Solution to Oil leakage of Vertical Mill RollerDate: 2019-06-21 Views:
1. Existing problems
The oil leakage problem of grinding roller often occurs in cement plants with vertical mill, which is always a difficult problem for vertical mill manufacturers. The oil spill not only pollutes the environment, but also increases the cost of production. There are many causes of oil leakage in vertical grinding roller, which can be summarized as follows:
First, grinding roller seal reasons. At present, the vertical grinding roller seal mainly adopts 3 skeleton lip seal, 1 dust proof and 2 oil proof. However, the working environment of vertical mill is very bad, which belongs to the working condition of high dust, high temperature and impact vibration, so the seal wear is fast. And the seal replacement is very difficult, need to roll over, remove the roller from the rocker arm, its working time, laborious, maintenance cost is very high.
Second, the roller lubrication system oil return is not smooth. When the roller is working, the bearing will produce some heat, and it will be in the high temperature environment, so it usually adopts the way of dilute oil circulation lubrication, which can take away the excess heat and ensure that the bearing is in the normal temperature range. But in practice, if the return oil is not smooth, the oil level in the roller will rise, and finally overflow from the oil seal and air.
The reason that the oil return of the grinding roller lubrication system is not smooth is as follows:
(1) the cause of temperature. When the grinding or ambient temperature is too low after shutdown, the temperature in the roller and the temperature of the oil return pipeline are not high. Because the vertical mill generally uses lubricating oil with viscosity of about 320mm2/s, the liquidity is poor, so the return oil is not smooth.
(2) The reason for resistance. The lubrication of the vertical mill generally adopts a centralized lubrication mode, and other oil stations, including the roller lubrication station, are concentrated in a room, and the distance of the vertical mill lubricating points is generally far from that of the vertical mill, so that the resistance of the pipeline is large, and the oil return is not smooth.
(3) The reason for pipeline air intake. Since the amount of oil supply and the amount of oil return are not possible to be consistent, in order to ensure that the oil level is not too high, the amount of oil return is greater than the amount of oil supply. The return oil is set at the minimum oil level to be ensured. When the oil level is lower than the minimum oil level, the oil return pump will be sucked and empty, and the oil return pump capacity is reduced and the oil return is not smooth.
Therefore, under the condition that the roller sealing and roller lubrication system is difficult to be effectively improved, a high temperature resistant liquid level sensor is added to the roller by controlling the oil level in the roller, the liquid level sensor lead installed on the roller bearing cover is drawn from the roller shaft, and a three-way solenoid ball valve is added on the oil supply pipe of the petrol station, which is connected with the roller oil supply pipeline and connected with the return oil pipeline. When the inner grinding liquid level is measured to be higher than the upper limit, the solenoid ball valve will transfer the oil supplied from the oil pump to the return pipeline, and when the lower limit of the liquid level is reached, the solenoid ball valve will be converted to the oil supply line, thus realizing the lubricating oil level in the roller. Control. Because the roller rotates and fluctuates up and down, and the liquid level changes back and forth, when the value is taken, we only collect the minimum value in the liquid level sensor 5s as the actual liquid level value, which can reflect the real situation of the liquid level.
By adding liquid level sensor, the grinding roll can not leak oil when the roller seal is worn and the return oil is not smooth, and the change of liquid level in the roller can also be monitored in real time, so that the oil level can be known and controllable, so that the control of vertical mill has taken a step forward in the direction of intelligence.