Improvements in Methods and Apparatus for. Electro-thermally Treating Materials, more particularly for the Manufacture of Calcium n Carbide and other Carbides, and the Reduction of Ores.
Year: 1898

page_text: Date of Application, 18th Feb., 1898
Complete Specification Left, 4th Nov., 1898-Accepted, 7th Jan., 1899
PROVISIONAL SPECIFICATION.
Improvements in Methods and Apparatus for. Electro-thermally
Treating Materials, more particularly for the Manufacture of
Calcium n Carbide and other Carbides, and the Reduction of Ores.
I, HUDSON MAXIM, Chemist and Mechanical Engineer, of Thurlow Lodge,
377, Norwood Road, London, S.E., do hereby declare the nature of this invention
to be as follows:-
The present invention relates generally to an improved process and apparatus
for electro-thermally treating materials, and has particular reference to the
manufacture of calcium carbide and other carbides and the reduction of orés.
The improved process consists mainly in forming an electric heat zone in a
body.. of materials to be reduced or converted, and as the desired product is
formed gradually moving said heat zone along through the materials to bring
fresh material within said zone. It also consists in forming an electric heat zone
in a body of materials under treatment and in moving the heat zone along trans-
versely to the path of the electric current between the electrodes. It furthermore
consists in employing one or more pairs of parallel electrodes with an inter-
mediate high resistance piece or conductor and as the product is formed moving
the electrodes along transversely to the conductor. It still further consists in
enveloping the electrodes in a carbon sleeve or sleeves and moving the electrodes
or the electrodes and sleeve with respect to the other sleeve; in providing an
easily breakable high resistance piece or transverse conductor; in providing a
movable furnace or crucible for the body of material to be treated adapted to be
moved into and out of position with respect to the electrodes, and in many other
provisions for economically and conveniently working and manipulating the pro-
cess and apparatus.
In practically carrying out these improvements any desired arrangement of
furnace or crucible and form of electrodes may be employed, but I prefer to
use a structure in which the electrodes may be moved into position in a removable
furnace and which may be gradually withdrawn or retreated from the furnace
in such manner that the electric heat zone may be moved through the furnace
as the material is converted, and when the desired product is formed, wholly
withdrawing the electrodes from the crucible or furnace, so that the latter may
be moved to one side to allow the product to cool and be removed and permit
another crucible or furnace to take its place so that the operation may be con-
tinued without unnecessary loss of time. With the furnace may be arranged
a heater for preliminarily heating the material be treated before it is charged
into the furnace or
in
crucible, and
SO heating the material the
cor bustible gases rising therefrom, and from the furnace or crucible may
be burned in connection with heated air to aid in raising the temperature of the
said material. The invention is susceptible of various modifications as will be
hereinafter explained.

page_text: In one form of the invention the furnace structure of highly refractory
material, consists of an end wall arranged to support one or more pairs of
electrodes, for instance three pairs; a top portion arranged to close the upper
portion of the furnace or crucible proper, and another end wall more or less
open and forming a partial support for the top portion. Such a structure pro-
vides open sides of such width and height as to permit the furnace or crucible
to be moved into position, and then when more or less of its contained material
has been reduced or converted, moved out of the structure to permit another
furnace or crucible to be moved into position to replace that which was pre-
viously in place. To render these furnaces or crucibles easy of movement, they
may be mounted on wheels, upon a track extending through the structure; and
the furnaces or crucibles may be moved along this track in any suitable manner
either manually or by any, suitable power.
The pairs of electrodes arranged parallel to one another are mounted in the
end wall of the structure so as to be capable of being moved into and out of the
furnace or crucible, the wall of the furnace or crucible being properly perforated
in line with the electrodes to permit their insertion and withdrawal.
Each of the electrodes are supported and moved longitudinally with respect to
carbon sleeves or tubular electrodes which are directly supported by the end wall
of the structure; suitable leads or wires being connected with said sleeves, and
extending to a suitable generator for supplying the electric current needed in
the furnace.
