Let’s discuss the causes of vibration in air compressor shafts
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Our air compressors are motor-driven, four-stage compression centrifugal compressors manufactured by Kaifeng Air Separation. Recently, it was observed that the vibration of one of the shafts on the high-pressure side increased by 50 um, reaching a maximum of 65 um. The oil temperature is kept between 33 and 38 degrees; the vibration level changes with the oil temperature, with higher oil temperatures resulting in greater vibration. But even when we keep the oil temperature at 35 degrees, the vibration still increases. All indicators of the oil analysis are within acceptable limits. The bypass valve for the intercooler was opened the day before yesterday; a large amount of water was found there. The vibration issue still persists, and the pressure on the low-pressure side also increased over the past few days, rising from 39 to around 45. There are no significant fluctuations in shaft displacement or oil temperature. Have any of you sea friends experienced this? Should I look for the cause in the equipment itself, or in the auxiliary devices (water content in the intercooler, oil temperature, oil supply volume, oil quality)?
Is the drain valve located after the inter-stage cooler of the air compressor not open? Similar phenomena may occur.
The drain valve remains open; whenever there is water present, it definitely flows through. What I want to know is whether this water has a direct impact on the vibration of the unit. If so, what is the extent of that impact?
There are many reasons for the high vibration in centrifugal compressors.
Leakage in the intercooler tube bundle is a high possibility.
Currently, the gas-side drainage involves gas-liquid entrainment, and the amount is not large. If that’s the case, how much of an impact does it have on shaft vibration?
During maintenance, the bearing shells can be checked to see if there is any carbon buildup or coking.
I think it’s necessary to take it apart for inspection; it’s been running continuously for 2 years now, so it’s time for a thorough overhaul
The axial vibration on the high-pressure side has increased by 50 um, reaching a maximum of 65 um. What are the alarm value and trip value?
Our vibration system does not have interlock; an alarm is triggered at 70