AN IMPROVED COMBINED FURNACE AND STEAM ENGINE
Year: 1882

page_text: LETTERS PATENT to Virgil Warren Blanchard, of the City and State of New
York, United States of America, Doctor of Medicine, for an Invention of
"AN IMPROVED COMBINED FURNACE AND STEAM ENGINE"
COMPLETE SPECIFICATION filed by the said Virgil Warren Blanchard at
the Office of the Commissioners of Patents on the 30th November 1882.
VIRGIL WARREN BLANCHARD, of the City and State of New York, United
States of America, Doctor of Medicine, AN IMPROVED COMBINED FURNACE AND
STEAM ENGINE"
ES
Figure 1. is a side view of my invention partly in section. Figure 2, is a section
through the water reservoir Cu showing the alarm mechanism and Figures 3. 4.
and 5 are detail views of the liquid distributors. The first part of my invention
relates to Hydrocarbon Furnaces, and an apparatus for the production of steam,
and for other purposes, and it consists: First in an improved furnace for general
purposes in the Arts and which is designed for burning ordinary fuel such for
instance as wood, anthracite or bituminous coal; or for burning liquid or pulverized
fuel separately or singly; in each instance realizing from the fuel which it is
found desirable to use the most desirable results in the process of its combustion.
The second part of my invention consists in a combined air heater and distributor
of novel construction, that may be applied to the fire or fuel chamber of any
furnace by means of which a more perfect combustion of the fuel burned on the
grate bars or dispersed above them, obtained, than would be possible if it was
burned by the method now in usual practice. Third, in a combined air heater
and steam condenser that serves as a valuable auxiliary to the combined air heater
and distributor within the furnace in serving both to heat and to promote the
process of combustion within the furnace and to utilize the exhaust steam by
condensing it back to water. Fourth, in an air heater of novel construction adapted
for use in connection with the aforesaid combined air heater and steam condenser
and with or without the air heater within the furnace for the purpose of a more
perfect utilization of the waste gases that usually pass off through the escape flue

page_text: of the furnaces hitherto constructed. Fifth, in a receptacle for the water resulting
- from the condensation of the exhaust steam from the cylinder of the engine, which
is so applied as to afford a suitable reservoir to the water of condensation from the
combined air heater and steam condenser previous to its being returned by a pump
to the boiler. Sixth, in a water heater of novel construction forming a part of the
steam boiler and so applied that when it is used in combination with a pump, and
the combined air heater and steam condenser it will return the water of con-
densation to the boiler at a very high temperature. Seventh, in a novel device for
effecting the evaporization or distillation of water by means of the heat contained
in the exhaust steam; by means of which water may be freed from impurities
before it is supplied to the boiler to compensate for the waste consequent to
leakage and also the water resulting from the motion of the piston in the cylinder
of the engine. Eighth, in a device by means of which steam as well as air may
be introduced into the blast, by which combustion is carried on within the furnace.
Ninth, in a novel arrangement of parts by which the water of condensation from
the exhaust steam is returned to the boiler at a temperature a little below the
heat of the exhaust steam as it leaves the cylinder of the engine. Tenth, in such
arragement of an air pump with connecting pipes and valves therefor that the
volume of air may be measured previous to its being discharged into the fuel and
combustion chamber of the furnace to carry on and make complete the process of
combustion in the same. Eleventh, in a combustion of elements whereby a partial
vacuum is formed behind the piston of the steam engine, thereby obviating the
loss of power consequent on its working against the pressure of the atmosphere.
Twelfth, in a novel device applied to the reservoir holding the water derived from
the condensation of the exhaust steam, and the steam of evaporation; so that
a failure of the part of the pump to return the water of condensation back to the
boiler will cause an alarm to be sounded thus warning the attendant of danger,
and preventing the explosion of the boiler in consequence of low water that
attends the usual method as will be hereinafter explained. A designates an
ordinary tubular boiler of the upright kind, and of the ordinary and usual con-
struction. The heating flues occupy the upper portion of this boiler. Below the
flues the water space is seen in figure 1. with the aperture for the furnace door
which opens into the fire box; also the aperture for the door opening into the
asb pit. The grate bars are not shown they being just below the fire box aperture.
F, designates the steam chest and F1 the vertical cylinder thereof, the governor
being arranged above the cylinder and crank, the fly wheel and its connections
being arranged below the cylinder. These parts.need no detailed description as
they are so well known although they take part incidentally in my invention.
