Performance Evaluation of Plasma Air Cleaning Systems with Ion Impactor Type Electrodes for Removing Yellow Sand Dust

摘要

Yellow sand dust (Asian dust storm) causes harmful damage to both indoor and outdoor environments during the springtime. Removal of Yellow sand dust has become an issue for suitable indoor conditions, and an air cleaner is required to remove it efficiently; thus, an analysis of its chai^acteristics should be conducted. In this article, two types of plasma air cleaning systems based on the principle of electrostatic precipitation are evaluated using equivalent dust to Yellow sand dust. To study the influence of an electrode shape of precharger on the collection efficiency, we carried out experiments using a plate and an ion impactor type electrode. From the results, the discharge current was found to be higher for the ion impactor electrode than for the plate electrode. Also, the collection efficiency was greater with the ion impactor electrode than with the plate electrode. For the single-pass test, the removal efficiencies of Yellow sand equivalent dust at the face velocity of 1.0 m/s are greater than 80%) with the plate and ion impactor electrodes. For the multi-pass test in occupied spaces, the operation time required to reduce Yellow sand dust concentration from the initial concentration of 300-150 μg/m~3 (the criteria of indoor air quahty), is 5 min for the ion impactor electrode and 7 min for the plate electrode. Also, the clean air delivery rate (CADR) value is 113 for the ion impactor electrode and 85 for the plate electrode. The plasma air cleaning systems are suitable for the removal of Yellow sand dust for maintaining suitable indoor air quality.