| 摘要 |
<p>PURPOSE:To always keep a desulfurization ratio high as well as to eliminate an oxidizing tower, by forming a recirculation tank subjecting an absorbing liquid to aeration treatment to promote the dissolution of an absorbent and a gypsum tank subjected to aeration treatment while a gypsum forming agent is supplied in a liquid accumulation tank. CONSTITUTION:The inside of the liquid accumulation tank 4 of an absorbing tower 11 is divided into a gypsum tank 20 and a recirculation tank 21 by a partition wall 19. To an absorbing liquid sprayed from sprayers 18 and flowed down while absorbs SOx in an exhaust gas, sulfuric acid 23 is supplied as a gypsum forming agent in the gypsum tank 20 and unreacted CaCO3 is thoroughly converted to gypsum while CaSO3 is oxidized by subjecting the same to aeration treatment by air from a sparger 22a. Because the formed gypsum 24 is sent to a filter machine to be recovered and a filtrate 25 is returned to a tank 14 to be reused by recirculation, the Cl concn. in the absorbing liquid 15 within the recirculation tank 21 is gradually raised and the dissolution speed of CaCO3 is lowered but, by aeration treatment due to air from a sparger 27a, the solubility and the dissolving speed of CaCO3 are enhanced.</p> |
