Electrostatic charge decay and filtration performance of nonwoven filters in the vicinity of grounded metal grids.

Most studies on corona-charged nonwoven filters have used grounded electrodes during charging and surface potential measurements but not during filtration experiments. This study was focused on the investigation of a grounded metal grid effect on the filtration efficiency. The results showed that the filtration outcome strongly depends on the filter–grid distance. Moreover, the electric charge was maintained for a considerably long duration when the ground electrode was used, which led to an increase in the filtration efficiency. The efficiency exceeded 90% at a voltage of 10 kV with the grid and was <70% at 30 kV without the grid. • Potential decay and filtration performance of corona charged filters were investigated. • The effect of a grounded metal grid on the filtration efficiency was investigated. • The "filter–grid" distance affects both potential decay and filtration efficiency. • Electric charges are kept longer on the filter surface with the grid electrode. • The filtration performance was significantly improved with the grid electrode. [ABSTRACT FROM AUTHOR]