Improvements in or relating to Gas and similar Motors.
Year: 1894

page_text: Date of Application, 7th Aug., 1894-Accepted, 22nd Sept., 1894
COMPLETE SPECIFICATION.
Improvements in or relating to Gas and similar Motors.
I, GEORGE SCHIMMING, Engineer, of Martinickenfelde near Berlin, in the
Empire of Germany, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement :-
This invention relates to improvements to be effected in the conversion of heat in
gas motors, by means of a special method of water-injection in the working
cylinder, and of expanding the motive agent generated in the working cylinder.
The loss of power in gas-engines is chiefly two-fold; 1. Owing to the lowering
of temperature by cooling with water; from 27.1 per cent. to 47-1 per cent. of the
available caloric is wasted in gas-engines as now constructed, and 2. Owing to the
fact that the exhaust gases escaping from the motor have a temperature of from
600 to 800 degrees C., 37-9 to 42.3 per cent. of the available caloric is wasted.
The loss of power specified above in 1. may be reduced by a water-injection
arranged to take place in the exploded mixture during the working stroke, and
thereby characterised
a) That the water-injection does not take place during the combustion, in order
that the gases, during combustion, may not be lowered in temperature below the
point of ignition, which would cause the combustion to be incomplete and result in
an unfavorable working of the engine,
b) That the water-injection is not too weak, so as to be ineffective and render
necessary a further external cooling with cold water, nor yet too strong, which
would reduce the temperature of the gases during the working stroke ;-that is to
say, the water-injection must cease, so soon as the gases and combustion-products,
during the working stroke, have attained that exact degree of tension (or expansion) at
which, having regard to the durability and maintenance of the working parts, the
highest admissible temperature of the gases is obtained.
That degree of tension or expansion may be experimentally determined for each
motor and each kind of gas, or vapour individually.
The nature and manner of this particular water-injection, during the working
stroke, into the exploded mixture may be shown by the graphic method, as in the
indicator-diagram of a gas-motor (Figure 1), wherein the water-injection after the
explosive combustion commences at A and terminates at B, approximately, at
which latter point the gases are so far cooled down that further external cooling
is unnecessary whereby consequently such further cooling is avoided. By such
water-injection, the first-named loss, which is caused by the cold water, is thereby
avoided so that the heat which would otherwise escape outwards, is utilised in
the working cylinder for the generation of vapour, and the vapour thus generated,
while increasing the tension with the other gases and vapours generated by the
combustion, is expanded in common with the latter, doing useful work.
In order to effect the water-injection, in the manner and with the effect described
two processes or methods are shown under this invention.
The first process is best explained and made intelligible by reference to
Figures 2, 3 and 4 of the accompanying drawings.
In Figure 2 the chamber or space 1 is in open communication with the working
cylinder, so that the pressure in the latter acts directly on the differential
piston 2-3, from below (2) upwards. From the top, the upper portion of the
differential piston (3) is loaded by the water 4 under pressure which, in the position
of the piston as represented in the drawing, can find no outlet or vent into the
chamber 1, because the piston 5, by means of the valve rod 6, draws the valve 7

page_text: tightly upwards against its seat. Even when the explosion takes place, at which
time indeed the pressure, as shown in the indicator-diagram (Figure 1), mounts
suddenly from C to D, no water-injection takes place, for, so soon as the piston 2-3
is forced up to the position shown in dotted lines at n (Figure 2) 5, 6 and 7 are
thrown up at the same moment with it; while, at the same time, 1st, the gas-
pressure acts from below on the valve 7, and 2ndly, the water-pressure acts upon the
piston 5, the cross section whereof exceeds that of valve 7. In consequence of the
explosion the roller 8 of the piston 5 is thrust up to N*. So soon as the explosion
has taken place and the point A in the diagram Figure 1 has been reached, the
cam-enlargement or projection 9 of the disc 10, which is operated by the
distributing or valve-motion shaft 11, presses the valve 7 downwards. If
the upward displacement of the piston 2 amounts to 10 m.m., then the depression
of the valve 7 by the cam 9 is 5 m.m., and the water injection begins. The cam 9
will now keep the valve 7 open during the greater part of the stroke; but so soon
as the pressure (as shown in the diagram Figure 1) sinks below that at which, as
experimentally determined, the above-indicated temperature of the gases and
vapours is attained, by decrease in expansion (¿.e. the temperature at which further
external cooling of the gases etc. by water is unnecessary and the gases are not
wastefully cooled) the water-pressure 4 depresses the differential piston 2-3 to the
extent of 10 m.m. The valve 7 having been opened to the extent of 5 m.m. by
the cam 9, it follows that, so soon as the piston 2-3 has receded 5 m.m., it closes
the valve 7, and, by means of the valve-rod 6, draws the upper piston 5 back to its
former position. Consequently, the appropriate injection of water, between the
points A and B in diagram Figure 1, has thus been brought about, by the opening
of the valve 7, at the point A, by means of the distributing device 11, 10, 9,
operated by the motor, and thus cut off, at the point B, by a loaded piston, actuated
by the pressure in the working-cylinder.
