Three-dimensional ionic wind and electrohydrodynamics of tuft/point corona electrostatic precipitator

The flow interaction between the primary flow and the secondary flow (often called as an electric wind or ionic wind) in the wire-duct electrostatic precipitator (ESP) has been investigated theoretically and experimentally. In the past, the analysis was limited to the two-dimensional, which is acceptable only for the positive polarity. The negative corona, commonly used for the industrial ESPs, generates tufts along the corona wire and the point coronas on the discharge wire requires three-dimensional analysis. Three-dimensional electric field and space-charge density distributions, and the flow interaction between the primary flow and secondary flow, i.e., electrohydrodynamics were investigated. The computational results show that the secondary flow distribution consists of donuts-shape ring from each tuft or corona point, which was predicted by the first author 16 years ago. When the primary flow exists, a pair of spiral rings, like Goertler vortices is formed in the direction of the primary flow. The flow interaction was described using dimensionless number, N/sub EHD/, and the effects of particle motion in the electrohydrodynamic field in the tuft/point corona ESPs are discussed.