Improvements in Steam Generators.
Year: 1898

page_text: Date of Application, 29th Mar., 1898-Accepted, 18th June, 1898
COMPLETE SPECIFICATION.
Improvements in Steam Generators.
I, DAVID MOULTON. THOMPSON, of 29, Wilcox Street, Providence, County of
Providence, State of Rhode Island, United States of America, Engineer, do hereby
declare the nature of my invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
The invention has reference to an improvement in steam-boilers and furnaces
therefor. The invention consists in the peculiar and novel construction of the
steam-boiler, the water-tube circulating attachment and the furnace whereby the
more perfect combustion of the fuel in the furnace is secured, the circulation
of the water increased, the separation of the steam facilitated and better economic
results secured, as will be more fully set forth hereinafter.
In the economic generation of power the steam-generator performs the most
important function, because the most perfect steam-engine can utilize only a
portion of the heat stored up in the steam-generator. To secure the best and most
economic results, the fuel must be burned under the most favorable conditions
possible for the perfect combustion of the carbon in the fuel and of the volatile
gaseous products disengaged by the heat and the disintegration of the fuel on the
grate, not only must the proper quantity of air be supplied to the fuel and the
gases, but the gases must have ample room to expand, time for each atom to
combine with the oxygen of the air and, above all, the gaseous products must be
maintained at a high temperature until every atom of carbon is consumed and
converted into heat.
The heat produced by the combustion of fuel may be divided into the heat of the
products of combustion which in passing through the flues, or tubes, of the steam-
generator is absorbed by the water and stored up for useful work, and radiated
heat which can be reflected and deflected, but always acts locally on the surfaces
surrounding the incandescent fuel, or flame.
One object of this invention is to construct the furnace of a steam-generator
so that the gaseous products of combustion may expand and, while the atomic
mixture is facilitated, be maintained at a high temperature to facilitate the perfect
combustion of the same.
Another object of the invention is to so arrange the furnace that the expanded,
mixed and highly-heated products of combustion from one grate will pass
over the incandescent fuel of another grate and then enter a combustion chamber
before they enter the tubes of the steam-generator.
Another object of the invention is to utilize the radiated heat of a furnace of the
above-mentioned construction by conducting the same into the feed-water supplied
to the generator.
Another object of the invention is to prevent the deposit of soot in the tubes of a
steam-generator and the discharge of black smoke.
And another object of the invention is to more completely separate the impurities

page_text: held in suspension in the feed-water before the water enters the main body of the
steam-generator.
And a further object of the invention is to reduce the height of the vertical
tubular boiler without impairing its efficiency.
In steam-generators, as heretofore constructed, and particularly in the type
known in the arts as vertical tubular boilers, the furnace was placed below the
vertical tubular boiler and the products of combustion impinged on the boiler
and passed from the fire upward through the vertical tubes, the volatile gases,
with the unconsumed carbon, soot, ashes, and vapor, coming in contact with the
surface of the boiler, and the tubes were chilled by the comparatively low
temperature of the boiler and adhered to the interior surface of the tubes, thereby
clogging the tubes, reducing the draught and the steam-generating efficiency
of the tubes.
To avoid this clogging of the tubes and secure the more perfect combustion
of the volatile carbon in the fuel, I place two furnaces side by side in front of the
vertical tubular boiler and practically on a level with the lower tube-sheet of the
vertical tubular boiler, I enclose these furnaces with fire-brick, or other similar
material, and connect the rear of these furnaces so that the products of combustion
from one furnace will pass over the fire of the other furnace and then into a large
combustion-chamber from which they pass under the vertical tubular boiler and
upward through the tubes of the same to the uptake, or may surround the lower
part of the vertical tubular boiler and enter the tubes to be carried to the uptake
and chimney.
To these ends the invention consists in the peculiar and novel construction of
the furnaces and the combination of the parts, as will be more fully described
hereinafter and more particularly pointed out in the claims.
