Investigation and Resolution of Propane Compressor High Axial Position Alarm

Abstract

Propane compressor in Propane Dewaxing Unit was experiencing intermittent high axial spikes coinciding with the chiller swing. The axial spikes were due to compressor surge caused by sudden drop in flow during chiller swing. The response and the tuning of the anti-surge controller (ASC) was set in a generic way to suit steady state operation. But this being a semi-batch process, the ASC retuning was required. ASC retuning was done to suit to the process conditions. By doing so, the compressor surge was avoided and the axial position spikes were also eliminated.