New Method of Decreasing the Oil Surface Potential in a Tank with an Electrostatic Screener

The discharging effectiveness of 100 and 200 mesh stainless screens fixed on top of a diffuser at the oil inlet to a 40 and 500 liter test tank is evaluated. To study the discharging mechanism in detail, the potential distribution along the axis of the test tanks, the ground current at each section of the oil - flow system, and the potential on the oil surface of the test tanks were measured. It was found that the peek potential along the axis of the tanks and the surface potential of the oil in the tanks was considerably reduced when either the 100 or 200 mesh screens were fitted. The screens were found to have some discharging effectiveness and lowered the potential not only on the surface but in the oil by reducing the oil velocity and changing the distribution of the charge density.