In some instances, the electrodes may each be received within an intermediate
carbon sleeve or tubular electrode, which extends a considerable distance into
the furnace so as to support the inner portion thereof and prevent them from
becoming unduly heated or destroyed; the sleeves being arranged for longitudinal
movement, both with respect to the electrodes themselves and to the outermiost
sleeves.
To insure perfect electrical contact between the sleeves and the electrodes,
the sleeves may be counterbored and filled with a compact body of pulverised
carbon.
The forms of the electrodes may be either solid or hollow, and when hollow,
may be filled with powdered carbonaceous material, such as coal dust, and this
carbon may be forced through the hollow electrode so as to be fed over the
extreme end thereof and thus aid in preventing its too rapid destruction. In
connection with the pairs of electrodes, there will be provided a high resistance
piece or conductor of plate-form entered through openings in the opposite end
of the furnace or crucible against the ends of the pairs of electrodes, to form a
transverse and initial conductor for the current passing from one electrode to the
other, which by the passage of the electric current will provide a body of fused or
highly incandescent material to start the operation. As soon as the product
commences to be formed this conductor will become dissipated and replaced by
the fused or highly incandescent product, which, being a conductor, will con-
tinue to ensure unbroken passage of the current from one electrode to the other.
As the electrodes are more or less gradually retreated from the incandescent
portion and at the same time somewhat attenuating such portion, it will be
brought into contact with the fresh adjacent portions of the material under
treatment, so that a continuing incandescent conductor is provided which con-
stantly forms added fresh product integral with the previously formed product,"
with the result that a slab of the desired product will have been made and ex-
tended through the furnace or crucible as the ends of the electrodes approach
the inner wall of the furnace. When the electrodes are wholly withdrawn from
the furnace or crucible, the latter will be moved outward from the structure, the
formed product allowed to cool, and be removed at the pleasure of the attendant
Any suitable means may be provided for moving the electrodes through the
furnace at such speeds as may be found desirable, and means will also be pio-

page_text: vided, where one or more carbon sleeves are also used in connection with elec-
trodes, for moving them. One such means may consist of suitably mounted
screw rods, capable of being turned by hand in supporting nuts, the inner ends
of the rods being connected to the electrodes and to the sleeves, so that by turn-
ing the screw rods the electrodes and sleeves may be moved along and through
the furnace in the act of placing them in operative position for the start of the
operation, and in the act of withdrawing or retreating them as the operation
continues, and finally removing them wholly from the furnace or crucible at the
completion of the operation. To facilitate the entire removal or replacing of the
electrodes the screw rods may engage with removable heads on the ends of
the electrodes; or these heads may have removable screw-threaded plugs to allow
disconnection of the screw rods from the electrodes.
Instead of the single leads or wires before described, extending from a single
generator, and such leads extending to one of the sleeves, depending upon close
electrical contact between the electrode and the sleeves and between the sleeves
themselves, for the passage of the current, it is obvious that each of the sleeves,
or one or more of them, and the electrodes, may each have independent connec-
tions with the generator, or with independent generators, or with the different
phases of a multi-phase generator. Where such an arrangement of circuits is
employed, it is obvious that an accumulated electric current is provided for the
electrodes, so that increased energy is had, and economy of current obtained.
Where a sufficiently high temperature is formed in the furnace or crucible to
effect complete fusion of the product, such fused product may, while in its melted
condition, be tapped out of the furnace into a separate receptacle or mold, and
when so tapped there may be employed a pair of electrodes in the form of a
plug, stopping an opening or openings in the furnace wall, which, when in posi-
tion, may be in circuit with an electric generator so that they will provide a zone
of electric heat immediately adjacent to the tapping off openings to aid in keeping
the products in a molten condition; and when withdrawn, permit such molten
product to flow or be discharged from the furnace.
