The back-Corona phenomenon is specific for high resistance dust and consists in a series of micro-discharges (sparking effect) between the particles from dust layer ( dust cake) on the collecting plates. You can see the figures in the slide that show you how the voltage gradient is high in the case of resistance dust (it should be slide 32). This occurs because the dusts are hardly charged negatively.
The current-voltage characteristic of the system changes; the whole efficiency of the ESP decreases because the migration velocity depends on the collecting field strength.
The current-voltage characteristic of the system changes; the whole efficiency of the ESP decreases because the migration velocity depends on the collecting field strength.