Exploring effect of charge dissipation in charged powder space on electric field distribution in silo

Abstract

The electric field distribution is important for understanding the underlying mechanism of electrostatic discharge in silos and for developing anti-static strategies. However, the charge dissipation of charged powder usually is not well modeled in the existing electric field simulation, resulting in inaccurate estimation of the electric field in silos. This paper studied the electric field distribution in a cylindrical silo based on the space charge density distribution created by the charged particles. The influences of the normalized filling time, gap distance, and the silo height-to-diameter ratio on the electric field were explored. The results indicate that the area with a larger space charge density shrinks from the heap bottom to the heap surface, leading to a decline in the electric field and suggesting a lower probability of electrostatic discharge at the larger normalized filling time. Continuous decrease of the gap distance when the heap surface is close to the silo ceiling will lead to a sharp increase in the electric field, regardless of the charge dissipation. The silos with a height-to-diameter ratio greater than 2 are demonstrated to have a lower probability of electrostatic discharge and a space higher utilization ratio.