A METHOD OR PROCESS FOR THE RETENTION AND CIRCULATION OF STEAM IN ITS APPLICATION TO ENGINE D PROVISIONALATION
Year: 1883

page_text: LETTERS PATENT to Robert Mudge Marchant of Fenchurch Street in the City
of London Civil Engineer for an Invention of "A METHOD OR PROCESS FOR
THE RETENTION AND CIRCULATION OF STEAM IN ITS APPLICATION TO ENGINE
D
PROVISIONAL SPECIFICATION left by the said Robert Mudge Marchant at
the Office of the Commissioners of Patents on the 26th April 1883.
ROBERT MUDGE MARCHANT of Fenchurch Street in the City of London [Civil
Engineer] " A METHOD
OR PROCESS FOR THE RETENTION AND CIRCULATION OF
STEAM IN ITS APPLICATION TO ENGINE POWER AND IN THE MEANS EMPLOYED
THEREFOR
"
1. My invention consists in re using the Steam so as to circulate a large portion
thereof as a repeated conduit for that heat which expresses the Engine power that
by such means I might with other advantages effect a great saving in that very
large proportion of the fuel which represents the cost of manufacture by such fuel's
necessary supply of that "latent heat" which is required for the construction of a
vapour out of a liquid and I now declare my process for effecting such action to
consist in my taking off a proportion of the Steam from the Cylinder of the Engine
as soon as it has done its full pressure work in such Cylinder to the purpose of my
returning that proportion of the Steam to the Boiler in the manner hereafter
described, and in my applying the remainder of the Steam to the purpose of obtaining
expansion and vacuum action to the Engine and of supplying by its condensation
that water of saturation to the Steam Pumps which enables me to repump the
Steam in the presence of its own liquid and to circulate the whole charge partly
as Steam and partly as water in the manner hereafter described
2. I so work the Engine under the favorable circumstances of both expansion
and vacuum and whilst doing this I apply the proportion of Steam taken off to
the pumps to the purpose of power in the barrel of the first pump and with the
result that the subsequent transmission of such Steam into the Boiler, as effected
Paine d

page_text: in the presence of its own liquid, absorbs so little power that I can carry a load
with the Engine when the pumps are in operation (and under the same circum-
stances of application in every other respect) that such Engine would not carry
without these pumps in operation.
3 The pumping of Steam in the presence of liquid of its own temperature
produces a mere "churning".action, as the vapour is alternately compressed into
its own liquids and again (with the return stroke) allowed to separate itself from
it-it therefore becomes necessary to obtain the boiler pressure in the pumps by
the introduction of a foreign element which shall act under that law of "Physics'
which teaches us that under a mixture of gases "the total pressure is equal to the
sum of the individual pressures" and that it by no means follows that each Gas
exercises the same pressure to the making up of such "sum or total pressure.
"1
"
4 My object has therefore been in accordance with this law, to add on to the
existing pressure of the Steam (in the pressure communicated to another and
foreign Gas) that further pressure which is required to make up the Boiler or
higher pressure, so that the whole charge of Steam with the required minimum of
such foreign element should go forward to the Boiler, and that a continuous circuit
of the Steam should be so effected. The conditions being-high pressure Steam and
temperature water of the same temperature and so much of a foreign vapour as is
necessary to supply the required difference or excess of pressure.
5 The "churning" and useless action, then becomes a forward and operative
action and the circuit is established by means of the pressure supplied to the
foreign element and added by it to the existing pressure of the Steam.
6 Air supplies a convenient foreign element for such process and its compression
is effected in the pumps, and the pressure so effected on a supplied minimum of
air, is so added on to the pressure of the Steam, as to effect under the law referred
to, the required pressure in the pumps to the attainment of the regular and
continuous circuit of the whole charge of Steam and water with a minimum of air
added to every forward delivery.
7 The air and the Steam retain their independent character, as distinct vapors,
and their separate action, the Steam entering its liquid without increasing its
pressure, and the air receiving the added pressure and communicating it to the
charge "the total pressure being the sum of the individual pressures
"
8 Endeavouring to account for experimental results, and at that time ignorant
of the Physical law referred to, I at one time concluded that the Air mixed with
the Steam and Water, but becoming aware of this law I discovered that throughout
the operation the air retains a seperate position being over the Steam and water,
and in such manner that when the outlet valves are at the bottom of the pump as
I now fix them, air remains in the pump clearances and gives back as a spring the
pressure communicated to it and such separate action of the gases can be ascertained
in the delivery pipe a "pet cock" on the top of which will give out any air in the
forward charge whilst a "pet cock" in the bottom of such pipe will give out highly
saturated Steam.
