粉尘双极荷电对滤料电荷累积抑制作用

为解决单极性电袋复合除尘器因滤料电荷积累导致清灰难和反电晕烧袋问题，将线管式双极荷电器引用到电袋复合除尘技术中。基于电晕电流最大化方法进行荷电器的电极结构优化实验。当电晕极采用RS芒刺线、管电极采用不锈钢管时，荷电器的较优极配为管电极直径25 mm、管间距120 mm、电晕线到管电极的异极距80 mm。在荷电器和导电纤维滤料组装成的静电增强纤维过滤装置上，分别进行粉尘单极荷电和非对称双极荷电情况下滤料电荷积累量的对比实验。实验粉尘采用中位径3.5 μm硅微粉。在过滤风速为0.17 m·s-1、平均电场强度2.5～3.0 kV·cm-1的实验条件下，当气流含尘浓度为700 mg·m-3时，双极荷电粉尘在滤料上累积电荷产生的电流值比单极荷电粉尘滤料上累积电荷产生的电流值低约25%，表明双极荷电对滤袋电荷积累有明显的抑制作用。

Charge accumulation restraining effect of bipolar charged particles on fabrics

In order to solve the problem of the dust cleaning difficulty and the bag burning risk due to the charge accumulation on the fabrics in the unipolar electrostatic enhancement bag filter, a wire-tube bipolar discharger was applied. Firstly, the electrodes of the wire-tube bipolar discharger were optimized experimentally based on the corona current maximization. When the RS barbed wire and the stainless steel tube were used as the discharger electrodes, the appropriate configuration was that, the tube electrode diameter was 25 mm, the span of the tubes was 120 mm, and the distance between the wire electrodes and tube electrodes was 80 mm. Then, the comparison experiments about the charge accumulation on the conductive fabrics were carried out when the unipolar charged particles and the dissymmetric bipolar charged particles were generated by the unipolar discharger and the bipolar discharger respectively. The silicon powder with 3.5 μm medium diameter was used as the test particles. The filtration velocity was 0.17 m·s-1. The average electric field strength was in the range of from 2.5 to 3.0 kV·cm-1. The results showed that the current produced by the charge accumulation of the bipolar charged particles on the fabrics was about 25% lower than that of the unipolar charged particles on the fabrics when the inlet silicon particle concentration was 700 mg·m-3, which indicated that the restraining effect on the charge accumulation on the fabrics was obvious when the bipolar discharging method was used.