石灰石-石膏湿法脱硫过程中浆液液滴及细颗粒物迁移转化特性研究

Study on Transformation Characteristics of Slurry Droplets and Fine Particles During Limestone Gypsum Desulfurization Process

脱硫浆液蒸发夹带作用是导致石灰石-石膏湿法脱硫过程中细颗粒物物性变化的重要因素。利用相位多普勒粒度分析(PDA)测试系统、电称低压冲击器(ELPI^+)、激光粒度分析仪测试分析了脱硫浆液晶体特性、脱硫净烟气中液滴及细颗粒物排放特性间的关系。结果表明:脱硫浆液中晶体以板状、棱柱状为主,其特性与净烟气细颗粒物形貌存在一定联系;通过优化脱硫浆液结晶过程促进晶体粒径增大、适当调节脱硫浆液及塔入口烟气温度等措施,可在一定程度上减弱脱硫浆液的夹带作用,减少塔出口液滴及细颗粒物的排放。

The evaporation and entrainment of desulfurization slurry are important factors leading to the change of physical properties of fine particles during limestone gypsum wet flue gas desulfurization process.To analyze the relationship between the crystal characteristics of desulfurization slurry and the emission characteristics of desulfurization droplets and fine particles in cleaned flue gas,a series of experiments were carried out using the phase Doppler particle analysis(PDA)system,electronic low-pressure impactor(ELPI+)and the laser particle size analyzer.Results show that the crystal characteristics of desulfurization slurry are related to the morphology of emitted fine particulates,which are mainly plate-like and prism-like.By optimizing the crystallization process of desulfurization slurry to increase crystal sizes and by adjusting the temperatures of desulfurization slurry and flue gas at the tower inlet,the entrainment of desulfurization slurry could be weakened to some extent,thus the emission concentration of droplets and fine particles could be reduced.