TIME-DEPENDENCE OF NOX REMOVAL RATE BY A CORONA RADICAL SHOWER SYSTEM

In this paper, the effects of flue gas how rate and seed gas on the dy namics of corona discharge current-voltage characteristics and NOx rem oval characteristics are experimentally investigated for a corona radi cal shower system. The corona discharge current-voltage characteristic s have two operating modes which have a significant influence on NOx r emoval characteristics, where the threshold value of the treatment gas to seed gas flow rate ratio is about 8. The hysteresis of corona curr ent-voltage characteristics is observed in this system. For longer ope rational time, corona current and NOx removal rate significantly chang es with time. When the operation of the apparatus starts at relatively low applied voltage, the corona current under constant applied voltag e increases with time to reach a maximum value, then decreasing with t ime to reach a steady state. At this condition, high NOx removal effic iency can be achieved.