错流旋转填料床脱除细颗粒物研究

摘要

Fine particles are dangerous to environment and mankind,and could not be removed by common dust separator. The rotating packed bed combines various dust removal mechanisms,and has high collection efficiency and low power consumption. A pilot-scale system was set up by using fly ash with average particle size of 2.25μm as fine particles and cross-flow rotating packed bed as wet scrubber in this paper. A method of measuring particle size distribution of dust and calculating the classification efficiency using Mastersizer was proposed. The system was investigated at different rotating speeds,liquid-gas ratios,and gas flowrates. Classification efficiency increased with increasing rotating speed and liquid-gas ratio,and removal efficiency could be up to 96%. These data provided strong support to industrialization of high gravity wet cleaning. Results of fitted regression of classification efficiency showed that correlation coefficient R was 0.9808. Classification efficiency of cross-flow rotating packed bed was higher than common wet dust collector and impact of particle size was less. Cross-flow rotating packed bed can be used to remove fine particles in gas and has broad application prospect.%细颗粒物对环境和人体都会产生较大危害，传统除尘设备无法高效脱除。超重力旋转填料床复合了多种除尘机制，除尘效率高，能耗低。本文采用平均粒径为2.25μm的粉煤灰模拟细颗粒物，错流旋转填料床为湿式除尘设备，搭建了中试规模的实验系统。提出了使用激光粒度分析仪测量粉尘粒度分布并计算分级效率的方法，通过实验考察了转速、液气比和气量对错流旋转填料床分级效率的影响。研究表明，分级效率随转速、液气比、气量的增大而增大，PM2.5的脱除效率可达到96%，为超重力湿法除尘的工业化推广提供有力的数据支撑。对分级效率曲线进行拟合，相关系数 R=0.9808。对比发现，错流旋转填料床的分级效率高于一般湿式除尘器，对微米级粉尘也有很高的脱除率，可以高效脱除气体中的细颗粒物，应用前景广阔。