IMPROVEMENTS IN GAS-MOTORS AND PRODUCERS
Year: 1881

page_text: LETTERS PATENT to Charles William Siemens, of No. 12, Queen Anne's Gato,
Westminster, in the County of Middlesex, for an Invention of "IMPROVEMENTS
IN GAS-MOTORS AND PRODUCERS."
PROVISIONAL SPECIFICATION left by the said Charles William Siomens at
the Office of the Commissioners of Patents on the 9th June 1881.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
County of Middlesex. "IMPROVEMENTS IN GAS MOTORS AND PRODUCERS."
In the Specification of a Patent granted to me on the 28th August 1860,
No. 2074, and in a Provisional Specification filed by me on the 28th July 1862,
No. 2143, I described apparatus for the production of inflammable gas and for
applying the combustion thereof for producing motive power. My present Invention
relates to apparatus of that kind, the object of my improvements being to simplify
the construction and operation of the apparatus, and to utilise more fully the heat
developed by the combustion of the fuel employed.
I will first describe the engine in which I apply the combustion of gas to produce
motive power, premising that any inflammable gas may be employed in this engine;
but, as I will hereafter explain, I prefer to combine with the engine a gas producer
so as to form a complete combined apparatus for the production and utilisation of
the inflammable gas.
The engine which I am about to describe may have two or more working
cylinders, and these may be single acting or double acting. In order to simplify
description I will assume that it has one single acting cylinder placed with its axis
vertical. This cylinder consists of two parts, an upper hot part which may be
lined with plumbago or other refractory material, and a lower part which is kept
cool by a water casing. This cylinder is fitted with a trunk piston which works in
the lower part of the cylinder, and has on its upper side a shield that almost fills
the bot part of the cylinder when the piston is at the extreme of its upstroke.
The trunk rod of the piston passes through a stuffing box in the cylinder bottom
and is connected to a crank on the engine shaft, which, unless multiple cylinders

page_text: are employed, carries a heavy flywheel. From the lower end of the cylinder there
is a passage which, by means of a rotating or a reciprocating slide, is alternately put
in communication with inlets for gas and air regulated by suitable cocks or valves,
and with a strong receptacle. As the piston makes its upstroke air and gas are
drawn into the annular space surrounding its trunk, and the mixed air and gas
are compressed by the downstroke of the piston and delivered into the receptacle
in which a considerable pressure is maintained. The receptacle is conveniently
made of cylindrical form with a domed cover of thin sheet metal, which, in case
of excess of internal pressure, can give way, operating as a safety valve to save the
body of the receptacle from damage. From the upper end of the cylinder there is
a passage that, by means of a rotating or reciprocating slide, is alternately put in
communication with the receptacle and with a discharge outlet.
In this passage
are fixed a number of wire gauze screens or pieces of metal with interstices which
constitute a regenerator of heat, and also prevent communication of flame from the
cylinder to the receptacle. In the upper end of the cylinder or of the piston shield
are provided electrodes which give an electric spark from an inductor to ignite the
combustible charge in the cylinder. Instead of such electrodes, there may be in
the cylinder or in the piston shield a mass of spongy platinum or a highly heated
body to cause ignition. After the engine has been for some time at work the heat
at the upper part of the cylinder may suffice for effecting ignition without provision
of other means for that purpose.
The receptacle being charged with compressed mixture of gas and air, the
operation of the engine is as follows:-
As the piston begins to descend the compressed gaseous mixture entering the
upper end of the cylinder heated in its passage through the regenerator is ignited
within the cylinder, and thus has its volume largely expanded whilst its pressure
remains the same as that of the fluid in the receptacle. When the piston has
performed part of its downstroke, the supply of gaseous mixture is cut off by the
slide and the heated contents of the cylinder expand, propelling the piston. When
the piston has completed its downstroke the exhaust passage is opened by the
slide and the expanded contents of the cylinder, still retaining considerable heat,
are discharged, giving out a large part of their heat to the regenerator, which heat
is imparted to the next charge of gaseous mixture admitted through the regenerator
to the cylinder. While the action above described goes on in the upper part of the
cylinder, the lower part of the cylinder operates as a pump, drawing in charges of
air and gas and delivering them into the receptacle.
