Aerosol Capture in Granular Beds in the Impaction Dominated Regime

Autor: Ted D'Ottavio, Simon L. Goren
Rok vydání: 1982
Předmět:
Zdroj: Aerosol Science and Technology. 2:91-108
ISSN: 1521-7388
0278-6826
DOI: 10.1080/02786828308958616
Popis: Single grain capture efficiencies η for high speed gas flow through clean granular beds are reported. The aerosol particles range in diameter Dp from about 0.6 to 4.5 μm; both liquid (dioctyl phthalate) and solid (potassium biphthalate) aerosol particles were used. The grains used were spheres of diameter D G equal to 2 or 4 mm and pea gravel with an effective diameter of 4 mm. The superficial gas velocity U was varied from about 0.1 to 6 m/sec. Impaction is the dominant capture mechanism for these conditions. Consequently, the Stokes number Stk = p p D p2C p U/18μD G is an important dimensionless group for correlation of the data. Because the gas flow field depends on the fraction solids αG in the bed and the grain Reynolds number Re = iD G U/μ, the single grain capture efficiency η also must depend on these two dimensionless groups. For conditions of greatest practical interest, the Stokes number is much less than unity. Theoretical considerations based on creeping flow and boundary layer flow theory su...
Databáze: OpenAIRE