Improvements in Furnaces for Roasting, Smelting, and Separating Refractory and other Ores.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvements in Furnaces for Roasting, Smelting, and Separating
Refractory and other Ores.
I, JOHN L. HOPPER, of Sarcoxie, in the County of Jasper, and State of
Missouri, United States of America, Miner, 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 :-
This invention has relation to improvements in furnaces for roasting, smelting
and separating refractory and other ores, and the novelty will be fully understood
from the following description and claims when taken in connection with the
accompanying drawings, in which:
Fig. 1 is a front elevation of my improved furnace showing parts in section and
parts broken away.
Fig. 2 is a vertical, longitudinal sectional view taken in the plane indicated by the
dotted line x-x on Fig. 1.
Fig. 3 is a plan view with one of the arches or roofs of the smelting ovens broken
away and one of the doors partly raised, and
Fig. 4 is a vertical, transverse sectional view taken through the hot air chamber
and Hue chamber above the same at the point indicated by dotted line y-y on
Fig. 3.
Referring by letter to said drawings, A indicates the masonry of a twin furnace.
This furnace is provided with doors a, in its front as shown and suitable grate
bars b, forming a fire-box, which may be of the ordinary or any approved con-
struction, and these fire-boxes or chambers c, are divided by a vertical central
partition wall B, which extends from the front of the furnace to a sufficient distance
rearwardly as shown.
C indicates a cold air or draft passage formed beneath the fire grate.
Arranged above each fire chamber or fire-box is a roasting oven D, provided
with an arched top as shown, and the floor of these ovens are formed with roasting
plates d. These plates are made of pure fire clay and are arranged above the fire
chambers of the furnaces and pitched or inclined towards their outer ends as better
shown in Fig. 2 of the drawings. These roasting plates which form the roof of a
furnace fire chamber are extended beyond the front wall of the furnaces as shown
e, for a purpose which will be presently explained.
at
E indicates a hot air chamber designed to receive the smoke and particles of
combustion from the furnaces. This chamber is arranged in rear of the fire-boxes
and bridge-wall of the furnaces and communicates both of said furnaces with the
roasting oven above. This hot air chamber which opens from the respective
furnaces into the roasting or smelting ovens, are provided with damper plates or
gates f. These gates or dampers are hinged or pivoted in the top of the hot air
chamber E so that communication may be established between the furnace below
and the oven above or closed as desired.
It will be observed that the masonry in the rear of the furnace is of a less height
than the side walls in front, and I arrange upon this rear wall F, a chamber G,
which I shall denominate a smoke chamber. This smoke chamber is divided into
two compartments one for each of the roasting ovens and are arranged respectively
in rear of said ovens and in communication therewith. This smoke chamber is
preferably constructed of metal and has double walls as shown at g, a double wall
being also formed between the compartments of said chamber as shown at H.
The dampers or grates f, are journalled in one of the side walls of each compart-
ment of the smoke chamber and one of the division walls H, and each gate or
damper is provided with a handle I which extends on the outside of the casing so

page_text: that said dampers may be opened or closed by an attendant and these handles I,
are preferably provided with a flat spring h, designed to press against the wall of
the casing so as to hold the dampers or gates in the desired position placed by the
attendant.
These smoke chambers are each covered by a door K which are hinged to the
double walled partition H separating said chambers and are designed to normally
close the chambers and consequently the roasting ovens from the open atmosphere.
These fall doors K are preferably formed of a double thickness as shown, so as to
resist the action of intense heat with which they come in contact.
In operation it will be seen that the smoke and particles of combustion as they
leave the fire-box of the furnace and enter the hot air chambers E will burn as a
fuel therein, while such particles as remain unconsumed will pass to the compart-
ments G above and are thence directed into the oven, and will burn as gases thereby
economizing the fuel and obtaining a very great heat from a small amount of coal
or other fuel.
L indicates a cross-beam arranged in the front of the furnaces as shown, and
M indicates the bridge-wall of the furnaces upon which bars are placed and arranged
longitudinally to support the roasting plates of the smelting or roasting ovens.
These roasting plates extend forwardly over the front wall of the furnaces a
sufficient distance to receive beneath them suitable cars or receptacles for the metal
which has been smelted, and these projected plates serve the additional function of
a support for the breeching which is built thereon. This breeching N, com-
municates with the ovens D at one end and is divided by a wall m, upon the top of
which is a damper P, so arranged as to open and close the branched stack or smoke
pipe Q, or either passage thereof as desired. The wall separating the passages of
this stack between the ovens is preferably a double wall and the damper is provided
with a handle R, which extends upon the outer side of the breeching within convenient
reach of an attendant, and a ratchet plate or rack S, is also provided on the outer
side of the breeching so as to hold the arm or handle of the damper in the desired
position.
n,
By reference to Fig. 1 of the drawings, it will be seen that the lateral vertical
walls
of the breeching extend slightly beyond the lateral edges of the roasting
plates so that the metal as it is melted may be conducted beneath said walls and
into any suitable receptacle placed or brought beneath the projected ends of said
plates.
These roaster plates which pitch toward one end have a groove or channel with
a rounded base extending along the edges of their upper sides and these grooves or
channels communicate with a transverse channel or flume p, leading to the side edges
of said plates at the points where the walls n, of the breeching overlap them.
T indicates ribs or flanges arranged on the upper sides of the roasting plates and
along the side walls of the ovens. These flanges or ribs are fixed to the plates by
being molded thereon and burned therein and the ribs and plates are highly glazed
before burning so as to give them a perfect smooth surface and thereby allow any
matter which has been smelted to run freely as fast as melted and be received into
clay pans or other suitable receptacles from the flumes
p.
While I have shown and described my apparatus as having two fire chambers or
furnaces and two roasting ovens above them, yet I do not wish to be confined to
that number as any suitable number might be employed and arranged side by side
in pairs.
In operation the ore to be smelted is fed into the oven through the smoke
chambers G, the gates or dampers f, having been previously shut down. Fuel is
fed into the furnaces in the ordinary manner and as fire is started the dampers fare
raised when the smoke and products of combustion, leaving the furnaces will pass
into the hot air chambers E, and the heated gas from the furnaces which is directed
against the under side of the roasting plates which form the roof of the furnaces is
also directed into the hot-air chamber and thence through the smoke chambers G
above into the roasting ovens. Such smoke and particles of combustion as they

