US785832A

US785832A - Electrode for electric furnaces.

Info

Publication number: US785832A
Application number: US17760703A
Authority: US
Inventors: Edgar F Price; George E Cox; James G Marshall
Original assignee: Union Carbide Corp
Current assignee: Union Carbide Corp
Priority date: 1903-10-19
Filing date: 1903-10-19
Publication date: 1905-03-28
Anticipated expiration: 1922-03-28

Description

No. 785,832. APATENTED MAR. 28, 1905. E. P. PRICE, G. E. COX & J. G. MARSHALL.

ELECTRODE FOR ELECTRIC FURNACES.

APPLICATION FILED OOT.19, 1903.

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TVz'Znessea No. 785,832. PATENTED MAR. 28, 1905. E. F. PRICE, G. E. COX & J. G. MARSHALL. ELECTRODE FOR ELECTRIC FURNACES.

APPLICATION FILED OUT. 19, 1903.

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No. 785,832. Patented March 28,1905.

UNITED STATEs PATENT OFFICE.

EDGAR F. PRICE, GEORGE E. COX, AND JAMES G. MARSHALL, OF NIAG- ARA FALLS, NEW YORK, ASSIGNORS TO UNION CARBIDE COMPANY, OF NIAGARA FALLS, NEW YORK, A CORPORATION OF VIRGINIA.

ELECTRODE FOR ELECTRIC FURNACES.

SPECIFICATION i'OImiIIg P Of Letters Patent No. 785,832, dated March 28, 1905.

Application filed Oc obe 19, 1908. Serial No. 177,607.

To all wlwm it y COW/067%: trodes and to protect them from oxidation. 5

Be it known that we, EDGAR F. PRICE, The preferred means for effecting these re- GEORGE E. Cox, and JAMES G.MARsHALL,citisults is a' filling of refractory cement placed Zens of the United States, residing at Niagara between and around the rods, a support of Falls, in the county of Niagara and State of thin foraminous metal being embedded in the New York, have invented certain new and usecement. It is sometimes desirable to protect 5 5 ful Improvements in Electrodes for Electric one or more of the front rods of each elec- Furnaces, of which the following is a speeititrode, which are more exposed to air, by coatcation. ing the rod with tar and pushing on it a closely- IO This invention especially relates to the elecfitting iron sleeve, the upper end of which trodes which are used in electric furnaces for may be screwed in to a socket in the electrode 60 the production of calcium car-bid. These elecholder. trodes usually consist of a series of carbon The invention will be readily understood rods secured at their upper ends in an iron by reference to the accompanying drawings,

5 head which constitutes the terminal of the in which electrode. It has been found advantageous Figure 1 is a vertical transverse section 5 to use artificial graphite rods in these carbidthrough a pair of electrodes supported in furnaces in place of the usual carbon rods on the hood of a calcium carbid furnace, the account of the high electrical conductivity, section being taken on the line I I of Fig. 2.

uniform composition, and durability of the Fig. 2 is a horizontal section through the top graphite. This graphite, however, presents plate of the hood, taken on the line ll 11 of 7 the disadvantage that it unduly transmits heat Fig. 1. Fig. 3 is a vertical longitudinal seefrom the zone of reaction upward to the metion through one of the electrodeholders, tallic holder. showing a metal sheath in section upon one 5 One of the features of this invention an of the electrode-rods. Fig. 4. is a side elevaelectrode-holder having a water-chamber and tion of an electrode, partly in section to show 75 sockets for each of the graphite rods which the filling of refractory cement and the supare movably secured in the holder and proport of foraminous metal; and Fig. 5 is a horiject into the water-chamber, the water servzontal section through the electrode on the 3 ing to reduce the temperature of the metal line V V of Fig. 4.

parts. This water-cooled holder is prefer- The electrode-holder consists of a head I, of ably employed in connection with a hood havcast-iron, having a perforated lug 2, which ing a Water-cooled top, the top having openserves as a terminal and support for the elecings in which the holders are adjustably artrode. \Vithin the holder is a waterchamber ranged. 3, having supply and discharge pipes a A The high specific electrical conductivity of longitudinal depending battle 6 extends from 8 5 graphite permits the use of electrode-rods of the top nearly to the bottom of the watermaterially smaller cross-section than that of i chamber. A number of threaded openings 7 the ordinary carbon rods. Graphite rods of extend through the lower wall of the head 1,