The letter D designates a secondary steam-chest and cylinder receiving live (or
common) steam from the boiler A by means of the pipe M¹ and exhausting
the same from the cylinder D" by means of the pipe D into the pipe G. The
office of this engine is to give motion simultaneously to the air pump D' and the
water pump L. It will be observed that motion is communicated from one
end of the piston-rod of the air-pump D', to the piston rod of the water pump L
by means of the arm J. Both the air pump D and the water pump L are
similar to those in general use, therefore do not require a
more detailed
description; the office of the former being to supply the furnace of the boiler A
with air or air and steam to carry on the process of combustion of the
fuel within the same after such gaseous elements have performed other
offices which will be. hereinafter described; and the office of the latter
to return heated water to the boiler A in the manner also hereinafter
specified. B designates a cylindrical air heater above the boiler A. It will be
observed by reference to the drawings that the said air heater is closed at
both ends and that it is supplied with a large number, of upright pipes or flues a
extending its entire length. These pipes or flues a afford a passage for the water
gases from the top of the furnace with which they communicate, to a suitable con-
ductor that may be adjusted to the upper portion of the air-heater B to carry the

page_text: same away. The air heater B, is a closed vessel and is divided by horizontal
diaphragins or partitions b, into compartments which communicate with each other
zigzagging by a portion of the partitions being omitted alternately, so that air or
gases being introduced under pressure into the lower compartment will pass across
the same and rise into the compartment next above and thus take a tortuous or
serpentine course through the heater B, as indicated by the arrows.
I thus expose
said gaseous elements to the effects of the heat resulting from the passage of the
waste heated gases through the upright pipes or flues a in the most effectual
manner to receive or eliminate heat from the same. It will thus be seen that with
a brisk fire in the boiler furnace, the heated air or other gaseous elements intro-
duced through the pipes R, under pressure, into the lowest compartment of the air
heater B, will be compelled to pass to and fro in a transverse direction across said air
heater as many times as there are horizontal partitions or diaphragms b, and will
during the passage thereof become heated by the upright pipes or flues a previous
to its passage from said heater through the pipe K. It will be clearly seen that
my manner of constructing the air heater B serves in a high degree to transmit the
heat of the waste gases passing from the top of the boiler A to the gaseous
elements passing under pressure through the interior of said air-heater in the
manner heretofore set forth. C designates a cylindrical vessel composed of a series
of concentric tubes d, with closed extremities, the annular spaces between said
tubes & communicate with each other in the manner hereinafter explained. The
object of this vessel C is three-fold viz: first to heat the air supplied by the air
pump D¹ previous to its entering the air heater B; second to condense the exhaust
steam coming from the steam-chest F, of the engine and the engine D" back to
water previous to its being returned to the boiler A, by the pump L; and third to
serve if desired as a water heater to heat water to supply the waste resulting from
a greater or less loss from running the engine (whose valve box F) and also the
engine D". It will be seen that the annular spaces between the tubes, composing
the vessel C, have a certain regular connection with each other, such space between
two tubes connecting at their closed extremities by a tube c, with a space, so as
that two distinct channels are formed through the vessel C, independent of each
other, by the thickness of the metal forming the walls of the concentric tube that
take part in the formation of the vessel aforesaid. Hence, if at the same time the
exhaust steam from the engine F' and D" is. introduced by a pipe into the interior
cavity of the vessel C, and cold air is introduced under suitable pressure by a pipe
communicating from the air pump D' with the smaller space between the inner
tube and the one that surrounds it, it will be seen that the steam and the air will
traverse separate channels formed by the space between the concentric tubes in the
vessel C, and their connecting pipes being separated only by the thickness of the
metal out of which the walls of the said tubes are formed. It therefore follows if
the vessel is of ample size that if a sufficient volume of cold air &c so introduced
into it simultaneously with the exhaust steam, in the manner just described, the
heat of the exhaust steam will be imparted to the current of air, separated from it
by a metallic wall only, sufficient to cause a condensation of the said steam to
water at or near the boiling point, while at the same time the current of air by
which the condensation of the steam is produced, is heated to a greater or less
degree of intensity according to its volume, and the pressure used in its trans-
mission. It will be observed that the annular spaces in the vessel C, which
constitute the steam channels in the same as so connected with each other by tubes
as to form a descending passage, so that the water of condensation will flow by its
own weight from said vessel through the pipe C' which connects outwardly with
said steam channels. This is a very important feature of my invention. By the
introduction of a stream of cold water into said channels traversed by the steam in
the combined steam condenser and air heater C, it is evident that less air would be
required to condense the steam to water in the manner described, while at the same
time the water thus introduced would become heated to a temperature the same or
nearly the same as the exhaust steam within said vessel, Thus the vessel C would

page_text: pass
serve at the same time as a water heater and an apparatus for condensing exhaust
steam to water by means of cold water and cold air mingled in suitable proportions.
