湿法烟气脱硫吸收塔循环氧化槽的改进

An Improvement on the Circulation Oxidation Tank of an Absorption Tower for Wet Flue-gas Desulfurization

针对湿法烟气脱硫系统三塔合一后 ,脱硫率和石膏品质均有所下降的问题 ,提出吸收塔底部循环氧化槽分为氧化槽和加料槽的改进方案 ,并在并流降膜式湿法脱硫装置上进行了改进前后的试验。试验结果显示 ,改进后的脱硫装置缓解了脱硫率和石膏品质之间的矛盾 ,加料槽高pH值使得塔内维持高的脱硫率 ;而氧化槽内低pH值有利于石灰石的溶解和SIV的氧化 。

After the three towers of a wet flue-gas desulfurization system was grouped into one, there emerged the problem of a decrease in desulfurization efficiency and gypsum quality. To cope with this problem, an improved scheme was put forward, which consists in dividing the circulation oxidation tank at the bottom of the absorption tower into an oxidation tank and a material-feed tank. Moreover, tests were conducted on a parallel-flow falling-film wet desulfurization plant before and after the implementation of the improved scheme. The results of the tests indicate that the improved desulfurization plant has alleviated the contradiction between the desulfurizaton efficiency and the gypsum quality. The high pH value of the material-feed tank makes it possible to maintain a high desulfurization efficiency in the tower, while the low pH value of the oxidation tank is favorable to the dissolution of limestone and the oxidation of SIV, thereby enhancing the quality of gypsum.