30c: Corrosive Chemicals in BFW, Defective Analysing Systemsand Incomplete Treatment of Steam Systems Resulting SeriousTransfer Line Exchanger Failures

摘要

The combination of insufficient means of Boiler Feed Water (BFW) quality control,chemicals dosage in BFW production, incomplete steam generation system chemicaltreatment/conservation, and pushing the demineralization plant capacity to limit, hasresulted in a series of serious quench exchanger damage at Borealis. As a minimumthe damage results in lost production and costly maintenance. In the worst case, thequench exchanger damage is a serious safety risk and has caused bad publicity andenvironmental contamination when Linear Exchanger failures resulted in suddendumping of BFW from the cracking furnace Steam Drum to the process side causingserious over pressure and opening of hot section RV's, which discharged heavy oilvapour to atmosphere. This paper reports a number of incidents that initiated theheavy and thorough investigation of root causes. Although it seems that the breakthrough of chlorine containing chemicals was the main cause of the problems, theinvestigation did reveal number deficiencies in BFW analysing systems, operatingmethods, chemical treatments etc. which together and individually could haveresulted same level problems sooner or later.