to return.
The low pressure steam instead of passing direct to the atmosphere, as
is the case of a high pressure engine, flows into a chamber “C,” and is
brought in contact with a spray of cold water. The heat being absorbed
by the water, the steam is condensed and reduced in volume, thus
forming a vacuum. It is, however, necessary to remove the water formed
by the condensed steam together with the water admitted to condense the
steam, also a small amount of air and vapor. For this purpose, a pump
is required, which is called the air pump.
[Illustration: FIG. 579.]
[Illustration: FIG. 580.]
[Illustration: FIG. 581.]
Condensers are classified into _surface condensers and jet condensers_,
both again being divided into direct connected and indirect connected
condensers.
The surface condenser (see Fig. 579) is mainly used in marine practice
because it gives a better vacuum, and keeps the condensed steam
separate from the cooling water; it consists of a vessel, of varied
shapes, having a number of brass tubes passing from head to head. The
ends of this vessel are closed by double heads, the tubes are expanded
into the inner one on one end, while their other ends pass through
stuffing-boxes in the other inner head.
The “admiralty” or rectangular surface condenser is represented in Fig.
579. This form occupies less floor space than the round shell, and is
preferred upon steam yachts and small vessels.
Steam is condensed on its introduction at the top of the apparatus
where it comes in contact with the cool surfaces of the tubes. Through
these water is circulated by a centrifugal pump driven usually by a
separate engine.
[Illustration: FIG. 582.]
_The water of condensation_ leaves the condenser at the bottom and is
drawn off by the vacuum pump. _The water from the circulating pump_
enters at the bottom right-hand end; following the direction indicated
by the arrows, it flows through the lower half of the tubes towards
the left whence it returns through the upper half of the tubes towards
the right and escapes overboard through the water outlet pipe.
It will be observed that the coolest water encounters the lowest
temperature of steam at the bottom, hence the best results are reached.
There is also a baffle plate just above the upper row of tubes to
compel a uniform distribution of exhaust steam among the tubes, as
shown in the engraving.
These tubes are usually small—1/2″ outside diameter—of brass and coated
with tin inside and outside to prevent galvanic action which is liable
to attack the brass tubes and cause them to corrode.
Fig. 581 shows an end view of the right-hand head of the surface
condenser here described.
[Illustration: FIG. 583.]
A single tube is shown in detail in Fig. 580. One end of the tube is
drawn sufficiently thick to chase upon it deep screw threads, while a
slot facilitates its removal by a screw-driving tool. The other end is
packed and held in place by a screw gland, which is also provided with
a slot. In this way the tube is firmly held in one head, and, though
tightly fitted in the other, is free to move longitudinally under the
influence of expansion or contraction, due to the varying heat.
In some cases engineers prefer the ordinary arrangement of screw glands
at both ends of the tubes, with the usual wick packing.
The mechanism illustrated in Figs. 582 and 583 shows _a combined
condenser and feed-water heater_. A compact and efficient method of
heating the feed-water from the hot well is of great importance; this
is the case in cold weather when the circulating water is at a low
temperature.
_The Volz apparatus_ is a combined condenser and feed-water heater; the
shell or exhaust steam chamber contains a set of tubes, through which
the feed-water passes, while the lower part contains the condensing
tubes, both parts being in proper communication with their respective
water chambers. The heater tubes being located immediately adjacent
to the exhaust inlet, are exposed to the hottest steam, and the
feed-water becomes nearly as high temperature as that of the vacuum.
Pages 304 and 305 show the sectional and outside views. The enclosing
shell containing the combined heater and condenser is a well ribbed
cylindrical iron casting; free and independent access is provided to
either set of tubes by removing corresponding heads.
The illustration, Fig. 584, is a longitudinal section of one side of
the condenser pump, and also a section of the condenser cone, spray
pipe, exhaust elbow and injection elbow. “A” is the exhaust to which is
connected the pipe that conducts to the apparatus the steam or vapor
that is to be condensed. The injection water is conveyed by a pipe
attached to the injection opening at “B.” “C” is the spray pipe, and
has, at its lower extremity, a number of vertical slits through which
the injection water passes and spreads out into thin sheets.
The spray cone “D” scatters the water passing over it, and thus ensures
a rapid intermixture with the steam. This spray cone is adjustable
by means of a stem passing through a stuffing-box at the top of the
condenser, and is operated by the handle “E.” The cone should be left
far enough down to pass the quantity of water needed for condensation.
_All regulation of the injection water must be done by an injection
valve placed in the injection pipe at a convenient point._
NOTE.—The surface condensers, Figs. 579-581, are made by the Wheeler
Condenser and Engineering Co., New York, as are also the Volz
combined surface condenser and feed water heater, shown in Figs. 582
and 583.
_The operation of this condensing apparatus is as follows_: steam being
admitted to the cylinders “K,” so as to set the pump in motion, a
vacuum is formed in the condenser, the engine cylinder, the connecting
exhaust pipe, and the injection pipe. This causes the injection water
to enter through the injection pipe attached at “B” and spray pipe “C”
into the condenser cone “F.” The main engine being started, the exhaust
steam enters through the exhaust pipe at “A,” and, coming in contact
with the cold water, is rapidly condensed. The velocity of the steam is
communicated to the water, and the whole passes through the cone “F”
into the pump “G” at a high velocity, carrying with it, in a comingled
condition the air or uncondensable vapor which enters the condenser
with the steam. The mingled air and water is discharged by the pump
through the valves and pipe at “J” before sufficient time or space has
been allowed for separation to occur.
[Illustration: FIG. 584.]
_The exhaust steam induction condenser_ is based upon the same
principle heretofore explained under the section relating to injectors.
See Fig. 585.
[Illustration: FIG. 585.]
The exhaust steam enters through the nozzle, A. The injection water
surrounds this nozzle and issues downward through the annular space
between the nozzle and the main casting. The steam meeting the water
is condensed, and by virtue of its weight and of the momentum which
it has acquired in flowing into the vacuum the resulting water
continues downward, its velocity being further increased, and the
column solidified by the contraction of the nozzle shown. The air is
in this way carried along with the water and it is impossible for it
to get back against the rapidly flowing steam in the contracted neck.
The condenser will lift its own water twenty feet or so. When water
can be had under sufficient head to thus feed itself into the system,
and the hot-well can at the same time be so situated as to drain
itself, it makes a remarkably simple and efficient arrangement. In
case the elevation is so great that a pump has to be used to force the
injection, the pump has to do less work than the ordinary air pump, and
its exhaust can be used to heat the feed water.
_The Bulkley “Injector” condenser_ is shown in Fig. 586, arranged so
that the condensing water is supplied by a pump. The condenser is
connected to a vertical exhaust pipe from the engine, at a height
of about 34 feet above the level of the “hot-well.” An air-tight
discharge pipe extends from the condenser nearly to the bottom of the
“hot-well,” as shown in the engraving.
The condenser is supplied by a pump as shown, or from a tank, or from
a natural “head” of water; the action is continuous, the water being
delivered into the “hot-well” below. The area of the contracted “neck”
of the condenser is greater than that of the annular water inlet
described above, and the height of the water column overcomes the
pressure of the atmosphere without.
[Illustration: FIG. 586.]
The supply pump delivers cool water only, and is therefore but
one-third of the size of the air-pump. The pressure of the atmosphere
elevates the water about 26 feet to the condenser.
The accompanying diagrams, Figs. 587 and 588, are worthy of study.
They represent _a condenser plant_ designed by the Schutte & Koerting
Co., Philadelphia, and placed on steam-vessels plying on fresh water.
In these drawings the parts are designed by descriptive lettering
instead the ordinary way of reference figures; this adds to the
convenience of the student in considering this novel application of the
condenser-injector, the action of which is described in the following
paragraphs.
[Illustration: FIG. 587.]
For steamers plying on fresh water lakes, bays and rivers it is
unnecessary to go to the expense of installing surface condensers such
as are used in salt water; keel condensers, however, are used in both
cases.
[Illustration: FIG. 588.]
_The keel condenser_ consists of two copper or brass pipes running
parallel and close to the keel, one on each side united by a return
bend at the stern post. The forward ends are connected, one to the
exhaust pipe of the engine while the other end is attached to the
suction of the air pump.
In other cases both forward ends are attached to the exhaust pipe of
the steam engine while the water of condensation is drawn through a
smaller pipe connected with the return bend at the stern post which is
the lowest part of the keel condenser.
Fig. 587 is much used for vessels running in fresh water. The
illustration is a two-thirds midship section of a vessel with pipe
connections to the bilge—bottom injection—side injection into the
centrifugal pump, thence upward through suction pipe into the ejector
condenser where it meets and condenses the exhaust steam from the
engine and so on through the discharge pipe overboard. The plan of
piping with valves, drain pipes and heater are shown in Fig. 588.
In case of the failure of any of the details of this mechanism to
perform their respective functions a free exhaust valve and pipe is
provided which may be brought instantly into use. The discharge pipe
has a “kink” in it to form a water seal, as represented with a plug
underneath to drain in case of frost, or in laying up the vessel in
winter. A pipe leads from globe valve (under discharge elbow) to feed
pump for hot water.
_Condensing Surface Required._ In the early days of the surface
condenser it was thought necessary to provide a cooling surface in the
condenser equal to the heating surface in the boilers, the idea being
that it would take as much surface to transfer the heat from a pound
of steam to the cooling water and condense the steam as it would to
transfer the heat from the hot gases to the water in the boiler and
convert it into steam. The difference in temperature, too, between the
hot gases and the water in the boiler is considerably greater than that
between the steam in the condenser and the cooling water.
[Illustration: Surface Condenser.]
NOTE.—The following list gives the numbers with the corresponding
names of the parts of _the surface condenser_, shown in the above
outline sketch: 1, condenser shell; 2, outside heads; 3, exhaust
inlet; 4, exhaust outlet; 5, water inlet; 6, water outlet; 7,
peep holes; 8, tube heads; 9, partition; 10, rib; 11, tubes; 12,
stuffing-boxes.
[Illustration: Jet Condenser.]
NOTE.—The numbers and names of parts in the above figure,
representing in outline a _jet condenser_, are as follows: 1,
condenser body; 2, exhaust inlet; 3, discharge; 4, injection valve;
5, spray pipe; 6, spraying device.
_Steam, however, gives up its heat to a relatively cool surface much
more readily than do the hot furnace gases_, and the positively
circulated cooling water takes up that heat and keeps the temperature
of the surface down, while in a boiler the absorption depends in a
great measure upon the ability of the water by natural circulation
to get into contact with the surface and take up the heat by
evaporization. It has been found, therefore, that a much smaller
surface will suffice in a condenser than in the boilers which it serves.
The Wheeler Condenser and Engineering Company, who make a specialty
of surface condensers, say that one square foot of cooling surface is
usually allowed to each 10 pounds of steam to be condensed per hour,
with the condensing water at a normal temperature not exceeding 75°.
This figure seems to be generally used for average conditions. Special
cases require special treatment.
For service in the tropics the cooling surface should be at least ten
per cent. greater than this estimate. Where there is an abundance
of circulating water the surface may be much less, as with a keel
condenser, where 50 pounds of steam is sometimes condensed per hour per
square foot of surface; or a water works engine, where all the water
pumped is discharged through the condenser and not appreciably raised
in temperature, probably condensing 20 to 40 pounds of steam per hour
per square foot of surface.
Under the division of this volume devoted to “air and vacuum pumps,”
much information has been given relating to the principles of the
condensation of steam and also some illustrations of working machines.
Still it may be well to say this, in addition, that—
All questions in regard to a vacuum become plain when we consider
that the atmosphere itself exerts a pressure of nearly 15 pounds,
and measure everything from an absolute zero, 15 pounds below the
atmospheric pressure. We live at the bottom of an ocean of air. The
winds are its currents; we can heat it, cool it, breathe and handle it,
weigh it, and pump it as we would water. The depth of this atmospheric
ocean cannot be determined as positively as could one of liquid, for
the air is elastic and expands as the pressure decreases in the upper
layers. Its depth is variously estimated at from 20 to 212 miles. _We
can, however, determine very simply how much pressure it exerts per
square inch._
UTILITIES AND
ATTACHMENTS
[Illustration: WORKING SHIP PUMPS BY ROPES.]
UTILITIES AND ATTACHMENTS.
_Utility_ is a Latin word meaning the same as the Saxon word
_usefulness_, hence a utility is something to be used to advantage.
An _attachment_ is that by which one thing is connected to another;
some adjunct attached to a machine or instrument to enable it to do
a special work; these are too numerous to be described in this work;
moreover their number is being so constantly added to that it would be
vain to make the attempt. A few examples only follow.
_The Receiver_ is one of the most important and useful parts or
connections of a steam pump.
This apparatus, frequently called “Pump and Governor,” and illustrated
in Figs. 589, 590 and 591, is designed to automatically drain heating
systems and machines or appliances used in manufacturing which depend
upon a free circulation of steam for their efficiency. It furthermore
is arranged to automatically pump the water of condensation drained
from such systems back to the boilers without loss of heat.
By this operation it serves a double purpose: first to automatically
relieve the system of the water of condensation constantly collecting
therein, thus insuring a free and unobstructed circulation, and,
incidentally, preventing snapping and hammering in the piping, which
in many cases is due to entrained water; and second, to automatically
deliver this water, which in many cases is at the boiling point,
directly to the boilers without the intervention of tanks or other
devices commonly used. Not only does it relieve the system of a
troublesome factor, but it introduces a supply of feed water to the
boiler at a temperature impossible otherwise without the use of a
special water heater.
The economy resulting from its use is unquestionable, and the
satisfactory and increasing use of this machine leaves no doubt as to
its efficiency.
As will be seen by the illustrations, the apparatus consists of a
cylinder or oval closed receiver, which, together with the pump, is
mounted upon and secured to a substantial base, making the whole
machine compact and self-contained.
The automatic action of the pump and its speed are controlled by
a float in the receiver operating directly, without the use of
intervening levers, cranks and stuffing boxes, to open or close a
governor valve in the steam supply pipe to the pump, thus making the
action of the pump conditional upon the rise and fall of the float in
the receiver.
[Illustration: FIG. 589.]
In each of the three receivers shown there is _a ball float_ which
appears through the side of the receiver, Fig. 590; these depend upon
the principle of specific gravity for their operation. The lever
fastened to the ball float operates the throttle valve of the pump; as
the vessel fills with water the float rises opens the throttle valve,
and starts the pump.
In Fig. 589 is shown the Deane automatic duplex steam pump and
_receiver_ fitted with valves for hot water; it is also provided with
three separate inlets for convenience in connecting the returns.
In placing the apparatus, it is only necessary to so locate it that all
returns will drain naturally towards receiver and that there are no
pockets in the piping.
When it is desired to use the automatic receiver as the sole means of
feeding the boilers, it will be necessary to introduce a small supply
of water from some outside source to equalize the loss which occurs. It
is desirable that this water should flow into receiver rather than into
discharge pipe.
[Illustration: FIG. 590.]
[Illustration: FIG. 591.]
Fig. 590 shows a Mason steam pump with receiver attached. This pump
is described elsewhere at length. Fig. 591 represents the Worthington
duplex steam pump with its specially designed receiver.
The _ball cock_ is a faucet which is opened or closed by means of a
ball floating on the surface of the water as it rises and falls in the
vessel.
In the illustration, Fig. 592, to be seen below the principle of its
operation may be discerned. The fall of water in the tank lowers the
float and opens the valve (which has in this case a rubber seat) and
a rise of water in the tank closes the valve, hence this ball float
controls and maintains a constant water level in the tank.
[Illustration: FIG. 592.]
The float is a hollow ball of copper attached to one end of a lever
while the other end is pivoted by a pin through it and the side of the
shell of the valve. The valve itself is held by a screw to the lever
and resembles very much an inverted lever safety valve.
This principle of construction and operation is applied to many devices
among which is that described on page 318 relating to pump receivers.
The apparatus constitutes an automatic arrangement for keeping the
water at a certain height. It is useful in cisterns, water backs,
boilers, etc., where the supply is constant, the demand intermittent.
TANKS AND CISTERNS.
[Illustration: FIG. 593.]
_A tank is an artificial receptacle_ for liquids, thus: _a tank
engine_ is one which carries the water and fuel it requires, thereby
dispensing with a tender; _tank-iron_ or steel is common plate used
in building tanks. Steel is cheaper than sheet-iron. _A cistern is
primarily a natural reservoir_—a hollow place containing water; more
commonly an underground reservoir or tank. _Closed pressure tanks_ are
usually cylindrical shells similar to a horizontal steam boiler, having
bumped or rounded heads to save bracing. Closed pressure tanks are
used extensively in connection with hydraulic elevators; the requisite
pressure for these was formerly derived from an open tank installed
upon the roof of the building, but the closed pressure tank, located
in the engine room, now very generally takes the place of the open tank.
_A closed pressure tank_ is shown in Fig. 596 in use with a hydraulic
elevator.
_A reservoir_ is a place where water is collected and kept for use
when wanted, so as to supply a fountain, a canal or a city by means of
aqueducts or to drive a mill-wheel or the like.
[Illustration: FIG. 594.]
_A receiving reservoir_ is a principal reservoir into which an
aqueduct or rising main, delivers water and from which _a distributing
reservoir_ draws its supply.
_A graduated tank_ is one fitted with water gauges and indicating
marks, at different heights, between which, the capacity of the tank is
shown.
_A ship’s ballast tank_ is the compartment for water to be pumped in
and out for the purpose of insuring the proper stability of the vessel,
to avoid capsizing and to secure the greatest effectiveness of the
propelling power.
[Illustration: FIG. 595.]
_A vat_ is a cistern or tub, especially one used for holding liquors
in an immature state, as chemical preparations and tanning liquor for
leather. Fig. 594.
_A tub_ is an open wooden vessel formed with staves, bottom and hoops;
a kind of short cask, half barrel or firkin, usually with but one head.
Fig. 595.
_A gallon_ (U.S.) is equal to 231 cubic inches or 0.13368 cubic feet
and weighs 8-1/3 lbs. nearly, (i.e. 8.3356). This is almost exactly
equivalent to a cylinder 7 inches in diameter and 6 inches in height.
_The imperial gallon of England_ contains 277.274 cubic inches, and is
equivalent to 1.2 U.S. gallons and at 62° Fah. weighs 10 lbs.
_A cubic foot_ contains 7-4805/10000 (7-1/2 nearly) U.S. gallons, and
weighs 62-355/1000 (62-1/3 nearly) lbs.
_A barrel_ = 31-1/2 gallons. 1 hogshead = 2 bbls. = 63 gallons.
_The strength of a tank_ is of the first importance; 235-1/2 gallons of
water weigh as much as a ton of coal, but unlike the latter, it presses
in all directions. Immense losses both of life and property have been
caused by the “bursting” or giving way of tanks; particularly of those
of a considerable size and elevation.
[Illustration: FIG. 596.]
NOTE.—_Tank Valves._ The “Corcoran” valve is made for either side or
bottom outlet and for 1, 1-1/4, 1-1/2, 2 and 2-1/2 inch pipe; its
action is automatic; the pull by which it is operated is controlled
by a ratchet. This valve closes the pipe inside the tank. It thus
becomes easy to empty the pipes in order to prevent freezing. _The
hoops, lugs and lock nut nipples_ are important parts of a well
constructed tank. _The foundations_ upon which tanks are supported
should be carefully considered, as the average weight of a well made
tank, when full of water, is about five tons to 1000 gallons.
The following table gives the capacity of round tanks or cisterns for
each 12 inches in depth, if the tank is 24 inches deep instead of 12
inches, the result would be, twice the number of gallons.
TABLE.
DIAM. GALL.
25 feet 3671
20 „ 2349
15 „ 1321
14 „ 1150
13 „ 992
12 „ 846
11 „ 710
10 „ 587
9 „ 475
8 „ 376
7 „ 287
6-1/2 „ 247
6 „ 211
5 „ 147
4 „ 94
3 „ 53
2-1/2 „ 36
2 „ 23
The contents of cisterns and tanks are estimated either in gallons or
in cubic feet. _The weight of water in any cistern or tank_ can be
ascertained by multiplying the number of gallons by the weight of one
gallon, which is 8-1/3 pounds, 8.333. For instance, taking the largest
cistern in the above table containing 3671 gallons: 3671 × 8.33 =
30579.43 lbs. (nearly).
_If the cistern is rectangular_, the number of gallons and weight of
water are found by multiplying the dimensions of the cistern to get the
cubical contents. For instance, for a cistern or tank 96 inches long,
72 inches wide, and 48 inches deep, the formula would be: 96 × 72 × 48
= 331,776 cubic inches.
As a gallon contains 231 cubic inches; 331,776 divided by 231 gives
1,436 gallons, which multiplied by 8.33 will give the weight of water
in the cistern. Fig. 594.
_For round cisterns or tanks_, the rule is: Area of bottom on inside
multiplied by the height, equals cubical capacity. For instance, taking
the last tank or cistern in the table: area of 24 inches (diameter)
is 452.39, which multiplied by 12 inches (height) gives 5527.6 cubic
inches, and this divided by 231 cubic inches in a gallon gives 23
gallons. Fig. 595.
_Rule for obtaining the contents of a barrel in gallons._ Take the
diameter at the bung, then square it, double it, then add square of
head diameter; multiply this sum by length of cask, and that product
by .2618 which will give volume in cubic inches; this, divided by 231,
will give result in gallons.
STRAINERS FOR SUCTION PIPES,
It is very desirable to place an efficient strainer on the suction pipe
of a pump where there is the least suspicion that the water contains
any sediment or floating matter.
Several of these useful pump attachments have been already shown,
connected with pumps, in previous sections of this work, but a few more
are here added.
Fig. 597 exhibits a cross section of a strainer of large capacity of
long and satisfactory use. It has a semi-cylindrical vessel located
in one side of the side pipe. Holes are drilled through the flat side
extending across the diameter of the side pipe; any floating matter
which will not pass through the holes collects in this strainer vessel
and may be easily removed.
[Illustration: FIGS. 597 AND 598.]
Fig. 598 represents a longitudinal section of this strainer. The top of
the chamber is covered by a bonnet secured by a claw having one bolt,
so that by unscrewing this bolt the claw and bonnet may be unfastened
and the settling chamber with perforated plate withdrawn.
A suction valve with double strainer is represented by Fig. 599, in
which the outer screen is raised for cleaning. In lowering, it is
guided to its place by the cage around the foot valve chest, as will be
seen in Fig. 600, which is a sectional view of this same valve. The
suction pipe extension enables the pump to draw water when its surface
has fallen below the top of strainer and also below the foot valves.
This is often a great advantage where water is scarce and every gallon
is needed.
_This foot valve is a “double clack”_ hinged in the center. There
are no openings or perforations in the bottom plate. Fig. 601 is a
very convenient form of strainer for large pipes and where it is an
advantage to have the strainer in the engine-room or near the pump.
This strainer, like Fig. 597, can be lifted out for cleaning by
removing the claw and bonnet. The chamber may be washed out by removing
the plug at the bottom.
[Illustration: FIG. 599.]
[Illustration: FIG. 600.]
A most convenient vacuum chamber and strainer is represented in Fig.
602; it is located near the pump. By removing the suction chamber the
basket or strainer may be lifted out by the handle under the arrow.
The outlet is generally attached directly to the pump. The pump may be
charged by removing the “priming plug” and inserting a hose, with water
turned on.
_Steam boiler feed water impurities_ consist mainly of chemical
substances which are unaffected—as may be readily supposed—by
mechanical devices just described; these impurities are largely
invisible being dissolved in the water and hence, also, considering
their variety, are most difficult to contend with. How to avoid the
actual evils arising from the presence of foreign matter in feed water
is of the first importance in steam economy; enormous losses of money,
danger to life and property are involved in it. It has been said that
there are more millions of treasure to be made by properly “treating”
the water which enters the steam generators of the world than can be
extracted from its gold mines.
[Illustration: FIG. 601.]
[Illustration: FIG. 602.]
NOTE.—Strangely, investigation has proved that water of this purity
rapidly corrodes iron, and attacks even pure iron and steel more
readily than “hard” water does, and sometimes gives a great deal of
trouble where the metal is not homogeneous. Marine boilers would be
rapidly ruined by pure distilled water if not previously “scaled”
about 1/32 of an inch.
To deal properly with this subject the science of chemistry must
be largely drawn upon; chemically pure water is that which has no
impurities, and may be described as colorless, tasteless, without
smell, transparent, and in a very slight degree compressible, and, were
a quantity evaporated from a perfectly clean vessel, there would be
no solid matter remaining. Now, in dealing with the impurities inside
a boiler, it is to be observed _that in no sense do they change the
essential nature of water itself_. The impurities are simply foreign
bodies, which have no legitimate place in the boiler, and are to be
expelled as thoroughly as possible.
The chemical substances to be eliminated are indicated in the note
below. Water, on becoming steam, separates from the impurities which it
may have contained, and these form sediment and incrustation. This is
an important fact.
_Corrosion_ is simply rusting or wasting away of the surfaces of the
metals. Incrustation means simply a coating over.
Several approved recipes and “notes” of instruction for removing
sediment and incrustation from steam boilers will be found near the
close of this volume.
NOTE.—Analysis of average boiler scale. Parts per 100 parts of
deposit.
Silica .042 parts
Oxides of iron and aluminium .044 „
Carbonate of lime 30.780 „
Carbonate of magnesia 51.733 „
Sulphate of soda Trace
Chloride of sodium Trace
Carbonate of soda 9.341 „
Organic matter 8.060 „
------------
Total solids 100. parts
The percentage only of each ingredient the scale is composed of is
given, as it cannot be told how much water was evaporated to leave
this amount of solid matter.
THE WATER METER.
Water meters, or measurers, are constructed upon two general
principles: 1, an arrangement called an “_inferential meter_” made
to divert a certain proportion of the water passing in the main pipe
and by measuring accurately the small stream diverted, _to infer_, or
estimate the larger quantity; 2, _the positive meter_; rotary piston
meters are of the latter class.
[Illustration: FIG. 603.]
[Illustration:
LONGITUDINAL SECTION.
TRANSVERSE SECTION.
FIGS. 604, 605.]
The distinctive difference between the two is, that the positive
meter measures water by means of a chamber alternately filled and
emptied. In most of these the flow of water ceases when, by any
derangement, the motion of the piston is interrupted. But neither the
motion nor the stoppage of the inferential meter has any effect upon
the water delivery, so that at times a large amount of water may
pass unrecorded. Another important mechanical difference is that the
motion of a piston meter should be slow, while that of the inferential
wheel is, and must be, rapid; this has much to do with their relative
durability.
Fig. 603 is a perspective view of the _Worthington water meter_, the
details of which are shown in the Figs. 604 and 605, the recording or
“dial” mechanism is also shown in Fig. 606.
