The possible use of deep bed filter media composed of permeable synthetic collectors (PSC's) was studied. The PSC's were made of open porous plastic foam or non-woven fabrics in the shape of cylinders with dimensions of some millimeter. With such media, particle retention takes place throughout the entire body of the collectors. Theoretical analysis based on trajectory calculations for non-Brownian particles was carried out for estimating the particle collection efficiency. A parametric study was made to examine the effect of various operating variables (e.g. inner porosity and fibre diameter of the PSC's) and of particle characteristics (e.g. their size and density). In contrast to conventional deep bed filtration using impermeable filter grains, filtration using PSC's performs much better in particle collection. This conclusion was confirmed by experiments with different kinds of particles for the initial and dynamic phase of filtration. Special investigations using an endoscope showed that the adhesion behaviour of the particles inside the PSC's is getting more and more important with increasing amount of deposited particles in the collectors.

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