Furnaces – Including fluid fuel burner – Powdered solid fuel
Patent
1998-04-20
2000-11-28
Lazarus, Ira S.
Furnaces
Including fluid fuel burner
Powdered solid fuel
110104B, 110265, 431181, 431182, 431 8, F23C 110, F23D 100
Patent
active
061520519
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a combustion burner.
BACKGROUND OF THE INVENTION
A burner of this type comprises a mixture nozzle, and a gas supply nozzle surrounding this mixture nozzle.
In a pulverized coal burner disclosed in JP-A-63-87508, an impeller for swirling an air-fuel mixture is provided within a mixture nozzle. The swirled mixture from an outlet of the mixture nozzle is rapidly diffused within a furnace, and is mixed with secondary air and tertiary air, supplied from a gas supply nozzle, in the vicinity of the outlet of the mixture nozzle. Therefore, a reduction area is not sufficiently formed, and a flame does not spread in the furnace. As a result, a part of fine pulverized coal remains unburned, and the production of NOx can not be suppressed.
In a pulverized coal burner disclosed in JP-A-60-200008, a throat portion is provided within a mixture nozzle, and an outlet of the mixture nozzle is flared. In this burner, as in the above-mentioned burner, an air-fuel mixture from an outlet of the mixture nozzle is rapidly diffused within a furnace, and is mixed with secondary air and tertiary air, supplied from a gas supply nozzle, in the vicinity of the outlet of the mixture nozzle. As a result, a part of fine pulverized coal remains unburned, and the production of NOx can not be suppressed.
BRIEF SUMMARY OF THE INVENTION
It is an object of this invention to provide a combustion burner which solves these problems, and can achieve low-NOx combustion.
To this end, according to one aspect of the present invention, there is provided a combustion burner comprising: a mixture nozzle which extends toward an interior of a furnace, and defines a mixture passage through which a mixture containing powdered solid fuel and gas for transferring the solid fuel flows, and a distal end portion of which mixture nozzle is flared so that a flow passage area of the mixture passage increases progressively in a direction of flow of the mixture; a gas supply nozzle radially surrounding the mixture nozzle and defining between the gas supply nozzle and the mixture nozzle a gas passage through which combustion oxygen-containing gas flows towards the furnace; and guide means provided within the mixture nozzle at a position upstream of the flared portion of the mixture nozzle with respect to a flow of the mixture so as to make the mixture flow straightly along an inner peripheral surface of the flared portion of the mixture nozzle.
According to another aspect of the present invention, there is provided a combustion burner comprising: a mixture nozzle extending towards an interior of a furnace, and defining a mixture passage through which a mixture containing powdered solid fuel and gas for transferring the solid fuel flows, and a distal end portion of which mixture nozzle is flared so that a flow passage area of the mixture passage increases progressively in a direction of flow of the mixture; a gas supply nozzle radially surrounding the mixture nozzle, and defining between the gas supply nozzle and the mixture nozzle a gas passage, through which combustion oxygen-containing gas flows towards the furnace, and a gas jet nozzle through which gas is injected radial inwardly towards the mixture flowed into the furnace from the distal end of the mixture nozzle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of an embodiment of a burner of the present invention;
FIG. 2 is a cross-sectional view of a furnace of a boiler using the burners of FIG. 1, showing a condition of a flame in the furnace;
FIG. 3 is a cross-sectional view taken along the line III--III of FIG. 2;
FIG. 4 is a cross-sectional view showing the condition of the flame in the furnace;
FIG. 5 is a cross-sectional view showing a flow of a mixture and a flow of combustion air in the burner;
FIG. 6 is a cross-sectional view showing a condition of a flame in a furnace using a conventional burner;
FIG. 7 is a cross-sectional view of the furnace of a boiler using the conventional burners, showing the condition of the flame in the furna
REFERENCES:
patent: 4630554 (1986-12-01), Sayler et al.
patent: 4838185 (1989-06-01), Flament
patent: 5090339 (1992-02-01), Okiura et al.
patent: 5199355 (1993-04-01), Larue
patent: 5231937 (1993-08-01), Kobayashi et al.
patent: 5263426 (1993-11-01), Morita et al.
patent: 5567141 (1996-10-01), Joshi et al.
patent: 5685242 (1997-11-01), Narato et al.
patent: 5832847 (1998-11-01), Leisse et al.
patent: 5842426 (1998-12-01), Ohta et al.
Jimbo Tadashi
Kiyama Kenji
Kuramashi Koji
Mori Miki
Morita Shigeki
Babcock-Hitachi Kabushiki Kaisha
Ciric Ljiljana V.
Lazarus Ira S.
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