Study of the effect of humidity, particle hygroscopicity and size on the mass loading capacity of HEPA filters
- India Inst. of Technology, Delhi (India)
The effect of humidity, particle hygroscopicity and size on the mass loading capacity of glass fiber HEPA filters has been studied. At humidifies above the deliquescent point, the pressure drop across the HEPA filter increased non-linearly with the areal loading density (mass collected/filtration area) of NaCl aerosol, thus significantly reducing the mass loading capacity of the filter compared to dry hygroscopic or non-hygroscopic particle mass loadings. The specific cake resistance, K2, has been computed for different test conditions and used as a measure of the mass loading capacity. K. was found to decrease with increasing humidity for the non-hygroscopic aluminum oxide particles and the 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 K2 for lognormally distributed aerosols (parameters obtained from impactor data) is derived. The resistance factor, R, calculated using this formula was compared to the theoretical R calculated using the Rudnick-Happel expression. For the non-hygroscopic 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.
- Research Organization:
- Westinghouse Savannah River Co., Aiken, SC (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC09-89SR18035
- OSTI ID:
- 10172571
- Report Number(s):
- WSRC-MS--92-114; CONF--921110--23; ON: DE92019679
- Country of Publication:
- United States
- Language:
- English
Similar Records
Study of the effect of humidity, particle hygroscopicity and size on the mass loading capacity of HEPA filters
Effect of humidity and particle hygroscopicity on the mass loading capacity of high efficiency particulate air (HEPA) filters
Effect of humidity on the filter pressure drop
Conference
·
Tue Dec 31 23:00:00 EST 1991
·
OSTI ID:7270999
Effect of humidity and particle hygroscopicity on the mass loading capacity of high efficiency particulate air (HEPA) filters
Journal Article
·
Thu Jul 01 00:00:00 EDT 1993
· Aerosol Science and Technology; (United States)
·
OSTI ID:5685673
Effect of humidity on the filter pressure drop
Technical Report
·
Tue Jan 31 23:00:00 EST 1995
·
OSTI ID:95649