US4396394A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing a dried coal fuel having a reduced tendency to spontaneously ignite from a low rank coal
Assignee: Arch Resources Inc
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Filing: 1981-12-21
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Granted: 1983-08-02
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Expires: 2001-12-21
Abstract
Abstract A method for producing a dried coal fuel having a reduced tendency to spontaneously ignite from a low rank coal by drying the low rank coal and thereafter cooling the dried coal to a temperature below about 100° F. Optionally the dried coal is partially oxidized prior to cooling, and optionally the dried coal is mixed with a deactivating fluid.
Inventors
- 👤 Ying-Hsiao Li
- 👤 James L. Skinner
- 👤 Donald K. Wunderlich
- 👤 J. David Matthews
- 👤 Bernard F. Bonnecaze
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:02
CPC Classifications
C; C10; C10L; C10L9/00; C10L9/10; C10F; C10F5/00; C10L9/02; C10L9/06
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
245 words
A method for producing a dried particulate coal fuel having a reduced tendency to spontaneously ignite from a particulate low rank coal, said method consisting essentially of: a. charging said particulate low rank coal to a coal drying zone wherein said coal is supported on a first support means, said first support means being adapted to the flow of a hot gas upwardly through said first support means and said particulate low rank coal; b. drying said particulate low rank coal in said coal drying zone by flowing a hot gas upwardly through said first support means and said particulate low rank coal to produce a dried coal; c. recovering said dried coal from said coal drying zone; d. charging said dried coal to a coal oxidation zone; e. contacting said dried coal with a free oxygen containing gas in said coal oxidation zone to produce a dried oxidized coal; f. recovering said dried oxidized coal from said coal oxidation zone; g. charging said dried oxidized coal to a coal cooling zone wherein said dried oxidized coal is supported on a second support means, said second support means being adapted to the flow of a cooling gas upwardly through said second support means and said dried oxidized coal; and, h. cooling said dried oxidized coal in said coal cooling zone by flowing a cooling gas upwardly through said dried oxidized coal to a temperature below about 100° F. to produce a cooled dried, oxidized coal.
Claim 2
Independent Claim
245 words
A method for producing a dried particulate coal fuel having a reduced tendency to spontaneously ignite from a particulate low rank coal, said method consisting essentially of: a. charging said particulate low rank coal to a coal drying zone wherein said coal is supported on a first support means, said first support means being adapted to the flow of a hot gas upwardly through said first support means and said particulate low rank coal; b. drying said particulate low rank coal in said coal drying zone by flowing a hot gas upwardly through said first support means and said particulate low rank coal to produce a dried coal; c. recovering said dried coal from said coal drying zone; d. charging said dried coal to a coal oxidation zone; e. contacting said dried coal with a free oxygen containing gas in said coal oxidation zone to produce a dried oxidized coal; f. recovering said dried oxidized coal from said coal oxidation zone; g. charging said dried oxidized coal to a coal cooling zone wherein said dried oxidized coal is supported on a second support means, said second support means being adapted to the flow of a cooling gas upwardly through said second support means and said dried oxidized coal; and, h. cooling said dried oxidized coal in said coal cooling zone by flowing a cooling gas upwardly through said dried oxidized coal to a temperature below about 100° F. to produce a cooled dried, oxidized coal.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein said particulate low rank coal is selected from the group consisting of sub-bituminous, lignite and brown coals.
Claim 4
Dependent Claim
28 words
The method of claim 2 wherein said particulate low rank coal is heated to a temperature from about 130° to about 250° F. in said coal drying zone.
Claim 5
Dependent Claim
24 words
The method of claim 2 wherein said particulate low rank coal has a water content from about 25 to about 65 weight percent water.
Claim 6
Dependent Claim
32 words
The method of claim 2 wherein from about 6 to about 25 lbs. of oxygen per ton of said dried coal are reacted with said dried coal in said coal oxidation zone.
Claim 7
Dependent Claim
29 words
The method of claim 5 wherein the water content of said dried coal is rendered by from about 1 to about 5 weight percent in said coal oxidation zone.
Claim 8
Dependent Claim
16 words
The method of claim 1 wherein said dried oxidized coal is mixed with a deactivating fluid.
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) | 1986-08-01 | 1987-01-31 | 1987-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-01 | 1991-01-31 | 1991-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-01 | 1995-01-31 | 1995-08-02 | $7700.00 | Window Closed / Lapsed |