In one case, the distributing or valve motion shaft 11 may be firmly attached to
the cam or projection 9, or in another replaced by a fixed adjustable stop or striker.
Whenever the supply-pipe 12 for the water 4 under pressure is so contracted that
the upward movement of the differential piston 2-3 (at which time the supply-
pipe acts as an outlet pipe) during the explosion is thereby hindered or delayed,
the adjustable tappet or striker 13 (Figure 3) is used, in substitution for the disc 10
and cam or projection shoulder 9. Then, in this case, the stop-device 13 effects the
opening of the valve 7 in a similar manner, after the completed combustion has
brought the pressure to the point A (Figure 1). In all other respects the
construction and working of the apparatus remains unchanged in both the supposed
cases.
Herein, the space
The apparatus shown in Figure 4 acts in the same manner.
or chamber 14, below the piston 15, is in open communication with the working
cylinder. The piston 15, by means of its rod 16 is loaded by the spring 17, and
the lever and rod combination 19, 20, 21, actuated by the fixed collar 18 of the
piston rod 16, communicates the movement of the latter to the rocking arm 22,
which is jointed at its lower end to the auxiliary valve-piston 23, and, at its upper
end, carries the roller 24. The piston 23, by reason of the proportions of its cross-
sectional area to that of the valve 25, with which it is connected by its piston-rod 26,
is forced upwards so as to keep the valve normally closed. The explosion in the
working cylinder, by its pressure, transmitted to the chamber 14, forces the
piston 15 and consequently the rocking arm 22 into the position shown in Figure 4.
So soon, however, as the pressure declines to the point A Figure 1, the projection
or cam 9 of the disc 10, mounted on the distributing or valve motion shaft 11,
depresses the armı 22 and with it the piston 23 and valve 25; whereupon the water-
injection commences, then, as soon as the pressure under the piston 15 falls, i.e.,
when the pressure in the working-cylinder declines to the point B (Figure 1)
the piston 15 is pressed downwards by the spring, and, by means of the
connections 19, 20, 21, the rocking arm 22 is drawn to the right so that the roller 24
is no longer in the path of the projection or cam 9. Thereupon the water pressure

page_text: at 27 raises the piston 23 to its normal position, closing Lue valve 20 and cutting on
the water-injection.
The principle of this first arrangement, for the injection of water during the
working-stroke of a gas-motor into the exploded mixture in the working cylinder,
may therefore be set forth as characterised by a water-injector which is actuated in
one case by means of a distributive mechanism, operated directly by the motor (or
in the other case by means of an adjustable stop or striker) so soon as the ignition
and combustion of the explosive mixture in the motor has taken place; which
mechanism (or injection-regulator) is closed, so soon as the pressure in the cylinder
has fallen below a predetermined minimum, by the displacement of a piston
subjected on the one side to the pressure prevailing in the working cylinder & on
the other side to pressure exerted by water, air, or a spring.
This arrangement has the great advantage that the water-injection, under
appropriate conditions of pressure, invariably takes place in proper quantity and
over a suitable period of time; as also that the charge of gas at each stroke may
be regulated at will.
