Apparatus and method for grinding lumpy material
The object of the invention is an apparatus and a method for grinding lumpy material. The solution according to the invention comprises a grinding plate ( 2 ) rotating on the horizontal plane around a vertical axis of rotation, onto the top surface of which the material ( 3 ) to be ground can be fed, and on the top surface ( 8 ) of which grinding plate is a plurality of grinding discs ( 4 a ), which rotate by the effect of the rotating motion of the grinding plate ( 2 ) and compress the material to be ground against the grinding plate ( 2 ). The apparatus comprises a revolver mechanism for changing the angle of the plane of rotation (RP) of the grinding discs ( 4 a ) with respect to a line in the direction of the radius of the grinding plate ( 2 ).
1 . An apparatus configured for grinding a material, wherein the apparatus comprises a grinding plate rotating around a vertical axis of rotation on a horizontal plane, wherein the material can be fed onto a top surface of the grinding plate, wherein on the top surface of the grinding plate is a plurality of grinding discs which are configured to rotate by effect of a rotating motion of the grinding plate and compress the material to be ground against the grinding plate, wherein the apparatus further comprises a plurality of grinding disc units, wherein each of the plurality of grinding disc units comprises one or more grinding discs of the plurality of grinding discs, wherein each of the grinding disc units is suspended on a vertical drive shaft and a horizontal shaft, wherein the vertical drive shaft is parallel with the vertical axis of rotation of the grinding plate, wherein the apparatus comprises a revolver mechanism configured for changing an angle of a plane of rotation of the grinding discs by turning the horizontal shaft and the grinding discs around the vertical axis of rotation of the grinding disc units in a horizontal direction with respect to a line in a direction of a radius of the grinding plate.
2 . The apparatus according to claim 1 , wherein the revolver mechanism is configured for revolving the vertical drive shaft around its vertical center axis for changing the angle of the plane of rotation of the grinding discs.
3 . The apparatus according to claim 1 , wherein each of the grinding disc units comprises an additional revolver mechanism driving the vertical drive shaft of each of the grinding disc units, independently or synchronously with other vertical drive shafts, for revolving the vertical drive shaft of each of the grinding disc units around its vertical center axis for changing the angle of the plane of rotation of each of the grinding discs.
4 . The apparatus according to claim 1 , wherein the apparatus comprises a plurality of pressing mechanisms configured for producing compressive force, the compressive force being arranged to press the grinding disc units towards the top surface of the grinding plate.
5 . The apparatus according to claim 4 , wherein the compressive force of the pressing mechanisms is arranged to press the grinding disc units towards the top surface of the grinding plate from the horizontal shaft of the grinding disc units via the vertical drive shaft.
6 . The apparatus according to claim 1 , wherein the plane of rotation of the grinding discs is vertical.
7 . The apparatus according to claim 1 , wherein the one or more grinding discs are mounted on bearings on the horizontal shaft.
8 . A method of operating the apparatus of claim 1 , the method comprising feeding the material onto the top surface of the grinding plate, rotating the grinding plate such that the material is compressed against the grinding discs, changing the angle of the plane of rotation of the grinding discs with respect to the line in the direction of the radius of the grinding plate with a revolver mechanism, and creating a grinding friction force between the grinding discs and the grinding plate.
9 . The method according to claim 8 , wherein the plane of rotation of the grinding discs is revolved around the vertical axis of rotation of the plurality of grinding units.
10 . The method according to claim 8 , wherein when revolving the plane of rotation of the grinding discs around the vertical axis of rotation, the plane of rotation is kept perpendicular to the horizontal plane of the top surface of the grinding plate.
11 . The method according to claim 8 , wherein the plane of rotation of the grinding discs is revolved by the vertical drive shaft of the grinding discs via the revolver mechanism connected to the vertical drive shaft.
12 . The method according to claim 8 , each wherein the vertical drive shaft is revolved around its vertical center axis independently or synchronously with other vertical drive shafts.
13 . The method according to claim 8 , wherein the grinding discs are pressed against the top surface of the grinding plate via pressing mechanisms producing compressive force.
14 . The method according to claim 8 , wherein a grinding friction force is exerted on the material to be ground between the grinding discs and the top surface of the grinding plate by revolving the plane of rotation of the grinding discs and/or by pressing the grinding discs against the top surface of the grinding plate.