Vertical Roller Mill Operation

Vertical Roller Mill Operation

Vertical Roller Mill adopts a new generation of cement grinding technology, which integrates grinding, drying and powder selection. It can save 30% electricity per ton compared with traditional ball mills. At the same time, there are few auxiliary equipments, one machine is multi-functional, the floor space is small, and the dust pollution is small. It is widely used in the clinker production of cement plants and grinding stations. With such a large performance advantage, the development of vertical roller mill is very fast. Behind the rapid development, we should pay more attention to the details of vertical roller mills. For this reason, this article will give a detailed introduction to the details of the operation.

When working as a machine, it is first necessary to clarify the internal logic of the system, which requires the operator to clearly understand the characteristics of the system process and equipment. Then understand the operation of the system. What are the hidden dangers of equipment and how is the quality and quality of the equipment? Look at the full analysis report sheet to understand the grindability of the material so that it can be targeted. It is necessary to be familiar with the interface of the control system and the equipment on the field. Therefore, it is often necessary to go to the scene to understand the situation of the equipment.

Especially when a field device fails, you must know the cause of the failure and how to solve it.

The mill is a device that grinds the material using the relative grinding of the grinding roller on the grinding disc. There are several main aspects to the normal operation of vertical roller mills:

Appropriate material layer thickness and stable material layer are the basis for stable operation of the vertical roller mill. The material layer is too thick and the grinding efficiency is reduced. When the pressure difference of the mill reaches the limit, it will collapse, affecting the main motor and the external row system; the material layer is too thin, the driving force of the mill increases, and the grinding roller Both the disc and the hydraulic system are damaged.

Mill vibration. Excessive vibration of the mill will not only directly cause mechanical damage, but also affect production and quality. The factors that cause vibration are: the foundation of the mill, the grinding pressure, the thickness of the material layer, the air volume and the air temperature, the pressure of the accumulator, the wear condition of the roller surface or the grinding disc, and the like.

Grinding pressure. Grinding pressure is the main factor affecting the production and quality. The grinding pressure should be adjusted according to the size of the feeding amount of the mill, the particle size of the material, and the ease of grinding. In order to maintain a certain thickness of the material layer on the disc, reduce the vibration of the mill, and ensure stable operation, the roller pressure must be controlled. The vibration speed of the mill increases, and the damage to components increases. So maintaining a proper grinding pressure is a critical operation.

Mill outlet gas temperature. When the mill's outlet gas temperature is too low, the material's fluidity will deteriorate. The methods for increasing the temperature include: increasing the air-drawing of the mill, and adjusting the fineness by the separator; increasing the opening of the hot air damper and reducing the opening of the circulating air. These methods also apply to other types of raw material mills. However, if the temperature is too high, the equipment will be damaged. Each mill has its own adaptation temperature, and the operator must master it during operation.

The system operates safely. When raw material vertical roller mill runs, the drying heat source of the material comes from the kiln tail hot gas, so when the vertical roller mill is operated, the control of the inlet and outlet air valve should be taken into account. When the vertical roller mill inlet and outlet dampers are balanced, the system's wind balance will also be balanced, and there will be no impact on the kiln tail pressure. The operation of the mill is the focus we need to pay attention to, especially the details of the operation, we must maintain a cautious attitude.