Air Plasma Sterilizer Using a Parallel Dielectric Barrier Discharge

Abstract

Air sterilizer is one of the essential components in combating the Covid-19. A wind tunnel model of the air sterilizer using a dielectric barrier discharge plasma is proposed to destroy the virus by direct contact with the plasma. Dangerous ozone production in the plasma reactor should be controlled to a safe level. Two parameters affecting the ozone concentration, i.e., electrical power and airflow, were investigated. The DBD reactor was a cell constructed from an array of alternate electrodes. The plasma was generated by an AC high voltage generator with a range of 2kV -3kV. The power and the high voltage were varied by controlling the DC input voltage of the generator. The airflow was varied by controlling the speed of an exhaust fan from 0.5 m/s to 3.0 m/s. The state was characterized using optical emission spectroscopy in the range of 200 nm – 1000 nm. The results showed that both parameters played a significant role in ozone concentration. The trend of the ozone is strongly correlated with the OH species, which reacts with oxygen. The highest ozone concentration of 4.51 ppm was observed at the DC voltage around 19 volts or the power of 34.2 watts. However, a decrease of the ozone concentration at a voltage higher than 19 volts related to 2.9 kV was observed. In general, the data showed that faster airflow decreases ozone concentration. A drastic decrease of the nitrogen species sustaining the plasma occurred at the airflow higher than 2 m/s.