9 The pressure communicated to the air or other foreign element which is passed
forward with the Steam and water is not lost, for the portion returned in the
charge re-expresses such pressure to the purpose of power in the Cylinder of the
Engine with every renewed circuit of the returned charge and as the air remains
behind in the clearances of the pump, it acts as an air spring in the pump itself;
giving out on the returned stroke the pressure communicated to it for the delivery
stroke, and the excess passes forward with the charge of steam and water such
excess being limited to that necessary to complete the forward movement of the
Steam and water by a clean delivery.
94 Indeed perfect action would limit the supply of air to so small an excess
over that filling the duly proportioned clearances of the pump in its compressed
state after its propulsion of the charge that the air required would alternately be
compressed by external power and give out the same power on the return stroke
of the pump piston, so that the cost of transmitting the charge would be little

page_text: beyond the friction It would appear desirable to give an example of the action
effected, Assume a boiler pressure of One hundred and fifty pounds (150 lbs) and
steam into the first pump barrel at one hundred and twenty five pounds (125 lbs)
on the square inch and one third of the Steam taken off to the Boiler in the
manner stated. Then the steam into the barrel and pressing on the piston of the
first pump, will in the forward stroke do the work of one hundred and twenty five
pounds (125 lb) Steam according to its application, and having done this work it
will be compressed into liquid of its own temperature by the application of the
corresponding pressure of the One hundred and twenty five pounds (125 lb) plus
the fraction of one pound (1 lb) which is required to overcome its difference of
gravity at the one hundred and twenty five pounds (125 lb) pressure from the
water which receives it. The Air charge to be (at the end of the stroke) contained
in the pump, clearances being compressed to give under the physical law referred
to, and before attaining the clearance limit a little more than the twenty five pounds
(25 lb) of difference between the pressure of such steam charge and the boiler
pressure of "one hundred and fifty pounds (150 lb)" the total pressure being the
sum of the individual pressures
"
So that under the process the steam gives out to power in the pumps (less the
fraction of a pound for difference of gravity at the steam pressure) the same
pressure which has subsequently and on the return stroke to be put into it and the
air spring gives back in the pump and on the return stroke the same pressure
which had previously been put into it.
So that the power expressed by the Steam and the power expended on the air
in the pumps has to be re expressed in such way instead of any other and the
charge is as it were "swung back" to the Boiler-Whilst it effects in the high
pressure Cylinder a pure "caloric" action of one third of the Steam used in it, at
the full boiler pressure, and returns a feed of Steam in water, at approximately the
Boiler temperature or three hundred and fifty three degrees (353°) into three
hundred and sixty six degrees (366°).
But there is something more than this in such application so far as the power of
the Engine and work out of the Steam supplied to the pump is concerned. For
with one third of the steam so returned two pounds (2 lbs) of water at some One
hundred and forty degrees (140°) Fahrenheit would be supplied to one pound (1 lb)
of Steam on the compression side of the action and a condensation of some one
third of such steam charge to the pumps would then be effected on such com-
pression side in raising the temperature of the water to that of the steam, and
such one third of the full capacity for work of the charge of One hundred and
twenty five pounds (125 lbs) steam, would in the pumps be converted into
auxilliary power
The effect to be produced by such conservation and return of the "latent heat"
supplied by the fuel will be seen by the consideration that the best existing practice
requires the expenditure of twenty pounds (20 lbs) of Steam per H.P. per hour,
this represents at one hundred pounds (100 lbs) pressure 24, 230, beat units which
multiplied by the "equivalent" of Seven hundred and seventy two (772) foot
pounds for work units and divided by the 33,000 per Minute x 60 minutes which
is assumed as the H.P. unit. gives 9.44, H.P. or approximately that 10 H.P. by
pure "caloric" action which is generally spoken of as what would replace the
present attainment of 1. H.P. could such action be accomplished, To return all the
"latent heat" in the whole of the Steam (which cannot be done) would be to
attain such ten to one-and to return all the "latent heat" in one third of the
Steam would be to attain one third of such result and when it is considered what
benefit the addition of a vacuum of less than 14 lbs has effected on Steam
Engine practice there would appear little doubt that my experimental results
which prove such attainable economy will be generally realized.
ths
10. I will in the first place shew my process in connection with a special Engine
and Boiler for its superior application, and I will then shew it as applicable to
existing Engines for its inferior application,

page_text: 11. The point at which the Steam should be taken off to the pumps has been
proved by long continued and varied experiment to be the most important matter
for consideration and this should be effected in all cases, at that point where the
high pressure action in the Cylinder terminates and before the Steam is applied
to expansive action.
