Electrostatic particle collecting apparatus

摘要

Apparatus for charging and collecting submicron particles. The particles are charged by a needle-to-plate ionizer having offset rows of needles which are spaced from the plate such that voltage gradients of 6 KV/cm and higher are achieved. Needle-to-needle spacing and effective area of the plate are such that a corona current having a density of at least 4 ma/m2 flows between the needles and the plate. Charged particles are collected in a collecting section having a deflector electrode and a pair of collecting plates. The deflector electrode includes a conductor embedded in a dielectric material having a dielectric constant greater than 1, which dielectric material suppresses arcs between the deflector electrode and the collecting plates. Baffles are provided to collect efficiently and with low pressure drop those charged submicron particles not collected on the collecting plates.