The internal arrangement of the meter is shown in longitudinal section,
Fig. 604, and the transverse section, Fig. 605, on the opposite page.
[Illustration: FIG. 606.]
The plungers, AA, are closely fitted into parallel rings. The water
passes through the inlet and port I, and is admitted under pressure
into chamber, D, at one end of each plunger alternately, while the
connection is made between the chamber at the other end of the outlet.
Thus, the plunger in moving displaces its volume, discharging it
through its outlet. The arrangement is such that the stroke of the two
plungers alternates, the valve actuated by one admitting pressure to
the other. The plungers are brought to rest at the end of the stroke by
the rubber buffers, EE. One plunger imparts a reciprocating motion to
the lever, F, which operates the counter movement through the spindle
and ratchet gear as shown. Thus, it will be seen that the counter is
arranged to move the dial pointers once for every four strokes or
displacements, and that water cannot pass through the meter without
registration, for, in order to pass through, it must be displaced by
the plungers, and, therefore, recorded by the movement of the lever and
counter mechanism; nor can there be an over-registration, because the
plungers cannot move without displacing the fluid.
_To read the dial._ The counter usually registers in cubic feet, one
cubic foot being 7.48 gallons U. S. standard. When desired for special
services, counters are furnished reading in U. S. gallons, Imperial
gallons, and Hectolitres. This counter is read in the same way as the
registers of gas meters.
The following example and directions may be of use to those
unacquainted with this method:
[Illustration: FIG. 607.]
If the pointer is between two figures, the smaller one must invariably
be taken; suppose the pointers of the dial stand, as shown in Fig. 606;
starting at the dial marked 10 cubic feet, we get the figure 4; from
the next marked 100 cubic feet, the figure 7; from the next marked
1,000 cubic feet, the figure 8, and from the next marked 10,000 cubic
feet, the figure 6; the reading is 6,874 cubic feet. The pointer on
the 100,000 cubic foot dial being between the 0 and the 1 indicates
nothing. By subtracting the first reading taken from that taken at the
next observation, the consumption of water for the intermediate time is
obtained.
_A steam trap_ is an apparatus to remove the water of condensation from
steam pipes for heater coils and radiators without permitting steam to
escape; the steam trap is also used to remove the water of condensation
or entrained water caught in steam separators, located near the steam
engine in the connecting pipes between the engine and boilers.
The problem of saving the water of condensation without allowing the
escape of steam is a difficult one, in view of the early wear of the
valves and the valve seats.
Fig. 607 represents the Anderson improved steam trap. This trap shows
at all times what it is doing by the position of the water in the glass
gauge attached to the side of the trap and in front. The water of
condensation enters at the upper right-hand side, A, Fig. 608, where
all scale and dirt from the pipes are caught in the settling chamber
which contains a strainer. This strainer can be lifted out with its
contents of dirt and scale and replaced in a few moments by unscrewing
the plugs, shown in Fig. 607 just above the inlet. The discharge is
connected at the lower left-hand side. The bonnet which contains the
valve float and lever can be removed without breaking any pipe joints,
or the valve and seat may be removed by simply unscrewing the cap, H,
at the lower left-hand side without disturbing the bonnet at all. It
will be understood that this trap does not dump, but the discharge of
water is regulated by a ball float and valve, hence there are really
but two working parts to this trap, viz.: the ball float and valve.
Water is permitted to pass this trap as fast as it comes along, and no
considerable quantity ever accumulates within this trap at any one time.
[Illustration: FIG. 608.]
The sectional view, Fig. 608, gives a fair idea of the interior of this
trap, being a longitudinal section on center line. The by-pass valve,
C, so-called, is not a valve, but is simply a threaded stem and is
used to hold up the float in emptying the trap. To blow out the trap
this by-pass is screwed in as far as it will go without forcing, same
motion as in closing a globe valve. When the water has been discharged,
this by-pass is unscrewed to its former position, which permits the
float to drop, closing the valve when the reservoir fills with water,
to its normal position.
With three inches of water in the glass the valve is closed and sealed
so that no steam can escape. The dotted line represents the water
level. The sediment chamber, E, prevents dirt and scales in the pipes
from getting into the valve.
The ball float is made of seamless copper with heavy bands to prevent
the ball from collapsing under high pressure. These traps work on all
pressures from 150 pounds pressure down, and are also made for higher
pressures in special cases—will work against back pressure and with
exhaust steam alone—are made in seven sizes, _i.e._, from 1/2 inch to
2-1/2 inches, inclusive.
TOOLS
VALVES
AND PIPING
[Illustration: FIG 609.—See page 348.]
TOOLS.
The implements described hereafter are called “hand-tools” to
distinguish them from machine-tools. _A portable tool_ is a tool or
machine-tool which can be taken from place to place, for example a
riveting machine.
[Illustration: FIG. 610.]
_Tool_, the word, comes probably from toil, signifying the thing with
which one toils or labors, a hammer, file or wrench; a tool never
ceases to be a tool, _i.e._, something which is applied directly to the
work; generally tools in machine practice cut, abrade, like a file, or
strike—as a hammer; a tool is that which is brought to bear directly on
the work; again, it is any implement used by a craftsman at his work;
it is any instrument employed for performing, or aiding to perform,
mechanical operations by means of striking, penetration, separation,
abrasion, friction, etc.
Again in practical mechanics the word tool has a restrictive meaning;
a single device, as a chisel, crowbar or saw, or a very simple
combination of moving parts, as tongs, shears, pincers, etc. These
latter for manual use, are always called tools, although embodied in
the strict technical definition of machine.
Such machines as are used in shaping materials in the construction of
the parts of other machines, and also many of those which perform work,
such as boring, planing, riveting, etc., formerly only done by hand,
and still performed manually to a greater or less extent, are nearly
always called machine tools; the term, engine tool, is more in accord
with general usage when referring to large and complicated machines.
_It is by his knowledge of the application of hand-tools and their
practical use, that the pump attendant is judged by those around him._
The skillful mechanic, who with many others, constructs a machine, may
be neglected, but one who skillfully operates the apparatus, seldom
fails of due credit and reward, hence these paragraphs are intended to
emphasize the importance of these more humble implements.
Fig. 610 represents _a pipe cutter_—a hand tool specially used for
cutting of wrought iron, steel or brass pipe. This tool consists of a
cast steel body, tapped in one end to receive the adjusting screw or
handle which also serves to rotate the tool when applied to a pipe.
The cutting is generally effected by a hardened cast steel cutter with
cutting edges having angles of about 60° like a V thread; an enlarged
form of this cutter is shown in the engraving.
[Illustration: FIG. 611.]
Fig. 611 shows _a ratchet drill_; this is a tool in which the rotary
motion of the drill is derived from a ratchet and pawl actuated by a
lever or handle. There are various forms of this class of tools. This
one is the “Packer ratchet.” The thread for adjusting or feeding the
drill is protected from chips and dirt by a sleeve which covers the
shank.
The center is of tempered tool steel as well as the ratchet and pawl.
The socket is usually made square.
_In cutting larger sizes of pipes_ sometimes a special cutting-tool
is introduced in place of the circular cutter to accomplish the more
difficult work; in shop practice it is customary to cut the large sizes
of pipe in a lathe or screwing machine.
[Illustration: FIG. 612.]
[Illustration: FIG. 613.]
[Illustration: FIG. 614.]
The three tools shown on this page are designed to prepare the pipe
for the reception of the threaded end of the pipe to be joined. The
upper one, Fig. 612, is _a reamer_ used to enlarge a hole, or to round
up one that has been drilled or cut with a chisel, to prepare it for
tapping. The lower, Fig. 614, is _the tap_ which cuts the thread. The
middle, Fig. 613, is a _combined drill and tap_ which is operated by a
ratchet and is used to drill and tap a hole _in water pipe_, etc., at
one operation.
“_Tapping_” is the process by which the thread is formed in the
interior of a hole, and is done with a tap; _screwing_ is the reverse
process by which the thread is formed on the outside of a cylindrical
surface, as a pipe or round bar of iron.
_A tap consists of an external screw_ of the required size, formed of
steel and more or less tapered, part of the thread being cut away by
longitudinal grooves in order to present a series of cutting edges. By
screwing into a nut in the manner of an ordinary bolt this tap forms
the thread required.
_Plug-taps_ are usually made in sets of three. The first, called _the
entering tap_ or taper tap, generally tapers regularly throughout its
length; the second, or _intermediate tap_, sometimes tapers, but is
usually cylindrical with two or three tapering threads at the end; the
third, called the plug-tap or _bottoming-tap_, is always parallel, with
the full thread carried to the end.
[Illustration: FIG. 615.]
[Illustration: FIG. 616.]
Fig. 615 shows _a crow_. This is used to hook underneath a pipe and to
support and feed a ratchet drill in cutting a hole. The sliding head
is fastened by a double ended gib key which secures it in any desired
position. _A swivel bench vise_ is shown in Fig. 616. This tool has
cast steel jaws with a wrought iron slide and is attached to the bench
with a screw so that it may be turned in any position.
_A pipe vise_ is shown in Fig. 617. This is mounted on a journal
bearing so that it may be clamped in any position from a horizontal to
a perpendicular.
[Illustration: FIG. 617.]
_The pipe vise is especially a bench tool_; it is designed to “grip”
pipes of various sizes while they are being threaded, cut off or
otherwise operated upon.
_A parallel_ or ordinary bench vise will only grip a pipe on two
opposite sides, and, if tightened, the strain will easily collapse it,
owing to its hollow form; but a pipe vise is so made that it presses
upon four points, as the jaws or holding portions are formed V shaped,
instead of parallel.
Some pipe vises are formed of two pivoted discs instead of jaws, having
semicircles or recesses, which fit all diameters of pipes up to two
inches, and bear on the outside of the pipe all around.
It is an improvement to have the upper portion of the vise hinged at
one side, and fixed with a pin or collar at the other, as by opening
the jaws it renders more convenient the removal or insertion of the
pipe to be operated upon.
The upper Fig. 618 on page 342 represents an indispensable tool for
cutting pipe threads by hand; one handle—of which there are two—is
shown in the figure immediately beneath _the pipe stock and die_,
which is the familiar name of the combination. The _guard_ in the
illustration is thrown open to allow the _die_ to be removed or
exchanged. Fig. 620 represents the latter; solid steel dies are
commonly used, but _adjustable dies_ are made. Figs. 621 and 622 are
_bushings_ to fit in the end of the stock to guide the pipe; there is
one bushing for each size of pipe.
Fig. 623 shows a _nipple-holder_ which is used to hold short pieces
of pipe by the thread upon one end, while the die is applied to cut
a thread upon the other end. This tool is generally used in a pipe
cutting machine, which is operated by power, but it can also be held in
a common vise.
NOTE.—The die may be centered on the nipple described above by
_placing in the die stock_ a guide bushing that will easily ride
over the nipple holder. The thread can now be cut until the die just
touches the nipple holder, and there will be practically no blank
space between the threads on the ends. After the die has been backed
off the nipple can be removed from the holder by unscrewing the
center with a monkey wrench. _A nipple holder should be made for each
size of pipe that is cut and threaded by hand._ A piece of pipe with
a coupling on its end may be used as an improvised nipple holder.
[Illustration: FIG. 618.]
[Illustration: FIG. 619.]
[Illustration: FIGS. 620-622.]
[Illustration: FIG. 623.]
Fig. 624 shows an extension _pipe tongs_; this tool may be adjusted to
fit a number of different sizes by manipulating the thumb screw, shown
in the cut.
[Illustration: FIG. 624.]
[Illustration: FIG. 625.]
Fig. 625 represents the _Trimo pipe wrench_. This name is an
abbreviation of the word Tremont from the street in Boston of that
name. It is adjusted to its work by a milled nut in the pivoted jaw;
the latter is brought into position at each stroke by a leaf spring
attached to the main lever. In the larger sizes the steel jaws are
removable or can be detached and replaced after being repaired.
The lower engraving, Fig. 626, is a _chain tongs_ with removable,
tool-steel jaws. The hard scale on the piping rapidly destroys the
sharp edges on these jaws so that they require frequent sharpening. The
links of the chain have a peculiar hook form so that they cannot slip.
[Illustration: FIG. 626.]
_A spanner_, shown in Fig. 627, is a special form of wrench, which
circles or spans around; generally used for twisting a circular-shaped
portion, provided with holes in its circumference.
[Illustration: FIG. 627.]
[Illustration: FIG. 628.]
_Screw or monkey-wrenches_ are those which have a movable jaw, so that
the tool may be adjusted to fit any sized nut within its compass; as
shown in Fig. 628. There are many designs of monkey-wrenches. The one
here represented is known as the “knife-handle” on account of the
identical construction of the handle of this wrench and that of a
pocket knife. It is strong and the shank is extra heavy so that it is
hardly possible to spring the jaws in fair use.
[Illustration: FIG. 629.]
_An interchangeable socket wrench_ is shown in Fig. 629. The handle is
much like a ratchet drill, having a pawl and ratchet wheel attached to
the sockets; these are for use upon various sizes of hexagon or square
heads, as represented by figures underneath the handle. Some of these
socket wrenches have forms of steel for insertion into the hole in the
ratchet by which different shaped and sized bolt heads and nuts may be
turned without changing the main socket.
_The word wrench_ which gives this term to the tools here described
is one of the strong words of the English language; wrench means,
primarily, “a violent twist or turn given to something,” hence, as
derived, almost any instrument that causes a twist or torsional strain
comes under this heading. A wrench is a tool used by hand to turn or
rotate other tools, nuts or bolts.
A wrench is specially designated according to its shape and of the jaws
or openings, as an open-end box-wrench, etc. If the opening is through
one end, it is termed _a single-ended wrench_; if it is in the middle,
_a double-ended_ or tap-wrench. If the recess is open, it is termed
_an open-ended wrench_; if closed, forming a square or hexagon opening
through the metal, _a box-wrench_. A solid wrench having a notched
angular recess in its end, so that any nut or bolt which will enter the
jaws can be grasped, is called _an alligator-wrench_.
_The hammer_ was probably the first tool used by mankind; hammers of
stone are found among the remains of antiquity, and these are still in
common use among barbarous races. The hammer is made in such a variety
of forms that it is almost impossible to classify it; it is named not
only for the use to which it is put, but after the trade-class which
uses it, as the machinist hammer, the blacksmith-hammer, etc.
The hammer is made of high-grade steel, carefully tempered head and
peen; the head is usually made cylindrical with slightly rounding face;
the eye of the hammer is the center opening through which the handle
is inserted. The peen of a hammer is the opposite end to the face, and
terminates in a rounded or wedge-shaped point.
NOTE.—In its use _the hammer should be grasped near the end of the
handle_, giving it a free arm swing, and carrying the head through
a nearly vertical plane. If the plane of the swing approaches a
horizontal the weight of the hammer will produce a twisting effort
on the fore-arm, which will be very tiresome. _The handle should be
grasped with only sufficient force to safely control the blow_.
[Illustration: FIG. 630.]
[Illustration: FIG. 631.]
[Illustration: FIG. 632.]
VALVES AND COCKS.
The word _valve_ comes from the Latin—_valva_—a leaf, fold or valve of
a door (as of a folding door).
A valve may act automatically so as to be _opened_ by the effort of a
fluid to pass in one direction and _closed_ by its effort to pass in
the other direction, as a clack valve; or it may be opened or closed by
hand or mechanism, as a screw valve or a slide valve. _In the glossary_
at the beginning of this work, the word has been carefully defined and
several illustrations have been given of various designs of the device
which have come into general use.
Valves are of several classes.
1. _Rotary_; such as _cocks_, _faucets_, _plug throttle-valves_.
2. _Lifting_; raised clear from the seat by power beneath; such as
_ball_, _conical_, _cup_, _safety_, _poppet_.
3. _Hinged_; such as _clack_, _butterfly_.
4. _Sliding_; such as the _slide_, ^D^, ^B^ and _box_.
5. _Spring_; such as _some forms of safety-valves_, Snifting and Relief
valves.
6. _Inverted-cup_; such as _quicksilver valve_, _air trap_, etc.
7. _Key_; such as those of the _organ_, _flute_, etc.
Other names are derived from peculiar shape, application, mode of
actuation, etc.
_A cock_ is a faucet or rotary valve usually taking its name from its
peculiar use or construction, as:—
Blow-off cock,
Cylinder-cock,
Feed-cock,
Four-way cock,
Gage-cock,
Oil-cock,
Self-closing cock,
Steam-cock,
Stop-cock,
Three-way cock,
Try-cock,
Water-cock, etc.
NOTE.—The above classification is that made by E. H. Knight, Civil
and mechanical Engineer, etc., and author of Knight’s Mechanical
Dictionary. He adds: “The heart is created upon the principles
of hydraulics, and is furnished with a valve. Harvey deduced the
circulation of the blood from Aquapendente’s discovery of the _valves
in the veins_.”
As may be judged by the preceding paragraphs, giving the names derived
from their mechanical and other uses of several only, of a great
many varieties of valves, it were vain to attempt a complete list of
these devices; it may be said however that the whole system of modern
mechanism would be, almost, if not quite, a failure, if they were not
used.
Hence, the student will do well to familiarize himself with the valve
movements sure to be found in every combination of industrial and
mechanical forces.
A few illustrations of the adaptation of valves of various designs to
useful purposes now follow.—
_A combined throttle and quick closing trip valve_ is shown in Fig.
609, page 336; this is made by Schutte & Koerting Co., Philadelphia;
this apparatus is designed to fill the requirements of _an emergency
shut-off; the valve is balanced_ and operates as stop and throttle. The
object of balancing the valve is to remove the strain from the spindle,
so that its operation can be effected quickly and with the least
effort. The piston above the valve is not tight fitting, and contains
_a small auxiliary or pilot valve_ attached to the spindle, which opens
in advance of the opening of the main valve; thus the pressure above
the piston and below the valve is equalized; little effort is now
required to lift the main valve, at the same time the pilot valve, E,
answers the purpose of a by-pass.
The several proportions are such that a slight over-pressure is
maintained above the piston to give the valve, at all times, a tendency
to close. This over-pressure should be but slight, and to regulate it
at will there is (besides the leak around the piston) _a separate steam
admission above the piston, regulated by the plug, C_.
Depending on the fit of the piston, this plug is opened more or less,
or entirely closed, when valve is first put in operation, and then
locked in that position.
Ordinarily the construction of this valve demands the application of a
screw-spindle to actuate it; _it is also made in angle form and can be
placed with spindle upward or horizontal_. In all positions, globe,
inverted and angle valves, steam must always enter above the disc,
viz., in the direction of the arrows.
[Illustration: FIG. 633.]
_The operation by lever is demanded when a valve is used as a quick
emergency shut-off_, either by hand or in connection with automatic
appliance of governor, electrical cut-off or auxiliary, steam, air or
hydraulic cylinder.
The valve itself is of the balanced form, except that in this valve
_the spindle carries at the bottom a small piston or sleeve, F_, shown
in the figure. The valve is locked open by moving hand lever up till
the catch on same engages with the lever, G, supported on the upright
bar.
The valve being then open, steam pressure acts on the area of the
piston, F, with continuous downward force, which will cause the valve
to close as soon as the latch is released. Thus, by connecting the
rod on the outer end of lever, G, with a hand lever, at any desired
location, the operation is had without effort and promptly.
_A pressure reducing valve_ is shown in outline and a side view in
Figs. 633 and 634; this is in effect a (Mason) pump pressure regulator
and it is applicable for fire, tank, elevator, air and water works
pumps, or any class of pumping machinery where it is necessary to
maintain a constant pressure. The regulator may be quickly adjusted to
any pressure desired by turning the key as shown in Fig. 633.
The especial feature of this regulator is that the pressure chamber
into which the water enters is entirely removed and separate from the
steam and all working parts.
The long cylinder at the bottom of the regulator is a dashpot, the
piston of which is connected with the main valve of the regulator,
thereby preventing sudden and violent “jumping” of the pump when the
pressure suddenly changes. These valves are made in all the pipe sizes;
those up to and including 2-inch of the best steam metal; the largest
sizes of cast iron, lined with steam metal. _The springs are made of
the finest tool steel, tempered._
[Illustration: FIG. 634.]
The Mason Regulator Co., Boston, are to be credited with the following
directions:
The regulator is placed in the steam pipe leading from the boiler
to the steam pump and as near the pump as possible. The connection
with the water system is made either from the tank or from the water
system, at some little distance from the pump. Brass pipe should be
used if possible, for this connection. The drip should be connected
to some pipe where there is no back pressure. The steam from the
boiler enters at the point marked “steam inlet from boiler,” and
thence through the passage, X, through the port, which is kept
open by the tension of the spring, 79, upon the auxiliary valve,
80. It continues down through the passage, Z, to the under side of
the differential piston, 70, and raises the valve, 16, so that the
boiler pressure is admitted to the pump through the passage marked
“steam outlet to pump.” This starts the pump, which continues in
motion until the required water pressure is obtained in the system
and acts through the connection marked “water pressure inlet” on
the diaphragm, 74. This diaphragm is raised by the excess of water
pressure, and carries with it the auxiliary valve, 80, which closes
the port for steam pressure. By the closing of this valve, the boiler
pressure is shut off through the passage, Z, from the differential
piston, 70, and the steam pressure from the boiler immediately
closes the main valve, 16, so that no more pressure is admitted to
the pump, which remains inactive until the water pressure in the
system drops below the normal joint and relieves the water pressure
in the chamber, O, which causes the auxiliary valve, 80, to open
again, and starts the pump as before described. The check valve, 71,
which is placed in the bottom of the piston, 70, allows the pressure
regulator to open easily, but stops the pump quickly. This is a great
advantage, as the pump will not start with a jump, the moment the
water drops. By changing the tension of the spring, 83, through the
key stem, 85, the amount of water pressure can be regulated.
[Illustration: FIG. 635.]
_Mason water reducing valve._ Fig. 635 is designed to reduce the water
pressure from the street water mains to a low pressure, for houses
and buildings. The body or valve portion is fitted with couplings, so
that it may be easily attached to a pipe. That part of the valve above
the diaphragm, and which comes in contact with the water, is made of
the best steam metal, thus preventing corrosion. The long spring case
is made of heavy iron pipe, at the end of which is an iron bracket,
suitably drilled, so that the valve may be securely bolted either to
the floor or to a beam overhead. The tension of the main spring is
adjusted by means of a small rod inserted in a nut at the end of the
spring case. The diaphragm is very strong and will hold several times
the pressure required. The working of this regulator is very simple.
The water enters through the inlet coupling, 45, and passes through
the chamber, 68, into the low pressure side of the regulator, the
valve, 43, being held open by the tension of the spring, 53. When the
low pressure has attained the desired limit, which is also felt in the
diaphragm chamber through the hole which communicates with the chamber,
68, it forces down the diaphragm and seats the valve, 43. When the
pressure again drops in the system, the diaphragm is forced up by the
spring, 53, and the valve, 43, again opens.
_An automatic throttle valve_ for a boiler feed pump is shown
perspective and outline in Figs. 636 and 637; this is a governor for
the pump, controlled by the relative pressures of steam and water. It
is known as _Mullin’s automatic controller_ and is made at Seattle,
Wash., and has the following features:
[Illustration: FIG. 636.]
It is simply a balance valve and differential piston; it is in a class
by itself, both as to its construction and operation in regulating feed
water pressure in connection with steam boilers.
[Illustration: FIG. 637.]
The initial steam pressure being on the ends of the valve, has access,
through the neck, to the full area of the piston, and will force it
into a position that gives the full valve opening, where it will remain
until overcome by water pressure from the pump, acting against the
opposite side, which is of reduced area.
It is necessary in operating this valve to have _an excess of water
pressure over the steam pressure_ in the boiler. The excess of the
water pressure is obtained by the reduction of the area of the water
side of the piston—thus to illustrate—if the total area were 10 square
inches, and the reduction was one inch or 10 per cent., it would
require that the water pressure should be 10 per cent. greater than
steam pressure, to give the same thrust on the piston, then until the
water has reached a pressure 10 per cent. in excess of the steam, the
valve would be held open, but thereafter it is held open only wide
enough to admit steam to the pump to keep up this 10 per cent. excess
pressure. Should the excess pressure attempt to rise above this, it
immediately forces the steam valve nearly shut, thus nipping the cause
of the rise, namely, too great a piston speed.
NOTE.—“In starting the pump, ‘stand by’ until it has caught suction,
and accumulated nearly the correct water pressure, now open the
valve on the pulse, or pressure pipe to the controller and open pump
throttle wide, thus giving the controller free action.
“Suppose the boiler pressure is 100 pounds, the water pressure will
be 10 per cent. higher or 110 lbs. Carrying an even fire, with
water at second gauge, feed valves properly set, the load suddenly
increases, which pulls steam down to 99 pounds, the water does not
remain at 110 lbs. as before, but is now 10 per cent. in excess of 90
lbs. or 99 lbs., thus in place of 10 lbs. excess water pressure there
is but 9 lbs., which means there will be less water delivered through
the feed valves, which will hardly ever have to be touched.
“Next the load will lighten—steam will rise, and the excess pressure
will automatically increase, thus restoring the water used at a time
when it was most necessary to lighten the feed to temporarily favor
the fire.
“Suppose the load continues light, with good fires, steam rises to
110 pounds, the water will rise to 10 per cent. more pressure or 121
pounds, thus automatically giving more pressure to ‘feed up’ on high
steam, and store away the heat that would be wasted by radiation,
absorption, or perhaps blowing off.”
The water pressure will vary only as the steam pressure varies, always
keeping the same per cent. of excess. The results are directly opposite
to what would or does occur where feed water is delivered at a stated
pressure. On a battery of boilers, during the cleaning of fires, the
closing of feed valves on one, two or more boilers, does not affect the
feed of those already set in the least, the pump will simply make less
strokes necessary to properly feed the others.
The regulating is done by the feed valves at the boilers; if it is
desired, all feeds may be closed, and the pressure will not rise, the
pump will stop; if its plungers need packing it will be detected by the
fact that the pump will creep, to keep up the required pressure. When
feed valves are once regulated to admit the required amount of water,
to replace the evaporation, _they may be marked_, and when in this
position, they, with an even steam pressure, will always admit the same
amount of water to the boilers.
It is understood that this valve is placed between the ordinary
throttle valve and the pump.
[Illustration: FIG. 638.]
[Illustration: FIG. 639.]
_The Bordo blow-off valve_ is shown in Figs. 638 and 639; it consists
of a brass or iron body which resembles the shell of a plug-cock,
but with this difference, it has a sharper taper than the regular
plug-cock; in this device the plug is usually made of brass—tinned on
the outside. In process of making and while hot a sheath of babbitt
metal or its equivalent is cast upon the plug; the metals amalgamate
and practically become one casting.
