Use of Steam and Products of Combustion.
Year: 1887

page_text: Date of Application, 11th Jan., 1887
Complete Left, 7th Nov., 1887
Complete Accepted, 9th Dec., 1887
Use of Steam and Products of Combustion.
We, MATTHEW PIERS WATT BOULTON of Tew Park in the County of Oxford,
Gentleman, and EDWARD PERRETT of No. 8 Victoria Chambers, Westminster in the
County of Middlesex, Engineer, do hereby declare the nature of this invention to be
as follows:
In the method of working and construction of engine which we are about to
describe, we employ steam as the principal agent for working or actuating the engine,
but we employ as subsidiary to the steam, a certain portion of hot air products of
combustion or incondensible elastic fluid, which at some stage of the working is mixed
with the steam. The principal service of this air or incondensible fluid is to superheat
the steam, which it can do very powerfully, but it also to some extent assists the
steam in performance of work in the engine by its own expansion.
We provide a boiler with its own furnace for the generation of the steam, and we
provide a subsidiary vessel in which combustion is maintained at any pressure desired,
the air needed for combustion being introduced into it in regulated quantity by a
pump or suitable apparatus. In what follows we shall speak of this vessel as the
combustion-chamber.
We cause the steam which performs work in the engine, or a portion of it, to enter
among the hot gases in the aforesaid combustion-chamber, and mix with them, the
mixture of steam and hot gases thus produced passing away to perform work in the
engine. In some cases we cause the steam to pass through the combustion chamber
on its way to the first cylinder, while in other cases we cause the steam to pass through
the said chamber at a later stage, between two stages of expansion.
If the engine is non-condensing, the admixture of the incondensible gases with the
steam does no harm. If the engine is a condensing one, it is attended with a certain
disadvantage, as it necessitates some augmentation of size of the air pump.
In one form of construction we operate as follows: We maintain the combustion-
chamber at a pressure equal (or nearly so) to that of the boiler, and at one end of the
irst cylinder we cause the steam to pass from the boiler to the cylinder through the
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page_text: combustion-chamber, so that the fluid acting on this side of the piston is the hot
mixture of steam and gas previously described; while at the other end of the cylinder
we cause the steam to pass direct from the boiler to the cylinder, so that the fluid
acting on this other side of the piston is ordinary steam. Each of these two fluids is
discharged from the first cylinder into a reservoir, and the fluid from this reservoir,
being a mixture of steam and gases, performs work in a further cylinder or cylinders.
In another arrangement. we operate in like manner on both sides of the piston,
introducing alternate charges of the hot mixture of steam and gas and of pure or
ordinary steam. These alternate charges may be introduced either in separate strokes
or during portions of one stroke.
Again in one form of construction, we employ both the boiler and the combustion
or superlicating chamber at atmospheric pressure, or very near it. In this case the
engine works by the vacuum or reduction of pressure caused partly by the condensation
of the steam and partly by the cooling of the fluid.
The fuel burnt in the combustion or super-heating chamber may be of various kinds,
solid, liquid or gaseous: the important point being that the gaseous products of
combustion should be free from soot, ash or impurities. If solid fuel is employed,
coke or charcoal is a suitable substance. Liquid fuel is on several accounts well
suited for being employed in it.
Dated this 11th day of January 1887

page_text: Use of Steam and Products of Combustion.
We, MATTHEW PIERS WATT BOULTON, of Tew Park, in the County of Oxford,
Gentleman, and EDWARD PERRETT of No. 8 Victoria Chambers, Westminster, in the
County of Middlesex, 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 :-
In the method of working and construction of engine which we are about to
describe we employ steam as the principal agent for working or actuating the engine;
but we employ, as subsidiary to the steam, a certain quantity of hot gases resulting
from combustion, which are at some stage of the working mixed with the steam. The
principal service of these hot gases is to superheat the steam, which they can do very
powerfully, but they also to some extent assist the steam in performance of work in
the engine by their own expansion.
