Causes of corrosion failures in evaporator tubes in sugar factories and determination of corrosive properties of juices

CAUSES OF CORROSION FAILURES IN EVAPORATOR TUBES INSUGAR FACTORIES AND DETERMINATION OF CORROSIVEPROPERTIES OF JUICES(M.Sc. Thesis)Selda ALTANLARGAZI UNIVERSITYINSTITUTE OF SCIENCE TECHNOLOGYJanuary 2006ABSTRACTIn this study, causes of corrosion failures in evaporator tubes of sugarfactories were investigated. Evaporator tubes are made of St 37.2quality steel in general and some of them are made of stainless steel.During campaign period, inner side of tubes was corroded and thetubes were failed. Corrosive properties of juices, high temperature,aerated cells rich by oxygen, and steels quality were thought as thereasons of this type of corrosion. For this reason measurements weremade in Eskişehir, Ankara and Afyon Sugar Factories juices. pH, Bx(refractometric dry matter), corrosion rate, amount of dissolved oxygen,chloride were measured in juices from thin juice to thick juice inevaporator stages for factories. Polarisation curves of the juices wereobtained by using stainless steel and St 37.2 quality steel electrodes.As a result of this study, stainless steel is more suitable than St 37.2 inevaporator tubes.Science code : 201.1.041Key Words : Sugar processing, evaporator tubes, evaporatorjuices, St. 37.2 quality steel, stainless steel,corrosionPage number : 81Adviser : Prof.Dr.Melike KABASAKALOĞLU