Improvement of NOx Removal by Silent Discharge in Acoustical Standing Wave Field

Abstract

The purpose of this study is to discuss the effects of sound wave on discharge and NOx removal. Against this backdrop, we removed NOx from NO/N₂ mixed gas by superimposing silent discharge and sound wave in an acoustical standing wave field. As the results, NO removal rate and efficiency increase with increasing sound pressure. In particular, highest NOx removal rate is obtained when the electrode is located at the node point of sound pressure distribution, that is, at the maximum point of the particle velocity. This result shows significant improvement on NO removal by superimposing silent discharge and sound wave. Furthermore, NO removal rate decreases with increasing resonance frequency, for the reason of decreasing amplitude of particle displacement. Therefore, it is considered that NO removal rate relates to particle velocity and amplitude of particle displacement.