How to reduce compressor vibration problems?
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The 6M50 compressor pipelines in my company have serious vibrations, especially the three-outlet and four-outlet pipelines. Can I use a fixed bracket to fix them? If a fixed bracket is used to fix the pipeline, will it have any impact on the compressor inlet and outlet buffer tank? It turned out that the second buffer tank had cracked the tank weld due to pipe vibration.
It is recommended not to weld and fix: If the fixed spot welding is not strong enough, it will vibrate. ； If the welding is too strong, other joints of the pipe will be shaken open, which is even worse. You can add a shock-absorbing flange nipple to the pipe connection or replace a section of reinforced metal hose, and regularly check the reliability of the hose.
The short-term solution is to add pipe supports and forcibly fix the pipes and buffer tanks. If the buffer tank stops vibrating or the vibration is small, the welds will not crack. :lol The best and long-term solution is: Conduct stress analysis on pipes with large vibrations to see if there is resonance and modify the pipes during overhaul.
Here are some measures for reference: ①Calculate the mechanical natural frequency of the piping system so that the mechanical natural frequency is offset from the piston excitation frequency and offset from the gas column natural frequency. ②On the premise of satisfying the pipeline flexibility analysis, turns should be minimized to reduce the vibration caused by the exciting force at the elbow. ③The bracket should be an anti-vibration pipe frame, not just a load-bearing or thrust frame. ④The spacing between brackets should meet the minimum frequency requirements. ⑤Pipes should be laid along the ground as much as possible. If the pipe is too high, it will be difficult for the bracket to take root. At the same time, it is difficult to ensure the stiffness of the bracket. ⑥In order to prevent the unbalanced rotation force of the unit from causing vibration in the piping system, the inlet and outlet buffer tanks must have firm supports. ； ⑦Brackets should be added at places where mass is concentrated, such as valves, to increase the rigidity of the pipeline.
This is a common problem with most piston compressors. Solution: Increase the density of fixed brackets, and the fixed bracket foundation should be connected to a large foundation to increase its stability. It is best to contact a scientific research institution (Xi'an Jiaotong University has a pipeline vibration research laboratory) or a compressor manufacturer to find a fundamental solution.
According to experience, the compressor outlet pipeline has undergone pulsation analysis by the manufacturer, that is, when designing the piping, the piping layout and plane must be provided to the manufacturer for calculation. Therefore, if the pipeline vibrates, you cannot blindly add pipeline fixing brackets. Design drawings should be provided to the compressor manufacturer for pulsation and stress recalculation. In addition, check whether there are any problems with the construction quality. For example, if the installation stress of the pipe mouth is too great, has it been inspected for stress-free during installation? In addition, the problem of vibration of the unit is not mentioned. The foundation should not participate in the resonance. Otherwise, the foundation will also need to be modified, which is troublesome. This really requires the design to be held accountable!
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