Diffusion Deposition of Aerosol in Fibrous Filters at Intermediate Peclet Numbers

The diffusion deposition of monodisperse submicrometer aerosol particles in model and real fibrous filters was measured for the Peclet number range 0.1–10. The model consisted of a grid of parallel cylinders and a fan filter. The real filters consisted of ultrathin fibers with diameter of 0.16 μm. Particle deposition occurred with appreciable gas slip near the fiber surface (Kn ∼ 1). A formula based on diffusion boundary layer theory was shown to be applicable to the calculation of particle deposition in highly porous fibrous filters down to Pe ∼ 0.5.