PURPOSE: To accelerate desulfurizing reaction and improve desulfurization rate by generating supersonic waves or sound waves in an oven for jetting powdery desulfurizing agent, by the energy of which sulfur oxide and powdery desulfurizing agent in combustion gas are agitated.

CONSTITUTION: A main pulverized coal burner 2 is mounted on the lower part of the side of a vertical calcination oven 1, above which a secondary pulverized coal burner 3, an oven fire.air port 4 and a desulfurizing agent feeding nozzle 5 are successively mounted. A supersonic wave or a sound wave generator 6 is installed almost halfway of the oven wall, with which a supersonic wave or a sound wave generating amplifier 7 is connected. Sulfur oxide and powdery desulfurizing agent in combustion gas can effectively be agitated and mixed by the energy generated by burning pulverized coal in said calcination oven 1, jet feeding the desulfurizing agent and generating supersonic waves or sound waves, and as a result, desulfurizing reaction is accelerated to increase desulfurizing rate to a large extent.