G' designates a pipe for conveying the exhaust steam from the cylinder of the
engine F¹ to the vessel C. It will be observed that in close proximity to the engine
cylinder, the pipe G¹, is expanded into a vessel S so as to allow another pipe Gii to
in a serpentine direction through it; and also beyond this vessel it is expanded
in diameter so as to allow the pipe G" to pass inside of it leaving sufficient space
between the two pipes to allow a free passage of the exhaust steam, from the
chest F, of the engine through a part of its journey to vessel C. It will also be
observed that at a certain point the pipe Gu passes out of the pipe G¹, after which
the pipe G in a diminished size after entering and leaving, the vessel G com-
municates with the interior of the vessel C. It will also be seen that the pipe G"
enters the boiler A, and that its interior is continuous with the steam space of the
boiler to the point where said pipe is connected with the pump L near the check
valve L of the latter; so that the steam pressure in the boiler extends through
pipe G to this check valve. The two pipes G₁, and G" together form a water
heater which when it is taken in connection with the boiler A, the vessel C, and
the pump L, form an element of the greatest importance whose function will be
hereinafter set forth. C¹ designates a pipe connecting with the steam channels in
vessel C, and the reservoir C and it will be seen that a continuation of this
pipe C¹ also connects the reservoir C, and the pump L, so that a stream of water
will pass by its own gravity from the steam channels of vessel C, to the pump L
passing through the reservoir C". This reservoir C₁, performs two very important
offices viz: first to afford a reservoir to contain the water of condensation from the
vessel C and prevent the steam passage in this vessel from being filled or flooded
with water in case of any derangement in the working of the pump L; and second
to serve as an element in an automatic alarm in case of a derangement in the
working of the pump L; thereby calling assistance to repair the difficulty. This
reservoir C is provided with an ordinary water gauge so that the engineer may
at a glance determine the depth of water in it. This reservoir C should be of
sufficient size to hold for a considerable period of time the water of condensation
as it flows from the vessel C, in the manner above described so that in the event
of any derangement of the pump L, the vessel C, may not be in danger of being
flooded with water, which should be conveyed into the boiler A as fast as it
accumulates at the inlet valve L' of said pump by the action of the latter. The
letter U (see figure 2) represents a hollow metallic float located inside of the
reservoir C. This float is provided with a stem U which passes through the top
wall of the reservoir. The float U, being of thin metal and provided with a closed
cavity filled with air will always float on the surface of the water in the
reservoir C when the water accumulates in the latter, so as to rise above the
upper third; V represents a coiled spring attached to an arm of a rotary steam
valve in a pipe connected with the boiler A, said steam valve being connected with
n pipe terminating with an ordinary steam whistle V", in such a manner that a
release of the tension of the spring will open the steam valve in the pipe leading
to the whistle, or ring a bell as may be desired. V represents a hinged arm
attached by a proper connection to the retracted spring V, and W, is a notch which
will engage the free extremity of the hinged arm V. Now with the spring V
retracted and held in position by the free extremity of the arm Vill resting in the
notch W, it is evident that when the float U, is raised by the water in the
reservoir Cu to a certain height, its stem will come forcibly in contact with
the extremity of the hinged arm V, and disengage it from the notch W which
will allow spring V to actuate the steam valve or a valve to which it is attached,
thus sounding an alarm and warning the attendant that the pump L, is not
returning the water of condensation to the boiler A as fast as it is received into the
reservoir C. By these means the return of the water of condensation from the
boiler A is made secure thus avoiding all danger of low water in the boiler.
