IMPROVEMENTS IN STEAM GENERATORS AND FURNACES, AND ROTARY ENGINES FOR USE THEREWITH
Year: 1880

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of "IMPROVEMENTS
IN STEAM GENERATORS AND FURNACES, AND ROTARY ENGINES FOR USE
THEREWITH." A communication from abroad by Joseph Edwin Culver, of
Jersey City, in the County of Hudson and State of New Jersey, United
States of America.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 5th August 1880.
$6
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. IMPROVEMENTS IN STEAM GENERATORS AND FURNACES,
AND ROTARY ENGINES FOR USE THEREWITH." [A communication from abroad by
Joseph Edwin Culver, of Jersey City, in the County of Hudson and State of New
Jersey, United States of America.]
These improvements relate, first, to steam generators wherein the heated gaseous
products of combustion can be commingled with the steam for use as motive power,
or for heating and other purposes, or the steam and heated products separately used;
and, secondly, to engines for use with steam or other gases or fluids as the motive
power.
In the improved generator the fire box is preferably contained within the water
space of the boiler, and connects with an upper flue chamber from which vertical
flue tubes pass to a smoke chamber in the lower part of the water space. The
smoke chambers are made in the form of hollow discs of circular form, and of a
diameter somewhat less than the boiler, and the vertical flue tubes are placed
closely together, sufficient space being left between them for circulation of water.
At the front part of the boiler the chambers are connected by partitions that form
the fire box which is provided with a grate. There are openings in the side of the
boiler to the fire box above and below the grate provided with doors. The lower
smoke chamber is supported on short legs, so that the water has free access beneath
it, and the fire box and upper smoke chamber are connected by an opening. The
lower smoke chamber connects with a smoke pipe that is also connected with the
steam space by a pipe furnished with a cut-off, so that the products of combustion
and the steam can be carried off together or separately. The steam entering the
pipe becomes mixed with the heated gases, and at the same time the steam jet
tends to increase the upward draft. In operation the products of combustion pass
from the fire box to the upper chamber, and from thence, as they cool, they descend
by the vertical flues to the lower chamber. The flues and chambers are thus
heated, and by their large extent of heating surface rapidly and uniformly heat
[Price 6d 1

page_text: the water. The products of combustion pass from the lower chamber to the smoke
pipe, and are conveyed away for use alone or mixed with more or less steam, as
desired.
The heated mixture may be conveyed to the cylinders of an engine, which may
be worked as a high pressure engine, or may be provided with a suitable condenser.
The mixture may also be used simply for purposes of heating and ventilation, or used
in connection with evaporating pans. For heating purposes a radiator consisting
of horizontal and vertical tubes would be connected to the smoke pipe and with a
chimney for the final escape of the gases, and for evaporating the pan would
contain tubes that connect with the pipe to equally distribute the heat throughout
the liquid in the pan. The steam can be used under pressure, or at atmospheric
pressure only. If it is desirable to use steam under extraordinary pressure, it can
be safely accomplished by nesting boilers built on this plan, one within another;
when, for example, if the outer boiler can sustain a pressure of ten atmospheres
the inner boiler can, without being subjected to greater strain than the former,
sustain a pressure equal to twenty atmospheres. If it be desired to use the
residual gases of combustion under pressures above that of the atmosphere, the
furnace doors must be closed tight with strong fastenings, and the air supply to
the fire kept up by a pressure blower adapted to the purpose. A safety valve will
then be necessary in the smoke pipe in addition to the safety valve of the boiler.
At atmospheric pressure the valve can be left open for the escape of the unused
smoke.
The motor consists of a wheel carried by a shaft supported in suitable bearings.
The rim of the wheel is formed with a broad flat outer surface, and upon this outer
surface at opposite sides are fixed abutments fitted within a fixed steam way, the
same being sustained by suitable supports and extending around the whole or any
portion of the wheel desired. The steam way corresponds in shape to the rim,
and if it extends around one half of the wheel one abutment enters the upper end
of the steam way as the other leaves the lower end. At the upper end of the steam
way is a pipe for supplying the steam, gas, air, or other motive force, and in this
pipe is a tubular valve or gate which has an opening at its lower end to the steam
way. At the side opposite to the opening the valve is rounded or bevelled so that
it can be readily lifted by an inclined forward portion of the abutments. This
allows the abutments to pass, the gate or valve then falling to place again by
gravity or steam pressure, this lifting movement only cutting off the steam for the
moment the valve is fully raised.
