旋流雾化水膜除尘器内尘粒运动特性及分离效率

Moving characteristics and separating efficiency of particles in rotary atomized water film dust collector

基于气固多相流复杂的运动特征 ,结合旋流雾化水膜除尘器的特点 ,同时考虑尘粒碰壁面黏附与反弹条件 ,颗粒间的碰撞与并聚、喷水加湿对颗粒间并聚及碰撞、颗粒运动特性的影响 ,并考虑颗粒对气相的作用 ,构建了描述旋流雾化水膜除尘器内湍流气固多相流的三维时均方程组 ,模型封闭采用 k-ε/RNG模型 ,数值模拟了旋流雾化水膜除尘器内尘粒运动特性及分离效率。结果表明 :在设置水膜除尘器尘粒遇壁面条件时 ,应设置尘粒碰壁为黏附 ;除尘器内干段、湿段比例、尘粒粒径、尘粒入口位置等对除尘效率高低均存在影响 ;壁面水雾膜的黏附及喷水对尘粒并聚影响较大 ,尘粒在除尘器内运动位移小于尘粒碰壁面反弹及不考虑尘粒并聚的情况 ,越有利于尘粒分离 ;除尘器入口速度越大及喉部喷水速度越大 ,越有利于尘粒的除去。

Based on the study of the complex moving characteristics of gas-solid multiphase flow and the special feature of the rotary atomized water film dust collector, the 3-D time average equations were developed, taking account of the stick and rebound conditions on the wall, the collision and the aggregation among the particles and the infection for adding moisture through ejecting water to the collision and the aggregation among the particles. The k-ε/RNG was adopted to close the equations. Numerical simulation of the moving characteristics and separating efficiency of particles in rotary atomized water film dust collector were performed. The results show that the stick condition on wall should be used. The scale between dry and wet segment, the diameter of particle, and the initial position of particle in dust collector play an important role in deposit efficiency. And the parameters of the stick condition and ejecting water have an vital effect for the collision and the aggregation among the particles, and the deposit efficiency of dust collector.