Patent US3594486A successfully refreshed from Google Patents.
US3594486A
Expired / Lapsed
US
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Process and equipment for operating electric arc furnaces
Assignee: Heppenstall Co
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Filing: 1969-09-25
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Granted: 1971-07-20
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Expires: 1989-09-25
Abstract
Abstract A process and apparatus are provided for operating three-phase electric arc furnaces by maintaining equal impedance in all of the three electrode circuits. This may be accomplished by adjusting the relative sag of the circuit wires.
Inventors
- 👤 Manfred Jellinghaus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:08
CPC Classifications
H; H05; H05B; H05B7/00; H05B7/005
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
64 words
A process for operating three-phase electric arc furnaces having three electrodes, comprising the steps of connecting the three electrodes to a power source through three independent lines each with a cable having a normal sag therein, monitoring the impedance in each line and adjusting the relative sag in said cables as their impedance changes to maintain equal impedance in all of the electrode circuits.
Claim 2
Dependent Claim
64 words
A process for operating three-phase electric arc furnaces having three electrodes, comprising the steps of connecting the three electrodes to a power source through three independent lines each with a cable having a normal sag therein, monitoring the impedance in each line and adjusting the relative sag in said cables as their impedance changes to maintain equal impedance in all of the electrode circuits.
Claim 3
Dependent Claim
70 words
A process as claimed in claim 1 wherein equal impedance is achieved by arranging three electrodes, one for each phase, in a triangle with two of said electrodes equidistant from a common power source, monitoring the impedance of all three lines and automatically changing the relative sag of the cables connecting said two electrodes and the power source with respect to cables connecting the third electrode and said power source.
Claim 4
Independent Claim
72 words
An apparatus for operating three-phase electric arc furnaces having three electrodes and a transformer spaced therefrom comprising cable connections between said transformer and each of said electrodes having a sag therein and forming with said electrodes three separate electrode circuits, means for measuring the impedance in each said electrode circuit and impedance-adjusting means acting on the cable sag in each circuit to alter said cable sag and thereby maintain equal impedance therein.
Claim 5
Independent Claim
72 words
An apparatus for operating three-phase electric arc furnaces having three electrodes and a transformer spaced therefrom comprising cable connections between said transformer and each of said electrodes having a sag therein and forming with said electrodes three separate electrode circuits, means for measuring the impedance in each said electrode circuit and impedance-adjusting means acting on the cable sag in each circuit to alter said cable sag and thereby maintain equal impedance therein.
Claim 6
Independent Claim
103 words
An apparatus for operating three-phase electric arc furnaces having three electrodes and a transformer spaced therefrom comprising connections between said transformer and each of said electrodes forming with said electrodes, three separate electrode circuits, means for measuring the impedance in each said electrode circuit, said electrodes being carried on electrode arms overhanging the furnace and the electrode circuit including an elongated pipe carried on lift means responsive to impedance change mounted on the support arms and carrying a current wire connected to the transformer, said circuit wire having a sag therein adjusted by raising and lowering said elongated pipes relative to one another.
Claim 7
Independent Claim
103 words
An apparatus for operating three-phase electric arc furnaces having three electrodes and a transformer spaced therefrom comprising connections between said transformer and each of said electrodes forming with said electrodes, three separate electrode circuits, means for measuring the impedance in each said electrode circuit, said electrodes being carried on electrode arms overhanging the furnace and the electrode circuit including an elongated pipe carried on lift means responsive to impedance change mounted on the support arms and carrying a current wire connected to the transformer, said circuit wire having a sag therein adjusted by raising and lowering said elongated pipes relative to one another.
Claim 8
Independent Claim
88 words
An apparatus for operating three-phase electric arc furnaces haVing three electrodes and a transformer spaced therefrom comprising connections between said transformer and each of said electrodes forming with said electrodes, three separate electrode circuits, means for measuring the impedance in each said electrode circuit and impedance-adjusting means acting on each circuit to alter said circuits to maintain equal impedance therein, said impedance measuring means including means for measuring the effective length of each electrode and means for controlling the impedance adjusting means relative to the effective electrode length.
Claim 9
Independent Claim
88 words
An apparatus for operating three-phase electric arc furnaces haVing three electrodes and a transformer spaced therefrom comprising connections between said transformer and each of said electrodes forming with said electrodes, three separate electrode circuits, means for measuring the impedance in each said electrode circuit and impedance-adjusting means acting on each circuit to alter said circuits to maintain equal impedance therein, said impedance measuring means including means for measuring the effective length of each electrode and means for controlling the impedance adjusting means relative to the effective electrode length.
References Cited (Backward Citations)
US3078325A
Cited
US3156754A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |