Method of Froducing warding of Calcium
Year: 1899

page_text: Date of Application, 11th July, 1899-Accepted, 12th Aug., 1899
Method of Froducing warding of Calcium
A communication from WILLIAM SMITH HORRY, Electrical Engineer, of Niagara,
New York, United States of America.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, 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:—
The object of the invention is to provide for the production of calcium carbido
of uniform grade and quality and to increase the output of the finished product,
and to these and other ends the invention comprises the improvement hereinafter
described and claimed.
A consider-
In the practice of the invention, buried portions of the charge are reduced
for the production of a pool of calcium carbide. This is done by feeding the
charge around and passing the current between electrodes arranged substantially
parallel and vertical and buried in the charge. The described position of the
electrodes is productive of several beneficial results, for example, it permits of
the feeding of the charge all around them, it protects them from the air, thereby
increasing the length of their lives; it presents their tips in proper relation to
the surface of the pool, and it insures above their tips the presence of a mass
of the incoming charge towards which they direct escaping gases.
able portion of the heat generated is retained and utilized to maintain the pool
of carbide in a molten condition until it spreads laterally beyond the field of
reduction by keeping the charge around and above the electrodes of sufficient
depth for this purpose. An advantage of this is that carbide of calcium is pro-
duced in relatively large cross-sectional area and of substantially uniform quality.
Successive portions of the charge are brought into the field of reduction for the
described treatment by shifting the carbide and charge electrodes vertically with
respect to each other.
The process may be practiced by means of a variety of apparatus of which a
few examples have been illustrated in the accompanying drawings. forming part
hereof and in which
Figures 1, 2 and 3 are elevational views illustrating principally in central
section electric furnaces by means of which the process may be successfully
practiced and clearly explained.
In what is believed to be the best embodiment of apparatus for the practice
of the invention,, there is an open top receptacle, vessel or wall for receiving and
containing the material or charge to be acted upon and for conveying gas
In
through such material or charge. In Fig. 1, 1, is such a receptacle.
Fig. 2, 2, is such a receptacle. In Fig. 3, 3, is such a receptacle.
In each
case the receptacle is open for the escape of gas at its top and it is adapted to
There are also in
contain material or a charge 4, which is to be acted upon.
the furnace pencils P and N, of opposite polarity, or in other words, between
which the current passes, and the circuit, either direct or alternating, is com-
pleted: These pencils extend below the top of the charge and within the
receptacle and they are arranged clear of its side walls, so that their tips may
be deeply buried in the material or charge 4, as shown. Use may also be
made of pencil holders 5, which are located inside of the side walls of tho

page_text: receptacle, so that jets of gas following the pencils and pencil holders do not
escape through the side walls of the receptacle as would be the case if the holders
projected or extended through the side walls. The circuit connections are
indicated at 6 and 7. To strike or start the are, the electrodes are connected
by a high resistance conductor, which may be accomplished by placing between
the pencils. powdered coke or the like and then charging the furnace with the
carbide producing materials. In the subsequent operations, there is produced
a pool 10, of fluid carbide of calcium, which is traversed by the current of
electricity. This pool is at the zone of greatest temperature and its surface is
substantially level, and the material or charge 4, pre-heated by the escaping
gases, falls all round the electrodes into this pool which spreads out as shown,
because the superimposed charge, by reason of its depth, retains a considerable
portion of the heat generated and thereby maintains the pool of carbide in a
molten condition until it spreads laterally beyond the field of reduction.. Thus
the pool substantially fills the receptacle and receives the incoming charge.
Since the top of the pool is lovel, it follows that the pencils should be vertical
and therefore parallel or substantially so and they should also be clear of the
side walls in order to permit the material or charge 4, to fall all round them
into the pool as described. To practice the described process and to cause the
pool to occupy at all tiines the zone of highest temperature and to fill the recep-
tacle with calcium carbide, means which shift the carbide and charge and electrodes
vertically the one in respect to the other should be provided in order to bring
successive portions of the charge into the field of reduction. Such means are
susceptible of different embodiments; for example, in the furnace shown in
Fig. 1, the carbide and part of the charge are shifted vertically (in the sense
that they travel upon the arc of a large circle tangent to the line of the electrodes)
away from or towards the electrodes, and the chamber or receptacle at the left-
hand side of the figure is built up by the addition of suitable side and face plates.
In the furnace shown in Fig. 2, the described movement may be effected because
the bottom 8, is moved vertically. As shown in Fig. 3, the pencils are adjusted
in respect to the receptacle, for example, by moving the receptacle vertically
downward, and parts, as 9, may be added.
In the operation, the pool spreads out laterally and practically fills the recop-
tacle, is substantially maintained in the zone of highest temperature, and receives
the incoming material which falls all round the electrodes, so that the product
is produced under the same conditions, and consequently its grade and quality
are practically uniform.
Having now particularly described and ascertained the nature of the said
invention, as communicated to us by my foreign correspondent, and in what
manner the same is to be performed, I declare that what I claim is;-
The method of making calcium carbide, which consists in arranging electrodes
of opposite polarity in a substantially vertical position and adjacent to cach
other, feeding a suitable charge of raw material around the electrodes, causing
an electric current to flow between the electrodes, thereby reducing adjacent
portions of the charge and producing an initial pool of carbide, keeping the
charge around the electrodes of such depths as to retain a considerable portion
of the heat generated, and thereby maintaining the pool of carbide in a molten
condition until it spreads out laterally beyond the field of reduction, and shifting
the carbide and charge vertically with respect to the electrodes to bring successive
portions of the charge into the field of reduction.
Dated this 10th day of July 1809
BOULT & WADE,
Agents for the Applicant.