Considerations of Suitable Grounded Electrode Length of Pre-charger in Two-stage-type Electrostatic Precipitator

The two-stage-type electrostatic precipitator has been used for limited applications. It is required to have a compact size and relatively large flow rate. The two-stage-type electrostatic precipitator consists of a pre-charger and a collecting unit. The grounded electrode length in the pre-charger is generally designed to be short. In our previous studies, regarding the influence of the grounded electrode length in the pre-charger on the collection efficiency, it has been considered that the particle charge through the pre-charger decreased for a very short or very long grounded electrode length in the pre-charger. And therefore, the electric field and space charge distribution were calculated for various grounded electrodes length using a finite-element method. In the case of a very short grounded electrode, the electric field intensity around the high voltage wire electrode decreased. Additionally, the electric field intensity distribution at proximity to the grounded electrode has two additional peaks due to the effect of the edges of the grounded electrode. For the very long grounded electrode, the space charge distribution and the peak of the electric field intensity distribution did not overlap. These results show that there is a suitable length for the grounded electrode of the pre-charger for particle charging.