Dust removal performance of two-stage electrostatic precipitators and its influencing factors

Abstract

In this work, the dust removal performance of a two-stage electrostatic precipitator and its influencing factors are studied. A numerical model is developed to describe the physical processes in the two-stage ESP, including airflow, corona discharge, particle charging, and particle dynamics. The accuracy of the model is experimentally validated on a wire-plate two-stage ESP. The effects of geometric sizes, voltage parameters, and working conditions on the dust removal performance are simulated and analyzed. Additionally, a supplementary metric named as complete dust removal length is proposed to measure the dust removal performance. Based on an ideal condition that simplifies particle motion in the collection stage, a general quantitative relationship between the dust removal performance of a two-stage ESP and its influencing factors is formulated. It is shown that the complete dust removal length is proportional to the square of the collection plate spacing and inversely proportional to the repelling voltage. For particles with large size, the space charging dominates, and the complete dust removal length is proportional to the particle diameter and inversely proportional to the inlet wind speed. For particles with small sizes, the diffusion charging dominates, and the complete dust removal length increases significantly with the decrease of particle size. In this case, the inlet wind speed contributes more to the dust removal performance.