Diffusion Deposition of Nanoparticles in a Layer of Granules

Abstract

The deposition of aerosol nanoparticles has been studied in a model granular filter composed of parallel monolayers of contacting spherical granules with a square packing, where each even monolayer is shifted in its plane relative to an odd layer by the granule radius in two directions normal to one another. The monolayers of the granules are oriented normal to an incident flow. The efficiencies of diffusion collection of point particles by the granules have been calculated as depending on the distance between the layers in the regime of a three-dimensional gas flow at small Reynolds numbers $$\operatorname{Re} $$ $$ \ll $$ 1 within a Peclet number range of $${\text{Pe}}$$ = 102−104. The calculation results have agreed with the published data and the results of measuring the deposition of monodisperse nanoparticles from nitrogen and helium upon filtration through layers of monodisperse metal spheres. The possibility of using a layer of granules as a diffusion battery for measuring the sizes of aerosol particles has been discussed.