利用计算流体动力学(Computational Fluid Dynamics,CFD)对驻极体过滤器内的气-固两相流动特性进行数值研究,计算了过滤器内部电场的分布及带电颗粒经过驻极体过滤器时的压力损失和渗透率。结果表明:对于颗粒粒径dp≤0.1μm的颗粒,静电力在其捕集过程中占主导作用;随着粒径的增加,静电力的影响逐渐减弱。对于粒径范围在0.05~0.5μm的颗粒,驻极体过滤器的渗透率随迎面风速的增大而增大。另外,从驻极体过滤器内颗粒运动轨迹可以看出,在驻极体过滤器的背风面有带电颗粒的沉积,这种颗粒沉积可能是驻极体过滤器低渗透率,低阻力的主要原因之一。
The gas-solid two phases flow characters in an electret filter was simulated by computational fluid dynamics(CFD) method,and the internal electric field distribution,pressure drop and the permeability of the electric particles which pass through the electret filter were calculated.The results indicate that the electrostatic force is dominant when the particle size is smaller than 0.1μm;the effect of the electrostatic force on the permeability of the electret filter wear off with the increasing particle size;the permeability of the electret filter is increased with the face velocity when the particle size range is 0.05-0.5μm.In addition,it can be seen from the movement of particle trajectory in the electret filter,some particles are deposited on the back of the electret fiber,which may be one of the main reasons of low permeability and low pressure drop in the electret filter.