Sterilization efficacy of steam plasma flow at atmospheric pressure

Recently, it has bemome a social problem that the disease infection by the pathogenic microorganism spreads all over the world. Therefore, it is expected to establish an advanced sterilization method which has the advantages of simple configuration and ability to operate at atmospheric pressure. We studied the sterilization effects of the steam plasma flow at atmospheric pressure on bacteria. We developed a plasma source of the steam plasma flow at atmospheric pressure in a quartz tube of 8 mm in diameter and clarified its plasma characteristics and sterilization efficacy against Geobacillus stearothermophilus. A flow rate of the steam plasma flow of atmospheric pressure in a tube is 8.1 L/min which equals to the velocity of 2.7 m/s. When the applied voltage was 13 kV_PP and its frequency was 3 kHz, the discharge current of 62 mA and the discharge power of 30 W were observed. Under this condition, a good sterilization result of G. stearothermophilus was obtained for the sterilization time of 30 minutes.