Panel Bed Filters for Simultaneous Removal of Fly Ash and Sulfur Dioxide:

Experimental studies of the filtration of dilute aerosols of Dow microspheres by beds of sand have been conducted with flows passing vertically upward, vertically downward, and horizontally. With the use of Happel’s “free surface” model for a granular bed, the results can be correlated reasonably well by semiempirical, semitheoretical considerations taking into account collection by diffusion, gravity settling, direct interception, and inertial impaction. The results are preliminary to experiments to be made on filtration of aerosols by a filter cake of fly ash resting upon a sand bed.