Effect of Room’s Temperature and Electrode Gap on Current of Negative Corona Discharge in Rod-Plane Electrode Configuration

Abstract

The stable corona discharge is widely used in filtration and electrostatic separation in recent years, and several models have been used by researchers to analyze one of its most important properties which is the current-voltage characteristic. The aim of this paper is to investigate the influence of ambient temperature and electrodes’ gap on negative DC discharge using rod-plane geometry, and the Townsend formula was found to be most appropriate model (I=K.V.(V-V0)). The experimental results show that for the same voltage level applied to the high voltage electrode, the discharge current rises with increasing temperature and decreases as the electrodes’ gap increases. Using curve fitting, it was proven that the geometric factor K is proportional to temperature and to the power of the distance between electrodes independently, and the threshold voltage V0 is proportional to the product of the temperature reciprocal and the power of the inter-electrode spacing. From these results, a new modified Townsend formula by introducing the air temperature and the distance between electrodes is proposed to calculate the discharge current with an accuracy of ±10%.