The second method, hereinafter described, has this advantage, however, that, in
point of construction, it can be carried out by the use of very simple means.
If the pivot or gudgeons of the roller 24 (Figure 4) is or are connected with the
style of an indicator, while the chart carrying cylinder of such indicator is rotated
The
by the motor in the usual way, the result is shown in the diagram Figure 5.
piston-stroke of the engine commences at E, and F indicates the end of the
explosion; at G the distribution device opens the valve 25 by the depression of
the roller 24 (Figure 4) whereby the water-injection is begun; at H the injector
is automatically closed by the fall in the pressure of the working cylinder; and
K is the end of the stroke. Consequently, for the stroke E. K, the line G H
represents the water-injection both as to time and duration. If a stronger gas-
charge be chosen, the water-injection may last a little longer, as e.g. from G to H'.
If the same thing be done with the gas-admission device, i.e. if the valve-spindle
be connected with the indicator style, while the chart cylinder is rotated by the
engine in the customary manner, then we obtain for the gas-charge which induced
the water-injection represented by the line G-E (Fig. 5) the charge-volume L M
(Fig. 6), where NP represents the length of the stroke. As, in Fig. 5, the water-
injection from G to E was automatically induced, so Fig. 6 gives the corresponding
gas-charge L M. Therefore every gas-charge L M as shown by the indicator-
style on the diagram, corresponds with a different automatically-determined water-
injection GH, obtained by the aid of the apparatus (Fig. 2 or Fig. 4).
If then in connection with a gas-engine arranged for water-injection during the
stroke, an apparatus is applied which regulates the water-injection automatically,
in conformity with the above-described method, and if at the same time, indicator-
diagrams are taken as mentioned of the gas supply valve and water injector, the
law would be determined which governs the change in the water injection in
relation to a change in the gas-charge, and thus we are enabled to arrange a
suitably adapted apparatus in substitution for that represented in Fig. 2 with a
water-supply or injection-valve which can be adjusted by screwing up or unscrewing,
so as to be automatically actuated and regulated, to correspond to the gas-
consumption, by the distributing mechanism of the machine, conformably to the
law so found for it.
There are other methods besides that above described, of determining
experimentally in each case the proper and exact quantity of water to be injected,
in such manner that no further external cooling may be required or effected, and so
would be
an excessive water-injection may be avoided. These, however,
superfluous to specify here because the determination of the law which governs
the quantity of water injected in proportion to the gas-consumption, as above set.
forth is not the subject of this Patent Application.
Fig. 7 illustrates a distributing device which so regulates the water-injection
according to the gas-consumption. The shaft 28 driven by the motor drives by

page_text: means of spur or equivalent gear the governor 29, and also by bevel-gear the
distribution shaft 30. Mounted on the latter is the valve-motion or cam disc 31,
for actuating the gas-supply valve; as also the cam 32 for the air-supply valve
and the cam-disc 33 for the water-injection device. The cam-discs 31 and 33 are
simultaneously caused to slide longitudinally on the shaft 30 by the regulating
lever system of the governor 29. The acting outlines of 31 and 33 are formed in
similar and corresponding spirals in such manner that, in accordance with the
explanations just given, they are so proportioned one to the other, that when 31 is
set for any particular gas supply, 33 is set to the water-injection corresponding
thereto. The water-supply valve consists of a piston 35 which under water-
pressure loads the valve 36 and keeps it pressed upwards against the valve-seat
and through which the valve is relieved; 37 indicates the working cylinder of the
gas-engine, 38 its piston, and 39 the eduction valve or slide.
In the larger class of gas-motors a hydraulic relay is introduced between the
governor 29 and the cam-shaft 30.
In gas-motors working with a fixed and constant charge, and wherein the
regulation is effected by the escape of the charges, a simple cam takes the place of
the cam disc 31 with spiral outline and to correspond therewith the cam-disc 33
for the water-injection is also replaced by a simple cam of corresponding form.
The working with an invariable charge is only a particular case of the previously
described arrangement. in general.