I have elected to illustrate in the drawings the furnaces as applied to a vertical
tubular boiler showing the preferred form of construction, but do not wish to
confine myself to the use of the furnaces in connection with this particular form
or construction of the boiler.
Figure 1 is a vertical sectional view showing the furnaces in connection with a
vertical tubular steam-boiler and auxiliary water-tube steam-generators.
Figure 2 is a transverse sectional view of the furnaces showing the water-jacket
enclosing the furnaces and the generating tubes extending through the furnaces.
Figure 3 is a horizontal section, on the line X-X of Figure 1, showing the
flame-chamber connecting the two furnaces.
Figure 4 is a vertical section showing the relations of the furnaces, the water-
tubes and the vertical steam-boiler to each other.
Figure 5 is a vertical transverse section, on the line X X of Figure 4,
looking toward the front of the steam-generator.
Figure is a vertical transverse sectional view showing the two furnaces,
the combustion-chamber and the water-tubes.
Similar letters and numerals of reference indicate corresponding parts in all
the Figures.
In the drawings A indicates the furnace to which fuel is being supplied, or
has last been supplied, and A¹ the furnace in which the fuel is in the incandescent
state after the more volatile carbon has passed off.
The two furnaces are separated by the partition-wall A2 which extends from the
front to or nearly to the end of the grates A3-A3; they are enclosed by the side-
walls AA and covered by the arches A5 A5, preferably of fire brick resting
on the side walls and the partition wall A².
The two furnaces A and A¹ are connected at the rear by the large preferably
semi-circular flame-chamber A and at the front by the opening A7 in which the
swinging-gate A8 is placed, this gate A8 controls the exit from the furnaces to
the combustion-chamber A° and by swinging the gate from one side to the other
either one of the furnaces may be connected with the combustion-chamber A,
-under the grates are the ash-pits A 10-A10 and on the rear ends of the grates the

page_text: bridge-walls A-A", an opening connects the rear of the ash-pits with the
vault A in which the car.A¹³ forms a convenient receptacle for the removal of the
ashes.
The jacket A extends over the side walls of the furnaces, around the wall of
the flame-chamber and over the arch of the combustion-chamber,-the jacket is
made up of sections containing each two or more compartments A15 separated by
partitions having the openings A16 to form connections between all the chambers,
or cells, in each section.
The sections are connected by the pipes A" with the water-supply and with the
pipes A18 by which the heated water is delivered directly to the boiler or to a
settling chamber connected with the boiler, as is shown in Figure 1, or to a pump
by which it is delivered to the boiler.
The furnaces are provided with any suitable fire and ash-pit doors and devices
for controlling the draught and air supply.
I will now describe the operations of the furnaces in their normal condition
when the fires have been burning for a sufficient time to heat the fire-brick sides
and arches, and, with the gate A in the position shown in Figure 2, using bitumin-
ous or other coal liable to produce the objectionable black smoke.
The coal supplied in the usual manner to the fire in the furnace A is, owing to
the fire and the great heat of the fire-brick or other refractory material of the
sides and arch of the furnace, quickly heated so as to rapidly disengage the volatile
gases rich in carbon; these gases and the air drawn into the furnace expand and
pass in nearly straight currents over the bridge-wall and enter the semi-circular
arched space of the flame-chamber where, by the change in the direction of the
currents, the shape of the arched roof, the increased area of the chamber and the
heat of the walls, the gases and air mix and burst into flame. The complete com-
bustion of all the carbon in the gases and the prevention of smoke
is so much a
matter of atomic mixture, time and heat that to secure
the desired result I pass the gases from the flame-chamber through the
furnace A¹, over the incandescent fuel on the grate of this furnace and through
the draught-opening A7 into the arched combustion-chamber A9 where the now
thoroughly-mixed and heated gases can again expand and, under the influence of
the heat of this chamber, form a final and complete union of the oxygen of the
air with any atoms of carbon still remaining in the products of combustion.
Two arched openings A20-A20, lower than the arch of the combustion-
chamber A9, connect the combustion-chamber with the chamber A21 under the
vertical tubular boiler B and permit the heated products of combustion to pass
through the tubes of the boiler to the chimney. The heated products of combustion
may be conveyed from the combustion-chamber A to any other form or construc-
tion of boiler.
