Investigating the influence of local porosity variations and anisotropy effects on the permeability of fibrous media for air filtration

Abstract

International audienc

Prediction and Optimization of Interlayer-Interface Resistance for Expanded Polytetrafluoroethylene-Laminated Polyphenylene Sulfide Composite Membranes

“…Therefore, the normalized frequency function was used to calculate the average pressure drop to consider the effect of fiber orientation on the pressure drop. 37,39 Spielman and Goren's 2D random in planes parallel to flow model (eq S. 13) is calculated by eq 6.…”

“…In this case, the fibers were all in planes parallel to the airflow direction, but had random angles in the 2D planes, which meant that the fiber arrangements were between the perpendicular and parallel arrangement. Therefore, the normalized frequency function was used to calculate the average pressure drop to consider the effect of fiber orientation on the pressure drop. , Spielman and Goren’s 2D random in planes parallel to flow model (eq S.13) is calculated by eq . where A and B are the weight coefficient of the perpendicular and parallel fiber orientation, and their sum is 1; f ⊥ (ε) is the perpendicular fiber orientation model; f ∥ (ε) is the parallel fiber orientation model. In eq S.13, A and B are both 0.5 .…”

“…In eq S.13, A and B are both 0.5 . Similarly, for the existing Happel’s model, substituting eqs S.4 and S.5 into eq is done to obtain a novel Happel’s fiber orientation model between perpendicular and parallel arrangements, where A and B are both 0.5 because PPS fiber felt is obtained through the needle fabrication. , The results are as follows: …”

Preparation and Characterization of Electrospun PAN-CuCl2 Composite Nanofiber Membranes with a Special Net Structure for High-Performance Air Filters

“…Unlike the tortuous pore structure constructed by densely packing substantial amounts of fibers, the net structure grows between the nanofibers, and a large number of fine nanofibers increases the effective area of the pore and generates a smaller pore size, which is much smaller than the pore between the nanofibers. Additionally, with the CuCl 2 doping concentration increasing, the net structure disappears, and the pore diameter becomes larger, favoring the airflow through the membranes [ 31 , 35 , 36 ].…”

Fabrication and characterization of a novel konjac glucomannan-based air filtration aerogels strengthened by wheat straw and okara

“…The filtration resistance was continued to decrease until below 50 Pa when wheat straw concentration ≥0.5% (w/v). Air permeability is also an important indicator of filter materials, affecting the filtration efficiency of filter materials (Woudberg, Theron, Lys, & Le Coq, 2018). The air permeability of aerogel with wheat straw addition is shown in Fig.…”