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Behnam Pourdeyhimi - One of the best experts on this subject based on the ideXlab platform.
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The Charging and Stability of Electret Filters
Fibrous Filter Media, 2017Co-Authors: Ali Kilic, Eunkyoung Shim, Stephen J. Russell, Behnam PourdeyhimiAbstract:Having a long history in Aerosol Filtration technologies, electret filters are one of the basic solutions to provide high particle capture efficiency at a low pressure drop and energy expense. However, their reliability is still an ongoing issue from the aspects of high efficiency and stability. In this chapter the theory behind electret mechanism, charging of the fibrous materials, their discharging and stability were reviewed in detail. Physics behind the widely used electret filter charging/polarization mechanisms were also discussed.
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Aerosol Filtration properties of nucleating agent containing electret filters
Polymer Engineering & Science, 2013Co-Authors: Ali Kilic, Behnam Pourdeyhimi, Eunkyoung Shim, Bong-yeol YeomAbstract:This study reports on the effects of nucleating agents on morphology, charging, and electrostatic Filtration performance of polypropylene meltblown webs. Two commercial nucleating agents, DMDBS (3:2, 4-bis(3,4-dimethyldibenzylidene) sorbitol) and NA11 (sodium 2,2′-methylene-bis(4,6-di-tertbutylphenyl)-phosphate) were compared. It is hypothesized that faster solidification brought about by the addition of the nucleating agents may be responsible for the slight increase in fiber diameter and concomitant reduction in web solidity. Samples were charged at room temperature as well as at elevated temperatures. Upon thermal charging, significant enhancement in the electrostatic potential and Filtration performance of the webs was observed. Particularly, the stability of electrostatic Filtration performance was found to be promising with the addition of these polarizable additives. Dielectric spectroscopy tests confirmed an increase in capacitance for samples containing nucleating agents. POLYM. ENG. SCI., 54:1533–1539, 2014. © 2013 Society of Plastics Engineers
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Aerosol Filtration properties of PA6/PE islands-in-the-sea bicomponent spunbond web fibrillated by high-pressure water jets
Journal of Materials Science, 2011Co-Authors: Bong-yeol Yeom, Behnam PourdeyhimiAbstract:The bicomponent spunbonding technology offers high productivity and provides great flexibility in the selection of polymer compositions and fiber configurations. This process was utilized to develop islands-in-the-sea (INS) fabrics consisting of 75% nylon-6 islands and 25% PE sea polymer. The number of islands was varied from 1 (sheath-core) to 108. These webs were hydroentangled at high pressure to cause fracture and fibrillation of the sea polymer and to “release” the islands to form hybrid micro and nanofiber structures. Physical properties as well as Aerosol Filtration characteristics of these webs were investigated to determine their feasibility for Aerosol Filtration. The submicron-sized dioctyl phthalate (DOP) particles were used as a challenging Aerosol at face velocities in range of 3.3–11.7 cm/s. The Filtration efficiency of the webs followed typical behavior for fibrous Filtration media in which the most penetration particle size was in range of 0.2–0.3 micron. Surprisingly, the 1 INS web exhibited a higher quality factor compared with other INS webs due to its lower solidity. Also, it was found that corona charging improved the Filtration efficiency of 1 INS web 4.3 times compared to discharged webs for 0.2 micron of DOP particles at the face velocity of 5.3 cm/s.
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Aerosol Filtration properties of pa6 pe islands in the sea bicomponent spunbond web fibrillated by high pressure water jets
Journal of Materials Science, 2011Co-Authors: Bong-yeol Yeom, Behnam PourdeyhimiAbstract:The bicomponent spunbonding technology offers high productivity and provides great flexibility in the selection of polymer compositions and fiber configurations. This process was utilized to develop islands-in-the-sea (INS) fabrics consisting of 75% nylon-6 islands and 25% PE sea polymer. The number of islands was varied from 1 (sheath-core) to 108. These webs were hydroentangled at high pressure to cause fracture and fibrillation of the sea polymer and to “release” the islands to form hybrid micro and nanofiber structures. Physical properties as well as Aerosol Filtration characteristics of these webs were investigated to determine their feasibility for Aerosol Filtration. The submicron-sized dioctyl phthalate (DOP) particles were used as a challenging Aerosol at face velocities in range of 3.3–11.7 cm/s. The Filtration efficiency of the webs followed typical behavior for fibrous Filtration media in which the most penetration particle size was in range of 0.2–0.3 micron. Surprisingly, the 1 INS web exhibited a higher quality factor compared with other INS webs due to its lower solidity. Also, it was found that corona charging improved the Filtration efficiency of 1 INS web 4.3 times compared to discharged webs for 0.2 micron of DOP particles at the face velocity of 5.3 cm/s.
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influence of fiber orientation distribution on performance of Aerosol Filtration media
Chemical Engineering Science, 2010Co-Authors: S Fotovati, Vahedi H Tafreshi, Behnam PourdeyhimiAbstract:Abstract This work is conducted to better our understanding of the influence of fibers’ in-plane and through-plane orientations on pressure drop and collection efficiency of fibrous media. The Stokes flow equations are numerically solved in virtual, 3-D, fibrous geometries with varying in-plane and/or through-plane orientations. Pressure drop and Aerosol collection efficiency characteristics of such media are calculated and compared with available studies from the literature. Our results indicate that pressure drop and submicron particle capture efficiency of common fibrous filters with a fiber diameter of about 10 μm are independent of the in-plane orientation of the fibers, but decrease with increasing the fibers’ through-plane orientation. More interestingly, it was found that filters with higher through-plane fiber orientations have a higher figure of merit if challenged with nanoparticles. The figure of merit of these media, however, decreases as the particle size increases, reversing the effect of fibers’ through-plane orientation. It was also shown that when the diameter of the particles is comparable to that of the fibers, collection efficiency increases with decreasing the fibers’ in-plane orientation, while the pressure drop remains almost unchanged. This indicates that decreasing the fibers’ in-plane orientation increased the figure of merit of media made of nanofibers.
Bong-yeol Yeom - One of the best experts on this subject based on the ideXlab platform.
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Aerosol Filtration properties of nucleating agent containing electret filters
Polymer Engineering & Science, 2013Co-Authors: Ali Kilic, Behnam Pourdeyhimi, Eunkyoung Shim, Bong-yeol YeomAbstract:This study reports on the effects of nucleating agents on morphology, charging, and electrostatic Filtration performance of polypropylene meltblown webs. Two commercial nucleating agents, DMDBS (3:2, 4-bis(3,4-dimethyldibenzylidene) sorbitol) and NA11 (sodium 2,2′-methylene-bis(4,6-di-tertbutylphenyl)-phosphate) were compared. It is hypothesized that faster solidification brought about by the addition of the nucleating agents may be responsible for the slight increase in fiber diameter and concomitant reduction in web solidity. Samples were charged at room temperature as well as at elevated temperatures. Upon thermal charging, significant enhancement in the electrostatic potential and Filtration performance of the webs was observed. Particularly, the stability of electrostatic Filtration performance was found to be promising with the addition of these polarizable additives. Dielectric spectroscopy tests confirmed an increase in capacitance for samples containing nucleating agents. POLYM. ENG. SCI., 54:1533–1539, 2014. © 2013 Society of Plastics Engineers
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Aerosol Filtration properties of PA6/PE islands-in-the-sea bicomponent spunbond web fibrillated by high-pressure water jets
Journal of Materials Science, 2011Co-Authors: Bong-yeol Yeom, Behnam PourdeyhimiAbstract:The bicomponent spunbonding technology offers high productivity and provides great flexibility in the selection of polymer compositions and fiber configurations. This process was utilized to develop islands-in-the-sea (INS) fabrics consisting of 75% nylon-6 islands and 25% PE sea polymer. The number of islands was varied from 1 (sheath-core) to 108. These webs were hydroentangled at high pressure to cause fracture and fibrillation of the sea polymer and to “release” the islands to form hybrid micro and nanofiber structures. Physical properties as well as Aerosol Filtration characteristics of these webs were investigated to determine their feasibility for Aerosol Filtration. The submicron-sized dioctyl phthalate (DOP) particles were used as a challenging Aerosol at face velocities in range of 3.3–11.7 cm/s. The Filtration efficiency of the webs followed typical behavior for fibrous Filtration media in which the most penetration particle size was in range of 0.2–0.3 micron. Surprisingly, the 1 INS web exhibited a higher quality factor compared with other INS webs due to its lower solidity. Also, it was found that corona charging improved the Filtration efficiency of 1 INS web 4.3 times compared to discharged webs for 0.2 micron of DOP particles at the face velocity of 5.3 cm/s.
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Aerosol Filtration properties of pa6 pe islands in the sea bicomponent spunbond web fibrillated by high pressure water jets
Journal of Materials Science, 2011Co-Authors: Bong-yeol Yeom, Behnam PourdeyhimiAbstract:The bicomponent spunbonding technology offers high productivity and provides great flexibility in the selection of polymer compositions and fiber configurations. This process was utilized to develop islands-in-the-sea (INS) fabrics consisting of 75% nylon-6 islands and 25% PE sea polymer. The number of islands was varied from 1 (sheath-core) to 108. These webs were hydroentangled at high pressure to cause fracture and fibrillation of the sea polymer and to “release” the islands to form hybrid micro and nanofiber structures. Physical properties as well as Aerosol Filtration characteristics of these webs were investigated to determine their feasibility for Aerosol Filtration. The submicron-sized dioctyl phthalate (DOP) particles were used as a challenging Aerosol at face velocities in range of 3.3–11.7 cm/s. The Filtration efficiency of the webs followed typical behavior for fibrous Filtration media in which the most penetration particle size was in range of 0.2–0.3 micron. Surprisingly, the 1 INS web exhibited a higher quality factor compared with other INS webs due to its lower solidity. Also, it was found that corona charging improved the Filtration efficiency of 1 INS web 4.3 times compared to discharged webs for 0.2 micron of DOP particles at the face velocity of 5.3 cm/s.
Weihong Xing - One of the best experts on this subject based on the ideXlab platform.
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Amphiphobic PFTMS@nano-SiO2/ePTFE Membrane for Oil Aerosol Removal
Industrial & Engineering Chemistry Research, 2018Co-Authors: Fang Jian, Ze Xian Low, Shasha Feng, Zhaoxiang Zhong, Weihong XingAbstract:Synthetic expanded polytetrafluoroethylene (ePTFE) membrane has a wide range of applications, including Aerosol and dust removal, and exhibits high dust-removing efficiency, high air permeability, and cost-effectiveness. However, the intrinsic oleophilic surface of ePTFE limits its application in the oil-bearing gas–solid separation process. Herein, we report a surface modification method to prepare amphiphobic ePTFE membranes via coating of a layer of 1H,1H,2H,2H-perfluorooctyltrimethoxysilane (PFTMS) – modified nano-SiO2 onto the surface of ePTFE fibers. The oil contact angle of the modified ePTFE membranes was increased from 0 to 123°, while retaining the initial water contact angle of 142°. The amphiphobic membrane shows excellent oil Aerosol Filtration efficiency with a comparative low pressure drop and high oil rejection rate of 99.5%. Remarkably, the membrane can be reused after simple rinsing with water. The oil Aerosol Filtration efficiency of membrane remained as high as 98.5% after five cycles ...
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Amphiphobic PFTMS@nano-SiO2/ePTFE Membrane for Oil Aerosol Removal
2018Co-Authors: Jian Fang, Ze Xian Low, Shasha Feng, Zhaoxiang Zhong, Weihong XingAbstract:Synthetic expanded polytetrafluoroethylene (ePTFE) membrane has a wide range of applications, including Aerosol and dust removal, and exhibits high dust-removing efficiency, high air permeability, and cost-effectiveness. However, the intrinsic oleophilic surface of ePTFE limits its application in the oil-bearing gas–solid separation process. Herein, we report a surface modification method to prepare amphiphobic ePTFE membranes via coating of a layer of 1H,1H,2H,2H-perfluorooctyltrimethoxysilane (PFTMS) – modified nano-SiO2 onto the surface of ePTFE fibers. The oil contact angle of the modified ePTFE membranes was increased from 0 to 123°, while retaining the initial water contact angle of 142°. The amphiphobic membrane shows excellent oil Aerosol Filtration efficiency with a comparative low pressure drop and high oil rejection rate of 99.5%. Remarkably, the membrane can be reused after simple rinsing with water. The oil Aerosol Filtration efficiency of membrane remained as high as 98.5% after five cycles of Filtration and cleaning
L.e. Sparks - One of the best experts on this subject based on the ideXlab platform.
