双塔双循环工艺在脱硫系统改造中的应用

Application of Double Tower and Double Circulation Process in Desulfurization System Transformation

山西某厂现有4台焦化炉及配套的脱硫系统,脱硫系统中1^(#)与2^(#)脱硫塔互为备用,3^(#)与4^(#)脱硫塔互为备用。因为生产条件变化,烟气量及烟气中的SO_(2)浓度增加,已有的脱硫系统不能满足生产变化后的烟气脱硫需求,为了达到环保超低排放的要求,需要对脱硫系统进行升级改造。本方案不对原脱硫系统进行改造,而在现有的脱硫塔进口串联1个1级脱硫塔,采用双塔双循环工艺进行脱硫,在连接烟道设置的烟道脱水装置大部分拦截来自1级脱硫塔的被烟气夹带的浆液,再通过底部排放口排入1级脱硫塔持液段。经实践证明,双塔双循环工艺在脱硫系统改造中的运用取得了理想的效果,可供燃中、高硫煤机组超低排放改造借鉴。

A plant in Shanxi has four coking furnaces and supporting desulfurization system.In the desulfurization system,1^(#)and 2^(#)desulfurization towers are standby for each other,and 3^(#)and 4^(#)desulfurization towers are standby for each other.Due to the change of production conditions,the amount of flue gas and the concentration of SO_(2)in flue gas increases.The existing desulfurization system can not meet the requirements of flue gas desulfurization after production changes.In order to meet the requirements of environmental protection and ultra-low emission,the desulfurization system needs to be upgraded.In this scheme,the original desulfurization system is not reformed.A primary desulfurization tower is connected in series at the inlet of the existing desulfurization tower,and the dual tower dual cycle process is adopted for desulfurization.Most of the flue dehydration devices set in the connecting flue intercepts the slurry entrained by the flue gas of the primary desulfurization tower,and discharges it into the liquid holding section of the primary desulfurization tower through the bottom discharge port.Practice has proved that the application of double tower and double circulation process in the transformation of desulfurization system has achieved ideal results,it can provide reference for ultra-low emission transformation of medium and high sulfur coal generating units.