Grepresents a vessel contained within another vessel G, the space between the

page_text: two vessels forming a channel that connects the two portions of the pipe G" with
each other so that the exhaust steam in passing from the cylinder of the engine Fl
to the interior cavity of the vessel C will be compelled to pass around the
vessel G in the space between it and the exterior vessel G, thereby communi-
cating a portion of its heat to the vessel G. This vessel G₁ is provided with a
perforated top for the escape of steam that may be generated in it into the space
that surrounds it, and also with a pipe O, having a stop-cock, which pipe connects
with a reservoir H of water. By operating the cock in pipe O, water may be
admitted into the vessel G which may be evaporated in the manner already
described; the steam from such evaporation passing out of the perforations in
the top of the vessel G. The bottom of this vessel G is provided with a
pipe directed downward through the bottom of the vessel Gu to which pipe
a stop-cock is applied by means of which the contents of vessel C may be
drawn as occasion requires. This apparatus composed of vessels G and G
together with the reservoir H, and the pipes and stop-cocks described, forms a very
important part of my invention in that I supply thereby pure distilled water to
the boiler A to make good the waste or loss that may result from the
leakage and escape of steam and water in running the engines F¹ and D". Although
the cold air traversing the channels in the vessel C, will condense to water the
greater, if not the entire volume of exhaust steam passing at the same time through
said vessel that will be returned to the boiler A, by the pump L as set forth,-still
there will be a large volume of water lost daily by leakage of the boiler and engine
cylinders when in operation which must be re-supplied. By opening the cock in
the pipe O, to a greater or less degree water will be admitted to the vessel Gui
which will be readily evaporated by the heat of the exhaust steam, which surrounds
said vessel, in its passage from the steam cylinder F and D to the vessel C. The
steam resulting from the evaporation of this water will readily pass through the
perforations in the top of the vessel G¹¹ and from thence pass directly into the
vessel C to be condensed back to water in the manner described and conveyed into
the boiler A by means of the pump and the pipe connections. Thus, although
impure water may be admitted into the vessel G only pure water will pass
from said vessel in the form of steam, to be conveyed to the boiler. The impurities
of various kinds in the water admitted into the vessel G¹¹¹ from reservoir H, may be
drawn off from time to time by means of the pipes, which should be provided with
stop-cocks and which are connected with the bottom of said vessel. By these
means if the boiler A is filled with pure water the waste or loss thereof resulting
from running the engines may be supplied with pure water derived from impure
water thus effectually preventing the formation of scale or the accumulation of dirt
in the boiler A. In case however it is not desirable in practice to evaporate the
water that is admitted to the vessel G, from the reservoir H, by allowing
this vessel to become filled with water from this reservoir H, a continuous stream
may then be caused to flow through the perforations in the top of the vessel G
into the space between the latter and the vessel G by a proper adjustment of the
valve in pipe O. This water would then pass with the exhaust steam into the
vessel C, and become heated previous to its exit therefrom. Certain impurities
admitted with the water in the manner described into the vessel Gu would settle
to the bottom of this vessel and could be drawn therefrom as set forth. If it is
desired to add only pure or distilled water to the boiler A, from the vessel G the
latter vessel should not be permitted to fill with water and the water should only
be admitted into it as fast as evaporation takes place. M and M' represent the
respective pipes, with their valves that supply the engines with live steam from
the boiler A. N designates the pipe that supplies the vessel C, with cold air from
the air pump D¹. R designates the pipe that conveys the heated air from the
vessel C to the air heater B. Q is a pipe that extends between the lower extremity
of the steam channel in the vessel C, and the upper extremity of the air heater B;
By means of pipe Q, an uninterrupted channel is afforded for the exhaust steam
from the cylinders of the engines to the flue passage at the upper extremity of the

page_text: air-heater B passing through the open valve Q in said pipe after its passage
through the vessel C. R¹ represents a pipe connecting with the pipe Q and passing
into the reservoir H. It will be seen that the pipe R' passes to and fro a number
of times in the reservoir H before it, emerges to terminate in a connection with the
pipe Q. R is a valve closing the pipe by means of which the contents passing
in this pipe may be compelled to pass through the pipe R' in the reservoir H. Rui
is a valve by means of which the pipe Qmay be closed above the junction of the
pipe R' with the latter. Now with the reservoir H supplied with a flowing stream
of cold water, it is evident that by opening valve Q¹ and closing the valve R" in
the pipe any uncondensed steam passing from the vessel C from the two engines
would immediately pass by the channel already described through the pipe R' in
the reservoir H where said steam would be immediately condensed to water by the
cold water in said reservoir surrounding the pipe R' in its passage through said
reservoir, and it will be seen that the water of condensation in the pipe R' in the
reservoir H would flow by its own gravity through pipes Q and C into the
reservoir C" to be returned to the boiler A in the manner set forth. M" represents
a pipe with a valve, connecting the pipe M with the vessel S. By opening the
valve in pipe M, and in the pipe M", and also the valve Q and valve R" at the
same time closing the valve R¹ live steam from the boiler will pass through the pipe
G¹ thence around the vessel G and into the steam channels in the vessel C and from
thence pass through the pipe Q and pipe R' into the reservoir H in said
pipe R¹ & from thence back into pipe Q. to be discharged into the conductor
above the air heater B. After atmospheric air has been discharged or expelled
from the steam channel last described by the live steam from the boiler A, by
closing the valve in the steam pipe M¹ and the valve R" in the steain pipe Q a
partial vacuum will be immediately formed in the pipe R' in reservoir H. where
said pipe is exposed to the cold water flowing into and out of it.
