Vertical roller mill application in the milling aspect well after cement has not reached the mill, which is developing rapidly and widely applied, but has evolved to the stage of practical application. By Mill as final cement grinding not only have higher demands finesse, also must have a certain particle size gradation. The fineness of the cement can be adjusted by adjusting the grinding pressure conditions; on the cement particle size gradation requirements mainly by grinding the inside and outside separator of the adjustment of the mill powder selection system. Therefore, the following two problems are the main problems of vertical roller mill cement that final grinding to resolve.
1. Stable operating fineness of cement grinding raw materials
to grind that although numerous. When there are many 2 cement grinding ~ 50 Fine particles of M, and the wind conditions, can produce a strong gasification and upward force, so the grinding roller can not effectively engage in bulk materials, destruction of the bed material is stable, which causes the vibration.
2. certain area, the narrow particle size distribution
adjusted operating Cement Grinding on the final distribution of the product size requirements than grinding the raw. The characteristics of the vertical roller mill is input each time through the grinding roller between the grinding wheel and an energetic material is very low. Therefore, to achieve the required per unit of energy, the material has to cross many times. This leads to a very high rate of internal circulation of material. If the effectively powder selection process, the high recycle rate will lead to the particle size distribution curve is very steep. Therefore need to take certain steps to reduce the particle size distribution curve of the slope to reach the cement quality in the ball mill grinding can achieve.
Main vertical roller mill companies that vertical roller mill rolls have made some modifications to overcome the two problems mentioned above cement finishing mill system.
