OVERVIEW OF ELECTROSTATIC DEVICES FOR CONTROL OF SUBMICROMETER PARTICLES

The electrostatic precipitator (ESP) is the most widely used of a family of air pollution control devices that primarily exploit electrical forces in the control of particulate emissions. Others are the space-charge precipitator (SCP) (where the electric precipitation field is generated by the particles being collected), the self-agglomerator (SAG) (where oppositely charged particles are induced to agglomerate by the mutual force of attraction), the charged-droplet scrubber (CDS-I) (where drops charged to one polarity collect pollutant particles charged to the opposite polarity), charged-droplet scrubber (CDS-II) (where bipolar drops collect oppositely-charged fine pollutant particles), and charged-drop precipitators (CDP) (where fields generated by charged drops are used to precipitate like-charged fine particles onto electrodes). Using gas-residence time for effective cleaning as a dominant criterion, a broad overview of the relative merits of each of these systems in the control of submicrometer particles is given. The characteristic-time approach to interrelating diverse systems identifies the electrofluidized bed (EFB) as yet another configuration.