Effect Of Filter Structure Research Articles

Experimental and CFD analysis of fluid flow through nanofiber filter media

This work presents a novel approach to investigating the slip effect in nanofiber filter media. Electrospun nanofiber media with high efficiency and low pressure drop were produced at different concentrations and durations. The surface and cross-sectional morphology of nanofiber media were studied using FE-SEM. Fiber orientation and diameter distributions were also examined. The 3D virtual nanofiber media was modeled using this information along with the experimentally measured porosity and thickness of the media. The effect of the slip phenomenon in nanofiber media was studied numerically, and the results were compared to experimental data. Excellent agreements were found between the measured and simulation results. Additionally, filtration simulations considering aerosols injected with airflow through the nanofibrous filter media were conducted by considering the slip effect, and the effect of filter structure on filtration performance (removal efficiency and pressure drop) was investigated.

Effects of filter structure, flow velocity, particle concentration and fouling on the retention efficiency of ultrafiltration for sub-20 nm gold nanoparticles

Ultrafiltration techniques with membranes of pore sizes under 100 nm have been widely applied in drinking water, wastewater, semiconductor and pharmaceutical process water treatments for nanoparticle (NP) and pathogen removal. The most direct way to evaluate the membrane performance is to experimentally obtain the size fractional retention efficiency. However, the real-life performance of the membrane in terms of fouling (or loading) characteristics and the effects of the concentration of challenging particles and rate of flux (or filtration velocities) on the filtration efficiency during fouling have not been well understood. In this study, systematic filtration experiments for filtration efficiency at clean and loaded conditions were conducted for three different 50 nm rated membrane filters, including PTFE (Polytetrafluoroethylene), PCTE (Polycarbonate Track-Etched) and MCE (Mixed Cellulose Ester) membranes, against 5, 10 and 20 nm Au NPs at different feed concentrations and fluxes. The results showed that the effects of feed concentration and flux are significant. This study provides important insights of retention mechanisms and efficiency for different ultrafiltration membrane structures at varied filtration velocities and fouling characteristics giving clear directions of future NP ultrafiltration research.

Depth filtration of nanoparticles: Effect of filter structure, flow velocity, and loading

Depth filtration of nanoparticles: Effect of filter structure, flow velocity, and loading

Lattice-Boltzmann flow simulation of an oil-in-water emulsion through a coalescing filter: Effects of filter structure

The permeation of an oil-in-water (O/W) emulsion through a coalescing filter was numerically studied using the lattice Boltzmann method (LBM). A numerical simulation model for the coalescing phenomena was developed based on the free-energy LBM. We investigated the effects of the wettability of fibers, filter porosity, and fiber diameter on the coalescing behaviors by performing two-dimensional permeation simulations for the O/W emulsions through modeled fibrous filters. We mainly focused on hydrophilic filters because they did not generate small secondary droplets during oil droplet detachment from the filter, and this is preferred for precise separation of oil and water. Our simulations demonstrated that filters with larger pore spacings enable formation of larger droplets but allow more droplets to pass without coalescing. To solve this problem, we designed bi-layered filters composed of a small-pore filter to accurately catch the droplets and a large-pore filter to enlarge the droplets; we demonstrated the effectiveness of the bilayer structure for membrane coalescence.

Electrostatically Enhanced Stainless Steel Filters: Effect of Filter Structure and Pore Size on Particle Removal

The goal of this study was to investigate the effect of using stainless steel fibrous and porous filters as the ground electrode of a point-to-plate electrostatic precipitator on particle penetration. The effect of filter medium structure and pore size on particle removal has been investigated as a function of particle size for particles in the range of 0.03 to 1 w m and filter face velocities in the range of 15 to 75 cm/s. Furthermore, the effect of filter thickness on penetration reduction was investigated in order to develop a better understanding of the relationship between the filtration depth, filter face velocity, and particle size for each filter. Seven different filters were tested. Four of the filters were made of 316L SS sintered metal fibers and three were made of 316L SS metal powders. The pore sizes of these filters ranged from 6 w m to 100 w m. The application of the electrical field decreased particle penetration by a factor of 6 to 54, depending on filter type and filtration velocity, wit...