IMPROVEMENTS IN CUPOLA FURNACES FOR SMELTING PIO METAL AND WROUGHT IRON
Year: 1880

page_text: LETTERS PATENT to Gerard Wenzeslaus von Nawrocki, of the Firm of
J. Brandt and G. W. von Nawrocki, Civil Engineers and Patent Solicitors, of
No. 124, Leipziger Strasse, Berlin, in the German Empire, for an Invention
of "IMPROVEMENTS IN CUPOLA FURNACES FOR SMELTING PIO METAL AND
WROUGHT IRON." A communication by Gustav Ibrugger, of Norden,
Ostfriesland, in the German Empire.
PROVISIONAL SPECIFICATION left by the said Gerard Wenzeslaus von
Nawrocki at the Office of the Commissioners of Patents on the 20th March
1880.
GERARD WENZESLAUS VON NAWROCKI, of the Firm of J. Brandt and G. W. von
Nawrocki, Civil Engineers and Patent Solicitors, of No. 124, Leipziger Strassc,
Berlin, in the German Empire. "IMPROVEMENTS IN CUPOLA FURNACES FOR
SMELTING PIG METAL AND WROUGHT IRON." [A communication by Gustav
Ibrugger, of Norden, Ostfriesland, in the German Empire.]
These improvements relate to a construction of cupola furnace for smelting pig
metal and wrought iron, for which Letters Patent were granted to me as a
communication from G. Ibrugger, dated 12th September 1879, No. 3654. The said
cupola furnaco was provided with a separate melting chamber below the cupola
chamber, which was heated by the passage of the heated combustible gases into it
from the cupola chamber through an opening in the bottom of the latter, which
gases were burnt by the admission of air blast into the said melting chambor, the
object being to produce intense heat for the melting of wrought iron in such lower
chamber, into which the melted cast iron from the cupola chamber was then caused
to run so as to become mixed therewith.
According to one of the present improvements the heat produced in the said
lower chamber is further utilised by conducting the flames and hot gases thence
into one or more other chambers, cither at the side thereof or communicating
therewith, in which metal can be melted either on the open hearth. or in crucibles,
or which may serve as drying stoves or annealing ovens, or the said hot gases may
be conducted into hot blast stoves for heating the air blast, or into the flues of a
steam boiler. In some cases it will be advantageous to introduce a suitable

