荷电液滴联合声波捕集颗粒物的过程和特性

Process and characteristics of capture of particles by charged droplet and acoustic waves

搭建显微可视化平台,观测以半山电厂灰为代表的颗粒物在电场及声场作用下相对于悬垂荷电单液滴的运动和捕集特性,利用激光粒度仪对颗粒物的凝并效果进行验证.实验结果显示:对液滴进行荷电,可以将以惯性捕集为主要作用的灰颗粒绕流运动变为以静电力(介电泳力、库仑力)为主导的吸引作用,颗粒物在液滴表面的沉积状态由树枝状变为紧密堆积状态,而增加声场后,在颗粒初始轨迹之上叠加了往复的振动.荷电液滴引入的静电力和液桥力强化了团聚体内部的黏附作用.进一步的粒径分布表征实验发现,荷电液滴和声波的加入均可以有效促进颗粒的团聚长大.

A microscopic visualization system was constructed to observe the movement and capture of particles around a charged single droplet under electric and acoustic field.Ash from Banshan Power Plant was used as representative particles.A laser particle size analyzer was used to verify the effect of agglomeration.The experimental results show that the inertial capture can be changed to attraction dominated by electrostatic forces (dielectrophoretic force,Coulomb force) by charging the droplet,and particle deposition on the surface of droplet changes from dendritic to tightly stacked.The trajectories of particles show reciprocating vibrations when adding acoustic field.The electrostatic force and liquid bridge force introduced by the charged droplets can enhance the internal adhesion of agglomerates.Further particle size distribution experiments show that both charged droplets and sound waves can effectively promote the agglomeration of particles.