The Cryostar Magazine N°3 : pdf file

LIQUID TURBINELiquid turbine generates growthdesign features of a liquid turbine includedouble sealing philosophy, careful coldbarrier design and a comprehensive monitoringof crucial machine parameters.It all started in 1983 when Cryostarcommissioned its first liquid turbine forthe BOC Widness plant. This first liquidturbine was based on a Pelton wheel designand its isentropic efficiency level wasbetween 33-36 per cent.Soon afterwards a Francis wheel replacedthe Pelton wheel and efficiency levelssoared to values higher than 70 per centwith a liquid turbine that was commissionedfor BOC Scunthorpe in 1986.growing number of Cryostar customers areA opting for the ‘liquid turbine’ in combinationwith a conventional expander-generator orexpander-compressor unit. And with reportedpower savings of more than 500 kW and flexibilityof use, this comes as no surprise.Liquid turbines can be used in most of the liquefactioncycles (air separation, nitrogen liquefaction,LNG liquefaction, hydrocarbon processes, etc.).They are installed in parallel to the Joule-Thompsonvalve and are supposed to replace them duringthe operation of the plant.The growing popularity of the liquid turbine, thelatest addition to rotating machinery for industrialgas plants, is another example of Cryostar’s commitmentto research and development in order toprovide innovative engineering solutions.Over the years, Cryostar engineers conducteda number of design studies in order to satisfystringent customer requirements. The resultingWhat followed was a minute fine-tuning ofthis prototype over the next decade untilthe liquid turbine reached its technicalmaturity.In 1999, for the first time in its history, a liquidturbine – due to be commissioned for Air Liquide– underwent a full-load, full-pressure test atCryostar’s unique cryogenic test facility in France.The results were more than satisfactory – theturbine reached isentropic efficiencies of up to 84per cent.Since then, liquid turbines have become standardequipment installed in air separation plants andCryostar has seen many customers including thesein new plants, but also in existing plants since thepay back is so short!10Spring 2004