Improvements in Furnaces for Roasting Ores and the like.
Year: 1899

page_text: Date of Application, 28th Apr., 1899-Accepted, 18th Nov., 1899
Improvements in Furnaces for Roasting Ores and the like.
We, WILLIAM ADOLPH KONEMAN and WILLIAM HENRY HARTLEY, both of
23, Moorfields, in the County of Middlesex, England, Civil and Mining Engineers,
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 follow-
ing statement:-
201
This invention relates to improvements in furnaces for roasting ores and the
like, and has for its object to provide means whereby the distilled products
of the volatile constituents in the ore may be most efficiently removed from the
ore and a thorough degree of oxidation obtained.
This object is accomplished by constructing the furnace in such a manner that
the course of the heating medium through the material treated, can be directed
at will preferably by means of valve-controlled flues which communicate from an
ore chamber to a flame or combustion chamber on the one hand, and a suction
or vacuum chamber on the other.
The volatilised impurities are drawn into the suction chamber, and from thence
to an exhaust passage which has a series of hollow tube-like connections or
pockets opening (in a downward direction) out of its lower side, and has also a
succession of rows of inclined baffle plates, so placed that they tend to arrest
and give a downward motion to any solid particles which may be carried in
the current of the exhaust gases, and gradually divert their course, so that
they are precipitated out of the current into the pockets and tubes. Having
passed through the exhaust passage the gases are drawn through a series of
screens, bagging, or other similar obstructive media, which serve to arrest any
solid particles which are carried by the current and which have escaped the
baffle-plates. The gases are preferably drawn through the furnace by an ex-
hauster so controllable that the draught may be capable of regulation to suit
different kinds, degrees of fineness, and quantities of material treated.
An important feature of this invention is the provision in the flame or com-
bustion chamber of partitions or baffles between the rows of flues or ports for the
purpose of preventing the heating medium from ascending, under the influence
of the strong draught employed, too rapidly and directly from its point of entry
into the flame chamber to its place of exit therefrom, and for causing the heating
medium to pursue such a path that each row or series of ports or flues is enabled
to receive its due share of the hot current.
In the accompanying drawings which illustrate one construction of roasting-
furnace according to this invention.
Figure 1 is a plan of the furnace.
Figure 2 is a view of the same partly in side elevation, and partly in section
on the line 2-2 of Figure 1.
Figure 3 is an end elevation of the same partly in section on the line 3-3
of Figure 1.
Figure 4 is a sectional side elevation of the same on the line 4-4 of
Figure 1; and
Figure 5 is a plan in section on the line 5 5 of Figure 3

page_text: Like letters indicate like parts throughout the drawings.
Fire chambers A with fire bars on which the fire is made, communicate
through the flues A with flame chambers B, which in turn communicate
through downwardly inclined flues B with chambers C in which the ore to be
treated is placed, through openings C in the top of the chambers, provided
with covers C³.
In each flame chamber are partitions or baffles extending alternately in
opposite directions from opposite ends of the chamber so that the heating
medium flowing between them under the influence of the forced draught is
caused to pursue a circuitous course such as is indicated by the arrows in the
drawings passing across the ends of the flues B' so as to take each row of such
Hues (horizontal, in the construction illustrated) in succession to the row next
below it, so that every port in each row is afforded an equal opportunity of taking
its share of the passing current of hot gas.
In the construction of furnace illustrated in the accompanying drawings
there are four fire chambers A with their respective flame chambers B, and two
ore chambers C each of which communicates with the two flame chambers B
adjacent to it.
An exhaust, or vacuum chamber D, is provided between the two ore
chambers C; it leads at the top to an exhaust passage or flue E communicating
with a screening chamber F and an exhauster G. The ore chambers C com-
municate with the exhaust-chamber D by means of flues C which are inclined
upwardly from the ore-chambers. The flues B are controlled by valves B³
which preferably comprise a slab of refractory material sliding upon the
baffles 6. Other valves if desired of similar construction, may be used to con-
trol the flues C³. All these valves may be operated in any convenient way.
The floor D of the suction-chamber D is raised at the centre so as to form
two rather steep inclined planes leading down to outlets 12 closed by doors D³
at the ends of the chamber, the object of this being to collect any solid particles
which may be carried into the exhaust-chamber and deposited there.
The exhaust passage E has a number of hollow tube-like connections or
pockets E opening out of its lower side; they are each provided at the bottom
with a door 2, and have preferably funnel-shaped mouths where they communi-
cate with the passage E. A succession of rows of inclined baffle-plates E3 (shown
diagrammatically in Figure 2) are fixed in the exhaust passage E above the
pockets E; their function is to arrest any solid particles which may be carried
in the current of exhaust gases, and to deflect them into the pockets E. This
arrangement of a number of separate baffle-plates is of great advantage as the
stream of exhaust gases is broken up, and thus the solid particles are far more
likely to enter the pockets, than they would be if single large baffle-plates were
used, which by narrowing the passage would intensify the draught, and tend
to carry the particles over the mouths of the pockets.
In order to arrest any solid particles which may have escaped the pockets E¹
a screening chamber F is provided containing a series of fine screens F
Each of the ore chambers C is furnished with openings C in the bottom,
which are closed by suitable doors C opening into passages J running under
the ore chambers, and having rails J upon which trams or trucks can un for
removing the roasted ore.
Openings B3 are made in the outer walls of the flame chambers B, to afford
means of access to the flues B¹, they are closed by doors B. Similar openings C7
closed by doors Cs are made in the outer walls of the ore chamber C.
By means of the valve-controlled flues B and C³ the course of the heat may
be changed to various parts of the ore in the chamber C, so that no part of it
gets too hot. The heat is thus utilized to the greatest advantage, the distillation
of the volatile impurities takes place gradually, and consequently there is much
less risk of losing the valuable ingredients of the ore, than when the distilla-
tion takes place suddenly.

