US4892475A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ignition system and method for post-mixed burner
Assignee: Praxair Technology Inc
•
Filing: 1988-12-08
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Granted: 1990-01-09
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Expires: 2008-12-08
Abstract
Abstract An ignition system and method for a post-mixed burner characterized by an igniter comprising a tube for igniter oxidant flow and having an electrode therein, said tube positioned within the fuel passage but recessed from the discharge end of the fuel passage and from the combustion zone.
Inventors
- 👤 Dennis R. Farrenkopf
- 👤 William J. Snyder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:36
CPC Classifications
F; F23; F23D; F23D14/00; F23D14/32; F23D14/20; F23D14/22; F23Q; F23Q3/00; F23Q3/006
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
167 words
A method for igniting a combustible mixture comprising: (A) passing main oxidant into a combustion zone from the discharge end of a main oxidant passage; (B) passing fuel into the combustion zone, separately from the main oxidant, from the discharge end of a fuel passage to form a combustible mixture in the combustion zone; (C) passing igniter oxidant having an oxygen concentration greater than that of air through a tube containing an electrode into the fuel passage at an angle not exceeding 45 degrees to the direction in which the fuel is flowing toward the discharge end, at a point recessed from the discharge end of the fuel passage; (D) creating a spark from the electrode to cause combustion of fuel and igniter oxidant within the fuel passage; (E) passing combusting fuel and igniter oxidant from the fuel passage into the combustion zone to ignite the combustible mixture; and (F) terminating the flow of igniter oxidant while maintaining the flow of main oxidant into the combustion zone.
Claim 2
Independent Claim
167 words
A method for igniting a combustible mixture comprising: (A) passing main oxidant into a combustion zone from the discharge end of a main oxidant passage; (B) passing fuel into the combustion zone, separately from the main oxidant, from the discharge end of a fuel passage to form a combustible mixture in the combustion zone; (C) passing igniter oxidant having an oxygen concentration greater than that of air through a tube containing an electrode into the fuel passage at an angle not exceeding 45 degrees to the direction in which the fuel is flowing toward the discharge end, at a point recessed from the discharge end of the fuel passage; (D) creating a spark from the electrode to cause combustion of fuel and igniter oxidant within the fuel passage; (E) passing combusting fuel and igniter oxidant from the fuel passage into the combustion zone to ignite the combustible mixture; and (F) terminating the flow of igniter oxidant while maintaining the flow of main oxidant into the combustion zone.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein the main oxidant is technically pure oxygen.
Claim 4
Dependent Claim
12 words
The method of claim 1 wherein the main oxidant is oxygen-enriched air.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein the igniter oxidant is passed through the tube at a flow rate within the range of from 8 to 50 cfh.
Claim 6
Dependent Claim
27 words
The method of claim 1 wherein the igniter oxidant is passed through the tube into the fuel passage proximate to the inside wall of the fuel passage.
Claim 7
Dependent Claim
33 words
The method of claim 1 wherein the igniter oxidant is passed through the tube into the fuel passage in substantially the same direction in which the fuel is flowing toward the discharge end.
Claim 8
Dependent Claim
18 words
The method of claim 1 wherein the igniter oxidant has an oxygen concentration of at least 30 percent.
Claim 9
Dependent Claim
129 words
A post-mixed burner comprising: (A) a main oxidant passage having a discharge end for supplying main oxidant into a combustion zone; (B) a fuel passage having a discharge end for supplying fuel into the combustion zone separately from the main oxidant; and (C) an igniter positioned within the fuel passage at an angle not exceeding 45 degrees to the direction of the fuel flow toward the discharge end, and recessed from the discharge end of the fuel passage, said igniter comprising a tube in flow communication with a source of oxidant having an oxygen concentration greater than that of air, and an electrode positioned within the tube, and further comprising means to terminate the flow of igniter oxidant while maintaining the flow of main oxidant into the combustion zone.
Claim 10
Dependent Claim
129 words
A post-mixed burner comprising: (A) a main oxidant passage having a discharge end for supplying main oxidant into a combustion zone; (B) a fuel passage having a discharge end for supplying fuel into the combustion zone separately from the main oxidant; and (C) an igniter positioned within the fuel passage at an angle not exceeding 45 degrees to the direction of the fuel flow toward the discharge end, and recessed from the discharge end of the fuel passage, said igniter comprising a tube in flow communication with a source of oxidant having an oxygen concentration greater than that of air, and an electrode positioned within the tube, and further comprising means to terminate the flow of igniter oxidant while maintaining the flow of main oxidant into the combustion zone.
Claim 11
Dependent Claim
28 words
The burner of claim 8 wherein the main oxidant passage is a central passage and the fuel passage is concentrically oriented around and along the main oxidant passage.
Claim 12
Dependent Claim
27 words
The burner of claim 8 wherein the fuel passage is a central passage and the main oxidant passage is concentrically oriented around and along the fuel passage.
Claim 13
Dependent Claim
19 words
The burner of claim 8 wherein the fuel passage and the main oxidant passage are oriented side by side.
Claim 14
Dependent Claim
22 words
The burner of claim 8 wherein the fuel passage and main oxidant passage discharge ends are both in substantially the same plane.
Claim 15
Dependent Claim
23 words
The burner of claim 8 wherein the igniter is positioned within the fuel passage proximate to the inside wall of the fuel passage.
Claim 16
Dependent Claim
26 words
The burner of claim 8 wherein the igniter is positioned within the fuel passage in the same direction as the fuel flow toward the discharge end.
Claim 17
Dependent Claim
19 words
The burner of claim 8 wherein the electrode is electrically insulated along its length except for the end portion.
Claim 18
Dependent Claim
18 words
The burner of claim 8 wherein the electrode tip is flush with the end of the igniter tube.
Claim 19
Dependent Claim
18 words
The burner of claim 8 wherein the electrode tip is recessed from the end of the igniter tube.
Claim 20
Dependent Claim
20 words
The burner of claim 9 wherein the igniter is recessed within the fuel passage by from 4 to 12 inches.
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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) | 1993-01-08 | 1993-07-10 | 1994-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-08 | 1997-07-10 | 1998-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-08 | 2001-07-10 | 2002-01-09 | $7700.00 | Window Closed / Lapsed |