The parts of valve are as follows, 1, the body, 2, the plug, 3, the
packing and lifting gland, 4, the lifting cam, 5, lock-nut, 6, two
brass rings of equal size, with a special gasket between them—all as
shown in the engravings.
_The valve is operated_ with a wrench on the square of the plug. The
lifting gland when adjusted is permanently held by a lock-nut. By
releasing the lock-nut with the wrench and turning the gland to the
left, the plug is lifted so that it will turn easily. When the lock-nut
is moved up, the lifting cam (which couples the packing gland to the
plug) can be pulled out; the gland is then free to be removed for
repacking. In use the best method of handling is to open and close the
valve slowly—never with a jerk.
[Illustration: FIG. 640.]
_The tendency toward higher pressure_ steam boiler installation has
made apparent the need of a blow-off, like this one described,
made of strong material and correct in principle; in fact the high
steam pressures now carried have almost made a revolution in boiler
appliances.
The Fig. 640 represents two valves applied to the end of a blow-off
pipe. The valve next to the boiler is open at all times excepting
when the operating valve, next to the sewer is to be attended to for
repairs, etc.
_The table below is_ intended to correspond with the letters to be seen
in the illustration, Fig. 640.
TABLE.
====================================================================
Size | Diam.|Centre|Centre|Centre|Centre| Diam. | No. |Diam.|Thick.
in | of | to | to | to | to |of Bolt| of | of | of
Inches|Flange| Face |Bottom| Top |Bottom|Circle |Bolts|Bolts|Flange
+------+------+------+------+------+ | | +------
| A | B | C | D | E | | | | I
======+======+======+======+======+======+=======+=====+=====+======
1 |4-1/2 |2-1/2 |4-1/2 |4-1/2 |2-1/8 |3-1/4 | 4 | 1/2 |11/16
------+------+------+------+------+------+-------+-----+-----+------
1-1/4| 5 |2-3/4 |5-1/8 |5-1/4 |2-1/2 |3-3/4 | 4 | 1/2 | 3/4
------+------+------+------+------+------+-------+-----+-----+------
1-1/2| 6 |3-1/4 |5-7/8 | 6 |2-3/4 |4-1/2 | 4 | 5/8 |13/16
------+------+------+------+------+------+-------+-----+-----+------
2 |6-1/2 |3-3/4 | 7 |7-1/4 |3-3/8 | 5 | 4 | 5/8 | 7/8
------+------+------+------+------+------+-------+-----+-----+------
2-1/2|7-1/2 |4-1/4 |8-1/4 |8-5/8 | 4 |5-7/8 | 4 | 3/4 | 1
------+------+------+------+------+------+-------+-----+-----+------
3 |8-1/4 | 5 |9-1/2 | 10 |4-5/8 |6-5/8 | 8 | 5/8 | 1-1/8
------+------+------+------+------+------+-------+-----+-----+------
One cock of this pattern is usually employed, but to use two (as shown
in the figure) is the best practice especially for high steam service.
NOTE.—It will be easily understood that the B. O. is an abbreviation;
it stands for Bordo. The makers claim for the device that, 1, it will
not stick or jam, 2, it keeps it seat under pressure, 3, it has full
pipe area in ports, 4, it is easily adjusted to take up wear and, 5,
it opens and closes with a quarter turn and with a very short wrench.
PIPES, JOINTS
AND FITTINGS
[Illustration: FIGS. 641, 642.—See page 363.]
PIPES AND FITTINGS.
_A pipe_ was originally a wind instrument of music, consisting of a
_tube or tubes_ of straw, reed, wood or metal; in the literature of
hydraulics this wind instrument becomes “_a long tube or hollow body
of wood, metal, earthenware, or the like_; especially, one used as a
conductor of water, steam, gas, etc.”
_A pipe fitter_ is one who fits pipes together, or applies pipes, as to
an engine or pump. A pipe fitter uses all the tools already described
and in addition several others, as stretched lines, the spirit level
and plumb-bob; he also uses special devices to aid in special cases;
these are sometimes invented by himself and sometimes belong to “the
trade-lore” transmitted in the long and varied operations of every
successful shop. _A pipe fitting_ is a piece, as a coupling, a valve,
etc., used for connecting lengths of pipe or as accessory to a pipe.
_Joint_ comes from the word join and means the place or part where two
things or parts are joined or united as a joint in a pipe. See note
below.
Narrow surfaces make better and safer joints than wide ones; they are
more quickly repaired with file or scraper, and they are less liable to
catch dirt at the moment of making a joint. The limit of narrowness is
that required to resist strains that might crush the metal and spoil
the face of the joint.
Unless the joint is made metal to metal, fitting without any orifice,
the jointing material is always softer than the pipes or other things
to be joined. In this way the jointing need not have dead-true
surfaces, but, yielding under pressure, it adapts itself to the space
it has to fill. It must be dense enough and hard enough to resist all
the working strains and influences that are likely to act upon it. The
jointing of a steam pipe must resist the temperature of the steam, the
water it carries with it, the changes of temperature when the pipe
cools during intervals of work, and the strains due to the weight of
the pipe, and also the internal pressure of the steam. If it expands
differently from the metal in the pipe, it must be sufficiently elastic
to compensate for this expansion, otherwise it will leak each time the
pipes cool down.
NOTE.—In proportion as steam pressure gets higher joints are made
thinner and flanges smoother. In the past rough turning succeeded
chipping, rough filing followed with an application of the surface
plate, and finally the scraper was used to produce a dead-true
surface, which is now only cleaned and wet with heavy mineral oil to
withstand any pressure whatsoever.
[Illustration: FIG. 643.]
[Illustration: FIG. 644.]
[Illustration: FIG. 645.]
The joint should be always inside the line of bolts, and if any joint
material extends beyond, it would only help to support the flange in
case it should spring. This, of course, indicates faulty design, for
flanges ought to bear the strains of jointing without perceptible
spring. Male and female flanges are best for high pressures.
A very popular joint is made with a planed or turned surface and a
sheet of paper of the quality used to wrap bales of paper. This is
the last survival of the millboard. Rubbed over the flange with a
dirty hand and cut out with a penknife on a board, this is one of the
cheapest jointings known. This paper has no lumps or grit in it, and
if smeared with mineral cylinder oil it may be separated several times
before it is spoiled. It is largely used on the faced joints of small
engines and steam pumps. The mineral oil increases the life of the
paper when exposed to high steam. Sheet asbestos is better.
_Hydraulic joints for high pressure_ require greater rigidity than
those of steam, but they do not have to bear high temperatures. The
jointing material may be more or less plastic, such as leather, rubber
or gutta percha. It is generally inclosed in a groove in the flange,
and compressed by a projection fitting the groove, so that expansion
of the jointing is arrested and the space is completely filled. There
is no better principle for joints than this where packing is used
between flanges. At a pressure of three tons to the inch, every square
sixteenth of an inch must resist a power equal to twenty-six pounds;
the joint must therefore be non-porous.
[Illustration: FIG. 646.]
[Illustration: FIG. 647.]
[Illustration: FIG. 648.]
[Illustration: FIG. 649.]
[Illustration: FIG. 650.]
[Illustration: FIG. 651.]
[Illustration: FIG. 652.]
_There are compounds used for making joints_ on which the plastic
matter, which is subject to much change of volume between the liquid
and solid state, is mixed with a neutral substance, like sand, which,
combining mechanically with it, replaces from 90 to 95 per cent. of the
total mass, and reduces its shrinkage to an inappreciable quantity.
[Illustration: FIG. 653.]
Another class of joints is that into which the jointing material is
poured in a liquid state. Most of those liquids, such as lead, pitch,
putty, sealing-wax, beeswax, or clay, shrink when they dry or cool.
Others, like _Portland cement_ and certain metallic alloys, do not
change in volume. Others, again, like sulphur and plaster of Paris,
increase in volume in setting. These substances all vary in their
elasticity, qualities of density, hardness, and powers of resisting
heat, cold and moisture. The duty of a joint must, therefore, be well
considered before the material is chosen, after which the recess in
which it is to lie must be carefully designed so as to firmly hold the
material and with the least possible waste.
[Illustration: FIG. 654.]
_Kerosene_, from its solvent powers, will destroy joints of rubber
or of cements compounded with oils. Kerosene tanks are, therefore,
rust-jointed and calked. As kerosene does not dissolve anything that
is soluble in water or alcohol, kerosene casks are coated with glue
to make them tight. India rubber may be used as a kerosene joint if
inclosed like the hydraulic joint, and prevented from swelling. It is
then unable to absorb the liquid. But leather is very much better.
_In making up a piece of piping_ in which several fittings are quite
close together, each fitting is tightened separately; do not follow
the common practice of making up loosely at first and then tightening
all together by applying a wrench to the fitting farthest from the
main connection, as this process does not insure tight joints and the
intermediate fittings, nipples, etc., are subjected to an unnecessary
torsional strain.
The proper arrangement of pipe connections have already been alluded to
in Part One, page 222; it is a subject whose importance can scarcely be
magnified for if any difficulty is experienced in making a pump work
properly when first started, it will generally be found to proceed from
imperfect connections, and this remains true quite to the end of the
usefulness of the pump. By a careful study of the illustration above
mentioned, a good degree of attention will be repaid.
Figs. 641 and 642 represent pipes which are specially intended for
_mine pump columns_ or discharge pipes. They are made in sizes from six
inches to thirty inches outside diameter; they are of wrought iron,
lap welded and tested to a pressure of five hundred pounds to the
square inch; they are fitted with cast iron or steel flanges, bolts and
gaskets which face square with the center line of the pipe.
These flanges are shrunk on the pipe as shown in the figures, expanded
and flared inside.
Fig. 643 represents a male and female flange joint metal to metal
combined with and forming a part of the pipe; it is used for special
work and conditions. Fig. 644 is the usual screwed sleeve threaded
connection with right hand coupling. Fig. 645 is a much used male and
female _flange union_ screwed for the reception of standard wrought
iron pipe. Fig. 646 illustrates the common threaded malleable iron
union and Fig. 647 the plain light _malleable iron tee_.
NOTE.—Attention of the reader is directed to that part of the
Glossary in the opening pages of Part One which relates to pipe and
fittings as being closely related to this division of the work and
which may be considered as an introduction to what is now added.
[Illustration: FIG. 655.]
[Illustration: FIG. 656.]
[Illustration: FIG. 657.]
_Steam Pipe Lines._ These are constructed of cast iron or wrought iron
and used for conveying a supply of steam from the boilers to engines,
pumps, turbines and other machines driven by steam. Usually these lines
are built up with straight pipe and “fittings.” The names of the latter
are as follows: elbows; forty-fives (45°); tees; plugs; caps; reducers
(or bushings); nipples; valves; unions (with ground, perishable, and
flange joints); couplings (reducing and right and left); crosses;
special fittings, such as elbows and tees of a nominal size reduced
at some point to a smaller size to avoid the use of reducers; angle,
check, and gate valves, and plug cocks; lock-nuts.
NOTE.—Cast iron was formerly entirely employed for steam pipe, but
now it is never used for high pressures.
While lead and iron pipe have taken the place of the old log pipes
of former days for carrying water and sundry purposes, there are
still uses for which wooden pipe is better adapted than any of the
metal pipes; a new kind of wire wound wooden pipe has been made. Each
length is built up of staves, wound with galvanized steel wire under
tension. The sizes are made 2 to 8 inches internal diameter. The
staves are kiln-dried, 7/8 inch to 1-1/2 inch thick. Joints are made
with a male and female socket on the small sizes, and a sleeve and
butt joint on the larger sizes, 8-inch pipe of this type, wound with
No. 4 copper wire, has been tried, where acid water rapidly destroys
ordinary pipes, with excellent results. This pipe has been tested to
500 pounds pressure, it is lighter to handle and is not so liable to
burst as cast iron.
_The proper anchoring and supporting of large steam mains is
important._ It is preferable to allow the system to expand in the
proper direction without stress and at the same time avoiding
vibration. The illustrations will give an idea of the method used in
supporting pipes and allowing for expansion. Fig. 657 shows a wall
bracket upon which the rollers supporting the pipe and allowing for the
expansion and contraction are attached. Fig. 655 shows a bracket with
an adjustable single roll, which may be adjusted to suit the pitch of
the pipe at the same time allow the pipe to expand.
_Fig. 655 shows a bracket_ with one adjustable roll designed for main
steam pipes. This is an elaborate device but would be appreciated in
buildings where everything is wanted to make up a strictly first class
line of details.
Fig. 657 represents an extension of the same idea in which one bracket
is made to carry two lines of pipe smaller than the one shown in the
preceding illustration. Fig. 656 is a support made of one inch round
iron and answers every purpose where all of these designs of pipe
hangers permit of free expansion and contraction of the pipes.
It is bad practice to support the main steam pipes over boilers by
hangers from the building as the building may settle in a different
degree from the boiler hence the steam pipes are not properly
supported, _i.e._, they are either strained unnecessarily by the strain
upon the hangers or they are permitted to support themselves; it is
better to support them by iron props underneath, made by screwing a
flange upon the end of a piece of pipe of proper length and having a
wrought iron crotch with thread and nut for adjustment inserted in the
upper end.
The flange on the prop rests upon the boiler walls while the crotch
fits the pipe and by means of the nut any desirable elevation of the
steam pipe may be secured. For when the boilers settle as they will the
pipes and connections all settle together.
[Illustration: FIGS. 658-666.]
Fig. 648 shows the common wrought iron _right-hand sleeve coupling_ and
Fig. 649 a plain lock nut.
Fig. 650 shows _the bell and spigot connection_ commonly used for
joining cast iron water or soil pipes, the joint being formed by
pouring melted lead into the cavity inside the bell. The melted lead is
prevented from escaping by damming up the opening with a turn of oakum
at the bottom and fire clay at the top of the joint. After the lead
cools it is calked with a calking tool. Fig. 651 is similar to Fig. 643
only the latter has plain flanges with a gasket, A, B, inserted.
Fig. 652 represents an improvement on the union shown in Fig. 646.
It is known as _the Dart-union_. The improvement consists in the
substitution of a ball and socket joint made of composition brass or
bronze ground joint and enclosed within the malleable iron case; unions
are particularly desirable for inaccessible locations where it would be
next to impossible to reach the union to renew the gasket.
Fig. 653 is an extra heavy _beaded malleable iron tee_, while Fig. 654
shows a common threaded _cast iron pipe plug_.
The figures on page 366 are one half end views, divided on the center
line, of brass and iron tubing; they are reduced in size, but show
their relative thickness, from one eighth inch up to four inches
inclusive.
The “_Standard_” sizes are shown in Figs. 663 and 664.
The “_extra strong_” are represented in Figs. 658, 661 and 662.
The _double extra strong_ is shown in Figs. 659, 660, 665 and 666.
All “tubing,” including boiler tubes, is measured by the _outside
diameters_, while gas and steam pipe, including cast iron water pipe is
designated by the inside diameter.
NOTE.—The best way of jointing hydraulic pipes has been the
subject of much practical experiment. A gutta percha ring has been
universally adopted as the best means of preserving the joint
watertight. Modified form of this joint is made by casting a
projection on the pipe beyond the flange, the bell and spigot being
formed on this projection. The effect is to increase the depth and
the strength of the flange, without an increase of its section at the
junction between the flange and the pipe.
Much might be said regarding duplicate pipe systems, both for and
against. The general practice is coming to be that of subdividing
into units, while in smaller plants the duplicate system is used. The
service and conditions govern the method of piping, which should be
such in every instance as to prevent a shut down due to accident in
some part of the system.
All the fittings in the pipe system of a plant should be of the best
quality, and the piping for high pressures should be extra heavy to
withstand the test of time and usage. Water pipes, when of commercial
wrought iron, should be galvanized.
In laying out a line of piping or in replacing a portion of an existing
line _the measurements should be taken from center to center_ of the
various fittings; the allowance for the threaded part of the pipe can
be made after the center-to-center and over-all measurements have been
made and before the pipe is cut. Experience teaches what to allow
for the threaded part on different sizes of pipe. The accompanying
engraving gives an illustration of how the measurements on a pipe
system are made.
[Illustration: Pipe System Measurements.]
As, for example, A represents the distance, center-to-center, from
elbow to tee; B, from the starting place to center of elbow; C, the
distance, center-to-center, of the two elbows; D, from the starting
place to the center of the globe valve; E, the center of the globe
valve to the center of the tee, and F, from the center of the tee to
the center of the elbow.
G shows the center of the elbow to the center of the union; H, from
the center of the union to the center of the tee, and I, from the
center of the tee to the center of the elbow; J, from the center of
the elbow to the center of the coupling, and K, from the center of
the coupling to the final tee; all as indicated by the arrow heads
and crosses.
USEFUL NOTES
“_There are many fingers pointing to the value of a training in
science, as the one thing needful to make the man, who shall rise above
his fellows._”—FRANK ALLEN.
[Illustration: Ancient device using steam to lift a ball.]
“_The motto marked upon our foreheads, written upon our door-posts,
channeled in the earth, and wafted upon the waves is and must be ‘Labor
is honorable and Idleness is dishonorable.’_”—CARLYLE.
“_A heavy wager has been laid
That there are tricks in every trade._”
USEFUL NOTES
RELATING TO PUMPS AND THEIR MANAGEMENT
_It happens at times_ that a pump, with the full pressure against which
it is expected to work, resting upon the discharge valves, refuses
to lift water for the reason that air within the pump chamber is not
dislodged, but only compressed by the motion of the plunger. It is
well, therefore, to arrange for running without pressure until the air
is expelled and water follows. This is done by _placing a check valve
in the delivery pipe, and providing a waste cock in the discharge
chamber to be closed after the pump has caught water_. A stop valve is
also required for shutting off the back pressure when the pump can be
opened for examination of the valves.
* * *
If any difficulty is experienced in making a pump work properly when
first started, it will generally be found in leaks through _imperfect
connections_, or from the temporary stiffness to be expected in a new
machine, or perhaps leaky valves.
* * *
If, when standing at the suction end of a centrifugal pump, looking
over pump shell toward pulley, the top of shaft revolves from right to
left, or against the sun, _the pump is right hand_, and if from left to
right, or with the sun, _it is left hand_.
* * *
_A pump should be located in a convenient_ as well as a clean place.
It should be well set upon a suitable foundation, so that it may be
free from vibration or jar; this “note” applies to direct-acting,
self-contained pumps, as well as to others.
* * *
The economical operation of a pump depends, to a great extent, upon the
kind and condition of the packing in the stuffing-boxes and pistons,
its quality, adaptability to particular requirements, and the method of
placing it in the stuffing-boxes and plungers.
* * *
Almost all the stuffing-boxes on pumps are too shallow and the glands
too short. To keep a rod tight under these conditions the packing must
be of the proper size and quality, and it must be put in with a view to
securing the greatest possible degree of elasticity, so that the rod
may be kept tight with the least pressure on the packing.
* * *
To do this, it is best to select packing which will permit a number of
narrow rings to be used instead of a few wide rings. The rings next to
the bottom will become dry and hard before those next to the glands of
the box are half worn out. If a number of narrow rings are used, the
dry ones may be removed and duplicated by new ones and replacing the
rest of the packing in the stuffing-box. This method economizes packing
and secures a tight yet freely working rod.
* * *
When patent square packings are used, it makes less difference whether
the rings are narrow or wide, because the surface in contact with the
rod will be nearly continuous in either case.
* * *
When cutting packing rings, the length should be such that the ends do
not come together within 1/8 inch when put into the stuffing-box, and
the rings are put in to break joints, which prevents leakage through
them.
When inserting this packing, the rings are put in one at a time, using
a piece of hard wood to push them to the bottom of the stuffing-box and
firmly against one another. The stuffing-box should be filled as full
as it can be, and start the nuts on the studs by hand. Screw up the
nuts with the hand and then start the pump slowly. If leakage occurs
do not attempt to tighten the nut while the rod is in motion, and in
all cases tighten it only enough to stop the leakage. A slight leakage
at the water end is not harmful. A little cylinder oil and graphite
occasionally applied to the rod will tend to keep it smooth and bright,
which condition is favorable to the durability of the rod and of the
packing.
* * *
When cutting rings of packing for the water piston or plunger, the
rings should be 1/8 inch short, as previously described, page 372.
* * *
Packing should fit the grooves in solid pistons moderately tight, so
that the packing can be pushed into the grooves with the fingers.
The depth of the packing should be such that the piston will fit the
bore of the water cylinder snugly when first put in. If packing of
the proper depth cannot be obtained, it is better to have the grooves
turned to receive standard sizes of packing and not require special
sizes. Cutting hydraulic packing is a tedious job, consuming a great
deal of unnecessary time.
* * *
_It takes less power to feed into the bottom of a tank than it does
into the top_, on account of the weight of water in the tank. The
bottom of the tank holds up all the water except the column directly
over the opening of the delivery pipe, so that the additional pressure
on the pump is due only to the depth of water in the tank, not to the
size of the body, and it is impossible to feed into the top without
increasing the height of the column fully as much. It makes no
difference whether the height is due to the depth of the water inside
the tank or an additional length of pipe outside.
* * *
_The duty of the air pump is solely to get rid of the water and air in
the condenser._ It adds to the efficiency of the condensing apparatus,
and renders its operation continuous; its valve being thrown by the
action of its own piston, it must complete its stroke in length whether
the piston is moving in air, water or vapor.
_Pumps should be kept clean internally and externally._ In order to
keep a pump clean internally it must be inspected and oiled internally
at regular intervals the same as it is externally.
* * *
When pumps fail to work properly the difficulty is generally located in
one of three places, viz.: _the water end, the steam end or the suction
pipe_.
* * *
The several parts of the valve gear of a single cylinder pump _should
be marked when the pump works properly_, then any trouble due to the
slipping of the collars or tappets can readily be remedied; if the
nuts and set screws are kept tight, derangements occur only at long
intervals.
* * *
The principal difficulties encountered with steam pumps are not
generally due to improper steam distribution, but to wear, as may be
seen; hence by inspecting pumps at regular intervals many unpleasant
occurrences and accidents can be avoided.
* * *
_The steam pipe leading to a pump_ should be so arranged that the
water of condensation, while the pump is idle, may not pass through
the steam chest and cylinders, and wash off the lubricating oil. Drip
cocks should be attached to steam pipes and all large pipes should have
separators and steam traps.
* * *
Pumps that are generally operated at moderately high speeds and with
high lifts may be made to work more smoothly by placing a _vacuum
chamber on the suction pipe_.
* * *
_Valves in the suction pipe_ should have the stems carefully packed
and kept tight; air leaks in valve stem stuffing-boxes are too often
overlooked.
* * *
_Stoppage of the suction pipes_ or chamber is generally indicated by a
jerky action and pounding of the plungers or water pistons, while a
dull thud at the ends of the stroke is more often due to a lack of air
in the air chamber, or when the speed is high, to a lack of capacity in
the air chamber.
* * *
_The steam ends of pumps_ require the same lubrication as the cylinders
and valves of engines. Intermittent lubrication is never to be
recommended even for slow running pumps. Sight feed oil cups are always
preferred.
* * *
_A sight feed lubricator_ connected to the steam pipe below the
throttle or to the steam chest is _automatic in its operation_. All
that is necessary is to fill it. When the speed increases the feed
increases and when the pump stops the feed stops. An oil hand pump is
also desirable to introduce a mixture of oil and graphite, about 10 per
cent. of graphite.
* * *
_The water end stuffing-boxes of a pump_ may be lubricated by putting
a heavy grease on the piston rods, or good cylinder oil may be used
when grease is not at hand. _Some of the grease works into the
stuffing-boxes_ and furnishes better lubrication than can be obtained
by the water alone. Care must be used not to use too much oil as it
must not go beyond the stuffing-boxes and contaminate the water.
* * *
When a pump works properly under high pressures and fails to work under
low pressures, the difficulty is generally found _in the lift of the
valves_.
* * *
_When the water end of a pump_ is known to be in good condition failure
to run properly will in all probability be discovered _in the steam
end_, and in single cylinder pumps the fault is generally caused
by clogging of the auxiliary valves and ports. Sometimes pieces of
packing break off and get into these small ports, thus shutting off the
admission or release of steam.
* * *
_When one side of a duplex pump_ makes a quick stroke it indicates
either that the stuffing-box gland of the opposite side is too tight
or that the packing in the cylinder of the side making the quick
stroke is wearing out or has, perhaps, given way. A broken discharge or
suction valve will also cause a “jerky“ motion of the pistons.
* * *
Pumps should be examined frequently in order _to know what parts are
beginning to wear_ and how fast the wear is taking place. When this
is done the worn parts can, in the majority of cases, be taken out
and replaced by new ones before they give out entirely, thus avoiding
delay, but what is better, _duplicated parts kept on hand_ ready at a
moment’s notice.
* * *
The regular inspection _of the screen in the separating chamber_ in the
suction pipe renders frequent inspections of the interior of the pump
unnecessary, the inspection previously alluded to is generally easier
and more quickly done.
* * *
_Considerable wear can and frequently does take place in a pump_ in the
course of six months, and for this reason it is advisable to inspect
the interiors at shorter intervals, say four months for general service
pumps and once in three months for boiler feed pumps. More frequent
inspections should be made when handling dirty water.
* * *
_When a pump has to run faster one week than the week previous_ in
order to supply approximately an equal volume of water, the plungers
and valves should be examined, because such behavior indicates leakage.
* * *
_The sight feed lubricator should be filled in the morning_ so as to
be empty by night, thus permitting the water to be drained out without
wasting oil. Draining the delivery valve chest will also drain the
delivery pipe up to the check valve if those pipes are above the chest
and without water seals in them. If this pipe is arranged below the
pump, then separate drain cocks should be provided and should be placed
at the lowest positions in the piping.
* * *
_When a pump fails to start after standing for some time_ it should be
primed by filling the barrel with water and starting the pump slowly.
If after priming it fails to raise water, the suction pipe should be
examined and also the plungers and the valves. If the plunger packing
has become dry and hard, merely filling the water end with water will
not at once remedy the trouble because the packing must be thoroughly
soaked before it will work properly.
* * *
_Pumps should be packed with the same care and consideration as is used
with the best steam engines._ The rods should be packed just tight
enough to prevent leakage, and the packing renewed often enough to keep
it soft and pliable, in which state it readily absorbs oil. Old packing
will upon examination be frequently found full of sand and small
particles of grit.
* * *
_Metallic packings_ are now extensively used on steam piston rods and
upon the rods of air pumps.
* * *
_When priming and draining a pump_ the air cock in the air chamber
should also be opened. The drain and cylinder cocks at the steam end
should be opened before closing the throttle; the steam should be shut
off at the boiler when stopping at night so as to drain the entire pipe.
