10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
The Effect of Fiber Polydispersity on Filtration Modeling
SEUNGKOO KANG, Da-Ren Chen, David Y. H. Pui, University of Minnesota
Abstract Number: 769 Working Group: Aerosol Modeling
Abstract Fibrous filters are widely used to remove aerosol particles. To design a filter with desirable filter structures and properties, estimation of filtration performance of fibrous filter media is essential. A majority of studies have modeled computational filter domains with uniform-sized fibers, i.e. the domain is composed of monodisperse fibers, while real fibrous filter media are composed of polydisperse fibers. In this study, a filtration domain composed of randomly distributed polydisperse fibers is presented with its properties, such as the thickness and solidity, the same as the real filter media. In the modeling, the collection efficiencies of filters were obtained from the numerical model using particles in the size range from 3 to 500 nm, and these efficiencies were compared to the efficiencies from experimental data. In addition, the collection efficiencies from computational domains with uniform-sized fibers were also compared in order to investigate the effect of fiber polydispersity. It was found that collection efficiencies are significantly affected for the domain with monodisperse fibers depending on the fiber size and filter types, while the domain with polydisperse fibers showed an excellent estimation of efficiencies regardless of filter types. Via the validated model, we also examined the effect of fiber polydispersity on the collection efficiency for domains having the same arithmetic mean fiber diameter and properties such as solidity and thickness. Results showed that the particle collection in filter media is affected by the degrees of fiber polydispersity, especially for particles in the size range between 10 and 100 nm. For fibrous filters having bimodal size distributions, the collection efficiency was influenced by the degrees of fiber polydispersity and the size and volume fraction in each fiber mode.