Study on electric field distribution in cylindrical metal silo containing charged polyethylene powder

Abstract

Understanding the electric field distribution in the industrial silo of charged powder is significant for anti-static technology. This paper investigated the electric field distribution in a bench-scale silo containing charged polyethylene powder by simulating in a finite element software. The measurement of electric field strength by the electrostatic probe was conducted to confirm the validity of this method. The influences of filling fraction (0–100%), powder heap shape (flat heap, conical heap, inclined heap, and reverse conical heap), and powder repose angle (0–60°) were assessed by this model. For four heap shapes, it was found that the position of the maximum electric field strength in the silo occurred at the heap surface, silo wall, and the heap bottom. The risk of electrostatic discharge in the silo increased as the filling fraction and powder repose angle increased. When the filling fraction was <20%, reverse conical heap and conical heap were the two most dangerous kinds of heap shapes. For a medium filling fraction (20%–80%), conical heap and inclined heap were the two most hazardous heaps. As the filling fraction increased to a high extent (>80%), the maximum electric field strength on heap surface increased sharply, indicating the higher probability of electrostatic discharge when the silo was nearly full.