How to determine if a sand mill needs maintenance?

I. Abnormal operating status signals
1. Abnormal temperature
Grinding chamber temperature continuously exceeds the set value (usually >60°C) and the cooling system is ineffective
Bearing temperature rises abnormally (noticeably hot to the touch)
2. Pressure fluctuation
Grinding chamber pressure frequently triggers protection thresholds (exceeds the set detection value)
Unstable seal pressure leading to material leakage
3. Noise and vibration
Metal friction sounds or periodic abnormal noises are heard during operation
Increased vibration amplitude (can be tested with a vibration meter; be cautious if amplitude >0.5mm)
II. Regular inspection results
1. Sealing system
Seal ring cracks, deformation, or leakage >5 drops/minute
Seal grease is dry or contaminated
2. Grinding media Media wear rate > 30% (requires sieving and weighing)
Media agglomeration or uneven particle size distribution
3. Lubrication system
Bearing grease discoloration (black or containing metallic particles)
Lubrication interval exceeds 400 hours without refilling
III. Decreased production efficiency
1. Reduced grinding efficiency
Production capacity decreases > 15% under the same process conditions
Material fineness fails to meet process requirements
2. Abnormal energy consumption
Motor current fluctuation exceeds 10% of the rated value
IV. Maintenance cycle triggering
1. Time period
Failure to perform spindle cleaning after 2000 hours of continuous operation
Failure to replace grinding media for more than 6 months
2. Environmental factors
Failure to perform rust prevention after use in a high-humidity environment
Failure to complete antifreeze protection before winter shutdown