The second method of injecting water into the working-cylinder during the
working stroke consists in the arrangement of an admission device for the water
to be injected, so actuated by the distribution mechanism driven by the motor that
the water-injection commences at the completion of the explosion and combustion
of the charge, and its duration is determined by the gas-charge admitted at each
stroke, while at the same time the cut-off is so adjusted thereby that no further
external cooling by cold water is necessary and thus the highest admissible
temperature of the gases and combustion products is attained, consistently with the
durability and maintenance of the working parts, without any further external
application of cold water to cool the cylinder.
The above-described methods and apparatus for the injection of water during
each working stroke, in gas-motors, are equally applicable to gas-motors in which
the gas-charge is admitted at every alternate stroke, or once in a quadruple cycle;
as well as in motors which are operated by the explosive combustion of gases,
vapours or finely comminuted substances.
The second mode of.economising heat and improving its utilisation in gas-engines
consists in the gases and combustion products, which by an appropriate process of
water-injection during the working stroke are maintained in the exploded condition
being allowed to expand exactly as in compounded steam engines, with double-triple
or quadruple expansion cylinders, and the vapours and gases are condensed and
cooled in a special condenser. In this manner the loss previously mentioned due
to the high temperature of the exhaust gases, is diminished.
In all existing gas-engines the fall of temperature actually utilised is from about
.2000° C. to 800° C. or 600° C.; whereas by the expansion of the gases and com-
bustion products generated through the water-injection during the working-stroke
in the exploded mixture, by means of this invention the fall of temperature which
is available for useful work is from about 2000° C. to about 40° C.
In gas-engines working with a quadruple cycle, the compound cylinders are
arranged as shown in Figure 8.
In the cylinder 40 moves the piston 41 which is connected by the common piston-
rod 42 to the piston 43 of the cylinder 44. The piston rod in the latter (44)
communicates the movement of piston 43 to the driving gear of the engine. The
cylinders are fitted with the sto-cocks 45, 46, 47 and adjacent to them is the
condenser 48. The gaseous condensation products escape from 48 by the exhaust
pipe 49 and the fluid products through the eduction pipe 50. The water-injection
takes place through 51. The piston 41 in the cylinder 40 draws in air and gas

page_text: mixture at the first (down) stroke and compresses the same at the second or return-
stroke. During the third stroke after the ignition and explosion of the explosive
mixture, and the subsequent injection of water as described, or in any convenient
and suitable manner, a motive agent is generated, consisting of highly-heated gases
and superheated steam which (during such third stroke) drives the united pistons
downwards. During the fourth stroke, the escape and admission valves 45 and 46
are opened, the admixture of gas and steam passes, through the connecting pipe 52,
from 40 into 44, and is expanded with useful effect. This completes the quadruple
cycle of four strokes and at the next stroke the ensuing cycle commences. During
the first stroke of the next cycle the escape and admission valves 45 and 46 are
closed and the outlet valve 47 is opened, the piston 43 forces the expanded mixture
of gas and steam through the outlet pipe 53 and loaded or non-return valve 54 into
the condenser 48. At the same time (ie. during the first stroke of the new cycle)
the piston 41 renews the working of the cycle by drawing in a fresh supply of gas
and air. Meanwhile, in the condenser 48, the exhaust gases and steam are dealt
with by the injection of water, which condenses the steam and thus creates a partial
vacuum. In consequence of the descent of the piston 43 the pressure increases
subsequently in the condenser until atmospheric pressure is attained; then the non-
return valve 55 opens and allows the gases to escape through 49 while the con-
densed water passes away from the bottom of the condenser through the eduction
pipe 50 and an intermediate non-return valve there provided.
In particular cases an air-pump may be used to empty the condenser as in steam
engines.
The space between the pistons 41 and 43 is not used and may be left freely open
so that the air may enter and leave without in any way affecting the working of the
engine; but it may be closed if preferred so that the air-cushions may facilitate
the action of the motor. Inasmuch however as this intermediate space between the
pistons is of comparatively little or no account in the working of the engine its
form and dimensions may be varied in any desired manner to suit any particular case
e.g. the larger cylinder may be arranged on one side of the smaller, without
influencing the working and useful effect of the gas-engine.
