Fire protection countermeasures for containment ventilation systems
The goal of this project is to find countermeasures to protect HEPA filters in exit ventilation ducts from the heat and smoke generated by fire. Several methods for partially mitigating the smoke exposure to the HEPA filters were identified through testing and analysis. These independently involve controlling the fuel, controlling the fire, and intercepting the smoke aerosol prior to its sorption on the HEPA filter. Exit duct treatment of aerosols is not unusual in industrial applications and involves the use of scrubbers, prefilters, and inertial impaction, depending on the size, distribution, and concentration of the subject aerosol. However, when these unmodified techniques were applied to smoke aerosols from fires on materials, common to experimental laboratories of LLNL, it was found they offered minimal protection to the HEPA filters. Ultimately, a continuous, movable, high-efficiency prefilter using modified commercial equipment was designed. This technique is capable of protecting HEPA filters over the total duration of the test fires. The reason for success involved the modificaton of the prefiltration media. Commercially available filter media has a particle sorption efficiency that is inversely proportional to media strength. To achieve properties of both efficiency and strength, we laminated rolling filter media with the desired properties. It is not true that the use of rolling prefilters solely to protect HEPA filters from fire-generated smoke aerosols is cost effective in every type of containment system, especially if standard fire-protection systems are available in the space. But in areas of high fire risk, where the potential fuel load is large and ignition sources are plentiful, the complication of a rolling prefilter in exit ventilation ducts to protect HEPA filters from smoke aerosols is definitely justified.
- Research Organization:
- California Univ., Livermore (USA). Lawrence Livermore National Lab.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 6949917
- Report Number(s):
- UCRL-84979; CONF-801038-5; TRN: 80-018818
- Resource Relation:
- Conference: 16. DOE nuclear air cleaning conference, San Diego, CA, USA, 20 Oct 1980
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AIR FILTERS
EQUIPMENT PROTECTION DEVICES
FIRE RESISTANCE
HOT CELLS
VENTILATION SYSTEMS
CONTAINMENT SYSTEMS
DESIGN
FIRE PREVENTION
FIRES
PERFORMANCE
SAFETY
CONTAINMENT
ENGINEERED SAFETY SYSTEMS
EQUIPMENT
FILTERS
LABORATORY EQUIPMENT
POLLUTION CONTROL EQUIPMENT
420202* - Engineering- Protective Structures & Equipment