Theoretical methods for computing electrical conditions in wire-plate electrostatic precipitators

Abstract

A new semi-empirical, approximate theory for predicting electrical conditions is described. In the approximate theory, analytical expressions are derived for calculating voltage-current characteristics and electric potential, electric field, and space charge density distributions. Comparisons of numerical and approximate solutions over a wide range of possible precipitator geometries and electrical operating points indicates that for practical purposes the approximate theory can be used in lieu of the more rigorous numerical theory. This saves large amounts of computer time and makes possible hand calculator usage. Recent in situ gaseous ion mobility data which are needed in the models are presented. For coal fired power plants, the reduced effective ion mobility in positive corona is found to be 1.6 times that for negative corona. Approaches for describing particulate space charge effects in the gas and electrical conditions in the collected particulate layer are briefly discussed.