PULVERIZED-COAL BURNER WITH LOW YIELD OF NITRIC OXIDES Russian patent published in 1995 - IPC

FIELD: power engineering. SUBSTANCE: burner has a housing with coaxially installed central pipe and shell, forming peripheral and internal annular ducts for supply of secondary air and fuel-air mixture respectively, as well as a fuel-air mixture flow dissector. The dissector is installed at the outlet from internal duct and made as a central nozzle with inlet and outlet ends and diffusion annular orifice enclosing the above nozzle; the diameter of the nozzle outlet equals 0.1 to 0.5 of the diameter of the internal duct for supply of fuel-air mixture. The outlet end of the central nozzle projects beyond the limits of the housing exit section over a distance equal to 0.1 to 0.5 of the diameter of the peripheral duct. The central nozzle is made of two sections- converging tube and cylinder-arranged in succession in the direction of flow motion; the converging tube has a curvilinear surface with a smoothly varying radius of curvature. The central nozzle is installed for longitudinal motion, and it is provided with a device for its motion. The central nozzle is made as an ejector, and the central pipe is installed for longitudinal motion. An additional pipe is coaxially installed in the peripheral duct forming an impassable duct between the peripheral and internal ducts, having a width equal to at least 0.1 diameter of the peripheral duct. EFFECT: decreased yield of nitric oxide. 6 cl, 1 dwg