PURPOSE: To prevent occurrence burnout of a flame stabilizing means and of slagging in the flame stabilizing means by providing a projecting body in extension into a furnace beyond the flame stabilizing means and by interrupting thereby a radiant heat from inside of the furnace moderately so that an excessive rise of temperature is suppressed.
CONSTITUTION: The end part of the inner peripheral wall 62 of a projecting body 6 is expanded in the radial direction. Therefore the flow velocity of secondary air is lowered thereat and the air is consumed for flame stabilization without disturbing a jet stream of a mixed fluid. Accordingly, a high-temperature reducing flame being stable is formed and held and production of NOx is suppressed. A flame stabilizing ring 3 is surrounded by a reducing atmosphere and a high-density area of pulverized coal is formed in the vicinity of the flame stabilizing ring 3 by a vortex flow. Furthermore, it is exposed to a high temperature due to a radiant heat from a furnace 2. Since the projecting body 6 extends into the furnace 2 beyond the flame stabilizing ring 3, however, the radiant heat to the flame stabilizing ring 3 is interrupted thereby moderately and the flame stabilizing ring 3 is prevented from being heated to an excessively high temperature. Even when the unit capacity of burning equipment is large, accordingly, burnout of the flame stabilizing ring 3 or occurrence of slag can be prevented.
KURAMASU KIMIHARU
NAKASHITA SHIGETO
ISHII KEIJI
JINBO TADASHI
HODOZUKA KUNIO
BABA AKIRA
KOBAYASHI YOSHINOBU