During the fourth and first strokes of the piston in the smaller cylinder, the
piston in the larger cylinder makes idle strokes.
The second stage of expansion in this motor can be subdivided as in steam
engines, so as to give triple or quadruple expansion. Such a subdivision of the
second stage is diagrammatically illustrated in Figure 9. The cylinders 60 and 62
with their pistons 61 and 63 show the arrangement already described, only that
between the larger cylinder 62 and the condenser 64, a third still larger single-
acting cylinder, with two idle strokes of its piston 66, is interposed.
Further also the motor illustrated in Figure 8 can be duplicated or worked in
combination with other like motors, in very various ways. If for instance it be
used as twin-engines it will be advantageous to arrange the two smaller cylinders
to work alternately with a single large cylinder. In this arrangement the com-
bination would be such that the two idle strokes of the one smaller (or high
pressure) cylinder should not be synchronous with those of the other, so that the
larger cylinder is always double-acting. Thence results the combination shown in
Fig. 10. In the cylinders 70 and 72 the pistons 71 and 73 respectively work in
quadruple cycles but alternating; the water-injection in cach cylinder taking place
at the third stroke, as previously set forth in the single larger cylinder however
being common to both, the alternate piston-strokes which are idle for No. 1 motor (70)
are simultaneously working strokes for No. 2 motor (72) and vice versa the idle
strokes in relation to 72 are simultaneously working strokes in relation to 70.
A third combination is illustrated in Figure 11, composed of Figures 9 and 10
combined. Here there are four compound condensing gas-engines, arranged side
by side as follows;
-
The engines 80 and 81 work with alternating piston-strokes, relatively to each

page_text: other as described in relation to Figure 10; both their pistons make their down-
strokes synchronously while simultaneously the piston of the other pair of similar
twin-engines, similarly arranged make their upstrokes together. Thus the four
engines constitute a twin pair of twin engines (Figure 10). Combined therewith,
there are further and located under the outer upper or high pressure cylinders 80
and 83 two corresponding and like low-pressure cylinders 84 and 87 such as shown
in Figure 9, receiving and further expanding the exhaust gases and steam from 86
and 85 respectively and discharging their exhaust into the condensers 88 and 89,
their work being then done. Under this arrangement the course of the working
gases etc. is as shown by the arrows in Fig. 11, i.e. from 80 and 81 in alternation
to 85, from 85 to 87, and thence into the condenser 89, from 82 and 83 in
alternation to 86 from 86 to 84, and thence into the condenser 88. The four com-
pound condensing gas-engines are thus arranged in such manner that the idle piston
strokes in each cylinder of a pair are supplemented and compensated for by those
of the other cylinder, and the large or low-pressure cylinders serve each as a triple
expansion cylinder to one pair of engines.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is ;-
1. In motors driven by the explosion of combustible matter the injection of
water during the working stroke.
2. In motors driven by the explosive combustion of gases vapours or finely
comminuted matter the method of injecting water under pressure into the exploded
mixture during the working stroke in such manner that the admission device for
the water-injection is opened by means of a distributive mechanism actuated by the
motor itself or by an adjustable stop so soon as the combustion of the explosive
mixture in the motor has taken place and that such admission device for the water-
injection is closed by the displacement of a piston loaded on one side by the
pressure of compressed water or air or of a spring and on the other side by the
pressure prevailing in the working cylinder such closure being effected so soon as
the pressure in the working cylinder has after the explosion declined to the point
at which the temperature of the mixture of gas and steam is the highest admissible
consistently with the durability and maintenance of the working parts without
further external cooling by water substantially as described.
