Prevention of incendiary discharge in a silo by using a newly developed electrostatic eliminator

In order to prevent incendiary electrostatic discharges from occurring in silos used for pneumatic transportation of powders, the performances of a newly developed electrostatic eliminator have been evaluated using an experimental facility. The eliminator consists of eight ionizing needle electrodes of the air nozzle-type attached to the end of the silo inlet pipe. AC or DC high voltage is applied to the ionizing electrodes by resistance coupling to eliminate the static charge on the powder entering the silo. DC high voltage is found to be more effective than AC in terms of static elimination performance. However, it has the problem of reverse charging of the powder in cases where the applied voltage is uncontrolled. Experimental details are described in this paper.