Journal of Loss Prevention in The Process Industries, Vol.24, No.1, 63-75, 2011
Application of fire suppression materials on suppression of LNG pool fires
An LNG pool fire is considered one of the main hazards of LNG, together with LNG vapor dispersion. Suppression methods are designed to reduce the hazard exclusion zones, distance to reach radiant heat of 5 kW/m(2), when an LNG pool fire is considered. For LNG vapor dispersion, the hazard exclusion zone is the distance travelled by the LNG vapor to reach a concentration of 2.5% v/v (half of the LNG lower flammability limit). Warming the LNG vapor to reach positive buoyancy faster is one way to suppress LNG vapor dispersion and reduce evaporation rate (thus fire size and its associated radiant heat) and that is the main objective in LNG pool fire suppression. Based on previous research, the use of high expansion foam has been regarded as the primary method in suppressing LNG pool fires. However, in 1980, another method was introduced as an alternative pool fire suppression system, Foamglase (R). The research concluded that 90% of the radiant heat was successfully reduced. Currently-called Foamglase (R) pool fire suppression (Foamglase (R) PFS) is a passive mitigation system and is deployed after the leak occurs. Foamglase (R) PFS is non-flammable, and has a density one-third of the density of LNG, thus floats when an LNG pool is formed. This paper describes the study and confirmation of Foamglase (R) PFS effectiveness in suppressing LNG pool fires. In addition, while Foamglase (R) PFS is not expected to suppress LNG vapor dispersion, further investigation was conducted to study the effect of Foamglase (R) PFS on LNG vapor dispersion. An LNG field experiment was conducted at Brayton Fire Field. The experimental development, procedures, results and findings are detailed in this paper. (C) 2010 Elsevier Ltd. All rights reserved.
Keywords:Foamglas (R);Pool fire suppression;LNG safety;Pool fire;Mitigation system;Hydrocarbon camera;Field experiment