The valve may be operated, if desired, by an eccentric or cam or lever. If steam
is to be worked expansively, a suitable cut off must be provided in the steam
supply pipe.
The valves are suitably packed, as are also the abutments, to render them tight
against the inner surface of the steam way.
The joint where the edges of the rim of the wheel and steam way come together
will also be suitably packed, and I prefer for this purpose to form the edges with
grooves and insert in the grooves a packing, which may consist of a bar of metal
suitably fitted, or of a spring metal plate rolled in circular form with the edges
lapped. This bar or roll presses against the inner surfaces of the grooves and
prevents escape of steam.
In operation the steam, air, water, or gas entering by the supply pipe acts upon the
abutment, and, by reaction against the back of the valve, the wheel is forced around
until the abutment passes out at the bottom of the steam way, where the exhaust
takes place. At the same moment the other abutment enters the steam way and
is acted upon in the same manner. If the steam way extends entirely around the
wheel but one abutment will be required, and the exhaust must then open at the
terminus of the steam way back of the gate. Any suitable condenser may be
connected with the exhaust to create a partial vacuum in front of the abutment,
and thus increase the power.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Melville Clark in the Great Scal Patent Office on the
5th February 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN STEAM GENERATORS AND FURNACES,
AND ROTARY ENGINES FOR USE THEREWITH." A communication from abroad by
Joseph Edwin Culver, of Jersey City, in the County of Hudson and State of New
Jersey, United States of America.
These improvements relate, first, to steam generators wherein the heated gaseous
products of combustion can be commingled with the steam for use as motive power
or for heating purposes, or the steam and heated products separately used;
and, secondly, to engines for use with steam or other gases or fluids as the motive
power.
In the improved generator the boiler may be constructed of sheet metal or boiler
iron, the strength of which must be adapted to withstand the strain to which it is
to be subjected; the flues may be constructed of sheet metal boiler tubes, or cast
iron, or of any suitable material, and the furnace may be of ordinary construction.
When the generator is to be used solely for heating purposes, or when the tension
of the steam in the boiler is to be carried only a few degrees above atmospheric
pressure, the fire box may advantageously be constructed within the water space
of the boiler and connected with an upper flue chamber from which flue tubes
pass to a smoke chamber in the lower part of the water space; but when it is
intended to furnish motive power, and the steam pressure within the boiler is to
be raised to two or more atmospheres, then I prefer to have the fire box constructed
outside the boiler shell, and to be connected with a system of intercommunicating
flue tubes arranged within the water space of the boiler, so that the smoke shall
traverse them from above downward. If the flues intercommunicate freely at the
bottom of the boiler only, the desired result can be but imperfectly obtained; but
if, besides these junctions beneath, free intercommunication exists amongst all the
uppermost flues also, a perfect working will be assured; nevertheless, I prefer that
the intercommunications shall be yet more numerous, and be distributed throughout
the entire system of flues from top to bottom.
It has been estimated by experiment that the total capacity of the submerged
flues in the generator of this Invention should equal about one third of the water
space in order that the smoke and steam may emerge from the boiler at a common
temperature when the grate surface is about one third the customary proportions.
When a considerable depth of the water space is called for an upright cylindrical
boiler is the best, but the shape of the boiler may be determined by other require-
ments. However, the longer and more numerous the flue tubes, and the greater
the total capacity of the flues relatively to that of the water space, the more
effectually will the water be heated and the smoke cooled, the consumption of fuel
remaining the same.
