An Improved Method of and Apparatus for Producing Compressed Air.
Year: 1895

page_text: Date of Application, 6th June, 1895
Complete Specification Left, 6th Mar., 1896-Accepted, 11th Apr., 1896
PROVISIONAL SPECIFICATION.
An Improved Method of and Apparatus for Producing
Compressed Air.
We, GEORGE JAMES, of Leicester Villa, Gore's Lane, Freshfield, near
Liverpool, not in business, and FRANCES MARY JAMES, his wife, of the same
address, and not in business, do hereby declare the nature of this invention to be
as follows:-
This invention relates to an improved method of and apparatus for producing
compressed air for employment in air-engines and for other purposes.
According to this invention atmospheric air is subjected to a preliminary
compression in an air-compressor of any suitable type. Air thus compressed in
this primary compressor is led to a secondary or main compressor in which a
portion of the volume of air under such preliminary pressure is subjected to a
greater pressure. From this secondary compressor air at a high pressure is cooled
by being passed through suitable cooling apparatus and is then conducted through
a heating chamber or furnace, in which it is heated, and at an increased
temperature and consequently greater volume it is admitted to the engine or other
apparatus in which it is to do work.
The preliminary compressor may be driven by an air-motor of ordinary construc-
tion actuated by the exhaust air of the secondary compressor, such exhaust air
being first passed a cooling apparatus and subsequently through the heating
chamber or furnace before mentioned, in which its temperature and volume are
increased.
The secondary or main compressor preferably consists of three cylinders arranged
in tandem, the three pistons or plungers of said cylinders being mounted upon a
common piston-rod. The central or intermediate cylinder is preferably of larger
diameter than the outer cylinders and is employed as a driving or working cylinder,
the outer cylinders alternately acting as working cylinders and air compressors.
Air compressed in the primary compressor is admitted behind the piston of the
central or larger cylinder and behind the piston of one of the outer cylinders, and
in front of the piston of the other outer cylinder. The air in this latter cylinder
is compressed in proportion to the difference existing between the combined areas
of the pistons of such central cylinder and outer working cylinder and that of the
other outer and compressing cylinder. In the return stroke the outer cylinder
which was previously a compressing cylinder becomes a working cylinder, whilst
the outer cylinder which was previously a working cylinder now becomes the
compressor, the central cylinder always acting as a working cylinder. The
exhaust air from the central cylinder, as before mentioned, is cooled and then
heated and expanded and made to do work in driving the primary compressor.
The admission and exhaust valve of the central cylinder is preferably operated by
tappets mounted upon the piston-rod and connected with the valve spindle through
levers, rollers working on inclined planes, rolling weights, or other suitable
mechanism. The air admission and outlet valves of the outer cylinders may be of
the ordinary non-return type. A regulating or non-return valve is disposed upon
the exhaust pipe leading from the central cylinder to the primary compressor
motor through a coil within the beating chamber, so that when the pressure in such
coil exceeds that of the exhaust such exhaust is liberated into the atmosphere.

page_text: The cooling of the air compressed by the above described apparatus is preferably
effected through the agency of the exhaust or waste air of different portions of the
apparatus being directed in combination with liquids capable of rapid evaporation
onto the pipes or other conduits conveying such air.
The means for heating the air compressed in the above described apparatus
consists of a chamber or furnace preferably heated by means of one or more
atmospheric gas burners, and provided with an uptake for the products of combus-
tion, and an air-tight door. Within this chamber are disposed three tubular coils
through which are respectively passed the air compressed in the above described
apparatus, the exhaust air of the central cylinder above mentioned, and the gas
employed to heat the chamber. The gas burner or burners may be arranged to
swing outwardly by means of bevel wheel or other gearing when the door of the
chamber is opened, and the chamber is preferably provided with one or more
salety-valves adapted to relieve any undue pressure which may arise within it.
Such door, burners, and safety-valves may be connected together by suitable
mechanism so as to work simultaneously, the object of this arrangement being to
guard against the danger of the chamber becoming inadvertently charged with gas
and the consequent liability of explosion.
Dated this 4th day of June 1895.
J. A. COUBROUGH,
Registered Patent Agent,
10 St. George's Crescent, Liverpool, Agent for the Applicants.
CUMI LEID
DIBUITICATION.
An Improved Method of and Apparatus for Producing
Compressed Air.
We, GEORGE JAMES, of Leicester Villa, Gore's Lane, Freshfield, near
Liverpool, not in business, and FRANCES MARY JAMES, his wife, of the same
address, and not in business, do hereby declare the nature of the said 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 an improved method of and apparatus for producing
compressed air for employment in air engines and for other purposes.
According to this invention atmospheric air is subjected to a preliminary
compression in an air-compressor of any suitable type. Air thus compressed in
this primary compressor is led to a secondary or main compressor in which a
portion of the volume of air under such preliminary pressure is subjected to a
greater pressure. From this secondary compressor air at a high pressure is cooled
by being passed through suitable cooling apparatus, and is then conducted through
a heating chamber or furnace, in which it is heated, and at an increased
temperature and consequently greater volume it is admitted to the engine or other
apparatus in which it is to do work.
In the drawing hereto annexed, and which will now be referred to in describing
this invention, an arrangement of apparatus suitable for carrying the invention
into operation is illustrated diagrammatically, it being understood that the
individual or component parts of such apparatus are of ordinary construction, in
respect of which no novelty is claimed.
In the drawing, A denotes the preliminary compressor arranged in triplicate, in
which atmospheric air is subjected to primary compression, such compressors being
driven by motors a of ordinary construction actuated by the exhaust air of the
secondary compressors hereafter referred to. Air enters the compressors A by the
valves a¹ and is delivered thereby through the valves a³ into the pipes a³ which
conduct it to the secondary compressors B.

