Simulation and measurement of particle trajectory in an electrostatic precipitator with multiple wire electrodes

Abstract

The purpose of this study is to show the validity of the simulation result for particle charge and trajectory in an ESP with multiple wire electrodes.The ESP in this study has wires-and-plates configuration composed of three high-voltage application wire electrodes placed between grounded plate electrodes with a gap of 15 mm. The potential, the electric field intensity and the negative ion density were calculated by coupled analysis of Poison’s and current- continuity equations. The fundamental equation of flow field considering the ionic gas flow was a k-ω turbulence flow model. The charge of the particles was calculated from the differential equations of the electric and diffusion charging equations, taking into account the temporal and spatial electric field and ion density. The charged particle trajectory in the ESP was analyzed by an equation of motion considering fluid drag force and Coulomb’s force. In the measurement of the charged particle trajectory, oil mist as the tracer particle was mixed into the gas flow, and analyzed by a particle image velocimetry (PIV) using the software.As a result, the analysis value of the current density distribution on the surface of the grounded plate electrode agreed with the experimental value. The analysis results of the particle trajectory showed that the particle velocity increased, and moved toward the grounded plate electrode as the discharge power increased. The x and y components of particle velocity measured using PIV almost agreed with the simulated result. These results indicated the validity of the simulation result for charged particle trajectory, which was calculated by fitting the analyzed corona current to the experimental value, in the gas flow considering the ionic flow in an ESP with multiple wire electrodes.