Gas Injector

Abstract

The invention relates to a gas burner or gas injector having a diffuser, which by control actuations can be modified within wide limits as a free jet burner and is suitable in particular for industrial furnaces with regenerative air preheating, in particular those which have an air supply arranged separately from the fuel gas. The gas injector according to the invention has a gas supply pipe 1 and a mouth 2 , wherein the connection thereof forms a long diffuser 3 with a free jet opening angle, and is characterised in that the ratio of the diameter of the mouth 2 and the diameter of the gas supply pipe 1 is smaller than three. Preferably a central nozzle pipe 4 with a mouth 8 forming a free jet opening angle is arranged within the gas supply pipe 1 , forming an annular gap 9 for guiding a partial gas flow between the gas supply pipe 1 and the central nozzle pipe 4 , in such a way that the notional prolongation of the generatrix 7 of the central nozzle pipe mouth 8 goes into the generatrix of the long diffuser 3 . A closure and regulating device is provided for regulating the partial flows.

1 . A gas injector for nitrogen oxide-reducing firing of regeneratively heated industrial furnaces comprising a gas supply pipe and a mouth, wherein the connection thereof forms a long diffusers with a free jet opening angle, characterised in that the ratio of the diameter of the mouth and the diameter of the gas supply pipe is smaller than three. 
   
   
       2 .- 10 . (canceled) 
   
   
       11 . A gas injector as set forth in  claim 1  characterised in that a central nozzle pipe with a mouth forming a free jet opening angle is arranged within the gas supply pipe, forming an annular gap for guiding a partial gas flow between the gas supply pipe and the central nozzle pipe, in such a way that the notional prolongation of the generatrix of the central nozzle pipe mouth goes into the generatrix of the long diffuser. 
   
   
       12 . A gas injector as set forth in  claim 11  characterised in that a closure and regulating device for partial gas flow adjustment is arranged downstream of the central nozzle pipe. 
   
   
       13 . A gas injector as set forth in  claim 12  characterised in that the closure device comprises two separate valves which are arranged in an overall gas supply pipe and a secondary gas supply pipe which is branched therefrom and which directly charges the central nozzle pipe. 
   
   
       14 . A gas injector as set forth in  claim 11  characterised in that the closure device is in the form of a cone which is axially displaceable on the outer periphery of the central nozzle pipe and which co-operates with a conical surface of the inside wall of the gas supply pipe. 
   
   
       15 . A gas injector as set forth in  claim 12  characterised in that the closure device is arranged set back in opposite relationship to the flow direction from the mouth of the central nozzle pipe by more than five times the inside diameter of the central nozzle pipe. 
   
   
       16 . A gas injector as set forth in  claim 14  characterised in that the closure device is arranged set back in opposite relationship to the flow direction from the mouth of the central nozzle pipe by more than five times the inside diameter of the central nozzle pipe. 
   
   
       17 . A gas injector as set forth in  claim 1  characterised in that the mouth of the long diffuser is provided with a water-cooled ring at its outside periphery. 
   
   
       18 . A gas injector as set forth in  claim 17  characterised in that the water-cooled ring is arranged separately. 
   
   
       19 . A gas injector as set forth in  claim 17  characterised in that the water-cooled ring is rotatable about the axis of the gas injector. 
   
   
       20 . A gas injector as set forth in one or more of the preceding claims characterised in that the long diffuser and the ring are arranged together in a burner insert opening enlarging in opposite relationship to the gas flow direction, in such a way that the spacing between the water-cooled ring and the burner insert opening is at a minimum and the axis of the gas injector is rotatable about the center point of the mouth.