US4274836A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for improving bed firing characteristics and inhibiting coalescence of coal pellets
Assignee: CTI-NUCLEAR Inc (FORMERLY MCDOWELL-WELLMAN COMPANY)
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Filing: 1979-04-20
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Granted: 1981-06-23
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Expires: 1999-04-20
Abstract
Abstract There is disclosed a method of reducing the swelling characteristics and bed characteristics of a pelletized fuel during a sintering operation. The method comprises the steps of pulverizing the coal to form a powdery mass, forming the mass into discrete pellets, providing a coating on the pellets with soluble salts, burnt lime, or hydrated lime, and heating the pellets to a temperature exceeding 800° F.
Inventors
- 👤 Thomas E. Ban
- 👤 William H. Marlowe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:57
CPC Classifications
C; C10; C10L; C10L5/00; C10L5/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
73 words
A method of reducing the swelling characteristics and bed coalescence characteristics of a pelletized fuel during a sintering operation comprising the steps of pulverizing the coal to form a powdery mass, forming said mass into discrete pellets, providing on the surface of said pellets a coating substance selected from the group consisting of sodium carbonate, burnt lime, and hydrated lime, drying said pellets and heating said pellets to a temperature exceeding 800° F.
Claim 2
Independent Claim
73 words
A method of reducing the swelling characteristics and bed coalescence characteristics of a pelletized fuel during a sintering operation comprising the steps of pulverizing the coal to form a powdery mass, forming said mass into discrete pellets, providing on the surface of said pellets a coating substance selected from the group consisting of sodium carbonate, burnt lime, and hydrated lime, drying said pellets and heating said pellets to a temperature exceeding 800° F.
Claim 3
Dependent Claim
15 words
A method according to claim 1, wherein powdered limestone is mixed with said powdery mass.
Claim 4
Dependent Claim
17 words
A method according to claim 2, wherein said powdered limestone is present in amounts of about 20%.
Claim 5
Dependent Claim
29 words
A method according to claim 1, wherein the coating substance is initially mixed with the powdery mass and migrates to the surface of the pellets during the drying step.
Claim 6
Dependent Claim
13 words
A method according to claim 4, wherein said coating substance is sodium carbonate.
Claim 7
Dependent Claim
22 words
A method according to claim 5, wherein said sodium carbonate is present in amounts of between 1 and 5 percent by weight.
Claim 8
Dependent Claim
24 words
A method according to claim 1, wherein said coated material is deposited directly on the surface of the pellet prior to drying the pellet.
Claim 9
Dependent Claim
12 words
A method according to claim 7, wherein said coating material is lime.
Claim 10
Dependent Claim
21 words
A method according to claim 8, wherein said lime is present in amounts of between 4 and 10 percent by weight.
Claim 11
Dependent Claim
22 words
A method according to claim 1, wherein recycled fired pellets are layered onto the discrete green pellets prior to heating the pellets.
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US1860743A
Cited
US2336154A
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US2729598A
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Cited
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US4148613A
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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) | 1984-06-22 | 1984-12-22 | 1985-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-22 | 1988-12-22 | 1989-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-22 | 1992-12-22 | 1993-06-23 | $7700.00 | Window Closed / Lapsed |