US3788796A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel burner
Assignee: Babcock and Wilcox Co
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Filing: 1973-05-09
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Granted: 1974-01-29
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Expires: 1993-05-09
Abstract
Abstract An improved pulverized fuel burning method and apparatus having means for enhancing the fuel-air mixture passing therethrough and including three separately controlled passageways delivering the air necessary for combustion of the fuel.
Inventors
- 👤 B Krippene
- 👤 M Peterson
- 👤 D Marshall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:23
CPC Classifications
F; F23; F23C; F23C7/00; F23C7/008
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
183 words
In combination with a boundary wall of a furnace, at least one burner port formed in the boundary wall, a burner wall spaced from the boundary wall to form a windbox therebetween to which a portion of the necessary combustion air is supplied, an improved pulverized fuel burner comprising a tubular nozzle having an inlet and an outlet end, said nozzle having at least a portion thereof disposed within the windbox and having the outlet end opening adjacent said port, means for supplying a mixture of pulverized fuel and the remaining portion of the necessary combustion air to the nozzle for discharge into said port, a first and second sleeve member disposed within the windbox to direct the air therefrom to said port, the first sleeve member having a portion thereof concentrically spaced about the nozzle to form an inner annular passageway therebetween, the second sleeve member having a portion thereof concentrically spaced about the first sleeve member to form an outer annular passageway therebetween, and separate damper means associated with each of said passageways for apportioning the flow of windbox air therebetween.
Claim 2
Dependent Claim
183 words
In combination with a boundary wall of a furnace, at least one burner port formed in the boundary wall, a burner wall spaced from the boundary wall to form a windbox therebetween to which a portion of the necessary combustion air is supplied, an improved pulverized fuel burner comprising a tubular nozzle having an inlet and an outlet end, said nozzle having at least a portion thereof disposed within the windbox and having the outlet end opening adjacent said port, means for supplying a mixture of pulverized fuel and the remaining portion of the necessary combustion air to the nozzle for discharge into said port, a first and second sleeve member disposed within the windbox to direct the air therefrom to said port, the first sleeve member having a portion thereof concentrically spaced about the nozzle to form an inner annular passageway therebetween, the second sleeve member having a portion thereof concentrically spaced about the first sleeve member to form an outer annular passageway therebetween, and separate damper means associated with each of said passageways for apportioning the flow of windbox air therebetween.
Claim 3
Dependent Claim
19 words
The combination according to claim 1 including damper means for regulating the quantity of air flowing through said nozzle.
Claim 4
Dependent Claim
22 words
The combination according to claim 1 including separate means disposed outside of the windbox for positioning each of said separate damper means.
Claim 5
Dependent Claim
22 words
The combination according to claim 1 including an inlet communicating with said inner annular passageway and housing the damper means associated therewith.
Claim 6
Dependent Claim
22 words
The combination according to claim 1 including an inlet communicating with said outer annular passageway and housing the damper means associated therewith.
Claim 7
Dependent Claim
14 words
The combination according to claim 1 including a venturi section disposed within said nozzle.
Claim 8
Dependent Claim
33 words
The combination according to claim 6 including an adjustable rod means extending through at least a portion of said venturi section and cooperating therewith to enhance the fuel-air mixture exiting from said nozzle.
Claim 9
Independent Claim
180 words
A method of inhibiting the formation of nitric oxide from the combustion of fuel including at least one burner port, means for supplying pulverized fuel and combustion air to said port, a pulverized fuel burner having a nozzle defining a central passageway, means forming an inner annular passageway about said nozzle, means forming an outer annular passageway about said inner passageway and means apportioning the flow of combustion air between said passageways and comprising the steps of: conveying a portion of the necessary combustion air through the inner and outer annular passageways for discharge into said burner port, conveyinG a mixture of pulverized fuel and the remaining portion of the necessary combustion air through the central passageway for discharge into said burner port, regulating the quantity of combustion air passing through the central passageway to provide a fuel ignition zone within a reducing atmosphere, regulating the quantity of air passing through the inner annular passageway to stabilize the ignition zone, and regulating the quantity of combustion air passing through the outer annular passageway to achieve complete combustion of the fuel.
Claim 10
Independent Claim
180 words
A method of inhibiting the formation of nitric oxide from the combustion of fuel including at least one burner port, means for supplying pulverized fuel and combustion air to said port, a pulverized fuel burner having a nozzle defining a central passageway, means forming an inner annular passageway about said nozzle, means forming an outer annular passageway about said inner passageway and means apportioning the flow of combustion air between said passageways and comprising the steps of: conveying a portion of the necessary combustion air through the inner and outer annular passageways for discharge into said burner port, conveyinG a mixture of pulverized fuel and the remaining portion of the necessary combustion air through the central passageway for discharge into said burner port, regulating the quantity of combustion air passing through the central passageway to provide a fuel ignition zone within a reducing atmosphere, regulating the quantity of air passing through the inner annular passageway to stabilize the ignition zone, and regulating the quantity of combustion air passing through the outer annular passageway to achieve complete combustion of the fuel.
Claim 11
Dependent Claim
26 words
The method according to claim 8 wherein the quantity of combustion air passing through said central passageway is between 15 and 30 percent of stoichiometric air.
Claim 12
Dependent Claim
27 words
The method according to claim 8 wherein the quantity of combustion air passing through said inner annular passageway is between 35 and 45 percent of stoichiometric air.
Claim 13
Dependent Claim
27 words
The method according to claim 8 wherein the quantity of combustion air passing through said outer annular passageway is between 55 and 65 percent of stoichiometric air.
Claim 14
Dependent Claim
18 words
The method according to claim 8 including the step of varying the fuel-air mixture velocity through said nozzle.
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) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |