Corona discharge characteristics of narrow coaxial wire- pipe discharge tubes with gas flow

Abstract

An experimental investigation has been conducted to study corona discharge in a narrow tube. Narrow or capillary corona discharge (dis- charge tube diameter d = 1 to 20 mm) is used for many industrial applications such as flue gas cleaning corona induced plasma reactors, ion sources and electrohydrodynamic heat exchangers. In this work, corona discharge characteristics of narrow coaxial wire-pipe discharge tubes with gas flow are experimentally investigated. The results show that, unlike normal corona discharge, a hysteresis in the corona discharge current-voltage characteristics were observed for narrow tube discharges. The on-set of the corona discharge observed to be significantly depends on the gas temperature and gas flow rates 1.588 cm 0.d. copper tube was placed coaxially outside the system. Entrance and exit gas temperature of the wire-pipe corona discharge zone and outer-grounded pipe gas cooling zone were measured by T-type thermocouples. Time-averaged current was measured by the Keithly electrometer, and air flow rate in both flow channels was measured by a rotameter. The air flow flowing through the corona discharge zone was electrically heated at upstream of the system. Experiments are conducted for the gas flow rate from 0 to 20 [/min., the inlet gas temperature from 10 to 60°C, and the applied voltage from 0 to It 10 kV