Effect of gravity on particle collection efficiency of inertial impactors

This study has investigated the effect of gravitational force on particle collection efficiency in inertial impactors numerically and experimentally. In the numerical study, two-dimensional flow field in the inertial impactor was simulated by solving the Navier-Stokes equations with the control volume method. Particle trajectories were then calculated to obtain the collection efficiency at different Reynolds numbers, which are based on nozzle diameter. This study shows that gravitational force increases the particle collection efficiency when the Reynolds number is below about 1500. The numerical results were found to be in good agreement with the experimental data of Marple et al. (JAPCA, 37, 1303) (1987), Rubow et al. (American Industrial Hygiene Association Journal, 48, 532) (1987) and those obtained in the present study. (C) 2001 Elsevier Science Ltd. All rights reserved.