3. As a form of development for the application and use of the method or
process described in Claim 2 and apparatus characterised by the combination of
the following devices as illustrated in the accompanying drawings Figures 2
and 3
a) A differential piston such as 2-3 whereof the larger piston head 2 is acted
on by the pressure prevailing in the working cylinder of the explosion motor
while its smaller piston-head 3 is loaded by water pressure 4 in such manner
that a movement of the differential piston takes place whenever a variable
pressure prevails over a constant pressure and in the opposite case a return
or contrary movement is brought about (Figure 2);
b) A valve such as 7 for the water injection moving simultaneously with the
differential piston 2-3 by means of a spring or of a loaded piston 5 and
also kept closed during the movement of the said differential piston
(Figure 2);
c) A distributive mechanism such as 9 10 11 actuated by the motor itself and
whereby the water-injection valve 7 is opened so soon as the roller 8 con-
nected with the water-injection valve 7 when driven upwards together with
the differential piston by the force of the explosion in the working cylinder
has attained a predetermined height substantially as described.
4. The apparatus described in Claim 2 with the modification that instead of the
distribution mechanism described in sub-section e of Claim 3 an adjustable stop 13

page_text: (Figure 3) in combination with a device for contracting the return outlet of the
pressure water (e.g. a perforated valve) is employed substantially as described.
5. As another form of development for the method or process described in
Claim 2 an apparatus characterised by the combination of the following devices as
shown in Figure 4 of the accompanying drawings ;-
-
a) A piston 15 loaded by a spring 17 and moved by the varying pressure
underneath it in the working cylinder;
b) A cut-off valve 25 for the water injection closed automatically by the
water-pressure 27;
c) A distributive mechanism 9 10 11 actuated by the motor itself for opening
the water-injection valve 25 after the explosive combustion of the gases in
the working cylinder;
d) A rod and lever combination such as 19 20 21 22 operating in such manner
that after the lifting of the piston 15 loaded by the spring 17 the distributive
mechanism 9 10 11 is enabled to effect the opening of the cut-off valve 25
for the water-injection substantially as described.
6. In motors driven by the explosive combustion of gases vapours or finely
comminuted matter and in which during the working stroke water is injected into
the exploded mixture in the working cylinder the method or process of operating
the adinission device for water injection by means of a distribution device actuated
by the motor itself in such manner that the water-injection commences after the
explosive combustion of the gases is completed and is determined in relation to the
volume of the gas-charge while at the same time the interdependence between
the consumption of the combustible and the quantity of water injected is so assigned
and proportioned that in all cases no further external cooling with cold water is
necessary and that the highest admissible temperature consistently with the
durability and maintenance of the working parts is attained without such further
external cooling of the cylinder substantially as described.
7. As another form of development for the method or process described in
Claim a distributive mechanism such as shown in Figure 7 consisting in a
combination of two sliding cam discs 31 and 33 whereof the one 31 operates the
gas-admission valve and the other 33 the water-admission valve so constructed and
arranged in connection with each other than when the former 31 is set for the
corresponding proportionate water-injection as experimentally predetermined
substantially as described.
8. In motors driven by the explosive combustion of gases vapours or finely
comminuted matter and in which during the working stroke water is injected into
the exploded mixture in the working cylinder the method or process whereby the
gases and steam generated by such water-injection are expanded in compound
triple or quadruple cylinders in the same manner as practised with the steam of
steam engines substantially as described.
9. As another form of development for the method or process described in
Claim 8 a condensing compound gas engine such as shown in Figure 8 thereby
characterised by the pistons of the smaller or high pressure cylinders working in
quadruple cycle in such manner that at the third working stroke water is injected
into the exploded mixture while after the idle expenditure of the second and third
strokes of the large piston at the fourth stroke a communication is opened from the
small to the large working cylinder in order that the gases may be further expanded
in the latter and at the next following stroke escape into the condenser substantially
as described.
10. The construction and combination of two motors such as described in Claim 9
so as to constitute a condensing triple expansion motor such as shown in Figure 9
and the combination of the condensing compound gas-motor such as described in
Claim 9 and shown in Figure 8 with the condensing triple expansion gas-motor
such as described above in this claim and shown in Figure 9 in such manner that
for each pair of quadruple cycle cylinder only one compound cylinder is provided
as shown in Figure 10 and that two such large cylinders act as triple-expansion

page_text: cylinder for four combined condensing compound gas-motors such as described in
Claim 8 substantially as described and illustrated in Figure 11.
Dated this 7th day of August 1894
W. P. THOMPSON & BOULT,
Agents for the Applicant.