Claims
- 1. Burner means for the firing of pulverized solvent refined coal fuel or the like comprising:
- a burner tube having a fuel inlet end and a discharge end,
- means for mounting said burner tube on a furnace wall with the discharge end thereof arranged to discharge the solvent refined coal into the furnace chamber for burning thereof,
- a diffuser centrally located within said burner tube and extending axially along the length thereof to an end location inwardly of and adjacent to said burner tube discharge end,
- said diffuser and burner tube defining an annular burner passage extending from said fuel inlet end of said burner tube to said discharge end thereof,
- inlet means for delivering a mixture of primary air and fuel to the fuel inlet end of said burner tube for flow thereof uniformly through said burner passage,
- said diffuser having an outwardly diverging conical portion at said discharge end for diverting the flow of the primary air-fuel mixture outwardly at an angle to the longitudinal axis of said burner tube, said conical portion extending from a location beyond said discharge end to a location inwardly of said discharge end,
- said conical portion of said diffuser and said burner tube discharge end defining a single annular burner orifice through which said mixture of primary air and fuel passes, the diameter of said conical portion of said diffuser being such that the cross-sectional area of said annular burner orifice is less than the cross-sectional area of said annular burner passage,
- said conical portion of said diffuser having an outer diameter at its tip approximately the same as the inner diameter of said burner tube so as to shield the discharge end of said burner tube and the fuel passing therethrough from heat radiation from the burner flame,
- means for water-cooling said diffuser along the length thereof adjacent said burner tube and at the conical portion thereof,
- means for supplying a flow of secondary air for mixture with said primary air-fuel mixture,
- means providing a water-cooled annulus eternally of said burner tube between said burner passage for the primary air-fuel mixture flow and said secondary air flow, and
- means supplying a mixture of primary air and pulverized solvent refined coal fuel to said inlet means so as to maintain the velocity of said primary air-fuel mixture passing through said burner orifice in the range of about 125-400 ft/sec.
- 2. Burner means according to claim 1 wherein said primary air-fuel supply means is operated at pressure and flow conditions so that primary air-fuel mixture velocity is maintained to be greater than 95 ft/sec throughout the fuel transport system.
- 3. Burner means according to claim 2 wherein said inlet means is constructed and arranged to deliver said primary air-fuel mixture tangentially into the fuel inlet end of said burner tube so that said mixture swirls around said burner passage as it flows therethrough.
- 4. Burner means according to claim 1 wherein said inlet means is constructed and arranged to deliver said primary air-fuel mixture tangentially into the fuel inlet end of said burner tube so that said mixture swirls around said burner passage as it flows therethrough.
- 5. Burner means according to claim 4 including a diffusion swirler mounted in said burner passage and including vanes oriented at an angle to the burner axis in the direction of flow to cause said primary air-fuel mixture to swirl in a cocurrent direction with said tangential inlet swirl of said mixture.
- 6. Burner means according to claim 5 wherein said secondary air supply means is constructed and arranged to introduce the secondary air into the furnace in a swirling flow, said swirling flow of said diffusion swirler being cocurrent with said swirling flow of said secondary air.
- 7. Burner means according to claim 5 wherein said secondary air supply means includes a windbox defining a windbox chamber surrounding said burner tube and having a discharge opening around said discharge end of said burner tube, said watercooled annulus being located between said windbox chamber and said burner passage.
- 8. Burner means according to claim 5 wherein said diffusion swirler has said vanes thereof arranged at approximately a thirty degree angle to the direction of flow.
- 9. Burner means according to claim 8 wherein said diffusion swirler is located with its front end about two burner tube diameters back from said conical portion.
- 10. Burner means according to claim 5 wherein said primary air-fuel supply means is operated at pressure and flow conditions so that the primary air-fuel mixture velocity is maintained to be greater that 95 ft/sec throughout the fuel transport system.
- 11. Burner means according to claim 1 wherein said conical portion is arranged to divert the flow of the primary air-fuel mixture outwardly of an angle at about thirty degrees to the longitudinal axis of said burner tube.
- 12. Burner means according to claim 1 wherein said means for water-cooling said diffuser includes a pair of concentric tubes internally of said diffuser forming inner and outer annular passages for the cooling water, one of said concentric tubes having a cone-shaped tip located at said conical portion around which said cooling water flows.
- 13. Burner means according to claim 1 wherein said water-cooled annulus is provided by a tubular jacket around the exterior of said burner tube and is divided into two flow portions by axially extending dividers.
- 14. Burner means according to claim 13 including a baffle located in the end of said jacket to define an end chamber adjacent said discharge end of said burner tube, said end chamber having ports therein and providing flow communication between said two flow portions of said water-cooled annulus.
- 15. Burner means according to claim 14 wherein the cooling water flow through said end chamber is maintained at a high velocity turbulent flow.
- 16. Burner means according to claim 1 wherein said diffuser includes a central axial passage which at one end terminates at the center of said conical portion, said central axial passage being in communication with means to supply air to said central axial passage to be discharged at the center of said conical portion of said diffuser.
BACKGROUND OF THE INVENTION
This invention relates generally to the art of firing pulverized solvent refined coal in a burner for a boiler or the like.
The Government of the United States of America has rights in this invention pursuant to Contract No. DE-AC05080-R03054 (as modified) awarded by the U.S. Department of Energy.
US Referenced Citations (11)