Didier-werke Ag

Peter Jeschke

Ernst Luhrsen

Hartmut Kainer

Axel Eschner

Blagoje Levkov

Gunter Gelsdorf

Siegfried Pohl

Jurgen Plath

Rudolf Ganz

Ingo Elstner

Ludwig Wirth

Hermann Leupold

Werner Richter

Rudiger Buschmann

Ortwin Rave

Martin Kienow

Gerd Willmann

A quadrangular catalyst block having a plurality of through-going slots separated by intermediate walls, each of the slots having first and second characterizing dimensions, with one of the characterizing dimensions being significantly greater than the other.

Catalyst block

The invention relates to a ceramic molding which is manufactured from high-temperature resistant, fire-resistant or refractory fibers and fine-grain, fire-resistant or refractory materials and, in certain cases, from other customary additives. The ceramic molding is characterized by the fact that its porosity gradually and continuously increases along an axis of the molding from less than 20% to more than 70%. The areas with low porosity comprise the fine-grain, fire-resistant or refractory materials. The areas of high porosity comprise ceramic fiber, such as, fibers of Al.sub.2 O.sub.3, SiO.sub.2, ZrO.sub.2, C, SiC or mixtures thereof. The intermediate areas are constructed of mixtures of ceramic fiber and fire-resistant or refractory materials. The invention also relates to the use of such a ceramic molding method for the manufacture of compound moldings saturated or infiltrated with organic resins, pitch, tar, metals, metal alloys or glasses.

Method of ceramic molding which produces a porosity gradient and the

A refractory article for casting of liquid melts, especially steel, fabricated from a mixture of Al.sub.2 O.sub.3, graphite, a flux component, a synthetic resin binder and a metallic powder. The flux component contains a first flux with a melting point from 550.degree. to 900.degree. C. and a second flux that becomes active in the mixture in a temperature ranging from 1350.degree. and 1550.degree. C. The refractory article need not be heated before use, and the carbon contained therein, which determines the strength of the article, is retained for a much longer period during use, so that the article will have a long service life.

Refractory article suitable for casting molten metal

A sliding closure unit for selectively discharging liquid melt from a liquid melt container includes a stationary refractory plate and a sliding refractory plate, the two refractory plates having complementary, abutting relative sliding surfaces. The stationary refractory plate consists essentially of a substantially non-wettable material having a Mohs' hardness of from 1 to 2, a thermal conductivity of greater than 40 W/km at 700.degree. C. and a crushing strength of not greater than 25 N/mm.sup.2 at about room temperature. The sliding refractory plate consists essentially of a substantially non-porous material having a Mohs' hardness of from 6 to 7, a thermal conductivity of less than 3 W/km at 700.degree. C. and a crushing strength of greater than 300 N/mm.sup.2 at approximately room temperature.

Sliding closure unit

An electrically heated valve element for sliding type valve joints in the outlet of a molten metal vessel has an electrical heating conductor disposed predominately in the outlet closing surface section of the valve element so that when moved to the casting position where the molten metal flow passage aligns with the flow passage from the vessel, the outlet closing surface of the element is maintained at a uniformly high temperature so that any cooling down of the outlet closing surface is avoided. The valve element is made by embedding the heating conductor which is air annealed nichrome wire in spiral form, into the refractory material of the valve element by vibration, the embedding mass being free of organic substances, carbon, sulfur, metallic iron, alkalies and/or electrically conductive substances.

Valve element for sliding type valve joints on the outlet of vessels

A refractory plate for use in slide closures for metallurgical vessels includes a basic plate element adapted to face a liquid metal melt. The basic plate element is formed of a moldable refractory concrete material including 70 to 95% by weight of alumina and 5 to 30% by weight of a cement containing approximately 80% by weight alumina. Alternatively, the 70 to 95% by weight of alumina may be replaced by an alumina-containing raw material containing more than 70% by weight of alumina, for example at least one raw material selected from the group consisting of sintered bauxite, synthetic mullite, corundum, and grinding disk fragments. The basic plate element has embedded therein a ceramic oxide insert having a cold bending strength higher than 300 kp/cm.sup.2, a hot bending strength at 1500.degree. C. higher than 40 kp/cm.sup.2, a cold compressive strength higher than 2000 kp/cm.sup.2, and a permeability to gas lower than 1.0 nanoperm. The basic plate element and the insert have extending therethrough a throughflow opening. The width of the insert, in a direction transverse to the direction of movement of the refractory plate, is from 1.3 to 3.5 times the diameter of the throughflow opening.

Refractory plate for slide closures of metallurgical vessels

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Walluf, Germany

Peter Jeschke