Design and performance evaluation of a small unipolar aerosol charger system

Abstract

A small unipolar aerosols charger system is designed by using corona discharge technology. The performance is evaluated and calibrated in this paper. This system has two main components, one is the corona discharge which adopt tip - arc structure, and the another is high voltage constant current control circuit based on the weak current feedback adjustable as the corona current control part, which ensure that ion concentration remain stable in the process of discharge. The experimental results show that negative corona discharge is better than the positive corona discharge in the same discharge corona current. The intrinsic charging efficiency get better with corona current increases, which can as high as 99% when the negative discharge corona current is 3 μ A. However the extrinsic charging efficiency change with corona current change, it got the best performance in the corona current 1.5μ A at different particle size in this paper. This small and simple design of the unipolar charger system is suitable for portable aerosol classifier based on electrical mobility techniques.