IMPROVEMENTS IN AND RELATING TO ENGINES AND APPARATUS CONNECTED THEREWITH FOR DEVELOPING THE EXPANSIVE FORCE OF AIR OR GAS AND UTILIZING THE SAME FOR MOTIVE POWER
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Herbert Guthrie at the Office of the
Commissioners of Patents on the 18th May 1882.
HERBERT GUTHRIE of Longsight Manchester in the County of Lancaster, Civil
Engineer, "IMPROVEMENTS IN AND RELATING TO ENGINES AND APPARATUS
CONNECTED THEREWITH FOR DEVELOPING THE EXPANSIVE FORCE OF AIR OR GAS
AND UTILIZING THE SAME FOR MOTIVE POWER
"
My Invention relates chiefly to engines designed to be operated by the expansive
force of air or other gas heated under pressure, its object being to economically
convert the thermal power of fuel into mechanical power. My said invention
mainly consists in the employment of a combustion chamber or chambers into
which air and fuel are introduced and burnt under pressure, the said combustion
chamber or chambers being connected with a cylinder or cylinders in such a
manner that the products of combustion passing from the fire are employed as the
elastic medium for driving the machinery, the object being to expand the air so
used direct by the combustion of cheap solid fuel, under pressure, and thereby to
avoid the loss of heat experienced with the steam-engine and to avoid the loss of
volume by chemical combination as in the gas-engine, as well as the great expense
of the gas used and the impossibility of locomotion owing to the space required
for storage.
In carrying my said invention into practice I prefer to employ closed com-
bustion-chambers provided with feed and exit pipes, safety valve, and other
mountings, and also with a door or other contrivance so arranged as to permit
fresh fuel to be introduced against a pressure within. The feed pipe, or pipe for
supplying the air, is so placed in reference to the fuel as to act as a tuyere so as to
force the supply of air through the fuel, or if powdered fuel be used a multiple or
single blow-pipe arrangement may be employed as may be found best for the
particular kind of fuel used.
The regulation of speed and power may be effected by simply limiting the
amount of air injected through the feed pipe and fuel, or by pumping a constant
supply of air and allowing a greater or smaller portion to pass by a connecting
pipe, direct to the exit pipe or to the upper part of the combustion-chamber
without passing through the fuel, so as to modify the heat of the portion coming

page_text: from the fuel and adjust the expansion and pressure to the required extent. The
contrivance for effecting this result may be similar to the ordinary governor, except
that a three-way valve will be required instead of a two-way valve so as to direct,
and not throttle, the current of air.
For engines which are required to work for long periods, such as locomotives and
tramway engines, with double cylinders, two or more combustion-chambers may
be used, with simple air-tight cap or flange doors or covers of any suitable
construction and secured in any well known manner, and the feed and exit pipes
may be provided with a stop-cock or valve so that one of the combustion-chambers
may be entirely disconnected and relieved of pressure while being re-fed, meanwhile
the other chamber or chambers will be quite capable of keeping the engine supplied,
without being subjected to too great a heat. For constant work the fires should
be kept at a low temperature so as not to cause clinkering, a gentle and quiet
combustion being preferable producing only dust and soft ash as a residue easy of
removal. The air-pump and power-cylinder may be upon the same rod, which rod
may be hollow for the circulation of water or air. If desired, the feed air for the
engine may be sucked in through the piston of the air-pump thus accomplishing
the double purpose of cooling the pistons and rod and carrying back to the engine
the heat thus collected. For starting the engine a reserve of compressed cold air
may be provided and communications with the combustion chambers so arranged
as to admit of injecting a portion of the air and immediately creating a working
pressure in the said chambers. In order to prevent the formation of carbonic oxide
and ensure perfect combustion, injections may be made at different levels in the
combustion-chambers, so that the injected air may not traverse so much of the
incandescent fuel as to cause the formation of carbonic oxide or in order to consume
any carbonic oxide which may have formed lower down.
My said invention also comprises the use of refractory coverings, such as asbestos
or fire-clay as may be found most suitable and the circulation of water or air
through various parts of the apparatus; also the use of compound cylinders and
condensers and air injectors for the supply of air while the machinery is standing.
It is also anticipated that the aforesaid injector for supplying air under pressure
may be useful for other furnaces besides those used for producing mechanical power
as above stated.