IMPROVED MEANS FOR UTILIZING THE WASTE HEAT OF CUPOLA FURNACES.
Year: 1877

page_text: LETTERS PATENT to Alexander Wilson, of Sheffield, in the County of York,
for the Invention of "IMPROVED MEANS FOR UTILIZING THE WASTE HEAT
OF CUPOLA FURNACES.".
Sealed the 31st July 1877, and dated the 14th February 1877.
PROVISIONAL SPECIFICATION left by the said Alexander Wilson at the
Office of the Commissioners of Patents on the 14th Febuary 1877.
ALEXANDER WILSON, of Sheffield, in the County of York.
FOR UTILIZING THE WASTE HEAT OF CUPOLA FURNACES."
"IMPROVED MEANS
This Invention relates to means for heating the blast intended to be supplied to
cupolas from the waste gases of such furnaces.
The air-blast heating apparatus for cupolas I propose to modify according to
special cirumstances, but in all cases it will be situate at or near the top of
the furnace and so arranged that an extended heating surface will be presented to
the ascending gases of combustion on their passage to the chimney.
In adapting air heating apparatus to an existing cupola, I form at or near the
top of the furnace an annular chamber of cast iron, the central opening in which
will allow the gases of combustion to pass through. This annular chamber I divide
into two parts by a horizontal partition, and in this partition I form a ring of holes
to receive a series of pendent flanged pipes which are open at their lower ends and
project down through a corresponding series of holes made in the bottom of the
chamber. These holes, which are of somewhat larger diameter, I cover with
pendent pipes closed at their lower ends, and made of sufficient capacity to enclose
the pipes pendent from the partition and leave a free space between them for the
circulation of air.
The upper division of the annular chamber I connect by a pipe with the blast
engine blower or fan, and the lower division I connect by a pipe with the tuyers or
hot blast chamber.
The compressed air supplied to the heating apparatus will pass down the inner
pendent pipes and rise up the external pipes to the lower division of the annular
chamber, taking up the beat which those pipes have extracted from the gases of
combustion circulating around them. The heated air will pass off from the annular
chamber by the hot blast pipe to the tuyers.
Suitable scrapers will be provided for keeping the pendent pipes clear of soot.

page_text: Instead of making the air heating pipes pendent I propose in some cases to
support the same upon a brick cone which projects from the inner face of the
furnace a little above the level of the charging door. This brick door will serve,
when it becomes heated, to ignite the gases which are generated helow. Through
the brick cone there are flues made at the sides in addition to the circular hole in
the centre to allow the ignited gases to circulate freely around all parts of the
heating apparatus above. A convenient arrangement for this heating apparatus is
to provide an upper and a lower tubular ring having nozzles to receive the ends of
vertical coupling pipes; these rings will be connected, the one with the blast engine
blower or fan, and the other with the tuyers'; the blast, entering the top ring will
pass down one pipe and up the next, and so on in succession. The blast could also
be arranged to go up two or three of those pipes and down the same number until
it escapes by means of the downtake from whence it is carried to the tuyers.
Instead of the lower tubular ring a cylindrical chamber with a central flue opening
may be used for the vertical pipes to bed upon, the cylinders being provided with a
set of nozzles for that purpose.
For connecting the pipes with the nozzles I use coupling collars, which, when
loosened, will allow of the removal of the pipes when requiring replacement.
As a modification of this arrangement the air-heating passages may consist of one
or more corrugated tubular castings, with or without a central flue for the passage
upwards of the gases of combustion. This casting if divided into, say, three or more
compartments will allow of the blast entering by means of the uptake going down
one compartment and up the next, and so on, until it leaves the casting by means
of the downtake to go to the tuyers.
