A FURNACE FOR REDUCING ZINC AND OTHER METALS
Year: 1884

page_text: I, GERARD WENZESLAUS VON NAWROCKI, of 124 Leipzigerstrasse, Berlin; in the
Kingdom of Prussia, Germany, do hereby declare the nature of said Invention for
A FURNACE FOR REDUCING ZINC AND OTHER METALS, to be as follows:-
This Invention has for its principaliobject to convert the carbonic acid, produced
by the reduction of metals from their ores, into carbonic oxide, which may after-
wards be used as fuel, and thereby to utilise a portion of the heat generated by the
consumption of coal in reducing furnaces.
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For this purpose two vertical furnaces are placed symmetrically to each other and:
connected near the top by a horizontal flue or canal.
Each furnace is enclosed by a gas tight-iron casing and surrounded at its hottest,
part with a water cooling ring. The base of the furnace is widened so as to form an
annular space for the escape of the gases and for the admission of air.
The oblique sole communicates with a small hearth situated outside the casing
and serving to facilitate the removal of the molten metal. The base of the furnace
has also lateral doors for removing the ashes and clinkers.
Each furnace is provided at the top with a closed funnel and a conical valve for
the continuous feeding of coal, ores and flux, also with openings for pushing down
the charges.
A mushroom-valve and valve seat connected with the base of each furnace serves
for the alternate admission of air to the furnaces and the discharge of gas from
the same.
The valve seat is also connected by a pipe with a condenser provided with
heating apparatus and leading to a cooler. The carbonic oxide with or without
water gas escapes through a pipe from the top of the cooler.
The process of operation is as follows: The two furnaces are filled with coal,
a fire is made at the bottom and the resulting gases are conducted from the top
of the cooler to an exhaustor. The suction thus produced causes atmospheric air
to pass through the open slot of the valve seat, to the coal, while through the other
slot, which is covered by the mushroom valve, gases are sucked out of the other
furnace. A blowing engine may also be used in which case the upper part of the
valve seat is surrounded by an air tight casing connected with the blower; steam
may be introduced simultaneously with the air supply, so as to produce hydrogen

