Air-Gas Pilot Burner that can Operate with Oxygen

Abstract

A system includes at least one pilot burner and one more powerful main burner. The pilot burner includes at least a first tube open at an end and including at least a first feedline capable of injecting a combustible gas into the first tube. The pilot burner further includes at least a second tube open at an end and including at least a third feedline capable of injecting an oxygen-rich gas into the second tube. The pilot burner further includes at least a second feedline capable of feeding the first tube with air.

1 . A system comprising at least one pilot burner and at least one more powerful main burner, said pilot burner comprising:
 at least a first tube open at an end and including at least a first feedline capable of injecting a combustible gas into said first tube; and   at least a second tube open at an end and including at least a third feedline capable of injecting an oxygen-rich gas into said second tube,   
     characterized in that said pilot burner further comprises at least a second feedline capable of feeding said first tube with air. 
   
   
       2 . The system of  claim 1 , wherein said pilot burner further comprises:
 electrodes capable of producing at least one electric arc or a spark in order to ignite said pilot burner; and   a device designed for and capable of controlling the presence of a flame emanating from said pilot burner.   
   
   
       3 . The system of  claim 1 , wherein:
 said first tube is at least partially located inside said second tube; or   said second tube is at least partially located inside said first tube.   
   
   
       4 . The system of  claim 1 , wherein at least one portion of said first tube and at least one portion of said second tube have gas flow bores of constant area. 
   
   
       5 . The system of  claim 4 , wherein said portions of said tubes having gas flow bores of constant area have concentric circular cross sections. 
   
   
       6 . The system of  claim 1 , wherein a ratio of the minimum area of the bore for flow of said combustible gas close to the outlet of said first tube to the minimum area of the bore of said oxygen-rich gas close to the outlet of said second tube is not less than 0.15 but does not exceed 5.5. 
   
   
       7 . The system of  claim 1 , wherein:
 said first tube comprises a convergent portion as outlet, which converges in the flow direction of said combustible gas; and/or   said second tube comprises a convergent portion as outlet, which converges in the flow direction of said oxygen-rich gas; and/or   said second tube comprises elements intended to reduce the bore of said second tube.   
   
   
       8 . A combustion installation using an oxidizer gas, comprising:
 at least one oxy-fuel combustion boiler or furnace designed for and capable of operating in oxy-fuel combustion mode with an oxygen-rich gas as oxidizer or in degraded mode with air used as oxidizer;   at least one air separation unit capable of delivering an oxygen-rich gas; and   at least one compressed-air feedline or at least one air compressor, characterized in that:   said boiler or furnace comprises at least one system according to  claim 1 ;   said oxygen-rich gas feedline of said pilot burner is fluidically connected to said air separation unit so as to be able to receive oxygen-rich gas produced by said air separation unit; and   said air feedline of said pilot burner is fluidically connected to said at least one compressed-air feedline or to said at least one air compressor.   
   
   
       9 . A combustion process employing at least one oxy-fuel combustion boiler or furnace comprising one or more main burners designed for and capable of operating in oxy-fuel combustion mode with an oxygen-rich gas used as oxidizer or in degraded mode with air used as oxidizer, an oxygen-rich gas source comprising at least one air separation unit capable of delivering an oxygen-rich gas, and an air source comprising at least one compressed-air feedline or at least one air compressor, said boiler or furnace comprising at least one pilot burner as defined in  claim 1 , said method comprising the step of:
 a) air, as oxidizer, coming from said air source, is injected into the main burners of said boiler or furnace and into said air feedline of said pilot burner, wherein said oxygen-rich gas feedline of said pilot burner does not introduce oxygen-rich gas into said pilot burner.   
   
   
       10 . The process of  claim 9 , further comprising the step of:
 b) an oxygen-rich gas, as oxidizer, coming from said oxygen-rich gas source, is injected into the main burners of said boiler or furnace and into said oxygen-rich gas feedline of said pilot burner, wherein said air feedline of said pilot burner does not introduce air into said pilot burner and said steps a) and b) may be performed in any order.   
   
   
       11 . The process of  claim 9 , further comprising the steps of:
 c) a first fuel of gaseous type is injected into said combustible gas feedline of said pilot burner; and   d) at least one main burner of said boiler or furnace is fed with a second fuel.