Apparatus and method for minimizing smoke formation in a flaring stack

Abstract

An apparatus and method for minimizing smoke formation in the operation of a flaring stack. The apparatus includes a generally annular gas deflector having an outer surface for deflecting the waste gas therealong. A plurality of lobes extend radially from the deflector to provide improved mixing between the waste gas, steam, and combustion air during combustion to reduce smoke formation.

1 . A method for combusting a waste gas to reduce the formation of smoke, the method comprising:
 passing steam along an outer surface of a generally annular gas deflector including a plurality of lobes extending radially outwardly from the gas deflector;   passing the waste gas along the outer surface of the gas deflector including over the plurality of lobes;   drawing ambient air toward the outer surface for mixing with the waste gas and steam; and   igniting the waste gas.   
     
     
         2 . The method of  claim 1 , wherein passing the waste gas along the outer surface includes passing the waste gas over a plurality of circumferentially spaced generally vertical ribs extending radially from the outer surface. 
     
     
         3 . The method of  claim 2 , wherein passing the steam along the outer surface includes distributing the steam radially inwardly of the waste gas. 
     
     
         4 . The method of  claim 3 , wherein distributing the steam includes distributing the steam from a generally annular steam distributor outlet positioned radially inwardly from a generally annular waste gas outlet. 
     
     
         5 . The method of  claim 3 , wherein distributing the steam includes forming a layer of steam over at least a portion of the outer surface, and
 passing the waste gas over the layer of steam to mix with the steam.   
     
     
         6 . The method of  claim 2 , wherein distributing the steam includes distributing the steam from a plurality of openings arranged circumferentially about the gas deflector and generally aligned with the ribs. 
     
     
         7 . The method of  claim 2 , wherein distributing the steam includes distributing the steam from a plurality of openings arranged circumferentially about the gas deflector and generally aligned with channels between the ribs. 
     
     
         8 . The method of  claim 2 , wherein passing the steam along the outer surface includes passing the steam over a Coanda surface of a generally tulip-shaped Coanda bowl. 
     
     
         9 . The method of  claim 8 , wherein passing the steam over the Coanda surface includes passing the steam over an unribbed convex portion of the Coanda surface and then over a ribbed portion of the Coanda surface. 
     
     
         10 . The method of  claim 8 , wherein passing the steam along the Coanda surface includes passing the steam over a ribbed convex portion of the Coanda surface. 
     
     
         11 . The method of  claim 2 , wherein passing the steam along the outer surface includes passing the steam along inclined sidewalls extending from channels between the ribs to rib upper portions. 
     
     
         12 . A method for combusting a waste gas to reduce the formation of smoke, the method comprising:
 passing steam through an annular outlet along an outer surface of a generally annular gas deflector including a plurality of lobes extending radially from an outer surface thereof   passing the waste gas along the outer surface of the gas deflector including over the plurality of lobes;   drawing ambient air toward the outer surface for mixing with the waste gas and steam; and   igniting the waste gas.   
     
     
         13 . The method of  claim 12 , wherein passing the steam through the annular outlet includes passing the steam to a steam chamber and distributing the steam through a plurality of openings of the steam chamber toward the outer surface. 
     
     
         14 . The method of  claim 13 , wherein passing the steam through the plurality of openings includes passing the steam through openings formed between an upper notched portion of the steam chamber and a lower portion of the gas distributor. 
     
     
         15 . The method of  claim 13 , wherein passing the steam through the plurality of openings includes passing the steam through a plurality of apertures in an upper portion of the steam chamber. 
     
     
         16 . The method of  claim 13 , wherein passing the waste gas along the outer surface includes passing the waste gas through a generally annular outlet of a support arm radially outwardly of the steam chamber. 
     
     
         17 . The method of  claim 16 , wherein distributing the steam includes forming a layer of steam over at least a portion of the outer surface, and
 passing the waste gas along the layer of steam to mix with the steam.   
     
     
         18 . The method of  claim 12 , further comprising passing the steam through a steam passageway of a support arm supporting the gas deflector and passing the waste gas through an annular waste gas passageway of the support arm formed about the steam passageway.