焦化分馏塔多喷头喷淋脱除焦粉模拟研究

SIMULATION ON COKE POWDER REMOVAL BY MULTI-SPRAY IN COKER FRACTIONATOR

针对延迟焦化装置分馏塔中脱过热段人字形挡板脱除焦粉效果差,导致大量焦粉进入焦化蜡油和焦化柴油,造成产品不合格的问题,分别以水-空气-焦粉和焦化蜡油-油气-焦粉体系为对象,模拟3个喷头喷淋水滴和油滴脱除油气焦粉效果。结果表明:3个喷头布置方式以喷头与塔中心距离r和塔半径R之比为0.56的正三角形布置最佳;液相喷淋密度为2 m^(3)(m^(2)·h)、高气相负荷工况下,单层多喷头单向(S-T-S)喷淋水滴比单层单个喷头单向(S-S-S)喷淋水滴焦粉脱除率高约3%;S-T-S和S-S-S喷淋油滴焦粉平均脱除率均大于98.4%,二者相当;而S-T-S喷淋油滴和S-S-S喷淋油滴的焦粉最低脱除率分别比相应喷淋水滴时的焦粉最低脱除率高10.57%和11.43%,说明喷淋油滴洗涤脱除焦粉效果明显优于喷淋水滴;工业应用结果表明,采用喷淋技术可明显改善焦化分馏塔侧线产品质量。

In view of the poor removal effect of coke powder by the traditional herringbone baffle in the desuperheating section of coking fractionator of delayed coking unit,which results in a large amount of coke powder entering into coking gas oil and coking diesel oil,resulting in unqualified products,water-air-coke powder and coking gas oil-oil-gas-coke powder systems were used to simulate the removal of oil-gas coke powder by spraying water and oil droplets with three sprinklers respectively.The results showed that the best arrangement of the three sprinklers was the triangle with the ratio of the distance between the sprinkler and the column center(r)and the column radius(R)of 0.56.Under the conditions of the liquid spray density of 2 m^(3)(m^(2)·h)and the high gas load,the coke removal rate of single-layer multi-nozzle single-way(S-T-S)spray water droplets was about 3%higher than that of single-layer single-nozzle single-way(S-S-S)spray water droplets,and the average coke removal rate of S-T-S and S-S-S spray oil droplets was more than 98.4%.The minimum coke removal rates of S-T-S spray and S-S-S spray oil droplets were 10.57%and 11.43%higher than those of corresponding spray water droplets,respectively,which indicated that the effect of removing coke powder by spray oil drop washing was better than that by spray water drop washing.The results of commercial application showed that the product quality of side-line of coking fractionator could be improved obviously by using the multi nozzle spray oil droplet technology.