"
With this
"ɔ
vacuum established in the pipe R¹ the pistons of the engines when put in
motion will be relieved of the weight of the atmosphere, thereby making low
pressure engines of both and economizing the production of power. If the exhaust
steam is not entirely condensed to water by the cold air passing through the
vessel C. such steam will immediately pass into the condensing pipe in the
reservoir H. where condensation cannot fail to take place. Under certain conditions
the apparatus just described for establishing a "vacuum" behind the pistons in the
engine cylinders may be dispensed with, the condensation of the steam being
carried on only in the vessel C. I desire to be understood as claiming that the
condensation of steam in a pipe traversing the reservoir H is a valuable though
not an indispensable auxiliary in my invention. P represents a pipe provided with
a stop cock that connects the pipe G' with the pipe N. By means of this pipe and
its stop cock steam may be added, if desired to the air by which the combustion of
fuel is carried on in the furnace, of the boiler A. K is a pipe leading from the
upper portion of the air heater B to the ash-pit of the furnace of the boiler A.
At the lower extremity of the pipe K it divides into two branches which enter the
ash pit of the furnace of the boiler. The lower branch T is provided with a
valve T¹ and terminates in the ash pit by a free extremity, and the upper
branch K¹ is provided with a valve K' and after entering and passing partly across
the ash pit in a horizontal direction, connects with a vertical pipe which in turn
connects at its upper extremity with a horizontal pipe E. provided with several
distributing pipes E¹ each one of which enter it at one extremity and extend across
the space above the grate in the boiler furnace. It will be observed that the
beating and distributing pipes E' are so arranged at a suitable distance from each
other that gases resulting from combustion rising from the burning fuel will pass
directly between then in their journey to the upper part of the furnace. The
pipes E are finely perforated at their free extremities and are also provided with
rows of perforations near their center extending their entire length so that any
gaseous elements discharged from said perforations under pressure will pass out in
jets at right angles and into the currents of combustible gases rising from the fuel,

page_text: and thereby become intimately mixed with the same thus effectually completing
the act of combustion. The horizontal pipe E and its perpendicular supporting
pipe are connected by a loose joint E shown by figure 5 composed of the opening e.
