Bipolar Precharger for Hybrid Electrostatic Filtration Systems

Both hybrid electrostatic filtration and agglomeration technologies can effectively improve the efficiency of fine particle collection. A hybrid electrostatic filtration system with a wire-tube bipolar precharger was developed on the basis of bipolar transverse plate electrostatic precipitation technology. Theoretical analyses of electric field and flow field distribution showed that a uniform electric field and high turbulence intensity improve ion migration and particle agglomeration in the novel wire-tube bipolar precharger. The influence of unipolar and bipolar prechargers on dust removal was investigated. In the hybrid electrostatic filtration system with the bipolar precharger, the corona current was 30% higher, the particles deposited on the surface of the filter bag were 19% larger, and the pressure drop was 30% smaller than a filtration system with a unipolar precharger. When silicon powder with a median diameter of 1.7 mu m was used, the mean penetration of the experimental device with the bipolar precharger was 45% lower than that of the experimental device with the unipolar precharger.