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US4431400A
Expired / Lapsed
US
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Ignition system for post-mixed burner
Assignee: Praxair Technology Inc
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Filing: 1981-08-04
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Granted: 1984-02-14
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Expires: 2001-08-04
Abstract
Abstract An ignition system for post-mixed gas burner which achieves reliable ignition without requiring an expensive spark source protection device, or a means to promote fuel-oxidant mixing, or a large amount of electricity, or a separate pilot light.
Inventors
- 👤 Hisashi Kobayashi
- 👤 Raymond H. Miller
- 👤 John E. Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:43
CPC Classifications
F; F23; F23Q; F23Q3/00; F23Q3/008
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
165 words
A post-mixed burner apparatus capable of igniting a combustible gas mixture of fuel and oxidant discharged from the burner comprising: a first passage means for supplying fuel gas and a second passage means for supplying oxidant gas, both of said passage means terminating at the discharge end of said apparatus, characterized by an ignition system consisting of: (1) said first passage means being electrically conductive; (2) said second passage means being electrically conductive and means spacing said second passage means from said first passage means such that the breakdown voltage between said first and second passage means is lowest at the discharge end of said apparatus; and (3) means for applying an electrical potential across said first and second passage means, whereby, when an electrical potential greater than said lowest breakdown voltage is applied across said first and second passage means, an electrical discharge occurs, in an essentially straight line, only across the space between said first and second passage means at the discharge end.
Claim 2
Dependent Claim
165 words
A post-mixed burner apparatus capable of igniting a combustible gas mixture of fuel and oxidant discharged from the burner comprising: a first passage means for supplying fuel gas and a second passage means for supplying oxidant gas, both of said passage means terminating at the discharge end of said apparatus, characterized by an ignition system consisting of: (1) said first passage means being electrically conductive; (2) said second passage means being electrically conductive and means spacing said second passage means from said first passage means such that the breakdown voltage between said first and second passage means is lowest at the discharge end of said apparatus; and (3) means for applying an electrical potential across said first and second passage means, whereby, when an electrical potential greater than said lowest breakdown voltage is applied across said first and second passage means, an electrical discharge occurs, in an essentially straight line, only across the space between said first and second passage means at the discharge end.
Claim 3
Dependent Claim
14 words
The apparatus of claim 1 wherein said first and second passage means are tubes.
Claim 4
Dependent Claim
14 words
The apparatus of claim 2 wherein said first passage means is a cylindrical tube.
Claim 5
Dependent Claim
14 words
The apparatus of claim 2 wherein said second passage means is a cylindrical tube.
Claim 6
Dependent Claim
15 words
The apparatus of claim 2 wherein both first and second passage means are cylindrical tubes.
Claim 7
Dependent Claim
17 words
The apparatus of claim 5 wherein said first and second passage means are parallel along their length.
Claim 8
Dependent Claim
16 words
The apparatus of claim 6 wherein said first and second passage means are concentric cylindrical tubes.
Claim 9
Dependent Claim
43 words
The apparatus of claim 1 wherein said spacing means comprises an electrically conductive tab connected to at least one passage means at the discharge end so as to minimize the breakdown voltage between the first and second passage means at the discharge end.
Claim 10
Dependent Claim
42 words
The apparatus of claim 1 wherein said spacing means comprises electrical insulation between said first and second passage means except at the discharge end so as to minimize the breakdown voltage between the first and second passage means at the discharge end.
Claim 11
Dependent Claim
168 words
A process for igniting a combustible gaseous mixture discharged from a burner comprising: (A) causing a stream of fuel gas and a stream of oxidant gas to flow in the same direction through first and second passages which are electrically conductive, insulated from each other and terminate at the discharge end of the burner; (B) maintaining said flowing streams separated from each other by said first passage; (C) mixing said gas streams upon discharge from said passages at the discharge end of the burner; (D) spacing said second passage from said first passage such that the breakdown voltage between said first and second passages is lowest at the discharge end of the burner; and (E) applying an electrical potential greater than said lowest breakdown voltage across said first and second passages such that an electrical discharge occurs, in an essentially straight line, only across the space between said first and second passage at the discharge end of the burner, which space contains essentially only one of the gases.
Claim 12
Dependent Claim
168 words
A process for igniting a combustible gaseous mixture discharged from a burner comprising: (A) causing a stream of fuel gas and a stream of oxidant gas to flow in the same direction through first and second passages which are electrically conductive, insulated from each other and terminate at the discharge end of the burner; (B) maintaining said flowing streams separated from each other by said first passage; (C) mixing said gas streams upon discharge from said passages at the discharge end of the burner; (D) spacing said second passage from said first passage such that the breakdown voltage between said first and second passages is lowest at the discharge end of the burner; and (E) applying an electrical potential greater than said lowest breakdown voltage across said first and second passages such that an electrical discharge occurs, in an essentially straight line, only across the space between said first and second passage at the discharge end of the burner, which space contains essentially only one of the gases.
Claim 13
Dependent Claim
23 words
The process of claim 10 wherein fuel gas flows through the first passage means and oxidant gas flows through the second passage means.
Claim 14
Dependent Claim
23 words
The process of claim 10 wherein fuel gas flows through the second passage means and oxidant gas flows through the first passage means.
Claim 15
Dependent Claim
12 words
The process of claim 10 wherein said fuel gas is natural gas.
Claim 16
Dependent Claim
13 words
The process of claim 10 wherein said oxidant gas is substantially pure oxygen.
Claim 17
Dependent Claim
11 words
The process of claim 10 wherein said oxidant gas is air.
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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) | 1987-02-13 | 1987-08-15 | 1988-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-13 | 1991-08-15 | 1992-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-13 | 1995-08-15 | 1996-02-14 | $7700.00 | Window Closed / Lapsed |