Time dependence of NO/sub x/ removal rate by a corona radical shower system

Abstract

In this paper, the effects of flue gas flow rate and seed gas on the dynamics of corona discharge current-voltage characteristics and NO/sub x/ removal characteristics are experimentally investigated for a corona radical shower system. The corona discharge current-voltage characteristics have two operating modes which have a significant influence on NO/sub x/ removal characteristics, where the threshold value of the treatment gas to seed gas flow rate ratio is about 8. The hysteresis of corona current-voltage characteristics is observed in this system. For longer operational time, corona current and NO/sub x/ removal rate significantly changes with time. When the operation of the apparatus starts at relatively low applied voltage, the corona current under constant applied voltage increases with time to reach a maximum value, then decreasing with time to reach a steady state. At this condition, high NO/sub x/ removal efficiency can be achieved.