The paper focuses on two particular phenomena which contribute to the poor collection efficiency of fine particles (from ~ 0.1 µm to ~ 2 µm) by electrostatic precipitators (ESPs). Firstly, the influence of turbulence on collection rate is considered as well as the fact that the charged fine particles are expected to give the main contribution in the generation of small eddies in ESPs. Experiments on collection efficiency η of cigarette smoke show that η decreases as the dust concentration is increased, due to the subsequent increase in eddy diffusivity. The second phenomenon observed in the study is the deagglomeration of agglomerates in the ESP. An agglomeration process occurs, which is more and more marked as the smoke concentration is raised. Once charged in the ESP, some of the agglomerates disintegrate under the Coulomb repulsion, which leads to an apparent collection efficiency strongly depending on the particle size.

Keywords: Electrostatic precipitation, Fine particles, Electrohydrodynamics (EHD), EHD turbulence, Electrical disintegration of aggregates