(31c) Corrosive Chemicals in Bfw, Defective Analysing Systems and Incomplete Treatment of Steam Systems Resulting Serious Transfer Line Exchanger Failures

The combination of insufficient means of BFW quality control, chemicals dosage in BFW production, incomplete steam generation system chemical treatment/conservation, and pushing the demineralization plant capacity to limits, has resulted in Borealis a series of serious Quench Exchanger damages. As a minimum the damage always results lost production and costly maintenance. In worst case, the Quench Exchanger damage is a serious safety risk and have caused bad publicity and environment contamination when Linear Exchangers failure resulted sudden dumping of BFW from cracking furnace Steam Drum to process side causing serious over pressure and opening of hot section RV's, which discharged heavy oil vapour to atmosphere. The paper reports a number of incidents that initiated the heavy and thorough investigation of root causes. Although it seems that the break through of chlorine containing chemical was the main cause of the problems, the investigation did reveal number deficiencies in BFW analysing systems, operating methods, chemical treatments etc. which together contributed and alone could have resulted same level problems sooner or later.