• Title/Summary/Keyword: Cunningham slip correction factor

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Approximation of most penetrating particle size for fibrous filters considering Cunningham slip correction factor

  • Jung, Chang Hoon;Yoon, Young Jun;Um, Junshik;Lee, Seoung Soo;Lee, Ji Yi;Chiao, Sen;Kim, Yong Pyo
    • Environmental Engineering Research
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    • v.25 no.3
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    • pp.439-445
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    • 2020
  • In the estimation of the aerosol single fiber efficiency using fibrous filters, there is a size range, where the particles penetrate most effectively through the fibrous collectors, and corresponding minimum single fiber efficiency. For small particles in which the diffusion mechanism is dominant, the Cunningham slip correction factor (Cc) affects the single fiber efficiency and the most penetrating particle size (MPPS). Therefore, for accurate estimation, Cc is essential to be considered. However, many previous studies have neglected this factor because of its complexity and the associated difficulty in deriving the appropriate parameterization particularly for the MPPS. In this study, the expression for the MPPS, and the corresponding expression for the minimum single fiber efficiency are analytically derived, and the effects of Cc are determined. In order to accommodate the slip factor for all particle-size ranges, Cc is simplified and modified. Overall, the obtained analytical expression for the MPPS is in a good agreement with the exact solution.

Collection Efficiency of Electrostatic Precipitator using Moment Method (모멘트 방법을 이용한 전기집진기의 집진 효율)

  • 정창훈;이규원
    • Journal of Korean Society for Atmospheric Environment
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    • v.18 no.5
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    • pp.345-353
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    • 2002
  • A study of polydispersed aerosol dynamics by Electrostatic Precipitator (ESP) was carried out. The log-normal particle size distribution was assumed and moment method was considered. In order to apply moment method in Deutsch-Anderson equation, Cunningham slip correction factor and Cochet's charge equation were simplified for certain range of particle size. The three parameters, which explain the particle size distribution, such as total number concentration, geometric mean diameter, and geometric standard deviation were considered to derive the analytic solution. The obtained solution was compared with available numerical results (Bai et al., 1995). The comparison of the numerical and analytic results showed a good agreement.