Particle size for greatest penetration of HEPA filters - and their true efficiency
The particle size that most greatly penetrates a filter is a function of filter media construction, aerosol density, and air velocity. In this paper the published results of several experiments are compared with a modern filtration theory that predicts single-fiber efficiency and the particle size of maximum penetration. For high-efficiency particulate air (HEPA) filters used under design conditions this size is calculated to be 0.21 ..mu..m diam. This is in good agreement with the experimental data. The penetration at 0.21 ..mu..m is calculated to be seven times greater than at the 0.3 ..mu..m used for testing HEPA filters. Several mechanisms by which filters may have a lower efficiency in use than when tested are discussed.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 6241348
- Report Number(s):
- UCRL-53311; ON: DE83008439
- Resource Relation:
- Other Information: Portions are illegible in microfiche products. Original copy available until stock is exhausted
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AEROSOLS
FILTRATION
FILTERS
EFFICIENCY
RADIOACTIVE AEROSOLS
AIR POLLUTION
AIR POLLUTION CONTROL
COMPARATIVE EVALUATIONS
DENSITY
PARTICLE SIZE
REVIEWS
VELOCITY
COLLOIDS
CONTROL
DISPERSIONS
DOCUMENT TYPES
PHYSICAL PROPERTIES
POLLUTION
POLLUTION CONTROL
SEPARATION PROCESSES
SIZE
SOLS
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)
500300 - Environment
Atmospheric- Radioactive Materials Monitoring & Transport- (-1989)