Electrostatic discharge pattern and energy probability distribution of different polarity powders in industrial silo

Understanding the electrostatic discharge behavior of the charged powder is significant for avoiding fire or explosion in the silo. The electrostatic discharge of different polarity powders is not fully revealed, especially for the discharge pattern and the discharge energy distribution. In this study, the electrostatic discharge of different polarity powders during the filling process was examined to explore the discharge behavior in an industrial silo. The results show that the discharge of positively charged powder was compact and the discharge of negatively charged powder was divergent. The point, linear and dendrite discharge were found in the positive charging process. The discharge position and development process of different polarity powders were revealed by the electric field simulation. The relationship among the discharge period, powder polarity and heap surface area were indicated. The probability density distribution of discharge energy on the powder heap surface of 2.7 m was proposed to thoroughly understand the discharge energy of charged powder in the silo. The discharge of positively charged powder might induce more energy release, which was more dangerous than that of negatively charged powder in the silo.