The advantages of applying in the first pump barrel the power remaining in the
Steam and of the comparatively small space (or pump) required for the reception
of a pound weight of such steam and of the high pressure temperature of the
whole feed (the temperature of which is always that of the steam supplied to the
pumps) afford a sufficient explanation of such proved desirability.'
12 I have indeed proved that rarified vacuum steam does not repay the labor of
such process the reason being the proportionately larger pumps to circulate the
same weight of steam (ie pressure to capacity of pump in inverse ratio) the
absence of working power in such steam which renders the operation a drag on
the Engine instead of the auxiliary action obtainable under the proper application
which means small pumps and powerful and therefore dense steam and a feed of
steam and water at nearly the Boiler temperature.
13 The proportion of the steam taken to the pumps for return to the Boiler as
Steam will be about two thirds of the whole of the quantity used to effect the
revolution of the Engine and the pumps will be so proportioned and set and
worked (stroke for stroke with the engine) in connection with the Engine Shaft
as to take any required proportion of the Steam at the point of such full pressure
delivery from the Cylinder of the Engine.
14 For my process in connection with a special Engine and Boiler for its superior
application I prefer a "tandum" Cylinder arrangement the smaller Cylinder or
Cylinders receiving throughout the stroke a full charge of steam at the Boiler
pressure and the larger Cylinder or Cylinders being about eight times the capacity
of the smaller Cylinder or Cylinders so as to make the return stroke to each
"tandum" application by means of the expansive force of its supplied proportion
of the steam previously used at full pressure in the smaller Cylinder it requires a
boiler capable of containing high pressure Steam and my British Patent of 1874
N° 509 shews one Boiler application capable of supplying steam over that pressure
of Three hundred pounds (300 lbs) on the square inch which I prefer for the
operation it requires a surface condenser and my British Patent of 1880 N° 374
shews a surface condenser capable of providing fifty feet of superficial surface to
one cubic foot of capacity, it requires pumps supplied with the necessary valves
and proportioned and set and worked as stated at (13 margin) and of the character
now shewn in preference to any of my former patented pumps and so constructed
that there shall be little clearance in the barrel of the first pump, and ample
clearances for the operation in the following stage or stages, it requires also an air
pump capable of freeing the surface condenser of any accumulation of the air which
separates itself from the vacuum steam supply on its condensation, and an arrange-
ment for giving the required minimum air or foreign gas supply to the steam
pumps the necessity for which has been already at 6 margin, it requires also a self
acting lift valve in connection with the Boiler through which the charge is delivered
without the possibility of back action from the Boiler. It requires that the
proportion of steam to be returned to the Boiler should be taken off to the Steam
pumps as soon as the effective stroke in the small Cylinder is completed the pump
being so set on the shaft as to receive such charge through the provided lift valve
attached to the pump and at the right moment, the remainder of the steam effecting
the return stroke by its expansion in the larger Cylinder and being assisted in
such action by the vacuum of the surface condensor and by the full pressure charge
so delivered into the barrel of the first pump, which charge propels the piston
therein expansively, for the remainder of its stroke (at least two thirds of the
whole) and it requires that the Steam doing the expressed work in the large
Cylinder shall after condensation in the surface condenser be delivered as water
into the first pump barrel at the time when on the return stroke of the piston

page_text: therein, the steam charge in it is being propelled into the following stage pump,
the first action of such steam under propulsion being such proportionate con-
densation as will raise such water to its own temperature, after which the action
becomes that of transmitting the Steam in presence of liquid of its own temperature
the whole charge being so transmitted by that compression of the air or foreign
medium which has been already described (at 6 margin) as effecting
pressure which is the sum of the individual pressure" ie. of the steam pressure
and of the foreign Gas or air pressure.
