Passive Means to Prevent Explosions

The term explosion in a storage and handling sense usually implies the rupture of a vessel. Fauske [191] reviewed the hazards in the chemical industry in connection with storage and processing of chemicals. The major hazards discussed are a boiling liquid expanding vapor explosion (BLEVE) for high- 

The conditions that promote a BLEVE are external fires heating up the tank walls above the liquid surface. This heating weakens the tank wall surrounding the vapor phase leading to a rupture. The released liquid flashes and ignites, resulting in a huge fireball. 

Following are some examples of passive safety systems to reduce the likelihood of explosions in storage units. The use of baffles in a high-pressure storage vessel can cool the tank wall above the liquid surface via liquid pumped around by vapor bubbles, extending the time for fire fighting. Fire resistant tank insulation is also effective in delaying a BLEVE. 

A solution to safe high-pressure storage is the double-walled tank [191]. The space between the two walls is filled with water, provided the stored substance is not sensitive to water in case of a leakage. A relief valve pipeline ends beneath the water surface so that either absorption or entrainment of the vapor takes place. The water-filled section of the tank has an open vent to the atmosphere. 

These proposed passive safety systems minimize the need for active safety installations in storage, such as the provision of water cooling or water curtains. 

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