| 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 similar materials, in a roller mill (1) by subjecting the material to pressing action 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 of 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 shaft´s 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 attain high velocities and that this is achievable without involving admixture of air 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. |
