US575829A - Chusetts - Google Patents

Description

(No Model J. JOYCE & J. A. DEUTHER.

ELECTRIC FURNACE.

Pate nted Jan. 26, 1897.

UNITED STATES PATENT OFFICE.

JOHN JOYCE, OF ANDOVER, AND JAMES A. DEUTHER, OF BOSTON, MASSA- CHUSETTS.

ELECTRIC FURNACE.

SPECIFICATION forming part of Letters Patent No. 575,829, dated January 26, 1897.

Application filed October 12,1896. Serial No. 608,595. (No model.)

{lb wZZ whom it may concern.-

Be it known that We, JOHN JOYCE, of Andover, county of Essex, and JAMES A. DEU- THER, of Boston, county of Suffolk, State of Massachusetts, have invented certain new and useful Improvements in Electric Furnaces and we hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled 1c in the art to which it appertains to make and use the same.

Our invention relates to improvements in electric furnaces for the manufacture of calcium carbid and for the reduction of refrac- I5 tory and other metallic compounds; and its main object is to facilitate the bringing of the material to be treated directly within the illfluence of the electric are formed between two separated electrodes, and through which the electric current passes.

In electric furnaces the heat generated between two separated electrodes is sufficiently intense within the field of the are formed between said electrodes for reduction, while out- 2 5 side of 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 brought directly within the influence of the arc, and, further, when such material has been properly affected by the heat incident upon the formation of v the are new material should be supplied for treatment, and no time should be lost in in troducing the proper amount of new material required.

To illustrate, in the process of making calcium carbid in electric furnaces this compound, when pure, is composed of metallic calcium and carbon, the metallic calcium required being obtained, preferably, from oXid of calcium and the carbon from coke. Now

in order to bring about the chemical formation of calcium carbid 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 the arc is not high enough to 4 produce the product required. This lower temperature, however, at a few inches from the seat of said are is sufficient to form combustion of the carbon mixed with oxid of calcium and properly volatilize the lime, and be- 5 5 fore this so-called burned-out mixture of maid of calcium can again be utilized or properly treated by the arc to produce calcium carbid additional carbon must be added to take the place of the carbon burned out. Conse- 6o quently to avoid the action of burning out of 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 are, so as to be acted upon in a comparatively short time.

As is well known, in the practical application of the heat incident upon the formation of the electric arc in the treatment of certain materials, especially refractory compounds in electric furnaces, difficulty is experienced in bringing the materials or compounds to be so treated in said electric furnaces directly and at stated and determined periods of time within the sphere of the influence of the electric arc to be properly acted upon by said electric arc. The sphere of influence of the electric arc in the reduction of certain alkaline earths may be defined as where the heat consequent upon the formation of the electric are is of sufficiently high temperature to bring about a reduction of the alkaline earths or other compounds under treatment.

Now it is the purpose and object of our invention to facilitate the bringing of the com- 8 5 pounds under treatment in the electric furnace within the sphere of influence of the arc. and to bring said compounds in determined quantities at determined periods of time, and to maintain and keep said compounds in deo tcrmined quantities for determined periods of time within the influence of the electric are formed between two separated electrodes.

In the accompanying drawings, which illustrate a construction embodying our invention, Figure l is a vertical crosssection through the electric furnace and showing the opposite electrodes in full lines. Fig. 2 is a similar View, but showing in full lines the lower electrode moved toward the right and also showing in dotted lines the lower electrode moved toward the left. ll ig. 3 is a detail plan view, hereinafter described, looking down from the line X X, Fig. 1.

The electric furnace A is constructed of fireproof material A, and located in the bot tom of the furnace is the electrode 13, of conducting material and connected to one pole of an electric generator by a suitable wire B, and preferably, but not necessarily, of larger diameter than the upper electrode 0, which is connected to the other pole of the electric generator by a suitable wire The upper electrode 0 is suspended above the electrode 13 by means of a rod C which is provided with two forked arms C secured by suitable nuts C to the upper part of the electrode C. The rod extends upwardly through the cross-beam 1), supported by the side beams l), and the upper end ot the rod C projects through the cross-bar C, and suitable nuts C hold said red C" connected to the cross-bar Through the opposite end of the cross-bar C the lifting-screw C working in the nut (i is arranged, and its lower end works in the socket C on said cross-beam D, and by means of said lifting-screw C the upper electrode C can be raised and lowered by the mechanism above described.

To the top of the electrode 0 is :tirmly secured a rectangular receptacle E, provided on opposite sides of the electrode (7 with the ports 1*) and \Vithin the receptacle E are two movable bottomless boxes F and G, connected together by the crossbar ll, and in the normal position of the parts said boxes are in the posi tion shown in llig. 1, between the ports 111 and 1?.

