Patent US5076779A successfully refreshed from Google Patents.
US5076779A
Expired / Lapsed
US
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Segregated zoning combustion
Assignee: Praxair Technology Inc
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Filing: 1991-04-12
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Granted: 1991-12-31
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Expires: 2011-04-12
Abstract
Abstract A combustion method wherein separate oxidant mixing zones and fuel reaction zones are established in a combustion zone to dilute oxidant and combust fuel under conditions which dampen NO x formation.
Inventors
- 👤 Hisashi Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:34
CPC Classifications
F; F23; F23C; F23C9/00; F23C9/006; C; C03; C03B; C03B5/00; C03B5/16; C03B5/235; C03B5/2353; F23C7/00; F23C7/02; F23C2900/00; F23C2900/09002; Y; Y02; Y02P; Y02P40/00; Y02P40/50
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
210 words
A method for carrying out combustion with low NO x generation comprising: (A) providing a combustion zone containing an atmosphere of furnace gases at a temperature exceeding 1000° F.; (B) injecting into the combustion zone an oxidant stream and mixing furnace gases with the injected oxidant in an oxidant mixing zone within the combustion zone to produce an oxidant mixture having an oxygen concentration which is not more than 10 percent; (C) flowing the oxidant mixture out from the oxidant mixing zone to provide additional furnace gases to the combustion zone; (D) injecting into the combustion zone a fuel steam, mixing furnace gases with the injected fuel in a fuel reaction zone within the combustion zone, and carrying out combustion with low NO x generation within the fuel reaction zone to produce a fuel reaction mixture; (E) flowing the fuel reaction mixture out from the fuel reaction zone to provide additional furnace gases to the combustion zone; (F) creating sufficient mixing within the combustion zone so that the composition of the atmosphere at points within the combustion zone outside of the oxidant mixing zone and the fuel reaction zone is substantially the same; and (G) maintaining the oxidant mixing zone and the fuel reaction zone segregated within the combustion zone.
Claim 2
Independent Claim
210 words
A method for carrying out combustion with low NO x generation comprising: (A) providing a combustion zone containing an atmosphere of furnace gases at a temperature exceeding 1000° F.; (B) injecting into the combustion zone an oxidant stream and mixing furnace gases with the injected oxidant in an oxidant mixing zone within the combustion zone to produce an oxidant mixture having an oxygen concentration which is not more than 10 percent; (C) flowing the oxidant mixture out from the oxidant mixing zone to provide additional furnace gases to the combustion zone; (D) injecting into the combustion zone a fuel steam, mixing furnace gases with the injected fuel in a fuel reaction zone within the combustion zone, and carrying out combustion with low NO x generation within the fuel reaction zone to produce a fuel reaction mixture; (E) flowing the fuel reaction mixture out from the fuel reaction zone to provide additional furnace gases to the combustion zone; (F) creating sufficient mixing within the combustion zone so that the composition of the atmosphere at points within the combustion zone outside of the oxidant mixing zone and the fuel reaction zone is substantially the same; and (G) maintaining the oxidant mixing zone and the fuel reaction zone segregated within the combustion zone.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein a plurality of oxidant streams are injected into the combustion zone.
Claim 4
Dependent Claim
18 words
The method of claim 2 wherein a plurality of oxidant mixing zones are established within the combustion zone.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein a plurality of fuel streams are injected into the combustion zone.
Claim 6
Dependent Claim
18 words
The method of claim 4 wherein a plurality of fuel reaction zones are established within the combustion zone.
Claim 7
Dependent Claim
10 words
The method of claim 1 wherein the oxidant is air.
Claim 8
Dependent Claim
11 words
The method of claim 1 wherein the oxidant is oxygen-enriched air.
Claim 9
Dependent Claim
12 words
The method of claim 1 wherein the oxidant is technically pure oxygen.
Claim 10
Dependent Claim
10 words
The method of claim 1 wherein the fuel comprises methane.
Claim 11
Dependent Claim
23 words
The method of claim 1 wherein the fuel and oxidant are injected into the combustion zone from different sides of the combustion zone.
Claim 12
Dependent Claim
23 words
The method of claim 10 wherein the fuel and oxidant are injected into the combustion zone from opposite sides of the combustion zone.
Claim 13
Dependent Claim
29 words
The method of claim 1 wherein the fuel and oxidant are injected into the combustion zone in a manner to set up a recirculating flow within the combustion zone.
Claim 14
Dependent Claim
15 words
The method of claim 1 wherein the temperature of the furnace gases exceeds 1400° F.
Claim 15
Dependent Claim
26 words
The method of claim 1 wherein the oxidant mixture produced in the oxidant mixing zone has an oxygen concentration which is not more than 5 percent.
Claim 16
Dependent Claim
17 words
The method of claim 1 wherein the fuel is substantially completely combusted within the fuel reaction zone.
Claim 17
Dependent Claim
20 words
The method of claim 1 wherein the combustion zone atmosphere outside of the fuel reaction zone contains substantially no fuel.
Claim 18
Dependent Claim
18 words
The method of claim 1 wherein stabilizing oxidant is injected into the combustion zone proximate the fuel stream.
Claim 19
Dependent Claim
17 words
The method of claim 17 wherein the stabilizing oxidant is an annular stream around the fuel stream.
References Cited (Backward Citations)
US4496306A
Cited
US4439137A
Cited
US4378205A
Cited
US4541796A
Cited
US4408982A
Cited
US4878829A
Cited
US4907961A
Cited
US4863371A
Cited
US4969814A
Cited
US4946382A
Cited
US4988285A
Cited
US4957050A
Cited
US4973346A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-30 | 1995-07-01 | 1995-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-30 | 1999-07-01 | 1999-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-30 | 2003-07-01 | 2003-12-31 | $7700.00 | Window Closed / Lapsed |