某合成氨制尿素装置高压甲铵冷凝器在设备更新改造后的首次定期检验中,发现低压侧壳体焊缝处出现非正常腐蚀冲刷.为了保障设备运行的本质安全,通过收集设备运行数据、检测焊缝腐蚀程度、对比更新改造前后新旧设备的设计和制造方面存在的区别,最终发现设备原始设计缺陷和空泡腐蚀是导致异常腐蚀的主要原因,并依据分析结果合理地制定了检修策略,消除缺陷,降低装置运行风险.同时分享了高压甲铵冷凝器焊缝缺陷修复方案,为同类型设备出现相似缺陷提供借鉴.
关键词: 合成氨制尿素 / 高压甲铵冷凝器 / 异常 / 腐蚀 / 缺陷修复
Abstract:
ln a post-equipment-remolding synthetic ammonia-to-urea plant,abnormal corrosion was identified in the weld of the shel on the low pressure side of the high-pressure ammonium condenser in its first periodic inspection. To ensure intrinsic safety of equipment operation, various measures were taken such as collecting equipment operation data,detecting the degree of weld corrosion, and comparing the differences of equip ment in design and manufacturing before and after remolding. lt was finally found that the original equipment design defects and cavitation corro sion were the main causes behind this abnormal corrosion, based on such ana ysis result ,maintenance strategies were reasonably formulated to e iminate deects and reduce the risk in plant operation. At the same time,the repair scheme of high-pressure ammonium condenser weld defect is shared, which provides reference for treating similar defects in the same type of equipment.
Keywords: synthetic ammonia to urea / high-pressure ammonium condenser / abnormal / corrosion / defect repair