in the pipe E, and the entering portion el with its flange e² and dowel pin e³. The
fixed portion of the connection is maintained in the furnace of the boiler A. The
pipes E' should fit by loose joints into the apertures in the horizontal pipe E which
joints are of the greatest practical utility for allowing them to be quickly removed
and replaced without injury to the furnace, when it becomes necessary from any
cause to substitute new pipes for those which have been injured by heat. The
loose joints between pipes E and E¹ are of the same kind as the joint E above
described. In some instances the pipes E¹ may be dispensed with in which case
the heated gaseous elements would issue directly from the apertures in the pipe E
that in the other case would be occupied by one extremity of the pipes E' instead
of issuing from the perforations in said pipes as heretofore described. In practice
I shall sometimes apply furnace brick or other equivalent material that is highly
refractory to heat, to the upper and lower sides of the heating and distributing
pipes E for the protection of the same against the intense heat to which they are
exposed. I may adopt as a modification of the heating and distributing apparatus
above described, an apparatus for dispersing liquid and pulverized fuel in
horizontal directions above the grate bars and below the air heater in the fuel
chamber of the furnace. Said apparatus for dispersing the liquid and pulverized
fuel consists (see figure 4) of the receptacle 2, steam pipe 1, conducting
pipe 3, disks 4 and 5 for the lateral dispersion of the liquid or pulverized
fuel. The fuel above named admitted into the receptacle 2 would be
carried by the force of steam from the pipe, through the pipe 3 to the
disks 4 and 5 to be dispersed horizontally above the grate bars of the
furnace and below the heating and distributing arms E'. In this case the space
below the pipe E' would constitute the fuel chamber of the furnace while the space
above the said pipes would constitute the combustion chamber proper. I contemplate
the application of such a furnace to the melting, reduction or purification of ores,
metals or minerals or to any other purpose in the arts as well as for the production
of steam. In the practical operation of my invention (when it is desired to free
the engines from atmospheric pressure) pure water should be introduced into the
boiler A, and a fire from wood, anthracite or bituminous coal kindled in the furnace
on its grate. After the steam gauge indicates a pressure of steam in the boiler
exceeding the weight of one atmosphere the steam valves should be opened so as to
admit live steam from the boiler into the vessel S. after which the valve Q' and the
valve R in the pipe Q should be opened while the valve R" in the pipe Q, should
be shut. This will afford a continuous channel for the live steam from the boiler A
through the vessel S, pipe G¹, the space between the vessels G and G₁ into the
vessel C, and from thence through the pipes R and Q into the conductor above the
air heater B. After atmospheric air has been expelled from the channel just
described by the live steam from the boiler A the valve R in pipe Q should
be shut. Then cold water should be introduced into the reservoir H which will
instantly condense the steam in the therein contained portion of the pipe R¹
forming a partial vacuum behind the pistons in the cylinders F' D". I would here
add that in practice a small stream of cold water should be kept constantly flowing
into and out of the reservoir H to prevent the water therein from becoming heated.
When the steam pressure in the boiler has become sufficient the valve in pipes
M, M' should be opened and at the same time the door of the ash pit should be
closed. The action of the cylinder D" will at once give motion to the air pump D¹
and the water pump L. From the pump D' a current of air will be forced through
the pipe N, vessel C, pipe R, air heater B, pipe K and from the latter pipe, by its
two branches into the ash-pit beneath the grate and out of the perforations in the
combined air heater and distributor above the grate; or if the heating and
distributing pipes are not employed the air will be forced out of the apertures in
the horizontal pipe E'; said air in its course, through vessel C, and heater B will

page_text: become heated to a greater or less intensity by the exhaust steam in the vessel C,
and the escaping gases from the top of the boiler, passing through the heater B.
The advantage of supplying heated air beneath the furnace grate to carry on the
process of combustion of the ignited fuel above it need not be herein set forth; and
also the advantage of injecting heated gaseous elements containing oxygen and
hydrogen gases in jets into the combustible gases rising from the ignited fuel is well
known. It will be observed in this connection that the combined air heater and
distributor, composed of a vertical pipe connecting with the horizontal pipe E and
its perforated distributing branches E', from its position in the furnace of the
boiler serves to reheat the heated air and steam to a still greater intensity during
their passage through it whether they are discharged from the openings or
apertures in pipe E or from the perforated pipes E. By adopting the modification
of the air heater and distributor which allows the pipes E¹ to be raised or lowered as
described in my aforesaid patent the said pipes may be adjusted nearer to or further
from the ignited fuel than would be possible if the pipes were fixed permanently in
one position. In this case the application of furnace brick to the pipes E or the
encasing of each one of these pipes in a cylinder of fire clay might in some cases be
desirable. The encasing cylinders would be suitably perforated for the escape of
the gaseous elements. In some instances a fan might be used instead of the air
pump D although I prefer to use the air pump. As the perfect combustion of
the fuel required a certain volume of atmospheric air to every pound of carbon that
the fuel may contain. When air alone is used to effect its combustion by the use
of an air pump of a certain capacity if the quantity of carbon in the fuel burned
per hour is actually known by giving a certain activity to the air pump so that
from 325 to 350 cubic feet of air will be supplied in a proper manner to
the furnace, to every pound of carbon consumed therein per hour, an
approximately perfect combustion of fuel used may be realized. But, in the
application of an air pump in the manner described for measuring the
amount of air supplied to a furnace per hour the air must be heated before
it is discharged in the furnace; and part of this beated air must be discharged
into the current of combustible gases rising from the ignited fuel on the
grate as above described. By means of the pipe P, and its valve, steam may
be mixed with the air that is supplied to the furnace to carry on combustion.
