310
Views
11
CrossRef citations to date
0
Altmetric
Original Articles

Calculation of the Charging Rate of Fine Particles by Unipolar Ions

&
Pages 168-172 | Published online: 13 Mar 2012
 

Abstract

Theories of particle charging based on boundary value solutions to the diffysional equation may not be applicable to electrostatic precipitators where the ion density is rarely more than an order of magnitude greafer than the particle concentration. A new charging equation, based on kinetic theory, is presented which evaluates the charging rate in terms of the probability of collisions between the flust particles and ions. In the presence of an external electric field, the surface of the particle is divided into three charging regions, and separate charging rates are calculated for each region. The total charging rate is the sum of these three individual rates. For large particles and high electric fields, this theory predicts essentially the same charging rate as the classical field charging equation of Rohmann and Pauthenier. For low electric fields, the theory reduces to White’s diffusional charging equation. Agreement is within 25% of Hewitt’s experimental results over the entire range of variables where data are available. For practical charging times, agreement is within 15%.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.