Particle charging apparatus and method of charging particles

摘要

A method for charging of aerosol particles includes providing a charger housing having a longitudinal axis extending between an inlet and an outlet of the charger housing with a stream of aerosol particles flowing parallel to the longitudinal axis from the inlet to the outlet. A confined electric field is created within the housing parallel to the longitudinal axis for directing a stream of unipolar ions to flow parallel to the longitudinal axis of the charger housing towards the outlet for use in charging the stream of aerosol particles. To further reduce charged particle loss within the charger housing, a clean sheath may be created between the stream of aerosol particles and the charger housing, an outlet electric field may be created proximate the outlet of the charger housing such that charged particles are forced towards the longitudinal axis, and/or the stream of aerosol is contracted proximate the outlet of the charger housing forcing the charged particles toward the longitudinal axis. Apparatus for carrying out the method is also described.