Pipe and duct deflagrations associated with incinerators

The potential for dust and gas explosions in the process industries has been long recognized. Potentially explosive materials are handled in large quantities on a daily basis. A specific hazard associated with conveying materials into incinerators and thermal oxidizers involves the potential for deflagration propagation through process pipes and ducts back into the plant. The deflagration propagation phenomena in pipes and ducts is one that is both highly hazardous and complex to predict. A deflagration, moving down a pipe, under the right conditions can increase in velocity to the point when a transition into detonation occurs with potentially catastrophic results, This deflagration to detonation transition (DDT) is effected by a number of interrelated factors. Knowledge of these factors is crucial to the development of explosion prevention and protection measures. A discussion of the deflagration phenomena is presented with emphasis on pipes and ducts and transition of deflagration to detonation. The use of this information to design explosion protection is described using several industrial examples.