Distribution of electric field strength around a large-scale charged particles cloud

To investigate an electrical discharge occurring from or in a space charge cloud, a large-scale charged particles cloud was formed by using a cloud generator consisting of a blower and corona charger. The distribution of the electric field strength around a charged particles cloud has been investigated to determine the behavior of charged particles. The soil conditioning particles were charged by corona charging and blown by high-speed air flow in a test room, 5 m in wide, 10 m in length and 3 m in height. The charge-to-mass ratio of the particles blown by this method was 170 /spl mu/C/kg. While the electric field strength at the outside of the cloud increased up to 52 kV/m within 2 m from the cloud generator, it decreased below 25 kV/m farther than 2 m away from the cloud generator due to dispersing motion of charged particles. The change in the electric field strength due to dispersing motion of charged particles can be qualitatively explained by a simple cloud model. The velocity of charged particles transported by air flow and mobility of charged particles are found to be effective factors to increase the electric field strength around the large-scale charged particles cloud.