the problem of mill roll oil leakage often appears in the cement mill with vertical grinding, which is always a puzzle for vertical mills. oil spills not only pollute the environment, but also increase production costs.
1、 the existing problems
the problem of mill roll oil leakage often appears in the cement mill with vertical grinding, which is always a puzzle for vertical mills. oil spills not only pollute the environment, but also increase production costs. vertical grinding roller oil many causes, summed up in two main points:
first, grinding roller sealing reasons. the vertical mill grinding roller seal mainly uses 3 skeleton lip seal, 1 dust, 2 oil. but the working environment of the mill is very bad. it belongs to the condition of high dust, high temperature, impact and vibration, so the sealing wear is very fast. and sealing replacement is very difficult, need to roll over, roll the mill from the rocker arm, its work is time-consuming and laborious, the cost of maintenance is very high.
second roller lubrication system, poor oil return. when the roller bearing will generate some heat, and in the high temperature environment, therefore generally uses the circulating oil way, so you can take away excess heat, ensure the normal temperature range in a bearing. but in actual work, if the oil is sluggish, the oil level in the mill will rise and eventually overflow from the oil seal and air.
roller lubrication system leads to poor oil return for the following reasons:
(1) temperature. when the mill is shut down or the ambient temperature is too low, the temperature in the mill roll and the temperature of the oil return pipeline are not high. because the vertical mill generally adopts lubricating oil of about 320mm2/s in viscosity, the fluidity is poor, so the oil back is not smooth.
(2) causes resistance. lubricating mill generally adopts centralized lubrication way, including other oil roller lubrication station, station are placed in a room, from the mill lubrication points are generally far, so the larger pipe resistance, resulting in poor oil return.
(3) pipeline intake causes. in fact, the oil supply and the amount of oil return is not possible to achieve the same, so in order to ensure that the oil level is not too high, the amount of return oil is greater than the amount of oil. back in the lowest level at the need to ensure that the oil, when the oil level is lower than the minimum level when the pump will pump suction air, resulting in reduced ability, poor oil return.
2、 solution
for grinding roller and grinding roller sealing lubrication system is difficult to effectively improve the situation of jidong (321.33 yuan / ton, 0%) equipment from the control level of the grinding roller, a high temperature liquid level sensor increases in the grinding roller, see figure 1. a good result has been achieved.
install the leads from the roller shaft in the roller shaft bearing cover on the liquid level sensor wire, and in oil station oil pipeline adds a three way electromagnetic valve, a normally open point connected with the grinding roller oil pipeline, normally closed connected with the oil return pipe. when measured in the mill level is higher than the upper limit, the electromagnetic valve will put oil pump oil to the oil return pipe, reach the level limit, the electromagnetic valve will be converted into the oil pipeline, so as to realize the control of the oil level of the grinding
roller. as the roller rotates and rolls up and down, the liquid level changes back and forth. when we select the value, we only collect the minimum value in the liquid level sensor 5s as the actual liquid level, so that we can reflect the true situation of the liquid level.
by increasing the liquid level sensor, can ensure the seal wear and poor oil return roller when the grinding roller is not leaking; also can monitor in real time to change the grinding roller of liquid level in the oil level, achieve the purpose of control, and the control of vertical mill and intelligent direction to step forward.
