Patent ID: 8727249

Claim:
A roller mill comprising: a mill housing enclosing a grinding table and a set of rollers rotatable about a vertical shaft; said set of rollers being configured for interactive operation with the grinding table and comprising a number of rollers, each roller of the set of rollers rotating about a roller shaft which is connected to the vertical shaft via a hinged connection with a center of rotation that allows a circular movement of the roller in upward and downward directions in a plane comprising a centerline of the roller shaft; the center of rotation of the hinged connection being in a vertical plane located under the centerline of the roller shaft; the grinding table being rotatable about the vertical shaft; a plurality of gas flow devices sized and configured to introduce at least one gas into the mill housing; and at least one material diverting mechanism that continuously diverts material ground by the rollers of the set of rollers and suspended in the at least one gas out of the mill housing, the at least one material diverting mechanism comprising an outlet of the mill housing such that material is subjected to centrifugal forces due to rotation of the grinding table and rotation of the rollers so that the material is subsequently suspended in the at least one gas for diversion out of the outlet; and wherein the gas flow devices comprise two or more separate feed systems each comprising at least one fan to introduce the at least one gas into the mill housing; and wherein the at least two feed systems are comprised of a first feed system and a second feed system, and wherein the first feed system comprises at least one nozzle mounted in a wall of the mill housing to divert the ground material suspended in the at least one gas through the outlet of the mill housing and the second feed system comprises a number of nozzles arranged in a nozzle ring enclosing the grinding table that emit the at least one gas to move the ground material suspended in the at least one gas through the outlet; and wherein the at least one gas emitted by the nozzles arranged in the nozzle ring is cooler than the at least one gas emitted by the at least one nozzle mounted in the wall of the mill housing.