IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR MANUFACTURING METALLIC ALLOYS MORE PARTICULARLY THOSE OF ZINC
Year: 1883

page_text: LETTERS PATENT to Gustav. Selve of Altena in the county of Westfalen and
State of Prussia, German Empire for an Invention of "IMPROVEMENTS IN
THE METHOD OF AND APPARATUS FOR MANUFACTURING METALLIC ALLOYS
MORE PARTICULARLY THOSE OF ZINC "
PROVISIONAL SPECIFICATION left by the said Gustav Selve at the Office
of the Commissioners of Patents on the 16th June 1883.
GUSTAV SELVE of Altena in the County of Westfalen and State of Prussia,
German Empire "IMPROVEMENTS IN THE METHOD OF AND APPARATUS
MANUFACTURING METALLIC ALLOYS, MORE PARTICULARLY THOSE OF ZINC"
FOR
The present invention has more particularly for its object, first, to effect the
smelting of the superior metals, in particular copper and zinc, to form alloys, such
as brass and ton bac, in regenerative gas furnaces in such a manner that, notwith-
standing the high temperatures required for smelting the more refractory metals,
and at which the zinc volatilises, there shall be only slight losses of this metal.
Second, to prevent the various disadvantages attendant on the working of furnaces
where the smelting is effected in crucibles with direct application of fire heat,
which consist, in addition to the loss of zinc, in the continued exposure of tho
workmen to a high degree of heat, and to the injurious fumes of zinc. For theso
purposes, the smelting is effected in crucibles in which, in consequence of the modo
in which they are constructed and the manner in which they are set in the regene-
rative furnace, there exists at bottom a much higher temperature than at top. In
order to obtain this difference of temperature, the crucibles are made somewhat
longer and of smaller diameter than usual, and only the lower part thereof is
situated inside the furnace, the upper part being made to project through the arch
or roof of the furnace. For smelting, for example, copper and zinc in such crucibles,
to form brass, the copper is first placed in the crucible and is melted at a
temperature of from 1922° to 2192° Fahr., and the zinc is then quickly added in