< a total
15 My process for application to existing Engines which although giving inferior
results to the above will yet effect very great economy requires to take the stated
proportion of the full pressure charge of Steam from the Cylinder at the point
where such full pressure charge has effected its work in the Cylinder, and before it
begins to expand therein, such proportion of Steam being taken off by self acting
lift valves fixed into the Cylinder at any point immediately before the expansive
action commences within the Cylinder (by the Action of the slide valve in cutting
off the steam supply) it requires that the steam should be delivered in the manner
already stated to pumps constructed, set and fixed as already stated for my superior
application-it requires that the exhaust from the Cylinder should be connected
with the surface condenser and that the whole of the provisions and arrangements'
except only in the manner of taking off the Steam from the Cylinder to the pumps
and in the use of an ordinary Boiler, should be as stated for my superior
application. The superiority of such action being chiefly consequent on the
inferior pressures obtainable from the ordinary Boiler construction and workable
with ordinary Cylinder and the slide valve action.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Robert Mudge Marchant in the Great Seal Patent Office on the
26th October 1883.
"
A
ROBERT MUDGE MARCHANT of Fenchurch Street in the City of London
METHOD OR PROCESS FOR THE RETENTION AND CIRCULATION OF STEAM IN ITS
APPLICATION TO ENGINE POWER AND IN THE MEANS EMPLOYED THEREFOR,"
.
- 1 My Invention consists in reusing the Steam so as to circulate a large portion
thereof as a repeated conduit for that heat which expresses the Engine power, that
by such means I might with other advantages effect a great saving in that very
large proportion of the fuel which represents the cost of manufacture by such fuels
necessary supply of that "latent heat" which is required for the construction of a
vapour out of a liquid and I now declare my process for effecting such action to
consist in my taking off a proportion of the Steam from the Cylinder of the Engine
as soon as it has done its full pressure work in such Cylinder to the purpose of iny
returning that proportion of the Steam, to the Boiler in the manner hereafter

page_text: described, and in my applying the remainder of the Steam to the purpose of
obtaining expansion and vacuum action to the Engine and of supplying by its
.condensation that water of saturation to the Steam pumps which enables me to
repump the Steam in the presence of its own liquid and to circulate the whole
charge partly as Steam and partly as water in the manner hereafter described
2 I so work the Engine under the favorable circumstances of expansion and
vacuum and whilst doing this I apply the proportion of Steam taken off to the
pumps to the purpose of power in the barrel of the first pump and with the result
that the subsequent transmission of such Steam into the Boiler as effected in the
presence of its own liquid absorbs so little power that I can carry a load with the
Engine when the pumps are in operation (and under the same circumstances of
application in every other respect) that such Engine would not carry without these
pumps in operation
3. The pumping of Steam in the presence of liquid of its own temperature
produces a mere "churning" action as the vapour is alternately compressed into
its own liquid and again (with the return stroke) allowed to separate itself from
it, it therefore becomes necessary to obtain the boiler pressure in the pumps by the
introduction of a foreign element which shall act under the law of "Physics
which teaches us that under a mixture of gases "the total pressure is equal to the
sum of individual pressures". and that it by no means follows that each Gas
exercises the same pressure to the making up of such
" sum or total pressure.
"
"
4 My object has therefore been in accordance with this law, to add on to the
.existing pressure of the Steam (in "the pressure communicated to another and
foreign Gas") that further pressure which, is required to make up the Boiler or
higher pressure, so that the whole charge of Steam with the required minimum of
such foreign element should go forward to the Boiler and that a continuous circuit
of the Steam should be so effected. The conditions being high pressure Steam and
temperature water of the same temperature and so much of a foreign vapour as is
necessary to supply the required difference or excess of pressure.
The "churning" and useless action then becomes a forward and operative action
and the circuit is established by means of the pressure supplied to the foreign
element and added by it to the existing pressure of the Steam
6 Air supplies a convenient foreign element for such process and its compression
is effected in the pumps and the pressure so effected on a supplied minimum of air
is so added on to the pressure of the Steam, as to effect under the law referred to,
the required pressure in the pumps to the attainment of the regular and continuous
circuit of the whole charge of Steam and water with a minimum of air added to
every forward delivery.
