| dc.description.abstract | Vapor cloud explosions have caused damage, injury, and death. Typically, an explosion of this type is the result of the ignition of a flammable cloud formed by the uncontrolled release of a flammable vapor into a semi-confined and congested area. One of the principal hazards of a vapor cloud explosion is the overpressure created. The overpressure can cause structural damage and, both directly (via body translation, etc) and indirectly (via missiles, collapsed roofs, etc), injuries and fatalities. Only recently has emphasis been placed on the dramatic effect that the degree of congestion and confinement has on the magnitude and extent of the overpressure hazard. It is generally acknowledged that the greater the confinement and the greater the congestion, all other things being equal, the more damaging and potentially injurious the explosion. However, in the limit, a process area that is completely confined and completely congested, a block of solid concrete, for example, will obviously not pose a vapor cloud explosion hazard. Nor would an area that is completely filled with the "crimped metal" material that is typically used in the manufacture of flame arresters. Theoretically at least, such techniques are classified as "passive" process risk management strategies and are classified as "moderate" or "attenuation and limitation of effects" Inherently Safer Processing approaches to mitigate the vapor cloud explosion hazard. While the impracticality of using either of the above in a real process area is obvious, it is advantageous to acknowledge the fact that there is a degree of confinement and congestion above which the explosion hazard is actually lessened and to conceptualize practical techniques to take advantage of this fact. One specific method that utilizes a commercially available component and that may be practical is presented. Encouraging results from small scale tests are presented. A large scale test program is outlined, the results of which could answer scale-up design questions. | en |
