IMPROVEMENTS IN MOTIVE-POWER ENGINES AND IN APPARATUS CONNECTED THEREWITH.
Year: 1874

page_text: LETTERS PATENT to Robert Mudge Marchant, of Kirby Street, Hatton
Garden, in the County of Middlesex, Civil Engineer, for the
Invention of "IMPROVEMENTS IN MOTIVE-POWER ENGINES AND IN APPARATUS
CONNECTED THEREWITH.
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Sealed the 9th April 1874, and dated the 9th February 1874.
PROVISIONAL SPECIFICATION left by the said Robert Mudge Marchant
at the Office of the Commissioners of Patents, with his Petition,
on the 9th February 1874.
I, ROBERT MUDGE MARCHANT, of Kirby Street, Hatton Garden, in
the County of Middlesex, Civil Engineer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN MOTIVE-POWER ENGINES AND
IN APPARATUS CONNECTED THEREWITH," to be as follows:-
My Invention consists in the special application and use of a com-
bination of air, steam, and caloric as a motive power, such combination
being applied to such purpose in continuous circuit of the already heated
medium, and in such manner that the caloric lost during the expansion

page_text: of the heated air and steam in its application to effected power, either in
any cylinder or other mechanical contrivance for effecting and trans-
mitting the power shall be restored to it again during its passage as air
and steam through tubes in a heater or boiler so constructed as to
facilitate its transit and the absorption by it of the heat, which is com-
municated by the fire contained therein, after which operation it is
continually reused in the cylinder or other effecter and transmitter of
that power which is represented by the working pressure contained in
such combination.
"
In a former Invention, for which Letters Patent were granted to me
dated the 13th April 1870, No. 1086, I provided an economical system of
pumping any gas or combination of gases in stages of compression; and
in another Invention for which Letters Patent were granted to me dated
the 25th July 1871, No. 1949, I provided a regulator to facilitate the
operation of repumping any once used and heated exhaust. Long
continued and costly experiment has since led me to the perfection of
the application in the use of a combination of air, steam, and caloric as
a motive power, the air and steam being made the medium of continuing
the circulation of all for continuous use through a heater or boiler, in
which the caloric which has been expended is renewed for every sub-
sequent operation. I therefore desire to name the perfected engine "the
combined air, steam, and caloric engine." It provides for the use of air,
steam, and caloric in continuous circuit in such manner that the whole
of such combination in the "exhaust or any portion thereof is re-
pumped to the required pressure and delivered at the working pressure
into the heater or boiler after each several application of these gases to
the purpose of power, the caloric being restored to these gases in the
heater or boiler, through which they are so repassed for each and every
subsequent use. In this operation the "exhaust" side of the piston in
the cylinder is used as the first alternating pump, and other pumps are
used in connection therewith and worked under stages of compression,
the last pump delivering the gases into the heater or boiler at the
working pressure of the engine, and the density of atmosphere from
which it pumps to such pressure is that with which it is supplied from
the already effected pressure of the preceding pump, all the pumps
working in a similar manner, and so that the pressure attained by each
preceding pump becomes the starting point for the further compression
to be effected by the pump that is next in rotation.

page_text: 5th. Of a joint for connecting the small pipes inserted into the external
horizontal pipes with the small pipes inserted into the closed end of each
vertical tube, such joint allowing such connection to be formed securely
and with ease in its provision for any irregularity in the length of the
small pipes, which without such provision would have to be all of exactly
equal length, and I prefer making such joint of a brass connecting pipe
so as to obviate any necessity for copper rings between the back nuts
and such connecting ning

page_text: 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 8th August 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
MUDGE MARCHANT, of Kirby Street, Hatton Garden, in the County of
Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of February, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Robert Mudge Marchant, Her special
licence that I, the said Robert Mudge Marchant, my executors,
administrators, and assigns, or such others as I, the said Robert
Mudge Marchant, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time, and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN MOTIVE-POWER ENGINES AND IN APPARATUS CONNECTED
THERE WITH," upon the condition (amongst others) that I, the said Robert
Mudge Marchant, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Robert Mudge Marchant, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, reference being had to the accom-
panying Drawings, that is to say:-
My Invention consists in the special application and use in com-
bination of air, steam, and caloric for the purpose of generating or de-
veloping motive power in the manner herein-after particularly described.
In a former Invention for which Letters Patent were granted to me,
dated the 13th April 1870, No. 1086, I provided an economical system

page_text: of pumping any gas or combination of gases in stages of compression,
and described the manner of working the same and apparatus used
therein; and in another Invention for which Letters Patent were granted
to me, dated the 25th July 1871, No. 1949, I provided a regulator to
facilitate the operation of repumping any once used and heated exhaust
and other apparatus employed in working the said Invention. Long
continued and costly experiments have since led me to the perfection of
the application and use in combination of air, steam, and caloric for the
purpose of generating and developing motive power, the air and steam
being made the medium of continuing the circulation of all for con-
tinuous use through a boiler or heater, in which the caloric which has
been expended is renewed or recovered for every subsequent operation.
In constructing what I term my "air, steam, and caloric engine,” I
apply the pressure which I prepare and perfect in a boiler or heater (of
the character herein-after described and shewn in the annexed Drawings)
for the purpose of communicating motion to the pistons of a cylinder or
cylinders (of the character shewn in the said Drawings) by the action of
two valves, one of which in the manner herein-after described delivers
the full pressure steam at one end of the stroke and provides for its
expansive application at the other end of the stroke, and the other of
which alternately opens and shuts at the end of each stroke the com-
munication between the expanded steam and the exhaust regulator.
I provide an exhaust regulator (of similar character to that herein-after
described and shewn in the Drawings) in which I retain approximately
that amount of pressure to which the cylinder arrangements would
expand the steam, and when the accumulation of the exhaust steam in
the regulator raises the pressure in the regulator above that due to its
working expansion I reduce such pressure where the operation is not
attended with inconvenience by condensation in the regulator so as to
retain and circulate the original charge of the engine without necessity
for additional water supply; but where such operation is inconvenient
and the retention of all the water in the engine is of little moment I
allow the surplus to escape, and supply to the regulator itself the
quantity of water which such escape represents, so that any deposit from
such supply shall occur in the regulator only, which can be easily
cleaned, and all that passes forward from it through the pumps to the
boiler shall be of the character of water obtained from condensed
steam.

page_text: I provide and work pumps in stages of compression (such pumps
being advantageously made of the character herein-after described and
shewn in the Drawings), and through such pumps I circulate and re-
compress the exhaust, saturating it with water of the temperature due
to its stage of compression, and from the last pump of the series I pass
the saturated vapor forward to the boiler at the full working pressure
in the manner herein-after described and shewn in the Drawings. The
action of these pumps on an elastic material necessarily expresses in
vaporised water from the pumps that added temperature for each opera-
tion which is due to the effected compression, and such vapor is
necessarily retained within the engine as part of the operation which is
effected by the work of the pumps.
I provide a boiler of the character herein-after described and shewn
in the Drawings, and in it I complete the operation by the evaporation
of that saturation which is given to the exhaust during its compressed
circulation in return through the pumps to the boiler. The amount of
such saturation decreases with the velocity of the engine, but may with
advantage be so regulated as not to exceed 1 of water to 30 of exhaust
steam.
The foregoing description explains in a general manner the construc-
tion and continuous operation of the engine and the means by which I
circulate any determined proportion of the exhaust steam within it, as
also the means by which I circulate as water that portion of the exhaust
which I do not circulate as steam, so circulating it in order to saturate
30 in volume and upwards of the steam portion thereof with 1 in volume
of water.
I now proceed to describe in a more particular manner the con-
struction of the various portions of the engine, and as the boiler is the
originator and maintainer of the whole action of the engine I will
describe its construction first.
The boiler or heater consists of horizonal or approximately horizontal
tubes which are fixed over the fire, and which for convenience of con-
struction I prefer to be of the shape known as the D tube, and which
can be stayed in the manner shewn in the Drawings, or as otherwise
required. Any required number of these D tubes can be connected
together by pipes in the manner shewn in the Drawings, so that the
water shall have free passage from one to the other by means of a