We provide a boiler with its own furnace of any known suitable kind for the
generation of the steam, and we provide a subsidiary vessel in which combustion is
maintained at any pressure desired, the air needed for combustion being introduced
into it in regulated quantity by a pump or suitable apparatus. In what follows we
shall speak of this vessel as the combustion chamber.
We cause the steam which performs work in the engine, or a portion of it to mix with
the hot gases resulting from the combustion maintained in the aforesaid chamber, the
mixture of steam and gases thus produced going to perform work in the engine. In
some cases, we cause the steam to mix with the gases on its way to the first
cylinder of the engine while in other cases, we cause the steam to mix with them at a
later stage between two stages of expansion.
If the engine is non condensing, the admixture of the incondensible gases with the
steam does no harm.
If the engine is a condensing one, it is attended with a certain amount of disadvantage
as it imposes some additional work on the air pump. In one form of apparatus we
operate as follows:-
We maintain the combustion chamber at a pressure equal or nearly so to that of the
boiler. At one end of the first or high pressure cylinder we introduce steam which
has been caused to mix with hot gases as aforesaid, while at the other end of the said
cylinder we introduce steam direct from the boiler.
Each of these two fluids is discharged from the first cylinder into a reservoir, and
the fluid from this reservoir, being a mixture of steam and gases performs work in a
further cylinder or cylinders.
In another arrangement, we operate in like manner on both sides of the piston
introducing alternate charges of the hot mixture of steam and gas and of pure or
ordinary steam.

page_text: "
These alternate charges may be introduced either in separate strokes or during
portions of one stroke.
Again, in one form of apparatus, we employ both the boiler and the combustion or
superheating chamber at atmospheric pressure or very near it. In this case the engine
works by the vacuum or reduction of pressure caused partly by the condensation of
the steam and partly by the cooling of the fluid.
When high pressures are employed, the operation of superheating which has been
described may be repeated.
A compound engine may be employed provided with numerous cylinders acting
in succession, and at each stage of expansion, or at each passage from one cylinder
to another, there may be superheating.
The fuel burnt in the combustion or superheating chamber may be of various
kinds, solid, liquid, or gaseous: the important point being that the gaseous products
of combustion should be free from soot, ash, or impurities. If solid fuel is employed,
coke or charcoal is a suitable substance.
Liquid fuel is on several accounts well suited for being employed.
Fig. 1 of the accompanying drawings shews an arrangement of steam boiler;
combustion chamber or superheater and compound engine for operating according to
our invention in the following manner.
B is a steam boiler of any ordinary construction, having a fire for generating the
steam, the products of combustion from this fire passing off by a chimney Q. Steam
taken direct from the boiler B passes by the pipe H to the valve case at the upper
end of the cylinder Cand acts on the annular area on the upper side of the differential
piston Pl.
The exhaust steam from the upper part of the cylinder C¹ passes by the pipe N
to the combustion chamber A which will be hereafter more particularly
described.
In the chamber A the steam becomes mingled with the gases resulting from the
combustion maintained in the chamber, and is thereby superheated.
From the combustion chamber A the mixture of superheated steam and gases
passes by the pipe D to the lower end of the cylinder C and acts on the full area on
the underside of the piston P¹.
The exhaust from the lower part of the cylinder C₁ passes by the pipe K
to a reservoir R whence both the ends of the low pressure cylinder Care
supplied.
The superheater A is supplied with the air required for the combustion of the fuel
by a pipe G from an air compressing pump L which may be worked as shown by an
engine supplied with steam from the boiler by the pipe M.
In the other figures of the accompanying drawings no boiler or air pump is shewn,
but it is to be understood that in all cases there is a boiler in which the steam spoken
of is generated and an air pump for supplying the air required for combustion at
suitable pressure in the combustion chamber.