page_text: pass through the hot air chamber are in a measure consumed forming a further
heating for the roasting ovens; and the gases as they arise in the chamber G are
also consumed and fed to the ovens in a suitable manner when such particles pass
out through the breeching and into the stack.
As the ore has been smelted and drawn from the ovens the fall-doors may be
raised and more ore fed in and in order that the operation may be continuous I
close but one of the dampers f, at a time, for instance by closing one of the dampers
the smoke and particles of combustion will be directed from both furnaces into the
hot air chamber and from thence into but one of the ovens, the other having been
shut off from communication with the furnace below by the closing of the damper,
when by manipulating the lever or handle R in the breeching the damper P will
close off the stack from communication with the oven which is being filled with
ore. In this way the operation may be continued indefinitely and while the heat
from the fuel in the furnace will act upon the roasting plates, yet the flame and
particles of combustion will not be allowed to pass into the oven being filled with ore.
As the ore is smelted and the melted metal runs out in the flumes p, I design
providing a track beneath the projected smelting plates so that cars may be drawn
in beneath the plates containing a suitable liquid bath, so that the metal may pour
into the bath directly from the ovens, and as a bath for softening and subduing
refractory ore I design using a composition of salt, saltpetre and water.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
-
1. A roasting and smelting furnace having two fire chambers, in combination
with a hot air chamber connecting said fire chambers at one end, ovens arranged
above said fire chambers and smoke chambers separated from each other and
communicating with the ovens and hot air chamber beneath and dampers for closing
communication between the hot air chambers and ovens the stack and flues leading
thereto, substantially as specified.
2. A roasting and smelting furnace having two fire chambers, in combination
with two roasting ovens arranged above said fire chambers, a hot air chamber
connecting the fire chambers at one end, dampers for opening and closing com-
munication between the fire chambers and ovens at one end and a breeching
arranged at the opposite ends of the ovens, a stack on the breeching, flues
connecting the stack to the ovens and a damper in the stack for closing the latter
from one of the ovens, substantially as specified.
3. A roasting, and smelting furnace having two fire chambers, in combination
with a hot air chamber arranged in the rear thereof and in communication therewith,
a smoke chamber arranged above the hot air chamber and divided into two com-
partments, roasting ovens arranged above the fire chambers and communicating
respectively with the compartments of the smoke chambers, dampers arranged in
the top of the hot air chambers so as to open and close communication between one
or both of the ovens and one or both of the fire chambers, fall-doors arranged in
the tops of the respective smoke chambers for closing the same and a breeching
arranged upon the projected ends of the smelting plates and carrying a damper to
open and close communication with one or both of the ovens substantially as
specified.
4. A roasting and smelting furnace having a smelting plate projected at one end
beyond the furnace so as to receive beneath said plate a suitable receptacle, the
roasting plate having a flume arranged transversely as shown on the projected parts
of the plates for conducting the melted metal and arranged on a pitch or incline,
substantially as specified.
5. The combination with the furuace having the two fire chambers, of the hot
air chamber arranged at one end thereof and in communication with the fire
chambers, the smoke chambers divided into two compartments by the double walled
partition and the double wall surrounding said smoke chambers, the dampers

page_text: arranged on the top of the hot air chambers, the fall-doors arranged on the
top of the smoke chambers, the roasting ovens communicating with the smoke
chambers and having smelting plates arranged on a pitch or incline and pro-
jected beyond one end of the furnace and also having flumes and the breeching
arranged on the projected portion of the roasting plates with its side walls pro-
jecting over the lateral edges of said plates and a damper arranged in the breeching,
substantially as specified.
6. A roasting and smelting furnace having its roasting plates projected beyond
the furnace and arranged on a pitch and also having a flume in their upper sides,
in combination with a breeching arranged on the projected portions of said plates
and having its lateral walls overlapping the side edges of said roasting plates,
substantially as specified.
Dated this 10th day of November 1891.
W. P. THOMPSON & BOULT,
Agents for the Applicant.