To layout cake filtration applications specific knowledge of the used filter media is required which interacts with the prevailing particle systems. For the reliable determination of characteristic properties such as the filter cake and the filter medium resistance, corresponding laboratory tests are necessary, which are carried out with the pressurized filter cell standardized in VDI 2762 [1].

This contribution will take a closer look at various effects relating to this measuring principle. On the one hand, it will be shown that simply adding the filter resistances when combining two or more filter media is not always correct. For this purpose, investigations are shown, which include both experimental and simulative approaches. In addition to the combination of filter resistances, initial effects at the start of the filtration measurement will also be discussed. It will be shown that the measured values of the filter media properties are generally influenced by the measuring principle used. In accordance with VDI 2762 a transparent filter cell made of polymethylmethacrylat (PMMA) was developed to better illustrate the aforementioned effects...

Alongside to the experimental proof of the initial effects, simulations were also carried out to illustrate these better. For this purpose, µCT images of the filter material used were taken (Figure 2) so that a two-dimensional CFD model could then be derived from the sectional images of the µCT scans (Figure 3). The simulation result for a flow with demineralized water at a differential pressure of 0.8 bar is shown in Figure 4, using a stationary simulation and considering turbulence and periodic boundary conditions...