The reasons and solutions of oversize particles in vertical roller mill

Vertical roller mill is a frequently used pulverizing equipment, so in the actual production process, it may be due to improper operation, resulting in excessive discharge particles of vertical roller mill, then, what are the causes and solutions of excessive particles?

 

1. Improper speed adjustment of powder concentrator

Adjusting the rotor speed of powder concentrator is a common method to adjust the fineness, and it is also an important method. Usually change the fineness: the first thought is to adjust its speed, when the particle is too large, increase the speed.

 

2. Too much ventilation

In the trial production, when the hot blast furnace or less feeding is used, the internal ventilation of the roller mill is small, the speed of the powder concentrator is set at 70-80%, and the fineness can be basically achieved. With the increase of hot air at the kiln tail, the increase of ventilation in the vertical roller mill, the increase of EP fan baffle, the fineness will rise, at this time, the speed of the powder concentrator should be increased gradually to ensure the fineness is qualified.

 

3. Low grinding pressure

The pressure of the vertical roller mill can be set in the central control. Generally, the pressure is set to be small when the roller mill is opened. With the increase of the output, the pressure must be gradually increased, otherwise the particle size will be too large due to the insufficient capacity of crushing and grinding.

 

4. Temperature effect

The outlet temperature of the vertical roller mill rises rapidly or maintains a high temperature, and the size of the material out of the roller mill may be too large, because in the process of temperature rise, the speed of the fluid in the vertical roller mill and the internal energy of the material in the roller mill are changed, and the material with large brown motion of the fine material is pulled out of the roller mill. This may be caused by the change of air temperature and air volume at the kiln tail or the change of moisture content of materials entering the vertical roller mill. At this time, the water spray in the grinding mill can be adjusted to solve the problem. The process line in series between the roller mill and the humidification tower can adjust the water spray of the humidification tower, and can be mixed with circulating air or cold air when the air volume allows.

 

It is easy to make the working condition in the vertical roller mill disordered, the wind speed and air volume fluctuate, and the discontinuous particles are too large. Solution: stabilize the amount of grinding materials, ensure the right amount of grinding pressure, or reduce the output.

 

5. Poor grindability of grinding materials

The strength and hardness of the material entering the vertical roller mill is large, or the particle diameter of the material is large, so it is difficult to break and grind. In addition, the number of times of stopping grinding cycle is increased, which finally shows that there are too many materials in the vertical roller mill.

 

As a professional manufacturer of grinding mills, Shuguang Heavy Machinery sells a variety of different types of mill equipment, including ball mills, Raymond mills, vertical mills, etc.Welcome to contact us for more details.

 

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