The movable furnaces or crucibles, as before mentioned, will be open at their
tops, so as to permit the feed of a body of material thereinto to more or less
fill them. This feed of materials may be had in a separate structure, or in the
same structure, and may take place as soon as the empty furnace or crucible
arrives in position in the structure. For this purpose, the structure may sup-
port a preliminary heater having a chamber capable of containing a quantity of
the material, such for instance as carbonate of lime and coal, to be treated, and
arranged to be discharged through a valved opening in the top of the structure,
in such quantities as the attendant may desire. The walls of this preliminarily
heating chamber will be formed of some suitable high refractory material, such
as magnesite, or the like, and this, in turn, will be surrounded with another
structure of refractory material, providing an intermediate combustion space for
the burning of any suitable fuel to produce the desired heat therein for com-
munication to the material being preliminarily heated. This outer structure,
in turn, will be encased by a metal jacket, and the whole otherwise encased in
some non-conductor of heat.
As the material being preliminarily heated will evolve more or less gas, such
as carbonic oxide, and other combustible gases, according to the nature of the
material being heated which gases and vapors may be led off by a pipe to an
injector or burner leading to the intermediate burning space, a blast of heated
air being supplied thereto to aid combustion. The spent gases or products of
the burned fuel may be led off from the combustion space and conducted to an
air heater to raise the temperature of the air as high as possible before passing
to the burner; or the hot gases themselves rising from the material being pre-
liminarily heated, may some of them be conducted to a burner in the air
heater and burned therein, for the purpose of heating the air on its way to the
other burner. The feed of materials into the furnace or crucible may be con-

page_text: trolled by two valves situated a distance apart, so that limited quantities of the
material may be charged at a time. The combustible gases accumulating in
the space between the valves may be admitted by an opening and burned in the
combustion space before referred to, or may be led by a pipe to the burner.
The high resistance piece or conductor before referred to as being in plate
form, may be transversely corrugated or grooved, or thinned down in places, so
as to facilitate the breaking off of that portion of it in immediate contact with
the carbide or other material that has been formed. The plate form of this con-
ductor facilitates. its introduction and contact with the ends of the electrodes in
starting the operation.
Means may be provided for more or less cooling the carbon sleeves and elec-
trodes as they are gradually withdrawn from the furnace or crucible, and for
this purpose a circulation of water may be had in more or less close contact
with the sleeves to lower their temperature as much as possible; and this cooling
may be effected by a series of vertical pipes or tubes built in the end of the
structure on either side of the sleeves, connected with a supply of cold water,
and having a lead-off pipe, for insuring the circulation.
The structure may be furthermore modified by providing a plurality of elec-
trodes in connection a single common electrode. Such an arrangement will
form a wide slab of the desired product; which instead of being lifted out of the
furnace or crucible may be drawn outward through an opening in one of its
sides, and in such case, the electrodes need not be wholly removed or withdrawn
from the crucible, and the latter may instead of being movable be more or less
permanent.
In a further modified form of the apparatus the movable furnace or crucible,
instead of moving transversely to the longitudinal axis of the electrodes may
have its track and track wheels arranged to permit its entrance into the struc-
ture and removable therefrom in a direction in line with such longitudinal axis,
and in such case the structure will have a single open end.
Dated this 18th day of February 1898.
Improvements in Methods and Apparatus for Electro-thermally
Treating Materials, more particularly for the Manufacture of
Calcium Carbide and other Carbides, and the Reduction of Ores.
I, HUDSON MAXIM, Chemist and Mechanical Engineer, of 47, Effra Road,
Brixton, London, S.W., at present residing at New York City, U.S.A. (Post
Office Box 2488), late of Thurlow Lodge, 377, Norwood Road, London, S.E., 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:
A~
The present invention relates generally to an improved process and apparatus
for electro-thermally treating materials, and has particular reference to the
manufacture of calcium carbide and other carbides and the reduction of ores..
