Industrial electric heating furnaces – Arc furnace device – Electrode support
Patent
1990-09-07
1993-04-06
Reynolds, Bruce A.
Industrial electric heating furnaces
Arc furnace device
Electrode support
373 95, 373 96, 373100, 373101, 373 52, H05B 710
Patent
active
052009742
DESCRIPTION:
BRIEF SUMMARY
The electrodes of arc furnaces for steel production are held by carrier arms which at the end have an electrode-clamping device and which are themselves held on supporting columns allowing vertical adjustment. Cooling-water conveying devices are provided for cooling the electrode holder and the arm itself. For supplying current to the electrodes, the carrier arms mostly used in practice have high-current lines provided separately on the carrier arms. Since these involve a considerable outlay in production and maintenance terms, it has also been proposed to produce the entire carrier arm from copper and make it current-carrying (U.S. Pat. No. -A-2,494,775). The carrier arm is made hollow and closed off at the front end by means of a flanged plate which serves for flanged connection to the electrode-clamping device. Some of the current fed to the clamping device is also conveyed via the flanged connection. The cooling liquid is fed to the clamping device from the cooling-liquid cavity provided inside the carrier arm via outer pipes and passed the flanged connection. It is not yet known whether such an electrode carrier arm is successful in practice; at least where larger furnaces are concerned, the adverse ratio between the strength and weight of copper as the material of the carrier arm seems to be highly unfavourable.
This defect is remedied by another known construction (EP-A-0,184,140), in which the carrier arm consisting of steel is plated on the outside with copper or aluminium. This involves a very high outlay. At the end, the arm, including its cooling-liquid cavity, is limited by a flanged plate which serves for flanged connection to a contact jaw of the clamping device, it also being intended for the current to be supplied via this flanged connection. In practice, however, this construction is designed with a separate current connection, bypassing the flanged connection, from the copper plating of the carrier arm to the contact jaw, and it can be concluded from this that the current supply via the flanged connection presents problems, even when copper is used; in particular, it is not possible to guarantee an absolutely uniform large-surface transition contact in the flanged connection, and therefore local overheating can occur and quickly lead to destruction.
In yet another known electrode carrier arm (FR-A-1,336,823), therefore, the carrier arm current-carrying as a whole and produced from aluminium is not connected to the electrode-clamping device via a flanged connection, but the end plate limiting the carrier arm at the end is welded to the sectional parts forming the clamping device. This avoids the problems of contact-current transfer in the region of a flanged connection. A disadvantage, however, is that the clamping device cannot be released from the carrier arm. In the known instance, this may be acceptable because the power and therefore also the generation of heat and maintenance requirement are low.
The object on which the invention is based is to provide an electrode carrier arm, which involves a lower outlay than a steel arm plated with copper or aluminium and which allows a releasable current-carrying flanged connection between the arm part and the electrode-clamping device.
The solution according to the invention lies in an electrode carrier arm for an electric arc furnace comprising a current-carrying arm part made from a material of high conductivity and having an internal cavity for the circulation of cooling liquid. The current-carrying electrode clamping device is made from a material of high conductivity and has an interior cavity for the circulation of cooling liquid. A current-carrying flanged connection is between the cavity of the arm part and the cavity of the clamping device. The flanged connection includes orifices for the passage of cooling water between the cavity of the arm part and the cavity of the clamping device.
Producing the arm from light metal makes it possible to do without a steel case, whilst at the same time ensuring sufficient stability.
As used herein,
REFERENCES:
patent: 2133329 (1938-10-01), Moore et al.
patent: 2148834 (1939-02-01), Payne
patent: 2386260 (1945-10-01), Payne
patent: 2494775 (1950-01-01), Moore
patent: 2538603 (1951-01-01), Thys
patent: 2623080 (1952-12-01), Young
patent: 3433878 (1969-03-01), Sundberg et al.
patent: 3444305 (1969-05-01), Turner
patent: 3602624 (1971-08-01), Turner
patent: 3686421 (1972-08-01), Wunsche et al.
patent: 4182927 (1980-01-01), Phillips
patent: 4385391 (1983-05-01), Hillers et al.
patent: 4670884 (1987-06-01), Letizia et al.
patent: 4682341 (1987-07-01), Ehle et al.
Kark Uwe
Klein Karl-Heinz
Badische Stahl Engineering GmbH
Hoang Tu
Reynolds Bruce A.
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