Working Principle of Vertical Mill

Vertical mills have become an essential piece of equipment in the powder - making industry due to their high - efficiency and energy - saving features. Understanding their working principle is the key to appreciating their advantages over other milling equipment.

The working process of a vertical mill mainly involves four steps: material feeding, grinding, powder selection, and discharging.
 

Material Feeding

The raw materials, which can be various minerals, coal, or other solid materials, are fed into the mill through a dedicated feeding device. The feeding device is designed to ensure a continuous and stable supply of materials. For example, in a coal - grinding vertical mill, coal is evenly conveyed into the mill by a belt conveyor or a screw feeder.
 

Grinding

Once inside the mill, the materials fall onto a rotating grinding table. The grinding table rotates at a constant speed, generating centrifugal force that causes the materials to move radially outward towards the edge of the table. Meanwhile, several grinding rollers, which are pressed against the grinding table by hydraulic or spring forces, roll over the materials. The high - pressure contact between the rollers and the table crushes and grinds the materials into fine powder. This mechanical grinding process is highly efficient and can achieve a high degree of pulverization.
 

Powder Selection

After grinding, the powder - air mixture is carried upward by the rising airflow in the mill. In the upper part of the mill, there is a powder - selection device, usually a classifier. The classifier can adjust the fineness of the finished powder by changing the rotational speed of its blades. Coarse particles are separated and fall back to the grinding table for re - grinding, while fine particles that meet the fineness requirements are carried out of the mill by the airflow.
 

Discharging

The fine powder carried out of the mill by the airflow enters a dust - collecting system. In the dust - collecting system, such as a bag filter or an electrostatic precipitator, the powder is separated from the air and collected as the final product. The purified air is then discharged back into the atmosphere or recycled into the mill system.

In conclusion, the working principle of a vertical mill combines mechanical grinding, pneumatic transportation, and powder - selection technologies. This integrated design enables it to operate with high efficiency, low energy consumption, and excellent product quality control, making it a preferred choice in modern powder - making processes.