Capturing fine particles using magnetically enhanced corona pre-charger in front of an electrostatic enhancement filter

摘要

In this paper, experimental investigations on discharge characteristics of magnetically enhanced corona discharges for the purpose of capturing fine particles are presented. The discharge mechanism during such a process is analyzed. The effect of magnetic enhancement under positive and negative corona discharges was experimentally compared. The magnetic enhancement effect in different inter-electrode regions was studied. Experimental results demonstrated that magnetic field can efficiently increase the concentrations of ions and free electrons under negative corona discharge process. The dominant mechanism of magnetic enhancement in corona discharges is that the Larmor movements of free electrons enhance ionization near the discharge electrode. A reasonable configuration for magnetic enhancement was formed by permanent magnets with a local strong magnetic field near the discharge electrode. A magnetically enhanced pre-charger with negative corona discharges was assembled in front of an electrostatic enhancement filter. The influence of the pre-charger on the filter was measured and compared with that of a conventional corona pre-charger. The free electron charging mechanism of the magnetically enhanced corona pre-charger was preliminarily analyzed. The new pre-charging technology is promising for capturing fine particles in electrostatic enhancement filters or electrostatic precipitators.