Large Vibrations on Centrifugal Compressor Caused by Inappropriate Operation During Mechanical Running Test

Abstract

Case StudiesDuring the mechanical test of a centrifugal compressor, the rotor experienced a sudden increase of the radial vibrations. After re-start, the compressor showed unacceptably high vibrations. The RCA revealed: The vibrations increased while running at trip speed close to surge. The shrink of the impeller, which had moved on the shaft, was too low to withstand these conditions. The impeller was removed and the shrink increased. After reassembly no high vibration appeared at trip speed anymore. Generally, the operation time at trip speed shall be reduced to its minimum and shall not be considered as “normal” continuous operation