High pressure grinding roller inspection and maintenance

High-pressure grinding rolls is mainly used in the ore industry and is also a type of crusher. As the main equipment for crushing in the ore industry, since it is the main equipment, it will be used very frequently. All machines are inseparable from daily maintenance and overhaul. Correct maintenance and overhaul can increase the service life of the machine, and early overhaul can detect problems early, so that small problems will not become bigger, affecting normal work and causing accidents.

Common fault inspection and repair of high-pressure grinding rolls

1. If the lubrication system finds that there is no grease overflow from the labyrinth seal of the bearing seat, the following reasons may be the case: 

① lack of oil; 

② pipeline failure; 

③ grease pump is broken. If the color and properties of the oil flowing out of the oil drain port of the non-loaded bearing seat are found to have changed, it may be that cooling water or other foreign matter has been mixed into the lubricating grease.

2. The movable roller moves irregularly in the horizontal direction. Generally, the nitrogen accumulator pressure is insufficient or damaged.

3. The hydraulic oil temperature is high. It may be: serious internal leakage in the system or the pump has been running for too long, and the hydraulic system needs to be checked.

4. The roller gap is too large. There may be the following reasons: 

① Severe wear on the roller surface; 

② No pressure; 

③ There is material accumulation between the rollers. It needs to be handled as appropriate.

5. The roller gap is too small. It may be that there is a problem with the size of the gap block, or the position of the displacement sensor is set incorrectly.

6. The roller is stuck. It may be that there is foreign matter between the rollers, or there is too much material stored between the rollers when starting.

7. The roller does not rotate. The reasons include: 

① Motor failure; 

② Reducer failure.

8. The roller surface temperature is too high. It may be that the feed temperature is too high. Measures should be taken to control the upstream raw material temperature, otherwise it will affect the wear resistance of the roller surface and accelerate wear.

9. The bearing temperature is too high. The reasons include: 

① Problems with the water cooling circulation system; 

② Insufficient grease supply;

③ Wrong grease number or fake.

Maintenance of high-pressure grinding rolls

1. It is necessary to ensure that the straight hopper on the high-pressure grinding rolls has a high enough material column so that the two rollers are always buried under the material. If this cannot be guaranteed, many adverse consequences will occur. First, insufficient feed will prevent the hydraulic cylinder from generating enough pressure to roll the material, resulting in the material performance not being improved after the roller mill, which is just a waste of electricity and equipment; secondly, since the material column cannot be formed, the material falls directly from the belt and washes the roller surface, which will greatly accelerate the wear of the roller surface; at the same time, due to uneven feed, it is easy to cause the moving roller to deviate and damage the roller bearing seat.

In addition, insufficient feed, sometimes more and sometimes less, will also cause the hydraulic system to start frequently and shorten the life of the hydraulic components. Therefore, when the system is started, in order to form a material column as soon as possible, the buffer feed belt can be opened faster, and the feed amount can be increased in a short time. After the material column is formed, it can be restored to the specified feed amount.

2. In case of an emergency, the machine should be stopped immediately and the upstream belt should be turned off. Otherwise, within a few seconds, the material will fill the hopper and block the belt discharge port, causing the belt to burn due to friction in a short time. Similarly, if the discharge belt stops during operation, serious consequences will occur. Therefore, the high-pressure grinding rolls should be controlled in linkage with the upstream and downstream belts.

3. Since the role of the high-pressure grinding rolls is very important and the structure is complex, a detailed operation and maintenance ledger should be established to record the operation and maintenance status of the equipment every day, including: cumulative operation time; temperature, pressure, flow, current and other data of each detection point; description of abnormal phenomena; time, content, results and maintenance person in charge of fault handling; time and time interval for lubricating grease replacement, etc.

4. The quality of lubricating grease must be strictly controlled to fully meet the requirements of the equipment. For example, grease distributors are mostly imported accessories, which are very precise and have a long life under normal use conditions. However, many domestic manufacturers often replace the distributor because impurities are mixed in the grease, blocking the valve parts in the distributor and causing jamming. At the same time, since the accessories are relatively precise, they are not easy to repair and have to be replaced, which causes great waste.

5. Bearing temperature changes and the flow of circulating cooling water pipelines should be checked regularly to ensure that circulating cooling water is evenly distributed to each cooling position.

6. Adequate supply of grease and hydraulic oil should be ensured. Spare grease should be placed near the hydraulic station. Once used up, it should be replaced in time to ensure the continuity of production.

7. The surface wear of the secondary roller should be checked regularly every month. The surface measurement data during roller installation and commissioning should be compared to determine the roller condition, wear rate, replacement time or repair measures.

8. It is strictly forbidden to enter the equipment with iron blocks, debris, etc. The mixing of debris in the iron material will not only affect the hydraulic system, but also seriously damage the roller surface, directly affecting the roller pressing result.

9. When the equipment is debugged or after the oil is changed again, the exhaust holes on the hydraulic cylinder and the valve seat in the hydraulic system should be opened one by one to exhaust the air in the hydraulic system.

10. Before each start, the straight hopper should be emptied in advance to avoid pressure fluctuations in the hydraulic system and overload of the equipment.

11. The gap size of the roller side sealing plate should be checked and adjusted regularly to prevent the material from flowing down and affecting the roller pressing effect.

After reading the article, do you have a certain understanding of the inspection and maintenance of high-pressure roller grinding mill? Luoyang Zhongyuan Mining Machinery Manufacturing Co., Ltd. reminds you: In order to increase the service life of the machine and improve the machine's operating efficiency, daily inspection and maintenance are essential.