Patent ID: 7341212

Claim:
Apparatus for comminuting particulate material by inter-particle comminution in a bed of particles, the apparatus comprising: a vertical roller mill having a horizontal grinding table rotating about a vertical mill axis and a grinding track defined in the upper surface of the table, and at least two stationary, rotary-mounted grinding rollers, wherein: the at least two rollers are resiliently pressable against a grinding bed formed by the material to be crushed on the grinding table, the at least two rollers roll on the grinding bed with a pure rolling movement, the at least two rollers are one of conically and frusto-conically constructed, and the at least two rollers are positioned in such a way that the circumferential surface of each of the at least two rollers and the surface of one of the grinding table and the grinding track run horizontally and parallel to one another at a clearly defined distance wherein a common intersection point P is formed by the extended roller axes, the vertical mill axis, and a horizontal plane at height H m of the compacted grinding bed, wherein one of the height H m of the grinding bed and the corresponding point P is set in the range of 1 to 150 mm, whereby the at least two grinding rollers achieve a ground product free or at least with only a limited proportion of fines.