Unconfmed vapor cloud explosion

Investigate the potential for unconfmed vapor cloud explosions resulting from accidents at the flammable storage tank area. 

Fire is more likely tlian an explosion where tliere is a loss of contaimiient of a flammable material from a railroad car, barge, ship tank, or from a pipeline. However, both unconfmed vapor cloud explosions (UVCES) and boiling liquid-e.xpanding vapor e.xplosions (BEEVES) can occur as a result of transport accidents, (see Section 7.5)... 

Tlie factors tliat affect unconfmed vapor cloud explosions arc nol well understood. In a model developed by William, it is assumed tliat ignition occurs at a point source, tliat tlie flame front travels out from tlie core at a flame speed S, and tliat tlie pressure waves produced by tlie flame generate a weak shock wave tliat travels ahead of tlie flame with a time-dependent velocity. Tlie equation for the flame speed for spherical systems is... 

Several common substances amenable to unconfmed vapor cloud explosions are hydrogen, mctliane, and liquefied natural gas (LNG). 

Unconfmed vapor cloud explosions (UCVEs) Physical vapor explosions ... 

Frank T. Bodurtha, Sc.D., E. I. du Pont de Nemours and Co., Inc., (retired) Consultant, Frank T. Bodurtha, Inc. (Gas Explosions Unconfmed Vapor Cloud Explosions [UVCEs] and Boiling Liquid Expanding Vapor Explosions [BLEVEs])... 

Davenport has listed more tlian 60 major leaks of flammable materials, most, of which resulted in serious fires or unconfmed vapor cloud explosions (UVCEs)." Table 16.3.1 classifies tlie leaks by point of origin and shows that if transport containers are excluded, pipe failures accounted for more than lialf tlie accidents. The biggest cause of tliese failures lias been shown to be poor construction due to use of wrong specifications or failure to follow specifications established. 

The initial Buncefield event, at about 6 01 a.m. was an unconfmed vapor cloud explosion of unusually high strength. The initial blast was severe enough to register 2.4 on the Richter scale by the British Geological Survey. There were two follow-up explosions at 6 27 a.m. and 6 28 a.m. The explosions were heard miles away, and... 

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