Improvements in and relating to Ammonia-engines and to Apparatus Connected therewith.
Year: 1889

page_text: Improvements in and relating to Ammonia-engines and to Apparatus
Connected therewith.
I, JOSEPH HENDERSON CAMPBELL, of 35 Wall Street, New York, County and State
of New York, United States of America, Engineer, do hereby declare the nature of
this invention for "IMPROVEMENTS IN AND RELATING TO AMMONIA-ENGINES AND TO
APPARATUS CONNECTED THEREWITH" and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :-
My invention relates to ammonia engines, the operation of which is substantially
as follows: Aqua ammonia is placed in a boiler to which heat is applied to liberate the
ammonia gas held in solution by the water. The ammonia gas then passes to and
operates the engine, and the exhaust gas re-saturates partially spent aqua ammonia
(previously drawn from the boiler) before returning it to said boiler. This saturation
is effected by cooling said partially spent aqua amiñonia and bringing it into contact
with the exhaust ammonia gas or vapor, which it absorbs, thus increasing the degree
of saturation of the aqua ammonia, which is then returned to the boiler for repeating
the operation.
To understand my improvement it is necessary to remember that as the ammonia
gas is expelled from the aqua ammonia in the boiler by heat, it is requisite for the
re-absorption of the gas by the water or by weak solution, that the liquid should be
cool, the degree of possible saturation varying with the temperature of the liquid; and
also, that when absorption takes place heat is evolved. In carrying out my present
invention I utilize these necessary conditions to increase the efficiency of my method
and apparatus.
The purposes of my invention are to provide methods and apparatus for accom-
plishing the following objects: 1. To fully saturate the weak solution used for
spraying the exhaust vapor from the cylinder of the engine, by subjecting such
solution, together with the excess or unabsorbed vapor, to progressive and continuous
steps of absorption, and to disseminate the heat of absorption set free at each such step
by means of cooling fluid; 2. To draw off any vapor or gas in excess of saturation of
the spraying fluid, after said fluid has been used for absorbing the exhaust vapor,

page_text: enforcing final absorption by pressure; 3. To lubricate the cylinder and the valves of
the steam chest; 4: To operate, in conjunction with the main engine, a vapor pump
or secondary engine using the same absorbing apparatus as the main engine; 5. To
control or neutralize, automatically or otherwise, any excess of pressure that may
occur in the boiler, without the discharge or waste of any of the, ammonia contained
within it; 6. To prevent any foreign matter such as scale, etc., from passing from the
boiler to a jet used for' spraying or absorbing the exhaust vapor of the engine.
The foregoing and other novel and important features of my invention will be fully
described hereinafter and pointed out in the claims.
In the drawings I have shown, in a longitudinal vertical view, partly in section, an
apparatus embodying the various features of my invention.
A, is a steam boiler of ordinary construction, and provided with a main vapor
valve C. D-is the vapor pipe for supplying the engine cylinder E, from which the
exhaust ammonia vapor is discharged into the exhaust pipe O. C₁, is the throttle
valve for regulating the supply of vapor to said cylinder. J, is a pipe conveying the
absorbing liquid. (which is aqua ammonia partly deprived of its aminonia gas) from
the boiler A, to the exhaust pipe O, of cylinder E, where it discharges the liquid
under "boiler pressure" by means of the jet J. The weak ammonia solution, in
order to make it suitable for absorbing the exhaust vapor, had preferably be reduced
in temperature below that of the liquid in the boiler. This is accomplished by passing
it by the pipe J first through the reservoir H, where it is cooled by imparting heat to
the combined exhaust vapor and absorbing liquid on their way back into the boiler.
From reservoir H, the pipe J, passes then in the form of a coil through another
reservoir T, where the weak solution from the boiler is further reduced to a proper
temperature by cold water from any suitable source, surrounding said coiled pipe J,
and supplied by pipe a, and discharged by pipe a. The pipe J, after leaving the
cooling reservoirs H and T, enters the exhaust pipe O, near the exhaust ports of the
engine, and discharges the cooled weak solution (drawn from boiler A) downward, in
the form of spray, which being under "boiler pressure" creates a strong induced
current through the exhaust pipe O, in the direction away from the cylinder E,
whereby the ammonia vapor, upon being exhausted from cylinder E, is withdrawn by
the induced current created at J¹, and is mixed with the absorbing liquid. By this
*means absorption of a part of the exhaust ammonia vapor takes place, and heat (known,
as heat of absorption) is evolved.
