First, the operation of the transmission system should be flexible, and there should be no abnormal noise; second, the transmission of belt conveyors, bucket elevators and cantilever draglines should be stable, the operation should be flexible, the braking can be high, no abnormal noise, and no jamming. chain; third, the metering system should be sensitive and accurate; fourth, the lifting temperature of the reducer should meet the requirements in the manual; fifth, the metering hopper should be smooth in and out, without accumulation or overflow; sixth, the safety valve should not Air leakage occurs.