Deposition of Charged Aerosol Particles Flowing in a Cylindrical Tube

Abstract

Deposition of unipolarly charged particles by their own space charge from laminar flow in a cylindrical tube is investigated both experimentally and theoretically. Experimental deposition efficiencies for fly-ash particles agree well with Wilson's analytical solutions. The distribution of the deposited mass of particles in an axial direction in a brass tube is also well predicted by Wilson's equation. The polarity of charged particles has no effect on the deposition efficiencies. It is also found that the size distributions of deposited particles are almost the same for any axial position in the tube. This experimental fact shows that the deposition efficiencies are independent of the particle size, which is also predicted by Wilson's equation in so far as the field charging is predominant. Effects of the particle inertia, Brownian diffusion and image force are also discussed, showing that the effects of these physical phenomena on the deposition of charged particles are negligible in the experimental range.