IMPROVEMENTS IN AND CONNECTED WITH STEAM ENGINES
Year: 1884

page_text: I ROBERT MUDGE MARCHANT of 69 Fenchurch Street in the City of London,
Civil Engineer do hereby declare the nature of my invention for IMPROVEMENTS
IN AND CONNECTED WITH STEAM ENGINES to be as follows:-
In the Specification of former Letters Patent granted to me dated the 26th April
1883 N° 2120 I described a method or process and means whereby nearly the.
whole of the steam used in a steam engine cylinder or cylinders was retained and
circulated and returned to the boiler partly in the state of steam and partly as
condensed water. That method or process was carried out, as described in the said
Specification, by taking off a portion of the steam from the engine cylinder as soon
as it had done its work at high or full pressure and returning this portion by means
of pumps to the boiler and by applying the remainder of the steam for working the
engine by expansion and vacuum and then condensing this steam, the water
resulting from such condensation being passed on with air or other gas or vapor to
the said pumps so as to saturate the steam therein, this saturated steam being
returned by the pumps to the boiler.
.
My present invention consists of improvements upon my said former invention
whereby my said method or process is more efficiently carried out.
According to my present invention I allow that portion of the steam which is
taken off to the pumps as described in my former Specification to expand in the
firat pump of the series, that is to say, in the pump to which such steam is
delivered. The power of the engine is thus increased beyond the power com-
municated by the engine cylinders, because the expansive action in this first pump
is a power in excess of the work of compression on the series of pumps, and a power
above that excess of power over work which the mere condensation of a portion of
such steam in the pumps would effect. The steam therefore gives out to power in
the pump an excess of pressure above that pressure which has subsequently and on
the return stroke to be put into it, whilst in the following pumps of the series the
air-spring gives back in the pump and on the return stroke the same pressure, which
had previously been put into it.
I now confine the first pump of the series to operation on steam only, instead
of on steam, condensation water, and air (or gas) as described in my former
specification, and I supply the condensation water and air immediately beyond the
delivery or force valve of this pump so that these ingredients of my mixture of
CD 071

page_text: steam, water and air come into action on the return stroke of the pump piston and
when the force valve has been opened by such stroke but not otherwise. The
action of the expanded steam in the first pump is thus properly effected.
I deliver the steam, condensation water and air into a passage leading from the
force valve of the first pump to the second pump in such order that the steam
valve is in advance of the condensation water valve, and this valve is in advance
of the air valve.
I employ a separate pump to deliver the condensation water instead of delivering
it by the same pump as delivers the air.
I also employ a small air pump to make good any waste of the original charge of
air in the pumps; this pump delivers its air into the passage above described
between the first and second pumps of the series of pumps.
According to a further part of my present invention I cut off the supply of steam
to the high pressure cylinder before the arrival of the piston therein at the end of
its stroke so as to obtain an interval of time between the delivery of steam from
the high pressure cylinder to the first pump and the opening of the valve which
delivers the remainder of the steam to the low pressure cylinder.
Another part of my present invention relates to the check valve used in
conjunction with the operating valve of the high pressure cylinder This check
valve is situated between the boiler and the operating valve and is worked in
equilibrium by means of a passage formed through it for the purpose and I make
it adjustable by means of screws or otherwise so that the supply of boiler steam to
the said operating valve can be cut off for any desired portion of the revolution of
the, engine.
Another improvement consists in delivering the air which is withdrawn by means
of the air pump from the surface condenser under the grate bars or other suitable
part of the engine furnace so as to assist the combustion therein..
As part of the general arrangement of my improved engine I fix the cylinders,
when the engine is double acting, respectively on the two sides of the same bed
plate and I place the series of pumps on the same bed plate and I work these pumps
from a crank between the two cylinder cranks the pump crank thus forming a third
and central crank on the engine shaft. I arrange the pumps over. each other in as
it were two stories.
"
The improvements herein before described apply not only to the special engine
described in my former specification and therein called the "superior application
but also to ordinary engines adapted to my former invention and called in the said
specification the "inferior application."

page_text: Improvements in and Connected with Steam Engines.
"
I ROBERT MUDGE MARCHANT, of 69 Fenchurch. Street, in the City of London,
Civil Engineer do hereby declare the nature of my invention for "IMPROVEMENTS
IN AND CONNECTED WITH STEAM ENGINES and in what manner. the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
-
1.
In the Specification of former Letters Patent granted to me dated the 26th April
1883 No 2120 I described a method or process and means whereby nearly the
whole of the steam used in a steam engine cylinder or cylinders was retained and
circulated and returned to the boiler, partly in the state of steam and partly as
condensed water. That method or process was carried out, as described in the said
Specification, by taking off a portion of the steam from the engine cylinder as soon
as it had done its work at high or full pressure and returning this portion by
means of pumps to the boiler and by applying the remainder of the steam for
working the engine by expansion and vacuum and then condensing this steam the
water resulting from such condensation being passed on with air or other gas or
vapor to the said pumps so as to saturate the steam therein, this saturated steani
being returned by the pumps to the boiler..
..
My present invention consists of improvements upon my said former Invention
whereby my said method or process is more efficiently carried out."
'
I confine the first pump, of the series of pumps to operation on steam only,
instead of on steam, condensation water and air (or gas) as described in my former
Specification, and I supply the condensation water and air immediately beyond the
delivery or force valve of this pump so that these ingredients of my mixture of
steam, water and air come into action on the return stroke of the pump piston and
when the force valve has been opened by such stroke but not otherwise. The
action of the expanded steam in the first pump is thus properly effected.
I deliver the stean, condensation water, and air, into a passage leading from the
force valve of the first pump to the second pump in such order'that the steam
valve is in advance of the condensation water valve and this valve is in advance of
the air valve.
I employ a separate pump to deliver the condensation water instead of delivering
it by the same pump as delivers the air.
I also employ a small air pump to make good any waste of the original charge
of air in the pumps; this pump delivers its air into the passage above described
between the first and second pumps of the series of pumps.
.
According to a furtlier part of my present invention I cut off the supply of
steam to the high pressure cylinder before the arrival of the piston therein at the
end of its stroke so as to obtain an interval of time between the delivery of steam
from the high pressure cylinder to the first puinp and the opening of the valve
which delivers the remainder of the steam to the low pressuré cylinder.
Another part of my present invention relates to the check valve used in
conjunction with the operating valve of the high pressure cylinder. This check
valve is situated between the boiler and the operating valve and is worked in

page_text: equilibrium by means of a passage formed through it for the purpose and I make
it adjustable by means of screws or otherwise so that the supply of boiler steam to
the said operating valve can be cut off for any desired portion of the revolution of
the engine.
As part of the general arrangement of my improved engine I fix the cylinders
when the engine is double acting respectively on the two sides of the same bed
plate and I place the series of pumps on the same bed plate and I work these
pumps from a crank between the two cylinder cranks the pump crank thus forming
a third and central crank on the engine shaft. I arrange the pumps over each
other in as it were two stories.
The improvements herein before described apply not only to the special engine
described in my former specification and therein called the "superior application'
but also to ordinary engines adapted to my former invention and called in the
said Specification the "inferior application."
The annexed drawings represent a double acting engine in which my present
improvements are embodied."
-
Figure 1 is a side elevation, Figure 2 a plan and Figure 3. an end elevation.
Figure 4 is a vertical section on a larger scale of one of the pairs of cylinders
(which are shown as arranged tandem fashion) and of the valves connected
therewith. Figure 5 is an elevation also on a larger scale and partly sectional
illustrating the inlets for steam condensation water and air into one of the pipes
leading from the first pump to the second pump. Figures 6 and 7 are respectively
an elevation and a plan on a still larger scale showing the pumps and their
connections. a a are respectively the small or high pressure cylinders of the two
tandem pairs and b, 6 the large or low pressure cylinders of the same. The pistons
of the two cylinders of the same pair are shown as mounted on the same rod c.
d, d are the rods connecting the pistons with the crank shaft e. f is the steam.
supply pipe from the boiler; g the starting valve; h, h the branches for the
cylinders a, a respectively. Each of these branches delivers the steam to a check.
valve (Figure 4) which is worked in equilibrium by means of a passage formed
through it for the purpose. These check valves govern the supply of steam to the
operating valves % of the cylinders a, a and are adjustable by means of the screw
so that the supply of steam to the valves k can be cut off for any desired portion
of the revolution of the engine. m is the valve of the large or low pressure
cylinder. The valves are so arranged that the supply of steam to each cylinder a
is cut off before its piston has reached the end of its stroke; there is thus an
interval of time between the delivery of steam from the cylinder a to the first
pump and the opening of the valve m which delivers the remainder of the steam
to the cylinder b. n is the exhaust valve of the low pressure cylinder. o is the
exhaust pipe common to both of the low pressure cylinders; this pipe o leads to a
condenser. P, p are the pipes taking off the steam from the high pressure cylinders
to the first pump q of the series before or soon after the steam begins to be applied
to expansive action in the said cylinders. Branch pipes r lead from the pipes p, p
to the valves m of the low pressure cylinders. The two pipes p, p from the two
high pressure cylinders a, a communicate respectively with the two ends of the
first pump q which is therefore a double acting pump. a is the second pump the
two ends of which are respectively connected with the two ends of the first pump q
by the pipes t, t¹ the inner end of the first pump being connected with the outer
end of the second pump and vice versa. In connection with the pipe t is a pipe u
supplied with condensation water by a pump which is connected with the
condenser by a pipe w; and in connection with the same pipe t is another pipe x
supplied with air by means of the pump y. The pipes t, u and x are each fitted
with a valve the order of the three valves being such that the steam from the first
pump g enters the second pump s in advance of the condensation water from the
pipe and that this condensation water enters the pump s in advance of the air
from the pipex. The pipe t¹ communicating with the opposite end of the pump 8
has similarly connected with it a condensation water supply pipe ul and an air