page_text: connecting horizontal pipe, which can be used as a blow-off pipe to them
all whenever such operation is considered desirable or necessary. Into
one or more of these D tubes I deliver by means of a perforated pipe the
saturated and compressed exhaust from the pump or last of a series of
pumps, and in such manner that a forcing circulation is maintained
throughout the whole of the tubular portion of the boiler or heater.
Into the upper surface of these D tubes I attach either by screwing in
or by means of an intervening nipple vertical pipes of small diameter,
and of any determined number and height, and by the insertion in the
upper end of each of these of a smaller pipe, and by the connection of
all such smaller pipes with horizontal pipes of much larger diameter at
the top of the heater, I continue in the manner shewn in the Drawings
the circulation through the whole of the pipes into that pipe which
reconveys the steam into the cylinder for its further application to
effective power. I find that these horizontal pipe connections may with
advantage be made of special short malleable cast iron or brass pipes,
and in the manner shewn, for the purpose of lessening the number of
joints, and of simplifying their construction, the necessity for copper
washers or other contrivances for making a tight joint for high pressure
being thus avoided. In this boiler or heater I place all the vertical
tubes in a combustion chamber immediately over the fire, and in such
combustion chamber I confine the whole of the heating surface in the
manner shewn in the Drawings, and from the bottom only of the com-
bustion chamber I form a connection with the chimney, by which
means I confine all the available heat obtainable from the products of
combustion in the chamber itself, and having extracted this give it the
most direct delivery into the external atmosphere that is obtainable.
The cylinder or cylinders I construct in the manner shewn in the
Drawings, although they may be of any other suitable construction. As
shewn, the small cylinder works under the full pressure steam, and the
large cylinder works the return stroke under the expansion of that full
pressure charge which has already acted on the piston of the small
cylinder. The space between the small and large pistons is kept always
in connection with the exhaust steam, and consequently in an atmosphere
of that density by means of the open passage between the exhaust and
the bottom of the large cylinder, and by such provision the proportionate
resistance offered by the exhaust does not exceed that which would be
due to effecting the whole of the expansion in one continuous cylinder.

page_text: With regard to the cylinder valves I find it advantageous to effect the
delivery and expansion of the high-pressure steam with one piston valve
only, and to obtain the required change in its action at the time of most
rapid travel of the valve. This valve is made to operate for the full
pressure delivery at one end of the valve, and for the expansion delivery
at the other end of the valve, and the rapid travel obtained by the
required set of the eccentrics on the shaft prevents the throttling action
due to the slow travel of any inferior set of the eccentric at the moment
of supply or cut off. This arrangement of valves I connect with the
action of one piston valve, also for the exhaust, which valve also opens
at its most rapid point of travel for the high-pressure stroke, and closes
at its most rapid point of travel for the stroke due to the expansive
action of the original charge.
As it occurs in practice that the piston valve against which the full
pressure steam has free and constant access is enveloped in and as it
were embraced by the steam, and that the spring rings are so compressed
by its action as to cause great leakage, and as with an arrangement such
as has been described, and with one valve only, no provision of metal or
workmanship appears capable of obviating this very great disadvantage
and loss of power which is consequent on such leakage of steam into
the wrong end of the cylinder, and considering that at lbs. 500 pressure
a valve which is only ono-and-a-quarter inch diameter and three-quarters
of an inch in depth would be in the grip of nearly fifteen hundred
pounds of steam, the difficulty of avoiding such leakage with any spring
application and one valve only becomes evident. The spring being once
embraced by the steam, which has free access to the bottom of the piston
valve spring, the leakage becomes constant, and I therefore employ an
additional valve, with the object of rendering such access of the steam
to the operating valve of such an intermittent character as shall not give
time for such action on its spring rings, that is to say, shall not give the
steam time so to embrace and compress the valve. With that object I
place the other or additional valve between the operating valve and the
full pressure supply, which valve cuts off the full pressure from the
operating valve during one-half of every revolution of the engine. And
with the further object of preventing leakage into the wrong end of the
cylinder during that portion of the revolution in which the operating
valve is exposed to the full pressure charge I place a similar additional
yalve forward of the operating valve and in the expansion delivery.

page_text: The steam can be admitted within the springs of both these addi-
tional valves, and I prefer to do so as a means of keeping the springs
up to their work. The additional valves are worked from the same
excentric and connecting rod as the operating valve.
The exhaust regulator consists of a tank or reservoir, which I find it
advantageous to make of a circular form, to which tank the exhaust
from the cylinder has equally free access to that which is given such
exhaust to the first pump of any series. This tank therefore receives
that surplus of the exhaust which is not pumped forward in circuit to
the boiler, and when the accumulation of such surplus raises the pressure
in the tank above that due to the expansive action of the steam in the
cylinder, condensation is effected in the tank by the circulation of water
through pipes which are made to traverse it for the purpose. The
amount of such condensation can be easily regulated by a cock, which
determines the water flow through these pipes.
The general character of the construction of the exhaust regulator is
shewn in the Drawings, and the surplus of the exhaust steam that is so
condensed in the regulator is pumped forward as water saturation to the
steam which is in circuit through the pumps to the boiler in such
manner that condensation is effected to the extent of the saturation
required.
The pumps I construct as shewn in the Drawings of two double-
acting pumps, which compress the exhaust to the full working pressure
in four proportionate stages. They consist of the pump chambers and
barrels, and of the plungers which work in them, the size of the rods of
each plunger regulating the compression effected by the preceding stage,
in which there is no rod to reduce that capacity which is represented by
the size and stroke of the plunger. When the engine is running these
four chambers are alternately full of water of very high temperature and
of the saturated charge, which is admitted over such water on the return
stroke for its propulsion in the forward stroke.
On these pump chambers is fixed the valve plate, which contains the
required passages, and two valves for each of the four stages in these
passages, that is to say, the valve which admits the charge, and the one
through which the charge is forced onwards. On the valve plate are a
fixed the four storage chambers, one for each stage of pumping, the
whole being bolted together in the manner shewn in the Drawings. The