7 The Air and the Steam retain their independent character, as distinct vapors
and their separate action the Steam entering its liquid without increasing its
pressure and the air receiving the added pressure and communicating it to the
charge "the total pressure being the sum of the individual pressures"
8 Endeavouring to account for experimental results and at that time ignorant
of the Physical law referred to I at one time concluded that the air mixed with the
Steam and Water but becoming aware of this law I discovered that throughout
the operation the air retains a separate position being over the Steam and Water
and in such manner that when the outlet valves are at the bottom of the pump
as I now fix them, air remains in the pump clearances and gives back as a spring
the pressure communicated to it and such separate action of the Gases can be
ascertained in the delivery pipe a "pet cock" on the top of which will give out
any air in the forward charge whilst a " pet cock in the bottom of such pipe will
give out highly saturated steam.
9 The pressure communicated to the air or other foreign element which is passed
forward with the Steam and water is not lost, for the portion returned in the
charge re-expresses such pressure to the purpose of power in the Cylinder of the
Engine with every renewed circuit of the returned charge and as the air remains
behind in the clearances of the pump, it acts as an air spring in the pump itself,

page_text: giving out on the return stroke the pressure communicated to it for the delivery.
stroke and the excess passes forward with the charge of steam and water such
excess being limited to that necessary to complete the forward movement of the
steam and water by a clean delivery
94 Indeed perfect action would limit the supply of air to so small an excess
over that filling the duly proportioned clearances of the pump in its compressed:
state after its propulsion of the charge that the air required would alternately be.
compressed by external power and give out the same power on the return stroke
of the pump piston so that the cost of transmitting the charge would be little
beyond the friction. It would appear desirable to give an example of the action
effected. Assume a boiler pressure of One hundred and fifty pounds (150 lbs) and
Steam into the first pump barrel at one hundred and twenty five pounds (125 lbs)
on the square inch and one third of the Steam taken off to the Boiler in the
manner stated Then the steam into the barrel and pressing on the piston of the
first pump will in the forward stroke do the work of One hundred and twenty five.
pounds (125 lbs) Steam according to its application and having done this work it
will be compressed into liquid of its own temperature by the application of the
corresponding pressure of the One hundred and twenty five pounds (125 lbs) plus
the fraction of One pound (1 lb) which is required to overcome its difference of
gravity at the one hundred and twenty five pounds (125 lbs) pressure from the
water which receives it. The air charge to be (at the end of the stroke) contained
in the pump clearances being compressed to give under the Physical law referred
to, and before attaining the clearance limit a little more than the twenty five
pounds (25 lbs) of difference between the pressure of such Steam charge and the
boiler pressure of One hundred and fifty pounds (150 lbs) "the total pressure being
the sum of the individual pressures So that under the process the Steam gives
out to power in the pumps (less the fraction of a pound for difference of gravity
at the steam pressure) the same pressure which has subsequently and on the return
stroke to be put into it; and the air spring gives back in the pump and on the return
stroke the same pressure which had previously been put into it. So that the power
expressed by the Steam and the power expended on the air in the pumps has to be
re-expressed in such way instead of any other and the charge is as it were "swung
back" to the Boiler. Whilst it effects in the high pressure Cylinder a pure "coloric
action of one third of the Steam used in it at the full boiler pressure, and returns a
feed of steam in water at approximately the Boiler temperature or three hundred
and fifty three degrees (353°) into Three hundred and sixty six degrees (366°)
"
But there is something more than this in such application so far as the power of
the Engine and work out of the Steam supplied to the pump is concerned. For
with one third of the Steam so returned two pounds (2 lbs) of water at some One
hundred and forty degrees (140°) Fahrenheit would be supplied to one pound
(1 lb) of Steam on the compression side of the action and a condensation of some
one third of such steam charge to the pumps would then be effected on such.
compression side in raising the temperature of the water to that of the Steam and
such one third of the full capacity for work of the charge of One hundred and
twenty five pounds (125 lbs) Steam would in the pumps be converted into
auxilliary power.
The effect to be produced by such conservation and return of the "latent heat"
supplied by the fuel will be seen by the consideration that the best existing
practice requires the expenditure of twenty pounds (20 lbs) of Steam per H. P. per.
bour this represents at One hundred pounds (100 lbs) pressure 24-230, beat units
which multiplied by the "equivalent" of Seven hundred and seventy two (772)
foot pounds for work units and divided by the 33,000 per Minute × 60 minutes
which is assumed as the H. P. unit gives 9.44 H. P. or approximately that 10 H. P.
by pure "colaric" action which is generally spoken of as what would replace the
present attainment of 1 H. P. could such action be accomplished. To return all
the "latent heat" in the whole of the Steam (which cannot be done). would be to
attain such ten to one-and to return all the "latent heat" in one third of the

page_text: steam would be to attain one third of such result and when it is considered what
benefit the addition of a vacuum of less than 14/7/10 lbs has effected on Steam
Engine practice there would appear little doubt that my experimental results which
prove such attainable economy will be generally realized.