When the corrugated tubular casting has no vertical divisions it may be closed at
bottom and carried by the brick cone support before mentioned. At the top it will
be fitted with a flanged hollow casting connected with the uptake leading from the
blast engine blower or fan, and at bottom it will be connected with the downtake
pipe. The flanged casting will rest on the top of the cupola and have openings
therein for the passage outwards of the gases of combustion which will enter a hood
arranged as explained in the next following modification, which is more especially
adapted for small cupolas. In adapting this air heating apparatus to small cupolas
I provide a round hollow casting having a flanged base plate which rests upon the
top of the cupola. In this base plate holes are formed for the passage upwards of
the gases of combustion. The bottom part of the apparatus consists of a semi-
spherical casting, and these two castings are united by upright pipes. The cupola
will in this case be crowned with a wrought-iron hood fitted with a damper to
regulate the draught of the furnace. The blast will enter by means of the uptake
through the hood and into the top casting; it will then pass down the pipes to
the bottom casting and, thence by the downtake to the tuyers.
A further modification of the air heating apparatus for cupolas consists in building
up within the furnace air passages in brick. These may consist of annular chambers
having openings one into the other and extending from the conical support above
the charging hole to the top of the cupola, or they may run vertically or helically.
The annular space enclosed may be divided into two or more compartments, which
are to be brought into connection with the uptake and downtake pipes as before
explained. Transverse metal pipes communicating with the air passages may be
used to intercept the gases of combustion and assist in abstracting the heat there-
from.
For cupola furnaces which are worked in pairs, I propose to stop them off a little
above the level of the feed door and to connect them laterally with a common
chamber to receive the air heating apparatus. This apparatus may be similar in
arrangement to either of those above described, but I prefer a series of syphon
shaped pipes for receiving the air to be heated. These pipes will stand over two
chambers, one of which will be connected with the blast engine blower or fan, and
the other with the tuyers of the two furnaces, or the pipes may be inverted and
depend from the air chambers.

page_text: The waste gases from both furnaces will circulate around the pipes and heat the
blast supplied thereto.
In order to heat the blast preparatory to starting work, and before any waste
gases are available for the purpose, it may be convenient to provide a special fire-
place near the base of the. chamber and to connect it therewith so that the
gases of combustion passing therefrom may circulate around the heating ap-
paratus.
The gases of combustion may pass upwards from this chamber and escape through
a chimney forming an extension thereof, or they may pass down and along a flue
leading to the general chimney of the works.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Wilson in tlie Great Seal Patent Office on the 14th August
1877.
ALEXANDER WILSON, of Sheffield, in the County of York.
FOR UTILIZING THE WASTE HEAT OF CUPOLA FURNACES."
.
IMPROVED MEANS
This Invention relates to means for heating the blast intended to be supplied to
cupolas from the waste gases of such furnaces.
The air blast heating apparatus for cupolas I propose to modify according to
special cirumstances, but in all cases it will be situate and so arranged that an
extended heating surface will be presented to the gases of combustion on their
passage to the chimney.
In the accompanying Drawings I have shown the several arrangements of air
heating apparatus constituting my present Invention, which arrangements I
propose to employ as circumstances may dictate, and as will be hereafter particularly
referred to.
In adapting air heating apparatuses to an existing cupola I employ the arrange-
ment shown in partial sectional elevation at Fig. 1, Sheet I. of the Drawings,
and in sectional plan at Fig. 1a, this section being taken in the line ** of
Fig. 1.
In these Figures A is an annular chamber of cast iron fitted within the furnace
B, B, and at or near the top thereof The central opening a in this chamber A
will permit of the free passage upwards of the gases of combustion. This annular
chamber I divide into two parts by a horizontal partition b, and in this partition I
form a ring of holes to receive a series of pendent flanged pipes c, which are open
at their lower ends and project down through a corresponding series of holes made in
the bottom of the chamber. These holes, which are of somewhat larger diameter than
the pipes c, I cover with pendent pipes d, which are closed at their lower ends and
made of sufficient capacity to enclose the pipes c pendent from the partition and leave
a free space between them for the circulation of air. The upper division of the
annular chamber I connect by a pipe C with the blast engine blower or fan, and
the lower division I connect by a pipe D with the hot blast pipe or chamber com-
municating with the tuyers.
The compressed air supplied to the heating apparatus will pass down the pipe c
and rise up the pipes d to the division of the annular chamber A, taking up the
heat which those pipes have extracted from the gases of combustion circulating
around them. The heated air will pass off from the annular chamber by the hot
blast pipe D to the tuyers.
