IMPROVEMENTS IN FURNACES FOR MELTING METALS AND METALLIC ALLOYS, AND FOR OTHER METALLURGICAL OPERATIONS, AND FOR HEATING AND ANNEALING METALS AND METALLIC ALLOYS
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by Charles Carr at the Office of tho
Commissioners of Patents on the 11th January 1879.
CHARLES CARR, the younger, of Smethwick, in the County of Stafford, Brass-
founder. "IMPROVEMENTS IN FURNACES FOR MELTING METALS AND METALLIC
ALLOYS, AND FOR OTHER METALLURGICAL OPERATIONS, AND FOR HEATING AND
ANNEALING METALS AND METALLIC ALLOYS."
My Invention consists of the improvements hereinafter described in furnaces,
which improvements are especially applicable to furnaces for melting metals and
metallic alloys, such, for example, as copper, brass, and iron, but which improve-
ments may also be applied to furnaces for other metallurgical operations, such, for
example, as the refining of copper and brass, as well as to furnaces for heating and
annealing metals and metallic alloys.
I will describe my improvements in connection with a furnace such as is commonly
used for inelting copper and brass.
I make the outer casing of the furnace of plates of iron, rivetted or bolted
together. The lower part of the said iron casing constitutes the ash pit of the
furnace, and the combustion chamber of the furnace is contained in the upper part
of the said casing. The combustion chamber is made of fire brick, and is either
circular or rectangular in plan internally, its exterior being by preference
rectangular.
The combustion chamber does not fill the part of the casing in which it is situated,
there being a space all round the said combustion chamber and between it and the
casing, which space in the upper part of the furnace is filled with sand or other bad
conductor of heat. The upper part of the combustion chamber is fixed, being built
upon iron shelves passing round the interior of the casing, the said shelves being
made of cast iron and belted to the casing. The lower part of the combustion
chamber is built upon shelves running round the inside of the casing, the front and
back shelves being fixed, and the side shelves being loose and resting upon the fixed
front and back shelves.
The fire bars are supported on bearers carried by brackets at front and back of
the ash pit.
The fire bars may be drawn out in the ordinary way, or when necessary may bo
let fall altogether by unbolting the front brackets carrying their bearers.
The lower part of the combustion chamber which requires more frequent renewing
than the upper part can be removed and rebuilt without disturbing the upper part
by removing the iron shelves on which it is supported. The space between the

page_text: outside of the lower part of the combustion chamber is not filled with sand or other
bad conductor of heat as the like space in the upper part of the furnace is, but is
left open and constitutes a channel all round the lower part of the combustion
chamber for supplying air to the furnace. By inserting small distance pieces
between the bricks of the lowest two or three courses instead of fire clay, spaces
between the said courses are left through which air enters the sides of the com-
bustion chamber at the lower part, and together with air entering between the fire
bars effects a vigorous combustion of the fuel in the furnace. Sliding dampers
working in the sides of the lower part of the combustion chamber are employed to
determine the amount of air entering the furnace, and thereby to regulate the com-
bustion in and heat of the furnace. The fuel and melting pot are introduced at the
top of the furnace, and the heated air and products of combustion pass by an
opening at the top and back of the furnace into a chimney stack.