Impregnated ceramic riser tube and method of manufacturing same
AssigneeBlasch Precision Ceramics, Inc.
InventorsMatthew T. Gardner, David A. Larsen
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Abstract
A riser tube for transfer of molten metal therethrough, including a porous ceramic substrate having a hollow cylindrical structure and ceramic impregnant material penetrating into pores of the substrate and plugging at least a portion of the surface pores thereof, to improve gas impermeability of the substrate. According to the present invention, the porous ceramic substrate is immersed in impregnation media containing ceramic particles, the impregnation media is subjected to an elevated pressure such that the media penetrates the pores of the substrate, and the impregnated substrate is then fired, whereby the ceramic particles form a ceramic impregnant material that plugs at least a portion of the surface pores of the substrate.
Claims17
A riser tube for transfer of molten metal, comprising:
- a porous ceramic substrate having pores including surface pores, said substrate having a hollow cylindrical structure;
- and
- ceramic impregnant material penetrating into pores of the substrate and plugging at least a portion of the surface pores of the substrate, thereby improving gas impermeability of the substrate.
A method for forming a riser tube, comprising;
- immersing a porous ceramic substrate in impregnation media containing ceramic particles, said substrate having a hollow cylindrical structure and having pores including surface pores;
- subjecting the impregnation media to an elevated pressure such that the impregnation media penetrates the pores of the substrate;
- and
- heating the impregnated substrate, whereby the ceramic particles form a ceramic impregnant material that plugs at least a portion of the surface pores of the substrate.
Dependencies are inferred from the claim text.