Fouling of steam turbine blades and vanes is a common problem. A complete and thorough cleaning would require stoppage and opening up the turbine, which may mean shutting down a profitable process. Online cleaning is possible that doesn’t require dismantling although the results are not guaranteed.
This article features excerpts from a case study, “Successful Online and Offline Cleaning of Steam Turbines With and Without Disassembly” by Bladimir Gomez Supervisor of PDVSA and Barry Snider of Small Hammer Inc. at the 43rd Turbomachinery Symposium held in Houston in 2013.
At a facility, the steam turbines driving critical compressors were losing power and speed. The governor/steam valve was unable to maintain desired rpm. Unit production reduced and revenue loss was occuring. The cause of the problem was fouling of turbine rotor blades and static guide vanes. The fouling was water soluble chemicals [NaCl, NaOH] bound with insoluble oxides [Fe, Si, Al] > 50 ppb.