Abstract: A high-sulfur gas field is equipped with four natural gas purification processing units, each unit having two Claus blowers with one of them driven by steam turbine. The steam turbine-driven Claus blower serves as a critical energy-saving and environmentally friendly device within the sulfur recovery unit. However, its steam turbine has repeatedly experienced trips during startup and operation due to excessive vibration triggering the high-high interlock. Steam turbine maintenance is both time-consuming and complex, and these unexpected trips severely disrupt the normal production of the unit, as well as the regular use and maintenance of the equipment. This paper analyzed vibration trip data during steam turbine startup, along with on-site pipeline routing and mechanical operation conditions. The analysis confirmed that the primary cause of the trips was misalignment in the steam inlet and outlet pipelines of the steam turbine. To address the root cause of the turbine trips, improvements were implemented focusing on five key aspects: installing additional valves to the steam outlet pipeline, retrofitting steam turbine inlet and outlet pipelines, adding pipeline chain block, reinforcing pipe elbow supports and optimizing the types of pipeline supports. These modifications have effectively resolved the issue of unit trips caused by vibration, thereby ensuring the stable operation of the natural gas purification processing units.

Key words: steam-driven Claus blower, steam turbine, inlet and outlet steam pipelines, unit vibration, trip