US654463A - Electric furnace. - Google Patents

Description

, Patented luly 24, 190D;l H. LELEUX.

ELECTRIC FURNACE..

(Alplicsion med .my 7, 1899.)

3 Sheets-Shes# 2,

(No Model.)

TH: Novws Pzrzns co., Pucrournu.. WASHINGTON, n. c.

No'. 654,463. Patefed my 24, |900.

u. LELEux.

ELECTRIC FURNAGE.

(Application filed July 7, 1899.)

3 Sheets-Sheet 3,

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UNITED STATES PATENT OFFICE.

HENRI LELEUX, oE PAEis, FRANCE, AssieNoE To LA 'coMPAcNiE ELEcTEo- METALLUEGIQUE DES PEocEDEs GIN .t LELEUX, oE SAME PLACE.

ELECTRIC FU RNACE.

V SEECIFICATION forming part of Letters Patent No. 654,463, dated July 24, 1900. Application iiled .Tuly '7,1899.- Serial No. 723,117. (No model.)

To @ZZ whom it may concern:

Be it known that I, HENRI LELEUX, a citizen of France, residing at Paris, France, have invented certain new anduseful Improvements in Electric Furnaces, of which the following is a speciiication.

This invention relates to improvements in electric furnaces of the kind more especially intended for the manufacture of carbid of xo calcium, and has for its object to improve the working of the same and to increase their yield; and in order that the invention may be clearly understood I will describe the same in detail, with reference to the accompany- I5 ing drawings, in which- Figure l is a longitudinal section of a furnace constructed according to my invention. Fig. 2 is a transverse section of the same. Figs. 3 and 4 show, onva larger scale, the

zo means adopted for connecting one of the electrodes with one of the electric conductors or leads.

The improvements which I shall describe relate more especially to furnaces known as z5 resistance furnaces, comprising, on the one hand, a vertical electrode capable of a rising-and-falling movement adjustable at will and, on the other hand, a crucible or melting-pot with a fixed hearth or bed-plate 3o constituting the second electrode and serving for the return of the current. The crucible is mounted on a carriage or suspended from traveling pulleys.

The point to which my improvements relate is the construction of the vertical electrodes. In ordinary furnaces with carbons of high conductivityT the heat developed by the passage of the current or transmitted by the heat from the hearth is frequently suffi- 4e cient to raise the electrodes to a red heat and cause their rapid destruction by combustion' in the air. To overcome this objection, the upper electrode, according to my invention, is formed of one or more cores a of carbon of high electric conductivity. In the drawings I have shown, by way of example, an electrode with four cores square in section; but it will be understood that the number and the sectional form of the cores may be varied. e These cores are each surrounded by a mass l) of carbon agglomerated' by means of oil-tar.

The carbon and oil-tar are crushed together in especially-constructed mills, and the whole is coked in a muftle-furnace at a temperature not exceeding 1,0000. been su fliciently coked, the electrode is constructed by assembling in a suitable manner blocks made withthis agglomerate mass and cores of conductible carbon. l thus obtain an electrode with an increased external sur- 6o face, whereby its cooling is facilitated by the surrounding air, while the superficial material of the electrode has a comparativelylow conductivity, so as to protect the cores from the furnace heat. l thus keep the surface of the material at a temperature below that which is necessary for the combustion of the carbon, which is a great advantage, the electrode being maintained cool by the current of air entering from outside the fur- 7o nace and drawn in by the draft of the chimney c. Moreover, from the temperature of the hearth all the portions of the lower sections of the electrode acquire perceptibly the same electric conductivity, so that the current spreads over the kwhole section.

The vertical electrode is characterized by its connections with the conductors. The current enters by the upper conductor on, passl ing thence by cables n to an armature formed 8o of plates p, corresponding in number to the cores a in the electrode, and which may be raised and lowered by a iiy-wheel c and chain and pulleys. Figs. 3 and l indicate the manner in which the plates p are connected to the 8 5 carbons a. Over the two internal faces of each of the carbons a there is applied a con-l tinuous elastic pad formed by thin plates q of red copper, silvered or not. The plates p are applied to one side of each pad and kept in 9o position by means of wedges r and keys s with screw-heads having nutstthereon. By tightening up the nuts t thev simultaneous locking of the two plates p on the corresponding carbon a is thus secured. A similar arrangement is employed to obtain perfect contact Abetween the carbons a and that portion of the pad q over the faces of which there are no plates p. Bolts u, passing through the two carbons a and the two plates p, insure a good Ioo connection between the electrode on the one hand and the armature formed by the plates When the same has 55 v 2 ese/ies p on the other hand. This arrangement for connecting the parts togetherhas the advantage of preventing any disarrangement ofthe parts which might arise from unequal eXpansion of the carbon and the metal forming the leads. The lower electrode is formed bythe bed or hearth of the furnace, which consists of carbon blocks e e and t, the blocks of carbon e e being arranged in two layers-upper and lowerwseparated by a layer of insulating material j', composed of refractory noneonducting concrete, the object being to facilitate the flow of the product-for example7 carbid of calcium-bylocalizing and concentrating the caloriiic action of the current opposite the dischargeholes (l, thus maintaining at this point a higher temperature than over the rest of the furnace-hearth to facilitate iiow of the carbid. The two superposod parts e of the bed-plate are connected by blocks of carbon g of relatively-redoced section and situated immediately adjacent to the outlet or discharge holes d. i The passage of the electric current through these carbons g of relatively-reduced section and situated iinlnediately adjacent to the outlet or discharge holes d maintains at this part a higher temperature than over the rest of the bed of the furnace,thus facilitating the iiow ofthe carbid.

The furnace-bed is supported on a carriage 7L, which is made separate from the bed and merely acts as a support. The furnacebed is incloscd in a casing, preferably of metal i,

provided with perforations for dividing the gases which form in the crueible into thin streams, which are collected in the channels 7a, formed in the walls of the furnace communicating with the draftchimney c, said channels 7,; being separated from the furnace by a perforated partition 7c'.

The connection for connecting the bed of the furnace with the other pole of the source of electricity is obtained automatically by merely placing the carriage with the bed-plate thereon in position.

lVhat I claim as my invention isn An electric furnace provided with a verti cally-arranged electrode formed by one or more cores of carbon of high conductivity each core being surrounded by an agglomerated mass of carbon having a less high conductivity, each of these cores having its two inner faces provided with an elastic pad in order to provide a large surface of contact between the electrode and the plates connected to the leads and said plates being Secured against the pad by means of wedges and keys in order to obtain a permanent tightening what` ever may be the temperature of the electrodo.

ln testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

HENRI LELE TX. Witnesses:

EDWARD i?. MACLEAN, ALFRED FnnY.

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