In cases of the dispersion of liquid and pulverized fuel as set forth, the use of a
certain volume of steam mixed with the air discharged into the furnace especially
when the barometer shows unusual density of the atmosphere would conduce to
a greater economy in fuel. The exhaust steam after leaving the steam chest F
comes in contact with the pipe G" at the point that it enters the vessel S. and near
the point where the pipe G enters the boiler. This feature is very important and
will be particularly described hereinafter. After leaving the vessel S the exhaust
steam passes for a certain distance around the pipe G₁ which is enclosed in pipe G'
and thence through this pipe to the vessel C, where it traverses a channel or
channels, separated from the cold air channel only by the thickness of metal
sufficient to withstand the steam pressure. In this channel the condensation of
steam to water at or below the boiling temperature is effected by the cold air as
described; while in a continuation of this same channel viz: in the pipe R' in the
reservoir H is a "
"
vacuum thereby relieving the piston in the cylinder F¹ of
atmospheric pressure and greatly economizing power. In case that the current of
cold air supplied by the air pump D¹ to the vessel C, should not entirely condense
to water the exhaust steam passing to said vessel from the cylinder F¹ and D¹
said steam will immediately pass to the pipe R'. in the reservoir H. where its con-
densation must take place. Thus, the reservoir H. with its pipe becomes a valuable
auxiliary to the vessel C. and should be of ample capacity to meet all of the
necessary requirements. If it should not be desired to relieve the pistons in the two
engines of atmospheric pressure when in use the valve R¹ and also the valve R
in pipe may be opened, allowing a free channel from the vessel C, outward to
the atmosphere. In such case the reservoir H. and its pipe R' could be dispensed

page_text: with altogether. The water of condensation will flow by its own gravity from
vessel C, through pipe C' into the reservoir C" and flow thence to the force
pump L, to be returned to the boiler through the pipe G. The reservoir Cu
fullfils a very important office in my invention in supplying a vessel to contain
for a considerable period of time the water of condensation flowing from the
vessel C, in case of any derangement in the working of the force pump L. This
will prevent the steam channel in the vessel C, from being flooded with the water
of condensation should the force pump cease to work properly. The alarm
mechanism described would warn the attendant of any danger from the above
cause. This alarm mechanism may be omitted from reservoir C" and the glass
gauge with which it is provided depended on to indicate to the eye the depth of
water it may contain. The leakage of water from the boiler may be repaired by
allowing a small stream to flow into the vessel Qui through the pipe O. which leads
to the reservoir H. If the steam is only sufficient to repair the waste in the
boiler A and is in correct proportion to the size of the vessel Gill evaporation of
said water in said vessel will take place as fast as it is admitted from the effects of
the heat of the exhaust steam passing around said vessel G. The steam resulting
from the evaporation of said water will pass out of the perforated top of the
vessel G and enter the vessel C to be condensed with the exhaust steam. If
desired water may be so freely admitted into the vessel G from reservoir H that
it will pass through the perforated top of G¹¹¹ and with the exhaust steam enter
the vessel C. This would convert the steam channel in vessel C. into a water
heater. The water of condensation after passing the force pump L enters the
pipe G whose interior is continuous with the interior of the boiler A. It should
be borne in mind that when the water enters the pipe G¹ through pump L it is
heated so as to be near the boiling point, and that after entering pipe Quit is still
further heated by the exhaust steam until it reaches the vessel S. where its
temperature rises to only a few degrees below the temperature of the steam in the
cylinder of the engine F. It will be observed that in the vessel S the exhaust
stean from the cylinder F¹ comes in direct contact with the water heating
pipe G at or near the point that its expansion commences to take place thus
communicating to said pipe a degree of heat a little below the heat of the steam in
the boiler A and that it continues to give out heat as its expansion takes place
through the entire length of the enlarged portion of pipe G" consequently with the
water heated to or near the boiling point as it passes the pump L into the pipe Q"¹
it is evident that it will enter the boiler A, in the manner specified at a temperature
a few degrees below the temperature of the water therein, if the steam
is not worked expansively in the cylinders of the engines. The vessel S. is only a
continuation and enlargement of the pipe G¹, and the water heater within it, is
only an amplification of pipe G. The importance of making the interior of the
pipe G continuous with the interior of the boiler A must not be overlooked, as
water heated to a temperature that the water in said pipe acquires in the vessel S.