The combustion of the fuel in this furnace is so complete that, as no carbon can
pass through the boiler, the smoke is of a light color, nearly invisible, because it
contains no coloring matter,-no soot collects in the tubes or on any other part
of the boiler and fine ashes are collected in the flame-chamber, the combustion-
chamber and the chamber A21, because by the increased area of these chambers
the velocity of the flow of the gases is reduced and ashes, or incombustible matter,
s precipitated in these chambers.
The boiler B, preferably used in connection with the furnaces, as shown in
Figure 1, is a vertical tubular boiler having the central open space B¹ surrounded
by the tubes B2, the central space B¹. connects with the central water-
column 133 extending from the lower tube-sheet of the boiler downward to the
mud-drum B4, the circulating tube B³, preferably provided with a funnel-shaped
apper end, is placed into the water-column B³ and divides the same into a central
lescending and an annular ascending space.
The mud-drum 134 connects with the transverse chamber B6 provided on the two
pposite sides with the mud-drums B7-B7, the blow-off pipes B8-B8 connect with
he mud-drums BBand.the, blow-off. pipe B connects with the mud-drum B*.
These blow-off pipes are provided with proper gate-valves, as shown in Figure 1,

page_text: and the impurities collected in these mud-drums may be discharged through these
blow-pipes from the bottom of the mud-drums as often as the nature of the
water used requires.
The series of water-tubes 1310 are connected with the transverse chamber 136
above the two mud-drums B7-B and extend upward through the flame-chamber
on an easy curve and extend in an upward inclined direction through the furnaces A
and A and have their other ends secured in one of the chambers B-B located
at the front of the boiler, which front is provided with suitable doors by which
access is had to the chambers B, another series of water-tubes B12 extend in an
inclined direction from each of the chambers B", through the combustion-
chamber A and the chamber A2 to the fitting B3 which is connected with the
steam-generator by the pipe Bª,- -a pipe 115 extends from each of the fittings B13
downward and connects the same with one of the mud-drums B7.
By this construction the two water-tube sections, one from each furnace, are in
all respects independent of each other and free to expand and contract, the steam
generated in each is delivered by the pipe B14 to the boiler and perfect circulation
of the water in each section is secured by the pipe B15 which forms a direct con-
nection between the upper ends of the water-tubes of each section with the lower
water connection of the tubes. The rapid circulation of the water in these tubes B¹º
and 1 and their exposure to the direct action of the rays of the heat from the fire
and the flame in the furnaces enclosed by the refractory material secures an evapora-
tive efficiency of the highest value.
The feed-water, as has been hereinbefore described, is heated in the cellular
jacket A4 the several sections of which are connected with the pipe A18, the
pipe B16 may connect the pipe A18 with the feed-pipe B1, as is shown in Figure 1,
but I prefer to connect the pipe A18 with a steam or feed pump and connect the
pump with the feed-pipe B, so as to relieve the cellular jacket from the pressure
of the steam and the static pressure of the water in the boiler, and subject the
jacket only to the pressure incident to the weight of the water in the jacket.
The feed-pipe terminates preferably in a rose B18 and the feed-water is delivered
into the mud-drum B+ preferably at a point below the ash-pit.
:
I will now more fully describe the effect of the arrangement described on the
water used in the generation of steam as before described the feed-water is
supplied first to the cellular jacket A4 and its temperature is raised by the absorp-
tion of the heat conducted through the fire-brick or similar lining of the furnaces.
The feed-water is preferably supplied to the lowest part of the jacket from a tank
the water-level in which is maintained but little above the highest part of the
jacket.
