| 摘要 |
A description is provided of a method as well as an apparatus for grinding particulate material, such as cement raw materials, cement clinker or simila r materials, in a roller mill (1) by subjecting the material to pressing actio n in a zone (13) between opposite, rotating surfaces where the material is directed to the grinding zone via a feed shaft (11). The method is peculiar in that the material in the feed shaft (11) is accelerated through the action o f gravity to a desired velocity without involving essential air admixture, whereas the apparatus is peculiar in that the feed shaft is essentially of a vertical configuration, with a downwardly reduced cross-section, where the reduction of the shaftïs cross-sectional circumference per height unit is downwardly decreasing.The described configuration of the feed shaft has, surprisingly, proved that the material over a given height of fall may attai n high velocities and that this is achievable without involving admixture of a ir into the material. It has thus been established that it will be possible for the material to attain velocities which are close to the velocity achievable in connection with the free fall of individual particles.
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