| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the corrosion of an air preheater, etc., by providing a reaction zone where CaCO3 powder is added and reacted with the SO3 , etc., in the waste gas and a dust collector for collecting the unreacted CaCO3 on the downstream side of the reaction zone in a waste combustion gas passage between the outlet of the economizer of a combustion furnace and the air preheater. SOLUTION: The waste combustion gas formed by burning a sulfur-contg. fuel is passed through a denitrator 16, an air preheater 6, an electric precipitator 8 and a wet desulfurizer 9 and treated. In this case, a reaction zone 19 where CaCO3 powder is added and reacted with the SO3 , etc., in the waste gas and a dust collector 11 on the downstream side are arranged in a flue 5 extended from the economizer 4 to air preheater 6. The CaCO3 powder is introduced into the reaction zone 19 from a spray nozzle using compressed air. The introduced desulfurizing agent reacts with the SO3 , etc., in the combustion gas, and the SO3 , etc., are removed. The powder of the desulfurizing agent is recovered by the dust collector 11, introduced into a recovery hopper 12 and partly recycled as the desulfurizing agent of the wet desulfurizer 9.</p> |
