| 摘要 |
The invention relates to an apparatus for mixing, drying and coating pulverulent, granular or shaped loose material in a fluidized bed, in particular for use in a process for producing supported catalysts for gas-phase oxidations, which comprises a container ( 10 ) for accommodating the loose material, with a bowl-like depression ( 17 ) being provided in a lower region ( 13 ) of the container ( 10 ), a central tube ( 27 ) for introducing a gas, with the central tube entering the container in an upper region ( 12 ) of the container ( 10 ), extending essentially axially downward in the container ( 10 ) and opening into the depression ( 17 ), an essentially annular deflection shield ( 29 ) which is fixed to the central tube ( 27 ) in the upper region ( 12 ) of the container ( 10 ), a guide ring ( 31 ) which is located in the lower region ( 13 ) of the container ( 10 ) and surrounds the central tube ( 27 ) essentially concentrically at a distance (L) for part of its length so that a first opening ( 34 ) is formed between the wall of the container ( 10 ) at the upper edge ( 22 ) of the depression and the lower end ( 33 ) of the guide ring ( 31 ) and a second opening ( 36 ) is formed between the deflection shield ( 29 ) and the upper edge ( 35 ) of the guide ring ( 31 ), and means, for example valves ( 21 ), for introducing a fluid into the container ( 10 ). In the apparatus of the present invention, the outer wall of the central tube ( 27 ) is at least partly provided with an adhesion-reducing coating ( 38 ). In a preferred embodiment, the distance (L) between the wall of the central tube ( 27 ) and the wall of the guide ring ( 27 ) is greater than the open height (H 3 ) of the first opening ( 34 ). The invention also provides a process for producing supported catalysts using such an apparatus.
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