Patent ID: 6790031
Filing Date: 2004-09-14
Classification: F23C,Y02E

Abstract:
A tangential fired boiler comprising:a circumferential wall defining a combustion zone; a plurality of fuel inlets disposed along said circumferential wall, said plurality of fuel inlets injecting fuel at non-uniform rates in order to produce localized fuel rich, oxygen poor zones and fuel lean, oxygen rich zones within the combustion zone, and to cause ambient boiler gases to be entrained into and mix with the oxygen poor zones to achieve fuel staging of the boiler; wherein said plurality of fuel inlets are arranged substantially vertically along said circumferential wall; and wherein said plurality of fuel inlets are arranged such that an uppermost fuel inlet injects fuel at a lowest rate, a lowermost fuel inlet injects fuel at a highest rate, and fuel inlets located between the uppermost and lowermost fuel inlets inject fuel at intermediate rates along a gradient such that a localized fuel rich, oxygen poor zone is created toward a bottom of the combustion zone and a fuel lean, oxygen rich zone is created toward a top of the combustion zone.