Maintaining a stable grinding table, which is the  vertical slag mill bed grinding basis, the key to normal operation. The material thickness can be adjusted by adjusting the vertical height of slag ring. The material ring is the key component of vertical mill. Its function is to maintain a certain level of grinding material. The degree of wear of the material ring affects the stable operation of the mill. Appropriate thickness and their corresponding relationship with the mill output, the operator should be mastered in peacetime operation to understand clearly: the size of the roll, the thickness of the material layer and the amount of powder between the causal relationship.

The specific context is this: the material layer is too thick grinding efficiency is reduced, the material layer is too thin will cause vibration; such as roller pressure increases, the resulting fine powder and material layer thinning; roll reduction, grinding disc material thicker, The corresponding return of more material, material thickening. Grinding wind speed increased, increasing internal circulation, material thickening, lower wind speed, reduce internal circulation, material thinning. In the continuous production practice, we concluded that the roller mill (slag vertical mill | slag vertical mill) after the roller compacted material bed thickness control in 50 ~ 60mm appropriate.

Operating staff in the operation of the process should be based on the material layer, back to the amount of vibration, vibration and other parameters to identify the material ring wear. Mill normal operation, the feeding amount of 140t / h, the vibration value of 3.0 mm / s, the amount of powder back is less than 10t. For example, a certain time, when the mill runs 4000 hours, the amount of powder back to 60-80t / h or so, vertical roller mill vibration value of 9 mm / s, the vertical mill feed gradually reduced to 100t / h, still can not Normal operation. Immediately stop grinding and into the mill inspection and measurement found that the block material ring serious wear and tear, material particles in the process of moving towards the edge of the disc suffered less resistance, resulting in the material being dumped in the disc on the shorter residence time, a substantial increase in the amount of powder back. To this end, has been worn retaining ring implementation of surfacing repair measures at the same time on the two main roller mill, separator blades to open after the maintenance of vertical mill, the production is good, the mill into and out of the material in Balanced state. For the surfacing of the retaining ring, it not only improves the service life of the retaining ring but also makes us more thorough understanding of the function of the retaining ring. That is, the gap between the retaining ring and the sleeve becomes smaller after the surfacing of the retaining ring, Particles moving towards the edge of the disc suffered higher resistance, not only to avoid the bypass material, but also to ensure that the material being grinded in the disc on the residence time