TITANIUM EXCHANGE TUBES FOR MSF DESALINATION PLANT - A STUDY ON THE ASPECTS RELEVANT TO THE ADOPTION OF THIS MATERIAL

The excellent resistance of titanium to erosion and corrosion in sea w ater makes this material most interesting for applications in power co ndensers and desalination plant heat exchange tubes. The low thermal c onductivity and the relatively high cost can be compared with copper n ickel tubes, the main alternative to titanium which is interesting onl y if very thin tube wall thickness is considered. Till now, copper all oys still remain the most suitable materials for tubeplates due to the easy weldability to carbon steel which is adopted for evaporator shel l and collars and due to the absence of crevice corrosion which can oc cur when using titanium or titanium clad tubeplates [1]. Thus more inv estigation on tubing and corrosion is necessary than that available in the literature. In Section I experiments are described on tubing thin wall titanium tubes to copper nickel tubeplates which can be taken as a first approach to work out a tubing procedure and specification. Se ction II is dedicated to aspects of corrosion involved in the adoption of titanium due to galvanic corrosion when coupled to copper nickel t ubesheet.