Reduction of Ozone Generation and Durability of Discharge Electrode in an Electrostatic Precipitator With Carbon Brush Disk Electrode

Air cleaners are required to collect particles of nano to micro-order size due to the air pollution and the pandemic of novel viruses. One example of the air cleaners is an electrostatic precipitator (ESP) using a corona discharge, which has high collection efficiency for the airborne particles. However, the corona discharge generates ozone, which is harmful to the human body. Therefore, it is necessary for ESPs to reduce the ozone concentration. Therefore, the aim of this study is to achieve high collection efficiency greater than 95% at a low ozone concentration and investigate the durability of the discharge electrode in an ESP with a carbon brush disk electrode. Its collection efficiency and durability were compared to those of a previous ESP with a knife edge disk electrode. As a result, the collection efficiencies at the knife edge and the carbon brush disk electrodes were greater than 99% and 95% at an ozone concentration of 0.02 ppm, respectively. However, the ozone concentration at the knife edge disk electrode, which was made of carbon steel and tungsten, increased to greater than 0.1 ppm at an elapsed time of 25 hours due to electrode deterioration. On the other hand, the cemented carbide disk electrode and the carbon brush disk electrode maintained high collection efficiency and low ozone concentration for 150 hours.