IMPROVEMENTS IN STEAM AND CALORIC ENGINES
Year: 1864

page_text: PROVISIONAL SPECIFICATION left by Matthew Piers Watt Boulton at
the Office of the Commissioners of Patents, with his Petition, on the
30th April 1864.
I, MATTHEW PIERS WATT BOULTON, of Tew Park, Oxfordshire, do hereby
declare the nature of the Invention for "IMPROVEMENTS IN STEAM AND CALORIC
ENGINES," to be as follows:-
The object of this Invention is to employ heat for the production of motive
power more economically than is done in the steam engine as now con-
structed. It is well known that according to the present construction of
engines and furnaces, a considerable per-centage of the heat generated
the combustion of the fuel is carried off by the gases discharged into the
chimney..
'
The object of the method now described is to save this heat, and render it
efficient in working the engine. The following is the method employed for
this purpose:-When the engine is in motion I employ it to work a force
pump, which forces the air into the chamber where combustion takes place,
and onwards into the water contained in the boiler. The heated gases after
issuing into the water are made to pass through a number of small orifices,
and so to rise in numerous currents through the water, communicating heal
to it in their passage as the bubbles of steam do in rising through the water
in an ordinary boiler. As the air is forced through the force pump at the

page_text: ordinary temperature of the atmosphere, while when it acts on the piston its
temperature is much bigher; there is gain of power in this part of the
In fact the engine is a combination of the steam engine and the
process.
caloric engine.
The method above described is applicable, whatever be the substance
employed, for combustion, whether this be solid as coal, coke, wood, or
liquid such as petroleum, naptha, oils of various kinds, or gaseous as
hydrogen, carburetted hydrogen, or carbonic oxide.
The method of proceeding may be modified as follows:-Inflammable gas
(say, hydrogen or carburetted hydrogen) or inflammable vapour (such as the
vapour of petroleum, naptha, or oils) may be generated in a separate vessel,
and this inflammable gas or vapour may be forced along a tube into a
chamber, in which it mixes with air or any other gas, forming with it a com-
bustible mixture forced into the same chamber through another tube. In
this chamber the combustible mixture of gases is ignited and forced onwards
into the water contained in the boiler, rising through it in the manner pre-
viously described. When there is a sufficient supply of cold water, the
heated volume of steam and gases after having performed its work on the
cylinder, may be admitted into a condenser or cool chamber, where the steam
will be condensed and the hot gases greatly reduced in bulk. From this
chamber they will be extracted by an air pump. The friction of the force
pump which injects air into the boiler may be utilized as a source of heat;
i.e., by imparting heat to the water before it is introduced into the boiler, or
where petroleum (or any similar liquid) is used by imparting heat to this."
This will serve to keep the force pump cool, which is desirable. As in this
method the heat is applied to the interior of the boiler, it will be proper to
protect the external surface of the boiler in such a way as to obstruct the
passage of heat. The covering employed for this purpose may be made
moveable, so that when desired heat may play on the outside of the boiler:
There are a great number of minor details of arrangement into which I do
not enter, as these may be varied in a number of ways, and do not affect the
principle of the method. The heated gases instead of passing into water, may
pass into a receptacle void of water, and issue thence to work the engine by
their pressure. In this case the engine is solely a caloric engine. The
intense heat of the gases on issuing from the combustion chamber is capable
of being moderated to any required degree by forcing an additional supply of
air into the receptacle. Where there is a sufficient command of cold water,
the heated gases after they have performed their work in the cylinder can be

page_text: admitted intoja condenser or refrigerator, and extracted thence in their cooled
and contracted state by an air pump.
The above method of employing heat is applicable, whatever be the nature
of the substance used, for combustion, whether this be solid, fluid, or gaseous;
but it is more particularly applicable where a liquid, such as petroleum, or a
gas, such as hydrogen, is used.