Retrofit, Upgrade, And Demothball Of Two Crentrifugal Compressor Trains.

Abstract

The design premise in upgrading two operating plants for more compression capability is discussed. The first is a syn gas plant designed for 1000 tons/day of methanol but converted to syn gas only for a primary acetic acid market. The upgrade concentrates on a carbon monoxide (CO) compressor train which upstaged an original pair of compounded centrifugal compressor casings (15 impellers) to a larger casing (first body), roughly four sizes larger at 14 impellers compound compressor casings( two). The new train uses an available larger horsepower steam turbine available from the previous process conversion and its concrete mezzanine and intercoolers located just south of the present CO train. The timetable called for conversion in one year, plus shutdown and switchover at 30 to 45 days. The second upgrade required adding a third steam turbine driven centrifugal compressor air train, which had been "mothballed" some 13 years prior. The turbine and compressor rotors were vertically immersed in plant fabricated steel containers holding VSI inhibited ISO 43 turbine oil. The empty casings on a 20 foot mezzanine were coated with a tacky rust preventive and dead head blanketed with nitrogen. The time frame was 18 months. The intent of presenting these two conversions is to focus on the design considerations to be addressed for such a project to be successful and also upgrade the state of the art after 13 to 18 years.