KINEMATIC COAGULATION OF CHARGED DROPLETS IN AN ALTERNATING ELECTRIC-FIELD

An analytic-numerical model has been developed to study kinematic coag ulation caused by the vibrational motion of charged particles in an al ternating electric field. The primary aim of this study was to find ou t the reduction in the number concentration of fine particles of diame ter 0.1 mu m-1.0 mu m caused by collisions with larger, supermicron pa rticles. Three cases are considered: (1) unipolar charging, (2) fine p articles are neutral, and (3) fine particles and large particles have opposite polarity. We find out that in cases 1 and 2 the rate of kinem atic coagulation in negligible and in case 3 significant. The results are demonstrated with two sample calculations with total mass loadings of 2 and 20 g/m(3). In the former, where the mass median diameter is 3.0 mu m, we discover a 20%-50% reduction in number concentration of p articles in the range 0.5-1.0 mu m and less significant reduction in s maller particles. The latter (MMD = 6.0 mu m) represents power plant c onditions. In this case the reduction varies from 10% (0.1 mu m) to 95 % (1.0 mu m).