4 a thickness reduced in proportion to the inand each of these openings receives a nipple creased current density are, however, mechan- 8. An electrode-socket 9 is threaded into the 9 ically weak and Will break if merely substilower end of each nipple and projects upward tuted for the carbon electrodes of a calciumwithin the nipple, leaving an intermediate carbid furnace. Furthermore,the thin graphspace for the circulation of water. The upite rods are readily oxidized by the atmosper end of each graphite electrode-rod 10 is phere on account of the high temperature to threaded and screwed into one of these sockwhich they are raised in use. It has thereets, making good electrical contact with it. fore been found necessary to mechanically re- The length of the depending nipples makes it inforce and strengthen the graphite elecpossible to use short electrode-rods, thus dccreasing the length of the stubs which remain when the rods have been consumed as far as possible and enabling a greater percentage of the length to be utilized. The stubs may also be threaded together and used for the electrode-rods.

The well-known Horry furnace for the production of calcium carbid employs a hood which receives the electrodes and depends into the working chamber of the furnace. One of these hoods 11 is shown in section in Fig. 1 depending into the working chamber 12 of the furnace. A pair of electrodes is shown, the holder of each electrode extending through an opening 13 in the top plate 11 of the hood. The space between the electrode-holders and the top plate is filled with a luting 14c, of refractory cement. A pipe 15 for supplying the furnace charge of lime and coke opens through the top plate at the rear, and a pipe 16 for removing the waste gases leads from the top plate at the front. To assist in removing the heat from the electrode-holders, as well as to reduce the temperature of the hood itself, it has been found desirable to make the top plate 11 of cast-iron, with an internal water-chamber 17, having a supplypipe 18 and a discharge-pipe 19.

One or more of the electrode-rods may be inclosed in a closely-fitting iron sheath 20, as shown in Fig. 3. The graphite rod is preferably coated with tar before being pushed into the sleeve. Air is thus entirely excluded from the surface of the rod. The upper end of the sleeve 20 may be threaded into a counterbore 21 in thelower end of the corresponding socket 9. The electrode-rods are mechanically reinforced and strengthened and at the same time protected from oxidation by a body 22 of refractory cement of relatively high resistance, which is filled between and around the rods. This cement may consist of ordinary asbestos or furnace-cement mixed with ground bituminous coal and siloxicon. To strengthen the body of cement and prevent it from sealing otl from the rods when heated, a support 23, of thin foraminous metal, such as expanded iron, is wrapped around the rods and plastered over with the cement.

This invention makes it possible to use graphite electrodes in a calcium-carbid furnace. The greater cost of the graphite is ofl'- set by the reduction in the thickness and length of the electrode-rods. The thin rods are efficiently strengthened and protected from oxidation by the reinforcing-body of cement. The water-cooled holders and electrode-sockets prevent the metal parts from burning out, and the long socket-nipples decrease the stub waste of the electrodes. The electrodes and holders will be found useful in electric furnaces for other purposes than the production of calcium carbid.

lNe claim- 1. An electric furnace having an opening,

teases an electrode having a holder in said opening, means for directly cooling said holder, and means for cooling that portion of the furnace adjacent to said opening and thereby indirectly cooling said holder, as set forth.

2. In an electric furnace, a hood having an opening, an electrode having a holder in said opening, means for directly cooling said holder, and means for cooling that portion of the hood adjacent to said opening and thereby indirectly cooling said holder, as set forth.

3. An electric furnace having an opening, an electrode having a holder passing loosely through said opening, a refractory luting around said holder, means for directly cooling said holder, and means for cooling that portion of the furnace adjacent to said opening and thereby indirectly cooling said holder, as set forth.

4. In an electric furnace having a working chamber, a hood depending into said chamber, an electrode or electrodes within the hood, electrode holders passing loosely through openings in the top of the hood, means for cooling said holders, and a refractory luting between said holders and the top of the hood, as set forth.

5. In an electric furnace having a working chamber, a hood depending into said chamber, an electrode or electrodes within said hood, each electrode comprising a plurality of graphite rods, a holder receiving said rods and passing through an opening in the top of the hood, and means for cooling said holder, as set forth.

6. In an electric furnace having a working chamber, a hood depending into said chamber and means for cooling the top of said hood; an electrode or electrodes within the hood, electrode holders passing loosely through openings in the top of the hood, means for cooling said holders, and a refractory luting hetween said holders and the top of the hood, as set forth.

7. In an electric furnace having a working chamber, a hood depending into said chamber and means for cooling the top of said hood; an electrode or electrodes within said hood, each electrode com prisi ng a plurality o l graphite rods, a holder receiving said rods and passing through an opening in the top of the hood, and means for cooling said holder, as set forth.

