On the Extension of Mass Transfer j-Factor Correlation to the Collection Efficiency of Fibrous Filters

Abstract

Filtration of submicrometer aerosols in fibrous beds was considered as a mass transfer process. Earlier experimental data on the single-fiber collection efficiency of aerosols collected in fibrous filters were used to calculate j-factors for mass transfer. A correlation for j-factors as a function of the modified Reynold's number in the bed was developed. Comparison of the j-factors based on both experimental data and various correlations for mass transfer in packed beds indicated that aerosol filtration in the submicrometer regime possesses strong similarities to mass transfer in packed beds. Also, the experimental j-factors obtained from aerosol filtration were obtained over a larger range of void fractions of the fibrous filters (from 0.6 to 0.992) than mass transfer data and hence provide a more complete set of data to develop a comprehensive correlation.