page_text: quantity of heated air into the said gases, so as either to effect their more perfect
combustion, or to act as a vehicle for conveying the heat thereof.
According to another improvement, instead of forming a single aperture contrally
in the cupola chamber bottom, through which the gases and melted pig metal both
pass into the melting chamber below, two or more such apertures are provided, one
or more of which may serve separately for conveying the gases into the lower
chamber, while the other or others may serve for the passage of the liquid pig
metal; these passages are by preference formed at the side or sides of the cupola
chamber, and by preference the bottom is made to slope down towards a recess in
the side in which the said openings are situated. By this means the combustible
gases are afforded a freer passage into the melting chamber, so that the cupola
chamber forms as it wore a gas generator for the former, comparatively little of
such gases escaping through the upper open end of the cupola chamber, which need
in that case, not be provided with a chimney, and can be filled to a greater extent
with fuel, the requisite downward draught being provided by a chimney into which
the products of combustion pass, after doing duty in the melting chamber and
other chambers above referred to. The said melting chamber need not necessarily
be arranged immediately beneath the cupola chamber, as described in the Specifi-
cation above referred to, as it may also be placed at the side-thereof, but at a lower
level.
Another improvement relates to the construction of the melting chamber and the
mode of introducing the wrought iron to be melted. Instead of placing a charge of
wrought iron on the bed of such chamber to be melted down, there is provided at
the charging hole a raised bench or slab of firebrick inclining towards the bed, and
upon this bench the wrought iron is laid, so that as it melts it runs down on to the
bed and mixes with the liquid cast iron descending from the cupola chamber. By
this means the melting and mixing process can be carried on continuously by
feeding additional wrought iron on to the said bench as it melts away.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Gorard Wenzeslaus von Nawrocki in the Great Seal Patent Office on
the 18th September 1880.
GERARD WENZESLAUS VON NAWROCKI, of the Firm of J. Brandt and G. W. von
Nawrocki, Civil Engineers and Patent Solicitors of No. 124, Leipzigerstrasse,
Berlin, in the German Empire. "IMPROVEMENTS IN CUPOLA FURNACES FOR
SMELTING PIG METAL AND WROUGHT IRON." A communication by Gustav
Ibrugger, of Norden, Ostfriesland, in the German Empire.
These improvements relate to a construction of cupola furnace for smelting pig
metal and wrought iron, for which Lettors Patent were granted to me as a
communication from G. Ibrugger, dated 12 September 1879, No. 3654. The said
cupola furnaco was provided with a separate melting chamber below the cupola
chamber, which was heated by the passage of the heated combustible gases into it
from the cupola chamber through an opening in the bottom of the latter, which
gases were burnt by the admission of air blast into the said melting chamber, the
object being to produce intense heat for the melting of wrought iron in such lower
chamber, into which the melted cast iron from the cupola chamber was then caused
to run so as to become mixed therewith.
According to one of the present improvements the heat produced in the said
lower chamber is further utilised by conducting the flames, and hot gases thence
into one or more other chambers, either at the side thereof, or communicating
therewith, in which metal can be melted either on the open hearth or in crucibles,
or which may serve as drying stoves or annealing ovens, or the said hot gases may
be conducted into hot blast stoves for heating the air blast, or into the flues of a
steam boiler. In some cases it will be advantageous to introduce a suitable
quantity of heated air into the said gases, so as either to effect their more perfect
combustion, or to act as a vehicle for conveying the heat thereof.
According to another improvement, instead of forming a single aperture centrally
in the cupola chamber bottom, through which the gases and melted pig metal both
pass into the melting chamber below, two or more such apertures are provided, one
or more of which may serve separately for conveying the gas into the lower
chamber, while the other or others may serve for the passage of the liquid pig
metal; these passages are by preference formed at the side or sides of the cupola
chamber, and by preference, the bottom is made to slope down towards a recess in the
side in which the said openings are situated. By this means the combustible gases
are afforded a freer passage into tho melting chamber, so that the cupola chamber
forms as it were a gas generator for the former, comparatively little of such gases
escaping through the upper open end of the cupola chainber, which need in that
case not be provided with a chimney, and can be filled to a greater extent with
fuel, the requisite downward draught being provided by a chimney into which the
products of combustion pass after doing duty in the melting chamber and other
chambers above referred to. The said melting chamber need not necessarily be
arranged immediately beneath the cupola chamber, as described in the Specification
above referred to, as it may also be placed at the side thereof, but at a lower level.
Another improvement relates to the construction of the melting chamber, and the
mode of introducing the wrought iron to be melted. Instead of placing a charge of
wrought iron on the bed of such chamber to be melted down, there is provided at
the charging holo a raised bench or slab of fire brick inclining towards the bed,
and upon this bench the wrought iron is laid, so that as it molts it runs down on
to the bed, and mixes with the liquid cast iron descending from the cupola
chamber. By this means the melting and mixing process can be carried on
continuously by feeding additional wrought iron on to the said bench as it melts
away.

page_text: DESCRIPTION OF THE DRAWINGS.
Fig. 1 of the accompanying Drawings shews a vertical section of the above
described improved construction of cupola furnace, and Fig. 2 shews a section at
right angles to that shewn at Fig. 1. A is the lower chamber into which the
melted pig metal together with the hot gases pass from the upper chamber through
openings and d, the floor B of the upper chamber being inclined towards the
opening is situated in a recess a at the side of the furnace. There may if desired
be more than two such openings band d. The air required for the combustion of
the gases in the chamber A is introduced from the air chamber surrounding the
upper part of the cupola through the pipe and passage g.
The flames and gaseous products of combustion pass from the chamber A through
the opening into another chamber D at the side of the furnace, in which the heat
is further utilised for any other purpose, such as for melting metal on the open
hearth, or in pots E; or the said hot gases may be employed for heating steam
boilers, hot air stoves, drying rooms, annealing furnaces for malleable cast iron, and
the like. It will in many cases be advantageous to provide a supply of suitably
hented air, which is either employed for assisting the combustion, or as a vehicle
for conveying the heat.
In the chamber A is provided a bridge on which the wrought iron is placed, so
as to be heated up to melting point before mixing with the cast iron bath, and
thus to prevent any injurious reduction of the temperature and fluidity of the metal
by its admixture. It will be seen that by this arrangement the admixture of the
wrought iron may take place continuously by placing from time to time fresh
charges of wrought iron on the bridgo l.
Having thus described the nature of the said Invention, and in what manner
the same is to be performed, as communicated to me by. my correspondent,
I. claim,―
First. The combination with a cupola furnace of a lower chamber A communi-
cating thorewith by one or more openings, and having a charging door for the
introduction of wrought iron, a tapping hole, an opening for drawing off the
gaseous products of combustion to be utilised for other heating operations, and
a passage for the introduction of air blast, as herein described.
Second. The use, in combination with the chamber A referred to in the preceding
claim, of the bridge l for receiving the wrought iron to be added to the pig metal.
In witness whereof, I, the said Gerard Wenzeslaus von Nawrocki, have
hereunto set my hand and scal, this Fourteenth day of September, in the
year of our Lord One thousand eight hundred and eighty.
CEDARD WENZES AUS VON VIIKHOGET