This heat combined with the sensible heat of the exhaust vapor, having a constant
tendency towards defeating further and complete absorption of the exhaust ammonia
vapor, I dispose of, by circulating the liquid and exhaust vapor combined through the
absorbers S and S'. The absorber S, is provided with a series of horizontal tubes n₁₁,
ng n₂ and n₂ n, and with double heads G₁ and G₁, the spaces between said double
heads being divided by means of partitions g₁ and 92; so as to form the chambers 1,
2,3 and 4.
The combined spraying fluid and exhaust vapor passes through the pipe O, into the
horizontal absorber S, and thence through pipe O₁ on its way to the secondary
absorber S¹, which is of a construction similar to that of S, having horizontal tubes
and double heads; the, solution in absorber S¹, however, being made to pass around
the tubes, while the cooling water supplied through pipe a₁, passes through said tubes,
after having circulated through pipes ao a.
Leaving the chambers and tubes of absorber S¹, the cooling water passes through
the pipe a, and around the tubes in absorber S, and is finally discharged through
pipe a. The completion of the absorption of the exhaust vapor in absorbers S and S¹,
is accomplished gradually, as follows:
The liquid and gas together pass from pipe O, and chamber 1, in the absorber S,
through the pipes or tubes n n into the chamber 2, where the liquid drops down to
the bottom of said chamber to the pipes n, n, and absorbs the vapor which has
accumulated in said chamber. By this act of absorption the solution is raised by the
heat of absorption" to a temperature so high that, its capacity for absorbing more
vapor is reduced, and it is therefore returned through the cooling tubes n, no, where

page_text: its temperature is reduced and its capacity for absorption restored, to the chamber 3,
where it again falls through the vapor confined in the chamber and absorbs a further
quantity of vapor.
The heat of absorption again raises the temperature of the solution, but, in passing
through the tubes n, n, it is again cooled, and falling through the vapor in the
chamber 4, it absorbs an additional amount of vapor on its way towards the
absorber S¹, where further saturation takes place. By providing the absorber S with
vertical chambers and horizontal tubes and partitions, the liquid contents of the
absorber are rapidly removed by gravity, leaving the tubes and cooling surfaces
exposed to contact with the exhaust vapor and incoming solution as they pass
successively from one chamber to another, and furthermore, any accumulation of the
exhaust vapor at the entrance or top of the absorber is prevented.
It will be seen that the two absorbers S, and S¹, might be consolidated in one frame
or body, without changing their operation.
The solution after having absorbed a sufficient amount of the vapor, to produce a
partial vacuum in the cylinder, by passing first down through the primary absorber S,
and up through the secondary absorber S¹, finds its way to the air tight reservoir or
well W, through the pipes 0, 0, 0, or through pipe O2, pump P1, and pipes O, and O,.
On account of the velocity with which the solution is carried forward by force of the
induced current created by the spray, as before described, and the vacuum created by
the absorption of the vapor, and the action of pump P', a portion of the ammonia vapor
adheres to the solution in excess of saturation. This excess of vapor is, however,
released, as soon as the solution comes to a state of rest. To avoid back pressure on
the piston, which would result from the vapor which has been carried along by
adhesion being thus released, the solution is caused to enter at the bottom or lower
part of the secondary absorber S¹, and to overflow from the top into the well. W,
which it enters at the bottom, or into pump P1, as the case may be.
As a consequence the absorber S¹, is at all times full of the solution, which is
maintained at a sufficiently low temperature by means of the cooling water passing
through it, so that free vapor released from the incoming solution may be absorbed
therein. P is a pump of any suitable kind capable of pumping either liquid, or
gases, or both simultaneously. It is located between the absorber S¹ and welf W, or
may be placed instead between the absorbers S and S¹. Its office is to increase the
vacuum in the cylinder E of the engine by withdrawing the liquid and any.
free ammonia gas from pipe O, and to produce a pressure in the receiving well;
thus assisting the engine and aiding absorption, as ammonia gas will be more
readily absorbed by water or by a weak solution, when the gas and liquid are under
pressure.
