IMPROVE- MENTS IN CRUCIBLE FURNACES AND IN APPARATUS APPERTAINING THERETO.
Year: 1883

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PROVISIONAL SPECIFICATION left by Benjamin Joseph Barnard Mills at
the Office of the Commissioners of Patents on the 21st July 1883. Communicate.l
to him from abroad by Georg Fischer, of Hainfeld in the Empire of Austria.
BENJAMIN, JOSEPH BARNARD MILLS of the firm of Harris and Mills of
23 Southampton Buildings in the County of Middlesex, Patent Agent IMPROVE-
MENTS IN CRUCIBLE FURNACES AND IN APPARATUS APPERTAINING THERETO. A
communication to me from abroad by Georg Fischer, of Hainfeld in the Empire of
Austria.
The improvements, to which the present invention relates, consist in a heating-
stove, forming a constituent part of the furnace and in which the charge that is to
be melted in the crucible furnace, is previously heated to such a degree, that the
bursting of the crucibles through the considerably higher temperature of the furnace
cannot occur.
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The previous heating of the charge takes place upon the lower part of the furnace
which is movable upon a rail-track and bears the fire-grate and the blast admitting
chamber; in order to regulate the admission of the blast and to enable the clearing
away of the fuel from the grate and the further utilization of the same, the said
bottom part of the furnace is provided with some special improved contrivances.
The improvements for regulating the admission of the blast consist in a plate
disposed beneath the fire-grate and turnable from outside; the clearing away of the
burning fuel from the grate is effected by a grate that can be removed from the
bottom part of the furnace, further by a jacket placed over the said grate and
which can be removed therefrom and finally by some special contrivances for
removing these said parts.
Said improvements relate further to a peculiarly shaped vessel, able to hold the
whole contents of a furnace-charge, to several small vessels named transfusing-
vessels and finally to the operations conditioned by the use of the said improved
furnace.
The heating-stove serves to obtain a rapid and regular working of the furnace.
Beneath this heating stove is placed the bottom part of the furnace into which the
charge has previously been introduced.
The heating stove consists of a cylinder lined with hollow cylinders of some

page_text: refractory material and provided with a cap equanу mmed with some refractory
substance.
In order to draw off the smoke and the gases produced by the combustion of the
fuel the cap of the heating stove is provided with a chimney flue having an outer
opening and a regulating damper.
The cylinder is enclosed in a jacket, which serves as a guide to the cylinder
whilst the cylinder is lowered upon the bottom part of the furnace.
In order to facilitate the easy lowering of the cylinder together with the chimney-
flue, it is suspended upon chains running over pulleys and bearing at their opposite
end counterweights; by means of these chains and counterweights the cylinder is
so balanced, that its raising and lowering can be effected very easily, without
needing any considerable exertion of power.
As soon as the fuel is placed upon the grate and ignited the cylinder is let down
and the charge heated to incandescence. The blast is introduced by pipes.
When the charge has been sufficiently heated, the cylinder is raised again and the
bottom part of the furnace is conveyed directly to the melting furnace. The
previous heating of each charge requires about three times as much time as the
melting process, the continuous working of each melting furnace requires a continuous
working of three heating stoves.
In such an arrangement a melting furnace is placed upon a turn-table and com-
municates by means of rail-tracks with three heating stoves; other rail-tracks lead
from the turn-table to the places where the charge is introduced and where the
melted metal is discharged.
In order to regulate the admission of the blast and consequently the heat
developed in the furnace, a perforated plate is disposed beneath the fire-grate, the
perforated apertures of which plate correspond with the openings of the grate.
This perforated plate is fastened to the turn-table supporting arms fitted upon a
spindle which can be turned by means of a lever. By thus turning the plate the
openings of the grate can be shut more or less, according to whether it is wanted
to let in more air through the tuyeres and through the central blast-pipe than
through the apertures.
In order to enable a rapid clearing and cooling of the bottom part of the furnace,
the jacket, its lining and the fire-grate are so constructed that they can be removed
from the bottom part by any desired means. The removal of the jacket is effected
by means of a yoke, bow or hoop and the removal of the fire-grate is effected by
means of a horizontal beam, connected with two vertical bars in the bottom ends of
which are two trunnions. These trunnions are rivetted in the fire-grate and are
capable of turning in the bottom ends of the bars so as to facilitate the tilting of
the grate and the clearing off of the burning fuel and of the ashes.
The burning fuel taken from the furnace when the melting process has been
terminated may be employed for feeding annealing furnaces with a continuous
working or for some other similar purposes.
The melted metal is emptied from the furnace into a large vessel, the size of
which is so considerable, that it can hold the contents of a whole charge.
This vessel consists of a reservoir made of thick metal plates and provided with
a lining of some refractory material; on both sides of the vessel in places corre-
sponding to its centre of gravity, it is provided with two trunnions, by means of
which it is suspended from a crane.
The top of the vessel is provided in front with a spout and behind with an
incision serving for the removal of the slag. In order to prevent the outward
radiation of the heat, said vessel is enclosed in an isolating jacket, the space
between the reservoir and the jacket being filled with refractory sand or with some
other heat-resisting material. The vessel can be covered by a lid fitting in the
inwardly bent projecting flange fastened to the top rim of the vessel; the lid is
provided with an aperture for introducing the blast pipe.
In order to convey the said vessel to the crane-hoist, the vessel is placed in a
box filled with refractory sand or some other isolating material, so as to prevent

page_text: the outward radiation of heat, and this box is placed upon a truck or car. For
manufacturing small castings or figured ingots or soft cored steel goods the
melted metal is transfused from this vessel into transfusing vessels of a smaller
size. These portable transfusing vessels are provided each with two spouts and
with a groove for the tongs. A lid is employed to cover the said transfusing vessels
and is provided with a hopper.
It is evident that these transfusing vessels may also be previously heated; they
can be filled either from the large vessel or directly from the crucibles.