Obviously two or more cylinders may be arranged to work in conjunction with
one crank shaft, and the cylinders may be horizontal or inclined. Also the slides
which govern the passages to and from both ends of the cylinders may be of the
rotating kind, governing those passages in succession like the rotating slides used
in multiple cylinder steam engines.
When it is desired to make each cylinder double acting, it has a hot part at each
end and a cool part in the middle for the working of the piston, which has a shield
on each side of it. In this case the charges of gas and air are drawn in and
delivered to the receptacle by a separate pump.
In combining an engine such as I have described with means of generating the
combustible gas, I employ a gas producer of the kind described in the Specification
of a Patent granted to me on the 19th August 1880, No. 3374.
In this producer
n current of heated air is introduced into the heart of a body of kindled fuel, and
the gases produced partly by distillation and partly by imperfect combustion of the
fuel are conveyed to the gas inlet of the cylinder or pump of the engine. As the
gas in leaving the producer is hot I cause it to pass through regenerating apparatus,
to which it delivers a large portion of its heat before it reaches the engine, and I
cause the air which supplies the producer to pass through this regenerating
apparatus so as to take up the heat abstracted from the gas. The regenerating|
apparatus for this purpose may consist of tubes or other extended surfaces of metal,
such, for example, as the arrangement described in the Specification last referrod

page_text: to, No. 3374, of 1880, consisting of a number of metal plates dividing the
regenerating chamber into narrow parallel passages. The gas on its way from the
producer to the engine being made to pass in thin films through the first, third,
fifth, &c., of these passages, while the air on its way to the producer is made to pass
through the second, fourth, sixth, &c., in the opposito direction, the air becomes
heated and the gas becomes cooled.
By combining as above described a producer, a regenerator, and an engine, the
combustion of fuel can be applied to the production of motive power for marine
propulsion, or for other purposes for which steam engines are usually employed;
the boiler, condenser, and their adjuncts being dispensed with, and considerable
economy of fuel being effected by using its combustion directly instead of employing
it indirectly for generation of steam.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles William Siemens in the Great Seal Patent Office on the
9th December 1881.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
County of Middlesex. IMPROVEMENTS IN GAS MOTORS AND PRODUCERS."
In the Specification of a Patent granted to me on the 28th August 1860,
No. 2074, and in a Provisional Specification filed by me on the 28th July 1862,
No. 2143, I described apparatus for the production of inflammable gas and for
applying the combustion thereof for producing motivo power. My present
Invention relates to apparatus of that kind, the object of my improvements being
to simplify the construction and operation of the apparatus, and to utilise more
fully the heat developed by the combustion of the fuel employed.
I will first describe the engine in which I apply the combustion of gas to produce
motive power, premising that any inflammable gas may be employed in this engine,
but, as I will hereafter explain, I prefer to combine with the engine a gas producer
BO as to form a complete combined apparatus for the production and utilisation of
the inflammable gas.