The water heated in the cellular jacket is preferably delivered by the pipe or
pipes A18, connected with the upper part of each section of the jacket, to a tank
from which it is forced into the boiler by means of a feed-pump connected with the
feed-pipe B. The pipe A18 may be connected directly to the feed-pump, or, if the
cellular-jacket A were strong enough to withstand the pressure, the feed-water
might be forced by the feed-water-pump into the lower part of the jacket and
the upper part of the jacket might be connected directly by the pipe 116 with the
feed-pipe 17 in either arrangement the feed-water is heated to or nearly to the
boiling point in the cellular jacket and its temperature is materially increased
in its passage through the feed-pipe from the upper end of the boiler to the
mud-drum where it is preferably delivered in a divided state or spray.
When water is heated the capacity to hold matter in suspension is diminished,
the feed-water discharged from the feed-pipe into the mud-drum precipitates the
impurities contained in it, a large part of the feed-water enters into the transverse
chamber 16, passes through the water-tubes B10 and B12 into the fitting 1313, the
steam generated in this passage and some of the water enters the boiler through the
pipe B and the greater portion of the water descends through the pipe B15 to
the mud-drum B7 where the now more concentrated water deposits the impurities
held in suspension and the purified water re-enters the water-tubes B10 and some of

page_text: it the mud-drum 13, while a portion of the water required mixes with the water
descending through the circulating tube 15 and ascending through the annular
space between the circulating tube B and the column B³.
This continuous circulation of the water in the boiler by which the water made
denser by the partial conversion into steam descends to the mud-drums and
reascends in contact with the heating surface, so facilitates the separation of
the impurities and their precipitation in the mud-drums where they are not affected
by heat and may be readily blown off, that, in practice, after an extended use with
inferior water, not the slightest precipitation of impurities or scale is found on
the tube surfaces or tube-sheet of the boiler. Efficiency and durability are
secured by this arrangement.
In practice the furnaces are alternately fired, the firing and ash-pit doors of the
furnace that is being fired are open and the draught-opening A7, controlled by the
gate A8, is closed, while the firing and ash-pit doors of the other furnace are closed
and the draught-opening A7 of this other furnace is open. When the other furnace
is fired the gate A8 is reversed. The gate A8 may be connected by suitable
mechanism with the furnace doors so that by opening the firing door of a furnace
the gate is swung over to close the outlet of this furnace and compel the gases to
pass through the flame-chamber and, the furnace not being fired, through the
draught-opening A' to the combustion chamber.
In the modified form shown in Figures 4, 5 and 6 of the drawings, A indicates
the furnace on the left-hand side of the steam-generator which, as shown in the
drawings, is the furnace to which the fuel has been last supplied; A¹ the furnace
on the right-hand side in which the fire has given up its volatile gases so that
a bright fire burns on the grate; A² an arched opening connecting the rear ends
of the furnaces; A³ is a swing-gate controlling the front connections between
the furnaces A and A¹ with the combustion-chamber A4 the arch A5 of which
extends over the width of the two furnaces; A the bridge-wall at the end of the
grate A7. Each furnace is provided with an ash-pit door A8 and a firing-door A³.
The furnaces and the combustion-chamber may be enclosed, and in the preferred
form are enclosed, by the cellular casing A10 consisting of a series of hollow
sections divided by vertical partitions pierced with openings to connect the adjoin-
ing cells, the several sections are connected by the pipes A"A" and water is
supplied to the cellular casing to be heated and conducted from the casing to a
tank, or pump, to be delivered to the boiler. The vertical tubular boiler B has
its lower tube sheet at or nearly at a level with the grate surface of the furnaces,
and the combustion-chamber A4 connects with the flame-chamber A2 under the
tubular boiler by the drop-flue A13,-the transverse wall, supported on the arch A¹
and the wall A, prevents direct access to the shell of the vertical tubular boiler
in the form shown in the drawings, but this construction may be modified so as
to leave an open space around the lower part of the vertical boiler B, closed in at
a point below the water-level in the boiler,- -a method well known and generally
practiced in steam-boiler construction.
