Study on filtration performance of elliptical fiber with different arrangements

Jiawei Zhou,Liang Zhang,Wei Gong,Bo Zhang

doi:10.1177/1558925019893888

Jiawei Zhou, Liang Zhang + Show 2 more

Open Access

https://doi.org/10.1177/1558925019893888

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Abstract

The fibrous media composed of elliptical fibers is widely used owing to the high filtration efficiency. However, there are few studies on the arrangement of non-circular fibers, although the single non-circular fiber has been clearly investigated. In this article, two-dimensional numerical geometries of fibrous media with different elliptical fiber arrangements, namely, random distribution structure, dense–sparse structure, and bimodal structure, are developed for studying filtration performance. The results show that the large aspect ratio and solid volume fraction represent low particle penetration. When the particle diameter ( Dp) is small, the quality factor of bimodal structure is higher than the dense–sparse structure, especially at Dp = 50 nm. For the large Dp, the opposite is true. Meanwhile, reducing fiber diameter ( Df) is more significant than increasing solid volume fraction in terms of improving penetration. As for dense–sparse structure, replacing the elliptical fibers in sparse layers with circular fibers can comprehensively improve the quality factor of fibrous media. However, if the replacement between elliptical fiber and circular fiber occurs in dense layer, it will result in high quality factor at Dp ⩽ 500 nm, while low quality factor at Dp > 500 nm.

Highlights

For the past few years, respirable particulate matter, such as PM2.5, can cause harmful effects on the body’s respiratory system
In this article, four differently equivalent methods are proposed to predict the penetration per thickness and compare with corresponding elliptical fiber
Compared with other equivalent methods, the area-based circle can well predict the penetration of fibrous media composed of elliptical fibers

Summary

Introduction

For the past few years, respirable particulate matter, such as PM2.5, can cause harmful effects on the body’s respiratory system. Fotovati et al.[7] investigated the filtration performance of fibrous media with bimodal diameter distribution and showed the relationship between the quality factor and the quantity ratio of coarse/fine fibers. For accurately predicting the efficiency of fibrous media by interception and inertia collision, particle density released from the inlet is set as 2 ×106 / m based on the test results.[18] In this article, the inlet velocity (V = 0.04 m/s), equivalent fiber diameter (Df =5, 3, 2.5, and 2 μm), the SVF (7.5% and 10%), and AR (1.5, 2, and 3) are investigated.

Results

Conclusion