Low nox burner with targeted gas injection

Abstract

A burner configured to produce a flame in a combustion zone is provided where the burner includes a combustion air conduit that provides combustion air to the combustion zone, a primary targeted gas conduit surrounded by the combustion air conduit that provides a targeted gas to the combustion zone, a secondary targeted gas conduit that provides additional targeted gas to the combustion zone, a primary fuel gas conduit surrounded by the targeted gas conduit that provides fuel gas to the combustion zone and a secondary fuel gas conduit that provides additional fuel gas to the combustion zone, where a portion of the fuel gas from at least one of the primary fuel gas conduit and the secondary fuel gas conduit is mixed with a portion of the targeted gas prior to mixing with the combustion air in the combustion zone.

What is claimed is: 
     
         1 . A burner configured to produce a flame in a combustion zone, the burner comprising:
 a combustion air conduit that provides combustion air to the combustion zone;   a primary targeted gas conduit surrounded by said combustion air conduit, said targeted gas conduit provides a targeted gas to the combustion zone;   a secondary targeted gas conduit that provides additional targeted gas to the combustion zone;   a primary fuel gas conduit surrounded by said targeted gas conduit, said primary fuel gas conduit provides fuel gas to the combustion zone;   a secondary fuel gas conduit that provides additional fuel gas to the combustion zone,   wherein a portion of the fuel gas from at least one of the primary fuel gas conduit and the secondary fuel gas conduit is mixed with a portion of the targeted gas prior to mixing with the combustion air in the combustion zone.   
     
     
         2 . The burner of  claim 1 , wherein an inlet of said fuel gas conduit draws in a flue gas from a combustion source. 
     
     
         3 . The burner of  claim 1 , wherein said combustion air conduit includes a closed end and openings at said closed end, the targeted gas flows across said closed end forming a fluid barrier between the combustion air and the fuel gas. 
     
     
         4 . The burner of  claim 1 , wherein said fuel gas conduit includes a closed end and openings at said closed end. 
     
     
         5 . The burner of  claim 1 , wherein a portion of the fuel gas is injected through an inlet to said combustion air conduit and mixes with a portion of the combustion air prior to the combustion zone. 
     
     
         6 . The burner of  claim 5 , wherein an amount greater than 0% to an amount equal to 95% of the targeted gas is mixed with the combustion air prior to entering said combustion air conduit with a balance of the targeted gas entering said targeted gas conduit. 
     
     
         7 . The burner of  claim 1 , wherein said targeted gas is a NOx reducing medium or a mixture of NOx reducing media. 
     
     
         8 . The burner of  claim 1 , wherein 100% of the fuel gas is supplied by the primary fuel gas conduit. 
     
     
         9 . The burner of  claim 1 , wherein 100% of the fuel gas is supplied by the secondary fuel gas conduit. 
     
     
         10 . The burner of  claim 1 , wherein 100% of the targeted gas is supplied by the primary targeted gas conduit. 
     
     
         11 . The burner of  claim 1 , wherein 100% of the targeted gas is supplied by the secondary targeted gas conduit. 
     
     
         12 . The burner of  claim 1 , further comprising a control system that controls the proportion of the fuel gas supplied by the primary fuel gas conduit and the secondary gas conduit and the proportion of the targeted gas that is supplied by the primary targeted gas conduit and the secondary targeted gas conduit. 
     
     
         13 . A process for reducing production of NOx gases at a burner, the process comprising:
 injecting a combustion air into a combustion zone;   injecting a targeted gas into the combustion zone via a primary targeted gas conduit;   injecting additional targeted gas into the combustion zone via a secondary targeted gas conduit;   injecting a fuel gas into the combustion zone via primary fuel gas conduit;   injecting additional fuel gas into the combustion zone via secondary fuel gas conduit;   wherein a portion of the fuel gas from at least one of the primary fuel gas conduit and the secondary fuel gas conduit is mixed with a portion of the targeted gas prior to mixing with the combustion air in the combustion zone.   
     
     
         14 . The process of  claim 13 , wherein 100% of the fuel gas is injected by the primary fuel gas conduit. 
     
     
         15 . The process of  claim 13 , wherein 100% of the fuel gas is injected by the secondary fuel gas conduit. 
     
     
         16 . The process of  claim 13 , wherein 100% of the targeted gas is injected by the primary targeted gas conduit. 
     
     
         17 . The process of  claim 13 , wherein 100% of the targeted gas is injected by the secondary targeted gas conduit. 
     
     
         18 . The process of  claim 13 , further comprising controlling the proportion of the fuel gas injected by the primary fuel gas conduit and the secondary gas conduit and the proportion of the targeted gas that is injected by the primary targeted gas conduit and the secondary targeted gas conduit.