* * *
_Pumps that are exposed to low temperatures in winter_ should be
provided with removable drain plugs or drain cocks for emptying the
cylinders and valve chambers of water and also allowing the water to
flow out of the suction pipe.
* * *
_The friction in pipes_, whether of cast iron, steel or copper, depends
upon the internal smoothness of the pipe and the velocity of the
water, as well as the number and kind of ells, tees and valves in the
pipe. Wrought iron lap welded pipe, for steam, is preferable to either
cast iron or copper. It is smoother internally than cast iron, and is
lighter and costs less than copper, and is much stronger and safer than
either.
* * *
It may be said when an engine is run without a condenser the steam
with which the cylinder is filled at the end of the stroke _has to be
forced out against the pressure of the atmosphere_, about 15 pounds to
the square inch. It is possible from the nature of steam to remove the
atmospheric pressure with a decided gain in almost all cases.
* * *
_One pound of steam at atmospheric pressure_ occupies 1,642 times
as much room as it does in the state of water. If, therefore, when
the stroke has been completed, and we are ready for the piston to
come back, we inject a little cold water into the spent steam, it
will condense to about one 1600th of its volume, and leave a vacuum
into which the piston can return without having to force back the
atmosphere. This is the way the earlier vertical engines were run, the
condensation taking place in the cylinder itself, and, moreover, the
vacuum was all that made the engine operative, for the steam carried
was but little above atmospheric pressure.
* * *
_The velocity of water entering a suction pipe_ depends upon two
things, the vacuum in the pipe and the vertical lift of the water.
The longer the suction pipe, vertically, the greater the frictional
resistance to the flow of water; the flow of water through small
discharge pipes should not exceed four hundred feet per minute, and for
large pipes five hundred feet per minute.
* * *
_A locomotive-boiler compound._ The lines of a certain great R. R.
traverse a country where the water is very hard and they are compelled
to resort to some method of precipitating the lime that is held in
solution. After many tests and experiments they have made a compound
and use it as follows: in a barrel of water of a capacity of fifty
gallons they put 21 lbs. of carbonate of soda, or best white soda ash
of commerce, and 35 lbs. of white caustic soda; the cost, per gallon,
is about 2-1/2 cents. The compound is carried in this concentrated
form, in calomine cans on the tender of each locomotive. A certain
amount, according to the necessities of the case, is poured into the
tender at the water tank at each filling. This amount is determined
by analysis, and varies all the way from two to fifteen pints for two
thousand gallons of water. The precipitating power of this compound
may be taken roughly at 2/3 of a pound of the carbonate of lime, or
equivalent amount of other material, per pint of the compound. On their
western lines where they are dealing with alkali waters and those
containing sulphates, the company use merely 60 pounds of soda ash to
a barrel of water. When the water is pumped into the boiler the heat
completes the precipitation and aggregation of the particles, and this
does away with all trouble of the boiler or injector tubes clogging up.
* * *
It has been recently determined by some German experimenters that
_sugar effects a strong action in steam boilers_; it has an acid
reaction upon the iron which dissolves it with a disengagement of
hydrogen. The amount of damage done increases with the amount of sugar
in the water. These results are worthy of note in sugar refineries and
places where sugar sometimes finds its way into the boilers by means
of the water supplied. The experiments in question also show that zinc
is strongly attacked by sugar; copper, tin, lead and aluminium are not
attacked.
* * *
_White oak bark, used by tanners_, has an excellent effect on boiler
incrustations. It may be used as follows: Throw into the tank or
reservoir from which the boilers are fed a quantity of bark in the
piece, in sufficient quantity to turn the water to a light brown
color. Repeat this operation every month at least, using only half
the quantity after the first month. Add a very small quantity of the
muriate of ammonia, about one pound for every 2,000 gallons of water
used. This will have the effect of softening as well as disintegrating
the carbonate of lime and other impurities deposited by the action of
evaporation.
NOTE.—Care must be exercised in keeping the bark, as it becomes
broken up, from the pump valves and blow-off valves. This may be
accomplished by throwing it into the reservoir confined in a sack.
_Among the best samples of boiler compounds_ ever sent to the
laboratory for analysis were those found to be composed of:
Sal-soda 40 Pounds
Catichu 5 „
Sal-ammoniac 5 „
This solution was formerly sold at a good round figure, but since its
nature became more generally known, it is not found in the market, but
it is largely used, consumers putting it up in lots sufficient to last
a year or so at a time.
The above is strongly recommended by those who have used it, one pound
of the mixture being added to each barrel of water used, but after the
scale is once thoroughly removed from the boiler, the use of sal-soda
is all that is necessary.
* * *
_There are other evils sometimes inherent in hard waters_ above the
mere production of a crust. Some waters contain a great deal of soluble
magnesia salts, together with common salt. When this is the case there
is a great probability of corrosion, for the former is attacked by
steam at high pressure in such a way that muriatic acid fumes are
produced, which seriously corrode the boiler, and what is far worse,
passes with the steam into the engine, and sets up corrosion in the
cylinders and other delicate fittings with which the steam comes in
contact. All this can, however, be obviated by the removal of the
magnesia from the water.
* * *
_When water attains a high temperature_, as it does under increasing
pressure, ranging from 175° to about 420° Fahr., all carbonates,
sulphates and chlorides are deposited in the following order:
First. Carbonate of lime at 176° and 248° Fahr.
Second. Sulphate of lime at 248° and 420°.
Third. Magnesia, or chlorides of magnesium, at 324° and 364°.
It is to take advantage of this fact that mechanically arranged jets,
sprinklers and long perforated pipes are introduced into the interior
of a steam boiler; these tend to scatter the depositing impurities
and also to bring the feed water more quickly to the highest possible
temperature.
_Where fuel is expensive_ and pumps are used for continuous service
under high and unusually high pressures it is oftentimes advisable to
operate the pumps condensing. This may be done, when the pump lifts
water by suction, without a separate condenser by connecting the
exhaust pipe with the suction pipe, as shown in Fig. 667. Assume that
the pump has been working properly for from 3 to 5 minutes with the
valve _A_ nearly closed and the valve _B_ a little open, the valve
_A_ is now quickly closed and _B_ opened. In operating these valves
both hands should be used, so that they may be opened and closed
simultaneously.
[Illustration: FIG. 667.]
_So penetrating is water at high pressure_ that only special qualities
of cast iron will be tight against it. In the early days of the
hydraulic jack it was no uncommon thing to see water issuing like
a fine needle through the metal, and the water needle is said to
penetrate the flesh as readily as one of steel.
The engraving, Fig. 668, represents a novel device for _preventing the
bursting of water pipes by freezing_. This is simply an air chamber
placed in the horizontal part of the pipe, with the chamber on top
side so that the ice may expand into this chamber, and so its force is
expended upon the air instead of bursting the pipe.
This device also acts as an air chamber and prevents “water hammer.” It
is made by the Anti-bursting pipe Co., Pittsburg, Pa.
_When it becomes necessary_ to make a quick connection into a main
steam pipe without breaking joints, a saddle such as either of those
shown in Fig. 669 and Fig. 670 may be applied by simply cutting or
drilling a hole through the main steam pipe.
[Illustration: FIG. 668.]
_To make the joint_, the rough lumps should be filed off the outside
of the pipe and red lead rubbed on to mark the surface, to show when
the fit is properly made. Then lay on with a brush a thin mixture of
red lead and varnish and quickly screw the saddle in place. Such joints
seldom or never leak when allowed to thoroughly dry before use.
[Illustration: FIG. 669.]
[Illustration: FIG. 670.]
When it becomes necessary to cut square packing to reduce its depth,
place the packing in a vise, allowing the stock to be removed to
project above the jaws, as shown in Fig. 671. With the aid of a
draw-knife the work can be quickly and easily done. It is difficult
to cut the packing evenly. If the rings have an uneven bearing on the
bottom of the grooves leakage is likely to occur when the pump is first
started.
_The follower type of water piston_ can readily be packed without
removing it from the cylinder, providing rings of the proper depth and
length are at hand. The old packing rings can be removed with a packing
hook. Take the new ring and start one end with a soft stick, and push
the remainder of the ring firmly against the collar or flange at the
inner end of the piston, as shown in the engraving, Fig. 672. Arrange
the several rings so as to break joints.
_Method of packing a follower piston._ Coat the sides of the rings with
a thick paste of cylinder oil and _Dixon’s Flake_ graphite, which will
prevent the rings from sticking together.
[Illustration: FIG. 671.]
_Pump packing cannot be readily examined_ and is liable to fail at any
time, therefore several rings, cut to the proper length, should be kept
on hand. This may be easily done by making a pattern ring, which is
nothing more or less than a ring of packing which has been fitted into
the piston and is known to be of the proper length. The extra rings can
then be cut at odd times, and when occasion demands it the water piston
can be packed very quickly and the pump started.
Care should be taken when about to pack a boiler feed pump or other
pump subjected to high pressure to see that the cylinders are relieved
before loosening the cylinder head bolts. This may be accomplished by
closing the valve in the delivery pipe, and also in the suction pipe;
if the pump receives water under pressure, open the air cock on the air
chamber and cylinder cocks.
[Illustration: FIG. 672.]
_Pump slip or slippage_ represents the difference between the
calculated and the actual discharge of a pump, which is generally
expressed as a percentage of the calculated discharge. Thus, when the
slippage is given as fifteen per cent. it indicates that the loss due
to slip amounts to fifteen per cent. of the calculated discharge.
Slippage is due to two causes, the time required for the suction and
discharge valve to seat, due to excessive speed. When the piston
speed is so high that the water cannot enter the pump fast enough to
completely fill the cylinder only a partial cylinder full of water is
delivered at each stroke. High speeds also increase slippage, due to
the seating of the valves.
_Graphite as a lubricant_ is almost without a rival. It is one of the
forms under which carbon appears in nature; it is also known under the
name of _plumbago_ and _black lead_; it is soft and oily to the touch;
it is a conductor of electricity; it is a lubricant that allows pipe
joints to be screwed up to the tightest possible fit. Graphite remains
upon the threads preventing rust, and it so preserves its peculiar
properties that pipe can be unscrewed without effort eight or ten years
after the joints have been made.
_It is difficult to lift hot water by suction, but not everyone can
explain the cause_; the reason is as follows:
[Illustration: FIGS. 673 AND 674.]
In Fig. 674, let A be a vessel in which a vacuum exists, and let it
communicate by a tube, as shown, to the lower vessel containing water.
The pressure of the atmosphere upon the surface will force the water
up into the pipe until the column is high enough to exert a pressure
per square inch equal to that of the atmosphere. A cubic inch of water
weighs about 1/28 of a pound, so that it will take 28 cubic inches to
weigh a pound, or a column 28 inches high to exert a pressure of one
pound per square inch. The atmospheric pressure is 14.7 pounds, or to
avoid fractions, say, 15 pounds. This pressure would then support a
column (15 × 28)/12 = 35 feet high; that is, the column _a-c_ in Fig.
674 would be 35 feet in height. Attach a gauge at or above the top,
_a_, of a column, and it will indicate a perfect vacuum; if the gauge
were attached 28 inches below _a_, it would indicate a pressure of one
pound above absolute zero, or a vacuum of 15-1 = 14 pounds; and if the
gauge were moved further downward, it would indicate an increasing
pressure, that is, a diminishing vacuum, at the rate of one pound for
every 28 inches of the water column above it, until at the level of the
water in the tank the pressure would be 15 pounds absolute, and the
vacuum would be zero.
Now, suppose the pipe to be lowered until the distance from the bottom
of the vessel, A, to the water level, _c_, is 21 feet. In that case we
will have the pressure of the atmosphere (15 pounds) forcing the water
up into the vessel, and the column 21 feet high, or (21 × 12)/28 = 9
pounds, opposing it. The difference, 15-9 = 6 pounds, is available to
force the water into the chamber. This arrangement is shown in Fig.
673, where A is a pump cylinder; then the difference in pressure, 6
pounds, lifts the valve, and the water enters the pump chamber with
a velocity due to that pressure. In order to insure smooth and quiet
running of the pump, it is necessary to keep the speed of the piston
inside of the velocity with which the cylinder would fill under this
pressure, reduced by the friction of the water, the pressure required
to lift the valves, etc.
But this supposes that there is a perfect vacuum in A, and we cannot
realize this in contact with hot water. Water at any temperature will
boil unless it is under a pressure equal to or greater than that
corresponding with the temperature. Water at 60 degrees F. will boil if
the pressure upon its surface is reduced to a quarter of a pound per
square inch, and in the case shown in Fig. 674, it would boil and fill
the space A with steam at that absolute pressure.
NOTE.—Water at 170 degrees F. will boil if its pressure is reduced
below 6 pounds absolute, and if the water were at this temperature
in Fig. 673, the cylinder, A, would be filled with steam at 6 pounds
pressure; and this added to the 9 pounds pressure of the column would
completely balance the atmospheric pressure, and the water would not
rise above the level, A.
TABLES AND
DATA
[Illustration: FIG. 675.]
TABLES AND DATA.
_Miner’s Inch Measurement._ _The term miner’s inch_ is of California
origin, and not known or used in any other locality, it being a method
of measurement adopted by the various ditch companies in disposing of
water to their customers. The term is more or less indefinite for the
reason that the water companies do not all use the same head above the
center of the aperture, and the inch varies from 1.36 to 1.73 cubic
feet per minute each, but the most common measurement is through an
aperture 2 inches high and whatever length is required, and through
a plank 1-1/4 inches thick, as shown in the engraving, Fig. 675. The
lower edge of the aperture should be 2 inches above the bottom of the
measuring box, and the plank 5 inches high above the aperture, thus
making a 6-inch head above the center of the stream. Each square inch
of this opening represents a miner’s inch, which is equal to a flow
of 1-1/2 cubic feet per minute. Time is not to be considered in any
calculation based upon a miner’s inch measurement.
_Explanation of Weir Dam Measurement._ Place a board or plank edgewise
across the stream to be measured as illustrated in Fig. 676.
This plank will be supported by posts sufficiently strong to resist
the pressure likely to be brought upon it by the head of water which
will form in the pond above this temporary dam, saw out a gap in the
top of the dam whose length should be from two to four times its depth
for small quantities of water and longer for larger quantities. The
edges of this gap should be beveled toward the intake as represented.
The over-fall below the bottom of gap should be not less than twice its
depth, that is, twelve inches if the gap is six inches deep, etc.
Drive a stake above the dam at a distance of about six feet from the
face of the plank and then obstruct the water until it rises precisely
to the bottom of the gap and mark the water level on the stake.
Complete the dam so that all the water will be compelled to flow
through the gap and when the stream has assumed a regular flow mark the
stake at this new level.
Some would prefer to drive the stake with its top precisely level with
the bottom edge of gap in dam so that the depth of water in stream may
be measured with a rule or steel square placed upon top of this stake
at any time after the flow of water has reached its average depth over
dam. However the marks upon the stake are preferred by most experts.
After the stake has been marked it may be withdrawn and the distance
between the first and last marks gives the theoretical flow according
to the table, page 391.
[Illustration: FIG. 676.]
_Measurement in an open stream by velocity and cross section._ Measure
the depth of the water at from 6 to 12 places across the stream at
equal distances apart. Add together all the depths in feet and divide
by the number of measurements made; this will be the average depth of
the stream, which, multiplied by its width, will give its area or cross
section. Multiply this by the velocity of the stream in feet per minute
which gives the cubic feet per minute of the stream.
Cubic Feet of water per minute that will flow over a Weir one-inch wide
and from 1/8 to 20-7/8-inches deep.
------------+-------+-------+-------+-------+-------+-------+------
INCHES | 1/8 | 1/4 | 3/8 | 1/2 | 5/8 | 3/4 | 7/8
----+-------+-------+-------+-------+-------+-------+-------+------
=0=| .00 | .01 | .05 | .09 | .14 | .19 | .26 | .32
=1=| .40 | .47 | .55 | .64 | .73 | .82 | .92 | 1.02
=2=| 1.13 | 1.23 | 1.35 | 1.46 | 1.58 | 1.70 | 1.82 | 1.95
=3=| 2.07 | 2.21 | 2.34 | 2.48 | 2.61 | 2.76 | 2.90 | 3.05
=4=| 3.20 | 3.35 | 3.50 | 3.66 | 3.81 | 3.97 | 4.14 | 4.30
=5=| 4.47 | 4.64 | 4.81 | 4.98 | 5.15 | 5.33 | 5.51 | 5.69
=6=| 5.87 | 6.06 | 6.25 | 6.44 | 6.62 | 6.82 | 7.01 | 7.21
=7=| 7.40 | 7.60 | 7.80 | 8.01 | 8.21 | 8.42 | 8.63 | 8.83
=8=| 9.05 | 9.26 | 9.47 | 9.69 | 9.91 | 10.13 | 10.35 | 10.57
=9=| 10.80 | 11.02 | 11.25 | 11.48 | 11.71 | 11.94 | 12.17 | 12.41
=10=| 12.64 | 12.88 | 13.12 | 13.36 | 13.60 | 13.85 | 14.09 | 14.34
=11=| 14.59 | 14.84 | 15.09 | 15.34 | 15.59 | 15.85 | 16.11 | 16.36
=12=| 16.62 | 16.88 | 17.15 | 17.41 | 17.67 | 17.94 | 18.21 | 18.47
=13=| 18.74 | 19.01 | 19.29 | 19.56 | 19.84 | 20.11 | 20.39 | 20.67
=14=| 20.95 | 21.23 | 21.51 | 21.80 | 22.08 | 22.37 | 22.65 | 22.94
=15=| 23.23 | 23.52 | 23.82 | 24.11 | 24.40 | 24.70 | 25.00 | 25.30
=16=| 25.60 | 25.90 | 26.20 | 26.50 | 26.80 | 27.11 | 27.42 | 27.72
=17=| 28.03 | 28.34 | 28.65 | 28.97 | 29.28 | 29.59 | 29.91 | 30.22
=18=| 30.54 | 30.86 | 31.18 | 31.50 | 31.82 | 32.15 | 32.47 | 32.80
=19=| 33.12 | 33.45 | 33.78 | 34.11 | 34.44 | 34.77 | 35.10 | 35.44
=20=| 35.77 | 36.11 | 36.45 | 36.78 | 37.12 | 37.46 | 37.80 | 38.15
----+-------+-------+-------+-------+-------+-------+-------+------
Example showing the application of the above table
Suppose the Weir to be 66 inches long, and the depth of water on it
to be 11-5/8 inches. Follow down the left hand column of the figures
in the table until you come to 11 inches. Then run across the table
on a line with the 11 until under 5/8 on top line you will find
15.85. This multiplied by 66, the length of Weir, gives 1046.10, the
number of cubic feet of water passing per minute.
FRICTION-LOSS IN POUNDS PRESSURE, FOR EACH 100 FEET OF LENGTH IN
DIFFERENT SIZE CLEAN IRON PIPES DISCHARGING GIVEN QUANTITIES OF WATER
PER MINUTE. ALSO VELOCITY OF FLOW IN PIPE, IN FEET PER SECOND.
_G. A. Ellis, C. E._
----------+-----------------------------+-----------------------------
Gallons | 1/2 Inch. | 3/4 Inch.
discharged|--------------+--------------+--------------+--------------
per |Veloc. in Pipe| Friction Loss|Veloc. in Pipe| Friction Loss
minute. | per second. | in pounds. | per second. | in pounds.
----------+--------------+--------------+--------------+--------------
5 | 8.17 | 24.6 | 3.63 | 3.3
10 | 16.3 | 96.0 | 7.25 | 13.0
15 | .... | .... | 10.9 | 28.7
20 | .... | .... | 14.5 | 50.4
25 | .... | .... | 18.1 | 78.0
----------+--------------+--------------+--------------+--------------
----------+-----------------------------+-----------------------------
Gallons | 1 Inch. | 1-1/4 Inch.
discharged|--------------+--------------+--------------+--------------
per |Veloc. in Pipe| Friction Loss|Veloc. in Pipe| Friction Loss
minute. | per second. | in pounds. | per second. | in pounds.
----------+--------------+--------------+--------------+--------------
5 | 2.04 | 0.84 | 1.31 | 0.31
10 | 4.08 | 3.16 | 2.61 | 1.05
15 | 6.13 | 6.98 | 3.92 | 2.38
20 | 8.17 | 12.3 | 5.22 | 4.07
25 | 10.2 | 19.0 | 6.53 | 6.40
30 | 12.3 | 27.5 | 7.84 | 9.15
35 | 14.3 | 37.0 | 9.14 | 12.04
40 | 16.3 | 48.0 | 10.4 | 16.1
45 | ... | ... | 11.7 | 20.2
50 | ... | ... | 13.1 | 24.9
75 | ... | ... | 19.6 | 56.1
----------+--------------+--------------+--------------+--------------
----------+-----------------------------+-----------------------------
Gallons | 1-1/2 Inch. | 2 Inch.
discharged|--------------+--------------+--------------+--------------
per |Veloc. in Pipe| Friction Loss|Veloc. in Pipe| Friction Loss
minute. | per second. | in pounds. | per second. | in pounds.
----------+--------------+--------------+--------------+--------------
5 | 0.91 | 0.12 | ... | ...
10 | 1.82 | 0.47 | 1.02 | 0.12
15 | 2.73 | 0.97 | ... | ...
20 | 3.63 | 1.66 | 2.04 | 0.42
25 | 4.54 | 2.62 | ... | ...
30 | 5.45 | 3.75 | 3.06 | 0.91
35 | 6.36 | 5.05 | ... | ...
40 | 7.26 | 6.52 | 4.09 | 1.60
45 | 8.17 | 8.15 | ... | ...
50 | 9.08 | 10.0 | 5.11 | 2.44
75 | 13.6 | 22.4 | 7.66 | 5.32
100 | 18.2 | 39.0 | 10.2 | 9.46
125 | ... | ... | 12.8 | 14.9
150 | ... | ... | 15.3 | 21.2
175 | ... | ... | 17.1 | 28.1
200 | ... | ... | 20.4 | 37.5
----------+--------------+--------------+--------------+--------------
----------+-----------------------------+-----------------------------
Gallons | 2-1/2 Inch. | 3 Inch.
discharged|--------------+--------------+--------------+--------------
per |Veloc. in Pipe| Friction Loss|Veloc. in Pipe| Friction Loss
minute. | per second. | in pounds. | per second. | in pounds.
----------+--------------+--------------+--------------+--------------
25 | 1.63 | 0.21 | 1.13 | 0.10
50 | 3.26 | 0.81 | 2.27 | 0.35
75 | 4.90 | 1.80 | 3.40 | 0.74
100 | 6.53 | 3.20 | 4.54 | 1.31
125 | 8.16 | 4.89 | 5.67 | 1.99
150 | 9.80 | 7.00 | 6.81 | 2.85
175 | 11.4 | 9.46 | 7.94 | 3.85
200 | 13.1 | 12.47 | 9.08 | 5.02
250 | 16.3 | 19.66 | 11.3 | 7.76
300 | 19.6 | 28.06 | 13.6 | 11.2
350 | ... | ... | 15.9 | 15.2
400 | ... | ... | 18.2 | 19.5
450 | ... | ... | 20.4 | 25.0
500 | ... | ... | 22.7 | 30.8
----------+--------------+--------------+--------------+--------------
----------+-----------------------------+-----------------------------
Gallons | 4 Inch. | 6 Inch.
discharged|--------------+--------------+--------------+--------------
per |Veloc. in Pipe| Friction Loss|Veloc. in Pipe| Friction Loss
minute. | per second. | in pounds. | per second. | in pounds.
----------+--------------+--------------+--------------+--------------
50 | 1.28 | 0.09 | ... | ...
75 | ... | ... | ... | ...
100 | 2.55 | 0.33 | 1.13 | 0.05
150 | 3.83 | 0.69 | 1.70 | 0.10
200 | 5.11 | 1.22 | 2.27 | 0.17
250 | 6.39 | 1.89 | 2.84 | 0.26
300 | 7.66 | 2.66 | 3.40 | 0.37
350 | 8.94 | 3.65 | 3.97 | 0.50
400 | 10.2 | 4.73 | 4.54 | 0.65
450 | 11.5 | 6.01 | 5.11 | 0.81
500 | 12.8 | 7.43 | 5.67 | 0.96
----------+--------------+--------------+--------------+--------------
NOTE.—The quantity of a fluid discharged through a pipe or an orifice
is increased by heating the liquid: because heat diminishes the
cohesion of the particles, which exists to a certain degree, in all
liquids.
FRICTION LOSS IN POUNDS PRESSURE, FOR EACH 100 FEET OF LENGTH IN
DIFFERENT SIZE CLEAN IRON PIPES DISCHARGING GIVEN QUANTITIES OF WATER
PER MINUTE. ALSO VELOCITY OF FLOW IN PIPE, IN FEET PER SECOND.
_G. A. Ellis, C. E._
----------+----------------------------+----------------------------
Gallons | 6 Inch. | 8 Inch.
discharged|--------------+-------------+--------------+-------------
per |Veloc. in Pipe|Friction Loss|Veloc. in Pipe|Friction Loss
minute. | per second. | in pounds. | per second. | in pounds.
----------+--------------+-------------+--------------+-------------
250 | 2.84 | 0.26 | 1.59 | 0.07
500 | 5.67 | 0.98 | 3.19 | 0.25
750 | 8.51 | 2.21 | 4.79 | 0.53
1,000 | 11.3 | 3.88 | 6.38 | 0.94
1,250 | ... | ... | 7.97 | 1.46
1,500 | ... | ... | 9.57 | 2.09
----------+--------------+-------------+--------------+-------------
----------+----------------------------+----------------------------
Gallons | 10 Inch. | 12 Inch.
discharged|--------------+-------------+--------------+-------------
per |Veloc. in Pipe|Friction Loss|Veloc. in Pipe|Friction Loss
minute. | per second. | in pounds. | per second. | in pounds.
----------+--------------+-------------+--------------+-------------
250 | 1.02 | 0.03 | 0.71 | 0.01
500 | 2.04 | 0.09 | 1.42 | 0.04
750 | 3.06 | 0.18 | 2.13 | 0.08
1,000 | 4.08 | 0.32 | 2.84 | 0.13
1,250 | 5.10 | 0.49 | 3.55 | 0.20
1,500 | 6.12 | 0.70 | 4.26 | 0.29
1,750 | 7.15 | 0.95 | 4.96 | 0.38
2,000 | 8.17 | 1.23 | 5.67 | 0.49
2,250 | ... | ... | 6.38 | 0.63
2,500 | ... | ... | 7.09 | 0.77
3,000 | ... | ... | 8.51 | 1.11
----------+--------------+-------------+--------------+-------------
----------+----------------------------+----------------------------
Gallons | 14 Inch. | 16 Inch.
discharged|--------------+-------------+--------------+-------------
per |Veloc. in Pipe|Friction Loss|Veloc. in Pipe|Friction Loss
minute. | per second. | in pounds. | per second. | in pounds.