The vertical tubular boiler B is provided with the horizontal cylinder B₁ extending
through the combustion-chamber A to the front, the pipe 12 extends from the
cylinder B¹ downward through the drop-flue A13 to the mud-drum 133, and within
the pipe B2 is placed a pipe surmounted with the scum-collector B4,--the front
end of the cylinder B' is provided with the head-fitting B5 and is connected by
the pipe 136, extending diagonally on each side, with the manifolds B-B, and
these manifolds are connected by the pipes B38-138 with the manifolds B-B³‚—
the water-tubes 310-B10 extend from the manifolds B7-B to the manifolds
BB and from these the water-tubes B12 B12 extend downward to the
manifolds B-1313 each connected with a mud-trap B¹.
From the manifolds B-B9 extend the water-tubes 1315-B15 through the length
f the furnaces A and A',-the portions of these water-tubes beyond the bridge-wall
re bent and connect by means of the tubes B16B16 with the manifolds B17-B17
onnected each by means of a suitable connecting-pipe with the manifolds B13—-B¹³¸

page_text: and these manifolds 1313_1313 are connected by the pipes 1318 with the mud-drum B
secured to the lower end of the cylinder B20 extending downward from the central
portion of the lower tube-sheet of the vertical tubular boiler B. The feed-water
is supplied to the steam-generator through the pipe 1321 which extends through the
central portion of the vertical tubular boiler B and through the circulating tube B
in the cylindrical projection B20 and ends in a conical nozzle or other suitable
distributor within the mud-drum B19.
To secure convenient access to the mud-drums and connections, the souterrain C
is built below the floor-level of the boiler-house, the well C and door C³ connect
with the souterrain C which is of such height and dimension as will enable a
person to enter and make any required inspection or repairs. The manifolds
Bu B may be conveniently reached by removing the section C3 which is discon-
nected from the cellular casing A10. The manifolds B and B are reached by
opening the door Cover the fire-doors A-A in the front of the generator. The
manifolds are provided with the usual hand-hole covers opposite each of the
water-tubes.
To enable others skilled in the art to use my invention, I will describe the
operation of the same more fully.
Before lighting the fire in the improved steam-generator the boiler is to be filled
with water until the horizontal cylinder B¹ is, at least, half full and the water-
line is maintained above the horizontal center of the cylinder B¹. The fire is
first lighted in one of the two furnaces A or A¹ and the products of combustion
are passed through the other furnace into the combustion-chamber and from this
through the drop-flue and the tubes of the vertical boiler to the chimney, as
soon as the fire burns brightly the firing and ash-pit doors of this furnace are
closed, the other furnace is lighted and the smoke and gases of this furnace are
made to pass by the adjustment of the gate A³ through the opening A2 and over
the fire of the first furnace. This alternate firing of one furnace after the other
and the passing of the products of combustion of one furnace over the incandescent
fire in the other furnace is continued. When the brick-work has been thoroughly
heated the arches over the furnace that is being supplied with fuel greatly facilitate
the combustion of the fuel and the combustion of the volatile gases disengaged
by the combustion of the fuel. These gases pass from the furnace in which they
are generated through the arched-opening A2 into the other furnace in which a
bright incandescent fire is burning and the arch of which is highly heated. The
gases are by this passage from one furnace to the other thoroughly mixed while
they are maintained at the high temperature required for combustion. In this
condition the gases pass upward into the combustion-chamber A¹ the cross-
sectional area of which is about three times the cross-sectional area of the furnace,
the gases expand and being surrounded by the heated brick-work are thoroughly
consumed. The heated products of combustion descend to the flame-chamber Aiz
and pass upward through' the tubes of the vertical tubular boiler to the uptake and
chimney, neither soot or smoke enter the tubes of the boiler and the fine ashes
usually carried into the tubes are precipitated in the combustion-chamber and
flame-chamber, owing to their great cross-sectional area and slower movement of
'the gases.
