Abstract
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.