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Aerosol Filtration efficiency of ventilation air cleaners. Report for January 1992-December 1994
1995Co-Authors: James Hanley, David S. Ensor, L.e. SparksAbstract:The paper discusses a test method for measuring the fractional Aerosol Filtration efficiency of air cleaners. The method provides a reliable and accurate way to measure air cleaner fractional efficiencies over the particle diameter size range of 0.01 to 10 micrometers. The need for a fractional efficiency test comes from several sources: (1) the growing concern with indoor air quality (IAQ); (2) that Filtration efficiency is often highly particle-size dependent for particles < 10 micrometers in diameter; (3) limitations of the current American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) efficiency test which, by design, cannot differentiate between particle sizes; and (4) that respirable particles are generally classified as those < 10 micrometers in diameter.
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Aerosol Filtration efficiency of ventilation air cleaners. Report for January 1992-December 1994
1995Co-Authors: James Hanley, David S. Ensor, L.e. SparksAbstract:The paper discusses a test method for measuring the fractional Aerosol Filtration efficiency of air cleaners. The method provides a reliable and accurate way to measure air cleaner fractional efficiencies over the particle diameter size range of 0.01 to 10 micrometers. The need for a fractional efficiency test comes from several sources: (1) the growing concern with indoor air quality (IAQ); (2) that Filtration efficiency is often highly particle-size dependent for particles < 10 micrometers in diameter; (3) limitations of the current American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) efficiency test which, by design, cannot differentiate between particle sizes; and (4) that respirable particles are generally classified as those < 10 micrometers in diameter.
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fractional Aerosol Filtration efficiency of in duct ventilation air cleaners
Indoor Air, 1994Co-Authors: James Hanley, D. D. Smith, David S. Ensor, L.e. SparksAbstract:The Filtration efficiency of ventilation air cleaners is highly particle-size dependent over the 0.01 to 3 μm diameter size range. Current standardized test methods, which determine only overall efficiencies for ambient Aerosol or other test Aerosols, provide data of limited utility. Because particles in this range are respirable and can remain airborne for prolonged time periods, measurement of air cleaner fractional efficiency is required for application to indoor air quality issues. The objectives of this work have been to 1) develop a test apparatus and procedure to quantify the fractional Filtration efficiency of air cleaners over the 0.01 to 3 μm diameter size range and 2) quantify the fractional efficiency of several induct air cleaners typical of those used in residential and office ventilation systems. Results show that efficiency is highly dependent on particle size, flow rate, and dust load present on the air cleaner. A minimum in efficiency was often observed in the 0.1 to 0.5 μm diameter size range. The presence of a dust load frequently increased an air cleaner's efficiency; however, some air cleaners showed little change or a decrease in efficiency with dust loading. The common furnace filter had fractional efficiency values of less than 10% over much of the measurement size range.
Fang Jian - One of the best experts on this subject based on the ideXlab platform.
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Amphiphobic PFTMS@nano-SiO2/ePTFE Membrane for Oil Aerosol Removal
Industrial & Engineering Chemistry Research, 2018Co-Authors: Fang Jian, Ze Xian Low, Shasha Feng, Zhaoxiang Zhong, Weihong XingAbstract:Synthetic expanded polytetrafluoroethylene (ePTFE) membrane has a wide range of applications, including Aerosol and dust removal, and exhibits high dust-removing efficiency, high air permeability, and cost-effectiveness. However, the intrinsic oleophilic surface of ePTFE limits its application in the oil-bearing gas–solid separation process. Herein, we report a surface modification method to prepare amphiphobic ePTFE membranes via coating of a layer of 1H,1H,2H,2H-perfluorooctyltrimethoxysilane (PFTMS) – modified nano-SiO2 onto the surface of ePTFE fibers. The oil contact angle of the modified ePTFE membranes was increased from 0 to 123°, while retaining the initial water contact angle of 142°. The amphiphobic membrane shows excellent oil Aerosol Filtration efficiency with a comparative low pressure drop and high oil rejection rate of 99.5%. Remarkably, the membrane can be reused after simple rinsing with water. The oil Aerosol Filtration efficiency of membrane remained as high as 98.5% after five cycles ...
