Effect of humidity and particle hygroscopicity on the mass loading capacity of high efficiency particulate air (HEPA) filters

Journal Article · Thu Jul 01 04:00:00 EDT 1993 · Aerosol Science and Technology; (United States)

DOI:https://doi.org/10.1080/02786829308959624· OSTI ID:5685673

Gupta, A; Biswas, P ^[1]; Monson, P R ^[2]; Novick, V J ^[3]

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1. Univ. of Cincinnati, OH (United States)
2. Westinghouse Savannah River Company, Aiken, SC (United States)
3. Argonne National Lab., IL (United States)

The effect of humidity, particle hygroscopicity, and size on the mass loading capacity of glass fiber high efficiency particulate air filters was studied. Above the deliquescent point, the pressure drop across the filter increased nonlinearly with areal loading density (mass collected/filtration area) of a NaCl aerosol, thus significantly reducing the mass loading capacity of the filter compared to dry hygroscopic or nonhygroscopic particle mass loadings. The specific cake resistance K[sub 2] was computed for different test conditions and used as a measure of the mass loading capacity. K[sub 2] was found to decrease with increasing humidity for nonhygroscopic aluminum oxide particles and for hygroscopic NaCl particles (at humidities below the deliquescent point). It is postulated that an increase in humidity leads to the formation of a more open particulate cake which lowers the pressure drop for a given mass loading. A formula for predicting K[sub 2] for lognormally distributed aerosols (parameters obtained from impactor data) was derived. The resistance factor, R, calculated using this formula was compared to the theoretical R calculated using the Rudnick-Happel expression. For the nonhygroscopic aluminum oxide, the agreement was good but for the hygroscopic sodium chloride, due to large variation in the cake porosity estimates, the agreement was poor. 17 refs., 6 figs., 3 tabs.

• DOE Contract Number: W-31109-ENG-38; AC09-89SR18035
• OSTI ID: 5685673
• Journal Information: Aerosol Science and Technology; (United States), Journal Name: Aerosol Science and Technology; (United States) Vol. 19:1; ISSN 0278-6826; ISSN ASTYDQ
• Country of Publication: United States
• Language: English

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ACCIDENTS
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