-
The feed pump P takes its liquid from the well W, through pipe O, and forces
such liquid into the boiler through pipe F. The pipe O, may enter the well W, at
about one-half its height, as shown, thus permitting the well to remain partially filled
with the solution, in order that the gases or vapor carried along by adhesion into the
well may be dissolved in this solution; and furthermore, by having the well only
partialty filled with the solution, a space is left in its upper portion for the reception
and separation of any air which may have been drawn into the apparatus. To remove
such air from the well W, it would only be necessary to stop the operation of the feed.
pump P, so as to allow the solution to rise in said well and to thus expel the air by
opening a cock c, closing pipe n on top of the well. The pump P₁ is principally
intended to reduce the amount of cooling water needed where it is difficult to obtain
sufficient quantities of the same; by substituting compression in. well W, for the
additional cooling water which would otherwise be required for the complete
absorption of the ammonia vapor.. When the engine is running with only a partial
load, the power required for running pump P¹ may be saved, by disconnecting it,
and allowing the solution to pass from pipe O, into pipe O, through pipe O; Vis a
check valve constructed to open towards pipe 0, when the pressure in pipe O, equals or
exceeds that, in pipe O. Instead of the check valve V₁ an ordinary cock, to be
operated by hand, might be substituted.

page_text: The feed pump P. receives its supply of vapor from pipe d, connected with pipe D,
and exhausts into pipe d₂, which leads into pipe O at a point x. c, is a cock located
in pipe d₁ for regulating its supply of vapor.
The operation of the pump P, is that of an ordinary steam pump, except that its
exhaust is returned to the boiler by the aid of the spray or absorbing liquid used for
the cylinder of the main engine, it being found in practice difficult to use an
independent spray for the pump without using an orifice or nozzle so large that the
economy of the plant would be materially affected. The amount of vapor required
for the work, to be performed by pump P, being small, it is not necessary to
depend upon an independent spray jet for the absorption of the exhaust vapor,
it being sufficient to bring it in contact with the combined absorbing fluid and
exhaust vapor by introducing it into pipe O at X, before the same enter the
absorbers S and S¹.
Instead of introducing the exhaust of pump P at point X, such connection might
be made with the absorbing apparatus of the main engine at any other suitable point,
so as to utilize for the absorption of the exhaust of pump P, the same liquid which
also serves to absorb the exhaust vapor of the main engine.
In order to relieve the boiler of an excess of pressure, without being obliged to
depend upon an ordinary safety valve opening into the atmosphere, I provide the
pipe M, which leads from the main vapor pipe D, to a point Y, in exhaust pipe O, and
locate within said pipe M an automatic valve V2, adjusted to open when such excessive
pressure is reached, thus conveying the excess of gas directly to the absorbing
apparatus of the engine, where it is absorbed in the same manner as the exhaust vapor
of the engine is disposed of. In place of the automatic valve V₂ a cock might be
used for passing the excess of vapor to the absorbing apparatus.
2
I is a pipe leading from the spray pipe J into the valve chest of engine cylinder E.
In order to obtain proper lubrication of the valve chest and engine cylinder,
particularly before starting the engine, I inject into the same weak solution. The
cock ca serves to regulate the supply of such liquid which thus is employed as a
lubricant.:
As it may happen, when ammonia is first introduced into the boiler, that impurities,
such as scale, be taken up by the spraying fluid, it is desirable to prevent such
impurities, from reaching and obstructing the small nozzle J¹, and for such purpose
I provide in J the casing U, with strainer Z, in such a manner that the strainer
may be taken out and cleaned. For such purpose I form the lower part of casing U
as a detachable pocket, in which impurities may be temporarily received.
The cock will serve to shut off the liquid while casing Ŭ and the strainer Z
within it, are being cleaned. It may also be used to regulate the amount of absorbing
liquid which it is desired to pass through said pipe J.
Having now particularly described and ascertained the nature of said inven-
tion, and, in what manner the same is to be performed, I declare that what I
claim is:
1
1. In ammonia engines, the method herein described of absorbing the exhaust
ammonia vapor, which consists in bringing said vapor in contact with partially
spent aqua ammonia (a solution) drawn from the boiler, and then subjecting such
solution in presence of unabsorbed vapor to successive absorptions simultaneous with
coolings taking place within a series of lateral tubes in a horizontal absorber,
aiding each such absorption by removing the access of sensible heat generated
thereby, substantially as and for the purpose described.
2. In ammonia, engines, the method herein described of aiding absorption of the
exhaust vapor, which consists in interposing between the inlet of a horizontal
absorber, drained by gravity, and the feed pump, a body of absorbing liquid,
through, which any free gas must pass before reaching the feed pump, substantially
as set forth.).
In ammonia engines, the method herein described of absorbing exhaust
ammonia vapor from the engine, which consists in bringing such vapor in contact

page_text: with a continuous stream of cooled, partially spent ammonia solution from the
boiler, then subjecting such solution and unabsorbed vapor to successive absorp-
tions and coolings after each absorption, in a horizontal absorber, to remove the
access of sensible heat produced thereby, draining the solution from such absorber
by gravity, into a partially filled close vessel or well, entering the same below the
surface of ammonia solution contained therein, substantially as and for the purpose
described.