page_text: the requisite proportions, such as from one third to one half the quantity of copper,
and so much of brass waste is added to render the whole pasty, while, at the same
time, cooler layers of metal are by this means formed in the upper part of the
crucible. As, in addition to this, the upper part of the crucible is outside the
furnace, the upper layers of metal are of a much lower temperature than below,
and they are maintained at this low temperature by the successive further addition
of cold brass waste, thereby causing the condensation of the greater part of the
zine vapors as they rise up into the cooled layers from the lower highly heated
layers of metal. By this means only small losses of zinc can take place, and
these mainly at the first introduction of the zinc into the molten copper; On the
_average_only_about 1 to + the loss of zinc which takes place in the ordinary
smelting process of zinc is experienced by this method. After the-whole-of-the-
metal is melted, the crucible is removed, and the contents stirred, so as to obtain
a.homogeneous alloy. Should, during the stirring, further zinc vapors be formed,
the upper liquid layers of metal, which are still at a lower temperature than the
lower ones (about 1652° Fahr. at top and 2192° Fabr. below), are cooled with
water, thus causing the condensation of such vapors.
The advantages of this method of smelting and mode of setting the crucibles are
mainly as follows:-
1. The loss of zinc is reduced to a minimum, as it is almost entirely taken up by
the alloy.
2. A high degree of efficiency and regularity of working is obtained.
3. A considerable saving of fuel is effected, as the furnace is closed during the
smelting process with the exception of the small interstices between the crucibles
and the openings, the latter being closed quickly and easily by covers when the
crucibles are removed.
4. The labor is easier and less injurious, as the workman is hardly at all
subjected to the zinc fumes, and the heat is much less felt.
5. The castings remain clean because the alloy cannot be deteriorated during
the smelting by particles of fuel such as frequently fall into the crucibles with
ordinary furnaces.
6. There is a less expenditure of crucibles, as these sustain double the number
of charges as compared with the ordinary process of smelting.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Gustav Selve in the Great Seal Patent Office on the 23rd October
1883.
* Gustav Selve of Altena in the county of Westfalen, and state of Prussia,
German Empire "IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR
MANUFACTURING METALLIC ALLOYS, MORE PARTICULARLY THOSE OF ZINC"
The present invention has more particularly for its object, first to effect the
smelting of the superior metals, in particular copper and zinc, to form alloys such
as brass and tombac in regenerative gas furnaces, in such a manner that, notwith-
standing the high temperatures required for smelting the more refractory metals,
and at which the zinc volatilises, there shall be only slight losses of this metal.
Second, to prevent the various diadvantages attendant on the working of furnaces
where the smelting is effected in crucibles with direct application of fire heat,
which consist, in addition to the loss of zinc, in the continued exposure of the
workmen to a high degree of heat and to the injurious fumes of zinc.
For these purposes, the smelting is effected in crucibles, in which, in consequence
of the mode in which they are constructed and the manner in which they are set
in the regenerative furnace, there exists at bottom a much higher temperature that
at top. In order to obtain this difference of temperature, the crucibles are made
somewhat longer and of somewhat smaller diameter than usual, and only the lower
part thereof is situated inside the furnace, the upper part being made to project
through the arch or roof of the furnace. For smelting, for instance, copper and
zinc in such crucibles, to form brass, the copper is first placed in the crucible and is
melted at a temperature of from 1922° to 2192° Fahr:, and the zinc is then quickly
added in the requisite proportions, such as from one third to one half the quantity of
copper, and so much of brass waste is added to render the whole pasty, while, at the
same time, cooler layers of metal are by this means formed in the upper part of the
crucible. As, in addition to this, the upper part of the crucible is outside the furnace,
the upper layers of metal are of a much lower than below, and they are maintained at
this low temperature by the successive further addition of cold brass waste, thereby
causing the condensation of the greater part of the zinc vapors as they rise up into
the cooled layers from the lower highly heated layers of metal. By this means,
only small losses of zinc can take place, and these mainly at the first introduction
of the zinc into the molten copper; on the average, only about from one third to
one fourth the loss of zinc which takes place in the ordinary smelting process, is
experienced by this method.
After the whole of the metal is melted, the crucible is removed and the contents
stirred, so as to obtain a homogeneous alloy. Should, during the stirring, further
zinc vapors be formed, the upper liquid layers of metal, which are still at a lower
temperature than the lower ones (about 1652° Fahr at top and 2192° Fahr below)
are cooled with water, thus causing the condensation of such vapors.
The accompanying drawing shews in longitudinal and transverse section and
plan the construction of a furnace A arranged according to this invention, with
five crucibles T. The long crucibles, somewhat smaller in diameter than usual, are
introduced through openings in the roof of the furnace, on to refractory blocks f, so
as to project with their upper ends out of the furnace.
The roof of the furnace is formed of refractory slabs p having openings corre-
sponding to the diameter of the crucible. Between the sides of the crucible and
the opening a small space is left (about 0.2 ins) in order to prevent the two from
melting together. The bed of the furnace inclines slightly from all sides to the

page_text: middle, so that should a crucible break during the smelting, the metal can at once
be removed through the tapping bole S. The furnace may be constructed to take
a greater or less number than five crucibles, according to requirements, and theso
may be arranged in two or more rows, as shewn at fig. 4. The advantages of this
method of smelting and node of setting the crucibles are mainly as follow:-
'1, The loss of zinc is reduced to a minimum, as it is almost entirely taken up-by
the alloy.
2, A high degree of efficiency and regularity of working is obtained.
3, A considerable saving of fuel is effected, as the furnace is closed during the
smelting process with the exception of the small interstices between the crucibles
and the openings the latter being closed quickly and easily by covers when the
crucibles are removed.
4. The labor is easier and loss injurious as the workman-is-hardly-at-all-subjected-
to the zinc fumes, and the heat is much less felt.
-
5. The castings remain clean because the alloy cannot be deteriorated during the
smelting by particles of fuel, such as frequently fall into the crucibles with ordinary
furnaces.
6. There is a less expenditure of crucibles, as these sustain double the number of
charges, as compared with the ordinary process of smelting.
Having thus described the nature of this invention and in what manner the
same is to be performed, I claim :-
First: The method of smelting alloys, more particularly those of zinc, in closed
crucibles that are situated with their lower parts in the furnace, while the upper
parts project out of the same, whereby the zine vapors generated in the lower
hotter layers of metal become condensed in rising up into the cooler upper layers.
Second: In smelting zinc alloys, the method of effecting the condensation of the
zinc vapors generated in the lower part of the crucible by means of the coolor
upper layers of metal therein.
-Third: The construction of furnaces for smelting metallic alloys, wherein the
crucibles are only partly contained in the furnace chamber, the upper part thereof
being made to project out of the furnaco.
In Witness whereof I the said Gustav Selvo have hereunto set my hand and
seal this twenty first day of October in the year of our Lord one thousand eight
hundred and eighty-three.
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