Corona Discharge Generated by Dual-Type Electrode Fixed Between Parallel Grounded Strips

Several electrode arrangements have been proposed to enhance the efficiency of insulating materials charging by corona discharge. Recent studies pointed out that the presence of a grounded metallic shield in the proximity of the high-voltage corona electrode increases, the total current measured at the surface of the collecting electrode decreases the corona onset voltage value and enlarges the reparation of current density and the surface potential as well. The aim of the present paper is to analyze the effect of replacing the shield by two parallel grounded strips located in the horizontal plan of the ionizing wire. The experimental results obtained show that the presence of the shield or the two parallel strips in the proximity of the dual wire electrode increases in the same way the corona current at the surface of the plate electrode. Varying the height of the strips and the wire-strips distance could modify significantly the behavior of the corona discharge in such electrode arrangements for both polarities. The characterization of this new electrode configuration could be very useful to the corona charging of different insulating materials in various electrostatic processes. These experiments are discussed in relation with the results of the numerical analysis of the electric field generated by the various electrode configurations. The equipotential lines plots and the electric field lines orientation explain the peculiarities of the corona discharge generated by this electrode arrangement.