延迟焦化装置蜡油反冲洗过滤器存在的问题及对策

Problems and Countermeasures for Gas Oil Backwash Filter in Delayed Coking Unit

洛阳石化焦化蜡油中焦粉含量高,直接进入加氢处理反应器后,会在加氢催化剂表面沉积,致使催化剂床层压力降升高,发生架桥、偏流等现象,甚至导致催化剂失活。为减少焦化蜡油中焦粉对渣油加氢装置的冲击,焦化装置增上了ZFG-Ⅱ型蜡油自动反冲洗过滤器,蜡油反冲洗过滤器出现了频繁的反冲,通过对焦化装置分馏塔关键参数进行分析,发现蜡油反冲洗过滤器频繁反冲的主要原因是分馏塔洗涤过热段的洗涤作用发挥不好,造成焦粉在蜡油段集聚,同时对装置蒸发段温度、分馏塔的重蜡下回流和循环油上回流参数进行了调整,解决了蜡油反冲洗过滤器频繁反冲的问题;同时通过优化改造,将蜡油反冲洗过滤器的污油和污油罐顶的气相改至接触冷却塔,解决了污油对分馏塔的冲击和重污油罐顶VOCs排放不合格的难题,保证了蜡油反冲洗过滤器的平稳运行。

Due to the high coke powder content of the coker gas oil of SINOPEC Luoyang Company,if the coker gas oil directly enters the hydrogenation reactor,the coke powder will deposit on the surface of hydrogenation catalysts,resulting in increased pressure drop of catalyst bed,catalyst bridging and deflection,and even catalyst deactivation.In order to reduce the impact of the coke powder in coker gas oil on the residue hydrodesulfurization unit,the coking unit was equipped with a ZFG-Ⅱ automatic gas oil backwash filter.Frequent backwash occurred in the gas oil backwash filter.By analyzing the key parameters of fractionating tower in the coking unit,it was found that the main reason for the frequent backwash in the gas oil backwash filter was the poor washing function of the washing overheating section in fractionating tower,which resulted in the accumulation of coke powder in the gas oil section.The temperature in evaporation section of the unit and the lower heavy gas oil reflux and upper circulating oil reflux in the fractionating tower were adjusted,solving the frequent backwash problem of the gas oil backwash filter.At the same time,through optimization and transformation,the dirty oil from the gas oil backwash filter and the gas phase from the top of slop oil tank were transferred to the contact cooling tower,thus solving the problems such as the impact of dirty oil on fractionating tower and the non-compliant emission of VOCs from the top of heavy slop oil tank and en-suring the smooth operation of the gas oil backwash filter.