Fig. 2 is
employed.
a vertical section of a combustion chamber in which solid fuel is
A is a vessel lined with refractory material and having in the middle a grate B¹ on
which solid fuel such as coke or charcoal is burnt. At the top of the vessel is a valve C
such as is used for feeding fuel to hot air engines, the pressure on this valve being
balanced when it has to be opened, by admitting steam above it by a pipe e. Air to
support the combustion is forced in by the pipe G, and steam from the boiler is
introduced above the fire at E in quantity regulated by a valve V.
In order to promote mixture of the steam with the hot gases in the combustion
chamber, the steam inlet E may be provided with a perforated mouth as shewn in
Fig. 2 which is a part sectional plan on Z of Fig. 1. The steam from the boiler
instead of being admitted laterally may be admitted centrally by a pipe passing up
through the fuel as shewn at S. Fig. 1.
Fig. 3 is a vertical section of a combustion chamber in which liquid fuel is employed.
B is the burner in which a central jet of steam supplied by the pipe b' acts as an

page_text: ejector causing the liquid fuel which is supplied by the pipe b to issue from an annular
passage surrounding the central jet.
Air is supplied by the pipe G and steam from the boiler supplied by the pipe E
mingles with the products of combustion in the chamber F. From this chamber the
mixture of steam and combustion gases by the pipe D to the engine.
Fig. 4 is a vertical section of an engine cylinder and valve arranged for admitting
steam from a boiler and the mixture of steam and combustion gases to act together in
the cylinder.
Steam direct from boiler is supplied by the pipe H and the mixture of steam
and combustion gasses is supplied by the pipe D to the valve box I in which are two
piston valves which may be worked by a cam such as is shewn in Fig. 44. The
mixed fluid passes by the pipe K into the slide case of the cylinder L' and, after
performing work in the cylinder, the exhaust passes away by the pipe M¹ to an escape
outlet or to a condenser.
Instead of working-the valves for the two fluids together as shewn in Fig. 4 they
may be worked separately as shewn in Fig. 5, in which figure the parts corresponding
with those in Fig. 4 are marked by similar letters.
Fig. 6 is a section of two engine cylinders arranged to work as a compound engine
in the following manner: Steam direct from the boiler supplied by the pipe H acts
on the upper side of the piston P¹ and the mixture of steam and combustion gases
supplied by the pipe D acts on the underside of the piston P. The exhaust from the
cylinder on both sides of the piston P¹ passes into a reservoir N supplying working
fluid which acts on both sides of the piston P² alternately the exhaust passing by a
pipe M to a condenser or discharge outlet.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, we declare that what we
claim is
1. The herein described method of superheating steam used in an engine for the
production of motive power, by causing steam generated in the boiler to mix,
either on its way from boiler to cylinder, or on its way from one cylinder to another,
with hot gases resulting from combustion maintained at a suitable pressure.
2. The construction and use of an engine provided with steam boiler, combustion
chamber and cylinders acting in succession, substantially as described with reference
to Fig. 1, wherein steam from the boiler, after acting on the annular area of a
differential piston, is superheated by admixture with products of combustion, and this
mixture, after acting on the full area of the differential piston, passes to a reservoir
for supply of the low pressure cylinder.
3. The construction and use of apparatus substantially as described with reference
to Fig. 2 whereby steam from a boiler is superheated for the purposes set forth by
mixing it with hot gases resulting from the combustion of solid fuel.
4. The construction and use of apparatus, substantially as described with reference
to Fig. 3 whereby steam from a boiler is superheated for the purposes set forth by
mixing it with hot gases resulting from the combustion of liquid fuel.
5. The construction and use of a compound engine in connection with steam boiler
and superheating combustion chamber, substantially as described with reference to
Fig. 6, wherein the high pressure cylinder is supplied at the one end with steam and
at the other end with a mixture of superheated steam and gases resulting from
combustion, and the exhaust from both ends passes into a reservoir which supplies
the low pressure or the next succeeding cylinder.
Dated this 7th day of November 1887
ABEL & IMRAY,
Agents for the Applicants.