The improved process consists mainly in forming an electric heat zone in a
body of materials to be reduced or converted, and as the desired product is
formed gradually moving said heat zone along through the materials to bring
fresh material within said zone. It also consists in forming an electric heat zone
in a body of materials under treatment and in moving the heat zone along trans-

page_text: versely to the path of the electric current between the electrodes. It furthermore
consists in employing one or more pairs of parallel electrodes with an inter-
mediate high resistance piece or conductor and as the product is formed moving
the electrodes along transversely to the conductor. It still further consists in
enveloping the electrodes in a carbon sleeve or sleeves and moving the electrodes
or the electrodes and sleeve with respect to the other sleeve; in providing an
easily breakable high resistance piece or transverse conductor; in providing a
movable furnace or crucible for the body of material to be treated adapted to be
moved into and out of position with respect to the electrodes, and in many other
provisions for economically and conveniently working and manipulating the pro-
cess and apparatus.
+
In practically carrying out these improvements any desired arrangement of
furnace or crucible and form of electrodes may be employed, but I prefer to
use a structure in which the electrodes may be moved into position in a removable
furnace and which may be gradually withdrawn or retreated from the furnace
in such manner that the electric heat zone may be moved through the furnace
as the material is converted, and when the desired product is formed, wholly
withdrawing the electrodes from the crucible or furnace, so that the latter may
be moved to one side to allow the product to cool and be removed and permit
another crucible or furnace to take its place so that the operation may be con-
tinued without unnecessary loss of time. With the furnace may be arranged
a heater for preliminarily heating the material to be treated before it is charged
into the furnace or crucible, and in SO heating the material the
combustible gases rising therefrom and from the furnace or crucible may
be burned in connection with heated air to aid in raising the temperature of the
said material. The invention is susceptible of various modifications as will be
hereinafter explained.
In one form of the invention the furnace structure of highly refractory
material, consists of an end wall arranged to support one or more pairs of
electrodes, for instance three pairs; a top portion arranged to close the upper
portion of the furnace or crucible proper, and another end wall more or less
open and forming a partial support for the top portion. Such a structure pro-
vides open sides of such width and height as to permit the furnace or crucible
to be moved into position, and then when more or less of its contained material
has been reduced or converted, moved out of the structure to permit another
furnace or crucible to be moved into position 'to replace that which was pre-
viously in place. To render these furnaces or crucibles easy of movement, they
may be mounted on wheels, upon a track extending through the structure; and
the furnaces or crucibles may be moved along this track in any suitable manner
either manually or by any suitable power.
The pairs of electrodes arranged parallel to one another are mounted in the
end wall of the structure so as to be capable of being moved into and out of the
furnace or crucible, the wall of the furnace or crucible being properly perforated
in line with the electrodes to permit their insertion and withdrawal.
Each of the electrodes are supported and moved longitudinally with respect to
carbon sleeves or tubular electrodes which are directly supported by the end wall
of the structure; suitable leads or wires being connected with said sleeves, and
extending to a suitable generator for supplying the electric current needed in
the furnace.
intermediate
In some instances, the electrodes may each be received within an
carbon sleeve or tubular electrode, which extends a considerable distance into
the furnace so as to support the inner portion thereof and prevent them from
becoming unduly heated or destroyed; the sleeves being arranged for longitudinal
movement, both with respect to the electrodes themselves and to the outermost
sleeves.
To insure perfect electrical contact between the sleeves and the electrodes,

page_text: the sleeves may be counterbored and filled with a compact body of pulverised
carbon.
The forms of the electrodes may be either solid or hollow, and when hollow,
may be filled with powdered carbonaceous material, such as coal dust, and this
carbon may be forced through the hollow electrode so as to be fed over the
extreme end thereof and thus aid in preventing its too rapid destruction. In
connection with the pairs of electrodes, there will be provided a high resistance
piece or conductor of plate-form entered through openings in the opposite end
of the furnace or crucible against the ends of the pairs of electrodes, to form a
transverse and initial conductor for the current passing from one electrode to the
other, which by the passage of the electric current will provide a body. of fused or
highly incandescent material to start the operation. As soon as the product
commences to be formed this conductor will become dissipated and replaced by
the fused or highly incandescent product, which, being à conductor, will con-
tinue to ensure unbroken passage of the current from one electrode to the other.
