| 摘要 |
1385907 Making catalyst supports; extrusion IMPERIAL CHEMICAL INDUSTRIES Ltd 27 April 1972 [7 May 1971] 13721/71 Heading B5A [Also in Division B1] A catalyst support comprising a multitubular refractory module in which the tube axes are mutually parallel is formed by forcing a plastic composition through a primary zone of a plurality of channels in a solid block and then through an outlet zone of intersecting slots in the same block, the slots being in the form of straight lines and/or continuous curves transverse to the direction of flow of the composition, the aggregate cross-sectional area of the slots being sufficiently less than that of the primary zone channels and the time of passage through the slots being sufficiently long to unify the feed into a module which is dried and calcined to form ceramic bonds. The composition comprises either the material of the support or a compound thermally decomposable or reactable thereto, a liquid and a viscosity-controlling substance soluble in or swellable by the liquid. As shown in Figs. 1, 2, the die comprises a block 10 having circular-section primary zone channels 12 and intersecting slots 14 in the outlet zone. Slots 14 are formed by saw-cutting along mutually perpendicular sets of parallel lines, channels 12 being bored in line with the intersections thereof. The plastic composition may comprise any oxide having the desired refractory properties, e.g. an hydraulic cement and a finely divided aggregate, e.g. low-silica aluminous cements and, as aggregate, alumina, titania, zirconia, mullite or calcined kaolin; clay, refractory spinels &c. are also specified. The catalytic constituent may be a Group VIII metal, e.g. nickel, cobalt or a platinum group metal or metal oxide e.g. for non-oxidative treatment of internal combustion exhaust gases. A ceramic binding agent may be bentonite or another water-swellable clay. A soluble or swellable organic polymer may be starch, a cellulose ether or ester, a polyvinyl alcohol, ester or ether or a protein, the extruded module being calcined to decompose or burn out such polymers. |
