Boiling Liquid Expanding Vapor Explosions (BLEVE): Possible Failure Mechanisms

Abstract

Detailed re-analysis of the catastrophic failures of four 2-tonne LPG vessels subjected to jet fire attack indicates that the severity of the event and the intensity of the fireballs formed may be a function of the initiating mode of vessel failure and the thermo-hydraulic state of the contents. The mechanism of vessel failure appears to be a two-step process; the formation of an initiating overpressure crack in the high temperature vapor wetted walls of the vessel, followed by a final catastrophic ‘unzipping’ of the containment and the nearly instantaneous release of its contents. The distribution and flashing of the lading causes a fireball. The surface emissive power of the BLEVE fireball does not appear to be directly related to the ‘superheat’ of the contents at failure. Possible reasons for the final rapid failure of the vessel are either crack instability or the rapid quenching of the crack tip, due to its two phase discharge, that results in large local thermal stresses.

The boiling liquid expanding vapour explosion (BLEVE): Mechanism, consequence assessment, management

“…McDevitt et al [15], Prugh [16,17], Leslie and Birk [18], Lees [3], Birk and Cunningham [2,19], Casal et al [5] and Venart [20], among others, have given elaborate description of the occurrences which lead to a BLEVE. Based on their observations, and of Reid [21], Shebeko et al [22] and Birk et al [23], the steps involved in a typical BLEVE can be identified as under:…”

“…The size, the life, and the radiation intensity of a fireball may also depend on the temperature of the liquid lading [31], and whether the loss of confinement of the flammable material had occurred when the pressure inside was still rising [32]. The BLEVE fireballs are spheroidal when fully developed; on liftoff they acquire a mushroom-like shape.…”

Using liquid superheating energy for a quick estimation of overpressure in BLEVEs and similar explosions

“…Several researchers have published articles concerning the diverse aspects of these accidents, such as the mechanisms of explosions [1], the influence of thermal stratification [2], and the behavior of ejected fragments [3]. Our knowledge about the phenomenon has significantly improved, although not sufficiently.…”

Risks of Fire and Explosion Associated With the Increasing Use of Liquefied Petroleum Gas

“…Such fireballs can be very large, causing a very strong thermal radiation [26,27]. The size, the life, and the radiation intensity of a fireball may also depend on the temperature of the liquid lading [28], and whether the loss of confinement of the flammable material had occurred when the pressure inside was still rising [29]. The BLEVE fireballs are spheroidal when fully developed; on liftoff they acquire a mushroom-like shape.…”

“…and Birk[15], Lees[3], Birk and Cunningham[2,16], Casal et al[5] and Venart[17], among others, have given elaborate descriptions of the occurrences which lead to a BLEVE. Based on their observations, and of Reid[18], Shebeko et al[19] and Jim Smith (left) and Bill Walls who, along with Bill Marsh had introduced the term BLEVE and had given the initial explanation of its mechanism (Photo courtesy Ms Roberta, daughter of MrWalls) Birk et al[20], the steps involved in a typical BLEVE(Fig.…”