Experimental Investigation on the Collection of Fine Dust with High Resistivity by a Bipolar Discharging ESP

摘要

A new electrostatic precipitator (ESP) for avoiding the back corona of the high resistivity dust layer is developed by fixing the barb nail discharging electrodes on the plate collecting electrodes based on the analysis of the phenomenon of the back corona of the high resistivity dust layer deposited on the grounded plate electrodes. Therefore, this ESP becomes a bipolar discharging ESP because the negative ions and the positive ions are generated simultaneously by the high voltage discharging electrodes and the grounded barb nail discharging electrodes respectively. The ionic wind is measured by a Particle Image Velocimetry (PIV) because the ionic wind plays an important role in collecting the fine dust with high Resistivity. The positive and the negative ion wind velocities in core area are about 2 m/s when the distance between the opposite electrodes is 100 mm at the voltage of 3.4 kV. In our comparison experiments, the overall efficiency of the bipolar discharging ESP for collecting the silica flour with 0.159 μm mass median diameter is higher than that of the unipolar discharging ESP at the mean electric field of 3.4 kV/cm in the room temperature and pressure. The experimental observation shows that the there is no back corona in the bipolar discharging ESP even when the very high resistivity silica flour (2.4×1014 Ω·cm) is used.