10 I will in the first place shew my process in connection with a Special Engine
and Boiler for its superior application and I will then shew it as applicable to
existing Engines for its inferior application.
11 The point at which the Steam should be taken off to the pumps has been
proved by long continued and varied experiments to be the most important matter
for consideration and this should be effected in all cases at that point where the
bigh pressure action in the Cylinder terminates and before the Steam is applied to
expansive action.
The advantages of applying in the first pump barrel the power remaining in the
Steam and of the comparatively small space (or pump) required for the reception
of a pound weight of such steam and of the high pressure temperature of the
whole feed (the temperature of which is always that of the. Steam supplied to the
pumps) afford a sufficient explanation of such proved desirability.
12. I have indeed proved that rarified vacuum steam does not repay the labor
of such process the reason being the proportionately larger pumps to circulate the
same weight of steam (ie capacity to pressure of pump in inverse ratio) the
absence of working power in such steam which renders the operation a drag on the
Engine instead of the auxiliary action obtainable under the proper application
which means small pumps and powerful and therefore dense steam and a feed of
Steam and water at nearly the Boiler temperature
13 The proportion of the Steam taken to the pumps for return to the Boiler as
steam will be about twothirds of the whole of the quantity. used to effect the
revolution of the Engine and the pumps will be so proportioned and set and
worked (Stroke for stroke with the Engine) in connection with the Engine shaft as
to take any required proportion of the Steam at the point of such full pressure
delivery from the Cylinder of the Engine
"
14 For my process in connection with a special Engine and Boiler for its
superior application I prefer a "tandum Cylinder arrangement the smaller
Cylinder or Cylinders receiving throughout the stroke a full charge of steam at
the boiler pressure and the larger Cylinder or Cylinders being about eight times
the capacity of the smaller Cylinder or Cylinders so as to make the return stroke
to each "tandum "application by means of the expansive force of its supplied
proportion of the Steam previously used at full pressure in the smaller Cylinder,
its requires a boiler capable of attaining high pressure steam and my British
Patent of 1874 N° 509 shews one Boiler application capable of supplying steam
over that pressure of Three hundred pounds (300 lbs) on the square inch which I
prefer for the operation, it requires a surface condenser and my British Patent of
1880 N° 374 shews a surface condenser capable of providing fifty feet of
superficial surface to one cubic foot of capacity, it requires pumps supplied with
the necessary valves and proportioned and set and worked as stated at (13 margin)
and of the character now shewn in preference to any of my former patented
pumps and so constructed that there shall be little clearance in the barrel of the
Hirst pump, and ample clearances for the operation in the following stage or stages,
it requires also an air pump capable of freeing the surface condenser of any
accumulation of the air which separates itself from the vacuum steam supply on
its condensation and an arrangement for giving the required minimum air or
foreign Gas supply to the Steam pumps the necessity for which bas been already
shewn at paragraph 6, it requires also a self acting lift valve in connection with
the boiler through which the charge is delivered without the possibility of back
action from the boiler.-It requires that the proportionate steam to be returned
to the boiler should be taken off to the Steam pumps as soon as the effective stroke
in the small Cylinder is completed the pump being so set on the shaft as to receive
such charge through the provided lift valve attached to the pump and at the right

page_text: moment the remainder of the steam effecting the return stroke by its expansion
in the larger Cylinder and being assisted in such action by the vacuum of the
surface condenser and by the full pressure charge so delivered into the barrel of
the first pump which charge projects the piston therein expansively for the
remainder of its stroke (at least two thirds of the whole) and it requires that the
Steam doing the expressed work in the large Cylinder shall after condensation in
the surface condenser be delivered as water into the first pump barrel at the time
when on the return stroke of the piston therein the Steam charge in it is being
propelled into the following stage pump the first action of such steam under
propulsion being such proportionate condensation as will raise such water to its.
own temperature after which the action becomes that of transmitting the steam
in presence of liquid of its own temperature the whole charge being so
transmitted by that compression of the air or foreign medium which has been
already described (at 6 margin) as effecting a total pressure which is the sum of
the individual pressures" ie. of the steam pressure and of the foreign Gas or air
pressure.
