Countermeasure for Edge Effect of Wire-Plate Electrostatic Precipitator

The breaking of discharge electrode that makes the operation of electrostatic precipitator (EP) impossible is considered to be a cause of the material fatigue due to the excessive sparkover on discharge electrode opposite the edge part of collecting plate electrode. In this paper, the optimum countermeasure for edge effect in the latter case has been determined with taking notice of the geometric structure of electrodes. As for the discussion of the edge effect, the corona current density distributions on collecting and discharge electrode have been measured by the use of a divided electrode and a particular discharge electrode. Observations of corona discharge phenomena in the edge area with Schlieren apparatus have completed the edge effect measurements. The set of results indicate that the edge effect is lowered as the geometric coefficient D/R (the ratio of the space distance between active and passive electrode D to the radius of collecting electrode edge R) and the average field strength decreases. It is concluded that the countermeasure for the edge effect is sufficient if the geometric conditions which D/R is less than equal to 1 are satisfied.