Oil Mist Eliminator Vessel Modifications for GE 7EA Gas Turbine

With any rotating machinery as lube oil leaves bearings, a certain amount of lube oil is aerated, resulting in the formation of a mist of very small size (less than 1 $μm$ diameter) particles. If oil mist elimination system is not sized and designed properly, it could cause various issues such as increased operation and maintenance cost, re-entry of oily air into adjacent gas turbine units, fouling of surrounding atmosphere, and creation of oil slick on concrete floors, besides impacting environmental requirements and safety hazards. This paper presents a case study involving GE 7EA gas turbines operating at the Watson Cogeneration Plant and discusses issues with the existing oil mist elimination system and steps taken for a successful replacement of the original equipment manufacturer (OEM) supplied mist elimination system with non-OEM designed and fabricated mist elimination system. The replaced system demonstrated significantly higher life expectancy than it was designed for.