During the operation of the vertical roller mill, some unexpected problems always occur. These problems are also within the scope of normal problems, and can be completely avoided by some measures. The following is an analysis of common problems and solutions for operating vertical roller mills!
(1) The feeding is not uniform. When the mixture into the mill is mostly powder, the load rate in the mill is large, resulting in a thin material layer on the grinding disc, and even the grinding disc directly contacts the grinding roller, causing vibration grinding. When the mixture is mostly block materials, the pressure difference of the grinding roller is unstable, and vibration grinding occurs. The solution is to stabilize the granularity of the materials to be ground, appropriately adjust the feeding speed or reduce the grinding pressure, and properly reduce the speed of the powder separator under the premise of ensuring the fineness of the materials.
(2) Metal parts enter the mill, check whether the metal detector and the magnet separator work normally.
(3) The kiln exhaust fan is damaged due to vibration or the kiln tail exhaust pressure is high, unstable, and the dust concentration is too high, which increases the internal load of the mill. Increasing the circulation damper into the mill increases the negative pressure of the population of the mill and balances the mill's operation.
The possible reasons are:
(1) Low feed rate;
(2) the product fineness is too fine;
(3) System air volume is low.
The solution is to increase the feed rate or increase the grinding pressure, reduce the speed of the powder separator, and increase the system exhaust. Conversely, when the production capacity of the mill is too high, the solution is the opposite.
When the feeding and storage materials are found to be insufficient, the machine should be stopped. At this time, if there is a risk of empty grinding when continuing to transport the materials, the materials should be fed to the feeding device and the mill. Otherwise, the material bed will become thin and a rumbling sound will occur, causing the reducer damage.
At this time, reduce the supply immediately and observe the pressure difference indicating device. Check its possible causes:
(1) The feeding device is faulty and the feeding is too much;
(2) The nozzle ring of the grinding disc is blocked;
(3) The air volume is too low or unstable;
(4) The fineness of the powder separator adjustment is too fine.
Reason for too small differential pressure:
(1) The feeding rate is too low to interrupt the feeding;
(2) The fineness of the product is too coarse.
The tension drop of the system should be checked:
(1) Whether the conduit is leaking;
(2) Whether the pressure relief valve fails;
(3) Whether the oil pump works normally;
(4) Whether the pressure switch is a bnormal
These problems are common and caused by incorrect operation methods of the operators, so it is necessary to strengthen the training of the operation of the vertical roller mill, and it is also very beneficial to the enterprise itself.