Patent US4147887A successfully refreshed from Google Patents.
US4147887A
Expired / Lapsed
US
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Electric smelting furnace
Assignee: IHI Corp
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Filing: 1977-07-20
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Granted: 1979-04-03
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Expires: 1997-07-20
Abstract
Abstract An electric smelting furnace in which a hollow electrode with the wall thickness depending upon the depth of current penetration is disposed vertically within the furnace and spaced by a desirable distance from the furnace bottom, and the top of the hollow electrode is connected to a duct for discharging the furnace off-gases and charging the raw materials into the furnace after they are preheated by the furnace off-bases in the duct and prereduced in the hollow electrode.
Inventors
- 👤 Shozo Yasukawa
- 👤 Kenji Matsuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:22
CPC Classifications
H; H05; H05B; H05B7/00; H05B7/02; H05B7/06; H05B7/08; H05B7/085; H05B7/09; H05B7/144; Y; Y02; Y02P; Y02P10/00; Y02P10/25
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
95 words
An electric smelting furnace having a vertically positioned hollow electrode therein, the lower end of the electrode being spaced a predetermined distance from the furnace bottom, the wall thickness of the electrode depending upon the depth of current penetration into the electrode as determined by the equation: δ ≈ 5030 √ ρ/μf (cm) ρ:Specific resistance of the electrode (Ω-cm) μ:Specific permeability of the electrode f:Frequency, cycles per second, and conduit means for discharging furnace off-gases and for charging raw materials into the furnace through said hollow electrode, said gases serving to pre-heat the raw materials.
Claim 2
Dependent Claim
95 words
An electric smelting furnace having a vertically positioned hollow electrode therein, the lower end of the electrode being spaced a predetermined distance from the furnace bottom, the wall thickness of the electrode depending upon the depth of current penetration into the electrode as determined by the equation: δ ≈ 5030 √ ρ/μf (cm) ρ:Specific resistance of the electrode (Ω-cm) μ:Specific permeability of the electrode f:Frequency, cycles per second, and conduit means for discharging furnace off-gases and for charging raw materials into the furnace through said hollow electrode, said gases serving to pre-heat the raw materials.
Claim 3
Dependent Claim
23 words
An electric smelting furnace as set forth in claim 1 further including means for charging a self-burning electrode agent into said hollow electrode.
Claim 4
Dependent Claim
32 words
The smelting furnace as set forth in claim 1 which includes duct means aligned with said conduit means and an electrically insulated flexible tube connecting the conduit means and the duct means.
Claim 5
Dependent Claim
32 words
The smelting furnace as set forth in claim 2 which includes duct means aligned with said conduit means and an electrically insulated flexible tube connecting the conduit means and the duct means.
Claim 6
Dependent Claim
21 words
An electric smelting furnace as set forth in claim 1 further including a water cooling device for cooling said hollow electrode.
Claim 7
Dependent Claim
21 words
An electric smelting furnace as set forth in claim 2 further including a water cooling device for cooling said hollow electrode.
Claim 8
Dependent Claim
21 words
An electric smelting furnace as set forth in claim 3 further including a water cooling device for cooling said hollow electrode.
Claim 9
Dependent Claim
21 words
An electric smelting furnace as set forth in claim 4 further including a water cooling device for cooling said hollow electrode.
Claim 10
Dependent Claim
48 words
An electric smelting furnace as set forth in claim 1 wherein said hollow electrode is electrically connected to a generator through a total system controller so that the optimum frequency and current for the operation of the furnace may be supplied from said generator to said hollow electrode.
Claim 11
Dependent Claim
48 words
An electric smelting furnace as set forth in claim 2 wherein said hollow electrode is electrically connected to a generator through a total system controller so that the optimum frequency and current for the operation of the furnace may be supplied from said generator to said hollow electrode.
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) | 1982-04-02 | 1982-10-02 | 1983-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-02 | 1986-10-02 | 1987-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-02 | 1990-10-02 | 1991-04-03 | $7700.00 | Window Closed / Lapsed |