"
15 My process for application to existing Engines which although giving
inferior results to the above will yet effect very great economy requires to take the
stated proportion of the full pressure charge of steam from the Cylinder at the
point where such full pressure charge has effected its work in the Cylinder and
before it begins to expand therein such proportion of steam being taken off by
self acting lift valves fixed into the Cylinder at any point immediately before the
expansive action commences within the Cylinder (by the action of the slide valve
in cutting off the steam supply) it requires that the steam should be delivered in
the manner already stated to pumps constructed set and fixed as already stated for
my superior application-it requires that the exhaust from the Cylinder should be
connected with the surface condenser and that the whole of the provisions and
arrangements except only in the manner of taking off the Steam from the Cylinder
to the pumps and in the use of an ordinary boiler should be as stated for my
superior application. The superiority of such action being chiefly consequent on
the inferior pressures obtainable from the ordinary Boiler construction and workable
with ordinary Cylinders and the slide valve action
In order that the Invention may be well understood and explained in detail I
have hereunto annexed 2 Sheets of Drawings on which letters of reference are
monlod o Conding norte on all the Finaalike
Fig 1. represents a plan view of the apparatus shewing the general arrangement
of the parts comprising the means for carrying out my process for the retention
and circulation of Steam, Fig 2 represents a longitudinal section of the tandum
Cylinders and arrangement of valves
Fig 3 represents the longitudinal section of an ordinary Cylinder for what I term
my inferior application
Fig 4 represents a section of one of the first steam pumps and,
Fig 5 represents a section of the last steam pump.
In these Figs A is the small cylinder of the tandum pair A' is the larger Cylinder
of the tandum pair B is the boiler or steam Generator and C is a surface condenser D,
is the first pump and D' the second or last pump, D² the air pump E is a self acting
lift valve provided with a stop a, a. is the pipe taking off the steam to the pumps
as soon as the effective stroke in the small tandum Cylinder A is completed the
pump D being so set as to receive the charge b is the pipe delivering the remainder
of the steam charge to the large Cylinder of the tandum pair A¹ The steam after
its expansion in the large Cylinder A' is delivered or passed through the pipe c to
the surface condenser Ŏ from this condenser the charge of Steam so received is
condensed and the water of condensation is passed through the pipe d for the

page_text: purpose of transmission from the pump D' through the pipe e. e. and valve f to the
first pump D.-There being one delivery of Steam from the high pressure tandum
Cylinder A to the pump D with every revolution of the Engine one side only of
the piston of that pump is applicable to the operation and compression of every
charge of Steam and in the case of a single pair of tandum Cylinders the opposite
side of that piston is operated as an air pump sucking the air through the valve g
and valve h from the Condenser C and ejecting it into the atmosphere through the
valve The charge of Steam under compression as the pump D is passed through
the valve and pipe m into the last pump D¹ seen more clearly at Fig 5 with the
water and air supplied from the pump D' and from the pump D' this mixture is
passed through the pipe n and valve o into the barrel on the reverse side of the
piston in the pump Di from whence it is ejected through the valve p and pipe q
into an air chamber r placed above the pump D' from whence through the pipe s
and valve E this mixture is delivered into the Boiler B when after receiving its
dose of heat it repasses through the pipe t and open stop cock u into the small
Cylinder of the tandum pair A.
In carrying out my inferior process as applied to existing Engines I take off the
required proportion of the full pressure of steam from the Cylinder as shewn in
Fig: 3 at the valves v. v. which are fixed in the positions when any charge has
effected its full pressure action in the Cylinder and before it begins to expand
therein, from these valves v. v. I deliver in the manner already stated to pumps D
and D¹ and I take the exhaust steam from the Cylinder at the end of the stroke
and connect it in the manner already stated with the surface condenser C after
which the process goes on as previously described ww are suction and force
valves.
Having now described the nature of my said Invention together with the means
I employ for carrying the same into practical effect I wish it to be understood in
conclusion that what I claim as new and as of my Invention is
The combination of the parts for carrying out my process for the retention and
circulation of Steam to be employed in the manner and for the purpose as herein
substantially described set forth and illustrated in the drawings annexed
In witness whereof I the said Robert Mudge Marchant have hereunto set
my hand and seal this Twenty fourth day of October in the year of our Lord
One thousand eight hundred and eighty three.
Witness:
THOMAS WRIGLEY
75 Chancery Lane
London W.C
RM MARCHANT (LAS.) 3