Suitable scrapers will be provided for keeping the pendent pipes clear of soot.
Instead of making the air heating pipes pendent, I propose in some cases to sup-
port the same upon a brick cone which projects from the inner face of the furnace
a little above the level of the charging door. This arrangement is illustrated in

page_text: the sectional elevation, Fig. 2, of which Fig. 2a is a transverse section taken in the
line of Fig. 2. In these Figures B is the furnace, and B¹ the supporting cone
of brickwork. This brick cone will serve, when it becomes heated, to ignite the
gases which are generated below. Through the brick cone there are vertical flues
in addition to the circular hole in the centre to allow, the ignited gases to circulate
freely around all parts of the heating apparatus above. This heating apparatus
consists of an upper and a lower tubular ring A., A¹, having nozzles a to receive the
ends of vertical coupling pipes a¹. The upper ring A, I connect with the blast
engine blower or fan by the pipe C, and the other with the tuyers by a pipe D.
The blast entering the top ring will pass down one pipe a¹ and up the next, and so
on in succession, or if preferred the blast may be arranged to go up two or three
of those pipes and down the same number until it escapes by means of the down-
take from whence it is carried to the tuyers. Instead of the lower tubular ring a
cylindrical chamber with a central flue opening may be used for the vertical pipes
to bed upon, the cylinder being provided with a set of nozzles for that purpose.
This arrangement is shewn in the sectional elevation, Fig. 3, Fig. 3a being a trans-
verse section taken in the line ** of Fig. 3. E is a cylindrical chamber cast with
a central opening for the passage upwards of the gases of combustion, and ee are
the pipes which connect, as in the former arrangement, with the tubular ring A.
For connecting the pipes with the nozzles in this and also in the last-mentioned
arrangement use coupling collars which, when loosened, will allow of the removal
of the pipes when requiring replacement. The downtake pipe D is fitted to the
lower end of the cylinder E.
As a modification of this arrangement the air heating passages may consist of one
or more corrugated tubular castings, with or without a central flue for the passage
upwards of the gases of combustion.
In Sheet II. of the Drawings Fig. 4 represents a vertical section, and Fig. 4a in
transverse section the air heating apparatus, consisting of a corrugated or tubular
casting A, A, supported on a brick cone B. This casting is closed at its opposite
ends and connected at top with the pipe C leading from the blast, and at bottom
with the pipe D, the corrugations from hollow radial ribs extending from end to
end of the casting, and they present a large heating surface to the ascending gases
of combustion. Fig. 4a shows the casting divided vertically into three compart-
ments by radial dividing walls, and with a central passage through it for the
ascending gases. By making these walls respectively stop short (either at top or
bottom) of the closed ends of the casting, the blast entering by means of the uptake
C will be conducted down one compartment and up the next, and so on, until it
leaves the casting by means of the downtake to go to the tuyeres.
In the sectional elevation, Fig. 5, and in the sectional plan, Fig. 5a, the corrugated
tubular casting is shown without vertical division walls. In this example its closed
bottom rests upon the brick cone support B, and at top it is fitted with a flanged
hollow casting A which is connected with the uptake C; D is the downtake pipe
connected with the casting A at its lower end. The flanged dome-shaped casting,
A¹, rests on the top of the cupola, and in its flange are openings for the passage
outwards of the gases of combustion which enter a hood E that crowns the cupola.
These gases escape from the hood into the air, their exit being controlled by a
damper with which the hood is fitted. In adapting air heating apparatus to small
cupolas I use by preference the arrangement shown in the vertical section Fig. 6,
in transverse section, Fig. 6a, and in top view at Fig. 6b. A, Fig. 6, is a circular
dome-shaped hollow casting, having a flanged base plate, which rests upon the top
of the cupola. In this base plate holes are formed for the passage upwards of the
gases of combustion. The bottom part of the apparatus consists of a semi spherical
casting, A¹; these two castings are provided with nozzles to receive upright pipes a,
which connect them together. The cupola will in this case also be crowned with
a wrought-iron hood, fitted with a damper to regulate the draught of the furnace.
