The reason why the output of vertical mill becomes low
Date：2019-07-03 15:34 Source：未知Views:
1. Wear of roller and disc liner
In the vertical grinding operation, the grinding pressure is applied by the grinding roller, and the material is subjected to the pressing and shearing force between the grinding roller and the grinding plate to achieve the purpose of grinding the material, so the abrasion of the grinding roller surface and the lining plate of the grinding plate is inevitable. With the extension of grinding time, the wear of lining plate will be more serious, and the clearance between the grinding roller and the grinding plate becomes large or uneven shape, and the grinding efficiency will be greatly reduced, resulting in a great decrease in vertical mill output.
In this case, the wear of the lining plate shall be checked regularly, and when the grinding roller and the millstone lining plate are worn to a certain extent, it must be replaced in time so as not to affect the vertical grinding operation due to the large vibration or other problems caused by the abrasion of the lining board. The lining plate wear shall be checked and processed in time, and the service life of the lining plate can be prolonged by changing the surface of the lining plate and appropriately lowering the height of the stop ring.
Grinding plate lining
2. Wear of the stop ring
The effect of the stop ring is to enable the material to be fully ground on the grinding disc. the material blocking ring is subjected to wear or fall, so that the thickness of the material layer is reduced, the vibration of the grinding machine is increased, the coarse powder is not fully ground, the grinding disc is thrown out under the action of the centrifugal force under the action of the centrifugal force, the return amount is increased, the total grinding amount is increased, the vertical grinding yield can be reduced, and the vibration is large, It is also easy to jump and stop, affecting the operation of the mill. Therefore, check the stop ring regularly and timely handle the problems.
Material retaining ring
3. Wear of nozzle ring
The main function of the nozzle ring is to change the wind direction through the guide vane, so as to ensure that the air flow is rotating upward, and the material is taken away. If the nozzle ring is worn or locally subjected to wear, the air flow is changed, the stable rotary ascending air flow can not be formed, and the wind speed is also reduced, and the material can not be taken away in time, and the material can not be taken away in time, and the material cannot be returned to the grinding disc or the bottom scraping cavity of the falling person nozzle ring, and the circulation amount is increased to influence the mill output.
4. Performance of the incoming and grinding materials
1. The hardness of the incoming grinding material is large, such as the poor quality of the high silicon material. In order to reach the qualified raw material, it is necessary to extend the powder grinding time of the material, increase the internal circulation, and the material in the mill can not be discharged in time, and only the production operation can be reduced.
2. When the particle size of the grinding material is too large, the grinding frequency is increased, the circulation amount is increased, the pressure difference is high, the grinding is difficult, and the large vibration is also caused, and the operation is not balanced.
5. air leakage of the system
The air leakage of the mill body is bound to cause the pressure difference is small, the wind speed is not enough, the powder can not be taken away in time, which affects the output of the mill. In addition, other parts of the system leakage, wind speed will be reduced, will cause pipeline material accumulation. After the pipe accumulates, the ventilation area will become smaller, and the insufficient air volume will also affect the mill output. Therefore, it is necessary to check and deal with the air leakage in the system in time.
6. Thickness of material layer
After the material is fed into the grinding disk, a certain material layer is formed. when the thickness of the material layer reaches a certain thickness, the grinding roller begins to grind. If the material layer is too thin, the grinding stress is too concentrated, and the grinding ability decreases, it will inevitably lead to the impact of roller liner and disc liner, the vibration of mill is large, it is easy to jump, and it will also damage the liner, tension rod and so on, so it can not be controlled by thin material layer. If the thickness of the material layer is thicker, the grinding force will be transformed into lateral stress, and sliding shear will be formed between the materials, the collapse degree of the material bed will increase, the grinding efficiency will decrease, and the vibration will also be large; the material can not be ground in time and extrude the grinding disk, fall to the nozzle ring, increase the circulation, the pressure difference is large, the material can not Timely grinding, the formation of a vicious circle, can only reduce production operation, affecting mill output.
The thickness of the material layer is generally controlled around 50-80mm. The principle is that the material fed into the mill should be ground in time and flow to the next process in time. The pressure difference of the system should not be controlled too high to ensure that the vibration is within a reasonable range.
In addition to the above factors, there are many factors that affect the output of vertical grinding, such as material segregation caused by mixture structure, air volume control, hot air temperature control, proportioning control and so on, which will affect the output of vertical grinding. In the actual production, it should be analyzed according to the specific situation of our factory, aiming at solving the problem.