Improvements in the Production of Calcium Carbide.
Year: 1895

page_text: Date of Application (in United Kingdom), 15th Aug., 1895
Complete Specification Left, 14th May, 1896-Accepted, 20th June, 1896
Improvements in the Production of Calcium Carbide.
I THOMAS LEOPOLD WILLSON of Plaza Hotel, Fifth Avenue, corner Fifty-
ninth Street, New York City, in the United States of America, Electrical
Engineer, do bereby declare the nature of this invention to be as follows:
This invention relates to the production of calcium carbide.
According to my invention I proceed as follows:-—
I take very finely divided coke and lime, mechanically reduced to a pulverulent
condition, and I mingle them thoroughly mechanically in the proportion of
35 per cent. of coke and 65 per cent. of lime. I then subject them to the action of
the electric current in a furnace such as that shown in the accompanying drawing,
which is a vertical section and in which A represents an enclosing brickwork; Ban
internal lining, preferably of carbon, which, though preferable is not in all cases
Decessary; Cone of the conducting poles, by preference of broken carbon;
Da
removable pole of compacted carbon; E a tap hole for removing the melted product
if desired; F adjusting mechanism for raising the carbon pole D; and G an
alternating current dynamo, which may therefore be made commutatorless.
In starting this furnace the carbon pole D and the conducting bodies C are
connected to the poles of an alternating current dynamo having a mean potential,
say of 55 volts, and sufficient amperage to produce the amount of material required,
having regard to the size of the furnace. Using, for instance, a pole having eight
inches on the side, an amperage of about 1500 is desirable. Under these conditions,
by reason of the alternation of the current, a feeding-in of the mingled lime and
carbon between the poles is effected to an extent which does not occur when a
direct current is used. Furthermore it has been generally understood that the
production of calcium carbide was due to an electrolytic action, and not to a
smelting action. I have demonstrated that the action is purely a smelting action
under the conditions of the process here described. Furthermore that the block of
molten calcium carbide which forms beneath the elevating pole is itself a good
conductor of electricity, and can be built up from the bottom to any desired height
without preventing the operation of the process. A height for instance of two or
more feet is entirely practicable in the apparatus above described. If preferred of
course the fused calcium carbide may be tapped out as the same is formed, in the
ordinary way as applied to iron and steel. The liquid calcium carbide thus
produced, when allowed to cool, crystallizes, and when broken exhibits bluish or
purplish iridescent surfaces. By this process likewise the yield of calcium carbide
per electric horse power is almost doubled over a process of using a direct current,
which is evidently a matter of the utmost importance, while at the same time the
process proceeds uniformly and without break, by reason of the substantial uniform
feeding in of the material.

page_text: It is essential in order to produce the new material here described, to have the
Jime and coke very finely divided. This is done by a powdering machine and then
the powdered lime and coke are thoroughly mingled by a grinder or mixer so as to
bring these bodies into most intimate contact. The action of the alternating
current is likewise essentially different from that of a direct current, producing
a series of explosions, the effect of which seems to be to feed the pulverized
material into the arc. This is very important in accomplishing a rapid and
uniform conversion.
I do not in the present application for Patent include the use of an alternating
current in combination with mingled carbon as applied to other metallic oxides, as
I intend to make a separate application therefor.
Dated this 15th day of August 1895.
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.
Improvements in the Production of Calcium Carbide.
I, THOMAS LEOPOLD WILLSON of Plaza Hotel, Fifth Avenue, corner Fifty-
ninth Street, New York City, in the United States of America, Electrical
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This invention relates to the production of calcium carbide.
According to my invention 1 proceed as follows:-
I take very finely divided coke and lime, mechanically reduced to a pulverulent
condition, and I mingle them thoroughly mechanically in the proportion of,
35 per cent. of coke and 65 per cent. of lime. I then subject them to the action of
the electric current in a furnace such as that shown in the drawing left with my
Provisional Specification, which is a vertical section and in which A represents an
enclosing brickwork; B an internal lining, preferably of carbon, which, though
preferable is not in all cases necessary; C one of the conducting poles, by
preference of broken carbon; D a removable pole of compacted carbou; E a tap
hole for removing the melted product if desired; F adjusting mechanism for raising
the carbou pole D; and G an alternating current dynamo, which may therefore be
made commutatorless.
of
In starting this furnace the carbon pole D and the conducting bodies C are con-
nected to the poles of an alternating current dynamo having a mean potential, say
55 volts, and sufficient amperage to produce the amount of material required,
having regard to the size of the furnace. Using, for instance, a pole having eight
inches on the side, an amperage of about 1500 is desirable. Under these conditions,
by reason of the alternation of the current, a feeding-in of the mingled lime and
carbou between the poles is effected to an extent which does not occur when a direct
current is used. Furthermore it has been generally understood that the production
of calcium carbide was due to an electrolytic action, and not to a smelting action,
I have demonstrated that the action is purely a smelting action under the conditions
of the process here described. Furthermore that the mass of molten calcium
carbide which forms beneath the elevating pole is itself a good conductor of
electricity, and can be built up from the bottom to any desired height without
preventing the operation of the process. A height for instance of two or more feet
is entirely practicable in the apparatus above described. If preferred the fused
calcium carbide may if under any conditions it be found practicable, be tapped out
as the same is formed, in the ordinary way as applied to iron and steel. The
liquid calcium carbide produced by this process, when allowed to cool, crystallizes,

page_text: and when broken exbibits bluish or purplish iridescent surfaces. By this process
likewise the yield of calcium carbide per electric horse power is considerably
increased over a process of using a direct current, which is evidently a matter
of the utmost importance, while at the same time the process proceeds uniformly
and without break, by reason of the substantially uniform feeding in of the
material.
It is essential in order to best produce the material here described, to have the
lime and coke very finely divided. This is done by a powdering machine and then
the powdered lime and coke are thoroughly mingled by a grinder or mixer so as to
bring these bodies into most intimate contact. The action of the alternating
current is essentially different from that of a direct current, producing a series of
explosions or pulsations, the effect of which seems to be to feed the pulverized
material into the arc. This is very important in accomplishing a rapid and uniform
conversion.
The reversals of the current may be satisfactorily run at about fifty a second,
and the serious difficulty of feeding in between the poles is overcome by this
process.
I do not in the present application for Patent include the use of an alternating
current in combination with mingled carbon as applied to other metallic oxides, as
I have made a separate application for Letters Patent therefor.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
The production of calcium carbide by feeding pulverulent and thoroughly
commingled carbon and lime into an arc formed by an alternating electric current
of suitable frequency, and by converting the same into calcium carbide by means of
such arc, substantially as described.
31
.
2000
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.