A Theoretically Based Mathematical Model for Calculation of Electrostatic Precipitator Performance

Abstract

A mathematical model is described which relates collection efficiency to precipitator size and operating parameters. Procedures are given for calculating particle charging rates, electric field as a function of position in wire-plate geometry, and the theoretically expected collection efficiencies for various particle sizes and precipitator operating conditions. Methods are proposed for empirically representing the losses in collection efficiency caused by non-uniform gas velocity distributions, gas by-passage of the electrified regions, and particle reentrainment due to rapping of the collection electrodes. Incorporation of these proposed techniques into a mathematical model of precipitator performance results in reduction of the theoretically calculated overall collection efficiencies. The reduced efficiencies are compared with those obtained from measurements on precipitators treating flue gas from coal-fired generating stations. The effects of changes in particle size distributions on calculated collection efficiencies obtained from the mathematical model are also presented.