Degradation Processes in Corona-Charged Electret Filter-Media with Exposure to Ethyl Benzene

2007 ◽  
Vol 2 (4) ◽  
pp. 155892500700200 ◽  
Author(s):  
J. Jasper Warren ◽  
Anushree Mohan ◽  
Juan Hinestroza ◽  
Roger Barker
Keyword(s):  
Direct Contact ◽  
Polypropylene Fiber ◽  
Filtration Efficiency ◽  
Benzene Vapor ◽  
Ethyl Benzene ◽  
Filter Media ◽  
Fiber Mats ◽  
Filtration Performance ◽  
Custom Made ◽  
Electret Filter

The degradation of filtration performance for corona-charged electret filter media exposed to ethyl benzene was assessed. Nonwoven corona-charged polypropylene fiber mats were exposed to ethyl-benzene using a custom made apparatus. Evaluated scenarios included ethyl-benzene vapor and liquid exposures. The filtration performance was evaluated using DOP as a test aerosol to measure filtration performance. It was observed that significant filtration degradation occurred only when liquid ethyl benzene came into direct contact with the filter media. No significant changes in the pressure drop or filtration efficiency was observed for any of the exposure scenarios in which the fibers were only exposed to ethyl benzene in the vapor phase.

Liquid-mediated particle capture by nonwoven filter media for automotive engine intake air filtration

2021 ◽  
pp. 152808372110610
Author(s):  
Shivendra Yadav ◽  
Dipayan Das
Keyword(s):  
Pressure Drop ◽  
Polypropylene Fiber ◽  
Nonwoven Fabric ◽  
Filtration Efficiency ◽  
Engine Oil ◽  
Air Filtration ◽  
Dust Deposition ◽  
Filter Media ◽  
Air Filter ◽  
Automotive Engine

This article reports on development, characterization, and performance of liquid-treated nonwoven air filter media for automotive engine intake application. A polypropylene fiber-based needle-punched nonwoven fabric was prepared for treatment with four viscous liquids (glycerol, SAE 20W/50 engine oil, PEG 400, and deionized water) by liquid spraying technique. The filtration performance was evaluated in terms of initial and final gravimetric filtration efficiencies, fractional filtration efficiency, evolution of pressure drop, and dust holding capacity. The liquid-treated filter media registered higher gravimetric as well as fractional filtration efficiency and higher dust holding capacity as compared to the untreated ones. The initial and final gravimetric filtration efficiencies were found to be directly related to liquid add-on via a power law relationship. The liquid-treated filter media also exhibited higher fractional filtration efficiency than their untreated counterparts for all sizes of tested particles. Interestingly, the increase of fractional efficiency was more for smaller particles as compared to larger ones. This was explained quantitatively through single fiber efficiency due to adhesion. The viscosity of liquid was found to be a very crucial parameter as the dust deposition morphology was contingent to the flow of liquid onto the filter media. The stickiest liquid yielded highest filtration efficiencies, displayed slowest rise of pressure drop, and exhibited highest dust holding capacity.

scholarly journals Study on the Filtration Performance of the Baghouse Filters for Ultra-Low Emission as a Function of Filter Pore Size and Fiber Diameter

2019 ◽  
Vol 16 (2) ◽  
pp. 247 ◽  
Author(s):  
Xingcheng Liu ◽  
Henggen Shen ◽  
Xueli Nie
Keyword(s):  
Pore Size ◽  
Fiber Diameter ◽  
Filtration Efficiency ◽  
Filter Media ◽  
Filtration Resistance ◽  
Filtration Performance ◽  
Fabric Structure ◽  
Dynamic Filtration ◽  
Depth Filtration ◽  
Surface Filtration

The main objective of this study was to determine the effect of filter pore size and fiber diameter on the performance of the baghouse filters for ultra-low emission. In this study, three kinds of conventional polyester filter (depth filtration media) and two kinds of polytetrafluoroethylene membrane-coated polyester filter (surface filtration media), having various filter pore sizes and fiber diameters, were tested to determine the performance of static and dynamic filtration. In order to determine the static filtration performance, the filtration resistance and the filtration efficiency of the clean filter media were measured by the arrestance method. The dynamic filtration performance experiments were conducted to determine the dynamic resistances, dust depositions, and dynamic filtration efficiencies of the dust-containing filter media under the condition of dust airflow filtration through a pulse-cleaning cycle. In the dynamic filtration performance experiments, the size of 50% test dust was less than 2.5 μm, and the mass mean aerodynamic diameter of the dust was 1.5 μm. The filtration velocity was 2 m∙min−1, and the dust concentration was 18.4 g∙m−3. The static filtration performance experiments showed that the filter pore size greatly affected the filtration resistance and the filtration efficiency of the fabric structure of the surface filtration media. In the depth filtration media, the filtration efficiency and the filtration resistance of the fabric structure were improved when the filter pore size and the fiber diameter were smaller in magnitude. For all the five filter media, smaller the pore size of the filter media, greater was the filtration precision (for fine particles, such as PM2.5) of the fabric structure. In the dynamic filtration performance experiments, the filter pore size and the fiber diameter of the depth filtration media affected the dynamic filtration resistance and the dynamic filtration efficiency of the depth filtration media by affecting the deposition rate of dust in the depth filtration media; however, the filter pore size of the surface filtration media affected the blocking rate of dust in the membrane micropores, thus influencing the dynamic filtration resistance and the dynamic filtration efficiency of the surface filtration media.

Filtration efficiency and loading characteristics of PM2.5 through commercial electret filter media

2018 ◽  
Vol 195 ◽  
pp. 101-109 ◽  
Author(s):  
Min Tang ◽  
Drew Thompson ◽  
De-Qiang Chang ◽  
Sheng-Chieh Chen ◽  
David Y.H. Pui
Keyword(s):  
Filtration Efficiency ◽  
Filter Media ◽  
Electret Filter

Coalescence filtration performance of blended microglass and electrospun polypropylene fiber filter media

2014 ◽  
Vol 124 ◽  
pp. 1-8 ◽  
Author(s):  
Prashant S. Kulkarni ◽  
Shagufta U. Patel ◽  
Sarfaraz U. Patel ◽  
George G. Chase
Keyword(s):  
Polypropylene Fiber ◽  
Filter Media ◽  
Filtration Performance ◽  
Fiber Filter

scholarly journals Evaluation of the Filtration Performance of Biocide Loaded Filter Media

1999 ◽  
Vol os-8 (2) ◽  
pp. 1558925099OS-80
Author(s):  
Wayne T. Davis ◽  
B. Alan Phillips ◽  
Maureen Dever ◽  
Thomas C. Montie ◽  
Kimberly Kelly-Wintenberg ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Indoor Air ◽  
Opportunistic Pathogen ◽  
Filtration Efficiency ◽  
Post Treatment ◽  
Test Stand ◽  
Particle Removal ◽  
Filter Media ◽  
Small Disk ◽  
Filtration Performance

This paper presents the results of a study designed to evaluate the filtration performance of nonwoven filtration media which have been loaded with a variety of biocides for use as potential indoor air filters. A test stand was constructed based on a modification of the ASTM 1215 Standard to provide testing of the bacterial removal efficiency of the filtration media. Biocide-loaded filtration media were first tested on an ASTM 1215 test stand using standard monodispersed latex spheres to determine the particle removal efficiency as a function of particle sizes in the 0.5 to 2.0 micrometer sizes. A multichannel optical particle counter was used to assess the efficiency. Additional samples of the same media were then tested in the modified ASTM 1215 test stand, referred to as the Biocontaminant Indoor Air Quality Test Stand (BIAQTS) by atomizing bacteria (Gram positive and Gram negative) and fungi into the test stand. Initial bacterial testing was conducted using single-stage microbial samplers to determine the efficiency of filters for removing Escherichia coli (E. coli) bacteria and other bacteria. In addition to testing the filtration efficiency, additional tests were conducted on samples of the filter by placing small disk samples of the unexposed biocide-loaded filters and a non-loaded control filter onto microorganism-loaded agar in petri dishes. Microorganisms studied included four bacteria, a fungus, and an opportunistic pathogen. The samples were then incubated and quantitative analyses were conducted to determine the zone of inhibited growth of the microorganisms around the disks due to the biocide treatments which were applied to the filters. The results are presented for two of a series of biocide-loaded nonwoven filters which were prepared using two different techniques for loading the biocides: 1) nonwoven filters which were prepared by mixing the biocide with the polypropylene polymer prior to meltblowing the polymer into a filter - referred to as impregnated biocide, and 2) spray application of the biocides as a finish onto the filter media–referred to as post treatment. The effects of impregnated versus post treatment applications on filtration efficiency and on the inhibition of bacterial growth on the filters are presented.

Production and Characterization of Nanoporous Polymer Membranes Produced by an Electrospraying Process

2000 ◽  
Author(s):  
Phillip Gibson ◽  
Heidi Schreuder-Gibson
Keyword(s):  
Transport Properties ◽  
Membrane Structure ◽  
Protective Clothing ◽  
Theoretical Calculations ◽  
Electrospun Fiber ◽  
Air Flow ◽  
Filtration Efficiency ◽  
Thin Layers ◽  
Direct Result ◽  
Fiber Mats

Abstract Electrospinning is a process by which high voltages are used to produce an interconnected membrane-like web of small fibers (10 to 500 nanometers in diameter). This novel fiber spinning technique provides the capacity to lace together a variety of types of polymers, fibers, and particles to produce ultrathin layers which are useful for chemical protective clothing. Of particular interest are electrospun membranes composed of elastomeric fibers, which are under development for several protective clothing applications. The various factors influencing electrospun nonwoven fibrous membrane structure and transport properties are discussed. Performance measurements on experimental electrospun fiber mats compared favorably with transport properties of textiles and membranes currently used in protective clothing systems. It was found that electrospun layers presented minimal impedance to moisture vapor diffusion required for evaporative cooling. There may be special considerations in the application of elastomeric membranes for protective clothing. Effects of membrane distortion upon transport behavior of the structure might be significant. Preliminary measurements have found that changes in elastomeric membrane structure under different states of biaxial strain were reflected in measurements of air flow through the membrane. Changes in membrane structure were also evident in environmental scanning electron microscope images of the pore/fiber rearrangement as the membrane was stretched. Experimental measurements and theoretical calculations show electrospun fiber mats to be extremely efficient at trapping airborne particles. The high filtration efficiency is a direct result of the submicron-size fibers generated by the electrospinning process. Electrospun nanofiber coatings were applied directly to an open cell polyurethane foam. The air flow resistance and aerosol filtration properties correlated with the electrospun coating add-on weight. Particle penetration through the foam layer, which is normally very high, was eliminated by extremely thin layers of electrospun nanofibers sprayed on to the surface of the foam. Electrospun fiber coatings produce an exceptionally lightweight multifunctional membrane for protective clothing applications which exhibits high breathability, elasticity, and filtration efficiency.

Preparation and filtration performance of the circular weft-knitted seamless weft-insertion fabric materials

2019 ◽  
pp. 152808371985532 ◽  
Author(s):  
Fei Tian ◽  
Gaoming Jiang ◽  
Zhe Gao
Keyword(s):  
Pore Size ◽  
Production Efficiency ◽  
Filtration Efficiency ◽  
High Porosity ◽  
Filtration Performance ◽  
Air Particulate ◽  
Forming Technology ◽  
New Type ◽  
High Production ◽  
Fabric Materials

Air particulate matter pollution has become a severe environment concern calling for filtration materials with great filtration performance. As the development of seamless forming technology, knitted filtration materials gradually show great potential. This study aimed to develop a novel kind of knitted seamless structure for filtration materials of filter bags with high production efficiency and excellent filtration performance. A new type of the circular weft-knitted seamless weft-insertion fabric (CKSW) filtration materials were developed on the modified circular knitting machine. This CKSW filtration materials consisting of the ground yarns, connection yarns and weft-insertion yarns, polyester full drawn yarns, and polyester draw texturing yarns with different yarn configurations were employed to realize series of CKSW samples. The polytetrafluoroethylene filaments with tourmaline particles were used to verify whether the static electric material produced an adsorption filtration effect on the CKSW filtration materials or not. After pretreatment, the filtration performance of the CKSW filtration materials was evaluated by analyzing its pore size, porosity, and filtration efficiency. Ultimately, the CKSW filtration materials with ground yarns and weft insertion yarns of draw texturing yarn and the connection yarns of full drawn yarn exhibited the most excellent filtration performance. The CKSW filtration materials show a high porosity of 87.14%, the pore size of 67.55 µm, and good filtration efficiency of 91.57% with the particles size of ≥ 5.0 µm. The successful fabrication of such knitted filtration materials may provide ideas for the development of filtration materials with new architecture mainly used as filter bags for baghouse.

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