page_text: in addition to the carbonic oxide. The slide valve is kept cool by water or molten
metal. As soon as the coal in the first furnace has become red hot, the slide valve is
reversed, and thereby the circulation of gases changed. When the coal in the
second furnace has also commenced to glow, the attendant may begin to charge
ores, mixed with coal, through the funnel at the top of the furnace.
The reduced metals, which remain in a molten state, collect in the external
⚫ hearth.
The vaporised metals and metallic oxides pass over to the second furnace to be
completely reduced, while at the same time any carbonic acid which may still be
present is converted into carbonic oxide.
The metallic vapours are drawn off and condensed in the condenser mentioned
above.
If these furnaces are to be used for the direct reduction of zinc blende with coal,
whereby carbon is combined with sulphur, an efficient condenser filled with water
is to be inserted between the gas outlet of the cooler and the exhaustor.
For treating ores which can only be reduced with difficulty, or ores with much
slag, or if inferior coals only are available, it is necessary to produce higher
temperatures than those obtainable by the combustion of coal to carbonic oxide.
These high temperatures may be produced by previously heating the air admitted
for combustion, by means of any suitable calorifier, heated by a portion of the
gases produced in the furnaces.
Or a portion of the gases produced in the furnaces may be burnt in a closed
chamber built into the interior of the reducing furnace, so that the refractory walls
of the said chamber, and consequently also the surrounding space of the reducing
furnace, is maintained at a white heat.
The internal heating apparatus.may have various shapes, but preferably that of
a hollow cone surrounded by a conical jacket, both cones being surmounted by short
cylinders. The heating gas would in this case be admitted through an annular
space outside the base of the inner cone and ascend up between the two cones,
while atmospheric air is admitted through an annular space inside the base of the
outer cone and ascends between the two cones, being first kept separate from the
combustible gas by a short partition. The combustible gas is mixed with the air
and burnt in the upper part of the annular space left between the inner and outer
cone, and the products of combustion descend through the inner cone in order to
escape through a lateral flue at the base of the cone.
Dated this 15th day of March 1884.
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page_text: I, GERARD WENZESLAUS VON NAWROCKI, of the firm of J. Brandt and G. W.
von Nawrocki, Patent Solicitors and Civil Engineers, of 124 Leipzigerstrasse,
Berlin, Prussia, Germany, do hereby declare the nature of said Invention for
A. FURNACE FOR REDUCING ZINC AND OTHER METALS, and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement:--
The principle on which this Invention is based consists in converting into
carbonic oxide the carbonic acid, produced by combustion and by the reduction of
metals from their ores, so that the apparatus forms, as it were, a generator of
carbonic oxide in which the units of heat, generated by the combustion of coal and
which would otherwise be lost may be utilized for the production of carbonic oxide
which can afterwards be used as a fuel
In .describing the Invention reference will be made to the accompanying
Drawing, of which Fig. 1, is a longitudinal section, Fig. 2, a horizontal section
and Fig. 4a sido elevation of a generator; Fig. 3, a section through the valve;
and Fig. 5 is a vertical section of a modified generator..
"Two vertical furnaces H, are connected by a horizontal flue or canal X, and
arranged symmetrically to each other; the furnaces are enclosed by a gas tight iron
casing A and surrounded at the hottest part with a water cooling ring B.
The base of the furnace, I, is widened so as to form an annular space W for the
escape of the gases and the admission of air, when the charge falls to the bottom.
The oblique sole of the furnace communicates with a small hearth K; C and D
are iron doors with Morton's fastening which serve to remove the ashes and slags.
The hoppers E and the conical valves F serve for the continuous feeding of coal,
ores and flux.
The openings Z serve for pushing down the charge.
air to the furnaces
The valve is also
The mushroom valve G Gi effects the alternate admission of
and the discharge of gas 'from the same through the pipes L.
connected with a pipe M dipping into the condenser N, adapted to be heated at V
and combined with a cooler O.
The pipe P is the outlet for the carbonic oxide which is sometimes mixed with
water gas.
The process of operation is as follows: The two furnaces H are filled with
charcoal, a fire is made at W, and the resulting gases are drawn off at P by an
exhaustor. The suction thus produced causes atmospheric air to pass through the
open slot of the valve seat to the fuel, while through the other slot, which is covered
by the mushroom valve, gases are sucked out of the other furnace.
A blowing engine may also be used, in which case the upper part of the valve is
surrounded with an air tight casing, into which ends the delivery pipe of the
blower; steam may also be introduced simultaneously with the air supply, so as to
produce hydrogen in addition to carbonic oxide. The mushroom valve G G¹ is
kept cool by water or molten metal.
As soon as the charcoal in the first furnace has become red hot, the valve is
reversed and thereby the circulation of gases changed. When the coal in the
second furnace has also become incandescent, the charging of ores mixed with
charcoal, through the hopper at the top of the furnace E F may commence.
The reduced metals remaining in a molten state, collect in the external hearth K.
The vaporized metals and metallic oxides pass over to the second furnace to be
completely reduced, while at the same time any carbonic acid which may still be
present is converted into carbonic oxide.

page_text: The metallic vapours are drawn off and condensed in the condenser N. The
carbonic oxide, and eventually the water gas, passes through P into a gas holder,
to be subsequently used as fuel. If these furnaces are to be used for the direct
reduction of zinc blende with charcoal, whereby carbon is combined with sulphur,
an efficient condenser filled with water is to be inserted between. the gas outlet P
of the cooler, and the exhaustor.
For treating ores which can only be reduced with difficulty, or ores with much
slag, or if inferior charcoal only is available, it is necessary to produce higher
temperatures than those, obtainable, by the combustion of charcoal to carbonic
oxide.
These high temperatures may be produced:
any
a. By previously heating the air adinitted for combustion, by means of
well known calorifier heated by burning in the latter a portion of the gases
produced in the furnaces.
I
b. A portion of the gases produced. may be burnt in a closed chamber built into
the interior of the reducing furnace, whereby the refractory walls of the said
chamber, and consequently also the surrounding space of the reducing furnace, are
maintained at a white heat.
This internal heating apparatus may have various shapes, for instance such as
represented in Fig. 5 of the accompanying Drawing.
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The heating gas is supplied through ring Q, passes into the space R under the
bearth of the furnace, and consumes the gas in the combustion chamber S; the gases
of combustion escape through T and U into the flue V leading either directly to
the chimney or into a Siemens regenerative apparatus in order to heat the gas and
air supplied to the furnace.
1
Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed, I declare that what
claim is:
1. The arrangement of two combined vertical furnaces, substantially as
described.
2. The internal heating apparatus for obtaining a high temperature.