Improvements in and relating to Electrio Furnaces.
Year: 1896

page_text: Date of Application, 17th Sept., 1896-Accepted, 7th Nov., 1896
COMPLETE SPECIFICATION.
Improvements in and relating to Electrio Furnaces.
I, JAMES ALBERT DEUTHER, a citizen of the United States of America,
residing at 114 Purchase Street, in the City of Boston, County of Suffolk and
State of Massachusetts, United States of America, Gentleman, 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:-
My invention relates to improvements in electric furnaces for the manufacture
of calcium carbide and for the reduction of refractory and other metallic compounds,
and its main object is to facilitate the bringing of the material to be acted upon
directly within the influence of the electric arc formed between two separated
electrodes, through which the electric current passes.
In electric furnaces the heat generated between two separated electrodes is
sufficiently intense within the field of the arc formed between said electrodes for
smelting, while outside the influence of the arc the heat is not sufficient for such
purpose.
For electric furnaces to be economical and practical, the heat incident upon the
formation of the arc should continuously act upon the material to be treated, and
said material should be introduced or fed directly within the influence of the arc,
and further, when such material has been properly affected by the heat incident
upon the formation of the arc, new material should be supplied for treatment and
no time should be lost in introducing the proper amount of new material required.
Now, while it is useful to surround the electrodes when in action with some
material to prevent the heat incident upon the are from affecting the walls and
other parts of the furnace, yet it is at the same time wasteful to have more material
than is necessary to prevent excessive radiation of heat from the arc.
For instance, in the process of making calcium carbide in electric furnaces-
this compound, when pure, is composed of metallic calcium and carbon, the metallic
calcium required being obtained preferably from oxide of calcium and the carbon
from coke. Now, in order to bring about the chemical formation of calcium
carbide from said materials, the heat of the arc is necessary, and while it may be
of very high temperature at the seat of the arc, yet the temperature a few inches
from the seat of said arc, is not high enough to produce a comparatively pure
product. This lower temperature, however, at a few inches from the seat of the
arc is sufficient to cause combustion of the carbon mixed with the oxide of calcium,
and probably volatilise the lime, and before this so called burnt out mixture of
oxide of calcium can again be utilized or properly treated by the arc to produce
calcium carbide, additional carbon must be added to take the place of the carbon
burnt out, consequently, to avoid the action of burning out the carbon, as above
described, it is necessary that the material to be treated should be introduced or
fed directly within the influence of the arc, so as to be acted upon in a comparatively
short time.
Now it is the purpose and object of my invention to introduce or feed directly
within the influence of the arc, the material to be treated, and thus prevent said
material having the carbon burned out in the manner above described.
In the accompanying drawing which illustrates a construction embodying my
invention-
Figure 1 is a vertical cross section through an electric furnace, and showing the
opposite electrodes in full lines.

page_text: Figure 2 is a similar view but showing the upper electrode moved to a different
position from that shown in Figure 1.
Like letters of reference refer to like parts throughout the several views.
The electric furnace A is constructed of fireproof material A', and in practice
may have a suitable outlet through which the product can be removed. Located
at the bottom of the furnace and surrounded by the brick A³ is the electrode B of
conducting material and connected to one pole of an electric generator by a
suitable wire B'. Located above the lower electrode B is a movable and
oscillatory electrode C, preferably of lesser diameter than the electrode B and
which is connected to the other pole of the electric generator by a suitable wire C.
This upper electrode C is suspended above the electrode B and is supported in its
suspended position by means of the rod C 2 connected to the top of the electrode C,
and to said rod C there is pivotally connected at C another rod C which extends
upwardly through the cross beam D, supported by the side beams D', and the
upper end of said rod C projects through the cross bar C, and a suitable nut C
holds said rod C connected to the cross-bar C. Through the opposite end of the
cross bar a lifting screw C7 working in the nut C is arranged and its lower
end works in a socket C8 on said cross beam D, and by means of said lifting
screw C the electrode C is raised and lowered by means of the connections above
described.
Secured to the top of the electrode C is a rectangular receptacle E, provided
with an opening E' in its bottom, and located near the edge of the top of the
clectrode C. Within said receptacle C there is arranged a box F of suitable size
with the opening F in its bottom, and said box F is adapted to reciprocate within
the receptacle E. Connected to one side of the box F, is a rud F, and said rod
extends out through the end E2 of the receptacle E, and on its outer end there is
provided a roller F which bears against one of the side beams D', and around that
portion within the receptacle E there is arranged a spiral spring F which is
connected at one end to the box F, and the opposite end is connected to the end E
of the receptacle E.
At about the center of the rod C there is pivotally connected at G the rod G,
which passes through and is supported in the slot D in the side beam D', and is
provided at its outer end with the handle G2, and by means of said handle G the
upper electrode C can be moved from its vertical position as shown in Figure 2.
Now assuming that the rod G has been operated to move the upper electrode C
to the position shown in Figure 2, it will be noted in said movement, that the
rod moves the box F to the position shown, so that the opening F in said
box F registers with the opening El in the receptacle E; consequently, the
material to be treated, when it is placed in the box F, by hand or by any
suitable mechanism, drops on to the top of the lower electrole B, and ís
designated in the drawing by the letter H, and it is thus within the influence
and in the path of the heat consequent upon the formation of the are between B
and C when the electrode C recovers its vertical position as shown in Figure 1,
or is pushed in an opposite direction, and by this pendulum or oscillatory movement,
the material is dropped down upon the lower electrode B and brought at will
within the influence of the arc.
box F, and at the other end is connected to the end E of the receptacle E, it is
As the spring F is connected at one end to the
obvious, as the rod F2 pushes the box F to the position shown in Figure 2, and
thereby puts the spring Funder tension, that said electrode C resumes its vertical
position, the spring 1, by reason of said tension, will move the box F to the
position shown in Figure 1, when fresh material can be placed in said box F for
the next operation.
The movement given to the upper electrode C as shown in Figure 2, causes the
are to move as required from left to right or vice versa, across the electrode B and
induces a smelting process, consequently it is possible to have the are formed act
continuously, and positively on the fresh material, and as the smelted product,
which is desiguated by the letter H is a conductor, it is therefore clear that the

