Separation of Microparticles by Size in an Electrodynamic Field

Abstract

The article studies electrodeposition in an electrodynamic field used, for example, in electrostatic filters for cleaning smoke from solid particles, as a method for separating micro- and nanoparticles by size. The dependence of the particle charge acquired in the corona discharge of a special electrode system, and hence the Coulomb force on their radius, allows spatially separating particles by size in a gas flow. A theoretically calculated curve of the dependence of the deposition length on the particle size in a channel equipped with corona-forming and precipitation electrodes is shown. By spraying micro- and nanoparticles into an air flow passing through a specially created precipitation channel, the dependences of the deposition length on the particle size were obtained, which are in good agreement with the calculated ones for microparticles. Separation of nanopowders failed, apparently due to the hindrance of proportional deposition of particles of different sizes by Coulomb forces by the ion wind, which has a complex vortex structure between the electrodes.