page_text: excentrics by which these pumps are worked are set at right angles to
each other, and the work becomes so distributed round the whole of the
engine shaft as to give a very approximately uniform resistance. These
pumps are provided with air valves, through which air can be taken into
the engine when it appears desirable to do so.
The foregoing description of the heater or boiler of the cylinders and
valves of the exhaust regulator and of the pumps will be more clearly
understood by reference to the Drawings, which explain and illustrate
the connection of the various parts of the whole engine.
Such arrangement and connections may in some cases be varied
according to circumstances; the cylinders may be placed in any position,
and the pumps may be worked by gearing from the shaft so as to allow
of very small pumps being used and to give them great and proportionate
velocity of travel, but in all cases the parts will consist of the boiler or
heater, a cylinder or cylinders of the character shewn, or of some other
known means of applying pressure to the attainment of motive power
of an exhaust regulator or partial condenser, and of a pump or pumps
applicable to the compression, saturation, and transmission to the boiler.
of the heated exhaust.
In Sheet I. Figure 1 is a back elevation, with the boiler removed, and
Figure 2 a side elevation, representing an air, steam, and caloric engine
constructed according to my Invention. In Sheet II. Figure 3 is a
front elevation, and Figure 4 a plan of the same, both partly in section.
In Sheet III. Figures 5 and 6 are vertical sections taken at right angles
to each other, and Figure 7 a horizontal section of the boiler. A is the
boiler or heater; a, the furnace or fire-place; a¹, the horizontal tubes of
the boiler; a³, the connecting and blow-off pipe; a³, the perforated or
delivery of charge pipes; a', the vertical pipes connected with the
horizontal pipes a¹ by means of intervening nipples; a³ are smaller pipes
connecting the upper ends of the pipes at with depending or trough
portions at of horizontal malleable, cast-iron, or brass pipes a°; a' is the
pipe for reconveying the steam to the cylinder; a³ is the combustion
chamber; a is the passage to the chimney from the bottom of the
combustion chamber. B represents the cylinder or cylinders; b, the
open passage for exhaust between the pistons; c is the operating valve;
c', the exhaust valve; d is a valve between the operating and the
full pressure supply; and d³, a valve in the expansion delivery; these

page_text: valves d and d¹ being the additional valves herein-before described for
the prevention of leakage. E is the exhaust regulator, and e the
traversing pipes. F represents the pumps; f, the pump chambers and
barrels, the valve plate; f2, the storage chambers; f³, the air and
exhaust valves; and f*, the saturated feed supply.
And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that I claim as my
"Improvements in Motive Power Engines and in Apparatus connected
therewith,"
1st. The combination of parts hercin-before described and represented
in the accompanying Drawings, and constituting what I term my "air,
steam, and caloric engine."
2nd. Constructing engines such as are herein referred to, so that the
heated exhaust or any portion thereof as returned in the state of
saturated vapor to a boiler or heater may be further heated and subse-
quently utilized, substantially as herein-before described.
3rd. Constructing engines, such as are herein referred to, so that any
portion of the condensed exhaust in its condition of boiling water may
be utilized to saturate the rest of the exhaust in the state of vapor
during its return passage through forcing pumps to the boiler, substan-
tially as herein-before described.
4th. Constructing and employing pumps, substantially in the manner
and for the purpose herein-before described.
5th. The construction and use of a central valve plate between the
pumps and storage chambers, substantially as herein-before described.
6th. The combination of parts forming my improved heating apparatus
in which all the heating surface is placed in a combustion chamber, from
which the products of combustion are delivered to the chimney fluc, and
from the bottom thereof in the manner and for the purpose substantially
as herein-before described.
7th. The arrangement of parts by which one operating piston valve is
made to act both for the full charge and for the expansive action,
substantially as herein-before described.
8th. The employment or provision of an additional valve between the
full pressure and the operating valve, and of an additional valve in the 3

page_text: expansion delivery, substantially as and for the purpose herein-before
described.
In witness whereof, I, the said Robert Mudge Marchant, have
hereunto set my hand and seal, this Sixth day of August, One
thousand eight hundred and seventy-four.
Witness,
J. C. MEWBURN,
Patent Agent,
169, Fleet Strect,
London.
R. M. MARCHANT. (L.S.)