Fundamentals Of Dust Explosions

The handling of powdered or dust-like substances, is an activity, which has been known for more than two hundred years to require a careful safety technical assessment and evaluation in order to prevent major accidents. The hazard potential related to handling such substances is their affinity to decompose either in form of a combustion or an explosion. This affinity becomes ever stronger with decreasing particle diameter. 

The literature is filled with reports on dust explosion incidents, some of them with disastrous consequences. In his book Explosions , Bartknecht provides a short historical outline of first reports describing dust explosions and milestones of their research [79]. According to this survey, one of the first reports dates back to 1785 and describes the destruction of a flour storage building. In general, most accidents occurred in either the food or the mining industry. In 1844 Faraday discovered, that coal dust is explosible. 

There is a special reason for treating this topic of process safety engineering here despite the existence of extensive literature. It is necessary to reduce the risk, which is 

However, this is a necessary but not a sufficient condition. In addition, fuel and oxidizing agent have to be mixed intensively and the fuel must have a certain concentration in this oxidizing agent. All these statements are independent of the ftict whether the fuel is a gas, a liquid or a solid. 

An oxidizing decomposition reaction and an explosion differ mainly in the reaction rate. Explosion processes proceed so fast that the combustion energy becomes visible in form of a flame. The wanning of the environment due to heat radiation will lead to a pressure rise in closed systems with all possible damaging consequences. 

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