Accordingly as may be preferred for special purposes, or whensoever it is sought
merely to illustrate in practice the novel principle made use of in the construction
of the improved generator, the flues may consist of tubes alone, or of chambers
alone, or of any suitable combination of chambers and tubes, provided always that
they be arranged within the water space of the boiler below the water level;
provided also that they do freely intercommunicate one with another: provided
furthermore that they do so connect with the furnace and smoke stack that the
smoke shall traverse them from above downwards, and provided, moreover,
that the descending smoke in every flue and in every part or section thereof is
left free to descend according as it is cooled, or to maintain a higher level according

page_text: as its retains its heat and rarefaction. Thus the continual cooling of the smoke in
the flues and its increasing gravity accelerate its descent, while throughout the
breadth and depth of the water space the smoke in all the flues maintains at the
same level a uniform temperature, an equilibrium not liable to be disturbed by
variable draughts. The water boils at the surface and steam does not bubble up
from the lower part of the boiler. The temperature. of the water decreases from
above downwards, but it is uniform throughout any given horizontal plane. At
all times the hottest stratum of water is opposed to the hottest flues, and the
coolest stratum to the coolest flues. The coolest smoke in the lowermost flues is
carried off by one large flue (or more) continued through the boiler shell for this
purpose. Into this discharge flue, just outside the boiler, a two way cock or valve
of ample size is inserted, through which the discharge flue connects at option with
a chimney to carry away the unused smoke, or with a smoke pipe termed a mixing
pipe that is also connected with the steam space by a pipe furnished with a cut
off, so that the gaseous products of combustion and the steam can be carried off
together or separately for use. This mixture may be used to drive a suitable
motor, for heating purposes, for evaporating liquid, for extinguishing fires, and for
other uses.
In the accompanying Drawing forming a part of this Specification, Figure 1 is a
central vertical section of the generator and furnace; Figure 2 is a horizontal
section of the same on line x-x, of Figure 1. Similar letters of reference indicate
corresponding parts; a is the side of the boiler shell; b, the bottom, and c the top,
which are formed of sheet metal or boiler iron. Within the boiler are the upper
and lower smoke chambers d, e. These are made in the form of hollow discs of
circular form and of a diameter somewhat less than that of the boiler, and are
connected by vertical flue tubes f, which are placed closely together, sufficient space
being left between them for circulation of water. At the front part of the boiler
the chambers d, e, are connected by partitions g that form the fire box h, which is
provided with a grate. There are openings in the side a of the boiler to the fire
box above and below the grate provided with doors. The lower smoke chamber e
is supported on short legs, so that the water has free access beneath it. The fire
box and chamber d are connected by an opening '; i is the pipe for carrying off
the steam and products of combustion. This connects by a pipe k with the smoke
chamber e, and by a pipe with the steam space of the boiler. A suitable valve
will be provided in pipe for regulating the flow of steam to pipe i. The steam
entering the pipe becomes mixed with the heated gases, and at the same time the
steam jet tends to increase the upward draft. In operation the products of
combustion pass from the fire box to the chamber d, and from thence as they cool
they descend by flues f to chamber c. The flues and chambers are thus heated,
and by their large extent of heating surface rapidly and uniformly heat the water.
The products of combustion pass from chamber e to pipe i, and are conveyed away
for use alone or mixed with more or less steam as desired. The heated mixture
may be conveyed to the cylinders of an engine, which may be worked as a high
pressure engine, or may be provided with a suitable condenser. The mixture may
also be used simply for purposes of heating and ventilation, or used in connection
with evaporating pans. At t I have shown a radiator consisting of a horizontal
and vertical tubes which will be connected to pipe i, and with a chimney for the
final escape of the gases, thus utilizing the mixture of heated gases and steam. Atu
is an evaporating pan containing tubes that connect with pipe i, so that the heat
shall be equally distributed throughout the liquid in the pan. The generator and
furnace may also be used for other purposes than those named, and in all cases will
give good results compared with the amount of fuel consumed. The steam can be
used under pressure, or at atmospheric pressure only.
Figure 3 is a sectional side elevation of the motor or rotary engine, Figure 4
being a horizontal section of the same on line x-x, of Figure 3, and Figure 5 a
transverse section of the packing hereafter referred to. A is a wheel carried by
shaft m, which is supported in suitable bearings. The rim n of the wheel is

page_text: formed with a broad, flat, outer surface, and upon this outer surface at opposite
sides of the wheel are fixed abutments o, o. B is the fixed steam way, the same
being sustained by suitable supports and extending around the whole or any
portion of the wheel desired. The steam way corresponds in shape to the rim n,
and, as shown, it extends around one half the wheel, so that one abutment o enters
the upper end of the steam way as the other leaves the lower end. At the upper
end of the steam way is a pipe p for supplying the steam, gas, air, or other motive
force, and in this pipe a tubular valve or gate g, which has an opening at its lower
end to the steam way B. At the side opposite to the opening the valve is rounded
or bevelled so that it can be readily lifted by the inclined forward portion o¹ of the
abutments o. This allows the abutments to pass, the gate or valve then falling to
place again by gravity or steam pressure, and it will be seen that this lifting
movement will not cut off the steam, except for the moment when the valve is
fully raised. The valve g may be operated if desired by an eccentric or cam or
lever, and I do not limit myself in that particular. If steam is to be worked
expansively, a suitable cut off must be provided in pipe p. The valve will be
suitably packed, and the abutments o also provided with packing to render them
tight against the inner surface of the steam way. The joint where the edges of
rim n and steam way B come together will also be suitably packed. I prefer for
this purpose to form the edges with grooves 7, as shown in Figure 4, and insert in
the grooves a packing &, which may consist of a bar of metal suitably fitted, or of
a spring metal plate rolled in circular form with the edges lapped, as shown most
clearly in Figure 5. This bar or roll presses against the inner surfaces of groover 1,
and prevents escape of steam.