The engine which I am about to describe may have two or more working
cylinders, and these may be single acting or double acting. In order to simplify
description, I will assume that it has one single acting cylinder placed with its axis
vertical. This cylinder consists of two parts, an upper hot part which may be
lined with plumbago, fire clay, or other refractory material, and a lower part which
is kept cool by a water casing. This cylinder is fitted with a trunk piston which
works in the lower part of the cylinder, and has on its upper side a shield that
almost fills the hot part of the cylinder when the piston is at the extreme of its up
stroke. The trunk rod of the piston passes through a stuffing box in the cylinder
bottom and is connected to a crank on the engine shaft, which, unless multiple
cylinders are employed, carries a heavy fly-wheel. From the lower end of the
cylinder there is a passage which by means of a rotating or reciprocating slide is
alternately put in communication with inlets for gas and air, regulated by suitable
cocks or valves and with a strong receptacle. As the piston makes its upstroke
air and gas are drawn into the annular space surrounding its trunk, and the mixed
air and gas are compressed by the downstroke of the piston and delivered into the
receptacle in which a considerable pressure is maintained. The receptacle is con-
veniently made of cylindrical form with a domed cover of thin sheet metal, which
in case of excessive internal pressure can give way, operating as a safety valve to
save the body of the receptacle from damage. From the upper end of the cylinder
there is a passage that by means of a rotating or reciprocating slide is alternately
put in communication with the receptacle and with a discharge outlet. In this
passage are fixed a number of wire gauze screens or pieces of metal with interstices
which constitute a regenerator of heat, and also prevent communication of flame
from the cylinder to the receptacle. In the upper end of the cylinder or of the
piston shield are provided electrodes which give an electric spark, or a platinum
wire which is rendered incandescent by a current from an inductor or other
source of clectricity to ignite the combustible charge of the cylinder. After the
engine has been for sometime at work, the heat at the upper part of the cylinder
niny suffico for effecting ignition without provision of other means for that
purpose.
The receptacle being charged with compressed mixture of gas and air, the
operation of the engine is as follows:-As the piston begins to descend the com-
pressed gaseous mixture entering the upper end of the cylinder heated in its
passage through the regenerator is ignited within the cylinder, and thus has its
volume largely expanded, whilst its pressure remains the same as that of the fluid
in the receptacle. When the piston has performed part of its downstroke, the
supply of gascous mixture is cut off by the slide, and the heated contents of the

page_text: cylinder expand, propelling the piston. When the piston has completed its down-
stroke the exhaust passage is opened by the slide, and the expanded contents of the
cylinder still retaining considerable heat are discharged, giving out a large part of
their heat to the regenerator in their passage through it, which heat is imparted to
the next charge of gaseous mixture admitted through the regenerator to the
cylinder. While the action above described goes on in the upper part of the
cylinder, the lower part of the cylinder operates as a pump, drawing in charges of
air and gas and delivering them into the receptacle.
Obviously two or more cylinders may be arranged to work in conjunction with
one crank shaft, and the cylinders may be horizontal or inclined; also the slides
which govern the passages to and from both ends of the cylinders may be of the
rotating kind, governing these passages in succession like the rotating slides used in
multiple cylinder steam engines.
When it is desired to make each cylinder double acting it has a hot part at each
end and a cool part in the middle for the working of the piston, which has a shield
on each side of it. In this case the charges of gas and air are drawn in and
delivered to the receptacle by a separate pump.
In combining an engine such as I have described with means of generating the
combustible gas I employ a gas producer of the kind described in the Specification
of a Patent granted to me on the 19th August 1880, No. 3374, and in a Provisional
Specification filed by me on the 31st August 1881, No. 3792. In this producer a
current of heated air is introduced into the heart of a body of kindled fuel, and
the gases produced partly by distillation and partly by imperfect combustion of
the fuel are conveyed to the gas inlet of the cylinder or pump of the engine. As
the gas in leaving the producer is hot it may be passed through regenerating
apparatus, to which it delivers a large portion of its heat before it reaches the
engine, and I cause the air which supplies the producer to pass through this
regenerating apparatus so as to take up the heat abstracted from the gas.
The regenerating apparatus for this purpose may consist of tubes or other
extended surfaces of metal, such, for example, as the arrangement described in the
Specification above referred to, No. 3374 of 1880, consisting of a number of metal
plates dividing the regenerating chamber into narrow parallel passages.
The gas
on its way from the producer to the engine being made to pass in thin films
through the first, third, fifth, &c., of these passages, while the air on its way to the
producer is made to pass through the second, fourth, sixth, &c., in the opposite
direction, the air becomes heated and tho gas becomes cooled. Such regenerative
apparatus may be dispensed with, the gas being cooled and cleansed by passing it
through water.