----------+--------------+-------------+--------------+-------------
500 | 1.04 | 0.017 | 0.80 | 0.009
1,000 | 2.08 | 0.062 | 1.60 | 0.036
1,500 | 3.13 | 0.135 | 2.39 | 0.071
2,000 | 4.17 | 0.234 | 3.19 | 0.123
2,500 | 5.21 | 0.362 | 3.99 | 0.188
3,000 | 6.25 | 0.515 | 4.79 | 0.267
3,500 | 7.29 | 0.697 | 5.59 | 0.365
4,000 | 8.34 | 0.910 | 6.38 | 0.472
4,500 | ... | ... | 7.18 | 0.593
5,000 | ... | ... | 7.98 | 0.730
----------+--------------+-------------+--------------+-------------
----------+----------------------------+----------------------------
Gallons | 18 Inch. | 20 Inch.
discharged|--------------+-------------+--------------+-------------
per |Veloc. in Pipe|Friction Loss|Veloc. in Pipe|Friction Loss
minute. | per second. | in pounds. | per second. | in pounds.
----------+--------------+-------------+--------------+-------------
500 | 0.63 | 0.005 | ... | ...
1,000 | 1.26 | 0.020 | 1.02 | 0.012
1,500 | 1.89 | 0.040 | ... | ...
2,000 | 2.52 | 0.071 | 2.04 | 0.042
2,500 | 3.15 | 0.107 | ... | ...
3,000 | 3.78 | 0.150 | 3.06 | 0.091
3,500 | 4.41 | 0.204 | ... | ...
4,000 | 5.04 | 0.263 | 4.08 | 0.158
4,500 | 5.67 | 0.333 | ... | ...
5,000 | 6.30 | 0.408 | 5.11 | 0.244
6,000 | 7.56 | 0.585 | 6.13 | 0.348
7,000 | ... | ... | 7.15 | 0.472
8,000 | ... | ... | 8.17 | 0.612
----------+--------------+-------------+--------------+-------------
----------+----------------------------+----------------------------
Gallons | 24 Inch. | 30 Inch.
discharged|--------------+-------------+--------------+-------------
per |Veloc. in Pipe|Friction Loss|Veloc. in Pipe|Friction Loss
minute. | per second. | in pounds. | per second. | in pounds.
----------+--------------+-------------+--------------+-------------
1,000 | 0.72 | 0.005 | 0.45 | 0.002
2,000 | 1.44 | 0.020 | 0.91 | 0.006
3,000 | 2.16 | 0.047 | 1.36 | 0.012
4,000 | 2.88 | 0.067 | 1.82 | 0.022
5,000 | 4.60 | 0.102 | 2.27 | 0.035
6,000 | 4.32 | 0.146 | 2.72 | 0.048
7,000 | 5.04 | 0.196 | 3.18 | 0.065
8,000 | 5.76 | 0.255 | 3.63 | 0.083
9,000 | 6.47 | 0.323 | 4.08 | 0.105
10,000 | 7.19 | 0.398 | 4.54 | 0.131
----------+--------------+-------------+--------------+-------------
NOTE.—The velocity with which a liquid issues from an infinitely
small orifice in the bottom or sides of a vessel that is kept full is
equal to that which a heavy body would acquire by falling from the
surface level to the level of the orifice.
TABLE SHOWING FRICTIONAL HEADS AT GIVEN RATES OF DISCHARGE IN CLEAN
CAST IRON PIPES FOR EACH 1000 FEET OF LENGTH, CONDENSED FROM ELABORATE
TABLES PREPARED BY MESSRS. GEO. A. ELLIS AND A. H. HOWLAND, CIVIL
ENGINEERS, BOSTON, MASS.
-----------+-------------+----------------------+----------------------
| | 4-INCH PIPE. | 6-INCH PIPE.
|U. S. gallons|--------+-------------+--------+-------------
U. S. | discharged | | Friction | | Friction
gallons | per |Velocity| Head. |Velocity| Head.
discharged | twenty-four | in +------+------+ in +------+------
per minute.| hours. | Feet. | Feet.|Pounds| Feet. | Feet.|Pounds
-----------+-------------+--------+------+------+--------+------+------
25 | 36000 | .64 | .59| .26| .28 | .11| .05
50 | 72000 | 1.28 | 2.01| .87| .57 | .32| .14
100 | 144000 | 2.55 | 7.36| 3.19| 1.13 | 1.08| .47
150 | 216000 | 3.83 | 16.05| 6.95| 1.70 | 2.28| .99
200 | 288000 | 5.11 | 28.09| 12.17| 2.27 | 3.92| 1.70
250 | 360000 | 6.37 | 43.47| 18.83| 2.84 | 6.00| 2.60
300 | 432000 | 7.66 | 62.20| 26.94| 3.40 | 8.52| 3.69
350 | 504000 | 8.94 | 84.26| 36.50| 3.97 | 11.48| 4.97
400 | 576000 | 10.21 |109.68| 47.50| 4.54 | 14.89| 6.45
450 | 648000 | 11.49 |138.43| 59.96| 5.11 | 18.73| 8.11
500 | 720000 | 12.77 |170.53| 73.87| 5.67 | 23.01| 9.97
600 | 864000 | 15.32 |244.76|106.02| 6.81 | 32.89| 14.25
700 | 1008000 | 17.87 |332.36|143.98| 7.94 | 44.54| 19.08
800 | 1152000 | ... | ... | ... | 9.08 | 57.95| 25.10
900 | 1290000 | ... | ... | ... | 10.21 | 73.12| 31.67
1000 | 1440000 | ... | ... | ... | 11.35 | 90.05| 38.99
1200 | 1728000 | ... | ... | ... | 13.61 |129.20| 55.96
1400 | 2016000 | ... | ... | ... | 15.88 |175.38| 75.97
1600 | 2304000 | ... | ... | ... | 18.15 |228.62| 99.0
1800 | 2592000 | ... | ... | ... | 20.42 |288.90|125.14
2000 | 2880000 | ... | ... | ... | 22.69 |356.22|154.30
-----------+-------------+--------+------+------+--------+------+------
-----------+-------------+----------------------+----------------------
| | 8-INCH PIPE. | 10-INCH PIPE.
|U. S. gallons|----------------------+----------------------
U. S. | discharged | | Friction | | Friction
gallons | per |Velocity| Head. |Velocity| Head.
discharged | twenty-four | in +-------------+ in +-------------
per minute.| hours. | Feet. | Feet.|Pounds| Feet. | Feet.|Pounds
-----------+-------------+--------+------+------+--------+------+------
25 | 36000 | .16 | .04| .02| .10 | .02| .01
50 | 72000 | .32 | .10| .04| .20 | .04| .02
100 | 144000 | .64 | .29| .13| .41 | .11| .05
150 | 216000 | .96 | .60| .26| .61 | .22| .10
200 | 288000 | 1.28 | 1.01| .44| .82 | .36| .16
250 | 360000 | 1.60 | 1.52| .66| 1.02 | .54| .23
300 | 432000 | 1.91 | 2.13| .92| 1.23 | .75| .32
350 | 504000 | 2.23 | 2.85| 1.24| 1.43 | .99| .43
400 | 576000 | 2.55 | 3.68| 1.59| 1.63 | 1.27| .55
450 | 648000 | 2.87 | 4.61| 2.00| 1.83 | 1.58| .69
500 | 720000 | 3.19 | 5.64| 2.44| 2.04 | 1.93| .84
600 | 864000 | 3.83 | 8.03| 3.48| 2.45 | 2.72| 1.18
700 | 1008000 | 4.47 | 10.83| 4.69| 2.86 | 3.66| 1.58
800 | 1152000 | 5.09 | 14.05| 6.08| 3.27 | 4.73| 2.05
900 | 1290000 | 5.74 | 17.68| 7.69| 3.68 | 5.93| 2.57
1000 | 1440000 | 6.38 | 21.74| 9.41| 4.08 | 7.28| 3.15
1200 | 1728000 | 7.66 | 31.10| 13.47| 4.90 | 10.38| 4.50
1400 | 2016000 | 8.94 | 42.13| 18.25| 5.72 | 14.02| 6.07
1600 | 2304000 | 10.21 | 54.84| 23.75| 6.53 | 18.22| 7.89
1800 | 2592000 | 11.47 | 69.22| 29.98| 7.35 | 22.96| 9.95
2000 | 2880000 | 12.77 | 85.27| 36.93| 8.17 | 28.25| 12.34
2500 | 3600000 | 15.96 |132.70| 57.49| 10.21 | 43.87| 19.00
3000 | 4320000 | ... | ... | ... | 12.25 | 62.92| 27.25
-----------+-------------+--------+------+------+--------+------+------
-----------+-------------+----------------------+-----------------------
| | 12-INCH PIPE. | 14-INCH PIPE.
|U. S. gallons|----------------------+-----------------------
U. S. | discharged | | Friction | | Friction
gallons | per |Velocity| Head. |Velocity| Head.
discharged | twenty-four | in +-------------+ in |--------------
per minute.| hours. | Feet. | Feet.|Pounds| Feet. | Feet.|Pounds
-----------+-------------+--------+------+------+--------+------+-------
25 | 36000 | .07 | .01| ... | ... | ... | ...
50 | 72000 | .14 | .02| .01| .10 | .01| ...
100 | 144000 | .28 | .05| .02| .21 | .03| .01
150 | 216000 | .43 | .10| .04| .31 | .05| .02
200 | 288000 | .57 | .16| .07| .42 | .08| .04
250 | 360000 | .71 | .24| .10| .52 | .12| .05
300 | 432000 | .85 | .32| .14| .63 | .16| .07
350 | 504000 | .99 | .43| .18| .73 | .21| .09
400 | 576000 | 1.13 | .54| .23| .83 | .27| .12
450 | 648000 | 1.28 | .67| .29| .94 | .33| .14
500 | 720000 | 1.42 | .81| .35| 1.04 | .40| .17
600 | 864000 | 1.70 | 1.14| .49| 1.25 | .55| .24
700 | 1008000 | 1.98 | 1.52| .66| 1.46 | .73| .32
800 | 1152000 | 2.27 | 1.96| .85| 1.67 | .94| .41
900 | 1290000 | 2.55 | 2.45| 1.06| 1.88 | 1.17| .51
1000 | 1440000 | 2.84 | 3.00| 1.30| 2.08 | 1.43| .62
1200 | 1728000 | 3.40 | 4.26| 1.85| 2.50 | 2.02| .88
1400 | 2016000 | 3.97 | 5.74| 2.49| 2.91 | 2.72| 1.18
1600 | 2304000 | 4.54 | 7.44| 3.22| 3.33 | 3.51| 1.52
1800 | 2592000 | 5.11 | 9.36| 4.06| 3.75 | 4.41| 1.91
2000 | 2880000 | 5.67 | 11.50| 5.00| 4.17 | 5.41| 2.34
2500 | 3600000 | 7.09 | 17.82| 7.72| 5.21 | 8.35| 3.62
3000 | 4320000 | 8.51 | 25.51| 11.05| 6.25 | 11.93| 5.17
3500 | 5040000 | 9.93 | 34.58| 14.98| 7.29 | 16.14| 6.99
4000 | 5760000 | ... | ... | ... | 8.34 | 21.00| 9.10
4500 | 6480000 | ... | ... | ... | 9.38 | 26.49| 11.47
-----------+-------------+--------+------+------+--------+------+---------
NOTE.—There seems to be no form of water pipe so perfect as to make
it fit for use in any and all cases and open to no improvement, but,
in the present state of knowledge, tarred cast iron seems to come the
nearest to this desideratum.
TABLE SHOWING FRICTIONAL HEADS AT GIVEN RATES OF DISCHARGE IN CLEAN
CAST IRON PIPES FOR EACH 1000 FEET OF LENGTH, CONDENSED FROM ELABORATE
TABLES PREPARED BY MESSRS. GEO. A. ELLIS AND A. H. HOWLAND, CIVIL
ENGINEERS, BOSTON, MASS.
------------+------------+-----------------------+-----------------------
U.S. gallons|U.S. gallons| 16-INCH PIPE. | 18-INCH PIPE.
discharged | discharged +-----------------------+--------+--------------
per minute.| per twenty-|Velocity| Friction |Velocity| Friction
| four hours.| in | Head. | in | Head.
| | feet. +------+-------+ feet. +------+-------
| | |Feet. |Pounds.| |Feet. |Pounds.
------------+------------+--------+------+-------+--------+------+-------
500 | 720000 | .80 | .22 | .09 | .63 | .13 | .06
1000 | 1440000 | 1.60 | .76 | .34 | 1.26 | .44 | .19
1500 | 2160000 | 2.39 | 1.63 | .71 | 1.89 | .93 | .40
2000 | 2880000 | 3.19 | 2.82 | 1.22 | 2.52 | 1.60 | .69
2500 | 3600000 | 3.99 | 4.34 | 1.88 | 3.15 | 2.45 | 1.06
3000 | 4320000 | 4.79 | 6.19 | 2.68 | 3.78 | 3.48 | 1.51
3500 | 5040000 | 5.59 | 8.37 | 3.63 | 4.41 | 4.70 | 2.03
4000 | 5760000 | 6.38 |10.87 | 4.71 | 5.04 | 6.09 | 2.64
4500 | 6480000 | 7.18 |13.70 | 5.93 | 5.67 | 7.67 | 3.32
5000 | 7200000 | 7.98 |16.85 | 7.30 | 6.30 | 9.43 | 4.08
5500 | 7920000 | 8.78 |20.33 | 8.71 | 6.93 |11.38 | 4.92
6000 | 8640000 | ... | ... | ... | 7.57 |13.49 | 5.84
------------+------------+--------+------+-------+--------+------+-------
------------+------------+-----------------------+-----------------------
U.S. gallons|U.S. gallons| 20-INCH PIPE. | 24-INCH PIPE.
discharged | discharged +--------+--------------+--------+--------------
per minute.| per twenty-|Velocity| Friction |Velocity| Friction
| four hours.| in | Head. | in | Head.
| | feet. +------+-------+ feet. +------+-------
| | |Feet. |Pounds.| |Feet. |Pounds.
------------+------------+--------+------+-------+--------+------+-------
500 | 720000 | .51 | .08 | .04 | .35 | .04 | .02
1000 | 1440000 | 1.02 | .27 | .12 | .71 | .12 | .05
1500 | 2160000 | 1.53 | .56 | .24 | 1.06 | .24 | .10
2000 | 2880000 | 2.04 | .96 | .42 | 1.42 | .41 | .18
2500 | 3600000 | 2.55 | 1.47 | .64 | 1.77 | .62 | .27
3000 | 4320000 | 3.06 | 2.09 | .90 | 2.13 | .87 | .38
3500 | 5040000 | 3.57 | 2.81 | 1.22 | 2.48 | 1.16 | .50
4000 | 5760000 | 4.08 | 3.64 | 1.58 | 2.84 | 1.50 | .65
4500 | 6480000 | 4.59 | 4.58 | 1.98 | 3.19 | 1.88 | .82
5000 | 7200000 | 5.11 | 5.62 | 2.43 | 3.55 | 2.31 | 1.00
5500 | 7920000 | 5.62 | 6.77 | 2.93 | 3.90 | 2.77 | 1.20
6000 | 8640000 | 6.13 | 8.03 | 3.48 | 4.26 | 3.28 | 1.42
7000 | 10080000 | 7.15 |10.86 | 4.71 | 4.96 | 4.43 | 1.92
8000 | 11520000 | ... | ... | ... | 5.67 | 5.75 | 2.49
9000 | 12960000 | ... | ... | ... | 6.38 | 7.25 | 3.14
------------+------------+--------+------+-------+-------+--------+------
------------+------------+-----------------------+----------------------
U.S. gallons|U.S. gallons| 30-INCH PIPE. | 36-INCH PIPE.
discharged | discharged +--------+--------------+--------+-------------
per minute.| per twenty-|Velocity| Friction |Velocity| Friction
| four hours.| in | Head. | in | Head.
| | feet. +------+-------+ feet. +-----+-------
| | |Feet. |Pounds.| |Feet.|Pounds.
------------+------------+--------+------+-------+--------+-----+-------
500 | 720000 | .23 | .01 | .00 | .16 | .01 | .00
1000 | 1440000 | .45 | .04 | .02 | .32 | .02 | .01
1500 | 2160000 | .68 | .09 | .04 | .47 | .04 | .02
2000 | 2880000 | .91 | .15 | .06 | .63 | .06 | .03
2500 | 3600000 | 1.13 | .22 | .09 | .79 | .09 | .04
3000 | 4320000 | 1.36 | .30 | .13 | .95 | .13 | .06
3500 | 5040000 | 1.59 | .40 | .17 | 1.10 | .17 | .07
4000 | 5760000 | 1.82 | .52 | .22 | 1.26 | .22 | .09
4500 | 6480000 | 2.04 | .64 | .28 | 1.42 | .27 | .12
5000 | 7200000 | 2.27 | .78 | .34 | 1.58 | .33 | .14
5500 | 7920000 | 2.50 | .94 | .41 | 1.73 | .39 | .17
6000 | 8640000 | 2.72 | 1.11 | .48 | 1.89 | .46 | .20
7000 | 10080000 | 3.18 | 1.49 | .65 | 2.21 | .62 | .27
8000 | 11520000 | 3.63 | 1.93 | .84 | 2.52 | .80 | .35
9000 | 12960000 | 4.08 | 2.43 | 1.05 | 2.84 |1.00 | .43
10000 | 14400000 | 4.54 | 2.98 | 1.29 | 3.15 |1.23 | .53
11000 | 15840000 | 5.00 | 3.59 | 1.55 | 3.46 |1.47 | .64
12000 | 17280000 | 5.44 | 4.25 | 1.84 | 3.78 |1.74 | .75
13000 | 18720000 | 5.90 | 4.97 | 2.15 | 4.09 |2.03 | .88
14000 | 20160000 | 6.36 | 5.75 | 2.49 | 4.41 |2.35 |1.02
15000 | 21600000 | 6.80 | 6.58 | 2.85 | 4.73 |2.69 |1.17
16000 | 23040000 | ... | ... | ... | 5.05 |3.46 |1.32
17000 | 24480000 | ... | ... | ... | 5.36 |3.43 |1.49
18000 | 25920000 | ... | ... | ... | 5.68 |3.83 |1.66
20000 | 28800000 | ... | ... | ... | 6.30 |4.71 |2.04
------------+------------+--------+------+-------+--------+-----+-------
NOTE.—A pressure of one lb. per sq. in. is exerted by a column of
water 2.3093 feet or 27.71 inches high at 62° F.; and a pressure of
one atmosphere, or 14.7 lbs. per sq. in. is exerted by a column of
water 33.947 feet high, or 10.347 meters at 62° F.
TABLE.
The pressure of water in pounds per square inch for every ft. in height
to 300 feet and then by intervals to 1,000 feet head. By this table,
from the pounds pressure per square inch, the feet head is readily
obtained and _vice versa_.
=======+===========
Feet | Pressure
Head. |per sq. in.
-------+-----------
1 | 0.43
2 | 0.86
3 | 1.30
4 | 1.73
5 | 2.16
6 | 2.59
7 | 3.03
8 | 3.46
9 | 3.89
10 | 4.33
11 | 4.76
12 | 5.20
13 | 5.63
14 | 6.06
15 | 6.49
16 | 6.93
17 | 7.36
18 | 7.79
19 | 8.22
20 | 8.66
21 | 9.09
22 | 9.53
23 | 9.96
24 | 10.39
25 | 10.82
26 | 11.26
27 | 11.69
28 | 12.12
29 | 12.55
30 | 12.99
31 | 13.42
32 | 13.86
33 | 14.29
34 | 14.72
35 | 15.16
36 | 15.59
37 | 16.02
38 | 16.45
39 | 16.89
40 | 17.32
41 | 17.75
42 | 18.19
43 | 18.62
44 | 19.05
45 | 19.49
46 | 19.92
47 | 20.35
48 | 20.79
49 | 21.22
=50= | 21.65
51 | 22.09
52 | 22.52
53 | 22.95
54 | 23.39
55 | 23.82
56 | 24.26
57 | 24.69
58 | 25.12
59 | 25.55
60 | 25.99
61 | 26.42
62 | 26.85
63 | 27.29
64 | 27.72
65 | 28.15
66 | 28.58
67 | 29.02
68 | 29.45
69 | 29.88
70 | 30.32
71 | 30.75
72 | 31.18
73 | 31.62
74 | 32.05
75 | 32.48
76 | 32.92
77 | 33.35
78 | 33.78
79 | 34.21
80 | 34.65
81 | 35.08
82 | 35.52
83 | 35.95
84 | 36.39
85 | 36.82
86 | 37.25
87 | 37.68
88 | 38.12
89 | 38.53
90 | 38.98
91 | 39.42
92 | 39.85
93 | 40.28
94 | 40.72
95 | 41.15
96 | 41.58
97 | 42.01
98 | 42.45
99 | 42.88
=100= | 43.31
101 | 43.75
102 | 44.18
103 | 44.61
104 | 45.05
105 | 45.48
106 | 45.91
107 | 46.34
108 | 46.78
109 | 47.21
110 | 47.64
111 | 48.08
112 | 48.51
113 | 48.94
114 | 49.38
115 | 49.81
116 | 50.24
117 | 50.68
118 | 51.11
119 | 51.54
120 | 51.98
121 | 52.41
122 | 52.84
123 | 53.28
124 | 53.71
125 | 54.15
126 | 54.58
127 | 55.01
128 | 55.44
129 | 55.88
130 | 56.31
131 | 56.74
132 | 57.18
133 | 57.61
134 | 58.04
135 | 58.48
136 | 58.91
137 | 59.34
138 | 59.77
139 | 60.21
140 | 60.64
141 | 61.07
142 | 61.51
143 | 61.94
144 | 62.37
145 | 62.81
146 | 63.24
147 | 63.67
148 | 64.10
149 | 64.54
=150= | 64.97
151 | 65.40
152 | 65.84
153 | 66.27
154 | 66.70
155 | 67.14
156 | 67.57
157 | 68.00
158 | 68.43
159 | 68.87
160 | 69.31
161 | 69.74
162 | 70.17
163 | 70.61
164 | 71.04
165 | 71.47
166 | 71.91
167 | 72.34
168 | 72.77
169 | 73.29
170 | 73.64
171 | 74.07
172 | 74.50
173 | 74.94
174 | 75.37
175 | 75.80
176 | 76.23
177 | 76.67
178 | 77.10
179 | 77.53
180 | 77.97
181 | 78.40
182 | 78.84
183 | 79.27
184 | 79.70
185 | 80.14
186 | 80.57
187 | 81.00
188 | 81.43
189 | 81.87
190 | 82.30
191 | 82.73
192 | 83.17
193 | 83.60
194 | 84.03
195 | 84.47
196 | 84.90
197 | 85.33
198 | 85.76
199 | 86.20
=200= | 86.63
201 | 87.07
202 | 87.50
203 | 87.93
204 | 88.36
205 | 88.80
206 | 89.21
207 | 89.66
208 | 90.10
209 | 90.53
210 | 90.96
211 | 91.39
212 | 91.83
213 | 92.26
214 | 92.69
215 | 93.13
216 | 93.56
217 | 93.99
218 | 94.43
219 | 94.86
220 | 95.30
221 | 95.73
222 | 96.16
223 | 96.60
224 | 97.03
225 | 97.46
226 | 97.90
227 | 98.33
228 | 98.76
229 | 99.20
230 | 99.63
231 | 100.00
232 | 100.49
233 | 100.93
234 | 101.36
235 | 101.79
236 | 102.23
237 | 102.66
238 | 103.09
239 | 103.53
240 | 103.96
241 | 104.39
242 | 104.83
243 | 105.26
244 | 105.69
245 | 106.13
246 | 106.56
247 | 106.99
248 | 107.43
249 | 107.86
=250= | 108.29
251 | 108.73
252 | 109.15
253 | 109.59
254 | 110.03
255 | 110.46
256 | 110.89
257 | 111.32
258 | 111.76
259 | 112.19
260 | 112.62
261 | 113.03
262 | 113.49
263 | 113.92
264 | 114.36
265 | 114.79
266 | 115.22
267 | 115.66
268 | 116.09
269 | 116.52
270 | 116.96
271 | 117.39
272 | 117.82
273 | 118.26
274 | 118.69
275 | 119.12
276 | 119.56
277 | 119.99
278 | 120.42
279 | 120.85
280 | 121.29
281 | 121.73
282 | 122.15
283 | 122.59
284 | 123.02
285 | 123.45
286 | 123.89
287 | 124.32
288 | 124.75
289 | 125.18
290 | 125.62
291 | 126.05
292 | 126.48
293 | 126.92
294 | 127.35
295 | 127.78
296 | 128.22
297 | 128.65
298 | 129.08
299 | 129.51
=300= | 129.95
310 | 134.28
320 | 138.62
330 | 142.95
340 | 147.28
=350= | 151.61
360 | 155.94
370 | 160.27
380 | 164.61
390 | 168.94
=400= | 173.27
500 | 216.58
600 | 259.90
700 | 303.22
800 | 346.54
900 | 389.86
1000 | 433.18
-------+--------
TABLE OF FRICTION HEADS IN FEET IN SMALL PIPES 100 FEET LONG UNDER
GIVEN DISCHARGE.
-----------+----------++-----------------------------
| Gallons || 1/2-IN. DIAM.
Gallons |discharged|+---------------+-------------
discharged | per 24 ||Velocity in ft.|Friction head
per minute.| hours. || per second. | in feet.
-----------+----------++---------------+-------------
2.5 | 3,600 || 4.08 | 18.20
5 | 7,200 || 8.17 | 66.82
7.5 | 10,800 || 12.25 | 142.9
10 | 14,400 || 16.33 | 243.3
-----------+----------++---------------+-------------
-----------+----------++-----------------------------
| Gallons || 3/4-IN. DIAM.
Gallons |discharged|+---------------+-------------
discharged | per 24 ||Velocity in ft.|Friction head
per minute.| hours. || per second. | in feet.
-----------+----------++---------------+-------------
2.5 | 3,600 || 1.81 | 2.78
5 | 7,200 || 3.63 | 9.40
7.5 | 10,800 || 5.44 | 20.17
10 | 14,400 || 7.25 | 34.77
12.5 | 18,000 || 9.06 | 52.11
15 | 21,600 || 10.87 | 73.61
17.5 | 25,200 || 12.69 | 98.80
20 | 28,800 || 14.50 | 127.6
22.5 | 32,400 || 16.31 | 160.7
25 | 36,000 || 18.12 | 197.7
-----------+----------++---------------+-------------
-----------+----------++-----------------------------
| Gallons || 1-IN. DIAM.
