Patent US6164221A successfully refreshed from Google Patents.
US6164221A
Expired / Lapsed
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Method for reducing unburned carbon in low NOx boilers
Assignee: Electric Power Research Institute
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Filing: 1998-12-30
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Granted: 2000-12-26
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Expires: 2018-12-30
Abstract
Abstract The invention provides a method which includes the step of locating a burner of a low NOx boiler that produces a disproportionately high quantity of unburned carbon. The air-to-fuel ratio at the burner is then increased to decrease the percentage of unburned carbon attributable to the burner. The air-to-fuel ratio at a second burner of the low NOx boiler is reduced to maintain a substantially constant total air-to-fuel ratio in the low NOx boiler.
Inventors
- 👤 Anthony Facchiano
- 👤 Richard A. Brown
- 👤 Wate T. Bakker
- 👤 Robert R. Hardman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:11
CPC Classifications
F; F23; F23C; F23C6/00; F23C6/04; F23C6/045; F23C6/047; F23D; F23D1/00; F23J; F23J3/00; F23J3/02; F23J3/023; F23L; F23L9/00; F23L9/04; F23N; F23N1/00; F23N1/02; F23N1/022; F23C2201/00; F23C2201/10; F23C2201/101; F23D2900/00; F23D2900/00016; F23K; F23K2201/00; F23K2201/10; F23K2201/101; F23N2239/00; F23N2239/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
84 words
A method to reduce unburned carbon in a low NOx boiler, said method comprising the steps of: locating a first burner that produces a higher quantity of unburned carbon than other burners of the low NOx boiler; increasing the air-to-fuel ratio at said first burner to decrease a percentage of unburned carbon attributable to said first burner; and reducing the air-to-fuel ratio at a second burner of said low NOx boiler to maintain a substantially constant total air-to-fuel ratio in said low NOx boiler.
Claim 2
Independent Claim
84 words
A method to reduce unburned carbon in a low NOx boiler, said method comprising the steps of: locating a first burner that produces a higher quantity of unburned carbon than other burners of the low NOx boiler; increasing the air-to-fuel ratio at said first burner to decrease a percentage of unburned carbon attributable to said first burner; and reducing the air-to-fuel ratio at a second burner of said low NOx boiler to maintain a substantially constant total air-to-fuel ratio in said low NOx boiler.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said locating step includes the step of operating a three-dimensional combustion fluid dynamic module to locate said first burner.
Claim 4
Dependent Claim
20 words
The method of claim 1 wherein said increasing step includes the step of increasing oxygen discharged at said first burner.
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein said increasing step includes the step of eliminating a coarse fraction of pulverized coal fed to said first burner.
Claim 6
Dependent Claim
45 words
The method of claim 1 wherein said increasing step includes the step of classifying coal mill discharge that produces a burner feed stream for said first burner, such that substantially all fuel particles in said burner feed stream are less than 250 micro-meter in diameter.
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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) | 2003-12-26 | 2004-06-26 | 2004-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-12-26 | 2008-06-26 | 2008-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-12-26 | 2012-06-26 | 2012-12-26 | $7700.00 | Window Closed / Lapsed |