CHAENG takes the GRM vertical roller mill as an example to analyze the reasons for the fracture of the vertical mill roller shell:

1.Material and heat treatment

The wear of the roller shell is high-stress wear and requires high hardness. The higher the hardness, the more carbides contained in the steel castings are required, and the more dispersed the distribution, the greater the probability of forming micro-holes and micro-cracks at the interface between the matrix and the carbides, and the greater the probability of fracture.

Heat treatment is very important to the hardness and quality of the product. It can be seen that the material and heat treatment are the root causes of the fracture of the vertical grinding roller sleeve.

2.Equipment use and maintenance 

The use and maintenance of vertical mills are demanding. Reasonable and reliable equipment use and maintenance are the key to preventing and reducing the fracture of vertical mill roller shell.

3.Machining error of mating surface

Less mating surface machining error is the prerequisite to prevent and reduce the fracture of the vertical mill roller shell.

CHAENG puts forward the following four preventive measures according to the cause of the fracture of the vertical mill roller shell:

1) Use special materials for casting to control the roller shell hardness, and do not emphasize the hardness one-sidedly.

2) Strictly control the proportion and particle size of the materials entering the mill, prevent the entry of bulk materials, and try to avoid the strong vibration in the production of the vertical mill.

3) When starting and stopping the vertical mill, strictly control the heating and cooling time and speed in accordance with the technical specifications.

4) The mating surface of the roller shell and the hub ensures the machining accuracy.

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