延迟焦化装置分馏塔腐蚀原因分析及改进措施

对中国石化洛阳分公司延迟焦化装置在检修期间发现的分馏塔顶部塔盘存在不同程度的腐蚀问题进行分析，认为造成分馏塔顶部塔盘腐蚀的主要原因为焦化原料和回炼重污油的盐含量高、分馏塔水洗操作不当。结合装置的原料性质、操作参数及设备条件，采取加强原料盐含量监控、改善分馏塔上部热量分布、增设分馏塔顶部水洗专用线、优化分馏塔侧向回流等一系列改进措施，改善了分馏塔的结盐现象，为保证装置的长周期运行奠定了基础。

CORROSION CAUSE ANALYSIS OF FRACTIONATOR IN DELAYED COKING UNIT AND IMPROVEMENTS

Corrosion of trays at the top part of fractionator in delayed coking unit of SINOPEC Luoyang Petrochemical Company was detected during revamping, thus, an analysis of corrosion causes was carried out. It seemed that using high salt feed and recycling heavy waste oil with high salt and high water content were the main causes, as well as improper operation of washing step. Considering the feed properties, operation parameters and equipment conditions, some countermeasures were applied, such as strengthening the monitoring of salt content in feed, improving the heat distribution at the top part of fractionator, adding a water pipe for washing at the top part of fractionator, optimizing the side streams recycle and so on. Since then, the salt deposition in fractionator was improved significantly, and it is good for a long-term operation.