Machine data:

  • Manufacturer: Ariel
  • Drive power: 6150 kW (8636 hp)
  • Speed: 700 rpm
  • 6 cylinder
  • Double acting, 2 stages
  • Suction pressure: 40 bar
  • Discharge pressure 240 bar

Sequence of events:

3:45 AM
PROGNOST®-SILver Protection hardware shut down the monitored compressor. Initiated because of piston rod position of cylinder 1.

5:02 AM
PROGNOST®-SILver tripped the compressor again during start-up. Again due to rod position cylinder 1.

9:45 AM
PROGNOST Customer Support recommends to make no restart, cause of high piston rod movement

Screenshots from Online Condition Monitoring system PROGNOST®-NT:

  • 2 months 3D-trend of rod position

  • 2 months 3D-trend of crosshead slide vibration

Evaluation

  • No long term indications on crosshead slide (CHS) and rod position (RP)
  • No changing pressure gradient
  • Higher dynamic in RP signal
  • CHS peak nearly 2nd rod load reversal point decreases
  • CHS vibration is increasing nearly 1st rod load reversal point increases

Conclusion

  • Babbitt metal wear will be collected
  • Possibly caused with lower lubrication