page_text: The secondary compressors B are arranged in triplicate, each compressor
consisting of two cylinders of equal stroke but unequal diameter. The cylinders b
having the larger diameter are termed the working cylinders, the cylinders b²
having the smaller diameter are termed the compression cylinders. Air compressed
in the primary compressors A is admitted by the pipes a³ and valves 62 behind the
piston of the cylinder 6 and in front of the piston of the cylinder & simultaneously.
The piston in the cylinder 6 having the larger diameter is carried to the end of the
cylinder and as the pistons of both cylinders band b₁ are carried by a common
piston rod the charge of air in the cylinder 6' is compressed in proportion to the
difference existing between the combined areas of said pistons, and ejected through
the valves 63 into the pipe 6 by which it is conveyed to the cooler C. The
admission and exhaust valve of the working cylinder b is preferably operated by
tappets mounted upon the piston rod and connected with the valve spindle through
levers, rollers working on inclined surfaces, rolling weights, or other suitable
mechanism which will operate the valve automatically upon the completion of each
stroke of the working piston. The air admission and outlet valves of the
cylinders may be of the ordinary non-return type. The exhaust air from the
working cylinder bis conducted by the pipe 65 to the cooler C and from thence, by
the pipe 6 to the heater D, from which it is led by the pipe 6' to the motors a
which it operates. A regulating or non return valve is disposed in the exhaust
pipe 6, so that when the pressure in such pipe and its continuations 66 and 67
exceeds that of the exhaust such exhaust is liberated into the atmosphere.
The cooling of the air compressed by the above described apparatus is preferably
effected in a cooler indicated by C. Compressed air from the compressors B
passes through a coil C₁ disposed in said cooler, the exhaust air from the
compressors B also passing through a similar coil in the cooler C.
The cooling
effect is preferably obtained by allowing water or other liquid capable of rapid
evaporation to drip from a container onto the coils, in conjunction with exhaust air
received from the motors a or other part of the apparatus.
From the cooler C the compressed air from the compressors B and the exhaust
air therefrom is led by the pipes c_and 6 respectively to a heater D. The
compressed air from the compressors B passes through a coil D¹ disposed in said
heater, the exhaust air from the compressors B also passing through a similar coil
in the heater.
The heater D consists of a chamber or furnace preferably heated by means of
one or more gas burners, and provided with an uptake for the products of
combustion, and an air-tight door. Within this chamber are disposed the coils for
conveying the compressed and exhaust airs above referred to and a third coil
through which passes the gas which is burned in the chamber. The gas burner or
burners may be arranged to swing outwardly by means of bevel wheel or other
gearing when the door of the chamber is opened, and the chamber D is preferably
provided with one or more safety valves adapted to relieve any undue pressure
which may arise within it. Such door, burners, and safety valves are preferably
connected by suitable mechanism so as to work simultaneously, the object of this
arrangement being to guard against the danger of the chamber D becoming
inadvertently charged with gas, and the consequent liability of explosion.
From the heater D the air compressed in the compressors B, cooled in C, and
heated in D, is led by the pipe D2 to the motor E or any other apparatus where it
is to be utilised.
Now, supposing an effective pressure of air of one atmosphere be applied to the
motors a and that the diameter of the pistons working in the motors a as compared
with the diameter of the pistons in the compressors A be such that air at two
atmospheres is produced in the compressors A, air at two atmospheres will then
flow into and fill the cylinders b and b. Now suppose the diameter of the pistons
in the cylinders 6 be twice the diameter of the pistons in the cylinders 6', the area
of the pistons in 6 will be four times the area of the pistons in 6', and therefore the
pressure of two atmospheres on the pistons in the cylinders 6 will compress the air

page_text: at two atmospheres in the smaller cylinders until it sustains a pressure of eight
atmospheres. Air at such pressure of eight atmospheres is then conducted through
the cooler C in order that it may be densified and in order that the heater D
a medium
through which it is subsequently passed may be maintained at
temperature.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The improved method of producing compressed air herein described, which
method consists in subjecting atmospheric air to compression in a primary air
compressor which is operated by the exhaust air of a secondary air compressor
after the same has been successively cooled and densified and heated and expanded,
then subjecting the air thus compressed in such primary compressor to compression
in said secondary air compressor in which such air is made to compress itself by
means of cylinders and pistons having different diameters, and then conveying such
compressed air through a cooler and a heater wherein it is successively densified
and expanded, substantially in the manner herein described with reference to the
drawing hereto annexed.
2. The combination of apparatus substantially as herein described and illustrated
diagrammatically in the annexed drawing for producing compressed air substantially
in the manner herein described.
Dated this 5th day of March 1896.
J. A. COUBROUGH,
Registered Patent Agent,
10 St. George's Crescent, Liverpool, Agent for the Applicants.