Patent ID: 7047748

Claim:
A process for reducing a concentration of nitrogen oxides, NO x , in an effluent gas stream from a combustion of liquid or gaseous carbonaceous fuel in a gas turbine combustion chamber, comprising the steps of: identifying a gas combustion temperature zone within said combustion chamber that is downstream of a zone of initial gasification of said liquid fuel and initial combustion of said liquid or gaseous carbonaceous fuel and where in an absence of any steps to cool a downstream gas temperature zone, approximately above 2500° F., thermal NO x production is provided; injecting water droplets of varying size between 10 μm to 1000 μm by means of one or more nozzles that form a flat, planar, fan shaped, spray pattern which is oriented perpendicular to said effluent gas stream and is of cross-sectional area to intercept all of the effluent gas stream in said gas combustion temperature zone, and whose mean and maximum size of said droplets depend on the dimensions of said gas combustion temperature zone in said chamber; varying hydraulic or air atomizing pressure in at least one injector in order to permit distribution and vaporization of different sized droplets at different locations within said gas combustion temperature zone, taking place during said injecting step; and adjusting a position of an injector droplet outlet of said at least one injector within said combustion chamber based on an outer edge of said gas combustion temperature zone identified in said identifying step, said adjusting step positioning said injector droplet outlet adjacent to said outer edge of said gas combustion temperature zone identified in said identifying step, with evaporation of said flat, planar, fan-shaped, spray pattern cooling said gas combustion temperature zone within said combustion chamber to temperatures, approximately below 2500° F., where thermal NO x production is suppressed.