# Analysis of Plasma Ion Distribution and Dust Collection Efficiency of Carbon-Brush Air Purifiers
###### Abstract  
In recent years, many studies on air purifiers have been conducted, as particulate matter and virus issues have emerged. In this study, the ion concentration distribution in an air purifier that applies a high voltage was investigated through simulation. For a single carbon brush that applied a high voltage of -8.5 kV, the simulation results of the ion concentration distribution in the ground direction were compared with the result of the experiment and an error of 4.3% was observed, thereby confirming the reliability of the simulation. On this basis, the ion concentration distribution was calculated according to the number and location of the brushes. In addition, the charging number was calculated by applying the charging mechanism to the distributed dust particles, and the dust collection efficiency was calculated by conducting particle multiphysics analysis. The dust collection efficiency increased from 0.5% to 1% as the number of brushes increased, and the dust collection efficiency was 82% when there were two brushes and 83% when there were four brushes. In the proposed modeling, the location of the brushes is more important than the number of brushes. These results are expected to provide more accurate design information for the number and location of brushes applicable to an air purifier. computational fluid dynamics (CFD); carbon-brush; collection efficiency; air-purifiers; ion concentration +
Footnote †: journal: Applied Sciences  
optimization conditions in a corona discharge static eliminator. As a result, the equation was derived under the AC application conditions, and the characteristics of the voltage difference between AC and DC were identified [15; 16]. [PERSON] et al. conducted an experimental study on improving dust collection efficiency by analyzing the efficiency of an activated carbon filter according to the increase in ions and the dust collection efficiency according to the intensity of the electric field. As a result, the antibacterial performance and dust collection efficiency of the ionizer were secured, and the possibility of a high-efficiency multifunctional air purifier was experimentally secured [17; 18]. You conducted an experimental study on improving the dust collection efficiency of an ionizer by analyzing the pressure loss according to the flow velocity and collector. As a result, it was possible to increase the efficiency of fine dust particles by introducing the dielectric and ionizer method, and to obtain the possibility of large-capacity gas processing and high-efficiency device miniaturization with low pressure loss at a high flow rate [19; 20]. [PERSON] measured the ozone concentration according to the applied voltage in an air purifier that applied carbon brushes, and experimentally analyzed the dust collection efficiency according to the number of brushes. As a result, the correlation between the number of carbon brushes, voltage, and ozone was derived, and the indoor air purifier standards of the Korea Air Purifier Association were satisfied [14]. [PERSON] et al. conducted a study on a PM collector to which high-capacity ESP was applied for toxicity research. At a flow rate of 75 lpm and an applied voltage of +12 kV, they achieved particle collection efficiency of more than 80% for almost all particles with a size range of 0.015-2.5 \(\upmu\)m, while the ozone concentration was 17 ppb [21]. [PERSON] et al. developed a new method to generate particulate matter in an inhalation exposure study. In order to investigate particulate matter properties, PM sources that are physically and chemically stable over a wide range of processes were generated [22]. In addition, recent studies have been conducted studies on the spread of harmful particles such as COVID-19 and the effects of pollutant exposure [23; 24]. Most of these studies conducted experimental studies on the generation method and collection efficiency of ions in the purifier.