The report gives results of experimental measurements (in fixed- and moving-bed filters) of the effect of electrostatic augmentation on granular bed filter particle collection efficiencies. Experimental findings included: (1) either polarizing the bed or charging the particles significantly increased the collection efficiency of the filter (efficiency increased with increasing applied voltage across the bed); (2) both polarizing the bed and charging the particles caused the bed to become very efficient in collecting particles (efficiency of a 15 cm deep bed of 1.6 mm diameter alumina spheres with a polarizing field strength of 1.31 kV/cm was above 98% for all particle sizes); (3) polarizing the bed and/or charging the particles has no effect on pressure drop across a clean bed; (4) a filter cake increases the collection efficiency of the granular bed filter (the increase depends on the cake structure and the amount of dust retained in the beds); (5) DC polarization is much more effective than low frequency AC polarization; and (6) fixed bed filters show a higher collection efficiency and a higher pressure drop than moving beds (in moving beds, lower recirculation rates also have lower rates of attrition of retaining grids and granules and lower rates of dislodging and reentraining the collected particles).

"A.P.T., Inc." "February 1980." Bibliography: p. 45. "Contract no. 68-02-2183, program element no. EHE624A."