INVESTIGATION OF LOADED FIBROUS FILTER

Abstract

This paper presents results of theoretical and experimental investigations of the effect of dust deposition on filter performance. In the theoretical model, the filter is divided into elements of various structural characteristics and the effect of fibers and deposited particles on pressure drop and collection efficiency is considered. In the suggested model, the part of the deposited particles increases the diameter of fibers, the rest form dendrites. Two dimensional flow fields in inhomogeneous filter mat are described by the continuity equation and Darcy equation. In order to obtain a clear idea about the effect of dust load on pressure drop and filter efficiency experimental investigations of clogging process in filter mats were performed where the temporal change of pressure drop and grade efficiency were measured. Theoretical and experimental results indicate that due to deposited particles the collection efficiency of filters increases rather rapidly with loading because the previously deposited particles offer additional collection surface. Deposited particles increase also the pressure drop across the filter by additional drag to gas flow. Calculations of streamlines through inhomogeneous filter mat indicate that deposited particles increase the uniformity of the flow field. The comparison of the results of calculation and experimental data on temporal change of collection efficiency and pressure drop shows considerable agreement.