A simulation model of aerosol collection in granular media

Abstract

A simulation model for aerosol collection in granular media resulting from the flow of aerosol streams is proposed. The granular medium is represented by the recently proposed constricted tube model which takes into account the divergent-convergent flow characteristics of porous media and the interaction of neighboring grains. The deposition process is described by the following assumptions: (a) the aerosol particles are randomly distributed in the streams and (b) once a particle becomes collected, it may act as a collector itself, thereby leading to the formation and growth of particle aggregates as deposits. For a given set of operating conditions, the model provides detailed information about the dynamics of the deposition process including the number of particles collected, and the position of the deposited particle as functions of time. Application of the model to granular filtration design is discussed. Generally speaking, the results of the stimulation model can be used to develop a relationship between changes in collection efficiency and pressure drop and the extent of particle collection, thus making it possible to predict the dynamic behavior of the filtration process. Comparison between the model and experimental results is also presented.