A method for grinding a grinding material in a mill including a grinding body and at least one roller which rolls on the grinding body under a grinding pressure, wherein the grinding material is fed in a stream of grinding material, forms a grinding bed between the grinding body and the roller and is crushed in the grinding bed by the roller, wherein a grinding bed height of the grinding bed between the grinding body and the roller is continuously measured, and wherein the mill is controlled based on control variables to achieve a predetermined nominal condition, wherein the control variables include at least the grinding pressure and the stream of the grinding material and the nominal condition includes at least one nominal value for the grinding bed height, wherein a mechanical condition of the roller and therefrom a stability of the grinding bed are continuously determined.

A method for grinding a grinding material in a mill including a grinding body and at least one roller which rolls on the grinding body under a grinding pressure, wherein the grinding material is fed in a stream of grinding material, forms a grinding bed between the grinding body and the roller and is crushed in the grinding bed by the roller, wherein a grinding bed height of the grinding bed between the grinding body and the roller is continuously measured, and wherein the mill is controlled based on control variables to achieve a predetermined nominal condition, wherein the control variables include at least the grinding pressure and the stream of the grinding material and the nominal condition includes at least one nominal value for the grinding bed height, wherein a mechanical condition of the roller and therefrom a stability of the grinding bed are continuously determined.

A planetary roller mill for processing a feed material includes a vessel with a grinding ring having an opening and a first area. The grinding ring is in sealing engagement with an inside surface of the vessel. At least two non-circular support plates are secured to a rotatable shaft. Each plate has an axially facing surface. A plurality of rollers are rotatably 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 configuring 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 mill.

A method and a device for controlling the drive of a vertical mill having a grinding plate rotatable about the vertical axis are disclosed. The grinding plate can be driven by an electric motor and a drivetrain with a gearbox. An actual rotational speed and a drivetrain torque with respect to the drivetrain are detected and are fed to a control device together with a specified target rotational speed. The control device generates an output signal for a target torque based on the actual rotational speed and the target rotational speed and based on the drivetrain torque such that the resulting target torque is reduced or increased in the same direction as a torque resulting from the milling process.

A segmented grinding ring for centrifugal vertical roller mills is provided. The segmented grinding ring includes multiple cast segments which may be vaulted together using pin rods and shims to form a continuous ring. The segmented grinding ring enables the manufacture of the segments in a cast composite material.

A segmented grinding ring for centrifugal vertical roller mills is provided. The segmented grinding ring includes multiple cast segments which may be vaulted together using pin rods and shims to form a continuous ring. The segmented grinding ring enables the manufacture of the segments in a cast composite material.