SWIRL-TYPE PULVERIZED-FUEL BURNER WITH LOW EMISSION OF NITROGEN OXIDES Russian patent published in 1996 - IPC

FIELD: solid fuel combustion. SUBSTANCE: burner has one or more external secondary-air cylindrical coaxial channels with swirlers and one or two air-fuel mixture coaxial cylindrical channels with swirlers. Installed in internal near-axis fuel-air mixture channel downstream of swirler along flow movement are contracting cylindrical insert and contraction-diffusion checker downstream of the latter; distance between exit edge of swirler and closest end of contracting cylindrical insert is (0.3-0.5)d and distance between outlet section of contracting cylindrical insert and closest end of contraction-diffusion checker is maximum 0.5d; angle of contraction portion of contraction-diffusion checker is 20-40 deg., where d is inner diameter of external pipe in annular cylindrical channel for fuel-air mixture at inlet of contracting cylindrical insert. EFFECT: improved design. 1 dwg