Patent US241747A successfully refreshed from Google Patents.
Patent US4626199A successfully refreshed from Google Patents.
US4626199A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Submerged combustion calcination
Assignee: United States Gypsum Co
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Filing: 1985-04-25
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Granted: 1986-12-02
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Expires: 2005-04-25
Abstract
Abstract Gypsum is calcined by contacting it with the hot gases spewing out of a combustion tube submerged in the mass of gypsum. The formation of dead-burned anhydrite is reduced by surrounding the combustion tube with a second tube called a draft tube. Gypsum passing through the annulus between the tubes is heated by the hot gases and is ejected from the annulus to prevent repeated excursions into the hot gas zone at the muzzle of the combustion tube.
Inventors
- 👤 Larbi Bounini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:50
CPC Classifications
C; C04; C04B; C04B11/00; C04B11/02; C04B11/028; C04B11/0281
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
134 words
A calcination apparatus comprising: a kettle having a top wall, a sidewall, a bottom wall, a duct extending through the top wall for the introduction of uncalcined material into the kettle, an exhaust vent, and a port for the discharge of calcined material; a burner; a first tube extending through the top wall into the kettle, said tube communicating with the burner and having an outlet for injecting hot combustion gases from the burner into the material to be calcined; a second tube surrounding the first tube and extending beyond the outlet of the first tube, the second tube having an inlet for the material to be calcined and an outlet which is co-axial with the first tube; said first and second tubes defining a passageway between them which empties into the second tube.
Claim 2
Dependent Claim
134 words
A calcination apparatus comprising: a kettle having a top wall, a sidewall, a bottom wall, a duct extending through the top wall for the introduction of uncalcined material into the kettle, an exhaust vent, and a port for the discharge of calcined material; a burner; a first tube extending through the top wall into the kettle, said tube communicating with the burner and having an outlet for injecting hot combustion gases from the burner into the material to be calcined; a second tube surrounding the first tube and extending beyond the outlet of the first tube, the second tube having an inlet for the material to be calcined and an outlet which is co-axial with the first tube; said first and second tubes defining a passageway between them which empties into the second tube.
Claim 3
Dependent Claim
17 words
The apparatus of claim 1 wherein the duct opens directly into the inlet of the second tube.
Claim 4
Dependent Claim
19 words
The apparatus of claim 1 wherein the duct opens into the kettle beyond the inlet of the second tube.
Claim 5
Dependent Claim
42 words
The apparatus of claim 1 wherein the duct has three legs in the shape of an inverted Y, the upper leg of which extends through the top wall, and a gate which is operable to close either of the other two legs.
Claim 6
Dependent Claim
40 words
The apparatus of claim 1 wherein the kettle is frustoconical and co-axial with the first tube, said kettle having a smaller diameter at the bottom and having a co-axial, heat-resistant deflector projecting upward from the bottom toward the first tube.
Claim 7
Dependent Claim
15 words
The apparatus of claim 5 wherein the outlet of the first tube has converging walls.
Claim 8
Dependent Claim
26 words
The apparatus of claim 5 wherein there is a gap of at least about 1.5 inches between the outlet of the second tube and the deflector.
Claim 9
Dependent Claim
13 words
The apparatus of claim 5 wherein the duct communicates with the second tube.
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) | 1989-12-01 | 1990-06-02 | 1990-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-01 | 1994-06-02 | 1994-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-01 | 1998-06-02 | 1998-12-02 | $7700.00 | Window Closed / Lapsed |