What Is The Vertical Roller Mill?
A vertical roller mill is a type of industrial equipment used to crush or grind materials into small particles. These machines consist of a large, heavy-duty steel drum that relies on both hydraulic and pneumatic forces to pulverize rock or stone. Vertical roller mill machines are widely used in the concrete and mining fields, and are also used to process gypsum. These units can process both raw and recycled materials, while helping to reduce waste and preserve virgin supplies of these materials.
Most vertical roller mill models are positioned beneath a large hopper, which feeds rock and other materials into the top of the mill. A large, horizontal plate fits within the body of the drum, and rotates very rapidly when the machine is in use. As materials fall onto the plate, centrifugal force pushes them out towards the edges of the circular plate. Large rollers sit along the perimeter of the plate, crushing and grinding materials before they can fall off the edge. These rollers are powered by hydraulic fluid, which enables them to exert tremendous force to handle tough materials.
A pneumatic, or air-powered, system helps to collect the pulverized materials. Those that have been crushed into small particles are drawn upward via air pressure into a collection bin. Particles that are too large are heavy simply fall off the edges of the plate for reprocessing.
The vertical roller mill serves as an alternate to traditional ball roller machines. In a ball roller, grinding wheels move within a steel drum to crush rock or stone. These rollers move in a relatively random pattern, and tend to produce materials of varying sizes. They do not offer the consistency and efficient processing of a vertical roller mill. ■
Operating experience with the vertical roller mill
The main components of the vertical roller mill are the four or six grinding rollers with a cylindrical wear part geometry, the flat grinding table, the gas-guiding housing with nozzle ring and classifier and the drive, which can optionally consist of that or of a conventional drive system with planetary gear unit. All the machine components that are relevant to gas flow technology, such as the hot gas channel, nozzle ring and SLS high-efficiency classifier with the material feed are of the time-proven design.
Using the same hydraulic system that applies the grinding force during operation, the roller modules can be individually swung out of the mill. If the drive comprises a planetary gear unit, production can only be continued at reduced capacity after two opposing rollers have been lifted or swung out. The main advantage of that with its several drive modules is that it enables operation to continue even if only one roller is lifted or swung out.
Two to six identical drive modules, each with installed drive powers of up to approx.It drive the grinding table via a girth gear located under the grinding table. Each drive module consists of an electric motor, a coupling and a combined spur and bevel gear unit mounted on a base frame to form a transport unit. It is also equipped with a frequency converter, a transformer and an oil supply station.
It is a 3 section of an vertical roller mill. The designation of the mill describes the outer diameter of the grinding table, the type of material to be ground and the number of grinding rollers.The trend towards higher throughputs, i.e. larger mills, is inevitably linked with the demand for larger gear units coupled with falling mill rotational speeds. The mill performance is thus determined more by the size of the torque. To avoid problems caused by using larger and larger planetary gear units. ■