Hazards due to electrostatic charging of powders

Abstract The role of static electricity in the field of dust explosions is discussed. A general approach to the assessment of hazards and to the choice of safety measures with respect to electrostatic as an ignition source is outlined. Methods and results describing the charging behaviour of powders are reviewed. The problems to keep the charging level of powders at a safe limit are discussed and compaired to the situation for liquids. The problems and trends in the determination of the minimum ignition energy of powders as a quantity to characterize the ignition sensitivity of powders with respect to electrostatic discharges are discussed. The different types of discharges associated with the handling and processing of powders are reviewed by referring to their phenomenological and theoretical description, their occurrence in practive and their incendivity. Special regard is given to the electrostatic phenomena occuring during the filling of large containers and silos.

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