The water heated in the cellular casing under atmospheric pressure by the
heat carried through the brick-work into the casing is forced by a pump through
the feed-pipe into the mud-drum B9 from which it flows into the two mani-
folds B3 313 and from these into the manifolds B B and, ascending through
the water-tubes B15b5 extending through the two iurnaces A and A¹, is delivered
highly-heated through the manifolds B-139 137-B and the connecting pipes into
the front end of the horizontal cylinder 11 where the liberation of the steam is
facilitated by the extended water surface the level of which is mairtained by
the connection of the horizontal cylinder with the vertical steam-boiler B and the
pipe 1 through which the surplus water is conveyed to the mud-drum B³ the
lower end of which is connected by a large pipe with the mud-drum B19 under the

page_text: vertical steam-boiler B, thereby securing the rapid circulation of the water through
the water-tubes, the liberation of the steam and the maintenance of a reliable
water-level. The impurities are gathered by the scum-collector B and carried
to the mud-drum B.
A portion of the water ascends from the manifolds BB3 through the vertical
water-tubes B2-1313 to the manifolds B and thence through the water-tubes B10
to the manifolds B7 and enters the front end of the horizontal cylinder B' where
the steam is separated from the water, the water-level maintained and the rapid
circulation of the water secured in the manner above described with reference
to the water-tubes B. Circulation of the water is maintained in the vertical
tubular steam-boiler B by means of the circulating tube B-the annular space
forming ascending currents while the descending currents pass down the tube B2
to the mud-drum. The horizontal cylinder B has large steam and water col.
nections with the boiler B. The steam generated passes freely to the
boiler and the large body of water in the boiler maintains the normal water-level
in the horizontal cylinder although the same is exposed to the first action of the
heat.
Having now particularly described and ascertained the nature of my said inven
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
-
Claim 1. In combination with a steam-boiler, a furnace divided by a partition
into two separate firing-chambers, a flame-chamber in the rear of and connecting
the two firing-chambers, and a draught-opening in the front end of the firing-
chamber controlled by a gate, whereby the products of combustion from one
firing-chamber are made to pass through the flame-chamber and over the fire in
the other firing-chamber, as described.
2. In combination with a steam-boiler, a furnace enclosed by walls of some
refractory material, a partition dividing the furnace into two separate firing-
chambers, a flame-chamber in the rear of and connecting the two firing-chambers,
and a draught-opening in the front end of the firing-chambers controlled by a
gate, whereby the products of combustion from one firing-chamber are made to
pass through the Hame-chamber and through the other firing-chamber before
entering the tubes of the boiler, as described.
3. In a steam-generator, the combination with the steam-boiler, of a furnace
having two separate firing-chambers, a flame-chamber in the rear of and connecting
the two firing-chambers, a draught-opening controlled by a gate, and a combustion
chamber; the whole enclosed by fire-brick, whereby the products of combustion
from one firing-chamber are made to pass through the flame-chamber, through
and over the fire in the other firing-chamber and through the combustion chamber
before they enter the tubes of the steam-boiler, as described.
4. In combination, a steam-boiler, a furnace divided by a partition into two
separate firing-chambers, a flame-chamber connecting the rear of the two firing-
chambers, a draught-opening at the front end of the firing-chambers, a combustion-
chamber, and a cellular water-jacket enclosing the furnace, whereby the more
perfect combustion of the fuel is secured before the products of combustion enter
he tubes of the boiler and radiated heat is transmitted by the brick lining to the
vater in the jacket, as described.
5. In combination, a steam-boiler, a brick-enclosed furnace divided by a partition
nto two firing-chambers connected at the rear by a flame-chamber and at the front
y a draught-opening with a combustion-chamber, of a series of water-tubes,
xtending through the furnace, connected with the mud-drum of the boiler and
ith the boiler, whereby the more perfect combustion of the fuel is secured before
he products of combustion enter the flues of the boiler and the radiated heat is
cally utilized by the water-tubes, as described.
6. In combination with a steam-boiler and a furnace divided by a partition into
wo separate firing-chambers adapted to be alternately fired, of two separate

page_text: sections of water-tubes, one section for each firing-chamber, each section connected
with the mud-drum below. the furnace and with the boiler above the furnace,
whereby the sections may adjust themselves to variations in temperature, as
described.
