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

• Published in: Aerosol science and technology Vol. 42; no. 2; pp. 123 - 133
• Main Authors: PODGORSKI, Albert, BACAZY, Anna
• Format: Journal Article
• Language: English
• Published: London Taylor & Francis Group 01.01.2008; Taylor & Francis; Taylor & Francis Ltd
• Subjects: Aerosols; Brownian motion; Chemistry; Colloidal state and disperse state; Electronics; Exact sciences and technology; Fibers; General and physical chemistry; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Studies; Dynamics; Efficiency; Filter; Neutral particle; Aerosols; Deposition; Submicron particle
• DOI: 10.1080/02786820701809052
• ISSN: 0278-6826

Brownian dynamics (BD) method was employed to calculate the single fiber deposition efficiencies of electrically neutral, submicron aerosol particles in bipolarly charged and non-charged fibrous filters. It was found that a considerable increase in the deposition efficiency can be achieved by increasing the fiber charge density and that it is accompanied by a noticeable shift of the most penetrating particles size towards smaller particles. The results of the BD simulations obtained for various fiber charge densities and various particle diameters allowed us to derive new formulae relating a gain in the deposition efficiency due to action of the electrostatic force to the dimensionless polarization parameter, N σ 0 . These equations are applicable in much wider range of N σ 0 than other correlations available in the literature. A simple approximate rule for recalculating the form of the proposed formulae for another filter packing density was also presented. Theoretically predicted values of the deposition efficiency in bipolar electret filters were compared with our own experimental data as well as with the data available in the literature and a satisfactory agreement, better than in the case of other existing correlations, was obtained.