Material Bluestone Of Vertical Mill Appears To Run Coarse

Summary

Vertical mills are often used to process bluestone, limestone, calcite and other materials. Some minor problems will inevitably occur during operation. Generally, the discharge granularity of the vertical mill will set the corresponding fineness mesh value, such as 325 mesh, but sometimes the actual

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Detailed Introduction

Vertical mills are often used to process bluestone, limestone, calcite and other materials. Some minor problems will inevitably occur during operation. Generally, the discharge granularity of the vertical mill will set the corresponding fineness mesh value, such as 325 mesh, but sometimes the actual output granularity will be coarser, only reaching 260 mesh. This phenomenon of running coarse powder will affect the quality of finished products. Still needs to be rebuilt.

1. Improper speed adjustment of powder selection device

Adjusting the rotor speed of the powder selection device is a common method of fineness adjustment, and it is also an important method. Usually change the fineness: the first thing that comes to mind is to adjust its speed, and increase the speed when running rough.

2. Excessive ventilation

In trial production, when using a hot blast stove or less input, the internal ventilation of the mill is small, and the speed of the powder separator is set to 70-80%, and the fineness can basically be achieved. With the increase of the hot air at the end of the kiln, the ventilation in the mill increases, the fan baffle increases, and the fineness will increase. At this time, the speed of the powder separator should be gradually increased to ensure that the fineness is qualified.

For example: when the kiln feed is at full load, the kiln tail air volume is very large, even when the fan is turned on to 100%, the mill inlet still has positive pressure. At this time, the fineness is easy to increase. Even if the powder separator is added to the limit, the fineness cannot pass . At this time, you can consider turning on the bypass baffle, but this method is more dangerous and easily causes the mill to stop. Therefore, care must be taken. Every 1% of opening has to be observed for a long time to ensure the smooth operation of the mill. The fineness can be reduced within a certain range. This method is used when the air volume is too large.

3.Low grinding pressure

The pressure of the LM series vertical mill can be given in the middle control. Generally, the pressure is set to be small when the mill is started. As the output increases, the pressure must be gradually increased. Coarse phenomenon.

4.Temperature effect

The mill outlet temperature rises rapidly, or maintains a high temperature, and the milled material may run coarse, because during the temperature rise, the fluid speed in the mill and the internal energy of the mill material are changed, and the fine material does Brownian motion. Larger materials are pulled out of the mill. This may be caused by the kiln tail air temperature, air volume change or the moisture content of the milled material. At this time, the water spray in the mill can be adjusted to solve it. The process line of the 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.

The instability of entering the mill easily makes the working conditions in the mill chaotic, and the wind speed and volume fluctuate, causing intermittent rough running. Solution: Stabilize the amount of material to be ground, ensure the right amount of grinding pressure, or reduce the amount of output.

5. Poor grindability of grinding materials

The strength and hardness of the materials to be ground are large, or the diameter of the material particles is large, and it is difficult to break and grind. In addition, the number of grinding stop cycles is increased, and the final performance is that there are too many materials in the grinding.

6. equipment wear and tear

After the mill has been running for a long time, the blades of the powder selection device, the rollers, the lining of the grinding disc, and the nozzle ring will be subject to different degrees of wear, which can cause the fineness of the mill to run coarse.

Powder selection device, nozzle ring, etc. should pay attention to maintenance at ordinary times, and should be replaced and repaired in time if the damage is serious.

7. Rough running due to equipment failure

The powder separator is damaged and the material runs coarse. During a period of time when the powder separator cannot be recovered, the operator controls the pressure, air volume and temperature to reduce the fineness by about 21%, which can basically be used for calcination in the kiln.

Usually fineness running is not caused by a certain reason. Similarly, reducing the fineness is not just a method. You can find the main reason for running coarseness. For this reason, take a method and use other methods to make up for this method. Insufficient to achieve the purpose of reducing fineness.

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