Estimation of the agglomeration coefficient of bipolar-charged aerosol particles

Electrostatic agglomeration is a promising method for improving the submicron particles' collection efficiency of an electrostatic precipitator. The electrostatic agglomeration coefficient of bipolar charged particles is calculated using a two particles collision model to evaluate the effect of external electric field on the particles agglomeration. The model is based on kinetic equations which trace the trajectories of two particles under an external electric field, Coulomb's force, image force and air viscocity. As an agglomeration nucleus for submicron dust particles, a solid carbon particle and a water droplet are investigated. The calculated coefficients show that an AC electric field with low frequency is very effective for bipolar-charged particles agglomeration. In particular, water droplet gave a large agglomeration coefficient due to its large dielectric constant. (C) 2000 Elsevier Science B.V. All rights reserved.