Process for manufacturing a ceramic foam body
AssigneeAlusuisse-Lonza Services Ltd.
InventorsJean-Pierre Gabathuler, Karl-Ludwig Eckert, Peter Kaser, Albert Maurer, Anton Fischer
Life of this patent
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Abstract
The process for manufacturing an open pore foam body with three dimensional ceramic network, in particular as a filter for the treatment of hot gases or as a catalyst substrate, has as its starting material a block of open pore plastic foam. This is impregnated at least once with a ceramic suspension, freed of excess ceramic suspension and heated to a temperature below the melting point of the plastic, then finally burnt off at a temperature at which the ceramic sinters together. The plastic foam block of the prescribed outer dimensions is cooled down and machined to produce a Z-flow filter with high precision longitudinal channels.
Claims20
Process for manufacturing a Z-flow filter comprising an open pore foam body with a three dimensional ceramic structure, which comprises:
- providing a soft open pore plastic foam strip;
- impregnating said foamstrip at least once with a ceramic suspension;
- freeing said foam strip of excess suspension;
- assembling a plastic foam block with a layered structure from said impregnated plastic foam strip by either (a) forming slices from said impregnated strip and stacking at least two of said slices to form layers of impregnated plastic foam including holes therein as flow channels, or (b) coiling said impregnated plastic foam strip to form layers and forming holes as flow channels between at least two of said layers;
- heating to a temperature below the melting point of the plastic;
- and
- finally burning off the plastic foam at a temperature at which the ceramic sinters together to form the Z-flow filter with longitudinal channels therein which serve as flow channels.
Process according to claim 11 wherein the block has a longitudinal direction, ends, and blind-end holes which run parallel in the longitudinal direction and serve as flow channels, said holes extend alternatingly from one end to the other end and such that the depth of the hole is at least five times as large as the smallest cross-sectional dimension and the blind-end of the hole is a distance from the neighboring end that corresponds at least to the mutual distance the holes are apart.
Process according to claim 16 wherein the holes are made at a regular distance apart in the range of 5-50 mm, and the blind-ends of the holes are a regular distance in the range of 10-50 mm, from the neighboring end.
Dependencies are inferred from the claim text.