Improvements in Crucible Melting Furnaces.
Year: 1896

page_text: Date of Application, 24th-Dec., 1896
Complete Specification. Left, 24th Sept.,.1897-Accepted, 30th Oct., 1897
PROVISIONAL SPECIFICATION.
Improvements in Crucible Melting Furnaces.
I, WILLIAM KIRKHAM,, of 22, Brinsworth Street, Attercliffe, Sheffield, in the County
of York, Furnace Builder and. Contractor, do liereby declare the nature of my said
invention to be as follows:-
My invention relates to improvements in the arrangement and construction of
crucible melting furnaces which are heated by the combustion of gaseous fuel. I am
aware that gas furnaces have been employed for melting metal in crucible pots and I
lay no claim to novelty in respect to the employment of gas.
The object of my invention is to simplify the construction and arrangement of a
gas heated melting furnace so that in some cases it may be adapted to the building
and flues of existing crucible melting furnaces of ordinary construction.
I effect this by building the furnace or pot holes in a row, side by side, for working.
one, two or more pots in each hole somewhat similar in plan to an ordinary steel
melting furnace. Instead however, of making the furnace elliptical in shape I make
my improved pot hole with a semi-circular back towards the chimney flue and with a
straight front.
I also construct the bottom of the furnace with what may be called a
hearth of refractory material for the pots to rest upon, instead of the usual arrange-
ment of firebars. In the centre of the hearth near the front I provide an outlet for
the metal and scoria to run through, in case of accident from a cracked or broken
pot. I also provide each pot hole with a suitable cover frame and brick similar to
those ordinarily in use. Along the front of a row of pot. holes so constructed, 1
provide, either in the brickwork, or outside the brickwork, an air box or
Lube and parallel therewith I also provide a gas box or tube, both the air
box and the gas box being provided with valves and with ports or passages
communicating with the interior of each pot hole furnace, these air and gas valves
being actuated by a suitable arrangement of mechanism so that they can be opened
and closed from a convenient position and the quantity of air and gas regulated
according to the requirements of the furnace. I also provide suitable doors for
obtaining access and changing the valves and likewise doors for burning out the tar
in the gas box and tube. The gas I provide from any suitable form of producer and
placed in any convenient position either in or outside the building.
By placing the air and gas box in or alongside the front of the furnace and by
forming the gas and air ports through the brickwork in front of the furnace, the gas
and air become heated before entering the furnace and setting up combustion, the
waste gases pass into the chimney flue in the ordinary way.
In some cases when a melting furnace is specially constructed on my improved
system I arrange for the air passages to run along the back of the pot hole furnace
under the chimney flue with branch passages leading round the outer walls of the
pot hole to the front air box so that a larger amount of heat inay be taken up by the
air and in some cases I make a similar provision by which the gas may lie likewise
heated before entering the combustion chamber or furnace.
It will thus be seen that by my improved arrangement one, two or more pots may
be beated in each hole of a furnace and worked separately from the adjacent furnace

page_text: with gaseous fuel and that by the simple arrangement of heating the air or the gas,
or the air and the gas, no separate regenerators are required and reversing valves are
dispensed with..
By my improved arrangement. I can shut off any pot hole or furnace without
interfering with the effective working of the adjacent furnaces in the series.
Dated this 93rd day of December 1896
I, WILLIAM KIRKHAM, of 22 Brinsworth Street, Attercliffe, Sheffield, in the County
of York, Furnace Builder and Contractor, do hereby declare the nature of my said
invention and in what manner the same is to be performed to be particularly
described and ascertained in. and by the following statement:-
My invention relates to improvements in the arrangement and construction of
crucible melting furnaces which are heated by the combustion of gaseous fuel. I am
aware that gas furnaces have been employed for melting metal in crucible pots and I
lay no claim to novelty in respect to the employment of gas.
The object of my invention is to simplify the construction and arrangement of a
gas heated melting furnace so that in some cases it may be adapted to the building
and flues of existing crucible melting furnaces of ordinary construction.
The nature of my Invention will be better understood on reference to the
Accompanying sheet of Drawings, in which,.
Fig. 1. is a transverse section of my improved furnace taken through the centre of
the pot holes and the waste gas ports on the line A. B. (Fig. 4).
Fig. 2. is likewise a transverse section taken through the air chamber and passages
on the line C. D. (Fig. 4).
Fig. 3. is a plan looking on the floor of the melting furnace, and
Fig. 4. is a sectional plan on the line E. F. Fig. 1.
The same letters refer to similar parts throughout the several views.
I carry out my invention by building the furnace or pot holes, A, in a row, side by
side, for working one, two or more pots in each hole somewhat similar in plan to an
ordinary steel melting furnace, as shewn in Fig. 3. Instead, however, of making the
furnace elliptical in shape I make my improved pot hole with a semi-circular back
towards the chimney flue and with a straight front, as shewn in the sectional plan
Fig. 4, though I do not confine myself to this or any particular shape. I also
construct the bottom of the furnace with what may be called a hearth, B, of refractory
material for the pots to rest upon, instead of the usual arrangement of fire-bars. In
the centre of the hearth near the front I provide an outlet, C, for the metal and scoria
to run through in case of accident from a cracked or broken pot. I also provide
each pot hole with a suitable cover frame and brick similar to those ordinarily in use.
Along the front of a row of pot holes so constructed, I provide, either in the brickwork
or outside the brickwork, an air box or tube, D, and parallel therewith I also provide
a gas box or tube, E, both the air box and the gas box being provided with
valves, F, F, and with ports or passages, G, G¹, communicating with the interior of
each pot hole furnace, these air and gas valves being actuated by a suitable arrange-
ment of mechanism, H, I, so that they can be opened and closed from a convenient
position and the quantity of air and gas regulated according to the requirements of
the furnace. I also provide suitable doors, I, I, for obtaining access and changing
the valves and likewise doors for burning out the tar in the gas box and tube. The

page_text: gas I provide from any suitable form of producer and placed in any convenient
position either in or outside the building.
By placing the air and gas box in or alongside the front of the furnace and by
forming the gas and air ports through the brickwork in front of the furnace,
the gas and air become heated before entering the furnace and setting up
combustion the waste gases pass into the chimney flue, J, in the ordinary way as
indicated by the arrows in Fig. 1.
In some cases when a melting furnace is specially constructed on my improved
systein I arrange for the nir passages, K, K, to run along the back of the pot hole
furnace under the chimney flue with branch passages leading round the outer walls
of the pot hole to the front air box so that a larger amount of heat may be taken up
by the air and in some cases I make a similar provision by which the gas may be
likewise heated before entering the combustion chamber or furnace.
It will thus be seen that by my improved arrangement one, two or more pɔts may
be heated in each hole of a furnace and worked separately from the adjacent furnace
with gaseous fuel and that by the simple arrangement of heating the air or the gas,
or the air and the gas, no separate regenerators are required and reversing valves are
dispensed with.
By my improved arrangement I can shut off any pot hole or furnace without
interfering with the effective working of the adjacent furnaces in the series.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is,
1. In crucible melting furnaces, heated by gas, the arrangement and combination
of parts and appliances by means of which the waste heat from the furnaces may be
utilized in heating tho air or the gas or heating the air and the gas on its passage to
the combustion chamber thereby dispensing with separate or detached regenerator
chambers and also dispensing with the use of reversing valves substantially in the
manner and for the purposes as herein described and illustrated.
Dated this 23rd day of September 1897.
R. HEBER RADFORD,
Agent for the Applicant.