Liquid Ring Compressor failure Analysis Case Study

Problem

A petrochemical plant was experiencing cracks in the rotor of a liquid ring compressor and the OEM could not resolve the problem. KHE was contracted to perform a failure analysis of the compressor to determine the cause of the rotor cracks.

Solution

KHE conducted field measurements of the natural frequencies of the rotor, two axis vibrations of the compressor, and dynamic pressure pulsation on the suction and discharge chambers of the compressor. It was determined that, during specific transient operating conditions, the acoustic conditions allowed amplification of the positive displacement pressure pulses. These conditions all combined to overload the rotor which lead to the fatigue cracking.

Results

The controls of the compressor were modified to avoid running the compressor during the problematic transient operating conditions until the OEM could redesign the rotor to handle the transitional operating conditions that were causing the cracks.