Low-nox gas injector

Abstract

The invention relates to: a combustion process, especially for melting glass, in which a flame is created by gaseous fuel, characterized in that several regularly spaced peripheral low-pressure gas jets converge on a central high-pressure gas jet; an injector for implementing this process; a burner comprising one or more such injectors; and a furnace comprising at least one such burner.

1 . A combustion process comprising creating a flame with gaseous fuel, wherein at least two regularly spaced peripheral low-pressure gas jets converge on a central high-pressure gas jet. 
     
     
         2 . The process as claimed in  claim 1 , wherein 70 to 90%, of the calorific power stems from the low-pressure gas. 
     
     
         3 . The process as claimed in  claim 1 , wherein the angle of convergence of the peripheral low-pressure gas jets toward the central high-pressure gas jet is between 4° and 10°. 
     
     
         4 . The process as claimed in  claim 1 , wherein the number of peripheral low-pressure gas jets is between 4 and 16. 
     
     
         5 . The process as claimed in  claim 1 , wherein all peripheral low-pressure gas jets present have the same cross section, flow route and angle of convergence toward the axis of the central high-pressure gas jet. 
     
     
         6 . An injector for implementing the process as claimed in  claim 1 , comprising a high-pressure gas feed duct circumscribed in a coaxial low-pressure gas feed duct, the outlet of which is completely obstructed by a flat ring provided with holes of identical cross section, these being regularly spaced around the axis of said feed ducts and all converging at the same angle on said axis. 
     
     
         7 . The injector as claimed in  claim 6 , wherein the cross sections of the holes have circular perimeters. 
     
     
         8 . A burner comprising one or more injectors as claimed in  claim 6 . 
     
     
         9 . A furnace comprising at least one burner as claimed in  claim 8 . 
     
     
         10 . (canceled) 
     
     
         11 . A method of reducing the amount of NO x  emitted during combustion of fuel, comprising:
 generating a flame by combusting fuel; and   converging the flow of fuel from at least two low-pressure gas jets onto the flow of fuel from a central high-pressure gas jet.   
     
     
         12 . The process as claimed in  claim 1 , wherein 75 to 85% of the calorific power stems from the low-pressure gas. 
     
     
         13 . The process as claimed in  claim 1 , wherein the angle of convergence of the peripheral low-pressure gas jets toward the central high-pressure gas jet is between 5° and 8. 
     
     
         14 . The process as claimed in  claim 1 , wherein the number of peripheral low-pressure gas jets is between 8 and 12.