Abstract
A DC corona reactor using electron attachment is utilized to remove dilute fluorocarbon in an air-conditioning unit or SF6 in a gas circuit breaker. By employing helium gas to purge the low concentrated gas in the unit, corona onset voltage in the corona reactor decreases. We observed the characteristics of corona discharge for the pure helium gas with flow and for the helium gas contained dilute SF6 gas at atmospheric pressure. In pure helium gas, luminous spots appeared along the discharging wire. The number of luminous spots without gas flow increased stepwise with the discharging current. In contrast, the luminous spots decreased as the gas flow rate increased. In the helium gas containing dilute SF6, corona discharge occurred uniformly along the discharging wire initially. As the time elapsed, the discharge aspects drastically changed: The discharge voltage gradually decreased to that in the pure helium gas and the uniform corona discharge along the discharging wire changed to a single spot.
