During the transport of insulating powders or granules, a very high electrostatic charge may be generated. The resulting accumulation of charge in storage silos gives rise to electric fields which, when the breakdown field strength in air (3 MV/m) is reached, can lead to a cone discharge. Depending on the surrounding medium, this may result in an explosion or a fire. More exact knowledge of the electric field in silos is therefore of particular importance. However, since the methods currently in use only permit the measurement of the electric field at particular points, a mathematical model based on the finite-element method [1] has been developed to support the experiments. In close cooperation with the experimenters [2], we simulated the operating conditions, in parallel with the silo measurements. Important qualitative findings were made on the basis of the calculated field and potential distribution and energy considerations.