As the electrodes are more or less gradually retreated from the incandescent
portion and at the same time somewhat attenuating such portion, it will be
brought into contact with the fresh adjacent portions of the material under
treatment, so that a continuing incandescent conductor is provided which con-
stantly forms added fresh product integral with the previously formed product,
with the result that a slab of the desired product will have been made and ex-
tended through the furnace or crucible as the ends of the electrodes approach
the inner wall of the furnace. When the electrodes are wholly withdrawn from
the furnace or crucible, the latter will be moved outward from the structure, the
formed product allowed to cool, and be removed at the pleasure of the attendant.
Any suitable means may be provided for moving the electrodes through the
furnace at such speeds as may be found desirable, and means will also be pro-
vided, where one or more carbon sleeves are also used in connection with elec-
trodes, for moving them. One such means may consist of suitably mounted
screw rods, capable of being turned by hand in supporting nuts, the inner ends
of the rods being connected to the electrodes and to the sleeves, so that by turn-
ing the screw rods the electrodes and sleeves may be moved along and through
the furnace in the act of placing them in operative position for the start of the
operation, and in the act of withdrawing or retreating them as the operation
continues, and finally removing them wholly from the furnace or crucible at the
completion of the operation. To facilitate the entire removal and replacing
of the electrodes the screw rods may engage with removal screw-threaded plugs
to allow disconnection of the screw rods from the electrodes.
Instead of the single leads or wires before described, extending from a single
generator, and such leads extending to one of the sleeves, depending upon close
electrical contact between the electrode and the sleeves and between the sleeves
themselves, for the passage of the current, it is obvious that each of the sleeves,
or one or more of them, and the electrodes, may each have independent connec-
tions with the generator, or with independent generators, or with the different
phases of a multi-phase generator. Where such an arrangement of circuits is
employed, it is obvious that an accumulated electric current is provided for the
electrodes, so that 'increased energy is had, and economy of current obtained.
Where a sufficiently high temperature is formed in the furnace or crucible to
effect complete fusion of the product, such fused product may, while in its melted
condition, be tapped out of the furnace into a separate receptacle or mold, and
when so tapped there may be employed a pair of electrodes in the form of a
plug, stopping an opening or openings in the furnace wall, which, when in posi-
tion, may be in circuit with an electric generator so that they will provide a zone
of electric heat immediately adjacent to the tapping off openings to aid in keeping
the products in a molten condition; and when withdrawn, permit such molten
product to flow or be discharged from the furnace.
The moveable furnaces or crucibles, as before mentioned, will be open at their

page_text: tops, so as to permit the feed of a body of material thereinto to more or less
fill them. This feed of materials may be had in a separate structure, or in the
same structure, and may take place as soon as the empty furnace or crucible
arrives in position in the structure. For this purpose, the structure may sup-
port a preliminary heater having a chamber capable of containing a quantity of
the material, such for instance, as carbonate of lime and coal, to be treated, and
arranged to be discharged through a valved opening in the top of the structure,
in such quantities as the attendant. may desire. The walls of this preliminarily
heating chamber will be formed of some suitable high refractory material, such
as magnesite, or the like, and this, in turn, will be surrounded with another
structure of refractory material, providing an intermediate combustion space for
the burning of any suitable fuel to produce the desired heat therein for com-
munication to the material being preliminarily heated. This outer structure,
in turn, will be encased by a metal jacket, and the whole otherwise encased in
some non-conductor of heat.
