The report gives results of a study of the collection of charged submicron sized particles by fiber beds. Removal efficiency was determined as a function of particle resistivity, fiber bed resistivity, superficial gas velocity, and total concentration of the aerosol. Using a 12-in. thick polypropylene fiber bed, greater than 90% removal efficiency was reported for superficial bed velocities up to 300 ft/min. For a 6-in. bed, 90% removal was possible up to 200 ft/min. In both cases, the pressure drops for these systems were low (less than 1 in. H2O). A third bed was tested, comprised of a 6-in. Teflon fiber bed followed immediately by a 6-in. polypropylene bed. This composite 12-in. bed did not perform as well as the homogeneous 12-in. bed. In all tests, the most important parameter was bed face velocity. In general, the collection efficiency of the fiber bed decreased linearly with increasing velocity.

Grant no. R801581-02-2, ROAP no. 21ADL-035, program element no. 1AB012. Issued May 1977.