Numerical study on electrohydrodynamic flow and fine-particle collection efficiency in a spike electrode-plate electrostatic precipitator

Abstract

In this work, a numerical study on the electrohydrodynamic secondary flow and transport of fine particles has been carried out based on spike electrode-plate electrostatic precipitator (ESP). The effect of the inlet flow velocity, negatively applied voltage, and position of spike tip on airflow streamlines distribution are analysed in detail. The electrohydrodynamic (EHD) secondary flow patterns and particle collection efficiencies are examined for three different corona discharge electrode configurations, the spike tip locates at i) upstream, ii) downstream and iii) at both sides of the channel. The results show a complex and turbulent flow structure in the ESP with the spiked electrode. A pair of vortices is formed in the vicinity of the spiked electrode with the tip of the upstream-directed spikes, driving the main airflow toward the collecting plates and improving the collection efficiency of particles. Compared to the EHD secondary flow streamlines in the spike-plate type ESP one can deduce that the stronger vortices occur at higher Ehd/Re2 ratios. Furthermore, the distribution of deposited particles with the aforementioned spike tip locations reflected the real condition of particle deposition. The results help to improve the structural optimization of the spike-type ESP.