METHOD FOR IGNITING A PULVERIZED-COAL ANNULAR BURNER FLAME

摘要

ABSTRACT OF THE DISCLOSUREA method is provided herein for supplying solid, pulverized fuelto a pulverized-fuel pilot light of an annular flame, coal dust burner. Themethod includes, firstly, supplying the coal dust burner with a fuel streamcomprising a mixture of pulverized fuel and carrier air from a pulverizingplant via a main fuel supply conduit, that stream having a cross-section withareas of pulverized fuel having different grain sizes. The second step involvesselectively withdrawing a portion of the pulverized fuel and carrier air ata withdrawal site in the main fuel supply conduit which faces in the upstreamdirection with respect to the direction of flow of the stream so as to with-draw pulverized fuel of a grain size different from that comprising the cross-section of the entire stream. The third step involves separating the with-drawn pulverized fuel from the carrier air and returning the carrier air tothe main conduit at a location downstream from the site of the withdrawal.The fourth step involves feeding the withdrawn pulverized fuel to a storagebunker for a subsequent burning by the pilot light. The fifth step involvesfeeding the withdrawn pulverized fuel from the storage bunker to the pilotlight when the coal dust burner is extinguished wherein a flame is availablefor reigniting the coal dust burner when ignition is necessary. The finalstep involves withdrawing additional portions of pulverized fuel as describedabove to keep a sufficient supply of pulverized fuel of selected grain sizein the storage bunker for use by the pilot light when the coal dust burner isextinguished.