Numerical study on the effect of staggered wire electrodes in an electrostatic precipitator

Abstract

In this paper, a numerical model is developed to describe the wire-plate electrostatic precipitator used in industrial application for air cleaning. The complex interactions between fluid dynamics, electric fields and particle dynamics are considered. Therefore, the combined Eulerian and Lagrangian approach is used in this study. In order to describe corona phenomena around high voltage electrode, electric field and ion current density field in electrostatic precipitator are numerically calculated using the iterative method for corona discharge model suggested by Kim [1]. The charging model suggested by Lawless [2] is used for the charging phenomena of particles by corona discharge because it was designed to predict combination effect of diffusion charge and field charge. The numerical model in this study is implemented by UDF in commercial software FLUENT and validated with experimental and numerical results from literatures. The effects of wire arrangement on electrostatic precipitator characteristics are investigated. Both inline and staggered arrangements of wire electrode have been considered for fixed value of gas velocity equal to 2 m/s. Applied voltage on wire electrode is varied in the range of 6 to 13 kV and particle diameter is 4 µm. For low voltage condition, staggered arrangement of wire electrode caused the turbulent effect so that the collection efficiency increases more than inline arrangement. However, the collection efficiency decreases in high voltage condition because electric force applied on particles passing between the wire electrodes is canceled out by both side wire electrodes.