A roller mill, having a grinding table and grinding rollers, wherein the grinding table is rotatable relative to the grinding rollers about a center axis of the grinding table in a grinding table rotation direction, such that the grinding rollers roll on a grinding track of the grinding table about a roller rotation axis. At least one of the grinding rollers is rotated to be set at a set angle in the direction of the grinding table rotation direction, such that the roller rotation axis extends at a radial distance from the center axis of the grinding table. The set angle is between 1 degree and 9 degrees. A method for operating a roller mill, and the use of a roller mill for comminuting particulate bulk material are also disclosed.

A planetary roller mill for processing a feed material includes a vessel with a grinding ring having an opening therethrough and a first area. The grinding ring is in sealing engagement with the inside surface of the vessel assembly. At least two non-circular support plates are secured to a rotatable shaft. Each plate has an axially facing surface. A plurality of rollers rotatably are mounted to and positioned between the two support plates. Each of the plurality of rollers are in grinding communication with the grinding surface. The planetary roller mill includes an air supply system having an outlet in communication with the opening in the grinding ring. Areas of the two support plates are of magnitudes which configure a flow area through the opening of at least 30 percent of the first area to provide a predetermined quantity of heated air to remove moisture from the feed material in the grinding assembly.

In a method and a corresponding device for controlling a rotational speed of a drive driving a shaft, the rotational speed is controlled by a control device which is supplied with a control deviation calculated based on a desired value and an actual value for the rotational speed. The actual value for the rotational speed of the shaft is measured on the shaft with a first sensor and at least one additional sensor and the actual value is calculated from a weighted average of the individual measured values for the rotational speed obtained from the first and the at least one additional sensor.

A planetary roller mill for processing a feed material includes a vessel with a grinding ring having an opening therethrough and a first area. The grinding ring is in sealing engagement with the inside surface of the vessel assembly. At least two non-circular support plates are secured to a rotatable shaft. Each plate has an axially facing surface. A plurality of rollers rotatably are mounted to and positioned between the two support plates. Each of the plurality of rollers are in grinding communication with the grinding surface. The planetary roller mill includes an air supply system having an outlet in communication with the opening in the grinding ring. Areas of the two support plates are of magnitudes which configure a flow area through the opening of at least 30 percent of the first area to provide a predetermined quantity of heated air to remove moisture from the feed material in the grinding assembly.

A planetary roller mill for processing a feed material includes a vessel with a grinding ring having an opening therethrough and a first area. The grinding ring is in sealing engagement with the inside surface of the vessel assembly. At least two non-circular support plates are secured to a rotatable shaft. Each plate has an axially facing surface. A plurality of rollers rotatably are mounted to and positioned between the two support plates. Each of the plurality of rollers are in grinding communication with the grinding surface. The planetary roller mill includes an air supply system having an outlet in communication with the opening in the grinding ring. Areas of the two support plates are of magnitudes which configure a flow area through the opening of at least 30 percent of the first area to provide a predetermined quantity of heated air to remove moisture from the feed material in the grinding assembly.

The present invention relates generally to Szego-type grinding mills and in particular, to an improved Szego-type grinding mill incorporating interchangeable parts.

A material processing system for processing and separating material, such as gold or rocks of desired shape and size, from undesired materials. The material processing system generally includes a base, a table rotationally coupled to the base, a drive assembly coupled to the base by a height-adjustment mechanism, and one or more wheels, such as large pneumatic wheels mounted on the drive assembly and positionable so that a portion of the outer surface of the wheels contacts the table. The table may be rotationally coupled to the base by a bearing, and may further be coupled to the bearing by a table support. Material fed onto the table may be crushed beneath the wheels or carried over a plurality of annular grooves as the table rotates, driven by one or more wheels or directly by a motor.

A method for drive control of a vertical mill having a grinding plate rotatable about the vertical axis by a drive train composed of an electric motor and a gearbox is disclosed. At least the electric motor and the grinding plate represent inertia elements in a system that can oscillate and are connected by the gearbox operating as a torsion spring element. A variation in the rotation speed of at least one of the inertia elements is measured, and the electric motor is governed by a controller that minimizes the measured variation in the rotation speed. The controller is parameterized for governing the electric motor so as to minimize maximum reaction torques resulting in the gearbox when applying a sinusoidal excitation.

A roller mill includes a shell provided with a feed port and a discharge port; a main shaft inserted in the shell and rotatable in the shell; a drive device drivingly connected to the main shaft a holder mounted on the main shaft two or more than two grinding rollers, each of the grinding rollers mounted on the holder and rotatable around its own axis; and a grinding disk fixedly mounted in the shell at a position opposite to the multiple grinding rollers. The roller mill further includes an axial position adjustment device connected to the main shaft and configured to drive the main shaft to move axially to adjust a position of the main shaft.

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 (4a), 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 (4a) with respect to a line in the direction of the radius of the grinding plate (2).