US4254298A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct current smelting furnace
Assignee: Elkem ASA
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Filing: 1978-11-09
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Granted: 1981-03-03
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Expires: 1998-11-09
Abstract
Abstract A direct current smelting furnace is disclosed. The anode and cathode are series connected electrodes, both of which are immersed in the furnace charge. A plurality of pairs of electrodes is preferably employed.
Inventors
- 👤 Eivind C. K. Svendsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:33
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/60; H05B3/0019; H05B3/0023
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
130 words
In an electric smelting furnace comprising a furnace pot adapted to contain a charge to be smelted, the improvement comprising: (a) at least two pairs of electrodes arranged in said furnace from the top thereof; (b) a rectifier for supplying direct electric current to said electrodes; (c) each pair of electrodes being connected in series with the rectifier output wherein one electrode within each pair acts as a cathode and the other acts as an anode; and (d) switching means, disposed between each said pair of electrodes and said rectifier output, capable of reversing the polarity of each said pair of electrodes, said switching means also being capable of switching the polarity of each said pair of electrodes independently of the switching of at least one other pair of electrodes.
Claim 2
Dependent Claim
130 words
In an electric smelting furnace comprising a furnace pot adapted to contain a charge to be smelted, the improvement comprising: (a) at least two pairs of electrodes arranged in said furnace from the top thereof; (b) a rectifier for supplying direct electric current to said electrodes; (c) each pair of electrodes being connected in series with the rectifier output wherein one electrode within each pair acts as a cathode and the other acts as an anode; and (d) switching means, disposed between each said pair of electrodes and said rectifier output, capable of reversing the polarity of each said pair of electrodes, said switching means also being capable of switching the polarity of each said pair of electrodes independently of the switching of at least one other pair of electrodes.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-02 | 1984-09-01 | 1985-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-02 | 1988-09-01 | 1989-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-02 | 1992-09-01 | 1993-03-03 | $7700.00 | Window Closed / Lapsed |