Patent US4493088A successfully refreshed from Google Patents.
US4493088A
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US
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Plasma melting furnace
Assignee: Voestalpine AG
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Filing: 1982-01-04
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Granted: 1985-01-08
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Expires: 2002-01-04
Abstract
Abstract A plasma melting furnace includes one or more plasma burners penetrating the furnace lining, in particular a plasma burner projecting vertically into the interior of the furnace. In order to ensure a most uniform stress on the lining by the heat radiation, the inner surface of the lining is designed to be inclined, converging upwardly.
Inventors
- 👤 Walter Lugscheider
- 👤 Helmut D. Kilches
- 👤 Ernst Riegler
- 👤 Ernst Zajicek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:08
CPC Classifications
H; H05; H05B; H05B7/00; F; F27; F27B; F27B3/00; F27B3/08; F27D; F27D99/00; F27D99/0001; F27D99/0006; F27D2099/0031
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
107 words
In a plasma melting furnace of the type including a furnace interior having an axis, a furnace lining surrounding said furnace interior and having an inner surface, and at least one plasma burner penetrating said furnace lining to a point above the surface of a bath within said furnace interior, in particular a plasma burner projecting vertically into said furnace interior, the improvement which is characterized in that said inner surface of said furnace lining is conical and inclined, converging upwardly at a convergent angle α, whereby heat radiation emanating from said plasma burner on a horizontal plane perpendicular to said axis is reflected into said bath.
Claim 2
Dependent Claim
107 words
In a plasma melting furnace of the type including a furnace interior having an axis, a furnace lining surrounding said furnace interior and having an inner surface, and at least one plasma burner penetrating said furnace lining to a point above the surface of a bath within said furnace interior, in particular a plasma burner projecting vertically into said furnace interior, the improvement which is characterized in that said inner surface of said furnace lining is conical and inclined, converging upwardly at a convergent angle α, whereby heat radiation emanating from said plasma burner on a horizontal plane perpendicular to said axis is reflected into said bath.
Claim 3
Dependent Claim
21 words
A plasma melting furnace as set forth in claim 1, wherein said convergent angle α amounts to between 5° and 15°.
Claim 4
Dependent Claim
21 words
A plasma melting furnace as set forth in claim 1, wherein said convergent angle α amounts to between 5° and 10°.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-08 | 1988-07-09 | 1989-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-08 | 1992-07-09 | 1993-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-08 | 1996-07-09 | 1997-01-08 | $7700.00 | Window Closed / Lapsed |