The collection performance of electret filters in the particle size range 10 nm-10 μm

Baumgartner, Hanspeter; Löffler, Friedrich

doi:10.1016/0021-8502(86)90126-6

Cited by 73 publications

(48 citation statements)

References 6 publications

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“…The bimodal penetration curves with a significant second mode predicted by model or the experimental ones only revealing a minor second mode have been found in the literature (Baumgartner and L€ offler, 1986;Kanaoka et al 1987;Tuinman, 1999;Ba»azy et al 2006).…”

Section: ¡1supporting

confidence: 54%

Carbon Nanotube Penetration Through Fiberglass and Electret Respirator Filter and Nuclepore Filter Media: Experiments and Models

Chen

Wang

Bahk

et al. 2014

Aerosol Science and Technology

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Three different respirator filter media (two electrets and one fiberglass) were challenged with monodisperse multi-walled carbon nanotubes (MWCNTs) of mobility diameters 20-500 nm at 5.3 and 10.6 cm s ¡1 face velocities. The penetration data were compared with that of sphere-like NaCl particles. The MWCNT penetrations were generally lower than those of NaCl at both face velocities in all three filters. However, the MWCNTs had a slightly higher penetration than the NaCl in the fiberglass filter at 10.6 cm s ¡1 face velocity when their mobility diameters were lower than 50 nm and the alignment effect was expected to occur. Results from the scanning electron microscopic (SEM) analysis supported the hypothesis of the alignment effect, which showed that the MWCNTs tend to be straighter or with higher aspectratios at the mobility sizes less than 100 nm, leading them more readily to align with the flow. Therefore, caution should be exercised when respirators are used against the MWCNTs with the mobility diameters less than 100 nm. The single fiber theory predicted the penetration of both particles in the fiberglass filters well for the particles with below 100 nm mobility diameters but discrepancies occurred beyond 100 nm. The theory still predicted the NaCl penetration through the electret filters well for the sizes below 100 nm but only predicted the MWCNT penetration well for »20-30 nm. The Nuclepore filter and the corresponding capillary tube model were adopted to study the mechanical deposition mechanisms of MWCNTs. The model was found to predict MWCNT penetration very well when the effective length of the MWCNT was taken into account.

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Section: ¡1supporting

confidence: 54%

Carbon Nanotube Penetration Through Fiberglass and Electret Respirator Filter and Nuclepore Filter Media: Experiments and Models

Chen

Wang

Bahk

et al. 2014

Aerosol Science and Technology

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“…Several papers relating to this subject that report experimental data have been published (Fissan et al, 1984;Baumgartner and Loffler, 1986;Lathrache et al, 1986;Lathrache and Fissan, 1987;Brown, 1989;Trottier and Brown, 1990). However, the lack of reported experimental parameters in these papers required for our theoretical calculations or the difference in charging conditions from our model (some dealing with the particles in charge equilibrium, some for charged particles-neutral filter or for neutral particles-charged filter), hinders comparison.…”

Section: Coulombic Repulsionmentioning

confidence: 98%

Deposition of Particles on a Single Cylinder by a Coulombic Force and Direct Interception

Colbeck

Zhang

1993

Aerosol Science and Technology

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The deposition efficiency of particles on a single cylinparticles and cylinder are charged with same and reder by a coulomhic force and direct interception is verse sign are considered, also with potential and vistheoretically investigated by combining the methods of cous flows. The results obtained are compared with Duchin-Deryaguin and Pich. The cases in which the existing theories and experiments.

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“…5 The aerosol capture mechanisms of these filters depend on a combination of the electrostatic mechanisms (dielectrophoretic and Coulombic), as well as the conventional mechanisms, including impaction, interception, diffusion, and gravitationally settling. Many studies [6][7][8][9] have examined the capture mechanisms of electret filters; some studies [10][11][12][13] have developed theoretical and semiempirical expressions for dielectrophoretic and Coulombic singlefiber efficiencies to describe the capture efficiency of electret filters with different charge configurations. Several researchers 6,12,14,15 have studied the performance of electret filters.…”

Section: Introductionmentioning

confidence: 99%

Electrostatic Enhancement of Collection Efficiency of the Fibrous Filter Pretreated with Ionic Surfactants

Yang

Lee

2005

Journal of the Air & Waste Management Association

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A study of the electrostatic enhancement of collection efficiency of filters pretreated with ionic surfactants has been carried out in controlled conditions with monodisperse aerosols. Cationic surfactant (dimethyl dioctadecylammonium bromide [DDAB]) and anionic surfactant (sodium oleate [SO]) were used to pretreat polypropylene fibrous filters as the positively and negatively charged filters, respectively. The effects of aerosol size, aerosol charge state, face velocity, aerosol type, and relative humidity (RH) were considered to elucidate their influence on the aerosol penetration. Results indicate that penetration through surfactant-pretreated filters was lower than that through untreated filters, and pretreatment of the filter with surfactant was observed not to affect the structure of the filter. The electrofieldmeter direct-measured the very clear electric field of filter when treating ionic surfactants. The results proved that pretreatment with surfactant caused filters to become charged. Comparing penetration through surfactant-pretreated filters with that through untreated filters with neutral aerosol, the penetration reduction factor of the surfactant-pretreated filters was in the range 1.3-2.2. Comparing aerosol penetration through the surfactant-pretreated filters with singly charged aerosol with that through untreated filters with uncharged aerosol indicates that the former decreases by a factor of 1.8 -48.8. The surface fiber charges of the DDAB-and SO-pretreated filters were calculated to be 2.02 ϫ 1 Ϫ10 C/m and Ϫ1.53 ϫ 10 Ϫ10 C/m. Moreover, the aerosol penetrations through the surfactant-pretreated filters increased with the face velocity. Surfactant-pretreated filters performed better against solid aerosol than against liquid aerosol. RH has no effect on aerosol penetration through the surfactant-pretreated filters. Regression equations for Coulombic and dielectrophoretic single-fiber efficiencies in terms of the dimensionless parameters could be fitted by the experimental measurements of surfactantpretreated filters in this work.

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The collection performance of electret filters in the particle size range 10 nm-10 μm

Cited by 73 publications

References 6 publications

Carbon Nanotube Penetration Through Fiberglass and Electret Respirator Filter and Nuclepore Filter Media: Experiments and Models

Carbon Nanotube Penetration Through Fiberglass and Electret Respirator Filter and Nuclepore Filter Media: Experiments and Models

Deposition of Particles on a Single Cylinder by a Coulombic Force and Direct Interception

Electrostatic Enhancement of Collection Efficiency of the Fibrous Filter Pretreated with Ionic Surfactants

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