4. In ammonia engines, the method herein described of absorbing vapor of
ammonia, which consists in passing the same together with cooled and partially
spent ammonia solution from the boiler into the upper part of a horizontal
absorber, draining therefrom, by gravity, such solution and absorbed gas and free
gas adhering to such solution, through lateral tubes and vertical chambers, sub-
stantially as described.
5. The method herein described of operating an aqua ammonia engine, which
consists in propelling the engine with vapor of ammonia expelled from aqua
ammonia in a boiler by heat, bringing the exhaust vapor in contact with cooled,
partially spent ammonia solution from the boiler, subjecting such solution together
with unabsorbed exhaust vapor to successive absorptions, simultaneous with coolings,
taking place within a series of lateral tubes in a horizontal absorber, alternating
with the evolutions of heat generated by absorption in vertical chambers, and
returning the liquid which has absorbed the exhaust ammonia vapor to the boiler,
substantially as described.
•
6. The method herein described of operating an aqua ammonia engine, consisting
in expelling ammonia vapor by heat from aqua ammonia in a boiler, propelling the
engine with such vapor, passing the exhaust ammonia vapor together with cooled,
partially spent ammonia solution withdrawn from the boiler into the upper part of a
horizontal absorber, provided with lateral tubes, so as to drain the liquid therefrom
by gravity into a secondary absorber, provided with cooling surfaces, entering it
below the surface of a body of ammonia solution contained therein, and returning
the contents of such secondary absorber to the boiler, substantially as set forth.
7. The method herein described of operating an aqua ammonia engine, consisting
in expelling ammonia vapor by heat from aqua ammonia in a boiler, propelling the
engine with ammonia vapor, passing the exhaust vapor together with partially spent
ammonia solution from the boiler into the upper part of a horizontal absorber, pro-
vided with lateral tubes and vertical chambers so as to drain the liquid therefrom
by gravity into a secondary absorber provided with cooling surfaces, entering it
below the surface of a body of ammonia solution contained therein, then passing
such liquid into a well from which it is returned to the boiler, substantially as set
forth.
8. In ammonia engines, the method herein described of increasing the efficiency of
the engine, which consists in removing the exhaust from the cylinder by bringing
the same in contact with absorbing liquid, and forcing the two combined into a
closed well, by means of a suction and force pump, situate and operating between
an absorbing apparatus and the well, substantially as described.
9. The method herein described of operating a vapor pump or secondary engine
in combination with an aqua ammonia engine, the same consisting in driving such
pump or secondary engine directly by vapor of aqua ammonia and absorbing the
exhaust vapor of said pump or secondary engine by the absorbing liquid which
serves also to absorb the exhaust of the principal engine, substantially as set
forth.
10. The method herein described of relieving the boiler of an aqua ammonia engine
of an excess of pressure, which consists in transferring the vapor from the boiler
directly to the absorbers and well, without passing it through the engine, and
bringing said vapor in contact with a continuous stream, under "boiler pressure,'
of the cooled weak solution, or fluid, while in transit to the absorbers, as set
forth.
"

page_text: 11. In an aqua ammonia engine, the method herein described of preventing
scale or other foreign matter from passing from the boiler to the absorbing jet,
which consists in interposing in the pipe connecting the same a suitable strainer
substantially as set forth.
12. The method herein described of lubricating the cylinder of an aqua ammonia
engine, by injecting into its valve chest aqua ammonia under boiler pressure and
withdrawn from the boiler.
13. In an aqua ammonia engine, the combinatian with the boiler of a spray
jet and absorbers for absorbing the exhaust vapor, an air pump, receiving well
and a feed pump, said well being placed between said pumps, substantially as set
forth.
14. In an engine of the character described, the combination with an apparatus
for reabsorbing the exhaust vapor, the pump P1 placed between the absorbers and
the well W, and a by-pass around said pump, with suitable valve, substantially as
set forth.
15. In an engine of the character described, the combination with the boiler and the
spray pipe J, of the casing U, with detachable bottom and containing the strainer Z,
substantially as set forth.
16. In an engine of the character described, the combination with the boiler
and the spray pipe of the strainer Z, and cock C,, substantially as specified.
JOSEPH HENDERSON CAMPBELL.
Haseltine, Lake & Co..
45, Southampton Buildings, London,
Agents for the Applicant.