An Improved Engine for Converting Heat into Mechanical Energy.
Year: 1890

page_text: Date of Application, 2nd Aug., 1890
Complete Specification Left, 2nd May, 189-Accepted, 6th June, 1891
PROVISIONAL SPECIFICATION.
An Improved Engine for Converting Heat into Mechanical Energy.
JOHN POLLITT Engineer of 43 Lower Mosley Street Manchester and JOHN
MANGNALL Civil Engineer of Harpurhey Manchester both of the County of
Lancaster do hereby declare the nature of this invention to be as follows:-
Atmospheric air or other gas or mixture of gases is enclosed within a vessel or
tube or system of vessels or tubes communicating with each other and preferentially
filled with such air or gases in a highly compressed state. These vessels or tubes
are subjected to the heat of an ordinary furnace or other source of heat and are in
communication with two hydraulic vessels containing water or other suitable liquid
and so arranged that the pressure generated in the heated air vessels or tubes can
be conveyed to them alternately by means of valves-these hydraulic pressure
chambers are further connected and communicate with a hydraulic cylinder on the
opposing sides of a piston with which it is fitted. The differential pressure between
the hydraulic pressure chambers by reason of the alternate direction of the heated
compressed air into them resulting in motion of the hydraulic engine piston which
motion is conveyed and used externally by any of the already known and used
devices for that purpose. In order that the water or.other liquid in the pressure
chambers and cylinder may be kept sufficiently cool, the return of the liquid from
the latter to the former at each back stroke may be made to take a separate path
to that by which it enters the cylinders from the pressure cylinders such cooled
liquid returning being used to absorb any residual excess of heat retained by the air
occupying the pressure chambers after it has forced the piston to its extremity
and thus increase the differential pressures on opposing sides of the piston and
augment the useful effect.
Another portion of this invention deals with the employment of the waste or
latent heat of steam voided by or from the exhaust of ordinary steam engines-
in this case the vessels or tubes containing air or gas compressed or otherwise are
enclosed within a larger vessel into which the exhaust steam is directed, the heated
air from the vessels or tubes being used in connection with the hydraulic pressure
chambers and cylinder as already described. In a like manner waste heat from
other sources may be thus utilized.
A further portion of this invention dispenses with the air tubes and steam at high
pressure .e. above atmospheric pressure is conveyed direct into the hydraulic
pressure chambers such steam being cut off expansively and returned back to the
boiler in a cooled state in contra distinction to a condensed state, condensation in
this case being as far as practicable avoided.
Dated this 2nd day-of August 1890.
JOHN POLLITT.
JOHN MANGNALL.
COMPLETE SPECIFICATION.
An Improved Engine for Converting Heat into Mechanical Energy.
JOHN POLLITT of 43. Lower Mosley Street Manchester, Engineer, and JOHN
MANGNALL of 40 Staveley Street Harpurhey Manchester, Civil Engineer 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 :-
A closed vessel of sufficient capacity is charged with atmospheric air or other
gaseous fluid at a pressure exceeding the normal pressure of the atmosphere and

page_text: where very high pressures are employed this vessel is constructed preferentially of
a number of tubes communicating internally and freely with each other—this vessel
is subjected to the action of heat obtained from.usual sources and is hereinafter
called a
generator," connected with this generator are two other closed vessels
hereinafter called "pressure chambers" of much smaller capacity than the
generator and such connections are intercepted by means of valves so contrived
that the connection of each pressure chamber with the generator shall be separate
and alternate these pressure chambers are further connected freely with a cylinder
fitted with a reciprocating piston such connection of each pressure chamber being
on opposing sides of the said piston--the pressure chambers and cylinder. are
charged with, water or other liquid and worked hydraulically.
The air or other gaseous matter contained in the generator becoming heated
above the normal temperature increases its internal pressure and communication
being made by the valve of one of the pressure chambers the liquid contained
therein becomes subjected to the superior pressure of the generator and forces the
piston of the cylinder to its extremity when on reversing the action of the valves the
second pressure chamber receives the superior pressure from the generator and
the first one in the meantime cooling partly by means of the water returning from
the cylinder the pressure in the pressure chamber first opened becomes reduced
and the piston thus receives a reciprocating motion which is conveyed externally by
means already well known and employed. In order that the liquid in the pressure
chambers and cylinder may be kept sufficiently cool the return of the liquid from
the cylinder to the respective pressure chambers at each back stroke may be made
to take a separate and more circuitous course than that by which it enters the
cylinder such cooled liquid aiding the contraction or reduction of pressure within
its "
pressure chamber"
and thereby differentiating the temperatures of the
contents of the two pressure chambers and thereby increasing the differences of
pressures within them and consequently evolving more power through the piston.
An application of the foregoing is to connect it to existing steam engines in the
place or substitution of the ordinary condenser in this case the tubular generator is
charged with aëriform matter under as high pressures as practicable and is enclosed
within an outer vessel into which the exhaust steam is discharged the heat being
utilized as above described and the resulting condensed liquid returned to the
steam boiler by pumps or other ordinary contrivances as the range of temperatures
in this instance is low and in order to secure any useful vacuum in the steam engine
cylinder the pressure chambers must be proportionally enlarged in relation to
the size of their cylinder so that the necessary amount of expansion through the
heating of the compressed air within the generator' may equal the volume of
capacity of the hydraulic cylinder.
27
Another portion of the invention abandons the use of the generator' and
substitutes the ordinary steam boiler, in this case the steam is admitted alternately
into each "pressure chamber" direct from the steam boiler cach pressure. chamber
being provided with a second connection with the steam boiler & likewise provided
with valves worked alternately and opened and closed simultaneously with those
admitting steam to the same pressure chamber & for the purpose of returning to the
steam boiler the additional water resulting through condensation of the steam.
In order to further elucidate this invention reference is made to the accompanying
drawings.
Fig. 1 is a plan of the invention as applied in connection with steam
engines and
.
Fig. 2 is an end view of the same shewing the tubular "generator," the same
letters referring to the same parts in both.
'
FF is the foundation S. steam engine cylinder E exhaust steam pipe leading
into chamber containing tubular "generator" G G G. P C P C. are the
pressure chambers
in connection with the hydraulic cylinder H: Gand
alternately in connection with the generator G by means of valves in
valve box V.
:

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is-
1st. The system of employing highly compressed air heated in connection with
hydraulic pressure chambers and engine as herein described.
2nd. The employment of steam direct into the hydraulic chambers as herein
described.
3rd. The system of compounding steam engines with the generator pressure
chambers and hydraulic cylinder as hercin described.
4th. The combination herein described of a pressure chamber or pressure
chambers in connection with a cylinder & piston worked hydraulically as applied
to caloric motors..
Dated hit da. of 1001
JOHN MANGNALL.
JOHN POLLITT.