The overall filtration process is viewed as a continuous change in the structure of the active deposition zone of a given filter layer: from the initial clean filter medium, via continuous particle deposition, to a new, dynamically preserved stable porous structure. The stable 1D deposition profile during the surface filtration can be described with a logistic function.

Abstract

The overall filtration process is viewed from a new perspective: There is a continuous, systematic change in the structure of the active deposition zone of a given filter layer, here as the so-called active filtering layer. During the overall filtration process, the filtering layer is transformed from the initial clean filter medium, via continuous particle deposition under the given filtration conditions, to a new, dynamically preserved stable porous structure, i.e. the active deposition zone on the upstream side of the dust cake. Based on 3D simulations of cake formation on model filters for fabric filters, 1D deposition profiles during the continuous filtration process are evaluated and converted into a dimensionless form, to describe the structural changes in the filtering layer. The stable 1D deposition profile during the phase of surface filtration can be well described with a logistic function.