High-fine limestone powder vertical mill advantage and design
The vertical roller mill uses the material bed grinding principle to grind the material, which has the advantages of large single machine production capacity, simple process flow, high grinding efficiency, energy saving and environmental protection.
The excellent performance of raw material vertical mill and slag vertical mill of chaeng has been tested by the market. The excellent performance is gradually reflected in grinding nickel slag, manganese slag, steel slag and coal slag. Grinding operation data, practical experience, theoretical analysis, combined with the material properties of limestone, we have developed a high-fine limestone powder vertical mill.
Design plan requirements:
1 Limestone powder used as desulfurizer can efficiently produce two fineness products of 5%~10% of 250 mesh sieve and 5%~10% of 325 mesh sieve;
2 Limestone powder used as concrete admixture, 325 mesh sieve residue ≤ 15%.
Through the adjustment of production parameters, the product differentiation requirements are met.
Raw material conditions for grinding:
Under the premise of no external heat source heating, the raw material moisture is ≤1.5%.
Limestone medium wearability Bond work index is about 11Kwh, particle size 95% ≤ 30mm, Max. 40mm.
Vertical roller mill design
(1) Design of grinding disc speed and grinding roller size
Vertical grinding of high-fine limestone powder, first of all to ensure the fineness of limestone powder, under this premise, consider the grinding efficiency, mill output, stabilize the bed, and run smoothly. The grinding wheel speed and the size of the matching grinding rolls are determined around these core design issues.
The high-fine limestone powder has a lower grinding speed and a larger grinding roller size.
(2) Adjust wind speed control in different parts
After different materials are ground, the particle size is different, the weight of the particles is different, and the concentration of gas-solid two-phase flow is different. To achieve the transportation of particles with a certain particle size, the vertical grinding chamber needs sufficient wind speed for each part, but it is too high. The wind speed will increase the internal friction and affect the energy consumption of the system fan.
(3) Optimize the structure of the classifier
In view of the high fineness of limestone powder, the matching powder separator optimizes the control of particle motion, limits the irregular motion in the mill, optimizes the distance between the rotor and the guide vane, the rotor speed, the number of moving and static blades, and the geometric size. Powder screening efficiency.