Wear on the high-pressure side of the second stage head of the oil-free twin-screw compressor
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What causes wear on the high-pressure side of the second stage of an oil-free twin-screw compressor, wear on the end face of the rotor against the end face of the casing, and melting on the surface of the male rotor (with process gas as the medium)?
It may be caused by the following reasons: 1. The load on the high-voltage side of the motor during operation is too large, resulting in increased wear； 2. Poor bearing lubrication or insufficient lubricant leads to increased wear ； 3. Hard particles or debris present in the medium, leading to increased wear ； 4. The excessive surface temperature of the rotor may be due to overload or improper control by the frequency converter ； 5. Defects in the design or manufacturing process of the nozzle lead to increased wear on the high-pressure side of the nozzle. .
There is no issue with the lubricating oil or the medium; the problem occurred during the trial operation phase. The equipment is equipped with interlock controls, and during testing, loud noises were heard on site, which led to the immediate shutdown of the equipment. I think there is a problem with the design of the axial force balance within the machine or rotor; wear on the high-pressure side at the exhaust end causes the rotor to shift from the low-pressure side to the high-pressure side. There are balance pipes between the high-pressure and low-pressure sides, and issues with the balance piston or other components on the high-pressure side lead to an excessive pressure difference between these two sides. The normal pressure at the secondary inlet is around 0.6 MPa.
Based on your description, the wear may be caused by a design issue related to the internal axial force balance of the machine body or rotor. Since the noise was detected immediately during the trial run phase and the equipment was shut down, it was possible to further tune the equipment before inspecting and repairing the damage to the head, in order to determine which components were damaged and identify the root cause of the internal axial force imbalance. For any faults that may exist in the balance piston on the high-pressure side or other related components, they can be carefully inspected and the damaged parts replaced. After the repair, a thorough inspection and testing are required to ensure that the problem has been resolved and that the pressure at the secondary inlet is within the normal range. .
How long has it been running? Is the exhaust temperature usually high? What is the gap between the male and female rotors?
End-face wear during startup may be caused by improper axial adjustment, and it usually occurs during trial runs after maintenance.
During the trial operation, in less than 3 minutes, the parameters of the foreign-made units were kept confidential and not disclosed; even the domestic manufacturing plants were unaware of them
It has only been in trial operation for less than 3 minutes; logically speaking, it’s likely that there is a problem with the exhaust clearance of the rotor