Filter centrifuges are used in many industrial processes for solid-liquid separation. They can enable the filtration of small and valuable samples [1]. The compression of a filter cake can change the porosity distribution and thus increase the flow resistance, which means that a higher pressure difference is required for solid-liquid separation.

In this work the compression behaviour of particle layers, consisting of elastic-plastic microparticles, has been investigated depending on the centrifugal force using experiments and coupled CFD-DEM simulations. In an analytical photocentrifuge (LUMiSizer, LUM GmbH), suspensions of ethanol and spherical paraffin particles (100 - 250 µm) were centrifuged at different rotational speeds up to 4000 rpm and temperatures (20 - 40°C) in order to investigate the plastic deformation of the particles depending on their mechanical properties and acting centrifugal force.

By a spatially and time-resolved extinction measurement in the LUMiSizer, the change of the sediment height with increasing rotational speed was measured. The compressed sediment layers from the experiments were analysed using μCT imaging (TomoScope L, Werth Messtechnik GmbH) to determine the porosity distribution in the sediment ...

To understand the mechanics of the compression and the particle motion in a centrifuge, coupled CFD-DEM simulations were performed with a

The simulations and the experiments showed that a stronger compression of the ... is achieved with increasing speed of rotation and therefore centrifugal force. The compression occurs due to plastic deformation of the particles, which is dependent on the yield pressure. The porosity of the sediment also decreases more strongly towards ...