Kinematic Coagulation of Charged Droplets in an Alternating Electric Field |
| |
| Authors: | Kari E. J. Lehtinen Jorma K. Jokiniemi Esko I. Kauppinen Jukka Hautanen |
| |
| Affiliation: | 1. Technical Research Centre of Finland (VTT), Aerosol Technology Group , P.O. Box 1401, VTT, VTT Energy, (K. E. J. L.;2. J. K. J.), SF-02044, Finland;3. VTT Chemical Technology , P.O. Box 1401, VTT, VTT Energy, (E. I. K.), SF-02044, Finland;4. Tampere University of Technology , P.O. Box 692, SF-33101, Tampere, Finland |
| |
| Abstract: | An analytic-numerical model has been developed to study kinematic coagulation caused by the vibrational motion of charged particles in an alternating electric field. The primary aim of this study was to find out the reduction in the number concentration of fine particles of diameter 0.1 μm-1.0 μm caused by collisions with larger, supermicron particles. Three cases are considered: (1) unipolar charging, (2) fine particles are neutral, and (3) fine particles and large particles have opposite polarity. We find out that in cases 1 and 2 the rate of kinematic 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/m3. In the former, where the mass median diameter is 3.0 μm, we discover a 20%-50% reduction in number concentration of particles in the range 0.5–1.0 μm and less significant reduction in smaller particles. The latter (MMD = 6.0 μm) represents power plant conditions. In this case the reduction varies from 10% (0.1 μm) to 95% (1.0 μm). |
| |
| Keywords: | |
|
|
