延迟焦化加热炉炉管结焦原因分析及对策

通过对乌鲁木齐石化公司不同时期加工的延迟焦化原料的四组分含量及金属含量的变化分析,以及对辐射炉管结焦前后加热炉操作参数的对比分析,得出延迟焦化原料是一种饱和烃、胶质及沥青质含量高、芳烃含量低的易结焦渣油,在操作中宜采用较大循环比来提高芳烃与沥青质的比例,保证辐射炉管内冷油流速,控制好炉管壁温度,减缓加热炉炉管结焦,同时要对原料性质进行监控分析。

CAUSES ANALYSIS AND COUNTERMEASURES OF COKING ON FURNACE TUBE IN DELAYED COKING UNIT

Analysis on the variations of SARA content and metal content of the feedstock in delayed coking unit, and comparison of the operation parameters prior and post to coking on tube in radiation zone was carried out. It was found that residue feedstock high in saturated hydrocarbon, resin and asphaltene contents, low in aromatic content exhibited high coking tendency. Measures, such as using high recycle ratio to increase the ratio of aromatics to asphaltene and to speed up the flow rate of cold oil in radiation zone tubes, adjusting the wall temperature of furnace tube to suppress coking, monitoring the quality of the feedstock were adopted in operation to reduce coking on furnace tubes.