New Combined Smelting and Reverberatory Furnace and Apparatus for Catching the Dust and Condensing the Fumes from the Furnace.
Year: 1889

page_text: Date of Application, 16th Dec., 1889-Accepted, 25th Jan., 1890
A
COMPLETE SPECIFICATION.
New Combined Smelting and Reverberatory Furnace and
Apparatus for Catching the Dust and Condensing the Fumes
from the Furnace.
1, ROBERT FLORENT NENNINGER, Engineer, of the City of Newark, County
of Essex, and State of New Jersey, United States of America do hereby
declare the nature of this 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 relates first to a new form of furnace designed more especially for
the treatment of fine ores, sweepings, concentrates, &c., and second, to an apparatus
for catching the dust and condensing the fumes from said furnace.
Said
The smelting furnace and reverberatory furnace have a hearth in common.
smelting furnace has two sets of tuyeres at different levels and is provided with
means for causing a downward draft. The hot gases are subsequently conducted
through the reverberatory furnace flue and over the molten material, and thence pass
to the condensing apparatus.
In the accompanying drawings, Fig. 1 is a side elevation and partial section of
the furnace. Fig. 2 is a front elevation. Fig. 3 is a vertical section and Fig. 4 is
a front elevation and partial section on line Y Y of Fig. 2. Fig. 5 is a side elevation
and partial section of the condenser, and Fig. 6 is a partial top view and
horizontal section on the line X X of Fig. 5. Similar letters of reference indicate
like parts.
The body of the furnace consists of two principal parts; a smelting furnace and
a reverberatory furnace, these being combined in a single structure, and having the
metal hearth and flue in common. The shaft of the blast furnace consists of a lower
portion or smelting chamber 1, and an upper portion or shell, 2, and is lined with
fire brick. The lower portion of the shaft rests upon a fire brick foundation which
also forms the side walls of the metal hearth or crucible 3, Fig. 3, of the reverberatory
furnace 4. The upper portion 2 of the shaft is a square wrought iron shell' supported
by brackets 40 upon the columns 9, which in turn rest upon the supports 41.
upper part of said shell is fastened to the charging floor 31. Surrounding the lower
portion of the shaft are four non-communicating water jackets, 5, 6, 7, 8, resting
upon the walls and arch of the furnace 4, and bound together by the bars 10 which
pass through straps 11 on the sides of jackets and are locked together as shown in
Fig. 1.
The
12 is a water pipe leading from any suitable source of supply. It communicates
with each jacket by a tube, as 13. Each tube extends downwardly nearly to the
bottom of the jacket, and delivers water therein. In the pipe 12 are valves, as 14,
by which the supply to each tube 13 and hence to each jacket, may be regulated.
From the upper portion of each jacket extends a water pipe 15, which delivers into
a trough 16 and from said trough a pipe 17 may lead to the condenser hereinafter
described.
It will be apparent from the foregoing, that the water from the supply pipe 12
constantly circulates through the jackets and finally escapes at the pipe 17.
18 is an air trunk leading from a blower or other source of air supply and
having branches 19 supported on the columns 9 on each side of the upper portion 2
of the shaft. Extending from each branch 19, are two lateral pipes 20, which enter
cylindrical chambers 21. From the lower extremity of each chamber, extends down-
wardly a tube 22, and this tube enters the side of the inclined tube 23, which
communicates with a tuyere which passes through the water jacket and enters the
lower portion 1 of the shaft, Fig. 1. There are four of these tuyeres two on each side

page_text: of the shaft, at 24, 25, 26 and 27. The outer end of each inclined tube 23 is
plugged or provided with a removable cover 28, so that a rod can be thrust down
through the tuyere to clear out obstructions.
Extending downward into each chamber 21 and tube 22, and terminating at about
the point of entrance of said last mentioned tube, is a charging pipe 29, which pipe
is carried upwardly and terminates in a funnel 30 set in the charging floor 31.
There are, therefore, two funnels 30 located on each side of the hopper 32, which forms
the charging opening of the shaft. Resting upon the charging floor and extending
over the funnels are bars or. plates 33. The ends of said bars receive the threaded
stems 34 of the double cone valves 35, Fig. 1. A valve 35 is arranged in each funnel 30,
and closes the opening of the latter into the pipe 29. Extending downward through
said pipe 29 and secured to the lower apex of each valve 35, is a pointed metal rod 36.
At the upper extremity of each valve stem 34, is a hand wheel 37. The charging
hopper 32 is provided with the usual bell cover 38.