and the pipe G¹ could not be readily returned by a pump or other apparatus to the
boiler A. In some cases the air heater B might be dispensed with, the heated air
from the vessel C, being conveyed directly to the furnace of the boiler A. and if
desired, the water heating apparatus (composed of vessel S, pipe G" and the
pipe G) may be dispensed with the water being returned directly to the boiler by
the pump L. In the present application the greatest simplicity and durability are
combined in an apparatus for the same purpose without the necessity of a
separate chamber to complete the process of combustion and a great advantage is
derived from the parts being easily adjusted in case of repairs. Having thus fully
described my invention what I claim as new and desire to secure by letters patent
is: 1 The combination of the horizontal pipe E, its perpendicular pipe, the
perforated distributing pipes and the loose joint connections of these pipes
substantially as described. 2 The combination of the air-heating and distributing
device, a furnace, the vessel C and the air-heater B, substantially as described.
3. The combination of the air-heating and distributing device arranged in the

page_text: furnace above the grate, with the device 4 and 5 above the grate for dispersing
liquid and pulverized fuel substantially as described. 4. The combination of the
vessel C, constructed of concentric tubes with closed extremities forming spaces
between said tubes, and the short connecting tubes between said spaces sub-
stantially as described. 5. The combination of the outside shell of the air-heater B,
the heating flues therein, and the transverse partitions, the latter being cut away
at alternate portions of the diameter of said shell whereby gaseous elements
passing through said vessel under pressure in a zig-zag direction will absorb a
large amount of heat passing through the said flues substantially as described.
6. The combination of the air pump D¹ for measuring the volume of heated air
supplied to the boiler furnace, the air heater at the top of the boiler, and the pipe
connections and their cocks between the said pump and beater substantially as
described. 7. The combination of the reservoir C₁, the pump L, and the pipe
connections provided with stop cocks substantially as described and for the
purpose specified. 8. The combination of the reservoir C¹¹, air heating vessel C,
and the apparatus composed of the float and stem thereof, the notch W, the hinged
arm, the spring, and an alarm, substantially as and for the purpose set forth.
9. The combination of the vessels G and G, the pipe O, its stop-cock, the
reservoir H and the air-heating vessel C substantially as and for the purpose
specified. 10. The combination of the air-heating vessel C, vessel G¹, its perforated
top, the enclosing vessel Q1111 and the outlet pipe at the bottom provided with a
stop-cock, substantially as described. 11. The combination of the steam pipe G
with the apparatus consisting of the vessels G and G11, the vessel C, and the
pump L with their pipe connections and stop-cocks substantially as described.
12. The combination of the air-heating vessel O, the exhaust pipe of engine F¹, the
vessel S, the pipe G", the pipe G¹, boiler A, and pump L, the interior of pipe G
being continuous with the boiler substantially as described. 13. The combination
of the air-heating vessel C, the engine cylinder F¹, vessel S, pipe G", pipe G₁ and
boiler A substantially as described. 14. The water heating device consisting of
the pipes G, G", with or without the vessel S, in combination with the boiler A,
pump L, reservoir CH and vessel C substantially as described. 15. The process
consisting in heating by the exhaust the air used for carrying on the combustion
of fuel and at the same time re-heating the water derived from its condensation to
a very high degree of temperature before the latter is returned to the boiler,
substantially in the manner and for the purposes described. 16. The combination
of the vessel C (as a water heater) the vessels G and G, pipe O, and the
tube G¹, the air pump and the pipe N, reservoir H, substantially as described.
17. The combination in a low pressure engine of the cylinder F, boiler A, vessel C,
reservoir C, water pump L, air pump D¹, reservoir H, pipe R, air heater B, and
the pipes with cocks, cominunicating with said parts, substantially as described.
In witness whereof, I the said Virgil Warren Blanchard have hereunto set
my hand and seal this thirtieth day of November in the year of our Lord
One Thousand Eight Hundred and Eighty two.
VIRGIL W BLANCHARD (L.S.)