The influence of electrohydrodynamic secondary flow on the collection efficiency and deposition pattern in ESP

Abstract

Electrostatic precipitator (ESP) is widely used for dust removal from flue gas in industry. In the electrostatic precipitation, the electrohydrodynamic secondary flow (EHD) produced by corona ionization has an important influence on the characteristics of particle transport and the collection efficiency of ESP. In this work, a comprehensive ESP model with interaction of multiple physical fields is established to study the EHD effect in ESP. The numerical results show that the EHD generally can increase the streamwise velocity of airflow near the collection plate, which makes the removal performance of ESP worsen. Meanwhile, the EHD has a significant effect on the particle deposition pattern, especially at lower flue gas velocity. When the needle tip of discharge electrode points to the collection plate, the EHD can promote the circulation of airflow near the corona wire, increase the probability of particle charging, and then improve the collection efficiency of ESP.