It will be seen that from the above described construction, the tuyeres 24, 25, 26
and 27 act both as blast and charging openings. Fine ores, sweepings, tailings,
concentrates, etc., are placed in the funnels 30 and the valves 35 being opened,
descend through the pipes 29 and enter the tuyere pipes 23. Valves 39 in the pipes 20
then being also opened, the blast enters said pipes, meets said fine material as it falls
from the charging pipes 29 and drives it through the pipes 23 and tuyeres 24, 25, 26
and 27 into the shaft.
From each branch 19 of the air trunk, a vertical pipe 41 communicates with
branches 42, which lead to the lower tuyeres, 43, 44, 45 and 46, these tuyeres also
passing through the water jackets. Valves 47 are provided in the pipes 42. Eight
tuyeres, therefore, enter the shaft, four (24, 25, 26 and 27) being disposed above the
remaining set of four, 43, 44, 45 and 46.
The reverberatory hearth is enclosed in cast iron plates 48, 49, 50, 51, 52 and 53,
and the plate 48* which is fastened to the front plates, 48, 49. In said plates are
five tap openings provided with slag spouts 55, 56 and 57, a matte spout 58 and a metal
spout 59.
As shown in Fig. 3, the matte tap 58 is at a higher level than the metal
tap 59.
The inside of the hearth walls and bottom has a lining preferably composed of a
mixture of powdered limestone and fire clay, which, after being moistened, is firmly
rammed in place. Above the hearth is an arch 60. Extending down from the branch 19
of the air trunk are pipes 61, which open into the hearth chamber through the side
walls, as shown at 62, Fig. 3. The gases from the hearth are led to the condenser
from the opening at 63.
Various smelting processes can be carried into effect in the apparatus above
described, one of which will be now specified in order to exhibit its operation.
A coke fire is started in the bottom of the shaft. When incandescent, a quantity
of metallic lead is thrown in, until the hearth is filled with melted metal above the
tap 58, as shown in Fig. 3. Coke is then put into the shaft up to the level of the
charging floor, and as soon as the charge becomes incandescent up to the upper set
of tuyeres the furnace is ready to receive its ore and blast. Let it be supposed
that a mixture of sweepings and ore concentrates (pyrites) pulverized and combined
with proper fluxes is to be treated.
A weighed quantity of the mixture is placed
in the funnels 30, and the valves 35 being opened and the blast turned on, this is
projected in the manner already described through the tuyeres 24 to 27 into the
incandescent coke in the shaft. Fusion immediately begins and before the mass
reaches the lower set of tuyeres, 43 to 46, it is in a molten state. At said lower
tuyeres the liquefaction of the mixture is completed and the separation of the
metal, matte and slag takes place; while the air furnished by said tuyeres causes
a thorough combustion of the gases. In this way, the carbonic oxide due to the
passage of the carbonic acid gas through the large body of incandescent coke
between the two sets of tuyeres, is re-converted into carbonic acid and a large saving 5
of fuel effected.

page_text: This operation is carried on until sufficient matte is formed in the reverberatory
hearth above the tap opening at 58, Fig. 3, and then air is admitted into said
matte through the blast openings at 62. The air coming in contact with iron matte
(the watte supposed contains the reducible metals, gold, silver, copper, &c.),
oxidizes the sulphur and iron, and the sulphur may be carried off into a condenser
as sulphurous acid fumes while the iron is absorbed by the slag as oxide (the
slag being silicious for this purpose). The reducible metals then collect in the
lead bath at the bottom of the hearth. The time of tapping the rich lead at
the spout 59, will depend upon the richness of the material smelted. The slag and
matte are drawn off from the remaininng spouts.
It is, of course, to be understood the use of the furnace is not limited as herein
described, in which fine ores are charged through the upper tuyeres, because obviously
the charge can be inserted in the shaft through the hopper in the usual way and
the valves 35 being closed air may be delivered through the tuyeres 24 to 27. Where
it is desired to restrict the furnace to such employment, the chambers 21 may be
permanently closed above, and the funnels 30, tubes 29 and associated parts for
charging in ore dispensel with, thus saving expense in construction. So also instead
of delivering blast through the air trunk 18, any suitable exhausting apparatus
may be applied to draw air and fumes out at the flue opening 63.
Referring now to Figs. 5 and 6, A is a shaft in the fire-brick wall B in which are
numerous openings C. At the upper portion of the shaft A is a wrought iron
stack D, which rests on the cover plate E. Surrounding the wall B is a fire-brick
wall F; so that between said walls F and B, there is an annular chamber G. It
will be observed that the plate E covers the top of the annular chamber G, and that
the top of the shaft. A just below the plate E is slightly flared or enlarged. The
bottom of the annular chamber G forms a gutter which is downwardly inclined to the
point H where it meets a cistern I. In said cistern is arranged a filter J, and above
said filter and communicating therewith is a gutter K.
