空气过滤材料静电衰减机理的实验研究

Experimental Study on Mechanism of Static Electricity Attenuation for Fibrous Filter Medium

采用不同形态、不同荷电特性的气溶胶对静电纤维过滤材料进行积尘实验,观测滤料积尘过程中的表面电势、过滤效率和纤维形态的变化.结果表明不同荷电特性KCl(氯化钾)气溶胶积尘的滤料表面电势随积尘量增加的变化趋势不同,但滤料的效率不随积尘增加而变化;液态DEHS(癸二酸二辛酯)气溶胶容尘实验发现,滤料表面电势和效率都急剧衰减.实验结果以及不同形态气溶胶积尘滤料的扫描电镜表明造成滤料静电衰减的机理主要是屏蔽作用.

A series of experiments with different charge aerosols were carried out to investigate the mechanism of static electricity attenuation for fibrous filter medium.DEHS and three different charge characters of KC1 were used to challenge electrostatic fibrous filter medium.The surface potential and filtration efficiency were tested and morphology of medium was observed through scanning electron microscope （SEM） for different dust loading periods.The results of experiments show that surface potential of filter mediums challenged with charge KC1 （Potassium chloride） has different variation trends with dust collection,however,the efficiency does not change obviously.Surface potential and efficiency of filter mediums challenged with diethyl hexyl sebacate （DEHS）decrease sharply.Both experimental results and SEM of medium challenged with different morphology show that the mechanism of electrostatic attenuation for filter medium is mainly due to electrostatic shielding effect.