电除尘凝聚预处理技术对提钒转炉烟气除尘超低排放的影响

Effect of dust agglomeration pretreatment of ESP on the ultra-low emission of primary flue gas from vanadium extraction converters

针对提钒转炉烟气粉尘中10μm及以下粒级的含量高于脱碳转炉,较难达到超低排放要求的问题,本文提出对提钒转炉一次烟气进行溶液喷雾凝聚预处理,再利用干式电除尘器进行静电吸附的工艺方法,并对3种凝聚剂进行了凝聚效果试验。结果表明,KGM-g-PDMC凝聚效果最好,可以使100%除尘粒径降到120μm,对10μm粒级以上大小颗粒物除尘效率达到了70%,而且通过适当增大凝聚剂浓度、降低烟气温度,可以增加KGM-g-PDMC的凝聚效果。通过对有、无凝聚剂处理的粉尘进行扫描电镜检测,发现凝聚预处理不同于静电吸附作用,凝聚作用不单使得颗粒物粒径变大,而且可以发生链式附聚耦合效应,使得比表面积进一步增大,更加有利于后续颗粒的继续附聚耦合。该附聚耦合工艺采用的凝聚剂KGM-g-PDMC经济合理,处理后的提钒转炉烟气可以满足超低排放要求,而且投资小于开发新型电除尘器,具有推广价值。

The distribution ratio of PM_(10) dust in the vanadium extraction process is higher than that of traditional decarburization converters,it’s hard to meet ultra-low emission standard.In this paper,the process of pre-treatment by dust agglomeration followed by electrostatic adsorption with dry ESPs was proposed to treat the primary flue gas from vanadium extraction converters,and tests were carried out on the performance of three coagulants.The test results indicate that the coagulant KGM-g-PDMC shows the best effect by reducing dc100 to 120 μm and enabling the removal rate of 10 μm and above particulate matter to reach 70%;moreover,the coagulation effect of KGM-g-PDMC is improved with the increase of its concentration and the decrease of off-gas temperature.According to the SEM detection of the dust with and without coagulation pre-treatment,it was found that agglomeration could contribute to convergence-adsorption coupling effect while enlarging particle size,making the specific surface area of dust further increased,which favors to continuous convergence-adsorption coupling in the downstream treatment.In this process,the coagulant KGM-g-PDMC is cost-effective,the off-gas after treatment can meet the requirement of ultra-low emission and the overall investment is lower than that of developing a new type of ESP,thus,the process is worthy of promotion.