US4038483A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means for direct current arc furnaces
Assignee: ABB Norden Holding AB
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Filing: 1976-01-07
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Granted: 1977-07-26
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Expires: 1996-01-07
Abstract
Abstract A DC electric arc furnace having laterally offset hearth and arcing electrodes, has the arcing electric power for one of the electrodes carried by a conductor arranged with respect to the furnace hearth to provide an electric field within the furnace and which bucks the field created by the offset electrodes so that the arc formed within the furnace is vertically oriented.
Inventors
- 👤 Sven Einar Stenkvist
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:43
CPC Classifications
H; H05; H05B; H05B7/00; H05B7/02; H05B7/005
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
155 words
A DC electric arc furnace comprising a furnace enclosure having a hearth for containing a melt, said hearth having a contact electrode for the melt, an arcing electrode positioned above the melt for forming an arc with the melt when placed in circuit therewith via said electrode, said arcing and contact electrodes being relatively offset in a horizontal direction so that the arc is normally angularly deflected with respect to a vertical direction, and means for applying a magnetic field to the arc so as to control its arcing direction, said furnace having a DC power source and means for electrically connecting said electrodes in series with said source to form through said melt, an electric power circuit powered by said source, said means being formed by said power circuit including at least one electric conductor positioned to form said magnetic field and which is in series connection with the balance of said power circuit.
Claim 2
Dependent Claim
155 words
A DC electric arc furnace comprising a furnace enclosure having a hearth for containing a melt, said hearth having a contact electrode for the melt, an arcing electrode positioned above the melt for forming an arc with the melt when placed in circuit therewith via said electrode, said arcing and contact electrodes being relatively offset in a horizontal direction so that the arc is normally angularly deflected with respect to a vertical direction, and means for applying a magnetic field to the arc so as to control its arcing direction, said furnace having a DC power source and means for electrically connecting said electrodes in series with said source to form through said melt, an electric power circuit powered by said source, said means being formed by said power circuit including at least one electric conductor positioned to form said magnetic field and which is in series connection with the balance of said power circuit.
Claim 3
Dependent Claim
21 words
The furnace of claim 1 in which said electric conductor extends below said hearth and the hearth is of nonmagnetic construction.
Claim 4
Dependent Claim
24 words
The furnace of claim 1 in which said electric conductor extends around the side wall of said enclosure and said side wall is non-magnetic.
Claim 5
Dependent Claim
38 words
The furnace of claim 2 in which said conductor is formed by two parallel conductors which extend under said hearth and then separately loop in opposite directions around the side of said enclosure, said side wall being non-magnetic.
Claim 6
Dependent Claim
17 words
The furnace of claim 4 in which said conductors loop around an upper portion of said side.
Claim 7
Dependent Claim
18 words
The furnace of claim 2 in which said electric conductor is formed into at least one coil convolution.
Claim 8
Dependent Claim
16 words
The furnace of claim 2 in which said electric conductor is provided with an iron core.
Claim 9
Dependent Claim
31 words
The furnace of claim 2 having multipole electro-magnets positioned below said hearth with their poles arranged to cause said arc to rotate when said electro-magnets are supplied with low frequency AC.
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) | 1980-07-25 | 1981-01-24 | 1981-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-25 | 1985-01-24 | 1985-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-25 | 1989-01-24 | 1989-07-26 | $7700.00 | Window Closed / Lapsed |