7. In a steam-generator, the combination with a vertical tubular boiler having
a central water-column connected with a mud-drum at its lower end, of the trans-
verse chamber B6 provided with the mud-drums B7-B7, a series of water-tubes 1310
and 12, connections between the water-tubes, the chamber B6 and the boiler, and
a furnace located on one side of the central water column of the boiler, whereby
the heat of the fire is exerted on the water-tubes before the products of combus-
tion enter the flues of the boiler and the efficiency of the boiler increased, as
described.
8. In a steam-generator, the combination with the vertical tubular boiler B,
the water-column B³, the circulating tube B5 and the mud-drum B4, of the feed-
water pipe B7 and the rose B18 connected with the feed-water pipe below the ash-pit,
whereby the feed-water is sprayed into the mud-drum and the precipitation of
impurities facilitated, as described.
9. In combination, a vertical tubular steam-generator, a central water-column
extending from the lower tube-sheet downward, a circulating tube within the
central water-column, a mud-drum at the bottom of the central water-column, a
feed-water pipe extending from the top of the boiler downward and terminating
in the mud-drum, a transverse chamber connected with the mud-drum and provided
with auxiliary mud-drums, a series of water-tubes connected with the transverse
chamber, with the boiler and with the mud-drums of the transverse chamber, and
a furnace divided by a partition into two firing-chambers and adapted to be
alternately fired, as described.
10. In a steam-generator, the combination of the following instrumentalities; a
furnace divided by a partition into two arched firing-chambers, a semi-circular
arched flame-chamber connecting the rear of the two firing-chambers, an arched
combustion-chamber above and extending across the width of the firing-chambers
a draught-opening, controlled by a gate, connecting the firing-chambers with the
combustion-chamber, a cellular water-jacket enclosing the furnace structure, and
a steam-boiler connected with the combustion-chamber, whereby the fuel is con-
sumed within spaces surrounded by fire-brick and the products of combustion
passed through the tubes of the steam-boiler, as described.
11. In a steam-generator, the combination with the vertical tubular steam-
boiler, of two furnaces placed side by side, said furnaces extending above the
lower end of the tubular boiler, brick-work enclosing the furnaces, a combustion-
chamber above the furnaces, and a drop-flue connecting the combustion-chamber
with the space under the vertical tubular boiler; whereby the fuel is consumed
in brick-enclosed furnaces and the products of combustion pass through the
combustion-chamber and downward under the tubular boiler, as described.
12. In a steam-generator, the combination with the vertical tubular steam-
boiler, of two brick-enclosed furnaces located above the lower end of the tubular
boiler and connected so as to be alternately fired, a combustion-chamber above
the furnaces, a cylinder connected with the tubular boiler at the water line and
extending through the combustion-chamber, and a flue connecting the combustion-
chamber with the space under the tubular boiler; whereby the fuel is consumed
in brick-enclosed furnaces, soot and ashes are retained and the heat is made to
enter the tubes of the vertical boiler, as described.
13. In a steam-generator, the combination with the vertical tubular steam-boiler,
the horizontal cylindrical extension and the furnaces, of the series of water-
tubes B10, B1a and 1315 connected with the boiler below the furnaces and with the
horizontal cylinder, whereby the circulation of the water in the boiler, the water-
tubes and the horizontal cylinder and the separation of the steam are facilitated.
14. In a steam-generator, the combination with two furnaces placed side by
side and connected, as described, so that they may be alternately fired, a com-

page_text: bustion-chamber above the furnaces, said furnaces and combustion-chamber
enclosed in brick-work, a vertical tubular boiler located in the rear of the furnaces,
the tube-sheet of which is below the normal level of the fuel in the furnaces, a
flame-chamber below the vertical tubular boiler, a drop-flue connecting the com-
bustion-chamber with the flame-chamber, and a cellular casing, enclosing the
furnace portion of the steam-generator, provided with water supply and con-
necting pipes, whereby the part of the heat held back in the combustion-chamber
and transmitted through the brick-work is utilized to heat the feed-water, as
described.
Dated this 28th day of M
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.