采用粉末X射线衍射分析,结合扫描电镜-能谱分析、傅里叶变换红外光谱分析和碳氢元素分析等方法对某乙烯装置急冷换热器的垢样形成原因进行了分析。结果表明: 该垢样是烃类裂解气中的二氧化碳与裂解物料中的微量钙离子反应生成的方解石、铁电化学腐蚀产生的磁赤铁矿、磁铁矿和赤铁矿晶体以及烃类裂解反应的缩合产物非晶碳等在急冷换热器上缓慢结垢形成的;可见粉未X射线衍射法辅以人工智能可以快速、准确地鉴定出乙烯装置急冷换热器垢样中的晶体物相。

Formation reasons of fouling of the rapid cooling heat exchanger for ethylene plant were analyzed by methods of powder XRD combined with SEM-EDS, FTIR, and elemental analysis of carbon and hydrogen. The results show that the fouling of rapid cooling heat exchanger were slowly formed from reaction of carbon dioxide in hydrocarbon pyrolysis gas and trace calcium ion in cracking material to produce calcite, iron’s electrochemical corrosion products of magnetite, maghemite and hematite crystals, and hydrocarbon cracking reaction’s condensation product of amorphous carbon. The application shows that powder X-ray diffraction method combined with artificial intelligence can quickly and accurately identify crystal phase in the fouling of rapid cooling heat exchanger for ethylene plant.