The bottom electrode 13 is mounted on a suitable casting 13*, provided with rollers 1.3 to facilitate the movement of said lower electrode along the bottom plate A Said cast-- ing 13 is provided on one side with a socket 13", in which is held a ball 13 on the inner end of the shaft 13, having a worm-gear through.- out the greater part of its length, and which extends out through the side wall A and the side beam D and at its outer end is provided with a suitable handle 11 Firmly secured in the side beam D is a nut Bflin which the wormgcar on the shaft 13'works. At about the center of the shaft 13 there is located a ver-- tical rod J, having a sleeve J Slll'lt)ll11tllllg the shaft 1.1, and a pin J projects through said sleeve into the groove of the worm-gear, so that in the operation of said shalt 13 the movement thereof operates the vertical rod J. The upper end of said rod .1 extends through an eye J on the end of the rod K, which passes through the receptacle E and is connected at its outer end with the box G.

It is obvious that by turning the handle 13" the lower electrode 13 can be moved toward the right, as shown in Fig. 2, and in the same movement the rod .1 acts on the rod K and moves the boxes l and tlto the positions shown, so that the mater l contained in the box G passes from said box G, through the port down onto the top of thebottom electrode ll. lly turningthe lmndlel thelowcr electrode 13 can be moved to the position shown in dotted lines,l ig. 9,and in said movement the rod J, acting on the rod l\,will move the boxes F and G so that the box 11'' will register with the port it, as shown in dotted lines, Fig. 2, and the material will drop down onto the top of the lower electrode 13.

The amount of materialplaced in tlIOlMJXOh F and G being known, it is obvious that a determined amount of material to be treated can be brought within the influence ol. the heat incident upon the formation of the arc between the opposite electrodes, and an amount can thus be added proport ional tothe heat generated by the are.

As the material is red uced between the electrodes the same may be separated, and thus provide room for more material by operating the lifting-screw U and connecting mechanism to raise the electrode 0, which, while increasing the length of the are between the electrodes, does not break the circuit, as the reduced material is a coi'iductor and forms then a part oi. the lower electrode.

From the above it clear that the new material A to be treated is dropped onto the lower electrode or onto the material pre viously smeltcd. Consequently as the electrode is moved toward :its original position the material is brought directly within the influence and in the path of the electric arc, the heat is fully utilized, and a great saving is accomplished over l'nrnaces where the material is not so directly and positively brtnlght within the influence of the are, because, as previously stated, the heat necessary for smelting is otsut'ticient intensity only within the influence of the are formed between the opposite electrodes, and the current is not consumed merely in ft'irming the are.

The movement of the lower electrode 1. it will be understood, does not break the el rcuit but the are moves correspondingly withthe movement 01: the lower electrode, as it well known that the electric are between two electrodes will follow the path of least resistance, and consequently will. be formed. in those portions of the two electrodes which are nearest to each other.

lfhen the electrode 13 is in. the position shown in full lines, Fig. 2, to receive new'ma terial on the right side, the material. on the other half of the electrode is within the in tluencc of the arc, and as the electrmlo i is moved toward the left to receive the material on the left side of the electrode the nnitcrial which has been led on. the right side of the electrode 13 is being acted upon by the electric arc. Consequently it is clear that while the electrode 13 is receiving new material the electric arc is acting on the material pre- IIO viously received, so that the material is brought directly in the path of the moving arc, and consequently within the direct influence of the heat incident upon the formation of said are.

Suitable openings L are provided in the bottom plate A through which the raw material not acted upon by the arc may be withdrawn.

lVe do not limit ourselves to the arrange ment and construction shown, as the same may be varied without departing from the spirit of our invention.

Having thus ascertained the nature of our invention, what we claim as new, and desire to secure by Letters Patent of the United States, 1,

1. In an electric-arc furnace, an upper electrode, a lower electrode, a mechanism for moving said electrode from its normal position to expose the same to receive the material to be treated, a mechanism for returning said lower electrode to its normal position, and a feed mechanism for feeding the material to be treated onto said lower electrode during the interval between the movements of the lower electrode from and to its normal position.

2. In an electric-arc furnace, an upper electrode, a lower electrode, mechanism for movin g said lower electrode from its normal position to expose the same to receive the material to be treated, and a feed mechanism operated by the said movement of said lower electrode for feeding the material to be treated onto said lower electrode.

3. In an electric-arc furnace, an upper electrode, a lower electrode, mechanism for moving said lower electrode from its normal posi tion to expose the same to receive the material to be treated, and an intermittent feed mechanism connected to the upper electrode and adapted to be operated by the said movement of the lower electrode to intermittently feed the material to be treated onto said lower electrode.

4:. In an electric-arc furnace, an upper electrode, a lower electrode, mechanism for varyin g the distance between said electrodes, mechanism for moving said lower electrode from its normal position to expose the same to receive the material to be treated, and a feed mechanism connected to said upper electrode and adapted to be operated by the movement of the said lower electrode to intermittently feed the material to be treated onto said lower electrode.

In testimony whereof we have signed our names to this specification, in the presence of two subscribing witnesses, on this 2d day of October, A. D. 1896.

JOHN JOYCE. JAMES A. DEUTHER.

\Vitnesses:

A. L. MEssER, A. E. DOANE.

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