Gallons |discharged|+---------------+-------------
discharged | per 24 ||Velocity in ft.|Friction head
per minute.| hours. || per second. | in feet.
-----------+----------++---------------+-------------
2.5 | 3,600 || 1.02 | .74
5 | 7,200 || 2.04 | 2.52
7.5 | 10,800 || 3.06 | 5.14
10 | 14,400 || 4.08 | 8.75
12.5 | 18,000 || 5.10 | 13.22
15 | 21,600 || 6.13 | 18.84
17.5 | 25,200 || 7.15 | 25.14
20 | 28,800 || 8.17 | 32.27
22.5 | 32,400 || 9.18 | 40.17
25 | 36,000 || 10.20 | 48.90
30 | 43,200 || 12.23 | 68.70
35 | 50,400 || 14.25 | 92.10
40 | 57,600 || 16.29 | 116.8
45 | 64,800 || 18.34 | 150.6
50 | 72,000 || 20.37 | 186.7
-----------+----------++---------------+-------------
-----------+----------++-----------------------------
| Gallons || 1-1/4-IN. DIAM.
Gallons |discharged|+---------------+-------------
discharged | per 24 ||Velocity in ft.|Friction head
per minute.| hours. || per second. | in feet.
-----------+----------++---------------+-------------
5 | 7,200 || 1.31 | .83
10 | 14,400 || 2.62 | 2.85
15 | 21,600 || 3.92 | 5.90
20 | 28,800 || 5.22 | 10.21
25 | 36,000 || 6.53 | 15.50
30 | 43,200 || 7.84 | 22.34
35 | 50,400 || 9.14 | 28.99
40 | 57,600 || 10.45 | 37.29
45 | 64,800 || 11.76 | 46.47
50 | 72,000 || 13.07 | 57.16
55 | 79,200 || 14.38 | 68.62
60 | 86,400 || 15.69 | 81.35
65 | 93,600 || 17.00 | 95.11
70 | 100,800 || 18.31 | 109.9
75 | 108,000 || 19.62 | 126.1
-----------+----------++---------------+-------------
-----------+----------++-----------------------------
| Gallons || 1-1/2-IN. DIAM.
Gallons |discharged|+---------------+-------------
discharged | per 24 ||Velocity in ft.|Friction head
per minute.| hours. || per second. | in feet.
-----------+----------++---------------+-------------
5 | 7,200 || .91 | .51
10 | 14,400 || 1.82 | 1.33
15 | 21,600 || 2.73 | 2.80
20 | 28,800 || 3.63 | 4.59
25 | 36,000 || 4.54 | 6.99
30 | 43,200 || 5.45 | 9.86
35 | 50,400 || 6.36 | 13.14
40 | 57,600 || 7.26 | 16.94
45 | 64,800 || 8.17 | 21.09
50 | 72,000 || 9.08 | 25.66
60 | 86,400 || 10.90 | 36.15
70 | 100,800 || 12.72 | 48.84
80 | 115,200 || 14.54 | 63.53
90 | 129,600 || 16.36 | 79.78
100 | 144,000 || 18.17 | 98.23
-----------+----------++---------------+-------------
-----------+----------++-----------------------------
| Gallons || 2-IN. DIAM.
Gallons |discharged|+---------------+-------------
discharged | per 24 ||Velocity in ft.|Friction head
per minute.| hours. || per second. | in feet.
-----------+------- --++---------------+-------------
5 | 7,200 || 1 | ...
10 | 14,400 || 1.02 | .31
20 | 28,800 || 2.04 | 1.17
30 | 43,200 || 3.06 | 2.36
40 | 57,600 || 4.09 | 4.17
50 | 72,000 || 5.11 | 6.34
60 | 86,400 || 6.13 | 8.92
70 | 100,800 || 7.15 | 11.83
80 | 115,200 || 8.18 | 15.27
90 | 129,600 || 9.20 | 19.11
100 | 144,000 || 10.22 | 23.23
125 | 180,000 || 12.80 | 35.78
150 | 216,000 || 15.3 | 50.60
175 | 252,000 || 17.9 | 69.13
200 | 288,000 || 20.4 | 89.51
-----------+----------++---------------+-------------
-----------+----------++-----------------------------
| Gallons || 2-1/2-IN. DIAM..
Gallons |discharged|+---------------+-------------
discharged | per 24 ||Velocity in ft.|Friction head
per minute.| hours. || per second. | in feet.
-----------+------- --++---------------+-------------
25 | 36,000 || 1.63 | .58
50 | 72,000 || 3.26 | 2.10
75 | 108,000 || 4.90 | 4.58
100 | 144,000 || 6.53 | 7.95
125 | 180,000 || 8.16 | 12.10
150 | 216,000 || 9.80 | 17.05
175 | 252,000 || 11.43 | 22.88
200 | 288,000 || 13.07 | 29.67
225 | 324,000 || 14.70 | 37.14
250 | 360,000 || 16.34 | 45.81
275 | 396,000 || 17.97 | 55.32
300 | 432,000 || 19.60 | 65.68
350 | 468,000 || 21.24 | 77.01
400 | 576,000 || 22.87 | 89.11
-----------+----------++---------------+-------------
-----------+----------++-----------------------------
| Gallons || 3-IN. DIAM.
Gallons |discharged|+---------------+-------------
discharged | per 24 ||Velocity in ft.|Friction head
per minute.| hours. || per second. | in feet.
-----------+------- --++---------------+-------------
50 | 72,000 || 2.27 | .88
75 | 108,000 || 3.40 | 1.90
100 | 144,000 || 4.54 | 3.29
125 | 180,000 || 5.67 | 5.00
150 | 216,000 || 6.81 | 7.05
175 | 252,000 || 7.94 | 9.41
200 | 288,000 || 9.08 | 12.13
225 | 324,000 || 10.22 | 15.17
250 | 360,000 || 11.36 | 18.69
275 | 396,000 || 12.50 | 22.52
300 | 432,000 || 13.64 | 26.26
350 | 468,000 || 15.91 | 35.80
400 | 576,000 || 18.18 | 46.64
450 | 648,000 || 20.45 | 88.70
500 | 720,000 || 22.72 | 73.82
-----------+----------++---------------+-------------
Contents of cylinders, in cubic feet and in U. S. gallons, for one foot
of length.
-----------+-------------+-----------------------
| | FOR 1 FOOT
| | IN LENGTH.
| +------------+----------
Diameter in| Diameter in | Cubic Feet.|Gallons of
Inches. |Decimals of a|Also area in| 231 Cubic
| Foot. |square feet.| Inches.
-----------+-------------+------------+----------
1/4 | .0208 | .0003 | .0026
5/16 | .0260 | .0005 | .0040
3/8 | .0313 | .0008 | .0057
7/16 | .0365 | .0010 | .0078
1/2 | .0417 | .0014 | .0102
9/16 | .0469 | .0017 | .0129
5/8 | .0521 | .0021 | .0159
11/16 | .0573 | .0026 | .0193
3/4 | .0625 | .0031 | .0230
13/16 | .0677 | .0036 | .0270
7/8 | .0729 | .0042 | .0312
15/16 | .0781 | .0048 | .0359
1. | .0833 | .0055 | .0408
1/4 | .1042 | .0085 | .0638
1/2 | .1250 | .0123 | .0918
3/4 | .1458 | .0168 | .1250
2. | .1667 | .0218 | .1632
1/4 | .1875 | .0276 | .2066
1/2 | .2083 | .0341 | .2550
3/4 | .2292 | .0413 | .3085
3. | .2500 | .0491 | .3673
1/4 | .2708 | .0576 | .4310
1/2 | .2917 | .0668 | .4998
3/4 | .3125 | .0767 | .5738
4. | .3333 | .0878 | .6528
1/4 | .3542 | .0985 | .7370
1/2 | .3750 | .1105 | .8263
3/4 | .3958 | .1231 | .9205
5. | .4167 | .1364 | 1.020
1/4 | .4375 | .1503 | 1.124
1/2 | .4583 | .1650 | 1.234
3/4 | .4792 | .1803 | 1.349
6. | .5000 | .1963 | 1.469
1/4 | .5208 | .2180 | 1.594
1/2 | .5417 | .2305 | 1.724
3/4 | .5625 | .2485 | 1.859
7. | .5833 | .2673 | 1.999
1/4 | .6042 | .2868 | 2.144
1/2 | .6250 | .3068 | 2.295
3/4 | .6458 | .3275 | 2.450
8. | .6667 | .3490 | 2.611
1/4 | .6875 | .3713 | 2.777
1/2 | .7083 | .3940 | 2.948
3/4 | .7292 | .4175 | 3.125
9. | .7500 | .4418 | 3.305
1/4 | .7708 | .4668 | 3.492
1/2 | .7917 | .4923 | 3.682
3/4 | .8125 | .5185 | 3.879
10. | .8333 | .5455 | 4.081
1/4 | .8542 | .5730 | 4.286
1/2 | .8750 | .6013 | 4.498
3/4 | .8958 | .6303 | 4.714
11. | .9167 | .6600 | 4.937
1/4 | .9375 | .6903 | 5.163
1/2 | .9583 | .7213 | 5.395
3/4 | .9792 | .7530 | 5.633
12. | 1 Foot. | .7854 | 5.876
1/2 | 1.042 | .8523 | 6.375
13. | 1.083 | .9218 | 6.895
1/2 | 1.125 | .9940 | 7.435
14. | 1.167 | 1.069 | 7.997
1/2 | 1.208 | 1.147 | 8.578
15. | 1.250 | 1.227 | 9.180
1/2 | 1.292 | 1.310 | 9.801
16. | 1.333 | 1.396 | 10.44
1/2 | 1.375 | 1.485 | 11.11
17. | 1.417 | 1.576 | 11.79
1/2 | 1.458 | 1.670 | 12.50
18. | 1.500 | 1.767 | 13.22
1/2 | 1.542 | 1.867 | 13.97
19. | 1.583 | 1.969 | 14.73
1/2 | 1.625 | 2.074 | 15.52
20. | 1.666 | 2.182 | 16.32
1/2 | 1.708 | 2.292 | 17.15
21. | 1.750 | 2.405 | 17.99
1/2 | 1.792 | 2.521 | 18.86
22. | 1.833 | 2.640 | 19.75
1/2 | 1.875 | 2.761 | 20.65
23. | 1.917 | 2.885 | 21.58
1/2 | 1.958 | 3.012 | 22.53
24. | 2.000 | 3.142 | 23.50
25. | 2.083 | 3.409 | 25.50
26. | 2.166 | 3.687 | 27.58
27. | 2.250 | 3.976 | 29.74
28. | 2.333 | 4.276 | 31.99
29. | 2.416 | 4.587 | 34.31
30. | 2.500 | 4.909 | 36.72
31. | 2.583 | 5.241 | 39.21
32. | 2.666 | 5.585 | 41.78
33. | 2.750 | 5.940 | 44.43
34. | 2.833 | 6.305 | 47.17
35. | 2.916 | 6.681 | 49.98
36. | 3.000 | 7.069 | 52.88
37. | 3.083 | 7.468 | 55.86
38. | 3.166 | 7.876 | 58.92
39. | 3.250 | 8.296 | 62.06
40. | 3.333 | 8.728 | 65.29
41. | 3.416 | 9.168 | 68.58
42. | 3.500 | 9.620 | 71.96
43. | 3.583 | 10.084 | 75.43
44. | 3.666 | 10.560 | 79.00
45. | 3.750 | 11.044 | 82.62
46. | 3.833 | 11.540 | 86.32
47. | 3.916 | 12.048 | 90.12
48. | 4.000 | 12.566 | 94.02
-----------+-------------+------------+----------
231 cubic inches equal one gallon, and 7.4805 gallons equal one cubic
foot.
For the contents of a greater diameter than any in the table, take
the quantity opposite one-_half_ said diameter and multiply it by 4.
Thus, the number of cubic feet in one foot length of a pipe 80 inches
in diameter, is equal to 8.728 × 4 = 34.912 cubic feet. So also with
gallons and areas.
SCHEDULE OF STANDARD FLANGES.
Adopted July 18, 1894, by a Committee of the Master Steam and Hot
Water Fitters’ Association, a Committee of the Society of Mechanical
Engineers of the United States, and the leading valve and fitting
manufacturers of the United States.
=======+===================+=========+===========+========
|Pipe thickness, | | |
|(_P_ + 100) | | |
|--------- | | |
Pipe | .4_S_ |Thickness| Stress on | Radius
size, | | nearest | pipe per | of
Inches.|_d_+.333(1-_d_/100)|fraction,| square | fillet,
| | inches. |inch at 200|inches.
| _S_-18,000 lbs. | | lbs. |
-------+-------------------+---------+-----------+--------
2 | .409 | 7/16 | 460 | 1/8
2-1/2| .429 | 7/16 | 550 | 1/8
3 | .448 | 7/16 | 690 | 1/8
3-1/2| .466 | 1/2 | 700 | 1/8
4 | .486 | 1/2 | 800 | 1/8
4-1/2| .498 | 1/2 | 900 | 1/8
5 | .525 | 1/2 | 1,000 | 1/8
6 | .563 | 9/16 | 1,060 | 1/8
7 | .60 | 5/8 | 1,120 | 1/8
8 | .639 | 5/8 | 1,280 | 1/8
9 | .678 | 11/16 | 1,310 | 3/16
10 | .713 | 3/4 | 1,330 | 3/16
12 | .79 | 13/16 | 1,470 | 3/16
14 | .864 | 7/8 | 1,600 | 3/16
15 | .904 | 15/16 | 1,600 | 3/16
16 | .946 |1 | 1,600 | 3/16
18 | 1.02 |1-1/16 | 1,690 | 3/16
20 | 1.09 |1-1/8 | 1,780 | 3/16
22 | 1.18 |1-3/16 | 1,850 | 1/4
24 | 1.25 |1-1/4 | 1,920 | 1/4
26 | 1.30 |1-5/16 | 1,980 | 1/4
28 | 1.38 |1-3/8 | 2,040 | 1/4
30 | 1.48 |1-1/2 | 2,000 | 1/4
36 | 1.71 |1-3/4 | 1,920 | 1/4
42 | 1.87 |2 | 2,100 | 1/4
48 | 2.17 |2-1/4 | 2,130 | 1/4
-------+-------------------+---------+-----------+--------
=======+==============+=========+===============+============
| | Flange | |
Pipe | |thickness| Flange | Width
size, | Flange | at hub | thickness | flange
Inches.| diameter, | for iron| at edge, | face,
| inches. | pipe, | inches. | inches.
| | inches. | |
-------+--------------+---------+---------------+------------
2 | 6 | 1 | 5/8 | 2
2-1/2| 7 | 1-1/8 | 11/16| 2-1/4
3 | 7-1/2| 1-1/4 | 3/4 | 2-1/4
3-1/2| 8-1/2| 1-1/4 | 13/16| 2-1/2
4 | 9 | 1-3/8 | 15/16| 2-1/2
4-1/2| 9-1/4| 1-3/8 | 15/16| 2-3/8
5 | 10 | 1-1/2 | 15/16| 2-1/2
6 | 11 | 1-1/2 | 1 | 2-1/2
7 | 12-1/2| 1-1/2 | 1-1/16 | 2-3/4
8 | 13-1/2| 1-3/4 | 1-1/8 | 2-3/4
9 | 15 | 1-3/4 | 1-1/8 | 3
10 | 16 | 2 | 1-3/16 | 3
12 | 19 | 2 | 1-1/4 | 3-1/2
14 | 21 | 2 | 1-3/8 | 3-1/2
15 | 22-1/4| 2 | 1-5/8 | 3-5/8
16 | 23-1/2| 2-1/4 | 1-7/16 | 3-3/4
18 | 25 | ... | 1-9/16 | 3-1/2
20 | 27-1/2| ... | 1-11/16| 3-3/4
22 | 29-1/2| ... | 1-13/16| 3-3/4
24 |31-1/2 32 | ... |1-1/4 1-7/8 |3-3/4 4
26 |33-3/4 34-1/4| ... |1-3/8 2 |3-7/8 4-1/8
28 |36 36-1/2| ... |1-7/16 2-1/16 |4 4-1/4
30 |38 38-3/4| ... |1-1/2 2-1/8 |4 4-3/8
36 |44-1/2 45-3/4| ... |1-3/4 2-3/8 |4-1/4 4-7/8
42 |51 52-3/4| ... |1-7/8 2-5/8 |4-1/2 5-3/8
48 |57-1/2 59-1/2| ... |2 2-3/4 |4-3/4 5-3/4
-------+--------------+---------+---------------+------------
=======+============+==============+======+============+=======+==========
| | | | | |
| | | | | | Stress on
| | | | | |each bolt,
Pipe | Width | | | | |per square
size, | flange | Bolt circle |Number| Bolt size | Bolt | inch at
Inches.| face, | diameter, | of | diameters, |length,| bottom of
| inches. | inches. |bolts.| inches. |inches.| thread at
| | | | | | 200 lbs.
-------+------------+--------------+------+------------+-------+----------
2 | 2 | 4-3/4| 4 | 1/2 5/8| 2 | 825
2-1/2| 2-1/4| 5-1/2| 4 | 1/2 5/8| 2-1/4 | 1,050
3 | 2-1/4| 6 | 4 | 1/2 5/8| 2-1/2 | 1,330
3-1/2| 2-1/2| 7 | 4 | 1/2 5/8| 2-1/2 | 2,530
4 | 2-1/2| 7-1/2| 4 | 3/8 3/4| 2-3/4 | 2,100
4-1/2| 2-3/8| 7-3/4| 8 | 5/8 3/4| 3 | 1,430
5 | 2-1/2| 8-1/2| 8 | 5/8 3/4| 3 | 1,630
6 | 2-1/2| 9-1/2| 8 | 5/8 3/4| 3 | 2,360
7 | 2-3/4| 10-3/4| 8 | 5/8 3/4| 3-1/4 | 3,200
8 | 2-3/4| 11-3/4| 8 | 5/8 3/4| 3-1/2 | 4,190
9 | 3 | 13-1/4| 12 | 5/8 3/4| 3-1/2 | 3,610
10 | 3 | 14-1/4| 12 | 5/8 7/8| 3-5/8 | 2,970
12 | 3-1/2| 17 | 12 | 3/4 7/8| 3-3/4 | 4,280
14 | 3-1/2| 18-3/4| 12 | 7/8 1 | 4-1/4 | 4,280
15 | 3-5/8| 20 | 16 | 7/8 1 | 4-1/4 | 3,660
16 | 3-3/4| 21-1/4| 16 | 7/8 1 | 4-1/4 | 4,210
18 | 3-1/2| 22-3/4| 16 |1 1-7/8| 4-3/4 | 4,540
20 | 3-3/4| 25 | 20 |1 1-1/8| 5 | 4,490
22 | 3-3/4| 27-1/4| 20 |1 1-1/4| 5-1/2 | 4,320
24 |3-3/4 4 |29-1/4 29-1/2| 20 |1 1-1/4| 5-1/2 | 5,130
26 |3-7/8 4-1/8|31-1/4 31-3/4| 24 |1 1-1/4| 5-3/4 | 5,030
28 |4 4-1/4|33-1/2 34 | 28 |1 1-1/4| 6 | 5,000
30 |4 4-3/8|35-1/2 36 | 28 |1-1/8 1-3/8| 6-1/4 | 4,590
36 |4-1/4 4-7/8|42 42-3/4| 32 |1-1/8 1-3/8| 6-1/2 | 5,790
42 |4-1/2 5-3/8|48-1/2 49-1/2| 36 |1-1/4 1-1/2| 7-1/4 | 5,700
48 |4-3/4 5-3/4|54-3/4 56 | 44 |1-3/8 1-1/2| 7-3/4 | 6,090
-------+------------+--------------+------+------------+-------+----------
DIMENSIONS OF CAST IRON PIPE, FLANGES, ETC.
(J. E. Codman, Engineers’ Club of Philadelphia, 1889.)
--------+----------+--------+--------+---------
Diameter|Diameter |Diameter|Diameter|Number
of Pipe.|of Flange.|of Bolt |of Bolt.|of Bolts.
| |Circle. | |
| | | |
--------+----------+--------+--------+---------
2 | 6-1/4 | 4-3/4 | 3/4 | 4
3 | 7-1/2 | 5-7/8 | 3/4 | 4
4 | 9 | 7 | 3/4 | 6
5 | 9-3/4 | 8 | 3/4 | 6
6 | 10-3/4 | 9-1/8 | 3/4 | 8
8 | 13-1/4 | 11-3/8 | 3/4 | 8
10 | 15-1/4 | 13-1/4 | 3/4 | 10
12 | 17-3/4 | 15-3/4 | 7/8 | 12
14 | 20 | 18 | 7/8 | 14
16 | 22 | 20 | 7/8 | 16
18 | 24 | 22-1/4 | 7/8 | 16
20 | 27 | 24-1/2 | 1 | 18
22 | 28-3/4 | 26-1/2 | 1 | 20
24 | 31-1/4 | 28-3/4 | 1 | 22
26 | 33-1/4 | 31 | 1 | 24
28 | 35-1/2 | 33-1/4 | 1 | 24
30 | 38 | 35-1/2 | 1 | 26
32 | 40 | 37-1/2 | 1-1/8 | 28
34 | 42-1/4 | 40 | 1-1/8 | 30
36 | 45 | 42 | 1-1/8 | 32
38 | 47 | 44 | 1-1/8 | 32
40 | 49 | 46 | 1-1/8 | 34
42 | 51-1/4 | 48-1/4 | 1-1/8 | 34
44 | 53-1/2 | 50-1/4 | 1-1/4 | 36
46 | 55-3/4 | 52-3/4 | 1-1/4 | 38
48 | 58 | 55 | 1-1/4 | 40
--------+----------+--------+--------+---------
--------+----------+-------------+--------+----------
Diameter|Thickness | Thickness |Weight |Weight of
of Pipe.|of Flange.| of Pipe. |per foot|Flange
| +-------+-----+without |and Bolts.
| | Frac. | Dec.|Flange. |
--------+----------+-------+-----+--------+----------
2 | 5/8 | 3/8 | .373| 6.96 | 4.41
3 | 5/8 | 13/32 | .396| 11.16 | 5.93
4 | 11/16 | 7/16 | .420| 15.84 | 7.66
5 | 3/4 | 7/16 | .443| 21.00 | 9.63
6 | 3/4 | 15/32 | .466| 26.64 | 11.82
8 | 13/16 | 1/2 | .511| 39.36 | 16.91
10 | 7/8 | 9/16 | .557| 54.00 | 23.00
12 | 15/16 | 19/32 | .603| 70.56 | 30.13
14 | 1 | 21/32 | .649| 89.04 | 38.34
16 | 1-1/16 | 11/16 | .695| 109.44 | 47.70
18 | 1-1/8 | 3/4 | .741| 131.76 | 58.23
20 | 1-3/16 | 25/32 | .787| 156.00 | 70.00
22 | 1-1/4 | 27/32 | .833| 182.16 | 83.05
24 | 1-5/16 | 7/8 | .879| 210.24 | 97.42
26 | 1-3/8 | 15/16 | .925| 240.24 |113.18
28 | 1-7/16 | 31/32 | .971| 272.16 |130.35
30 | 1-9/16 |1 |1.017| 306.00 |149.00
32 | 1-5/8 |1-1/16 |1.063| 341.76 |169.17
34 | 1-11/16 |1-1/8 |1.109| 379.44 |190.90
36 | 1-3/4 |1-5/32 |1.155| 419.04 |214.26
38 | 1-13/16 |1-3/16 |1.201| 460.56 |239.27
40 | 1-7/8 |1-1/4 |1.247| 504.00 |266.00
42 | 1-15/16 |1-5/16 |1.293| 549.36 |294.49
44 | 2 |1-11/32|1.339| 596.64 |324.78
46 | 2-1/16 |1-3/8 |1.385| 645.84 |356.94
48 | 2-1/8 |1-7/16 |1.431| 696.96 |391.00
--------+----------+-------+-----+--------+----------
FLANGE SIZES FOR EXTRA HEAVY PIPE.
Adopted by a Conference of Manufacturers, June 28, 1901.
-------+--------+----------+------------+---------+--------
Size of|Diam. of|Thickness |Diameter of |Number of|Size of
Pipe. |Flange. |of Flange.|Bolt Circle.|Bolts. |Bolts.
-------+--------+----------+------------+---------+--------
Inches.|Inches. | Inches. | Inches. | |Inches.
2 | 6-1/2 | 7/8 | 5 | 4 | 5/8
2-1/2| 7-1/2 | 1 | 5-7/8 | 4 | 3/4
3 | 8-1/4 | 1-1/8 | 6-5/8 | 8 | 5/8
3-1/2| 9 | 1-3/16 | 7-1/4 | 8 | 5/8
4 | 10 | 1-1/4 | 7-7/8 | 8 | 3/4
4-1/2| 10-1/2 | 1-5/16 | 8-1/2 | 8 | 3/4
5 | 11 | 1-3/8 | 9-1/4 | 8 | 3/4
6 | 12-1/2 | 1-7/16 | 10-5/8 | 12 | 3/4
7 | 14 | 1-1/2 | 11-7/8 | 12 | 7/8
8 | 15 | 1-5/8 | 13 | 12 | 7/8
9 | 16 | 1-3/4 | 14 | 12 | 7/8
10 | 17-1/2 | 1-7/8 | 15-1/4 | 16 | 7/8
12 | 20 | 2 | 17-3/4 | 16 | 7/8
14 | 22-1/2 | 2-1/8 | 20 | 20 | 7/8
15 | 23-1/2 | 2-3/16 | 21 | 20 |1
16 | 25 | 2-1/4 | 22-1/2 | 20 |1
18 | 27 | 2-3/8 | 24-1/2 | 24 |1
20 | 29-1/2 | 2-1/2 | 26-3/4 | 24 |1-1/8
22 | 31-1/2 | 2-5/8 | 28-3/4 | 28 |1-1/8
24 | 34 | 2-3/4 | 31-1/4 | 28 |1-1/8
-------+--------+----------+------------+---------+---------
INDEX
TO PART TWO
“_An index is something intended to point out, guide, or direct, as the
hand of a clock or a steam-gage, the style of a sun dial, an arm of a
guide-post or the figure of a hand_ ☞.”
THE INDEX
TO PART TWO OF ROGERS PUMPS AND HYDRAULICS.