As the material being preliminarily heated will evolve more or less gas, such
as carbonic oxide, and other combustible gases, according to the nature of the
material being heated, which gases and vapors may be led off by a pipe to an
injector or burner leading to the intermediate burning space, a blast of heated
air being supplied thereto to aid combustion. The spent gases or: products of
the burned fuel may be led off from the combustion space and conducted to an
air heater to raise the temperature of the air as high as possible before passing
to the burner; or the hot gases themselves rising from the material being pre-
liminarily heated, may some of them be conducted to a burner in the air
heated and burned therein, for the purpose of heating the air on its way to the
other burner. The feed of materials into the furnace or crucible may be con-
trolled by two valves situated a distance apart, so that limited quantities of the
material may be charged at a time. The combustible gases accumulating in
the space between the valves may be admitted by an opening and burned in the
combustion space before referred to, or may be led by a pipe to the burner.
The high resistance piece or conductor before referred to as being in plate
form, may be transversely corrugated or grooved, or thinned down in places;,"so
as to facilitate the breaking off of that portion of it in immediate contact with
the carbide or other material that has been formed. The plate form of this con-
ductor facilitates its introduction and contact with the ends of the electrodes in
starting the operation.
Means may be provided for more or less cooling the carbon sleeves and elec-
trodes as they are gradually withdrawn from the furnace or crucible, and for
this purpose a circulation of water may be had in more or less close contact
with the sleeves to lower their temperature as much as possible; and this cooling
may be effected by a series of vertical pipes or tubes built in the end of the
structure on either side of the sleeves, connected with a supply of cold water,
and having a lead-off pipe, for insuring the circulation.
The structure may be furthermore modified by providing a plurality of elec-
trodes in connection with a single common electrode. Such an arrangement will
form a wide slab of the desired product: which instead of being lifted out of the
furnace or crucible may be drawn outward through an opening in one of its
sides, and in such case, the electrodes need not be wholly removed or withdrawn
from the crucible, and the latter may instead of being movable be more or less
permanent.
In a further modified form of the apparatus the movable furnace or crucible,
instead of moving transversely to the longitudinal axis of the electrodes may
have its track and track wheels arranged to permit its entrance into the struc-
ture and removable therefrom in a direction in line with such longitudinal axis,
and in such case the structure will have a single open end.
In the accompanying drawing I have shown how my said invention may be con-
veniently and advantageously carried into practice.

page_text: : Fig. 1 is a vertical section, and
Fig. 2 a horizontal section showing one form of my improved apparatus.
Fig. 3 is a horizontal section of a modification of my inventions showing the
use of three electrodes.
Referring to the drawings, the furnace structure 1, encloses the furnace
hearth 2, in which the materials y, cover two or more electrodes 3, 3.
The electrodes preferably extend through an end wall of the furnace and
outside of the furnace are insulated and fixed on a frame 5, which is adapted
to be, together with the electrodes, moved toward and from the furnace by a
switchable screw 6, operated by a hand wheel or crank 7.
It will be seen from the drawings that the electrodes extend a considerable
distance in the furnace chamber and at their free ends are in contact with a
high resistance bar, rod, or filament 4, preferably of carbon which lies surrounded
by the material and by the passage of an electric current through the electrodes
is heated to intense incandescence, converting the surrounding material into
carbide in the well-known manner. The carbide thus formed acts as an incan-
descent conductor which being molten maintains efficient contact with the
electrodes as they are withdrawn through the material, forming at the same
time a horizontal sheet of carbide that is continually enlarged on its edge
between the electrodes.
When the electrodes have been withdrawn to their outward position, the
current of electricity is stopped, the sheet of carbide is allowed to cool, and is
then taken out by the door 10. The electrodes may be then advanced and
the operation repeated after the incandescent rod 4 is replaced. It is obvious
that the solid form of rod shown in Figs. 1 and 2 may be replaced without im-
pairing the operation of the furnace, by the conductor 14 of broken pieces of
carbon or other suitable material as in Fig. 3. The electrodes 3 are connected
with a generator of electricity by means of a clamp 8, and cable 9, or other
suitable device. A direct or an alternating current may be used, but preferably
the latter.
