Experimental Study of Corona Discharge Generated in a Modified Wire-Plate Electrode Configuration for Electrostatic Process Applications

Parallel wire-plate electrode arrangements are widely used to generate corona discharges in various electrostatic processes. This paper analyzes the characteristic features of a slight modification of such an electrode configuration. In all the experiments, a stainless steel wire of diameter 0.18 or 0.57 mm was used as the corona electrode, energized from a reversible dc high-voltage supply. The modified two-level grounded electrode consisted of three metallic plate segments, which are parallel to the wire and located at 20, 15 (or 10), and 20 mm from it, respectively. In a first set of experiments, the current-voltage characteristics of this electrode arrangement were obtained for both polarities of the high-voltage supply and compared to those of a standard wire-plate electrode system. In a second set of experiments, two of the plate segments were made of several aluminum strips insulated from each other and successively connected to a microammeter, in order to characterize the distribution of the corona current at the surface of the modified grounded electrode. The third set of experiments described in this paper was performed with the corona electrode energized from a rotary spark gap connected at the output of the dc high-voltage supply. Finally, the possibility of applying this modified electrode configuration for the precipitation of dust contained in flue gases is briefly discussed.