Effect of free electrons on nanoparticle charging in a negative direct current corona charger

Abstract

A two-dimensional numerical model is proposed in this letter to take into account the effects of free electrons on nanoparticle charging in a negative direct current wire-tube corona charger. Numerical results are in excellent agreement with the experimental data by using a capturing probability of electrons onto nanoparticles with a value of 0.013. These free electrons contribute greatly to the charging efficiency at high products of mean ion concentration and mean residence time, which explains very well the large discrepancy found in earlier models that considered only negative ions. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2967470]