Aerosol filtration by fibrous filter mats. Part III. Geometric relations

The aerosol filtration characteristics of ten randomly formed fibrous filter mats, of widely varying compositions and physical properties, were studied as a function of both the superficial linear flow velocity and the aerosol diameter size. The flow regime ranged from 7.2 to 141 cm/sec with ten discrete velocities. Four diameter sizes of dioctylphthalate (DOP) aerosol were used to challenge the filter mats over this velocity range, namely, 0.26, 0.28, 0.30, and 0.32 microns. Mathematical equations, derived from the original Dorman aerosol equations, provided insight on the interrelationships between aerosol size, flow velocity, and the diffusion, interception, and inertia mechanisms of aerosol filtration. (U.S.)