Material may be supplied to the furnace through a hopper or opening 11 on
the top of the furnace structure and the gases evolved by the treatment of the
materials may escape by the opening or stack 12.
I have found that there is a practical limit to the size of electrodes and
furnace when only two electrodes are employed, as in Figs. 1 and 2, but the
furnace may be increased greatly in size and capacity for producing by providing
for the use of three or more electrodes arranged substantially on a horizontal
plane as in Fig. 3. By this method a multiphase current, say three-phase can
be used, and while the furnace capacity for producing is doubled, the size,
number and quantity of electrodes, cables, and the like is increased only one-half
as much as before.
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. The herein described process of electro-thermally treating materials, which
consists in passing an electric current through substantially parallel electrodes,
and from one electrode to the other through an intermediate conductor, and then
withdrawing the electrodes through material surrounding the electrodes in a
direction transverse to the passage of the current through the intermediate con-
ductor, whereby the heating field is made to advance upon fresh materials.
2. The herein described process of electro-thermally treating materials, which
consists in passing a heating field by means of an incandescent electric con-
ductor through a body of materials in a direction transverse to the path of the
electric current through the conductor.
3. The herein described process of electro-thermally treating materials, which
consists in passing an electric current through a body of materials to heat the

page_text: materials, and then advancing the path of the electric current through the
materials in a direction transverse to the path of the electric current.
4. The herein described process of electro-thermally treating materials, which
consists in surrounding substantially parallel electrodes with a body of the
materials to be treated, passing an electric current from one electrode to the other
through the materials, and gradually moving the electrodes in a longitudinal
direction, whereby the path of the electric current is correspondingly altered.
5. The herein described process of electro-thermally treating materials, which
consists in passing independent electric currents through a body of the material,
and advancing the path or paths of the electric currents through the materials
in a direction transverse to the path of the electric currents.
6. The herein described process of electro-thermally treating materials, which
consists in passing independent electric currents through the material by a con-
ductor common to two or more of the currents, and advancing the path through
the material in a direction transverse to the path of the electric current through
the common conductor.
7. The herein described process of electro-thermally treating electrically non-
conducting materials, which consists in converting a portion of the materials
into a conducting medium, and continuously converting fresh materials into a
conducting medium in a direction transverse to the passage of the electric
current through the conducting medium.
8. The herein described process of electro-thermally treating materials, which
consists in fusing a portion of the materials, passing an electric current through
the fused body, and advancing the zone of fusion in a direction transverse to the
passage of the electric current through the fused body.
9. In the manufacture of calcium carbide, the herein described process, which
consists in passing an electric current through a carbide conductor, altering the
path of the electric current through the conductor in a direction transverse to
the passage of the electric current, whereby the conductor is unequally heated
in a direction desired for the treatment of further materials.
10. The herein described process of making calcium carbide, which consists in
forming independent strata of carbide in a body of carbide-forming materials,
separated by an intervening strata of unconverted carbide-forming material.
11. The herein described process of making calcium carbide which consists in
forming a block of calcium carbide by independent electric currents passed
through different portions of a body of carbide and in the direction of the zone
of conversion of the carbide-forming materials into carbide and advancing the
paths of the electric current in the said direction.
12. In an apparatus for electro-thermally treating materials, the combination
of electrodes adapted to enter and be withdrawn from the crucible in a direction
transverse to the movement of the crucible.
13. In an apparatus for electro-thermally treating materials, the combination
of electrodes adapted to enter and be withdrawn from a crucible in a direction
longitudinal to the movement of the crucible.
14. The herein described process of electro-thermally treating materials, which
consists in passing polyphase electric currents through the material by a con-
ductor common to two or more of the phases and advancing the path through the
material in a direction transverse to the path of the electric current through
the common conductor.
T
the 5th
Ontahan 1000