Initial Collection Performance of Resin Wool Filters and Estimation of Charge Density

Abstract

A new type of resin wool filter (RWF) that persists the load with oil droplets was developed by Kimura and colleagues. In the present work, the initial collection performances of RWF (A and C) are measured for various particle sizes ( −4 C/m 2 , which is much higher than those of conventional electret filter media. Therefore, RWF studied in the present work is suitable for the application to respirators as well as room air cleaners.

Novel Formulae for Deposition Efficiency of Electrically Neutral, Submicron Aerosol Particles in Bipolarly Charged Fibrous Filters Derived Using Brownian Dynamics Approach

“…The same formula was also quoted by Kim et al (2005), Lee et al (2002), and Otani et al (1993). However, Equation (29) is inconsistent with the original Brown's Equation (28) obtained for α = 0.05.…”

“…The simulations for bipolarly charged fibers of rectangular cross-section were done, e.g., by Cao et al (2004) and Cheung et al (2005), while the deposition on a cylindrical fiber with a line dipole charge distribution was investigated theoretically, e.g., by Brown (1981). The experimental data of filtration efficiency of neutral aerosol particles in electret filters were reported, e.g., by Lee et al (2002), Kim et al (2005), and Ba lazy et al (2006). In this work for the first time the Brownian dynamics method was used to evaluate the deposition efficiency of neutral, submicron aerosol particles onto cylindrical, bipolarly charged fibers.…”

“…As it was explained in the Appendix, the numerical constant is incorrect-instead of 0.54 it should be 0.41. For values of N σ 0 smaller than one, Otani et al (1993) proposed the following expressions [see also Kim et al (2005); Lee et al (2002)]: Experimental data of the single fiber deposition efficiency due to the polarization force as a function of the polarization parameter, E el (N σ 0 ), were reported for various electrically charged filters by Lee et al (2002) and by Kim et al (2005). Lee et al (2002) Comparing predictions of our new correlations it may be stated that Equation (26) seems to agree better with Kim's data, while for the Lee's data a better agreement is observed for Equation (27).…”

Intermediate Air Filters for General Ventilation Applications: An Experimental Evaluation of Various Filtration Efficiency Expressions

“…This is most likely connected to the charge state of the test aerosols used. All four studied test aerosols were either uncharged or charged to a little extent only, which means that the dominating electrostatic force is the induced force (Romay et al 1998;Kim et al 2005) which substantially decreases with air velocity (Kousaka et al 1989;Mostofi et al 2010) and increases with particle size (Lee and Liu 1980;Hinds 1999). Thus, in the case of charged synthetic filters, the influence from air velocity was mainly observed at particle sizes where filtration was strongly depending on induced electrostatic forces.…”

Removal of PM2.5 entering through the ventilation duct in an automobile using a carbon fiber ionizer-assisted cabin air filter

“…Kim, Otani, Noto, Namiki, and Kimura (2005) studied the initial collection performance of uncharged and single-charged particles using resin wool electret filters. Fjeld and Owens (1988) and Kanaoka, Emi, Otani, and Iiyama (1987) investigated the effect of particle charges on penetration.…”