page_text: The operation of this improved roasting furnace is as follows:-
The material to be treated is placed in the chambers C through the open-
ing C¹, the covers C2 having been removed. The flues B and C³ are regulated
as may be desired by their respective valves. For example, it might be con-
venient to start with all the flues B and C open, in which case the whole mass
of material in the chamber C would be equally heated, then after a time, if
desired, by closing the lower flues, the heating medium may be directed only to
the upper portion of the material, while the portion at the bottom of the chamber
is allowed to cool before removal through the discharge openings C³. It is
obvious that by having these valve-controlled flues, and, as in the construction
illustrated, separate flame chambers, the application of the heating medium to
the whole mass of ore or other material is completely under control.
The gases from the ore chamber C are drawn through the flues C3 into the
suction or vacuum chamber D. Some solid particles of the material under, treat-
ment may be carried by the current of gas, and, of these some will fall to the
floor D of the suction chamber and gravitate down the inclined planes to the
outlet D².
The gases next pass through the exhaust passage E, and the stream is split
up as before described by the succession of rows of inclined baffle-plates E³;
solid particles carried by the gases, are intercepted by, say, the first row of
baffle-plates and diverted in a downward direction, some of them probably enter
the first pocket others pass on to the second row of plates where they are still
further diverted in a downward direction, and so on until all the baffle-plates
have been passed.
The gases, practically freed from solid particles, are finally drawn through
the screening chamber F where a series of sieves or equivalents arrests any
minute particles which may have escaped the baffle-plates.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is :-
1. A furnace for roasting ores and the like in which the heating medium is
passed through the material to be treated and is abstracted by means of flues
communicating with a suction chamber substantially as and for the purpose
described.
2. A furnace for roasting ore and the like in which the course of the heating
medium through the material to be treated can be changed by means of valve-
controlled flues communicating with the suction-chamber in the manner and for
the purpose described.
.
3. In an ore-roasting furnace an ore-chamber communicating with a flame-
chamber and an exhaust or vacuum chamber by means of valve-controlled
passages.
4. In an ore-roasting furnace of the kind described a flame-chamber such as B
in which partitions or baffles are arranged between the rows of flues or ports
substantially as and for the purpose specified.
5. In an ore-roasting furnace of the kind described the combination with a
suction-chamber such as D and flame-chamber such as B of an ore-chamber
such as C having valve-controlled, upwardly-inclined flues B¹ C³ in its side walls.
6. An ore-roasting furnace of the kind described comprising a central suction-
chamber placed between two ore chambers, each of which is heated by one or
more flame-chambers having separate fire-chambers substantially as described.
7. In an ore-roasting furnace an exhaust passage comprising a series of
pockets such as E¹ and a succession of rows of inclined baffle-plates such as E
for the purpose described.
8. In an ore-roasting furnace the combination with a suction-chamber such as D)
of an exhaust passage E baffle-plates E³ pockets E', screens F' and an exhauster G
substantially as described.

page_text: 9. In an ore-roasting furnace having an ore chamber, a flame-chamber, and a
suction or exhaust-chamber suitably connected one with the other, a passage-
way for trams or the like and discharge openings such as (5 substantially as
described.
ر
10. In an ore-roasting furnace of the kind described a suction-chamber such
as D having a bottom in the form of two inclined planes substantially as and
for the purpose described.
11. The complete ore-roasting furnace substantially as described and illustrated
in the accompanying drawings.
BOULT & WADE,
Agents for the Applicants.