The report gives results of testing a novel scrubber, the Cleanable High Efficiency Air Filter (CHEAF), as part of a program to identify novel high efficiency fine particle control devices. The scrubber was tested at room temperature, using iron oxide aerosols of concentrations near 0.2 g/cu m (0.1 grain/cu ft), mass median aerodynamic diameter of 1.1 micrometers. Inlet and outlet samples were taken with cascade impactors, total mass filters, a condensation nuclei counter, and an optical particle counter. These tests were performed with different filter media, at different face velocities, and at different water spray rates and water recycle rates. Efficiency increased with increases in: foam pores per inch, pressure drop, flow rate, spray rate, and make-up water addition. The results were consistent with the hypothesis that impaction is the major collection mechanism and re-entrainment contributes substantially to penetration. Total mass efficiency was approximately 95 percent at normal conditions, for which the pressure drop across the CHEAF was 80 cm (31.5 inches) WC. The particle aerodynamic cut diameter, for which the efficiency would be 50 percent at these conditions, was determined from cascade impactor data to be below 0.5 micrometer. This indicates that the 50 percent cut diameter for the CHEAF is smaller than for a venturi scrubber operating at the same pressure drop.

"EPA 600-2-76-202." "July 1976." Cover title. Prepared by GCA Corporation, Bedford, Ma., under contract no. 68-02-1487, ROAP no. 21ADL-004, program element no. 1AB012. Includes appendices. Includes bibliographical references (page 65).