BigPatents India

A staged oxy-fuel burner for producing a generally flat rich overlying a highly radiative fuel flame, the burner having a fuel passage terminating in a nozzle,the fuel passage and nozzle having a generally elongated cross-section , a housing of complementary shape surrounding the fuel passage, so that when fuel is introduced into the fuel passage and an oxidizer is introduced into the passage defined by a space between the housing and the fuel passage a generally flat rich flame is produced at the nozzle end of the fuel conduit and a staging nozzle for introducing oxidizer underneath and in a shape complementary to said fuel rich flame to produce a highly radiative fuel lean flame under said fuel rich flame. A precombustor having a cross-sectional shape complementary to that of flame end of the burner can be disposed on the flame end of the burner housing the precombustor having a nozzle underneath the flame end to introduce oxidizer underneath the fuel rich flame existing the precombustor. The invention also provides a staged oxy-fuel combustor system and a method of producing a low NOx-fuel flame for heating a furnace to an elevated temperature.