Effect of charged spray evaporation of desulfurization wastewater on fine particle removal efficiency of electrostatic precipitator

Abstract

The removal of fine particles from coal-fired power plants and the zero-discharge treatment of desulfurization wastewater (DW) from wet desulfurization are critical issues. In this study, we propose a charged droplet evaporation technology of DW for efficient electrostatic dust removal, aiming to achieve zero discharge of DW and effectively remove fine particles. We experimentally studied the effect of charged DW droplet evaporation on the dust removal efficiency of an electrostatic precipitator (ESP) and analyzed the internal mechanism. The results revealed that the removal efficiency of fine particles by ESP was affected by electrode voltage, atomization pressure, DW volume flow, and Cl− concentration. The main internal mechanisms that improved the removal efficiency of fine particles were agglomeration and pre-charging of the particles. Increasing the electrode voltage proved to be the most effective method in enhancing the removal efficiency of fine particles. Specifically, when the electrode voltage was increased from 0 to 12 kV, the removal efficiency of PM2.5 by ESP demonstrated an increase of greater 14 %. The removal efficiency in the penetrating window exhibited an increase of greater than 8 %. Furthermore, augmenting the atomization pressure and DW volume flow also contributed to the improvement in fine particle removal by ESP. In contrast, increasing the Cl− concentration had a detrimental effect on the removal process.