水力喷射-空气旋流器用于湿法烟气脱硫及其传质机理  

Wet desulfurization of flue gas and mass transfer mechanism in water-sparged aerocyclone

作　　者：赵清华[1] 全学军[1] 程治良[1] 晏云鹏[1] 

机构地区：[1]重庆理工大学化学化工学院,重庆400050

出　　处：《化工学报》2013年第11期3993-4000,共8页CIESC Journal

基　　金：国家自然科学基金项目(21176273);重庆市科技攻关项目(CSTC2010AA7060);重庆市教委项目(KJ120816)~~

摘　　要：在一种新型高效的气液传质设备——水力喷射-空气旋流器（WSA）中,以Ca（OH）2料浆为吸收剂进行了模拟烟气湿法脱硫的实验研究。结果表明：脱硫率随进口气速增加而增加;随液体喷射速度增加先增加,增加到一定程度后几乎不变;随烟气中SO2的进口浓度增加而减小,存在一适宜的Ca（OH）2浓度和回流比。在气体流量24～72 m3·h-1、循环液体量0.4～0.8 m3·h-1、料浆中Ca（OH）2浓度7500 g·m-3时,对SO2浓度为1891～6373 mg·m-3的烟气进行湿法脱硫,脱硫率达88.9%～97.7%,且WSA的旋流气体和喷射液体在湿法脱硫中具有自清洁能力,未发现内部结垢和喷孔堵塞现象。总体积传质系数KGa、有效相界面积a均随进口气速uG增大而增大,而总传质系数KG随uG增加变化较小;当液体喷射速度 uL≤0.26 m·s-1时,KGa和KG随uL增加快速增大,之后增加缓慢,而a随uL几乎线性增加,KGa和KG随吸收剂中Ca（OH）2浓度cL增加有一最大值。结合实验数据拟合得到了相关的经验公式,这些关联式能较好地预测WSA的湿法脱硫传质性能。气体旋流场强度对总体积传质系数KGa和有效相界面积a起支配作用,脱硫传质过程同时受气膜和液膜阻力控制,但以液膜控制为主。Wet desulfurization of flue gas was investigated with Ca（OH）2 slurry as absorbent in a water-sparged aerocyclone（WSA）,new and high efficiency gas-liquid mass transfer equipment.The results show that the removal efficiency of SO2 increases with the inlet gas velocity,first increases linearly with liquid jet velocity uL,and then remains almost constant when uL is equal to or greater than 0.29 m·s-1.The removal efficiency of SO2 decreases as SO2 concentration in the flue gas increases,and presents a maximum value with the increase of liquid reflux ratio and Ca（OH）2 concentration in the absorbent slurry.The removal efficiency of SO2 can reach 88.9%-97.7% under the following conditions：flue gas flow rate of 24-72 m3·h-1,absorbent recirculation flow rate of 0.4-0.8 m3·h-1,Ca（OH）2 concentration in absorbent of 7500 g·m-3,and SO2 concentration in flue gas of 1891-6373 mg·m-3.No fouling and blocking were found in the WSA because of the self-cleaning ability of the cyclone gas and liquid jet.The mass transfer mechanism in the WSA was also investigated.The results show that the overall volumetric mass transfer coefficient KGa and the interfacial area a increase with the increase of inlet gas velocity uG,the overall mass transfer coefficient KG increases with uG slowly.KGa and KG increase quickly with liquid jet velocity uL when uL≤0.26 m·s-1 and then increase slowly,and a increases almost linearly with the increase of uL.As Ca（OH）2 concentration cL increases,KGa and KG increase first and then decrease.The empirical formulae fit the experimental data well and could be used to predict the mass transfer characteristics for wet desulfurization in WSA.Under the experimental conditions,the mass transfer in wet desulfurization in the WSA is controlled by both gas film and liquid film,mainly by liquid film.

关 键 词：水力喷射-空气旋流器 湿法脱硫 气-液传质 有效相界面积 

分 类 号：TQ021.1[化学工程]