To stop swirling of pulverized coal flow and form an igniting swirling flow by turbulent flow without deteriorating thick and thin fuel concentration separation effect by arranging flame stabilizing blocks above an inner cylinder of a pulverized coal nozzle and a flame stabilizer protruding from a distal end periphery of an outer cylinder and broadening toward a downstream side.
Flame stabilizing blocks 8 constitute a plurality of straight passage extending in an axial direction and an annular passage, which does not break a pulverized coal passage, between an outer cylinder 15 of a pulverized coal nozzle 6 and the flame stabilizing blocks and are arranged above an oil primary air nozzle 12 which corresponds to an inner cylinder. Pulverized coal fed as shown in an arrow (A) is made to swirl in an upstream side of the pulverized coal nozzle 6 to effect thick and thin fuel concentration separation by centrifugal force, and when reaching a top end portion, the pulverized coal flow is turned into a straight flow with maintaining thick and thin fuel concentration separated state by the flame stabilizing blocks 8 to form a thick pulverized coal portion 9 and a thin pulverized coal portion 10, both of which are charged into an after flow. The thick pulverized coal portion 9 achieves flame stabilization in a whole periphery because being oriented to a flame stabilizer 3 side, and on the other hand, the thin pulverized coal portion 10 forms an igniting swirl by the flame stabilizing blocks 8 so that igniting performance toward a center side of the pulverized coal nozzle 6 is enhanced.
ISODA TAKAHIRO
KOBAYASHI YOSHINORI
ICHINOSE TOSHIMITSU
