Combined Gas and Compressed Air Motors.
Year: 1890

page_text: Date of Application, 8th May, 1890
Complete Specification Left, 6th Feb., 1891-Accepted, 7th Mar.. 1891
Combined Gas and Compressed Air Motors.
A communication from abroad by Doctor RUDOLF PROELL, of 4 Schnorrstrasse,
Dresden, Saxony, German Empire, Civil Engineer, the firm of O. L. KUMMER
& Co., of Niedersedliz, near Dresden, aforesaid, Manufacturers, and EIL.
FISCHINGER, of Niederselliz, near Dresden, aforesaid, Electrician.
I, JOHN CLAYTON MEWBURN, of 55 and 56, Chancery Lane, in the County of
Middlesex, Fellow of the Institute of Patent Agents, do hereby declare the nature
of this invention to be as follows:-
Motors which are driven by compressed air show as regards variations or
alterations in temperature just the opposite of motors driven by gas.
In gas motors in consequence of the gas explosions which take place in the
cylinder of said motors a great amount of heat of combustion is produced which has
to be counteracted by a powerful cooling of the cylinder. On the other hand a
large amount of cold air is produced in motors worked by compressed air if the
latter work with high expansion and the production of cold has to be counteracted
by heating the compressed air before expansion.
By combining two such motors, that is to say a gas motor and a compressed air
motor into one and by suitably conducting the compressed air and employing the
heat of combustion of the gas motor the greatest part of such heat which is lost in
gas motors as hitherto used may be usefully employed for the working of the
compressed air motor.
One manner in which the combined motor can be constructed is to place the
cylinder of the compressed air motor and the cylinder of the gas motor tandem
fashion, their pistons being on the same rod or moving in unison.
The compressed air in the first instance enters a jacket around the gas motor
cylinder and is heated therein by the heat of combustion in the cylinder, cooling
down the latter simultaneously, and the compressed air thus heated is then
conducted to the valve box of the compressed air motor, from which it is distributed
into the cylinder so as to work by expansion.
If the piston is moving in the direction away from the gas cylinder and the
compressed air while expanding cools down considerably, there will be a trans-
mission of heat from the hot piston of the gas cylinder to the expanding air whereby
an additional transmission or conversion of heat into work will take place, the gas
piston at the same time being cooled correspondingly.
In the meantime the exhaust valve of the gas cylinder having been opened the
same allows the products of explosion to rush to the compressed air cylinder
whereby heat is transmitted to the compressed air during expansion on the other
side of the piston in the air cylinder.
On account of the compensation or balance of the pressure the air on that side
will work according to the difference of area in the surfaces of the pistons.
It is immaterial on account of the considerable masses of metal in which the heat
may be stored, whether the gas engine works on the four time or two time principle.
The working process will in principle suffer no disturbances if at only every second
revolution of the crank an explosion or admission of products of combustion into the
compressed air cylinder takes place.
The construction of the combined motor may be modified in the following
manner: A gas pump driven by the combined motor may compress the gas to the

page_text: pressure of the compressed air. The compressed gas mixes with the compressed
air in a fixed proportion and this mixture is ignited at the beginning of each fresh
stroke of the piston by an electric spark.
In consequence of the initial high pressure of the mixture a higher pressure of
explosion will be created, which in conjunction with the subsequent expansion will
indicate a diagram above or beyond the diagram of the compressed air in the same
manner as the diagram of the high pressure cylinder of a compound engine is above
or beyond the diagram of the low pressure cylinder. The exhaust of the products
of combustion from the gas cylinder into the compressed air cylinder takes place at
higher pressure which assists the working pressure in the compresseal nir cylinder.
The exchange of heat will take place in the same manner as described above,
The heating of compressed air in a heating apparatus or stove before working in
a motor provided for that purpose is an ordinary practice. In systems in which a
considerable power has to be produced by the compressed air motor, such heating
apparatus or stove sometimes require steam boilers which ned special attendance
besides requiring special brickwork and chimney.
The present combination of a gas motor with a compressed air motor effects the
preliminary heating of the compressed air in the combined motor itself, in which
the production of heat automatically takes place, corresponding to the compressed
air required and to the work or power created.
The reciprocal influence of the working fluids upon each other may also take
place in such a manner that the compressed air is heated by the products of
explosion of the gas motor, and the cold of the exhaust compressed air after
expansion is made use of for cooling down the gas motor cylinder. This can le
ffected by means of a vessel arranged in connection with the exhaust valve at
the gas motor through which vessel a tube or a set of tubes or cuiled pipes pass. The
tube or tubes or pipes communicate at one end with the exhaust valve and at the
other end with the jacket of the compressed air motor cylinder, and this jacket
communicates with the atmosphere. The products of explosion therefore heat the
vessel and also the air motor cylinder. Into this vessel the compressed air enters,
and after being sufliciently heated is conducted to the valve los. The exhaust
pipe of the valve box communicates with the jacket of the gas cylinder so that
The cold of the expanded air cool down this cylinder, exhausting then into the
atmosphere.
According to another modification the admission of the compressed air in the
first instance takes place into the jacket of the gas cylinder so as to take up heat
from this cylinder and cool down the latter at the same time and then the com-
pressed air thus heated is conducted to the valve box of the compressed air motor,
the expanded air of the latter escaping into the atmosphere, while the products of
the explosion of the gas motor deliver heat to a vessel'such as that above described
and then to the compressed air cylinder.
In both the modifications above described in which a vessel is provided to be
heated by the products of explosion, a spray of water, may be admitted by a rose or
other similar device; the spray of water becomes evaporated by the heat of the
vessel and the vapors may be conducted together with the compressed air into the
valve box, or the vapors may be conducted separately to the valve box and there
commingle with the compressed air; in both cases the vapor or steam serves as a
carrier of heat for the compressed air.

