초록 ▼

This burner is so designed as to be capable of operating in a stable manner with no risk of explosion with pure oxygen or air highly enriched with oxygen as the reactant. In one embodiment, a stream of oxygen is delivered through a central tube 4A which terminates in a divergent annular diffuser 30.

This burner is so designed as to be capable of operating in a stable manner with no risk of explosion with pure oxygen or air highly enriched with oxygen as the reactant. In one embodiment, a stream of oxygen is delivered through a central tube 4A which terminates in a divergent annular diffuser 30. A mixture of air and pulverized coal is delivered in an intermediate ring 15 around this diffuser and an annular stream of whirling oxygen is delivered in an outer ring 16. Application in indirect heating furnaces, furnaces in which slag exists and cement-making furnaces and in cases where special atmospheres (for example reducing atmospheres) are desired.

대표청구항 ▼

1. A burner assembly for pulverized coal having a self-maintained combustion, comprising: a first source of a mixture of air and coal; a second source of substantially pure oxygen; a burner body comprising a free supply passageway for supplying said mixture of air and coal, means connecting said fre

1. A burner assembly for pulverized coal having a self-maintained combustion, comprising: a first source of a mixture of air and coal; a second source of substantially pure oxygen; a burner body comprising a free supply passageway for supplying said mixture of air and coal, means connecting said free passageway to said first source, a first supply passageway for supplying substantially pure oxygen concentrically surrounding the free passageway, supply means for supplying substantially pure oxygen radially inwardly with respect to said first supply passageway, means connecting said first supply passageway and said supply means to said second source, said free and first supply passageways having respective downstream discharge ends at which ends they open onto a common transverse plane, said first supply passageway being provided with a device for rotating the gas conveyed by said first supply passageway; and a divergent cowl provided with cooling means and extending from said plane, said cowl having upstream fastening means for removably securing said cowl to said burner body and downstream fastening means for the removable mounting of the burner assembly, said first and second sources supplying said mixture and said oxygen in respective amounts having a coal-to-oxygen ratio which is substantially stoichiometric with respect to the combustion reaction C+O 2 →CO 2 . 2. A burner according to claim 1, wherein said supply means comprise a second supply passageway which is concentrically surrounded by said free supply passageway and has a downstream end at which end the second supply passageway also opens onto said transverse plane. 3. A burner according to claim 2, wherein said second supply passageway is an annular passageway provided with a device for rotating the gas conveyed by said second supply passageway. 4. A burner according to claim 1, wherein said free supply passageway is a central passageway having an outlet end, said supply means comprising a centripetal injection device for substantially pure oxygen in a part of the central passageway adjacent to said outlet end of the central passageway. 5. A burner according to claim 4, wherein the injection device comprises a plurality of injection nozzles inclined in a circumferential direction relative to a radial direction. 6. A burner according to claim 5, wherein said nozzles are also inclined in a longitudinal direction toward the outlet end of the central passageway. 7. A burner according to claim 4, wherein the injection device is disposed at the outlet end of the first supply passageway and is supplied with substantially pure oxygen by the first supply passageway, the first supply passageway being provided with throttling means. 8. A burner for pulverized coal having a self-maintained combustion, comprising a free supply passageway for supplying a mixture of air and coal, a first supply passageway for supplying oxygen-enriched air or pure oxygen concentrically surrounding the free passageway, a second supply passageway concentrically surrounded by said free supply passageway for supplying oxygen-enriched air or pure oxygen radially inwardly with respect to said first supply passageway, said free, first and second supply passageways having downstream ends at which ends they open onto a common transverse plane, and wherein said second supply passageway is a central passageway having a divergent annular diffuser that terminates the central passageway, said diffuser being in the form of a frustoconical element whose downstream end is crowned, and a divergent cowl provided with cooling means and extending from said common transverse plane. 9. A burner for pulverized coal having a self-maintained combustion, comprising a central passageway for supplying a mixture of air and coal, said central passageway having an outlet end, a first oxygen supply passageway for supplying substantially pure oxygen concentrically surrounding the central passageway, a centripetal injection device for supplying substantially pure oxygen to a part of the central passageway adjacent to said outlet end thereof, a second oxygen supply passageway having an inlet for receiving substantially pure oxygen, and having a closed end, the injection device being disposed in the vicinity of the closed end of the second oxygen supply passageway and the second oxygen supply passageway being surrounded by the first oxygen supply passageway, said central and first oxygen supply passageways having downstream ends at which ends they open onto a common transverse plane, and a divergent cowl provided with cooling means and extending from said plane.