Experimental and theoretical analysis of loading characteristics of electret filter media for charged particles--颗粒学报PARTICUOLOGY

Cai, Y., Cai, R., & Zhang, L. (2024). Experimental and theoretical analysis of loading characteristics of electret filter media for charged particles. Particuology, 93, 87-98. https://doi.org/10.1016/j.partic.2024.06.007

Experimental and theoretical analysis of loading characteristics of electret filter media for charged particles

Yiqi Cai^a, Rongrong Cai^a *, Lizhi Zhang^{a b}

a Key Laboratory of Enhanced Heat Transfer and Energy Conservation of Education Ministry, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, China
b State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou, 510640, China

10.1016/j.partic.2024.06.007

Volume 93, October 2024, Pages 87-98

Received 9 March 2024, Revised 21 May 2024, Accepted 12 June 2024, Available online 21 June 2024, Version of Record 26 June 2024.

E-mail: cerrcai@scut.edu.cn

Highlights

• Particle charge quantity was quantitatively determined by numerical simulation.

• Particle charge polarity had a negligible impact on loading performance of electret media.

• Electrostatic attenuation factor was negatively exponentially correlated with particle charge quantity.

• Electrostatic enhancement and electrostatic shielding effect jointly affected loading performance.

Abstract

The degradation of filtration performance in electret filter media during usage poses a significant challenge. Pre-charging of aerosols has been identified as an effective method to mitigate this issue. However, the effects of particle charging characteristics on the loading characteristics of electret filters still need a comprehensive understanding. In this study, a needle-cylinder corona charger was employed to pre-charge aerosols, and the particle charge state was determined by multiphysics simulation. The effects of particle charge polarity and charge quantity on the loading performance of the electret filter were quantitatively investigated. The results showed that the particle charge polarity had a negligible impact on the loading performance under the condition of the equivalent particle charge quantity. In addition, the charged particles effectively improved the efficiency degradation during the loading process of electret media, with higher charge quantities resulting in more pronounced improvements. The electrostatic attenuation factor showed a negative exponential correlation with the particle charge quantity. This was attributed to the uneven particle deposition on fiber surface due to the attraction of charged particles by the opposite charges on the electret fibers, which alleviated the effect of electrostatic shielding.

Graphical abstract

Keywords

Electret filter; Charged particles; Loading characteristic; Corona charging; Electrostatic screening

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