In operation the steam, air, water, or gas entering by pipe pacts upon the
abutment o, and by reaction against the back of the valve the wheel A is forced around
until the abutment passes out at the bottom of the steam way where the exhaust
takes place. At the same moment the other abutment o enters the steam way and
is acted upon in the same manner. If the steam way extends entirely around the
wheel, but one abutment will be required. The exhaust must then open at the
terminus of the steam way back of the gate. Any suitable condenser may be
connected with the exhaust to create a partial vacuum in front of the abutment
and thus increase the power.
I prefer a steam way of rectangular shape, but do not limit myself to any
particular shape for the steain way, nor to any form of packing exclusively.
Instead of a sliding steam gate the gate may be hinged and the abutment also
hinged to be depressed as it passes beneath the gate; the abutment will in this
case be fitted in a recess in the rim of the wheel.
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the.
herein before in part recited Letters Patent is,-
1st. In steam generators, a system of intercommunicating flues which are
distributed through the water space of the boiler, extending from beneath the
water level downward to near the bottom of the boiler, the uppermost parts of
which are connected by one or more openings with the combustion chamber of the
furnace, and the lowermost parts freely intercommunicate one with another and '
terminate in a common escape flue that passes out through the boiler shell (or
plate), and is continuous with the smoke stack, substantially as shown and
described.
2nd. The combination of the boiler and furnace with a system of interconi-
municating flues distributed through the water space, from beneath the water
level to near the bottom of the boiler, the uppermost parts of which are
connected through one or more openings with the combustion space of the furnace,
and the lowermost parts freely intercommunicate and terininate in a common
smoke way that passes out through the boiler plates and is continuous with the
Sinoke stack, substantially as shown and described.
3rd. The boiler and furnace, the flues of which constructed either of tubes only

page_text: or of chambers only, or of any suitable combination of chambers and tubes, are
arranged within the water space of the boiler below the water level and freely
intercommunicate one with another, especially at their lowermost parts, so
connected with the furnace and with the smoke stack that the smoke shall traverse
them from top to bottom, so intercommunicating that the descending smoke in
every flue and in every branch and segment thereof shall be left free to descend
according as it is cooled and its gravity is increased, or to maintain a higher level
according as it retains its heat rarefaction, so that the descending smoke preserves
in all the flues at the same level a uniform temperature, an aeractatic equilibrium
not liable to be disturbed by variable drafts, whereby the water boils at the surface
and steam does not bubble up from the lower part of the boiler, whereby the
temperature of the water in the boiler decreases from above downward, but is
uniform throughout any horizontal plane, through whereby at all times the hottest
stratum of water is opposed to the hottest flues, and the coolest stratum to the
coolest flues, whereby also the smoke can be cooled to the lowest degree attainable
within the boiler, and the production of steam correspondingly augmented,
substantially as shown and described.
4th. The mixing pipe i connected with the discharge flue of the boiler and by
pipe with the steam space, the former conveying smoke, the latter conveying
steam to mingle together therein, substantially as shown and described.
5th. The combination of mixing pipe i with the furnace and boiler, as described
and for the purposes set forth.
6th. The rotary engine or motor, consisting of wheel A provided with rim n, and
fixed abutments o combined with steam way B that cover the rim, and pipe p
fitted with sliding gate g, substantially as specified.
7th. The tubular gate g formed with a bevelled end and front opening combined
with steam way B, steam pipe p, and wheel A, having abutments o formed with
inclines o¹, as and for the purposes set forth.
8th. In rotary engines the wheel A and steam way B formed with their
contiguous edges grooved as at r, and fitted with packing s, as set forth.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Fourth day of February, A.D. 1881.