page_text: COMPLETE SPECIFICATION.
Combined Gas and Compressed Air Motors.
A communication from abroad by Doctor RUDOLF PROELL, of 4 Schnorrstrasse,
Dresden, Saxony, German Empire, Civil Engineer, the firm of O. L. KUMMER
& Co., of Niedersedliz, near Dresden, aforesaid, Manufacturers, and EMIL
FISCHINGER, of Niedersedliz, near Dresden, aforesaid, Electrician.
I, JOHN CLAYTON MEWBURN, of 55 and 56, Chancery Lanc, in the County of
Middlesex, Fellow of the Institute of Patent Agents, 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 :—
In motors, the driving power of which is compressed air, it is necessary to heat
the air before it enters the motor or during expansion because otherwise the air
cannot work expansively and therefore not economically as the temperature of the
expanding air would be reduced to such an extent as to interfere with the proper
working of the engine, or in other words heat must be conveyed into compressed
air engines. In gas or other explosive engines the process is exactly reversed as a
great excess of heat is liberated by the explosions which must be conducted away
by waterjackets or other means.
The present invention consists in combining a compressed air motor and a gas or
explosive motor in such a manner that an exchange of heat takes place between the
two motors viz. that the excess of heat generated by the explosive motor serves to
heat the compressed air while the excess cold created by the compressed air motor
serves to cool the explosive motor.
The accompanying drawings illustrate several ways in which the invention can
be carried out.
In Figure 1, A is the gas or explosive cylinder and B the compressed air
cylinder. The compressed air enters the jacket C of the gas cylinder at atmo-
spheric temperature and takes up heat from the said jacket whereby the compressed
air becomes heated and the gas cylinder is cooled. From the jacket C the
compressed air passes into the valve box and is distributed by a slide or other
valves to the two sides of the piston in the usual manner. When the two pistons
have nearly finished their stroke in the direction of the arrow the valve opens the
front port to the compressed air while the exhaust valve v of the gas cylinder opens
simultaneously and the exhaust gases from this cylinder which are still of a high
temperature pass through the pipe P into the jacket of the compressed air cylinder
as well as into the compressed air cylinder and simultaneously heat the cylinder
itself and also the compressed air with which the gases mix and the mixture is
able to expand without undue reduction in temperature. When the compressed
air is working on the return stroke in the back end of the cylinder heat is
conveyed to it by the hot walls of the gas cylinder as well as by the hot piston and
piston trunk.
In the arrangement of the invention represented in Figure 2 the hot exhaust
gases from the gas cylinder are conducted through a pipe or a system of pipes of
suitable conductive metal and surface (which are represented in the drawing by
the tube E and are enclosed in the receiver or vessel D) into the jacket of the
compressed air cylinder and thence into the atmosphere. The compressed air
passes through the receiver D and thence through the pipe J into the valve box.
After it has done its work in the compressed air cylinder it is exhausted through
the pipe F into the jacket of the gas cylinder which it thus cools.
A third way of carrying the invention into effect is shown in Figure 3 where the
compressed air passes first through the jacket of the gas cylinder and thence into
the valve box of the compressed air cylinder and having done its work in this
cylinder it is exhausted into the atmosphere. The exhaust gases of the explosive

page_text: cylinder pass as in Figure 2 through the pipe or system of pipes E within the
receiver D into the jacket of the compressed air cylinder.
The receiver D is also connerted with the valve box. In the two constructions
illustrated in Figures 2 and 3 a jet or rose K is shown through which water can be
injected into the receiver D. On coming into contact with the surfaces of the pipe
or system of pipes E which are heated by the exhaust gases from the cylinder A
the water is evaporated and the steam will mix with the compressed air to which it
will during expansion transfer the heat which it has absorbed from the exhaust
gases. Instead of the jet or rose being situated in the receiver D as shown it may
be arranged to inject water at any other suitable part where the heat of the exhaust
gases will act upon it and convert it into steam.
Although it is preferred to connect the two motive cylinders in tandem fashion
it is evident that any other suitable arrangement may be chosen.
Inving now particularly described and ascertained the nature of my said inven-
tion, as commiented to me, and in what manner the same is to be performed,
I declare that what 1 claim is :-
1. The combination in a motor of a cylinder the piston of which is actunted by
the ignition of an explosive mixture, another cylinder the piston of which is
actuated by compressed air, and conduits or passages for the compressed air and
the hot exhaust gases, these conduits or passages being so arranged that an
exchange of heat takes place the compressed air being heated by the excess of heat
generated in the explosive cylinder and the explosive cylinder being cooled by the
compressed air, substantially as set forth.
2. The combination with a motor constructed as described in Claim 1 of'n water
jet or rose which injects water into a part of the motor where the heat of the
exhaust gases will act upon it and convert it into steam which steam is then mixed
with the compressed air substantially as set forth.
3. The several arrangements of combined gas and compressed air motors herein-
before described and represented in the accompanying drawings.
Dated this 6th day of February 1891.
AFISA 12 IN