Integrated reburn system for NO.sub.x control from cyclone-fired boilers

摘要

An integrated reburn system for a cyclone-fired boiler has a reburn fuel feed nozzle through a cyclone burner into the cyclone barrel, or furnace, at a region of low-velocity fuel and air movement. The reburn fuel is injected at high velocity and mostly does not mix with the combustion fuels and gases within the cyclone barrel. The reburn fuel passes through the re-entrant throat of the cyclone into the main furnace, where it forms a reburn zone having a reducing atmosphere in which the reburn fuel reacts with combustion gases from the main combustion zone to convert NO.sub.x to N.sub.2, thereby reducing the amount of NO.sub.x emissions produced by the furnace.