Answer 1: Under normal circumstances, the causes of high vibration of vertical mill are as follows: 1) Vibration caused by impact load caused by foreign matter entering the mill; 2) The material layer thickness is too high to cause the material layer to hold up the grinding roller too high to cause vibration; 3) The thickness of the material layer is too low, resulting in vibration caused by the contact between the grinding roller and the grinding disc; 4) Unreasonable structure of feeding device, system blockage, induce large vibration; 5) The system air volume is too large, less material and vibration, the system air volume is too small, more material and vibration; 6) The grinding particle size is too large, the centrifugal effect is obvious, the shape of the material layer is high outside and shallow inside, the external circulation increases, and the vibration is large; 7) If the grinding particle size is too small, the grinding material is suspended in the mill, the grinding plate material is less, and the vibration is large.

Answer 2: 1, the speed of the powder selection device is not adjusted properly Adjusting the rotor speed of powder selecting device is the most common method to adjust fineness, but also one of the most important methods. Usually change fineness: the first thought is to adjust its speed, when running thick increase speed. 2. The ventilation volume is too large In the trial production, when the hot blast stove or feeding is less, the internal ventilation of the mill is small, and the speed of the powder separator is set at 70-80%, the fineness can be basically achieved. With the increase of hot air at the end of the kiln, the increase of ventilation in the mill and the increase of EP fan baffle plate, the fineness will rise. At this time, the speed of the powder separator should be gradually increased to ensure that the fineness is qualified. 3, small grinding pressure Vertical mill pressure can be given in the central control, generally the pressure is set to the minimum when grinding, with the increase of output, must be gradually pressurized, otherwise because of the crushing and grinding capacity is insufficient, and the phenomenon of running. 4. Temperature effect When the exit temperature of the mill rises rapidly or maintains a high temperature, the material may run coarse, because in the process of temperature rise, the fluid velocity and the internal energy of the material in the mill are changed, and the larger material will be pulled out of the mill when the fine material does Brownian motion. This may be caused by the change of wind temperature and air volume at the end of kiln or the change of moisture content of grinding materials. The process line in series between the mill and the humidifier tower can adjust the water spraying of the humidifier tower, and can be mixed with circulating air or cold air if the air volume allows. 5. Poor grindability of grinding materials The strength and hardness of the material entering the mill are large, or the diameter of the material particle is large, which makes it difficult to break and grind. In addition, the number of grinding stop cycles increases, and the final performance is too much material in the mill. Solution: A. Improve the grindability and diameter of grinding materials; B. Appropriate amount; C. Reduce the yield appropriately. 6, the equipment wear seriously After the mill runs for a long time, the blades of powder selecting device, roller skin, disc lining plate and nozzle ring will be worn to varying degrees, which may lead to coarse fineness of the mill. Powder selection device, nozzle ring and other usually should pay attention to maintenance, serious damage to be replaced in time, repair. 7, equipment failure and run rough The powder selecting machine is broken, and the material is running thick. During a period of time when the powder selecting device cannot be restored, the operator uses control pressure, air volume and temperature to reduce its fineness to about 21%, which can be basically used for calcination of kiln.