page_text: supply pipe the pipe, u¹ being supplied by a pump v¹ connected with the
condenser by a pipe w and the pipe x¹ being supplied by a pump y¹.
The pump 8
pumps the steam saturated with the condensation water to the next pump z of
the series, this pump in the arrangement shown being the last pump, but there
may be any required number of pumps, the pumping being effected by what is
known as the stage process of pumping by which the steam is gradually compressed
to the required pressure. z¹, z³ are the pipes communicating respectively between
the two ends of the pump 8 and the corresponding ends of the pump z The
pump pumps the compressed saturated steam through the pipe 23 back into the
boiler, this pipe being fitted with a selfacting lift valve. is an air chamber
intercalated in the pipe 23. 2 is an air pump communicating by the pipe 2 with
the condenser to free the latter of any accumulation of the air which becomes
separated from the steam therein; this air pump may discharge the air either into
the atmosphere or under the grate bars or other suitable part of the engine furnace
so as to assist the combustion therein. All the pumps are worked from the crank
shaft e which has a third crank as shown between the two cylinder 'cranks. When
the engine is at work and the pumps & and z have received a sufficient charge of
air the air pumps y, y' only make good the waste of this original charge. The
outlet valves or ports for the saturated steam or steam and water from the pumps s
and are at the bottom of the pumps; the air remains in the pump clearances and
on the return strokes of the pump pistons it acts as an air spring giving out the
pressure which has been communicated to it, only the excess air passing forward
with the steam and water.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is
1. The combination of parts constituting a steam engine arranged and acting as
bereinbefore described and shown in the annexed drawings.
2. As improvements in steam engines of the kind described in the Specification
of my former Letters Patent No 2120 of 1883-(a) Arranging that the first
pump of the series shall be limited to operation on steam only, the condensation.
water and air.being supplied beyond the force valve of this pump. (b) Arranging
that the steam condensation water and air shall be delivered into a passage leading
from the force valve of the first pump to the second pump, the steam valve being
in advance of the condensation water valve and this valve being.in advance of the
air valve. (c) Arranging that the condensation water shall be delivered by a
separate pump instead of by the pump. that delivers the air.. (d) Employing an
additional air pump to make good any waste of the original charge of air in the
pumps. (e) Arranging that the supply of steam to the high pressure cylinder shall
be cut off before its piston arrives at the end of its stroke for the purpose described.
(f) Making adjustable the check valve to the operating valve. All as and for
the several purposes set forth.