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

Parallel wire-plate electrode arrangements are widely used to generate corona discharges in various electrostatic processes. The present paper analyzes the characteristic features of a slightly-modified such electrode configuration. In all the experiments, a stainless steel wire, diameter 0.18 mm or 0.57 mm was employed as corona electrode, energized from a reversible DC high-voltage supply. The grounded electrode consisted in three plate segments, parallel to the wire and located respectively at 20 mm, 15 (or 10) mm, and 20 mm from it. 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, each plate segment was made of several Aluminum strips insulated from each other and successively connected to a micro-ammeter, in order to characterize the distribution of the corona current at the surface of the grounded electrode. The third set of experiments described in the 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 to apply this electrode configuration for the precipitation of dust contained in flue gases is briefly discussed.