US1679284A

US1679284A - Process for production of self-baking electrodes

Info

Publication number: US1679284A
Application number: US712A
Authority: US
Inventors: Westly Jens
Original assignee: DET NORSKE AG FOR ELEKTROKEMIS
Current assignee: DET NORSKE AG FOR ELEKTROKEMIS; DET NORSKE AG FOR ELEKTROKEMISK INDUSTRI OF NORWAY
Priority date: 1924-01-17
Filing date: 1925-01-05
Publication date: 1928-07-31
Anticipated expiration: 1945-07-31

Description

July 31, 192s. '13579284 D J. WESTLY PROCESSFOR PRODUCTION OF SELF BAKING 'LECTRODES Filed Jan. 5, 1925 gwen/tot 61H01 u e 14 ing Patented July 31, 1928.

UNITED STATES PATENT OFFICE.'

.TENS WESTLY, F CHRISTIANSAND, NORWAY., ASSIGNOR TO D'ET NORSXE AKTIEHEL- Sm FOB ELEKTROKEMISK INDUSTRI OIF NORWAY, 0F OSLO, NORWAY.

:PROCESS FOB PRODUCTION 0F SELF-BARING ELECTBODES.

appumian ma January 5, 1925, serial No. 712, and in Norway January 17, 1924.

`The present application relates to selfbakelectrodes provided with metallic man.- tes, that is electrodes which are baked 1n t e object of the invention is a process which -makes 1t possible to avoid introductionv of detrimental materlal from the mantle into the furnace. Such selfbaking electrodes are 'described in U. S. Patentv No. 1,440,724

wherein is stated that one of the functions of the mantle is to transmit the current to the electrode. For that purpose it is often provided'with internal ribs or extensions pro- 'ccting into the electrode mass and facilitatmg the paage of the current, as these ribs maintain an excellent contact with the mass. Generally both the mantle and the ribs are made of iron and the ribs form a part of the plate from which the mantle is made.

The iron melts during the process and enters into the product of the furnace. In special cases'the mantle may also be made of. other metals, as for instance copper or aluminium. These metals, however, have the drawback that their meltin e point is considerably lower than that of 1ron (respectively 150 G. and 660 0.). This drawback is especially noticeable with aluminium, whose melting point is so low that the electrode at 'that temperature is not yet so well baked that it has even approximately reached'its normal electric conductivity. If both mantle and ribs are made of aluminium there will be a greater loss of voltave in the electrode than that normally found when employing iron. I have, however, found that the loss of voltage may be reduced to a considerable extent by making the ribs of comparatively f great thlckness. They will then allow the electric currentto pass through them without being heated to' any considerable extent and they will not melt until the surroundingr mass-has reached a temperature corresponding to their melting point.

The ribs may be arran ed horizontally or verticall or at any ang e' with horizontal plane. urther they may be partly horizontal or vertical and artly inclined. A s al advantage is obtained if the internal ribs slope downwardly into the electrode mass.

If the metal of the ribs melts it will then not run out of the electrode, but will remain in a pocket in the electrode ma and maintain the connection with the non-molten part furnace in which they are used and they of the mantle. In this .way it is possible to eilect passage of the current from metal to electrode at temperatures ranging above the Fig. 2 is a cross section of the same electrode the numerals indicating the same parts as in Fig. 1. A

Another modification of my invention con. sists in reducing the size of the ribs So much that the amount of metal which passes into the furnace on account of the ribs is unimportant as compared with the amount of the product and in such cases the ribs may be made of iron or other material detrimental to the product even if this cannot be permitted -in the furnace in larger amounts. This especially applies to furnaces for, the production of aluminium. The mantle which is allowed to pass into the bath should of course in such cases not be made of iron,

but of a non-detrimental metal such as aluminium and care should then be takento su ply the electric current to the ribs in a sa e manner; for instance by means of a clamping arrangement attached to the mant e or to external prolongations of the ribs as described and claimed/in my copending application Serial No. 711.

It is of course advisable in the present case to reduce the si'ze of the iron ribs to the minimum possible in order to introduce the least possible amount of the detrimental metal into the furnace. This may be effected by placing the electrode Aholder as farv as possible on baked electrode carbon whereby as much as possible of the current will ass directly over to the electrode under the ho der without passing through the ribs. In prac- -1ron melts at about 850 C., that is about n0 200 C. higher than pure aluminium. The alloy is therefore` better adapted for use as rib material than aluminium. It is, however, dificult to roll for Which reason it will be preferable to make the ribs by casting.

What I claim'as new and desire to secure by Letters Patent of the United States is:

1. A selfbaking electrode having a mantle of one composition, non-detrimental to the processin connection with which the electrode is being used, and internally projccting ribs of another composition attached to said mantle.

2. A selfbaking electrode having a. mantle of one composition, non-detrimental to the proce-ss in connection with which the electrode is being used, and internal ribs composed of a comparatively ditlicultly fusible metal and attached to said mantle. v

3. A selfbaking electrode having a mantle of one composition, non-'detrimental to the process in connection with which the electrode is being used, and internal ribs composed of a comparatively dicultly fusible metal attached to said mantle in combination with an electrode holder attached to a baked part of the'electrode..

4. A selfbaking electrode having an aluminum mantle and internal ribs composed of a comparatively difficulty fusible metal attached thereto.

5. A selfbaking electrode having an aluminum mantle and internal ribs of diflicultly fusible metal attached thereto, said ribs being of such small size that they Will not introduce a detrimental amount of such metal into the furnace product.

6. A Selfbaking electrode having an aluminum mantle and internal aluminum ribs attached thereto, said ribs being of such dimensions as to avoid' any considerable heatl ing due to the passage of electric current.

A se-lfbaling electrode having an aluminum mantle and internal aluminum ribs attached thereto, said ribs being of such dimensions as to avoid any considerable heating by the electric current passing therethrough, said ribs being disposed at an angle With the horizontal plane.

8. A selfbaking electrode having an aluminum mantle and internal aluminum ribs att-ached thereto, said ribs being of such dimensions as to avoid any considerable heating by the electric current passing therethrough, said ribs sloping downwardly into the elect-rode.

9. A self-baking electrode having an aluminum mantle, and internally projecting ribs of another composition attached to said mantle.

J EN S WESTLY.