In order to guarantee sufficient production efficiency of plant assets and avoid unplanned downtime, investigating reasons for undesired turbine trips is key in chemical industries.
The case story describes here the study carried out to determine the root cause of a blade failure in a turbo-generator machine train. With that purpose, it is necessary to analyze machine vibrations with flexible and controlled tools providing all details of the rotor dynamics, based on the turbomachinery vibration OROS solution, ORBIGate. Based on proximity probes, accelerometers, as well as other data such as rotating speed fluctuations, vibrations are carefully analyzed to obtain typical graphs allowing diagnosing the machine issues leading to blade vibrations and failure. In particular, the unexpected shape of the shaft centerline obtained after a machine run-up was studied to have a better understanding of the high-speed rotor behavior.
Finally, other typical turbomachinery tools and methodologies, such as torsional vibrations, ODS, end winding modal testing, sound intensity, and rotor balancing allowing to solve such problems are considered and described.