The blast will enter by means of the uptake C through the hood and into the top

page_text: casting;. it will then pass down the pipes a to the bottom casting, and thence by
the downtake D connected therewith to the tuyeres D.
Fig. 7, Sheet III., shows in sectional elevation, and Fig. 7a in transverse section
an arrangement of air heating apparatus composed of pendent syphon pipes A, A,
the opposite ends of which are connected respectively to the chambers A1, A2, which
rests on the top of the cupola. The chamber A¹ is connected with the air com-
pressing engine, and the chamber A² with the tuyeres of the furnace," and they are
cast with flanges which serve to support them on the top of the cupola; these
flanges, like the supporting flanges in Figures 5 and 6, have passages formed therein
for the escape of the gases of combustion which enter the hood E, and may be
controlled in their exit by a damper as before described.
The air may be caused to circulate through the whole system of syphon pipes, or
any portion thereof, as thought desirable, before passing out to the tuyeres, suitable
divisions being made in the chambers A1, A2, for the purpose.
A further modification of the air heating apparatus for cupolas consists in
building up within the furnace, air passages in brick; these may consist of annular
chambers, as shewn in vertical section at Fig. 8, and transverse section at Fig. 8ª,
such chambers having openings one into the other, and extending from the conical
support B above the charging hole B¹ to the top of the cupola, or they may run
vertically or helically. The annular air heating space or spaces A are brought into
connection with the uptake and downtake pipes C and D as before explained. A
modification of the brick air heating tubes is shown in vertical section at Fig. 9,
and in transverse section at Fig. 9. In this example the annular air heating space
A is divided by vertical walls a into two compartments, and these are connected
together by transverse metal pipes, a¹, a², set at right angles to each other, and
crossing the central flue through which the gases of combustion pass in escaping
from the cupola.
These pipes by intercepting the gases of combustion assist in abstracting the
heat therefrom and impart the heat thus obtained to the air admitted to the air
heating chambers A.
For heating the air for cupola furnaces which are worked in pairs I propose to
stop them off a little above the level of the feed door as shown in the sectional
elevation, Fig. 10, Sheet IV., and to connect them laterally with a common chamber
to receive the air heating apparatus. This apparatus may be similar in arrange-
ment to either of those above described, but I prefer the arrangement of syphon-
shaped pipes for receiving the air to be heated shewn in Fig. 10, and in transverse
section at Fig. 10ª.. This arrangement is similar to that described with reference
to Figures 7 and 70, but in this case the pipes instead of being pendent are inverted;
thus the pipes A stand over two chambers, A1, A2, one of which is connected with
the blast engine blower or fan, and the other with the tuyeres of the two
furnaces.
The waste gases from both furnaces will circulate around the pipes and heat the
blast supplied thereto, and the gases of combustion will pass off to the chimney
from the chamber containing the air. heating apparatus. Or instead of the gases of
combustion passing directly into the chimney they may be conducted by a horizontal
flue leading to a distant chimney, as indicated in the sectional elevation, Fig. 11.
In order to heat the blast preparatory to starting work and before any waste
gases are available for the purpose, it may be convenient to provide a special fire-
place near the base of the chamber in which the heating apparatus is situate, and
to connect it with such chamber so that the gases of combustion passing from this
fire-place may circulate around the air heating apparatus.
Having now set forth the nature of my Invention of improvements for utilizing
the waste heat of cupola furnaces, and explained the manner of carrying the
same-into effect, I wish it to be understood that under the above in part recited
Letters Patent I claim,-
First. The arrangements of air heating apparatus above described with reference
to Sheets I., II, and III. of the Drawings.

page_text: Secondly. The means above described with reference to Sheet IV. of the
Drawings for utilizing the waste heat of cupola furnaces when the same are worked
in pairs.
In witness whereof, I, the said Alexander Wilson, have hereunto set my hand
and seal, the Eleventh day of August, in the year of our Lord One thousand
eight hundred and seventy-seven.
ALEX. WILSON. (L.S.)