Optimized Structure of Nano-Micro Composite Filter for Increased Filter Lifetime

MIN-SEON KWON, Myong-Hwa Lee, Kangwon National University, University of Miami

     Abstract Number: 245
     Working Group: Control and Mitigation Technology

Abstract
Air purifier generally utilizes disposable fibrous filter to remove fine dust. The performance of a fibrous filter used in an air purifier is evaluated by collection efficiency and pressure drop. Higher collection efficiency and lower pressure drop provide superior filtration performance. Electret filter collects particles not only by mechanical mechanisms such as diffusion, interception and inertia, but also by electrostatic attraction, resulting in higher filtration performance. Hence, electret filters are usually used in air purifiers. However, the filter should be periodically replaced as particles are deposited inside, leading to decreased dust collection efficiency by decreased electrostatic force and increased pressure drop by dust loading. Therefore, it is necessary to figure out how to increase filter lifetime by lowering the increment of pressure drop and maintaining the filter collection efficiency. Recently, many researchers have studied the nanofiber filters in order to improve the filtration performance of an air filter. However, nanofiber filters have the disadvantage of low dust holding capacity (the maximum dust amount that the filter can hold, DHC). Therefore, a nano-micro composite filter has been suggested as a potential way to decrease the increment of pressure drop and to improve filtration performance. In addition, it is expected that the filter lifetime can be different by stacking order of filter layers in a multi-layered filter. To validate this concept, the effect of stacking order of filter layers in nano-micro composite filters with three fiber layers on filter performance, pressure drop, and DHC by dust loading was investigated. In addition, the filtration properties of individual layer in uncharged and charged nano-micro composite filters were analyzed in order to quantify its pressure drop and DHC.

Acknowledgment
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. RS-2023-00249948).