Filtration performance evaluation

Tewari PK, Singh RK, Batra VS, and Balakrishnan M. Membrane bioreactor (MBR) for wastewater treatment Filtration performance evaluation of low cost polymeric and ceramic membranes. Sep. Purif. Technol. 2010 71 200-204. 

Fig. 12.2 (a) Schematic diagram for the filtration performance evaluation of the electrospun fibrous membranes, (b) Pressure drop of the PA-6 fibrous membranes and the HEPA filter as a function of face velocity for various fiber diameters, (c) Filtration efficiency of the PA-6 fibrous membranes and the HEPA filter as a function of particle size for various fiber diameters ((a) and (b) Reprinted with permission from [31]. 2008 Springer, (c) Reprinted with permission from [28]. 2006 Elsevier)... 

A continuous cross-flow filtration process has been utilized to investigate the effectiveness in the separation of nano sized (3-5 nm) iron-based catalyst particles from simulated Fischer-Tropsch (FT) catalyst/wax slurry in a pilot-scale slurry bubble column reactor (SBCR). A prototype stainless steel cross-flow filtration module (nominal pore opening of 0.1 pm) was used. A series of cross-flow filtration experiments were initiated to study the effect of mono-olefins and aliphatic alcohol on the filtration flux and membrane performance. 1-hexadecene and 1-dodecanol were doped into activated iron catalyst slurry (with Polywax 500 and 655 as simulated FT wax) to evaluate the effect of their presence on filtration performance. The 1-hexadecene concentrations were varied from 5 to 25 wt% and 1-dodecanol concentrations were varied from 6 to 17 wt% to simulate a range of FT reactor slurries reported in literature. The addition of 1-dodecanol was found to decrease the permeation rate, while the addition of 1-hexadecene was found to have an insignificant or no effect on the permeation rate. 

A blend of Polywax 500 and 655 (81.3 and 18.7 wt%, respectively) with a CO-activated ultrafine iron catalyst was used for the evaluation of catalyst/ wax slurry filtration performance of the filter module with and without an alcohol compound. All of the filtration tests were conducted with a TMP of... 

In evaluating the relative filtration rate of different carbons, it is important to consider that the filtration rate is a function of mechanical resistance that not only results from the shape and size of the carbon particles, but also depends on the filterability of the liquid. Some carbons are so effective for removing lyophilic colloids, gums, and resins that they give a better over-all filtration performance than does a carbon that has better mechanical structure, but lacks ability to remove colloidal substances. Consequently, comparisons of filtration of different carbons should be based on the solution to be... 

Xue, L., C.E. Thomas, and K.B. Roller Mainstream smoke gas phase filtration performance of adsorption materials evaluated with a puff-by-puff multiplex GC-MS method Beitr. Tabakforsch. Int. 20 (2003) 251-256. 

More recently, a composite aerosol filter media has been prepared by depositing polyvinyl alcohol (PVA) nanofibres with mean diameters of about lOOnm on nonwoven fabric substrates by using needleless electrospinning technique. The filtration performance of the composite filter was evaluated by measuring the filtration of sodium chloride nanoparticles (75 20nm). The results showed that the filtration efficiency of the composite filter media for nanoparticles was increased with the increase in thickness of the nanofibre mats, which was controlled by the deposition time of the electrospinning process. 

The potential of discussed approaches for high oi7-repellence of technical fabrics made of PET and its impact in the field of aerosol filtration was evaluated in a recent study by the authors [49]. The objective of this study was to assess the performance of technical fabrics as drainage media in compressed air filters. Drainage layers are designed to take up the oil from... 

ISO 16889 2008 Hydraidic fluid power — Filters — Multi-pass method for evaluating filtration performance of a filter element. ISO/NP 23369 HydrauUc fluid power filters — Multipass method of evaluating filtration performance of a filter element under cycHc flow conditions... 

Dilute stream shear testing was performed on the EP injection skid, where Injectivity would not be Impaired. The sheared polymer solution was sampled at the wellhead, and numerous tests were performed to detect the changes in polymer solution quality. Viscosity, screen factor, concentration of polymer, core plug injectivity and filtration performance were measured to evaluate the shear degraded polymer solution. 

Liao, K., Bhatia, S., 2006. Evaluation on filtration performance of woven geotextiles by falling head, pressure filtration, and hanging bag tests. In Proceedings 8th IGC, Yokohama, Japan. Millpress PubL, Rotterdam. 

Electrospun nanohbrous structure possess several attractive features, such as high porosity and interconnected open pore structure, submicron pore sizes, and a large surface area-to-volume ratio. These characteristics make them an ideal material candidate for removing sohd substances from air or hquid [6]. To demonstrate the filtration performance of electrospun nanohbre membrane, a thin coat of electrospun PAN nanohbres over a metal mesh has been shown to collect more than 95 % of PM2.5 (i.e. particulate matter in size of 2.5 pm) in a polluted city environment with 90 % transparency [323]. Filtration efficiency, which is closely associated with fibre fineness, is one of the most important concerns for the filter performance [6]. Molaeipour et al. [324] used ultrafine cellulose acetate nanofibres with different diameters to evaluate their filtration efficiencies for tar removal. It was found that... 

The multi-pass filter test is the normally used method for evaluating filtration performance. It consists of circulating a highly contaminated fluid through the test filter at constant flow rate and temperature. As the filter element picks up contaminant particles, the differential pressure drop across it increases. The test is terminated at a predetermined differential pressure across the filter, and three basic performance characteristics are evaluated separation efficiency (against particle size), contaminant holding capacity, and clean-assembly flow or pressure drop performance. 

Vacuum filters are usually simulated with a Buchner funnel test or filter leaf test (54). The measured parameters are cake weight, cake moisture, and filtration rate. Retention aids are usually evaluated using the Britt jar test, also called the Dynamic Drainage Jar, which simulates the shear conditions found on the paper machine and predicts performance (55). 

Comparative calculations of specific capacities of different filters or their specific filter areas should be made as part of the evaluation. Such calculations may be performed on the basis of experimental data obtained without using basic filtration equations. In designing a new filtration unit after equipment selection, calculations should be made to determine the specific capacity or specific filtration area. Basic filtration equations may be used for this purpose, with preliminary experimental constants evaluated. These constants contain information on the specific cake resistance and the resistance of the filter medium. 

In conclusion, the following experiments on filtration-washing-deliquoring should be performed to produce data (viscosity of liquids, effective solid concentration, specific cake resistance, cake compressibility, etc.) that are necessary to evaluate times of individual steps of filtration at an industrial scale, i.e. to obtain the proper basis for scale-up of filtration processes measure the filtrate volume versus time make marks on your vacuum flask and take down the time when the filtrate level reaches the mark => no more experiments are needed for preliminary evaluations of filtration properties of slurries initially fines pass the filter medium => recirculate them to the slurry,... 

Fig. 11. Evaluation of particle post-CMP performance for commercial oxide slurries with fumed and colloidal silica with and without point-of-use filtration. The filter size is 0.3 /im. The bottom denotes that the slurry used is from the bottom of the drum.

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