Numerical Modeling of Nanoparticle Collection Efficiency of a Single-Stage Wire-in-Plate Electrostatic Precipitator

Guan-Yu Lin (1), CHUEN-JINN TSAI (1)

(1) Institute of Environmental Engineering, National Chiao Tung University

     Abstract Number: 473
     Last modified: May 12, 2010

Abstract
The numerical models for predicting collection efficiency of particles in the size range of 0.3~10.0 micrometer in the ESPs have been well developed. However, for nanoparticles, or particles with the diameter below 100 nm, the existing models can’t predict the collection efficiency very well. In this study, a 2-D numerical model was developed to predict the nanoparticle collection efficiency in single-stage wire-in-plate electrostatic precipitators (ESPs). Laminar flow field was solved by using the Semi-Implicit Method for Pressure-Linked Equation (SIMPLER Method), while electric field strength and ion concentration distribution were solved based on Poisson and diffusion-convection equations, respectively. The charged particle concentration distribution and the particle collection efficiency were then calculated based on the convection-diffusion equation with particle charges calculated by Fuchs diffusion charging theory. The simulated collection efficiencies of 6-100 nm nanoparitcles were compared with the experimental data of Huang and Chen (2002) for a wire-in-plate dry ESP (aerosol flow rate: 100 L/min, applied voltage: -15.5~-21.5 kV). Good agreement was obtained. The simulated particle collection efficiencies were further shown to agree with the experimental data obtained in the study for a wire-in-plate wet ESP (aerosol flow rate: 5 L/min, applied voltage: +3.6~+4.3 kV) using monodisperse NaCl particles of 10 and 50 nm in diameter. It is expected that model can be used to facilitate the design of ESPs for nanoparticle control, and electrostatic nanoparticle samplers.