The granulation unit is highly integrated with electrical and instrumentation systems, and has a relatively high level of automation control. Therefore, there are many diagnostic faults in actual operation, which result in long processing times and affect the normal operation of the polypropylene unit, greatly reducing the economic benefits of production. Here, based on theoretical knowledge of granulation production process and more than years of practical production and operation management experience, we have analyzed and judged the common causes of faults that occur during the operation of this mechanical combination, and formulated corresponding understanding.

Reason for malfunction:

In the granulation group, there are four main reasons for the detachment of the friction gift box device and the chain shutdown of the unit during the operation of the instant group.

Main motor system faults: manifested as high or low torque of the main motor; The main motor speed is too low; The temperature of the main motor bearings is too high; The temperature of the main motor winding is too high; The temperature at the outlet of the water-cooled cooler of the main motor is too high; The outlet flow of the lubricating oil pump for the main motor bearing is too low; The outlet pressure of the lubricating oil pump for the main motor bearing is too low; The main motor's water-cooled cooler has a high leakage rate.

Rotating system malfunction: mainly manifested in the deviation of the gearbox gear lever position; The instrument air pressure of the grinder clutch is too high; The speed difference of the friction clutch is too large; The outlet pressure of the gearbox lubricating oil pump is too low; The gearbox lubricating oil pump and oil removal pump are too high; Internal faults of friction clutch, etc.

Granulator Building Xi'an Steel Process Fault: The main surface is that the melt pressure before and after the throttle valve is too high; The melt pressure of the machine head is too high; The pressure difference between the melt before and after the screen changer is too large; Driving valve rotation failure, etc.

Underwater granulation system malfunction: The temperature of the granulation electrode winding is too high; The speed of the granulator is too low, and the torque of the granulator is too high; Automatic switching failure of granular water bypass; Particle water pressure is too high or too low; The particle water flow rate is too low, and the clamping bolts of the granulator are not tightened properly; The bypass water valve of the cutting chamber is not closed; The hydraulic clamping of the granulator is too low; Particle cutting motor malfunction; The axial feed pressure of the hydraulic cutter is too low, etc.