US4249470A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Furnace structure
Assignee: Foster Wheeler Energy Corp
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Filing: 1979-10-02
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Granted: 1981-02-10
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Expires: 1999-10-02
Abstract
Abstract A furnace structure has a particle separator for separating a mixture of a transport fluid and pulverized coal into a coarse coal fraction and a fine coal fraction, a furnace, a burner assembly for burning the pulverized coal, and a windbox for providing combustion supporting gas to the burner assembly. The burner assembly has separate, concentrically disposed elements to burn coarse and fine coal particles under different combustion conditions to reduce the production of nitrogen oxides from the combustion of coal as a fuel. The burner assembly further includes a control nozzle for maintaining a swirling motion in the combustion flame and a separate, axially-movable adjustable sleeve for regulating the quantity flow of turbulence-free combustion-supporting air.
Inventors
- 👤 Joel Vatsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:27
CPC Classifications
F; F23; F23K; F23K1/00; F23C; F23C7/00; F23C7/002; F23C7/008; F23D; F23D1/00; F23C2201/00; F23C2201/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
180 words
In combination with a particle separator for separating a mixture of a transport fluid and pulverized coal into a coarse coal fraction having a first portion of the transport fluid and a fine coal fraction having a second portion of the transport fluid, a furnace having a combustion chamber, a burner assembly for burning the pulverized coal, and a windbox disposed adjacent to said furnace for providing combustion supporting gas to the burner assembly, said burner assembly comprising a tubular element operatively connected to said separator for receiving said coarse coal fraction; means for introducing a heating fluid to said tubular element to initiate devolutilization of said coarse coal fraction; a shell element disposed concentrically about said tubular element and operatively connected to said separator for receiving and for achieving rapid devolatilization of said fine coal fraction; and flow control means for regulating the flow of combustion supporting gas from said windbox, said tubular and said shell elements cooperating to effect combustion of the pulverized coal within said combustion chamber under stoichiometric conditions resulting in reduced production of nitrogen oxides.
Claim 2
Dependent Claim
180 words
In combination with a particle separator for separating a mixture of a transport fluid and pulverized coal into a coarse coal fraction having a first portion of the transport fluid and a fine coal fraction having a second portion of the transport fluid, a furnace having a combustion chamber, a burner assembly for burning the pulverized coal, and a windbox disposed adjacent to said furnace for providing combustion supporting gas to the burner assembly, said burner assembly comprising a tubular element operatively connected to said separator for receiving said coarse coal fraction; means for introducing a heating fluid to said tubular element to initiate devolutilization of said coarse coal fraction; a shell element disposed concentrically about said tubular element and operatively connected to said separator for receiving and for achieving rapid devolatilization of said fine coal fraction; and flow control means for regulating the flow of combustion supporting gas from said windbox, said tubular and said shell elements cooperating to effect combustion of the pulverized coal within said combustion chamber under stoichiometric conditions resulting in reduced production of nitrogen oxides.
Claim 3
Dependent Claim
51 words
The combination of claim 1, further including means coupled to a source of fluid and disposed in operative relationship to said tubular and said shell elements for directing a swirling flow of fluid at the outlets of said tubular and said shell elements to maintain controlled turbulence of the combustion flame.
Claim 4
Dependent Claim
78 words
The combination of claim 2, wherein said means for directing the swirling flow includes: a tubular annulus disposed concentrically about said shell element and having an outlet disposed adjacent to the outlets of said tubular and said shell elements; coupling means connecting said annulus to a source of heated fluid; and a plurality of radially-extending guide members disposed on the outlet of said annulus for directing the flow of heated fluid from said annulus in a swirling configuration.
Claim 5
Dependent Claim
29 words
The combination of claim 3, further including a plenum chamber in fluid communication with said tubular annulus, and said coupling means is in fluid communication with said plenum chamber.
Claim 6
Dependent Claim
28 words
The combination of claim 1, wherein said flow control means includes a selectively-movable element for controlling the quantity flow of substantially turbulence-free combustion supporting gas from said windbox.
Claim 7
Dependent Claim
78 words
The combination of claim 1, wherein said flow control means includes: a duct disposed concentrically about said shell element for conducting combustion supporting gas to said combustion chamber; a pair of substantially-parallel, spaced members operatively connected to said duct and defining a flow passage between the spaced members; a tubular sleeve slidably disposed with respect to said spaced members and movable to vary the size of the flow passage; and means for selectively slidably moving said tubular sleeve.
Claim 8
Dependent Claim
57 words
The combination of claim 6, wherein said means for slidably moving said tubular sleeve includes: a plurality of spaced perforations disposed on said tubular sleeve; and screw means rotatably disposed in operative engagement with said perforations, whereby rotation of said screw means causes movement of said tubular sleeve axially relative to the longitudinal axis of said sleeve.
Claim 9
Dependent Claim
40 words
The combination of claim 1, wherein said means for introducing the heating fluid to said tubular element includes a first and a second conduit connected to said tubular element, said conduits introducing respectively a first and a second heated fluid.
Claim 10
Dependent Claim
26 words
The combination of claim 8, wherein said first heated fluid is a tempered, heated air and said second heated fluid is flue gas from said furnace.
Claim 11
Dependent Claim
86 words
The combination of claim 1, wherein said fine coal fraction comprises between 20% and 40% of the pulverized coal, and said first portion of transport fluid comprises approximately 90% to produce a relatively lean mixture of pulverized coal and fluid supplied to said shell member, said coarse coal fraction comprising the remainder of the pulverized coal, and said second portion of transport fluid comprising the remainder of transport fluid to produce a relatively rich mixture of pulverized coal and transport fluid supplied to said tubular member.
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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) | 1984-02-10 | 1984-08-11 | 1985-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-10 | 1988-08-11 | 1989-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-10 | 1992-08-11 | 1993-02-10 | $7700.00 | Window Closed / Lapsed |