蜡油加氢裂化装置高压换热器结垢物分析及建议

ANALYSIS OF SCALE SAMPLE IN HIGH PRESSURE HEAT EXCHANGER OF VGO HYCROCRACKING UNIT AND SOLUTIONS

针对某炼油厂蜡油加氢裂化装置高压换热器因结垢而换热效率大幅降低、压降上涨的现象,在停工消缺过程中对高压换热器进行清洗并取样分析。对所取垢样进行甲苯抽提处理后采用X射线荧光光谱仪、扫描电子显微镜和X射线衍射仪等手段进行检测。结果表明:垢样的主要无机成分为Fe2P4O12和FeS,此外还有少量含Si、含Na的无机物以及少量的有机垢。对此,建议炼油厂严格控制加氢裂化原料油中含P物质的携带,同时要尽可能做好环烷酸对设备和管线腐蚀的防护。

In view of heat exchange efficiency reduction of the high pressure heat exchangers of VGO hydrocracking and the pressure drop continuously rise,the high pressure exchangers were cleaned and the scale samples were analyzed.The X-ray fluorescence spectrometer(XRF),scanning electron microscope(SEM)and X-ray diffractometer(XRD)and other analysis techniques were used to analyze the sample after toluene extraction.The results showed that the main inorganic components in scale sample were Fe2P4O12 and FeS.In addition,it also contained a small amount of inorganic materials containing Si and Na and a small amount of organic scales.In view of this,it is suggested that refineries strictly control the carrying of phosphorus-containing substances in hydrocracking feed oil,and protect equipment and pipelines from corrosion by naphthenic acid as much as possible.