Lis an arched passage
through the walls F and B and chamber G communicating with the interior of
shaft A. This passage is closed by a door or doors M. In the upper part of the
stack D there enters a steam pipe N, which communicates with an exhauster O in
said stack which exhauster is supported by brackets P. This exhauster is of well-
known form, and consists of a series of cylinders of increasing diameter connected
together. Its object and purpose when the steam is turned into it, is to produce an
upward draught in the stack, in a manner well known and not necessary to be
described. In the wall F there is an opening 63 which communicates with the annular
chamber G and with the reverberatory furnace 4, Figs. 1 to 4. The stack D
extends above the charging floor Q, and in the side of said stack and having its
mouth on a level with said floor Q, is a charging shoot R. S is a pipe communicating
with any suitable source of water supply, and having depending from it numerous
branch pipes T and U, which are provided at their lower ends with roses or sprinklers.
The pipes U enter the flared space in the shaft A; the pipes T enter the annular
chamber G.
up
to the
The operation of the apparatus is as follows: The shaft A is filled with coke
level of the charging floor, the fumes entering at the opening 63, and there pass into the
cbamber G, and are met by a shower of water descending from the pipes T. This
water takes up the dust in the fumes, and washes the same into the gutter at the
bottom of said chamber, the outflow going into the cistern I, then rises through the
filter J, which prevents dust from passing, and runs off into the gutter K. The dust
is afterwards removed through any convenient opening from the cistern L. The fumes
thus freed from dust enter the stack A through the opening C, and are condensed in
the coke therein, which is kept wet by water percolating through said coke from the
pipes U. Draught through the apparatus is produced by the exhauster O. The coke
after use is removed from the shaft A through the door M.

page_text: 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 :-
1. The combined smelting and reverberatory furnace constructed and arranged
substantially as hereinbefore set forth.
2: The condenser for furnace fumes, &c., constructed and arranged substantially
as herein before set forth.
3. The combined smelting and reverberatory furnace herein before described in
combination with the condensing apparatus receiving fumes, &c., from said furnace,
all substantially as set forth.
4. The combination in a smelting furnace containing a hearth, a smelting chamber
above said hearth, and a shell or shaft above said smelting chamber: said chamber
having two air delivery openings disposed one higher than the other, substantially
as described.
5. A metallurgical furnace embodying a smelting stack or shaft, a reverberatory
furnace and a hearth common to both.
6. In combination with a reverberatory furnace 4. having the hearth 3, the smelting
shaft 1, 2, having air inlet openings at different heights and means for forcing an
air current through said openings downward through said shaft and over said hearth,
substantially as described.
7. A metallurgical furnace embodying a smelting stack or shaft, a reverberatory
furnace and a hearth common to both, the said reverberatory furnace being provided
with a means of introducing air below the charge on the hearth.
8. A reverberatory furnace having a hearth or crucible and four openings com-
municating therewith, namely, a metal tap, a matte tap, an air inlet and a slag tap;
the said openings being disposed in the side of said hearth, and one lower than the
other in the order named, substantially as described.
9. In combination with a smelting furnace, an air supply conduit entering through
the wall thereof, and a charging conduit terminating within said air conduit, sub-
stantially as described.
10. In combination with a smelting shaft 1, the air supply pipe 23, charge supply
pipe 29 terminating within said air pipe, funnel 30 in pipe 29, conical valve 35 in said
funnel opening, and rod 36 attached to said valve and enclosed in said pipe 29,
substantially as described.
11. The combination of the reverberatory furnace 4 having the hearth 3, the
smelting shaft 1, 2, above and opening into said furnace, the air supply trunk 19,
tuyeres 25 and communicating with the interior of said shaft at different elevations
and with said air trunk 19 and the pipe 61 communicating with the interior of said
reverberatory furnace and with said trunk 19 and terminating above the bottom of
said hearth substantially as described.
12. In combination with a smelting shaft 1, the air supply pipe 23 and the charge
supply pipe 29 terminating within said air pipe, substantially as described.
13. The combination of the shaft A having lateral openings, the surrounding
annular chamber G having an inlet opening in its outer wall for fumes to be con-
densed, and pipes communicating with a source of water supply and with the upper
portions of said shaft A and said chamber G substantially as described.
Dated this Fourteenth day of December 1889.
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow, Agents.