Principles of particle separation in ceramic deep foam filters based on a water model

D. Hoppach*, U.A. Peuker, Technical University Bergakademie Freiberg, Germany

Deep foam filters are commonly used for metal melt filtration, to remove the particle contamination, which is inherently formed from slag material. These particles are separated from the liquid metal in the inner filter geometry of a highly porous ceramic foam filter. Already small amounts of impurities within the metallic material will cause a sudden component failure in for instance highly-stressed components made of steel in machine constructions, thin-walled aluminium plates for automotive industry or electrically conductive connections in power engineering. Therefore the collaborative research centre 920 „Multifunctional filter for metal melt filtration – a contribution to Zero Defect Materials“ deals with the filtration of metal melt.

The studies are carried out on a specially developed pilot plant using a water-based model suspension. Since the inorganic particles and the metal melt show a special wetting behaviour with contact angles above 100° the particles and the filters used in the model system have to be surface modified to correspond to a real metal melt system. Thus, hydrophobized particles are dispersed in the water to represent a typical melt with the included impurities. Both, the particles as well as the filters are composed of aluminum oxide.

The aim for liquid metal filtration is to reduce the particulate load in the melt by one order of magnitude in the size range of 20 -100 µm. This corresponds to a separation efficiency of 90% in this interval. In the investigations the length of the filter structure as well as the pore size are varied. This is done by connecting several individual filters in series. One interesting finding is, that the filtration efficiency....

Session: L9 - Depth Filtration and Adsorption - Applications
Day: 14 March 2018
Time: 13:00 - 14:15 h

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