By combining, as above described, a gas producer and an engine, with or
without an intermediate regenerator, the combustion of fuel may be applied to the
production of motive power for marine propulsion, or for other purposes for which
steam engines are usually employed, the boiler, condenser, and their adjuncts being
dispensed with, and considerable economy of fuel being effected by using
its combustion directly instead of employing it indirectly for generation of
steam.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a front elevation partly in section, and Fig. 2 is an end elevation, also
partly in section, shewing a pair of engines according to my Invention. The lower
part A of each cylinder is cooled by water circulating through its casing; the
upper part B is lined with refractory material, such as fire clay; the trunk
piston C is made hollow and formed with a shield covered by refractory material
to protect the packing of the piston and the surface of the lower part of the
cylinder from heat. The pistons of the two cylinders are connected by connecting
rods D to opposite cranks on the shaft E. This shaft by means of bevil gear F
works a revolving cylindrical valve G situated in a casing between the two
cylinders. The lowest part of this casing is supplied with combustible gas, and

page_text: with air in proportions regulated respectively by stop cocks or valves
and a.
The highest part of the casing communicates with the discharge pipe d. The
middle part of the casing communicates with the reservoir R, which can be cut off
from cominunication by a stop cock H, so that the charge in the reservoir may be
retained when the engine is stopped. The reservoir R is of cylindrical form, and
has a domed cover of sheet metal, which may give way in case of excessive
pressure occurring within the reservoir. The middle space of the hollow valve G
communicates by a number of holes with the middle space of the slide casing. It
also by means of a port p' at its lower part communicates alternately with the
annular spaces of the two cylinders, this communication in each case being made
when the piston is performing the latter part of its downstroke. The interior of
the slide also, by means of a port p at its upper part, communicates alternately
with the tops of the two cylinders, this communication being in each case made
while the piston is performing the first portion of its downstroke. During the
upstroke of each piston the slide by means of a port p³ makes communication
alternately to each cylinder from the bottom of the slido casing, and by means of
a port p make communication alternately from each cylinder to the top of the
slide casing. In the passage connecting the top of the slide casing to each cylinder
is placed a regenerator_K, consisting of a number of perforated metal plates or
sheets of wire gauze. In order that gas of poor quality or gas diluted with a
large proportion of air may be employed, I use an igniting arrangement of kind
described in a Provisional Specification filed by me on the 7th December 1881,
No. 5350, which operates as follows:-L is a vessel containing a supply of hydro-
carbon oil, preferably of volatile character; from this vessel pipes lead to two
cocks 7, one for each cylinder, these cocks being caused to revolve in time with the
engine shaft by a chain M communicating motion from a chain wheel on the engine
shaft to a chain wheel of equal size on the spindle of the two cocks. The plug of
each cock has on its side a small hollow, which during one part of its revolution
presents itself under the oil pipe and receives a charge of oil. During another
part of its revolution, which is timed to correspond with the flow of gaseous
mixture to the cylinder, the hollow of the plug presents itself to the bend of a pipel
leading from the top of the cylinder to a port 2 opening into the cylinder below
the regenerator K, in which port are situated two wires of platinum P. These wires
are connected with the brushes of a commutator Q on the engine shaft, which
commutator is in electrical connection with the poles of a battery, dynamo-electric
machine, or other source of electricity. Instead of two wires to produce a spark a
single wire may be arranged to become incandescent at the proper time for ignition.
The operation of the engine is as follows:-Each piston as it ascends draws into
the annular space under it a supply of gas and air in proportion regulated by tho
cocks or valves g and a, and as it descends it forces this charge into the interior of
the revolving valve and its casing, and into the reservoir R which communicates
therewith. When either piston is at the top of its stroke the revolving valve
admits to the upper part of the cylinder a supply of the gaseous mixture from the
reservoir and valvo casing, and this passes through the generator K. At the same
time a portion of the charge passes by the pipe 2, and becomes enriched by
admixture therewith of the hydrocarbon oil delivered to it by the cock. The
enriched mixture in passing the platinum wires P, which at that time give an
electrical spark, is ignited and ignites the charge that is passing through the
regenerator into the cylinder. The mixture thus ignited expands, and acting on the
full area of the piston propels it downwards, the underside of the piston boing at
that time subject to pressure only on its annular area. When the piston has
completed its downstroko the passage is opened to the discharge pipe à, and the
expanded products of combustion then pass from the cylinder through the
regenerator, and are discharged. In their passage they give out to the regenerator
a large portion of their heat which the charge entering the cylinder for the next
stroke receives in passing through the regenerator.