PAGE
=Accidents=, to avoid, 374
=Acid=, muriatic fumes, action of, 380
syphon pump, ills. and des., 265
=Adjusting=, care must be exercised in, 372
“=Admiralty=,” the rectangular surface condenser, des., 303
=Advantages of the Cataract mining pump=, 146
modern pulsometer, 273
=Aer=, def., 179
=Aëriform fluids=, def., 15
=Aermotor pumps=, 177-192
=Aermotors=, why so named, 187
=Ahrens steam fire engine=, 126
=Air=, des., 15
and steam, relative space occupied by, 378
and vacuum pumps, ills. and des., 31
steam end of, 35
table of test, 41
as a mechanical agent, 17
=Air=, moving power; note, 23
“back pressure” of, des., 36
=Air-bound pumps=, 371
=Air brakes=, use of compressed air in, des., 57
chamber, to prevent freezing, 381
=Air compressor=, direct acting steam single, ills. and des., 72
power wall or post, ills. and des., 72
=the “Imperial,“= ills. and des., 67-70
=Air compressors=, des., 57-78
methods of driving, 59
theoretical operations of, 63
=Air cooler of condenser=, ills., 312
=Air=, fluid of, def., 17
gravity and elasticity of, 16
leaks in suction must be prevented, 374
=Air lift pump=, ills. and des., 79-90
care and management, 87-88
lift system, advantages of, 79
theory of, 80
liquid, des., 64
pipe of a compressor, 84
pressure pumps, direct, ills. and des., 90
=Air pump= attached to a condenser becomes a vacuum pump, 373
Dean Brothers’ twin cylinder, ills. and des., 46-50
Edwards, ills. and des., 53-55
principles of duty, 373
simplest form of, ills., 15
used in connection with a jet condenser, ills., 34
hand, des. and ills., 29, 30
the inertia of, 17
=Altitude=, effect of, on atmospheric pressure, 73, 74
=American pump= as attached to steam fire engine, ills., 93
driving mechanism of, ills. and des., 93, 98
=American steam fire engine pump=, ills., 132, 133
des., 138, 139
=Ammonia or acid pumps=, ills. and des., 171
muriate of, action, 379
=Amoskeag fire engine=, ills., 107, 128
des., 141, 142
=Anderson steam trap=, des. and ills., 332, 333
=Anti-freezing device=, ills., 382
=Application of packing=, how done, 372
=Appurtenances= belonging to steam fire engines, list of, 111
=Aqua-thruster=, 267-269
=Atmosphere=, pressure of, def., 16, 36
surface condenser exerts, 314
weight of, on the surface of the earth, 19
=Atmospheric air=, a type of other gases, 25
=Atmospheric pressure=, effect of altitude upon, 73, 74
pumps, des. and ills., 169-171
=Attachment=, def. of, 317
=Attraction= of cohesion, def., 16
=Automatic action of the pump= controlled by a float, ills. and
des., 318, 319
duplex steam pump and receiver, Deane, ills. and des., 318, 319
throttle valve for boiler feed pump, ills. and des., 352, 353
“=Back pressure=” of atmosphere, des., 36
=Baffle plate=, used in condenser, ills. and des., 305
=Ballast pump=, the, ills. and des., 159-161
=Ballast tank=, ship’s, def., 322
=Ball cock=, ills. and des., 320
=Ball float=, ills. and des., 318-319
how attached in air and vacuum pump, 36
=Ballot, Buys, law= relating to barometers, 181
=Bark=, care to keep out of pipes and valves, 379
mixture, des., 379
white oak, prevents boiler incrustation, 379
=Barometer=, ills. and des., 20
water, how made, 31
=Barrel=, capacity of in gallons, 323
=Bell and spigot= connection, ills. and des., 367
=Belted duplex air compressor= (built by the Allis-Chalmers Co.),
62-71
=Bilge pump=, special fittings for, 161
=“Blake” compressor=, 73
=Bliss-Heath atmospheric pumping engine=, ills. and des., 169-171
=Blowing engine=, ills. and des., 66, 67
=Blow-off cock=, des., 347
valve, Bordo, ills. and des., 354, 355
=Boggs & Clark hydraulic dredging pump=, ills. and des., 217, 218
=Boiler cleaners=, mechanical, 380
compound, cost of, 378
action of, 379
=Boiler compound=, directions for use, 378
for locomotives, 378
formula for, 380
feed pump, centrifugal form adopted for, 222
=Boiler of steam fire engine=, des., 99
=Boiler of the Ahrens steam fire engine=, 126
the Clapp & Jones steam fire engine, 118
the Silsby steam fire engine, 115
=Boiler scale=, table of analysis, 328
=Boilers=, ball cock attached to, 320
corrosion of, how caused, 380
=Bolt circles of= standard pipe flanges; Table, 399
=Bolts=, diameters of; lengths of, 399
=Bordo blow-off valve=, ills. and des., 354, 355
=Bottoming-tap=, ills. and des., 339
=Box wrench=, des., 345
=Brewers’ grains=, how pumped; note, 202
=Buffalo, the centrifugal pump=, ills. and des., 223
=Bulkley “Injector” condenser=, ills. and des., 308, 309
=Buys Ballot’s law relating to barometers=, 181
=Byron Jackson Machine Co.’s turbine pumps=, ills. and des., 236-242
=Cameron=, the, vertical plunger sinking pump, ills., 150-151
des., 152
=Capacity of cisterns and tanks=, how estimated, 364
=Carbonate of lime in boiler scale=, 328
magnesia in boiler scale, 328
=Carbonates deposited= in order, des., 380
=Care and management of air pumps=, 87-88
the Clapp & Jones steam fire engine, 123
=Carr steam pump governors=, ills. and des., 288-291
=Cataract steam pump=, ills., 144
des., 146
=Centrifugal pump=, diagram of right and left-hand methods of
discharge, 225
early form of, ills., 212
des., 214
four stage, ills. and des., 224
important note relating to speed of; quotation from “Industries”,
223-229
Morris Machine Company’s, steam-driven, ills. and des., 220-221
multi-stage, ill. and des., 223-224
the Buffalo, ills. and des., 223
the converse of the turbine water-wheel, 213
vertical, submerged type of, ills. and des., 222-223
directions for erecting and running, 226-228
fans used in, ills., 213
des., 215
history of, 211
=Centrifugal pumps=, how to determine right or left-hand pumps, 226
ills. and des., 211-230
rotary and, 193-229
the Worthington, divided into Conoidal, volute and Turbine,
des., 229
two general types of, ills. and des., 215-216
=Centrifugal wheel=, ten thousand horse power, ills. and des., 213
also 133, Part One.
=Chain tongs=, 343
=Chlorides deposited in order=, des., 380
=Churning in pumps=, causes of, 375
=Churn valve= for feeding the steam fire engine, des., 111
purposes of, 137
=Circulating pump=, des., 32
=Circulating pumps=, ills., 219
des., 168
=Cistern=, def. of, 321
=Cisterns and tanks=, table of capacity for, 324
ball cock attached to, 320
=Cisterns=, computation for finding weight of, 324
contents of round; Table, 398
diameters of, in decimals of a foot; Table, 398
rule for finding contents of round; Table, 398
=Clapp & Jones steam fire engine=, 118
Village Engine, 121
=Classification of steam fire engines=, 93
=Cleaner, mechanical boiler=, 380
=Cleaning carpets and railroad cars and seats=, use of vacuum or
atmospheric pressure in, des., 59
=Cleanliness essential=, 371
=Clogging of suction=, effect of, 374
=Closed pressure tanks=, ills. and des., 321-323
=Coal, decreasing supply of=, 84
=Cock=, des., classes of, 347
ball, ills. and des., 320
blow-off, des., 347
cylinder, des., 247
feed, des., 347
four-way, des., 347
gage, des., 347
oil, des., 347
=Cock=, self-closing, des., 347
steam, des., 347
stop, des., 347
three-way, des., 347
=Cock=, try, des., 347
water, des., 347
=Column of water=, pressure of; Table, 396
=Columns, mine pump=, ills. and des., 363
=Compound, boiler=, record of results, 378
=Compound= or two-stage compression, 74-75
=Compounds= for making pipe joints, 367
=Compressed air=, des., 57
=Compressibility of gases=, 26
=Compression, compound=, or two-stage, 74-75
=Compressor, belted duplex air= (built by the Allis-Chalmers Co.),
62-71
“Imperial” air, des. and ills., 67-70
Norwalk compound, des. and ills., 77-78
=Norwalk standard=, ills. and des., 56-58
power wall or post air, ills. and des., 72
vertical duplex, 64-71
=Compressors, air=, des., 57-58
=Computation for finding weight of water in cisterns and tanks=, 324
obtaining the contents of a barrel in gallons, 324
Miner’s Inch, with ills., 388
open stream measurement, 390
weir dam, water, measurement, 390
relating to water pumped by windmill, 191
“=Condensation=,” def., 18
=Condenser=, def., 32
des., 299
advantages of, 300, 378
combined, and feed-water heater, ills. and des., 306
cone, ills., 312
Conover, ills. and des., 50-53
economy of, 37
elbow, exhaust and injection, des. and ills., 306
exhaust pipe into suction, ills. and des., 381
exhaust steam induction, des. and ills., 308
=Condenser, jet=, ills. and des., 312
jet type of, 33
keel, what it consists of, 311
plant, marine, ills. and des., 310-311
pump, ills. and des., 306-307
=Condensers=, classification of, 303
=Condenser=, surface, ills. and des., 313
tube, ills. and des., 305
=Condensing apparatus=, des. and ills., 297-314
engines, early, des., 378
=Condensing surface= required, amount of, 312-314
=Cone=, condenser, ills. and des., 306
=Conoidal centrifugal pump=, the Worthington, why so named, des., 229
=Conover condenser=, ills. and des., 50-53
=Construction of the Silsby steam cylinder pump and boiler=, 115
=Contamination of water= to be prevented, 375
=Contents, Table of=, XI.
=Controller, Mullin’s automatic=, ills. and des., 352-353
=Cooling towers=, des., 33
=Corcoran double action= suction force pump, des. and ills., 185-186
tank valves, 323
=Corcoran windmill=, ills. and des., 184-186
=Corrosion=, def., 328
how prevented, 380
of boilers, how caused, 380
=Cotton presses=, pump for, ills. and des., 154-155
=Coupling pipe=, ills., 368
“=Crane-necked=” steam fire engine, 141
=Cranes and hoists=, use of compressed air in, des., 57
=Crow=, ills. and des., 340
=Cubic foot=, capacity of in gallons., 323
=Cutter, pipe=, ills. and des., 338
=Cylinder-cock=, des., 347
=Cylinders=, contents of, in cubic feet for each foot depth;
Table, 398
relieved before removing head, 383
=Dam, Weir, measurement= of water, 390
=Dart= union, ills. and des., 367
=Davidson marine pump=, ills. and des., 156-157
=Dean Brothers’= twin cylinder air pump, ills. and des., 46-50
=Dean automatic duplex steam pump and receiver=, ills. and
des., 318-319
single sugar-house pump, ills. and des., 164-165
single vertical sinking pump, ills., 148
des., 149
vacuum pump, ills. and des., 42-43
=Deep-well pump=, working barrel of, 192
=Deflector=, water circulating, 120
=Derangement of duplex pump=, broken valve may cause it, 376
=Diagram of discharge openings= of centrifugal right and left-hand
pumps, 225
=Dial=, to read the, of a water meter, ills., 332
=Diameters of cisterns= in decimals of a foot; Table, 398
=Diaphragm lift and force pump=, ills., 145
des., 148
outfit for, 149
=Diffusion of gases=, 27
vanes of Worthington centrifugal pump, des., 233
=Direct acting steam single air compressor=, ills. and des., 72
=Disadvantages= in the use of compressed air for operating mining
pumps, 71
=Discharge per minute= under given heads; Table, 392-393
=Discovery of the advantages arising from the condensation of
steam=, 300
=Distributing reservoir=, def., 322
=“Doctor” independent pump=, ills. and des., 161-162
=“Donkey” pump=, des., 161
=Double extra first steam fire engine=, capacity and weight of, 93
tube injector, universal, ills., 262
des., 264
=Drain for steam pipes=, 374
=Drain=, necessity for, 374
=Draining pump cylinders and pipes=, 377
plugs, 377
=Dredge=, elevator, des., 222
20-inch hydraulic, ills. and des., 221
=Dredges=, self-propelling and sea-going, des.; note, 210
=Dredging pump=, hydraulic, Boggs & Clark, ills. and des., 217-218
Root’s large rotary, ills. and des., 208-210
=Drill and pipe tap combined=, 339
=Drip cocks=, proper location of, 376
=Dry cocks=, centrifugal pump, particularly adapted for use in
building sewers, in sand dredging, 214
=Duplex pump=, delays, avoid by frequent inspections, 376
derangements of one side, 375
jerky motion in, cause of, 376
repairs should be prompt and timely, 376
screens, important that they be kept clean, 376
separating chamber requires frequent examination, 376
suction valves require much attention, 376
worn parts should be replaced, 376
=Duplex steam pump and receiver=, Deane automatic, ills. and
des., 318-319
=Edison Manufacturing Co.= hand mining pump, des., 148
=Edwards air and vacuum pump=, ills. and des., 53-55
=Ejector=, ills. with a foot strainer, 260
double tube, ills. and des., 261
or exhauster used for priming centrifugal pumps, des., 216
ills., 218
pump, ills. and des., 259-260
water pressure, ills. and des., 266
and injectors, 243-266
application of, ills., 256
des., 260
=Elastic fluids=, two classes of, 16
=Elasticity=, def., 26
a property of air, 16, 17
of all aëriform fluids, def., 17
=Elbow, condenser=, exhaust and injection, des. and ills., 306
pipe, ills., 368
=Elbows=, des., 364
=Electric mining pump=, ills., part one, 276
des., part two, 147
=Elevator=, Mason, pump pressure regulator, ills. and des., 286-287
=Endicott’s platform springs=, des., 141
=Energy of the steam injector=, whence derived, note, 247
wind as a source of power, 181
=Engines=, early condensing, des., 378
=Engine, steam fire=, ills. and des., 91-142
=Entering or taper tap=, ills. and des., 339
=Evaporation=, def. and laws of, 28
=Eve, J., inventor of Eve’s rotary pump=, historical note, 196
=Eve’s rotary pump=, des. and ills., 196-197
=Exhaust steam induction condenser=, des. and ills., 308
injector, ills. and des., 249, 255-256
injector, high pressure, ills. and des., 257
=Exhaust steam=, utilizing of; note, 35
=Expansibility of gases=, def. and ills., 25
=Expansion and compression of a body=, def., 18
=Explanations of principles involved in feeding tank=, 373
exposed pipes, precautions against freezing, 377
=Extra first steam fire engine=, capacity and weight of, 93
=Failure of pump=, how to find cause, 374
=Fans=, ills., 213
des., 215
=Feed-cock=, des., 347
=Feeding into bottom of tank= requires less power than top, 373
=Feed-water heater and combined condenser=, ills. and des., 306
=Volz=, ills. and des., 304-306
impurities, des., note relating to, 327
=Fifth steam fire engine=, capacity and weight of, 93
=Fire engine=, Silsby steam, des. and ills., 113
steam, ills. and des., 91-142
=Fire hose flow of water=, how retarded in, des., 135
pumps, Holyoke pattern of rotary, 203
=First steam fire engine=, capacity and weight of, 93
=Flange joint=, ills., and des., 363
=Flanges=, diameters of standard; Table, 399
standard, bolt circles of; Table, 399
table of standard sizes, 399
thickness of standard, 399
union, des. and ills., 363
=Float=, automatic action of the pump controlled by a, ills. and
des., 318-319
=Flow of water over Weir dam=; Table, 391
=Fluid=, particles of, 14
=Flume=, mechanism to shut off the water supply of, ills., 295
=Foot-board= of the steam fire engine, des., 111
=Foot valve= applied to centrifugal pump, 216
=Forcer of steam injector=, 247
=Foundations of tanks=, 323
suitable, precautions for, 371
=Fountain, Hero’s=, ills. and des., 23
=in vacuo=, ills. and des., 23
=Four stage centrifugal pump=, ills. and des., 224
=Fourth steam fire engine=, capacity and weight of, 93
=Four-way cock=, des., 347
=Fox boiler=, des. and ills., 101-103
=Freeman, John R.=, credit given for table, 117
=Freezing=, anti-, device, 381
of pipe, how prevented, ills. and des., 381
=Friction=, different kinds of pipe, 377
=Friction heads=; Table, 394-395
in small pipes; Table, 397
=Friction=, influence of, on different kinds of pipe, 377
loss in pounds pressure; Table, 392-393
must be kept down, 372
=Frizell system of air lift pumps=, 88
=Gage-cock=, des., 347
=Gallon=, capacity of, 323
imperial, capacity of, 323
=Gallons for each foot of length in pipes=, 398
=Gases and liquids=, properties in common, des., 24
compressibility of, 26
diffusion of, 27
expansibility of, def. and ills., 25
permanent, def., 16
pressure exerted by, 26
weight of, def., 26
=Gas-fitter’s air proving pump=, def. and ills., 29
=Gates=, head, mechanism to raise and lower, ills., 295
=Gauge, hydraulic, test pump=, ills. and des., 164
indicating pressure and vacuum, des., 259
vacuum, why graduated in inches; note, 21
=Giffard, Inventor of the injector=; historical note, 245
=Gould’s rotary pump=, ills., 194
des., 199
=Governor= and pump, des. and ills., 317-319
=Governors, Carr steam pump=, ills. and des., 288-291
=Governor, Mason pump=, ills. and des., 284-286
utility combination pump, des. and ills., 296
=Governors=, pump speed, ills. and des., 281-294
=Graduated tank=, des., 322
=Grains=, wet, brewers’, how pumped; note, 202
=Graphite as a lubricant=, des., 384
=Graphite=, invaluable about studs, nuts, etc., 384
mix with oil for hand pump, 375
use of, on pipe threads, 384
=Gravitation=, effect on current of air, 180
=Gravity=, a property of air, 16
=Grit=, avoid in packing, 377
=Guericke, Otto von=, inventor, 19
=Guide vanes of Worthington centrifugal pump=, des., 231
des., 212
=Hammer=, how best used, des., 345
=Hand air pumps=, des. and ills., 29-30
=Harris system of raising water by= direct pressure, 90
=Hayden & Derby Mfg. Co.=, 252
=Head gates=, mechanism to raise and lower, ills., 295
=Heads=, friction at given rates; Table, 394-395
=Heat=, action of, on particles of bodies, 16
=Heater=, noiseless water, ills. and des., 265-266
stationary, for the steam fire engine, 105
=Heron or Hero=, account of, 99
of Alexandria; historical note relating to steam fire engine, 95
“=Hero’s fountain=,” invented by Hero of Alexandria, 99
ills. and des., 23
“=Hessian Suck=,” a form of centrifugal pump, des., 211
=Hinged valve=, 347
=Historical notes= and ills. relating to steam fire engine, 92-99
=History of the centrifugal pump=, 211
=Hogshead=, capacity of, 323
=Holyoke improved speed governor for water wheels=, ills. and
des., 291-294
pattern rotary pump, 203
=Horizontal two-stage pump=, ills., 236
des., 241
=Hydraulic dredge=, 20-inch, ills. and des., 221
dredging pump, Boggs & Clarke, ills. and des., 217-218
gauge test pump, ills. and des., 163
joints for high pressure, ills. and des., 361
=Hydraulic lifts and cranes=, pump for, des. and ills., 154-155
packing, difficulty in cutting, 373
pipes, best way to join; Note, 367
riveting and punching, pump for, ills. and des., 154-155
=Hydro-pneumatics=, 15
=Ice=, expansion of, 381
=Ideal steel tank tower=, ills. and des., 187
“=Impellers=,” des., 212
=Impellers of Worthington centrifugal pump=, des., 233
=Impellers or pistons of rotary pumps=, ills. and des., 196
=“Imperial” air compressor=, ills. and des., 67-70
=Imperial gallon=, capacity of, 323
=Incrustation=, des., 328
=Incrustations of injector pipes=, how removed, 254
=Injection=, def., 32
water of air and vacuum pumps, des., 35
=Injector=, action of, 247, 249
a gauge indicating both pressure and vacuum for the, 259
=“Injector” condenser, Bulkley=, ills. and des., 308-309
=Injector, double tube universal=, ills., 262
des., 264
exhaust steam, ills. and des., 255-256
high pressure exhaust steam, ills. and des., 257
how to start the exhaust steam, 259
Korting, des., 264
“Manhattan” automatic, ills., 244
des., 251
Metropolitan double tube, ills., 248
des., 252
Metropolitan single tube, ills., 250
des., 252
Monitor, ills., 246
des., 252
not an economical device, 249
peerless automatic, ills., 246
des., 251
peerless, names of parts, 251
ills., 234
peerless, table of pressure and temperature of the, 251
the exhaust steam, 249
=Injectors and ejectors=, 243-266
piping of “Manhattan” and peerless, ills. and des., 253
rules to govern the actions, etc., of, 253-254
table of capacity of, 252
three distinct types of, 247
=Inspection for causes of failure in starting a pump=, 371
=Inspections, internal and external necessary=, 374
=Inspirator=, des., 249
=Instructions and suggestions for the steam fire engine=, 129,
131, 135-137
=Interchangeable socket wrench=, ills. and des., 344
=Inter-cooler, the=, ills. and des., 74-78
=Intermediate tap=, ills. and des., 339
=Interruption of flow by foreign body in suction=, 375
=Inverted-cup valve=, 347
=Irregularity in duplex pump=, cause of, 375
=Irregular speed= indicates trouble, 376
Duty, unsteady discharge requires attention, 376
=“Isochronal” pump=, def., 147
=Jet condenser=, ills. and des., 32, 303, 312
discovery of, 301
=Jet pump=, the, ills. and des., 261
type of condenser, 33
=Joint, pipe, compounds for making=, recipes, 362
piping, des. and ills., 359-362
=Keel condenser=, what it consists of, 311
=Kerosene=, effect on pipe joints, 362
=Key valve=, 47
=“Kicking down” a well in the early days=, ills., VIII.
