A Statistical Model of Pressure Drop Increase with Deposition in Granular Filters

TL;DR

This paper introduces a statistical model that explains two observed pressure drop increase patterns in granular filters based on deposit distribution, unifying their understanding and matching experimental data.

Contribution

A novel statistical model based on homogeneous and heterogeneous deposit concepts unifies pressure drop increase patterns in granular filters.

Findings

Model accurately reproduces observed pressure drop patterns.

Different deposit distributions cause distinct pressure drop behaviors.

Model shows excellent agreement with experimental data.

Abstract

As deposits accumulate in a granular filter, pressure drop across the filter bed required to maintain a constant fluid flow rate may increase. Two pressure drop increase patterns had been observed. In slow sand filters pressure drop remains unchanged for a certain period of time then increases exponentially with the volume of filtrate; in granular aerosol filters pressure drop increases linearly with the amount of deposits from the beginning of the filtration process. New concepts of homogeneous and heterogeneous depositions were introduced in this paper. A statistical model based on these new concepts was developed. This non-linear model was able to reproduce both observed pressure drop increase patterns, including the linear one. Excellent agreements between the present model and experimental measurements were obtained. It was concluded that the two pressure drop increase patterns were indeed caused by different deposit distributions rather than different pressure drop increase mechanisms.