As, according to the construction described, ench cylinder of the engine is single

page_text: acting, it is convenient to have for such a purpose as a marine engine more than
two cylinders in connected operation so as to avoid dead centres. Fig. 3 is a vertical
section partly through one cylinder and partly through the revolving valve; and
Fig. 4 is a plan partly in section of an engine having four cylinders working on
one shaft, each pair working at right angles, a crank opposite to the crank worked
by the other pair. The parts corresponding with those shewn in Figs. 1 and 2 are
marked with corresponding letters. The arrangement for ignition, which is also of
a kind described in the Provisional (Specification filed by mo on the 7th December
1881, No. 5350, is as follows:-To the piston of each cylinder is attached tho
plunger of a small compressing pump S, which communicates by a pipe with a
cavitys in the valve case, shewn to an enlarged scale in vertical section at Fig. 5,
and in sectional plan on Z, z, z, Z, at Fig. 6, and on Z, y, y, Z, at Fig. 7. This
cavity also communicates by pipes 81, 81, with gas supply, and by means of pipes s², &²,
with a valve box. The revolving slide is provided with annular ports or cavities
facing the cavity 8, so arranged that at each upstroke of the plunger of S gas
supplied by the pipes s', s¹, is drawn into the pump, and at each downstroke this
gas is discharged into the pipes &, 82, which are connected by a pipe forming
with them a reservoir containing the gas under pressure. In the valve box T there
is a piston kept down by an adjustable spring, the stem of the piston closing as a
valve the mouth of the pipe 82. To the space under the piston a pipe t leads from
the top of the cylinder above the regenerator K, and a passage in which aro
situated the platinum wires P leads from the same space to the cylinder under the
regenerator. When, by the action of the revolving valve G, as already described,
the gaseous mixture is admitted to the top of the cylinder above the regenerator,
the pressure communicated by the pipe tacting on the piston in the valve box T
raises that piston, and so opens the pipe &. Thereupon gas issuing from the pipe &
and mingling with the gas and air supplied by the pipe t flows through the
passage past the platinum wires P, and these give at this time a spark which
ignites the gaseous mixture passing them, and this in its turn ignites the charge
entering the cylinder through the regenerator. Fig. 8 is a vertical section of a gas
producer and scrubber, which as stated above, may be employed in combination
with engines such as I have described for supplying them with combustible gas.
The producer is a vessel lined with refractory material. At the top it has a supply
opening covered by cap U, having a flange dipping into a sand joint. At the
bottom it has an opening surrounded by inclined bars V, which rest upon a water
pipe v perforated with small holes, by which water issues to cool the bars and
generate vapour. This vapor rises along with a limited supply of air through the
incandescent fuel above, and combustible gas is produced, which collects in the
annular space u, and is led thence by a pipe to the scrubber. The scrubber is a
vessel containing in its lower part water W supplied by a pipe w, and having an
overflow w¹. The gas is caused by a perforated deflecting plate to bubble through
the water, whereby it is cleansed and cooled, and it passes by a pipe X to supply
the engine. The upper end of the vertical pipe of the scrubber is inade open and
covered by a cap scaled in water while the producer is at work. In starting the
producer this cap is removed and a chimney pipe put in its place so as to give a
draught for kindling the fuel in the producer. When the fuel is kindled the
chimney is removed and the cap substituted, whereupon the suction of the engine
continues the draught as required.
In witness whereof, I, the said Charles William Siemens, have hereunto set
my hand and seal, this Eighth day of December, in the year of our Lord
C. W. SIEMENS. (L.S.)