Patent US3727562A successfully refreshed from Google Patents.
US3727562A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three-stage combustion
Assignee: Lummus Technology LLC
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Filing: 1971-12-13
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Granted: 1973-04-17
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Expires: 1991-12-13
Abstract
Abstract A three-stage combustion process is disclosed in which solid carbonaceous fuel is burned with a deficiency of air in a first zone leaving unburned fuel and producing a flue gas rich in CO. The unburned fuel is separated from the first zone flue gas and burned in a second zone with an excess of air to produce a flue gas containing excess oxygen. The flue gases from the first and second zones are then burned in a third zone to complete the combustion process with the total amount of air used in the first and second zones being approximately the stoichiometric amount required for complete combustion.
Inventors
- 👤 W Bauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:34
CPC Classifications
F; F23; F23C; F23C6/00; F23C6/04; F23B; F23B2700/00; F23B2700/009
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
37 words
A method as recited in claim 1 wherein the total amount of air introduced into said first zone and said second zone is approximately equal to that theoretically required for burning under conditions corresponding to stoichiometric conditions.
Claim 2
Dependent Claim
40 words
A method as recited in claim 2 wherein the total amount of air introduced into said first and second zones is no greater than 1 percent in excess of that theoretically required for burning under conditions corresponding to stoichiometric conditions.
Claim 3
Dependent Claim
52 words
A method as recited in claim 1 wherein said portion of said fuel remaining unburned after said first combustion zone is between 20 percent and 70 percent of the fuel and wherein the percentage of fuel reacted in said first combustion zone which produces CO is between 40 percent and 80 percent.
Claim 4
Dependent Claim
41 words
A method as recited in claim 4 wherein said portion of said fuel remaining unburned after the first combustion zone is about 60 percent of the fuel and wherein the ratio CO/CO2 in said first zone flue gas is about 7:3.
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) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |