Electrostatic precipitators (ESPs) are widely applied to reduce particle concentrations. However, the performance of ESPs is impaired in the nanosized diameter range due to the difficulty in electrically charging these particles. The present work evaluated the inclusion of a wire screen, perpendicular to the airflow, as an additional collecting electrode of a single-stage wire-plate ESP containing two collecting plates and a single discharge wire. ESP performance was evaluated in terms of voltage, air velocity and electrode positioning in relation to the beginning of the collecting plate (inlet spacings of 1.5, 10 and 23 cm). When compared to theoretical prediction, the penetration results presented a decay for larger particles not predicted by the diffusion battery model. It was observed that the inclusion of the wire screen increased the removal of ultrafine particles and that the overall collection efficiencies increased up to 70% in the operating conditions evaluated. Moreover, the central positioning of the electrodes (inlet spacing of 10 cm) achieved the highest collection efficiencies at high voltages, but the final positioning (inlet spacing of 23 cm) presented a better performance at higher air velocities. Therefore, the wire screen can be an alternative to enhance nanoparticle collection.
ANDRADE et al. (Wed,) studied this question.