8. An electrode, comprising a series of carbon rods, a holder having an internally-threaded socket for each rod, and means for cooling said holder and sockets, as set forth.

9. An electrode, comprising a series of carbon rods, a holder having an in ternally-threaded socket for each rod, and a water-chainber in said holder and arranged to cool each socket, as set forth.

10. An electrode, comprising a series of carbon rods, a holder having a socket for each rod, and a baliied water-chamber in said hold or and receiving each socket, as set forth.

11. An electrode-holder, sockets for the electrodes removably secured in said holder, and a water-chamber in said holder and receiving each socket, as set forth.

12. An electrode-holder, having a waterchamber, a nipple or nipples opening into said chamber, and an electrode-socket in each nipple with a space between it and the nipple, as

. set forth.

13. An electrodeholder, having a waterchamber with a depending baflie, a nipple or nipples opening into said chamber, and an electrode-socket in each nipple with a space between it and the nipple, as set forth.

14. An electrode, comprising a series of carbon rods, a holder for said rods, and a reinforcing-body of refractory cement of relatively high resistance between said rods, as set forth.

'15. An electrode, comprising a series of carbon rods, a holder for said rods, and a reinforcing and protecting body of refractory cement of relatively high resistance between and around said rods, as set forth.

16. An electrode, comprising a series of carbon rods, a holder for said rods, a body of refractory cement between and around said rods, and a support of foraminous metal in said cement, as set forth.

17. An electrode, comprising a series of carbon rods, a holder for said rods, means for cooling said holder, and a reinforcing-body of refractory cement of relatively high resistance between said rods, as set forth.

18. An electrode, comprising a series of carbon rods, a holder for said rods, means for cooling said holder, and a reinforcing and protecting body of refractory cement of relatively high resistance between and around said rods, as set forth.

19. An electrode, comprising a series of graphite rods, a holder for said rods, means for cooling said holder, and a reinforcing and protecting body of refractory cement between and around said rods, as set forth.

20. An electrode, comprising a holder having a water-chamber, nipples opening into said chamber, a socket in each nipple with a space between it and the nipple, an electroderod depending from each socket, and a body of cement between and around the electroderods, as set forth.

21. An electrode, comprising a holder having a water-chamber, nipples opening into said chamber, a socket in each nipple with a space between it and the nipple, a graphite electrode-rod depending from each socket, and a body of cement between and around the electrode-rods, as set forth.

22. An electric furnace having an electrode projecting into the working chamber and 00111- prising one or more carbon rods, a holder for said rods, and a metal sheath closely fitting upon and protecting the projecting portion of one or more of said rods, as set forth.

23. An electrode, comprising one or more carbon rods, a holder for said rods, a metal sheath closely fitting one or more of said rods, and a carbonaceous cement between said rod and sheath, as set forth.

24. An electrode, comprising a plurality of graphite rods, and means for mechanically reinforcing the rods and protecting them from oxidation, as set forth.

25. An electrode, comprising a water-jacketed holder, a plurality of graphite rods, and means for mechanically reinforcingthe rods and protecting them from oxidation, as set forth.

26. An electrode, comprising a water-jacketed holder having depending nipples, a graphite rod secured in each nipple, and means for mechanically reinforcing the rods and protecting them from oxidation, as set forth.

27. An electrode, comprising one or more graphite rods, a holder having an internallythreaded socket for each rod, and means for cooling said holder and sockets, as set forth.

28. An electrode, comprising a series of graphite rods, a holder having an internallythreaded socket for each rod, and a waterchamber in said holder and arranged to cool each socket, as set forth.

29. An electrode, comprising a series of graphite rods, and a holder having a separate internally-threaded socket for each rod, as set forth.

30. An electrode, comprising a series of graphite rods, a holder for said rods, and a reinforcing-body of refractory cement between said rods, as set forth.

31. An electrode, comprising a series of graphite rods, a holder for said rods, and a reinforcing and protecting body of refractory cement between and around said rods, as set forth.

32. An electrode, comprising a series of graphite rods, a holder for said rods, a body of refractory cement between and around said rods, and a support of foraminous metal in said cement, as set forth.

In testimony whereof we affix our signatures in presence of two witnesses.

EDGAR F. PRICE. GEORGE E. COX. JAMES G. MARSHALL. l Vitnesses:

CnAnLes E. BILLINGS, EDW; J. SCHNEIDER.