Résumé
One of the electrode configuration mostly-used for the electrostatic charging of filtration media is the dual wire-cylinder electrode. If the charged zones are not well controlled, electric discharges may occur and endanger the equipments (electric or electronic) near the electrode.
This paper presents the numerical calculation of the electric field and space charge density generated by a dual wire-cylinder electrode to which a limiting metallic cylinder was attached. The role of this additional electrode is to reduce the area on which the charge generated by the ionizing wire is collected at the surface of the grounded electrode and hence to increase the charge density in the active zone of the device. The numerical results confirm the fact that the charge is confined to a smaller volume and its density is higher when attaching this cylinder to the standard dual electrode. A simple experiment validated the theoretical predictions and the numerical simulations.