Controlling Parameter of Vertical Mill

1. Differential pressure: It is a reflection of the mill feed size. Differential pressure fluctuation will lead to an unstable system, mainly is reflected on the following aspects: the higher differential pressure is, the more material in mill. With the unstable ventilation system, the internal and external circulation increases, causing the vibration. (With the large thickness, the current of reducer increases and the bearing vibration fluctuations is large.) We can reduce the volume of feed, adjust the ventilation quantity, and increase the grinding pressure to ease the differential pressure fluctuation. Only the stable pressure is beneficial to improve the volume of feed.

2. Mill vibration: It is the dominant factor affecting the feeding volume and operation rate, mainly manifested in: unstable material layer (too high or too low), the large granularity of materials, poor grindability, easy to vibrate when the iron enters into the mill. It’s required to adjust the thickness of material, control the ratio of material. (Adjust the rotate speed and blast volume )

3. Temperature at mill outlet; Outlet temperature variation reflects the residence time of material in the mill, in the condition of same feeding volume, mainly in: when the temperature at mill outlet is too low, grinding material thickness in mill increases. The main motor of the mill has large power consumption, while too thick material layer can cause vibration and then differential pressure fluctuates, which is not conducive to improve feed; If the outlet temperature is too high, it will result in material thickness thinning, destroy the abrasive layer. Generally, it’s required to adjust the recirculating air, the opening of cold air damper, water spray in the mill to control the outlet temperature of the mill.

4. Grinding pressure: The grinding pressure has a great influence on the feeding volume, mainly reflects on: When the grinding pressure is too low, the material on the disc cannot be grinded effectively. Many of the coarse particles cannot be grinded, splitting much slag and differential pressure rises, therefore the feeding volume cannot be improved. To increase the grinding pressure, the finished product ratio of raw material will rise and the amount of slag will be reduced, which will be beneficial to improve the feeding volume. Note: The grinding pressure cannot be set too high, because it will cause the damage of grinding roller, disc wear and hydraulic station.
5. Ventilation rate; As the power source of elevating the raw material in the mill, the ventilation quantity has a notable impact on the feeding volume, mainly reflected on: If the ventilation rate is small, the large amount of raw material in the mill cannot be extracted, resulting in increased internal and external circulation, raised differential pressure and even the serious jam. Under this situation, it required to increase system pumping power, reduce external circulation to improve the feeding volume.