Electrical neutralization of charged aerosol particles by bipolar ions

Abstract

The electrical neutralization of charged aerosol particles by bipolar ions in a flow-type chamber was studied theoretically and experimentally. The time-dependent changes in electrical charge of aerosol particles were evaluated by numerically solving the “birth-death” equation under various conditions. The calculated results were arranged using dimensionless parameters, and the necessary conditions for charged particles to attain equilibrium charge distributions were clarified. The graphs presented in this paper enable one to estimate the minimum concentration of bipolar ions required to neutralize the charged particles under various conditions. Some of these results are found to agree with experimental results obtained by means of the visual technique in the measurement of particle size and electrical mobility. © 1983, The Society of Chemical Engineers, Japan. All rights reserved.