Patent US3947360A successfully refreshed from Google Patents.
Patent US4329932A successfully refreshed from Google Patents.
US4329932A
Expired / Lapsed
US
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Method of burning fuel with lowered nitrogen-oxides emission
Assignee: Mitsubishi Heavy Industries Ltd
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Filing: 1980-06-03
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Granted: 1982-05-18
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Expires: 2000-06-03
Abstract
Abstract A method of burning fuel with lowered emission of nitrogen oxides comprises feeding pulverized fuel to the main burner in a combustion furnace and additionally feeding pulverized fuel to the region of the furnace where the first fuel is about to conclude its combustion, using inert gas with or without a low oxygen content as a conveying fluid, while supplying oxygen or air to a region downstream of the region for fuel addition.
Inventors
- 👤 Yasuro Takahashi
- 👤 Masayasu Sakai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:16
CPC Classifications
F; F23; F23C; F23C6/00; F23C6/04; F23C6/045; F23C6/047; F23K; F23K3/00; F23K3/02; F23C2201/00; F23C2201/30; F23C2201/301
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
84 words
A method of burning fuel with a lower emission of nitrogen oxides, which comprises feeding initial pulverized solid fuel and initial air for combustion to the main burner in a combustion furnace and feeding additional pulverized solid fuel to the region of said furnace where the combustion of the initial fuel is about to conclude, said additional fuel being conveyed by means of an inert gas having from 0 to about 10% oxygen admixed, which conveying gas enters the furnace with the additional fuel.
Claim 2
Independent Claim
84 words
A method of burning fuel with a lower emission of nitrogen oxides, which comprises feeding initial pulverized solid fuel and initial air for combustion to the main burner in a combustion furnace and feeding additional pulverized solid fuel to the region of said furnace where the combustion of the initial fuel is about to conclude, said additional fuel being conveyed by means of an inert gas having from 0 to about 10% oxygen admixed, which conveying gas enters the furnace with the additional fuel.
Claim 3
Dependent Claim
45 words
The method of claim 1 wherein a tertiary gas which is oxygen or air is introduced into a region of the furnace which is downstream of the region in which the additional fuel is added, to provide additional air for combustion of any uncombusted fuel.
Claim 4
Dependent Claim
13 words
The method of claim 1 or 2 wherein the inert gas is nitrogen.
Claim 5
Dependent Claim
11 words
The method of claim 3 wherein the admixed oxygen is present.
Claim 6
Dependent Claim
17 words
The method of claim 4 wherein the admixed oxygen is present in an amount up to 5%.
Claim 7
Dependent Claim
12 words
The method of claim 3 wherein the conveying gas is substantially nitrogen.
Claim 8
Dependent Claim
40 words
The method of claim 1 wherein the conveying gas is substantially nitrogen and a tertiary gas which is air is supplied to a region of the furnace which is downstream of the region in which the additional fuel is added.
Claim 9
Dependent Claim
21 words
The method of claim 7 wherein the initial fuel is conveyed by at least part of the initial air for combustion.
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) | 1985-05-17 | 1985-11-16 | 1986-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-17 | 1989-11-16 | 1990-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-17 | 1993-11-16 | 1994-05-18 | $7700.00 | Window Closed / Lapsed |