Correlation between the EHD flow and the collection efficiency of an ESP

摘要

In this paper, particle velocity fields inside a wire-to-plane ElectroStatic Precipitator (ESP) are investigated experimentally using Particle Image Velocimetry (PIV). The main objective of this study is to analyze the effect of the ionic wind on the particle collection efficiency in such systems. The high voltage power supply waveform and the presence of a dielectric barrier are the major parameters taken into account. The submicron particles, with a mean size of about 0.3 m, are generated from incense burning and introduced into the ESP in order to examine the collection efficiency of the ESP using an aerosol spectrometer. PIV results show a strong interaction between the primary flow and the secondary flow (ionic wind). Near the wire electrode, the strong electric forces moved the particles from the central part of the channel to the plate electrodes. Within the drift region, the velocity magnitude depends essentially on the balance between the electric and the viscous forces. As expected, the highest collection efficiency is obtained with the negative dc corona. At low frequency (< 30 Hz), the Dielectric Barrier Discharge (DBD) is as effective as the positive dc corona. Correlation between the ElectroHydroDynamic (EHD) flow and the collection efficiency show that the optimum distribution of ionic wind in time and space is one solution for the improvement of electrostatic precipitation of submicron particles.