The Deposition of Aerosol Submicron Particles on Ultrafine Fiber Filters

Abstract

The diffusion deposition of submicron aerosol particles of a finite size on a model filter composed of parallel ultrafine fibers with a radius comparable with the mean free path of air molecules was considered. The diffusion capture coefficient with allowance made for particle interception ηDRis found by the numerical solution of the elliptic equation of steady-state convective diffusion in the wide ranges of interception parameter R, Peclet (Pe) and Knudsen (Kn) numbers at small Reynolds numbers. It was shown that, at small Kn numbers, the ηDR value exceeds the sum of capture coefficients due to specific deposition mechanisms, interception and diffusion, ηΣ = ηR + ηD, whereas, at Kn > 1, ηDR ≤ ηΣ. Within the range of intermediate Pe, Kn, and R numbers, the radius of the most penetrating particles is higher than the fiber radius.