=Knight, E. H.=, classification of cocks and valves, 347
=Korting injector=, pieces composing the, shown in cuts page, 263
names of the parts, 264
=La France steam fire engine pump=, ills., 134
des., 139-141
=Leakage=, indications of, 376
slight, unimportant, 373
=Leaks=, often the cause of failure in starting a pump, 371
=Left and right-hand pumps=, customary rule for, 371
=Life of boiler of steam fire engine=, how prolonged, 105
=Lifter of steam injector=, 247
=Lifting valve=, 347
=Lime=, carbonate of, in boiler scale, 328
=Liquid air=, des., 64
=Liquids under heavy pressure=, pump for delivering, ills. and
des., 154-155
=Lobes of rotary pump=, ills. and des., 209-210
=Location for pumps=, proper, 371
=Lombard, Nathaniel=, pump governor; note, 294
=Lubrication=, intermittent, to be avoided, 375
=Lubrication=, proper, for packing, 373
=Magdeburg cups or hemispheres=, ills. and des., 19
=Magma sugar pump=, ills. and des., 166-167
=Magnesia=, carbonate of in boiler scale, 328
salt, etc., in water, 380
must be removed, 380
=Main feed pump, uses for the=, 161
=“Manhattan” automatic injector=, ills., 244
des., 251
=Marine pump=, Davidson pattern, ills. and des., 156-157
=Marine pumps=, 155-162
Ship’s pump, 155
“=Mariotte’s law=”, 17
=Marks of parts necessary=, 374
=Maslin automatic steam vacuum pump=, ills., 271
des., 279
=Mason elevator pump= pressure regulator, ills. and des., 286-287
pump governor, ills. and des., 284-286
pump pressure regulator, ills. and des., 349-350
steam pump with receiver attached, ills. and des., 319
water reducing valve, ills. and des., 351
“=Massachusetts pump=,” des., 211
=Matter=, properties of, 24
=Measurements of pipe lines=, how to be taken, ills., 368
=Mechanical boiler cleaners=, 380
=Mercury=, inches of, def., 31
=Metallic packings=, popular and good, 377
=Meter=, water, ills. and des., 329-332
Worthington water, ills. and des., 330-332
=Meteorology=, def., 179
=Metropolitan= double tube injector, ills., 248
des., 252
single tube injector, ills., 250
des., 252
=Mine drainage=, adaptation of the turbine pump for, 233
pump columns, ills. and des., 363
=Miner’s inch water measurement=, ills., 388
=Mining, Cataract steam pump=, ills., 144
des., 146
=Mining pump=, double leather, ills., 145
des., 147
electric, ills., Part One, 276
des., Part Two, 147
hand-power, ills., 145
des., 148
the Cameron vertical plunger sinking, ills., 150-151
des., 152
the “Scranton,” ills. and des., 153-154
=Mining pumps=, des. and ills., 145-155
pumps, an advantage of; note, 152
note relating to the cost of repairing a half-inch globe valve, 145
use of compressed air in, 71
=Miscellaneous pumps=, 143-176
=Molecules=, repulsive force of, 27
=Monitor injector=, ills., 246
des., 252
=Monkey-wrenches=, “knife-handle,” ills. and des., 344
=Morris Machine Company’s centrifugal pump=, steam-driven, ills. and
des., 220-221
=Mud=, 20-inch hydraulic dredge for pumping mud, silt, etc., 221
=Mullin’s Automatic controller=, ills. and des., 352-353
=Multi-stage centrifugal pump=, ills. and des., 223-224
turbine pump, priming of, ills. and des., 228-229
=Neck-cap of the modern pulsometer=, ills. and des., 274
=Neck-piece of the modern pulsometer=, ills. and des., 274
=Newcomen=, discovery relating to condensation of steam, 301
=Nipple-Holder=, pipe, ills. and des., 341
=Norwalk compound compressor=, des. and ills., 77-78
standard compressor, ills. and des., 56-58
note, 78
=Nozzles of steam fire engine=, 125
three types of, in steam injector, 247
=Nuts and screws= must be kept tight, 374
=Oak-bark=, directions for use, 379
white, used in boilers, 379
=Oil-cock=, des., 367
=Oil=, how used in the Cataract steam pump cylinder, 146
=Oil-pipe lines=, pump for, 155
tank steamer pump, ills. and des., 159-161
=Packing=, care of, 372
economy of, narrow rings, 372
for pump plungers, 373
for pumps, suitable, 372
how to fit, 372
must be elastic, never rigid, 372
for stuffing boxes, badly proportioned, glands too short, 372
to cut square thinner, des. and ills., 383
=Paper mills=, particularly adapted for use of centrifugal pumps, 214
=Papin, Denis=, inventor, account of, 211
historical note, 64
=Parallel vise=, 341
=Parker, Richard Green=, quotation, 14
=Peerless automatic injector=, ills., 246
des., 251
=Pelton water wheel=, 60
=Pilot or auxiliary valve=, des., 348
=Pipe=, condenser spray, des., 306
connections, proper arrangements of, 363
cutter, ills. and des., 338
fitting, des., 359
freezing of, how prevented, ills. and des., 381
gas and steam, how measured, 367
joint, des. and ills., 359-363
telescopic, ills. and des., 152
=Pipe lines=, how measurements are to be taken, ills., 368
lines, steam, 364
=Pipe=, making up a piece of, 363
nipple holder, des., 341
originally a musical wind instrument, 359
saddles for quick connections into pipes, ills., 382
spanner, ills. and des., 344
stock and die, des., 341
=Pipe=, suction, should be drained, 377
tail, of condenser, ills., 312
thickness of standard, 399
=Pipe tongs=, ills. and des., 343
vise, ills. and des., 340
=Pipe=, wooden, note relating to, 364
wrench, Trimo, ills. and des., 343
advantages and disadvantages of, 377
=Pipes and fittings=, note relating to, 359
exposed, precautions against freezing, 377
flow of water in cast iron; table, 394-395
joints and fittings, 359-368
relative advantages of, 377
=Pipes=, small, rates of discharge; table, 397
steam, to properly drain, 374
strainers for suction, ills. and des., 325-328
=Piping of Manhattan and peerless injectors=, ills. and des., 253
of high pressure exhaust steam injector, ills. and des., 258
standard, “extra strong,” double extra strong, ills. and des., 367
to remove incrustations from injector, 254
=Piston, Follower type=, how packed, 383
=Plug pipe=, ills., 368
taps, ills. and des., 339
=Plugs=, drain, 377
=Plunger=, deep well pump, ills. and des., 192
packing, dry, remedy for, 377
packing, how to apply, 373
water, how packed, des. and ills., 383
=Pneumatics=, 15-30
=Pneumatic syringe=, ills. and des., 26
=Pohle, Dr. Julius J.=, historical note, 79
system of elevating liquids, ills. and des., 81-84
“=Points=” relating to the care and management of air compressors, 61
=Portable drilling machines=, use of compressed air in, des., 57
form of pulsometer and boiler, ills. and des., 280
tool, def., 337
=Ports=, reducing capacity of, by substances, 375
=Power of a windmill=, what it depends upon, 190
wall or post air compressor, ills. and des., 72
=Practical Engineer=, ills. of air lift pump from, 89
=Preface=, IX
=Pressure, atmosphere=, surface condenser exerts, 314
exerted by gases, 26
in pounds for every foot up to 300 ft. height, etc.; Table, 396
of air and gases, def., 17
of column of water; Table, 396
of the atmosphere, def., 16
=Pressure per square inch= in pounds; Table, 396
reducing valve, ills. and des., 349-350
=Prime movers=, def., 181
=Priming methods= adopted to suit centrifugal pumps of various
designs, ills. and des., 228-229
=Priming=, to start, 377
=Propeller pump=, the wood, ills. and des., 172-174
=Pulsator=, 269
=Pulsometer=, des. and ills., 267-280
=Pulsometer=, action of, 276-277
a form of vacuum pump, 269
and boiler in portable form, ills. and des., 280
arrangements of, for emptying vats or tanks, ills. and des., 278
historical, 269
important points to be attended to; note, 279
=Pulsometer=, suggestions relative to placing of the pump; note, 273
the modern, ills. and des., 270-273
the original, ills. and des., 268-271
the principal parts of, des. and ills., 277
=Pump=, air, Dean Brothers’ twin cylinder, ills. and des., 46-50
air lift, ills. and des., 79-90
=Pump, American=, driving mechanism of, ills. and des., 93, 98
and governor, des. and ills., 317-319
Buffalo centrifugal, ills. and des., 223
centrifugal, diagram of right and left-hand methods of
discharge, 225
centrifugal, four-stage, ills. and des., 224
multi-stage, ills. and des., 223-224
vertical, submerged type of, ills. and des., 222-223
=Pump=, circulating, des., 32
columns, mine, ills. and des., 363
Conover vacuum, ills. and des., 50-53
Corcoran double action suction force pump, ills. and des., 185-186
Davidson, marine, ills. and des., 156-157
Dean single vertical sinking, ills., 148
Dean vacuum, ills. and des., 42-43
deep well, working barrel of, 192
=Pump, difference= between a hand pump and a windmill pump, 187
=Pump, Edwards’ air=, ills. and des., 53-55
ejector, as a form of, 259
Eve’s rotary, des. and ills., 196-197
=Pump=, failure in starting, cause, 371
for salt water evaporator and distiller, ills. and des., 168
=Pump=, gas-fitter’s air proving, def. and ills., 29
Gould’s rotary, ills., 194
des., 199
=Pump governor, Mason=, ills. and des., 284-286
Nathaniel Lombard, note, 294
utility, combination, des. and ills., 296
=Pump governors, Carr steam=, ills. and des., 288-291
hand oil, desirable, 375
“=Hessian Suck=,” des., 211
hydraulic gauge test, ills. and des., 163
=Pumping water=, use of compressed air in, des., 59
“=Isochronal=,” def., 147
=Maslin automatic steam vacuum=, ills., 271
des., 279
“=Massachusetts=,” des., 211
mining, hand-power, ills., 145
des., 148
=Pump of the Silsby steam fire engine=, 113
portable fire air, 29
=Quimby screw=, ills. and des., 174-176
=Root’s rotary=, ills. and des., 209
=Pump speed governors=, ills. and des., 281-394
=steam fire engine=, ills. and des., 91-142
=American=, ills., 132, 133
des., 138-139
=La France=, ills., 134
des., 139-141
syphon, ills. and des., 188, 265
as attached to steam fire engine, ills., 93
the “=Ballast=,” ills. and des., 159-161
the =Cameron vertical plunger sinking=, ills., 150-151
des., 152
the =Deane sugar-house=, ills. and des., 164-165
the =“Doctor” independent pump=, ills. and des., 161-162
the injector can be used as a, 249
the jet, ill. and des., 261
the =Magna sugar=, ills. and des., 166-167
the =“Scranton” mining=, ills. and des., 153-154
the ship’s, 155
=Taber rotary=, 200-202
=Pumps=, air and vacuum, ills. and des., 31
air pressure, ills. and des., 90
ammonia or acid, ills. and des., 171
auxiliary feed, often duplicated, 161
=Byron Jackson Machine Company’s turbine=, 236-242
=Pumps, centrifugal=, ills. and des., 211-230
circulating, ills., 219
des., 168
directions for erecting and running, 226-228
fire, =Holyoke pattern of rotary=, 203
=Pumps, marine=, 155-162
methods of priming centrifugal pumps, 228-229
=Pumps, mining=, 145-155
an advantage of, note, 152
=Pumps, miscellaneous=, 143-176
of steam fire engine, des. and ills., 100, 106, 107
operation of large dredging, 210
rotary and centrifugal, 193-229
=Pumps, rotary=, ills. and des., 194-210
impellers or pistons of, ills. and des., 196
used for pumping thick stuff, 165
=Pumps, sinking=, des. and ills., 148
“sugar-house”, 165-167
=Taber rotary=, 200-202
turbine, 230-242
vacuum, single and cross compound double acting, 37-39
vacuum, table of arrangement of valves, 41
wind power, ills. and des., 185-192
=Pump=, the wood propeller, ills. and des., 172-174
the =Worthington pressure=, ills. and des., 154-155
the =Worthington “wrecking” pump=, ills. and des., 157-159
vacuum, =Worthington vertical beam=, ills. and des., 44-45
=Pump=, vertical, of the =Clapp & Jones steam fire engine=, 118
windmill, operation of, 187
=Purification of water= effected by the air lift pump, 87
=Purifying water=, 379
=Quimby screw pump=, ills. and des., 174-176
=Raising sunken vessels=, use of compressed air in, des., 59
“=Rarefaction=,” def., 18
“=Rarefied=,” def., 18
=Ratchet drill=, ills. and des., 338
=Rates of discharge= of small pipes; Table, 397
=Reamer=, ills. and des., 339
=Receiver=, use of, 317
Dean, Mason and Worthington steam pumps with receiver attached,
des. and ills., 318-319
=Receiving reservoir=, def., 322
=Rectangular surface condenser=, the “Admiralty,” des., 303
=Refrigerating and ice making=, use of compressed air in, des., 59
=Regulator=, Mason elevator pump pressure, ills. and des., 286-287
=Relieved cylinders=, how to proceed, 383
=Remedy for air-bound pumps=, 371
=Reservoir=, def., 322
distributing, def., 322
receiving, def., 322
=Reynolds-Corliss type=, valve gear of, 67
=Right and left-hand pumps=, how determined, 371
=Rings=, how to cut to size, 373
pattern, to be on hand, 383
=Riveters=, use of compressed air in, des., 57
=Root’s large rotary pump= for dredging purposes, ills. and
des., 208-210
=Rotary and centrifugal pumps=, 193-229
pump driven by steam used for fire purposes, des., 205
ills., 206-207
=Holyoke pattern=, 203
lobes of, ills. and des., 209-210
type used by the Silsby fire engine designers; sliding abutment
of rotary pump, des., 199
ills. and des., 194-210
how divided into classes, 196
impellers or pistons of, ills. and des., 196
speed of, 174
=Rotary steam fire engine, Silsby=, des. and ills., 113
valve, 347
=Rules for approximately determining the size of a windmill= to use
in pumping, 190
for obtaining the contents of a barrel in gallons, 324
for setting of Deane vacuum pump valves, 43
to govern the actions, etc., of injectors, 253-254
=Saddles=, how attached to pipes, des., 382
pipe, substitute for tees, 382
=Sal soda=, use of, 380
=Salts=, magnesia, etc., in water, 380
=Salt water evaporator= and distiller, pump for, ills. and des., 168
Root’s large rotary pump for salt water service, 210
=Sampson windmill=, des., 190
=Sand blasts=, use of compressed air in, des., 57
large rotary pump for, 210
or heavy material for pumping, speed of pump to be increased, 219
=Santovio of Padua=, Italy, inventor of the pulsometer, 269
=Savery, Thomas=, pump, when patented, ills. and des., 268-271
=“Scranton” mining pump=, ills. and des., 153-154
=Screw pump, Quimby=, ills. and des., 174-176
=Schutte & Koerting Co.=, combined throttle and quick closing trip
valve, 348
condenser plant, revised by, ills. and des., 310
=Second steam fire engine=, capacity and weight of, 93
=Self-closing cock=, des., 347
=Self-propelled steam fire engines=, Amoskeag pattern, 142
=Separators=, necessary, 374
=Setting and operating of the Taber pumps=, 200-202
=Ship’s ballast tank=, def., 322
pump, the, 155
pump, the “Donkey,” des., 161
=Shop tools of all kinds=, use of compressed air in, des., 57
=Siamese connection= for stand pipes, 138
=Sight feed cup=, automatic in its operation, 375
proper place for, 375
when to fill, 376
=Sight feed=, oil cups recommended, 375
=Silsby rotary steam fire engine=, des. and ills., 113
=Sinking caissons= and driving tunnels through silt and soft
earth, use of compressed air in, des., 59
=Sinking or station pump=, adaptation of the turbine pump for, 233
des. and ills., 148
Deane single vertical, ills., 138
des., 149
=Size of rings to use=, 373
=Sleeve coupling=, ills. and des., 367
=Slide valve=, 347
=Slippage=, def., causes of, 384
=Socket wrench=, interchangeable, ills. and des., 344
=Spanner=, ills. and des., 344
=Speed controlling device=, style A, Mason pump, method of operating,
ills. and des., 288
=Speed governor for water wheels=, Holyoke improved, ills. and
des., 291-294
pump governors, ills. and des., 281-294
=Spray pipe and nozzle=, ills., 312
=Spring valve=, 347
=Sprinkler=, inside boiler to scatter particles that would otherwise
form scale, 380
=Square packings=, advantages of, 372
=“Staggered” tube system= used in steam fire engine, 104
=Standard pipe sizes=, ills., 367
=Starting a pump=, precautions in, 371
=Steam and air=, relative space occupied by, 378
boiler, feed water impurities, des., 327
cock, des., 347
cylinders, engines and pumps synonymous, require the same
lubrication, 375
driven centrifugal pump, Morris Machine Company’s, ills. and
des., 220-221
end of air and vacuum pumps, 35
=Steam fire engine=, ills. and des., 91-142
auxiliary appliances and supplies, 99
“crane necked,” frame for, 141
Fox boiler, des. and ills., 101-103
historical notes and ills., 92-99
inner and outer tube system, des., 104
instructions and suggestions, 129, 131, 135-137
nozzles, 125
parts of, 99
pumps, des. and ills., 106, 107
pumps, piston rods, exhaust, coal box, etc., 100, 101
self-propelled, Amoskeag pattern, 142
stationary heater for, des., 105
suction strainers of, des. and ills., 109
table of effective fire streams for, 117
“thaw-pipe” connected to, 123
the =Ahrens=, 126
=Steam fire engine= pump, the American, ills., 132, 133
des., 138-139
the =Amoskeag=, ills., 107, 128
des., 141-142
the boiler, des., 99
the =Clapp & Jones=, 118
the =La France=, ills., 134
des., 139-141
=Steam fire engine, the Silsby rotary=, des. and ills., 113
appurtenances belonging to, 111
Siamese connections for, 138
valve motion of, des., 110
=Steam induction condenser=, exhaust, des. and ills., 308
=Steam injector=, exhaust, ills. and des., 255-256
injectors, three distinct types of, 247
mains, bracket for supporting of, ills. and des., 364-365
materials for making, 364
pipe lines, 364
the proper anchoring and supporting of, ills. and des., 365
to properly drain, 374
=Steam pump=, Deane automatic duplex, ills. and des., 318-319
=Steam shovel= of service in raising material, 222
trap, des., 333-334
=Steam=, utilizing of exhaust; note, 35
=Stems= valve, in suction must not leak, 374
=Stock and die pipe=, ills. and des., 341
=Stop-cock=, des., 347
=Stopping at night=, precautions for, 377
=Stop valve=, necessity of, 371
=Stover Manufacturing Company=, makers of the Sampson windmill, 190
=Strainers for suction pipes= of steam fire engines, 138
for suction water pipes, ills. and des., 325-328
suction, of steam fire engine, des. and ills., 109
=Stress on bolts=, 399
=Stuffing boxes=, failure under high pressure, cause, 375
pump end, how lubricated, 375
=Submerged type of centrifugal vertical pump=, ills. and des., 222-223
=Suction hose= for the steam fire engine, how fitted and carried, 111
=Suction pipe= should be drained, 377
pipes, strainers for, ills. and des., 325-328
strainers of steam fire engines, des. and ills., 109
valves must be well packed, 374
=“Sugar-house” pumps=, 165-167
pump, the Deane, ills. and des., 164-165
=Sugar=, action of in boilers, 379
no action on copper, tin, lead and aluminum, 379
=Suggestions how to find the trouble= in starting a pump, 371
=Sulphates= deposited in order, des., 380
=Surface condenser=, 32, 303, 313
extent of a, 28
=Swivel bench vise=, ills. and des., 340
=Syphon pump=, des. and ills., 188
=Syringe, Pneumatic=, ills., and des., 26
=Taber pumps=, directions for settling and operating, 200-202
=Table of= analysis of average boiler scale, 328
arrangement of valves for air and vacuum pumps, 41
average hourly velocity of the wind in the U. S., 183
Bliss-Heath dimensions and capacities of atmospheric pumps, 171
bolt circles of standard pipe flanges, 399
=Table of= capacities at varying heights above sea level, 74
capacities, etc., of the universal double tube injector, 264
and pipe sizes of sugar-house pumps, 167
for 20-inch hydraulic dredge, 221
of “Ballast” pump, 161
of Boggs & Clarke hydraulic dredging pump, 218
of Davidson marine pump, 157
of Deane single sugar-house pump, 165
of injectors, 252
of tanks and cisterns, 324
of the Deane single vertical sinking pump, 149
of Worthington “wrecking” pump, 159
=Table= of classification of steam fire engines, 93
of Contents, XI.
of contents of cylinders in cubic feet for each foot of depth, 398
=Table of= diameters of cisterns in decimals of a foot, 398
dimensions of noiseless water heater, 266
of the Bordo blow-off valve, 356
of water pressure ejector, 266
=Table of= discharge per minute under given heads, 392-393
of effective fire streams, 117
of flow of water in cast iron pipes, 394-395
=Table of= flow of water= over Weir Dam, 391
friction heads at given rates, 394-395
friction heads in small pipes, 397
friction, loss in pounds pressure, 392-393
rates of discharge of small pipes, 397
parts of the “Imperial” air compressor, 70
pressure in pounds for every foot up to 300 ft. height, etc., 396
=Table of= pressure of column of water, per square inch in pounds, 396
of sizes, capacity, etc., of the Cataract steam pump, 147
of sizes, etc., of the “Blake” compressor, 73
sizes and capacities of ejectors, 259
=Table of= standard sizes of flanges, 399
test of air and vacuum pumps, 41
velocity of flow in pipes, 392-393
=Tables and data=, 387-400
dimensions and capacities of the Quimby screw pump, 176
pressure and temperature of the peerless injector, 251
relating to the sizes and capacities of pumping mills, 189-190
=Tail pipe of condenser=, ills., 312
=“Take-off” ring of Fox boiler=, des. and ills., 103
=Tank=, def. of, 321
ball cock, operation of, ills. and des., 320
closed pressure, ills. and des., 321-323
feeding into top or bottom, 373
graduated, def., 322
hoops, lugs and lock nut nipples, important parts of, 323
needed strength of a, 323
valves, 323
=Tanks and cisterns=, 188, 321-324
table of capacity for, 324
arrangements of pulsometer for emptying, ills. and des., 278
computation for finding weight of, 324
foundations for, 323
=Tanneries=, particularly adapted for use in centrifugal pump, 214
=Tap=, ills. and des., 339
“=Tapping=,” des. of process, 339
=Tapping iron furnaces=, use of compressed air in, des., 59
=Tee=, beaded malleable iron, ills. and des., 367
malleable iron, ills. and des., 363
pipe, ills., 368
=Telescopic pipe joint=, ills. and des., 152
=Temperature of gases=, 28
=Ten thousand horse power turbine wheel=, ills., IV
=Test pump=, hydraulic gauge, ills. and des., 163
“=Thaw-pipe=” connected to Clapp & Jones steam fire engine, 123
=Theoretical operations of air compressors=, 63
=Theory of air lift=, 80
=Thermometer=, des., 18
=Thick stuff=, the handling of, des., 165
=Third steam fire engine=, capacity and weight of, 93
=Three-way cock=, des., 347
=Throttle and quick closing trip valve=, ills., 336
des., 348
valve, automatic, for boiler feed pump, ills. and des., 352-353
=Thud=, causes of, in pumps, 375
=Tire air pump=, 29
=Tongs=, chain, 343
pipe, ills. and des., 343
=Tools=, def., 337
valves and piping, 335-356
=Towers=, cooling, des., 33
=Transmitting messages through pneumatic tubes=, use of compressed
air in, des., 59
=Trap=, Anderson steam, des. and ills., 332-333
steam, des., 333-334
=Trimo pipe wrench=, ills. and des., 343
=Try-cock=, des., 347
=Tub=, des., 323
=Tube of condenser=, ills. and des., 305
=Tubing=, including boiler tubes, how measured, 367
=Turbine pump=, multi-stage, how primed, ills. and des., 228
=Turbine pump=, space occupied by; note, 233
pumps, 230-242
Byron Jackson Machine Company’s, 236-242
=Turbine wheel, ten thousand horse power=, ills., IV
=Two-stage or compounded compression=, 74-75
=Union=, Dart, ills. and des., 367
flange, ills. and des., 363
pipe, ills., 368
=Universal double tube injector=, ills., 262
des., 264
=Uses of compressed air=, 57
=Utilities and attachments=, 315-334
=Utility=, def. of, 317
=Vacuum=, def., 31
des., 299
chamber necessary for high lifts, 374
remedy for pounding, 374
gauge, why graduated in inches; note, 21
pumps, single and cross compound double acting, 37-39
table of arrangement of valves, 41
table of test, 41
synonymous with air, 373
the Conover condenser, ills. and des., 50-53
the Deane, ills. and des., 42-43
the Edwards, ills. and des., 53-55
the Maslin automatic steam, ills., 271
des., 279
the Worthington vertical beam, ills. and des., 44-45
=Valve=, def., 347
automatic throttle, for boiler feed pump, ills. and des., 352-353
auxiliary or pilot, des., 348
Bordo blow-off, ills. and des., 354-355
churn, for feeding the steam fire engine, des., 111
connection of, 346
=Valve for Carr steam pump governors=, ills. and des., 290-291
gear of the Clapp & Jones Village Engine, 122
of the Reynolds-Corliss type, 67
heart created on the principles of, 347
hinged, 347
inverted-cup, 347
key, 347
lifting, 347
Mason water reducing, ills. and des., 351
=Valve motion of steam fire engines=, des., 110
pressure reducing, ills. and des., 349-350
rotary, 347
slide, 347
spring, 347
throttle and quick closing trip, ills., 336
des., 348
clogging of, remedy, 375
“Corcoran” tank, 323
lift of, important for high pressures, 375
names, how derived, 347
=Valves of an air compressor=, how operated by mechanical means, 65
rule for setting of Deane vacuum pump, 43
several classes of, 347
suction, must be well packed, 374
=Vat=, des., 323
“=Van Duzen’s steam jet pump=”; note, 260
=Vapor=, def., 16
=Velocity, average of the wind for the U. S.=, 182
of flow in pipes; Table, 392-393
water entering suction, 378
water in discharge pipes, 378
relative, of water in large and small pipes, 378
=Vertical duplex compressor=, 64-71
pump of four-stage turbine, ills., 238
des., 241
=Vise, pipe=, ills. and des., 340
swivel bench, ills. and des., 340
“=Volute=,” def. of, 211
centrifugal pump, the Worthington, why so named, des., 229
centrifugals, des., 229
=Volz combination of condenser and feed-water heater=, ills. and
des., 304, 305, 306
=Water “Ballast” pump=, des. and ills., 160
Barometer, how made, 31
cock, des., 347
contamination of, to be prevented, 375
=Weir Dam measurement=, des. and ills., 390
=Water, discharge per minute under given heads=; Table, 392
expansion of, by freezing, 381
Miner’s Inch, flow of, 388
=Waterhammer=, prevention of, ills. and des., 381
=Water heater=, noiseless, ills. and des., 265-266
meter, ills. and des., 329-332
to read the dial of a, ills., 332
Worthington, ills. and des., 330-332
=Water=, open stream measurement, 390
penetrating force of, under high pressure, 381
plunger, how packed, des. and ills., 383
pressure ejector, ills. and des., 266
pressure of column of; Table, 396
purifying of, 379
reducing valve, Mason, ills. and des., 351
relative velocity of, in large and small pipes, 378
velocity of, in discharge pipes, 378
=Water wheels=, Holyoke improved speed governors for, ills. and
des., 291-294
Turbine, ills., IV
=Water works=, mine drainage, adaptation of the turbine pump for, 233
=Wear of parts=, inspections necessary, 374
=Weather bureaus=, table of the average hourly velocity of wind in
the U. S., 183
=Weight of gases=, def., 26
=Well heads=, three styles of, des. and ills., 86-87
=Westinghouse Electric & Mfg. Co.=, 75-H. P. induction motor, 241
=Wheeler Condenser and Engineering Co.=, referred to, 306
=Windmill governor=, ills. and des., 188
pump, des., 187
operation of, 187
rules for approximately determining the size of, 190
as a prime mover, 182
=Windmills=, note relating to, 183
the Corcoran, ills. and des., 184-186
=Windmill=, the power of, upon what it depends, 190
=Windmotors=, why so named, 187
power pumps ills. and des., 185, 192
power as a source of energy, 181
=Wind produced by gravitation=, 180
average velocity of, for the U. S., 182
=Wooden pipe=, note relating to, 364
=Wood propeller pump=, the, ills. and des., 172-174
=Working, improper=, to find cause of, 375
=Worthington centrifugal pumps= divided into Conoidal, Volute and
Turbine, des., 229
condensing apparatus, operation of, 307
duplex steam pump with receiver attached, ills. and des., 319
pressure pump, the, ills. and des., 154-155
turbine pump, ills. and des., 230
vertical beam vacuum pump, ills. and des., 44-45
water meter, ills. and des., 330-332
“wrecking” pump the, ills. and des., 157-159
=“Wrecking” pump=, ills. and des., 157-159
=Wrench=, def., 345
monkey, ills. and des., 344
interchangeable socket, ills. and des., 344
single-ended, double-ended, open-ended, box-wrench, des., 345
Trimo pipe, ills. and des., 343
=Zinc=, attacked strongly by sugar, 379
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It gives directions and detailed descriptions for running the various
types of steam engines in use.
The book also treats generously upon Marine, Locomotive and Gas
Engines, and will be found valuable to all users of these motive powers.
_Hawkins’ Steam Boiler Practice._ =$2=
This instructive book on _Boiler Room Practice_ is indispensable to
Firemen, Engineers and all others wishing to perfect themselves in this
important branch of Steam Engineering.
Besides a full descriptive treatise on Stationary, Marine and
Locomotive boilers, it contains sixty management cautions, all
necessary rules and specifications for boilers, including riveting,
bracing, finding pressure, strain on bolts, etc., thus being a complete
hand-book on the subject.
_Hawkins’ Mechanical Drawing._ =$2=
This work is arranged according to the correct principles of the art
of drawing; each theme being clearly illustrated to aid the student to
ready and rapid comprehension.
It contains 320 pages with over 300 illustrations, including useful
diagrams and suggestions in drawings for practice. Handsomely bound in
dark green cloth. Size 7 × 10 inches.
_Hawkins’ Calculations for Engineers._ =$2=
The Hand Book of Calculations is a work of instruction and reference
relating to the steam engine, steam boiler, etc., and has been said to
contain every calculation, rule and table necessary for the Engineer,
Fireman and Steam User.
It is a complete course in Mathematics. All calculations are in plain
arithmetical figures, so that they can be understood at a glance.
_Hawkins’ Steam Engine Indicator._ =$1=
This work is designed for the use of erecting and operating engineers,
superintendents and students of steam engineering, relating, as it
does, to the economical use of steam.
The work is profusely illustrated with working cards taken from every
day use, and gives many plain and valuable lessons derived from the
diagrams.
_Guarantee._
_These books we guarantee to be in every way as represented, and if not
found satisfactory can be returned promptly and the amount paid will be
willingly refunded. All books shipped post paid._
_Remittances are best sent by Check, Post Office or Express Money
Orders._
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