No-load testing involves running the mill without media (balls, rods) or material. Continuous operation should not be less than 4 hours, generally 8-16 hours, depending on the specific circumstances. The longer the test time, the better the meshing of the main bearings and gear teeth. The no-load test should meet the following requirements:
(1) Lubrication at all lubrication points is normal, with no oil leakage.
(2) The temperature of the grinding mill’s main bearing should not exceed 50℃.
(3) The grinding mill runs smoothly, with no abnormal noise in the gear transmission.
(4) There is no looseness in the liners and transmission components.
(5) The operation of all parts meets maintenance requirements.
After the specified no-load time, stop the grinding mill, carefully inspect all working parts, tighten the liner bolts, and eliminate any defects found.
Only after passing the no-load test can the load test be conducted. During the load test, gradually add material until full load, and run for 10-20 hours after normal feeding. Under load, the following requirements should be met:
(1) Smooth operation without periodic or sudden vibrations.
(2) No abnormal fluctuations in the main motor current.
(3) Normal lubrication at all lubrication points, with the main bearing temperature not exceeding 60℃.
(4) No leakage of water or slurry at bolts, manholes, flange mating surfaces, or seals in any working part of the grinding mill.