Solid Fuel Burner

Abstract

Burner for conveyor gas propelled particulate solid fuel, said burner comprising a burner block and an injector assembly, the injector assembly being at least partially surrounded by an injector passage of the burner block, the injector assembly comprising an inner oxygen supply pipe surrounding a fuel injector, which in turn surrounds an oxygen injector, each having a downstream end on the side of the passage outlet, the inner oxygen supply pipe having a lateral surface onto which are mounted a set of lateral primary oxygen nozzles for the injection of lateral jets of primary oxygen into the fuel injector with an injection orientation which follows a same sense of rotation around the longitudinal direction and which is directed towards the downstream end of the fuel injector, said lateral primary oxygen nozzles being positioned at a number of different distances from the downstream end of the fuel injector.

1 - 15 . (canceled) 
     
     
         16 . A burner comprising:
 a burner block,   the block having an inlet face and an outlet face and an injector passage extending in a longitudinal direction D 1  from a passage inlet in the inlet face to a passage outlet in the outlet face; and   an injector assembly being at least partially surrounded by the injector passage and comprising an inner oxygen supply pipe, a fuel injector and an oxygen injector, each having a downstream end on the side of the passage outlet, wherein:
 the fuel injector has a fuel injection nozzle at its downstream end for injecting particulate solid fuel propelled by a conveyor gas towards the passage outlet; 
 the fuel injector surrounds the inner oxygen supply pipe in the vicinity of the downstream end of the inner oxygen supply pipe; 
 the oxygen injector has an oxygen injector nozzle at its downstream end for injecting secondary oxygen towards the passage outlet; 
 the oxygen injector surrounds the fuel injector in the vicinity of the downstream end of the oxygen injector; 
 the inner oxygen supply pipe has a lateral surface onto which are mounted a set of lateral primary oxygen nozzles for the injection of lateral jets of primary oxygen into the fuel injector; 
 said lateral primary oxygen nozzles are positioned at a number of different distances, measured in the longitudinal direction D 1 , from the downstream end of the fuel injector; and 
 said lateral primary oxygen nozzles have an injection opening oriented for the injection of said lateral jets of primary oxygen with an injection orientation which follows a same sense of rotation around longitudinal direction D 1  and which is directed towards the downstream end of the fuel injector. 
   
     
     
         17 . The burner of  claim 16 , wherein the lateral primary oxygen nozzles have an injection opening oriented for the injection of a lateral jet of primary oxygen with an injection orientation substantially tangential to the lateral surface of the inner oxygen supply pipe. 
     
     
         18 . The burner of  claim 16 , further comprising a connector that detachably connects the inner oxygen supply pipe to the inside of the fuel injector. 
     
     
         19 . The burner of  claim 18 , the connector allows the inner oxygen supply pipe to be removed from the inside of the fuel injector on the side of the inlet face of the block. 
     
     
         20 . The burner of  claim 19 , further comprising a fuel supply pipe for supplying particulate solid fuel propelled by conveyor gas to the fuel injector, said fuel supply pipe defining an elbow upstream of the fuel injector, the burner comprising a branch pipe in line with the fuel injector and mounted on the fuel supply pipe in said elbow and through which the inner oxygen supply pipe can be mounted into the fuel injector and can be removed from the fuel injector. 
     
     
         21 . The burner of  claim 16 , wherein openings or perforations are formed in the lateral wall of the inner oxygen supply pipe and into which the lateral primary oxygen nozzles are fitted with a desired orientation. 
     
     
         22 . The burner of  claim 16 , wherein said lateral primary oxygen nozzles are positioned at a number of different radial angles (θ 1 , θ 2 , θ 3 , θ 4 ) around the lateral surface of the inner oxygen supply pipe. 
     
     
         23 . The burner of  claim 16 , wherein the inner oxygen supply pipe further comprises a terminal primary oxygen nozzle at its downstream end for injecting primary oxygen. 
     
     
         24 . The burner of  claim 23 , wherein the oxygen supply pipe comprises:
 a central lance terminating in the terminal primary oxygen nozzle which is in fluid connection with the central lance; and   a surrounding annular passage between the lateral surface of the inner oxygen supply pipe and the central lance, said surrounding annular passage being in fluid connection with the lateral primary oxygen nozzles.   
     
     
         25 . The burner of  claim 24 , further comprising an oxygen distributor in separate fluid connection with the central lance and with the surrounding annular passage, said oxygen distributor being:
 adapted and configured to be connected to an oxygen source; and   adapted and configured to control an allocation of the primary oxygen flow between the central lance and into the surrounding annular passage.   
     
     
         26 . The burner of  claim 16 , wherein the injector passage has a precombustion section proximate the passage outlet that is wider than the injector passage. 
     
     
         27 . A furnace comprising furnace walls defining a combustion chamber and at least one of the burner of  claim 16 , the burner being mounted in one of the furnace walls so that the outlet face of the burner block faces the combustion chamber and so that the inlet face of the burner block is accessible from outside the combustion chamber. 
     
     
         28 . A furnace comprising furnace walls defining a combustion chamber and at least one burner of  claim 16 , the burner being mounted in one of the furnace walls so that the outlet face of the burner block faces the combustion chamber and so that the inlet face of the burner block is accessible from outside the combustion chamber, wherein the outlet face of the burner block is recessed with respect to the surface of said wall facing the combustion chamber thereby creating a wider precombustion section between the outlet face of the burner block and said surface of the wall. 
     
     
         29 . A method of combustion, comprising use of the burner of  claim 16  to combust particulate solid fuel in a combustion zone of a furnace to produce heat therein. 
     
     
         30 . The method according to  claim 28 , wherein the fuel is pulverized coal.