Vertical mill working principle:
The material discharge pipe falls to the center of the vertical mill grinding table, and the grinding table rotates at a constant speed to uniformly disperse and flatten the raw material outward by the action of centrifugal force, so that a material bed of a certain thickness is formed, and the material is simultaneously crushed by a plurality of grinding rollers on the grinding table. Pressed and crushed. Under the continuous driving of centrifugal force, the material continuously moves to the outer edge of the grinding table, and the material leaving the grinding table encounters the hot gas entering the grinding sand through the air ring and rises accordingly, and enters the separator through the middle casing of the mill, in the process. The material is fully exchanged with hot gases and the water is quickly evaporated. The classifier controls the fineness of the finished product at the roller mill outlet. Particles larger than the specified size are separated and fall back to the grinding table. The material that meets the fineness requirements enters the finished product bin through the sorting machine.
According to the working principle of the VRM, the vertical mill needs a series of preparations before it is officially started.

The operator should confirm the following aspects before starting:
1. The lubrication system and hydraulic system of the vertical grinding main reducer should be suitable. The oil level should be between the upper and lower oil marks. There should be no oil leakage at each joint of the oil pipeline, the instrument is intact, the pipeline and the garden gate are unblocked, and the oil temperature is suitable. Check that all other lubrication systems have the right amount of oil, including all bearing lubrication and lubrication of the reducer and electric valve.
2. The inside of the equipment, the manhole door and the inspection door must be strictly sealed to prevent all the manual gate valves in the air leakage, leakage and oil leakage system from being opened to the proper position during production to ensure smooth flow of materials and gas. All electric gates should be checked for flexibility in opening and closing, and whether the valve shaft and connecting rod are loose. For the remote control valve of the central control room, it is necessary to confirm that the central control room is in the same direction as the opening and closing of the site. The opening degree and indication are accurate, with upper and lower limits. The valve of the position switch needs to check whether the limit signal is returned with the central control room.
3. Check the fasteners of the equipment (such as the bolts of the classifier, the base bolts of all the equipment, there must be no looseness. Strictly check the loose parts such as the equipment transmission.
4. All parts that need to be covered should be covered, such as the safety inspection cover of the equipment, the cover of the screw conveyor, the cover of the trench, etc., should be checked one by one.
5. Before starting the equipment, check whether the water supply and drainage pipeline valve is open, and the water connection part should be guaranteed to have no leakage. Pay special attention to the cooling water of the cooling and lubrication hydraulic unit, and must not flow into the oil. Reasonable control of the amount of cooling water. Confirm the range of the thickness of the layer on the vertical grinding disc.
6. Verify that the nitrogen pressure in the vertical mill accumulator meets the start-up conditions.
7. Confirm that all equipment has a ready signal and meets the start-up conditions.
8. On-site temperature, pressure and material level gauges, before starting the vehicle, check the system and confirm that the power supply is available. Each valve opening indication shall be consistent with the on-site, central control indication and the mechanical device's own position, and the operation is flexible.