Oxy-Solid Fuel Burner

Abstract

A solid fuel/oxygen burner including a central oxygen conduit extending toward a tip end of the burner, an outer fuel conduit surrounding the oxygen conduit, an inner fuel conduit positioned between the oxygen conduit and the outer fuel conduit to form an inner annulus in conjunction with the oxygen conduit and an outer annulus in conjunction with the outer fuel conduit, the inner fuel conduit having an outlet end upstream of the tip end, a truncated conical divider within the outer fuel conduit surrounding the oxygen conduit downstream of the inner fuel conduit for dividing a fuel stream in the outer fuel conduit into an inner annular conical diffuser and an outer annular converging nozzle, and at least three radial guide vanes within the diffuser, wherein the outlet end of the inner fuel conduit is spaced apart from an inlet end of the divider by a distance, X.

1 . A solid fuel/oxygen burner comprising:
 a central oxygen conduit extending toward a tip end of the burner;   an outer fuel conduit surrounding the oxygen conduit and extending toward the tip end of the burner;   an inner fuel conduit positioned between the oxygen conduit and the outer fuel conduit to form an inner annulus between the oxygen conduit and the inner fuel conduit and an outer annulus between the inner fuel conduit and the outer fuel conduit, the inner fuel conduit having an outlet end upstream of the tip end of the burner;   a truncated conical divider positioned within the outer fuel conduit and surrounding the oxygen conduit downstream of the inner fuel conduit, the divider being configured to divide a fuel stream in the outer fuel conduit into an inner annular conical diffuser and an outer annular converging nozzle; and   at least three radial guide vanes positioned within the diffuser;   wherein the outlet end of the inner fuel conduit is spaced apart from an inlet end of the divider by a distance, X.   
     
     
         2 . The burner of  claim 1 ,
 wherein the outlet end of the inner annulus has a height, h 1 ;   wherein the inlet end of the annular conical diffuser has a height, h 2 ; and   wherein h 1  is greater than h 2 .   
     
     
         3 . The burner of  claim 1 , further comprising:
 a bluff body positioned within the diffuser, the bluff body having a leading edge and a trailing end adjacent to an upstream end of the radial guide vanes.   
     
     
         4 . The burner of  claim 1 ,
 wherein the divider includes a leading edge oriented substantially parallel to the outer fuel conduit.   
     
     
         5 . The burner of  claim 1 , further comprising:
 an outer oxygen conduit surrounding the outer fuel conduit and extending toward the tip end of the burner.   
     
     
         6 . The burner of  claim 5 , further comprising
 a secondary oxygen conduit spaced apart from the outer fuel conduit and extending toward the tip end of the burner.   
     
     
         7 . The burner of  claim 1 , further comprising:
 the outer annulus forming a tertiary oxygen conduit.   
     
     
         8 . The burner of  claim 7 , further comprising
 a secondary oxygen conduit spaced apart from the outer fuel conduit and extending toward the tip end of the burner.   
     
     
         9 . A method of combusting a pulverized solid fuel with oxygen, the method comprising:
 flowing a center oxygen stream through a central conduit extending toward a tip end of a burner, the central oxygen conduit being surrounded by an outer fuel conduit extending toward the tip end of the burner;   flowing a fuel stream of pulverized fuel in a transport gas through an inner annulus formed by an inner fuel conduit positioned between the oxygen conduit and the outer fuel conduit;   causing the fuel stream to exit the inner annulus at an outlet end of the inner fuel conduit positioned upstream of the tip end of the burner;   dividing the fuel stream into two streams including an inner annular conical diffuser stream formed by a truncated conical divider having an inlet end positioned at a distance, X, downstream of the outlet end of the inner fuel conduit, and an outer annular converging nozzle stream formed between the divider and the outer fuel conduit, wherein the inner diffuser stream decelerates and the outer nozzle stream accelerates; and   flowing the inner diffuser stream across at least three radial guide vanes positioned within the divider.   
     
     
         10 . The method of  claim 9 ,
 wherein the outlet end of the inner annulus has a height, h 1 ;   wherein the inlet end of the annular conical diffuser has a height, h 2 ; and   wherein h 1  is greater than h 2 .   
     
     
         11 . The method of  claim 9 , further comprising:
 flowing the inner diffuser stream across a bluff body positioned with a trailing end of the bluff body adjacent to an upstream end of the radial guide vanes.   
     
     
         12 . The method of  claim 9 ,
 wherein the divider includes a leading edge oriented substantially parallel to the outer fuel conduit.   
     
     
         13 . The method of  claim 9 , further comprising:
 flowing a stream of outer oxygen through an annular oxygen passage bounded by an outer oxygen conduit surrounding the outer fuel conduit and extending toward the tip end of the burner.   
     
     
         14 . The method of  claim 13 , further comprising:
 flowing a stream of secondary oxygen through a secondary oxygen conduit spaced apart from the outer oxygen conduit and extending to the tip end of the burner.   
     
     
         15 . The method of  claim 9 , wherein the burner is operated with less than the stoichiometric amount of oxygen, with a stoichiometric ratio from about 0.05 to about 0.5. 
     
     
         16 . A regenerative furnace comprising:
 a burner block having at least one firing port mounted in a sidewall of the furnace; and   one or more solid fuel/oxygen burners positioned near an edge of the at least one firing port, the burner comprising:
 a central oxygen conduit extending toward a tip end of the burner; 
 an outer fuel conduit surrounding the oxygen conduit and extending toward the tip end of the burner; 
 an inner fuel conduit positioned between the oxygen conduit and the outer fuel conduit to form an inner annulus between the oxygen conduit and the inner fuel conduit and an outer annulus between the inner fuel conduit and the outer fuel conduit, the inner fuel conduit having an outlet end upstream of the tip end of the burner; 
 a truncated conical divider positioned within the outer fuel conduit and surrounding the oxygen conduit downstream of the inner fuel conduit, the divider being configured to divide a fuel stream in the outer fuel conduit into an inner annular conical diffuser and an outer annular converging nozzle; and 
 at least three radial guide vanes positioned within the diffuser; 
 wherein the outlet end of the inner fuel conduit is spaced apart from an inlet end of the divider by a distance, X; 
 wherein in an under-port arrangement, the one or more burners are positioned beneath the at least one firing port in an under-port arrangement; and 
 wherein in a side-port arrangement, the one or more burners are positioned along a side of the at least one firing port.