Patent ID: 7025590

Claim:
In a radiant wall furnace having walls, a floor and a burner configuration utilizing rows or columns or both of multiple radiant wall burners having longitudinal axes substantially perpendicular and attached to a wall of the furnace, each directing a combustible fuel gas-excess air mixture in a direction radially outward relative to the longitudinal axis thereof into a combustion zone adjacent a burner tile, the improvement which comprises: an array of secondary fuel gas nozzles for injecting secondary fuel gas into the furnace that mixes with flue gases in the furnace and combusts with excess air, lowers the temperature of the burning fuel gas and reduces the formation of NO X , and means for introducing secondary fuel gas into said secondary fuel gas nozzles, said secondary fuel gas nozzles being located separate and remote from the radiant wall burners such that the secondary fuel gas is not encapsulated or surrounded by the fuel gas-air mixture from the radiant wall burners thereby allowing secondary fuel gas to mix with flue gases in the furnace prior to mixing with the fuel gas-air mixture.