page_text: material dropped onto the electrode B from the box F is within the influence of
the arc, and it is further clear that there is no breaking of the electric current in
the feeding of the material to be treated, as the electric current between the two
electrodes is not broken by the oscillatory movements given to the upper
electrode.
The amount of material placed in the box F being known, it is obvious that a
determined quantity of material to be treated can be brought within the influence
of the heat. incident upon the formation of the are between the opposite electrodes,
an amount can be admitted proportionate to the heat generated by the are.
As.
the material is reduced between the electrodes, the same can be separated and
provide room for more material by operating the lifting screw C and the
connecting mechanism, to raise the electrode C, which while increasing the length
of the arc between the electrodes does not break the circuit.
While the drawings have shown mechanism arranged for feeding the material
when the electrode is pulled toward the right hand, as shown in full lines Figure 2,
it is clearly obvious that another receptacle similar to that indicated by the
letter E, but reversed in position, so that its roller corresponds to the roller F,
would bear against the other side beam D', can if desired, be placed alongside of
the receptacle E and would be operated in a similar manner to that described for
the receptacle E, and would drop the material to be treated down the right hand
side of the electrode C instead of the left hand side, as is the case in the apparatus
shown in the drawing and described in the specification, and by providing two such
receptacles, the material to be treated can be dropped down both the left hand and
the right hand sides of the electrode C; and further, it will be noted that the
movements of the electrode C leave a clear passage for the dropping of the fresh
material H on to the electrode B or the fused product H' formed on top of said
electrode B.
From the above it is clear that the new material to be treated is dropped on the
lower electrode, or on the material previously smelted and located on said
electrode B, and can be brought within the influence of the arc formed between
the electrodes; consequently, as the material is introduced or fed directly within
the influence and in the path of the moving arc, the heat is fully utilized, and a
great saving is accomplished over furnaces where the material is not so introduced
or fed directly and positively within the influence of the arc, because, as previously
stated, the heat necessary for smelting is of sufficient intensity only within the
influence of the arc formed between the opposite electrodes, and the electric current
is not consumed merely in forming the arc.
I do not limit myself to the arrangement and construction shown, as the same
may be varied without departing from the spirit of my invention.
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 :-
1. In an electric arc furnace, a movable electrode, mechanism for moving said
electrode, and mechanism adapted to be operated by the movement of said
movable electrode for feeding the material to be smelted within the path of the
electric arc.
2. In an electric arc furnace, a suspended electrode, mechanism for oscillating
said electrode, and mechanism adapted to be operated by the movement of said
movable electrode for feeding the material to be smelted within the path of the
electric arc.
3. In an electric arc furnace, a movable electrode, mechanism for moving said
electrode, a receptacle in conjunction with said electrode for receiving the material
to be treated, and mechanism adapted to be operated by the movement of said
movable electrode whereby material in said receptacle is fed within the path of
the arc.
4. In an electric arc furnace, an upper electrode, a lower electrode, mechanism

page_text: for moving the upper electrode horizontally with relation to the lower electrode,
and mechanism for feeding the material to be smelted in the path of the electric
arc upon the movement of said movable electrode.
Dated this 17th day of September 1896.
JENSEN & SON,
77 Chancery Lane, London, W.C., Patent Agents.