Examination of Compressed Air Foam (CAF) for interior fire fighting

Weinschenk, Craig; Madrzykowski, Daniel M.; Stakes, Keith; Willi, Joseph M.

doi:10.6028/nist.tn.1927

Cited by 2 publications

(1 citation statement)

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“…For example, NRC Canada investigated the feasibility of using a fixed pipe compressed air foam (CAF) system for the protection of an aircraft hangar in place of a foam-water sprinkler system [5]. In other studies, Weinschenk et al [6] investigated the suppression capacity of CAF for interior firefighting. Overall, compressed air foam systems are used to protect equipment of various sizes because the foam expansion ratio could be regulated to combat specific fire types and sizes.…”

Section: Classification Of Occupancy Hazardmentioning

confidence: 99%

Full Scale Tests on the Discharge Characteristics, Drainage Characteristics and Fire Suppression Performance of Portable Compressed Air Foam System

Okunrounmu¹

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Existing portable foam extinguishers generate fire-fighting foam at high pressures with the aid of air aspirating nozzles. These systems could encounter several limitations at the point of application such as poor foam quality and insufficient momentum to reach the seat of the fire. Research had shown that by incorporating compressed air into the portable foam system, the integrated foam system could generate superior quality foam with high momentum when properly installed with the right components.This research investigated the discharge characteristics, drainage characteristics and fire suppression performance of a portable compressed air foam system. The study also investigated compliance with the requirements of NFPA 10 and CAN/ULC-S508 for a new portable system. Full scale tests were conducted to ascertain the results under various operating conditions.The effect of hose length on the expansion ratio of the foam was investigated with a range of parameters such as varied foam concentrate, hose lengths of 1-m to 3-m and pressure in the ranges of 2.42 bar and 5.52 bar. The foams were partially developed inside the 1-hose leading to increase in expansion ratio as the pressure increases whereas the same solutions for both 2-m and 3-m hose lengths generated fully developed foams inside the hoselines.Discharge range tests were conducted to investigate the horizontal projection of the foam. The test results showed longer projection at higher momentum in the 2-m and 3-m hose as compared to the 1-m hose. Likewise, the portable system could generate uniform and consistent foam at low pressures when the foam is fully developed inside the hose before discharge.The test results on flow rate showed that when the portable system is operated at a low rate, its application time increases thereby generating more foam for fire suppression and heat exposure ii protection without altering the consistency of the foam. Overall, all the tested foams met the requirements of the CAN/ULC-S508 standard.The drainage rate of foams with no imposed heat depends on the foam expansion ratio. The test results for the free drainage of foams showed higher drainage rate in foams with low expansion ratio in contrast to the foams subjected to thermal radiation. However, all the tested foams exhibited a similar drainage pattern, in terms of foam mass loss, at different drainage rates.Foams exposed to thermal radiation showed similar temperature profiles but disintegrated at different drainage rates. A high drainage rate was observed in foams with higher expansion ratio at the same or higher irradiance levels. Similarly, the percentage of evaporated foam and mass loss rate was greater in foams with higher expansion ratio when exposed to the same or higher irradiance levels. However, the time to half mass loss decreased with increase in foam expansion ratio and heat flux.Test conducted to determine the extinguishment ability of a portable CAF system with a 2-L capacity demonstrated that the system could extinguish 0.23 m 2 fire and 0.46 m 2 gasoline p...

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Section: Classification Of Occupancy Hazardmentioning

confidence: 99%