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FINE PARTICLE CHARGING DEVELOPMENT
Citation:
Pontius, D., L. Felix, J. McDonald, AND W. Smith. FINE PARTICLE CHARGING DEVELOPMENT. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/2-77/173.
Description:
The report gives results of theoretical and experimental investigations into the changing of fine particles by unipolar ions in an electric field, and evaluation of a specially designed small pilot-scale (600-1000 acfm) precharging device. Following an extensive review of the literature, a new theory was developed, predicting statistically the average charge per particle in a large collection of particles. The electrical mobility of particles charged under controlled conditions of ion density, charging time, electric field strength, and ion polarity was measured to determine the average charge per particle for comparison with the theory. Agreement between experimental results and theory was generally within 20%. The precharger evaluation, based on direct particle charge measurements and the effects on performance of a pilot-scale electrostatic precipitator of conventional design located downstream from the precharger, indicated that effective particle charging was achieved in accordance with the theoretical predictions. Particle migration velocities in the precipitator, with the precharger on, were up to 60% greater than with the precharger off.