Operating regimes of corona and silent discharges in coaxial cylindrical reactors

Abstract

The physical mechanisms of the electrical discharges formed in coaxial cylindrical reactors have been investigated in this paper under different operating conditions for the reactors. The reactors were fed by natural air flowing with a constant rate at atmospheric conditions and stressed by an ac voltage. The wave form of the ac voltage applied to the reactors has been studied corresponding to the discharge current, over the whole range of the operating conditions. The results have shown that the operating conditions for the reactor modify the physical mechanism inside it in the form of either corona or silent discharges or spark over. The onset voltage of the different electrical discharges formed inside the reactors has agreed with Peek’s equation, whatever the operating conditions. Subsequently, empirical equations concerning the operating conditions for the reactors have been derived by using Peek’s and Townsend’s equations. The derived equations represent suitable criterions to predict the different types of the electrical discharges that will form inside the reactors under any operating conditions. The results have been illustrated by recorded oscillograms showing the wave form of the ac voltage applied to the reactors and the corresponding current pulses.