US3828107A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plasma smelting furnace
Assignee: Daido Steel Co Ltd
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Filing: 1971-05-12
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Granted: 1974-08-06
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Expires: 1991-05-12
Abstract
Abstract The present invention discloses a plasma smelting furnace which is formed by enclosing the outside of a refractory which forms the smelting chamber with a metallic plate completely and the smelting chamber is sealed against the outer atmosphere, and further characterized by the fact that the air in the inner space enclosed by the metallic plate is substituted by inert gas.
Inventors
- 👤 S Sone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:53
CPC Classifications
F; F27; F27D; F27D11/00; F27D11/08; A; A44; A44C; A44C17/00; B; B01; B01J; B01J19/00; B01J19/08; C; C10; C10J; C10J3/00; C10J3/02; C10J3/06; C10J3/18; C10J3/20; C10J3/57; C10J3/72; C10J3/74; F27B; F27B14/00; F27B14/08; F27B14/14; F27B3/00; F27B3/08; C10J2200/00; C10J2200/09; C10J2300/00; C10J2300/09; C10J2300/0953; C10J2300/0956; C10J2300/12; C10J2300/123; C10J2300/1238; C10J2300/1246
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
58 words
A plasma smelting furnace in which the plasma jet is used as the heat source comprising: a. a refractory forming the smelting chamber; b. means to completely enclose the outside of said smelting chamber to preclude the passage of gas between the smelting chamber and the open air except for an opening to exhaust the used plasma gas.
Claim 2
Dependent Claim
58 words
A plasma smelting furnace in which the plasma jet is used as the heat source comprising: a. a refractory forming the smelting chamber; b. means to completely enclose the outside of said smelting chamber to preclude the passage of gas between the smelting chamber and the open air except for an opening to exhaust the used plasma gas.
Claim 3
Dependent Claim
21 words
The furnace of claim 1 in which the space between the enclosing means and refractory is filled by an inert gas.
Claim 4
Dependent Claim
28 words
The furnace of claim 1 in which the enclosure means include a separate operable cover with sealing means between the cover and the remainder of the enclosure means.
Claim 5
Dependent Claim
24 words
The furnace of claim 2 in which the opening to exhaust the used plasma gas is a gap between the plasma jet and cover.
Claim 6
Dependent Claim
14 words
The furnace of claim 1 in which the enclosure means is a metallic sheet.
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) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |