AN IMPROVED FURNACE FOR FUSING OR MELTING METALS AND THEIR ALLOYS
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by George Lamb Scott at the Office of
the Commissioners of Patents on the 8th October 1878.
George Lamb SCOTT, of Manchester, in the County of Lancaster, Engineer. “AN
IMPROVED FURNACE FOR FUSING OR MELTING METALS AND THEIR ALLOYS."
My said Invention relates to a special arrangement of furnace or heat generating
chamber in connection with one or more separate chambers in which the metal or
metallic alloy to be fused or melted is deposited, and therein subjected to the
action of the heat or flame derived from the combustion of the fuel contained in
the heat generator under the influence of a strong blast of air propelled by a
revolving fan or other blowing machine.
One modification of my Invention consists of an outer metallic casing surrounding
a chamber or generator, rectangular or otherwise in section, lined with fire-brick or
other heat-resisting material, and of sufficient capacity to contain the necessary
amount of fuel to generate the requisite heat. This chamber possesses an opening
to admit fuel, closed by a metal lid covered by fire-clay block or shield, and also at
bottom or lower end is provided with similarly shielded hinged door held up by
cotter or wedge, for the purpose of avoiding ashes or scorice or other incombustable
residuum.
The shield or block covering bottom door may be so constructed as to provide a
series of hollows or cavities for the purpose of receiving and forming into ingots
any fluid metal, which through breakage or otherwise may escape from the crucibles
or melting pots placed in the melting chamber or chambers. On each side of the
heat generator is a pipe to convey the blast which discharges into a cavity or air
chamber, communicating by a series of small tuyere openings of suitable calibre
formed in the fire-clay or other refractory lining surrounding the interior, and so
spaced at different levels as to ensure as far as possible thorough and complete
combustion of the fuel without excess of air beyond that chemically requisite to
furnish the necessary saturating equivalent of oxygen. The flame and gaseous
matters resulting from such combustion are conducted into the melting chamber or
chambers, through a series of openings provided for such purpose near the bottom
of generator, which debouche into inclined channels extending right across bottom
Daina 71

page_text: of melting chamber or chambers. Each melting chamber is included in an
extension of the same metal casing, is lined with heat-resisting refractory material,
and is made oblong in section with rounded ends, or of any other suitable form or
shape, according to the desired capacity of each particular furnace, the material it is
intended to fuse, the number and size of crucibles or otherwise it is required to
contain. By means of the channels traversing its bottom or lower part the hot
gaseous products of combustion are uniformly distributed over the whole area and
thus brought into uniform and immediate contact with the metal itself or the
.crucibles which contain it, and afterwards escape through an orifice or orifices
capable of being contracted or closed by means of a damper or dampers. Each
chamber is also provided with one or more hinged lids, each protected by fire-clay
slab for convenience of charging materials introducing or removing crucibles.
Another modification of my Invention consists in the introduction of a gas or
combustion chamber into which the gaseous matters, such as carbonic oxide,
carburetted hydrogen, or other inflammable gases evolved from the imperfect or
partial combustion of the fuel in the generator are made to discharge; the quantity
of air admitted through the tuycres in generator being so regulated as to suffice to
merely convert the combustible constituents of the fuel into the above-named
gaseous matters. Into this combustion chamber a sufficiency of blast, either hot, as
by preference, or cold, is introduced to effect the perfect saturation with oxygen of
the gaseous fuel evolved by the generator. It is also proposed in some cases to
inject and mingle with the gaseous fuel in the above chamber or the solid fuel in
the generator, various hydrocarbons, either by the agency of the blast or otherwise
in order when required to thereby increase the intensity or quality of heat and
flame.
The fusing or melting may be eithor arranged as described in previous modifi-
cation or may take any other suitable form as found most convenient in dealing
with various metals or metallic alloys.
The heating of the whole or part of the blast may be effected by means of the
waste heat of the resultant gaseous matters of combustion by passing them amongst
and around pipes or channels of metal or other suitable material enclosed in a
chamber or flue before such products of combustion are permitted to escape into
the chimney. The direction of motion of the air blast being made as far as possible
contrary to that of the escaping hot gases.