Dust Explosions: The Potent Power of Powder

摘要

Something just blew up inside a plastics processing plant where a pneumatic conveyor blower was located. The damage patterns on various piping and machinery indicate that the equipment was damaged by external (not internal) pressure loading. The initially assumed dust explosion could not have happened: Dust must be confined within some type of enclosure in order to generate a particle concentration sufficient to propagate an explosion! In order to support an explosion, dust must be about 10,000 times more concentrated than normal health hazard limits. In other words, if you cannot see your hand in front of your face while standing in a combustible dust storm, you are probably inside a containment where an explosion is possible. In the above example, the initial explosion may not have been a dust explosion; however, a "secondary" explosion generated by entraining dust lying around the building could be initiated. More about this later.