The cake filtration is considered to be a low cost process for the continuous separation of inorganic and organic particles and also provides a very gentle product treatment. The continuous sedimentation in the centrifugal field or the precoat filtration on a vacuum drum filter is currently used for the separation of biological microparticles. Separation in a centrifugal field with a low density difference between the particles and the continuous phase requires a high centrifugal force to achieve the desired separation efficiency. Therefore a large amount of energy is required to accelerate the suspension. An alternative separation method for biological microparticles would be the cake filtration, but this method however causes a high filter cake resistance.
The aim of this project is to develop a continuous thin film filtration method for the cake filtration. In order to realize this, microporous membranes with pore diameters ranging from 0.1-1 μm will be used. Besides the advantage of a particle free filtrate, using these semipermeable membranes will result in a filtration without any gas flow rate. These semipermeable membranes ... mehrare permeable for liquids but will block the gas flow. Concerning this the characterization of the pore size distribution and the capillary pressure of those membranes are necessary. To determine the cake filtration resistance and the filter medium resistance at different pressures and different concentrations of particles in the suspension, a pressure filter device will be used. Measuring the dry mass can provide information about the dewatering efficiency of this process and allows a comparison of the different membranes at various experimental conditions and filtration resistances.