【作者】 胡雪沁；

【导师】 刘春江；

【作者基本信息】 天津大学 ， 化学工程， 2009， 硕士

【摘要】 在液液萃取过程中,分散相液滴在连续相中的流动方式对传质效率有着重要的影响,研究发现,当分散相呈现液滴-液膜-液滴-液膜……交替流动(简称滴膜交替流动)时,传质效率可以得到大大提高,为此开发了一种可以实现滴膜交替流动的组合规整填料并对其传质性能进行了研究。论文首先采用实验的方法对新型规整填料的萃取性能进行了测试。实验在φ150mm的填料萃取塔中进行,实验体系为30%磷酸三丁酯(简称TBP)+煤油-醋酸-水。实验测定了不同操作条件下不同填料的表观传质单元高度,结果表明:在相同的操作条件下,组合规整填料的表观传质单元高度较鲍尔环填料平均降低了58%。第二,本文还通过计算流体力学(CFD)方法,对滴膜交替流动现象进行了流动与传质性能模拟,作为对比,同样模拟了传统规整填料的单液滴传质。采用的物系为中等界面张力的乙酸丁酯-丙酮-水。模拟结果表明:采用滴膜交替流动的方式,计算所得进出口浓度差比波纹板要大10.8%,从另一个角度说明采用滴膜交替流动方式具有一定的优越性。在实验室研究及理论研究的基础上,利用新型填料进行了初步的工业实验,对某药厂的醋酸废水的进行了萃取实验。初步实验结果表明,当废水中醋酸浓度大于3%时,新型填料优势并不明显,但当废水中醋酸浓度低于3%时,采用新型填料的萃取率最高比原工业装置的350Y填料高21%。工业实验发现固定油水两相流量比为1:1,当两相流量均为0.15m3/h时的萃取率最高。更多还原

【Abstract】 For liquid-liquid extraction process, the flow pattern of the dispersed phase is of great importance in determining the mass transfer efficiency. Primary experiment revealed that the mass transfer efficiency improved dramatically when dispersed phase realized droplet-film alternate flow rather than only droplet flow. Based on this phenomenon, a novel hybrid structured packing that suitable for liquid-liquid extraction was developed and the mass transfer performance of the packing was investigated.Firstly, the mass transfer performance of different packings including the novel hybrid structured packing was measured by experiment. Experiment was carried out in a 150mm in diameter extraction column. 30% TBP (kerosene)-acetic acid-water was selected as the test system. The apparent height of mass transfer unit (HTU) of different packings was calculated using the experimental data. Result showed that in the same operating condition, novel structured packing can get the best mass transfer efficiency, and the HTU of which was 58% lower than pall ring in average.Secondly, mass transfer and flow pattern of droplet-film alternate flow were simulated using the computational fluid dynamic (CFD) method. In order to compare the mass transfer efficiency of this kind of flow, flow pattern occurred in traditional structured packing was also simulated. Butyl-acetate-acetone-water with medium surface tension was selected as the test system. Results showed that the concentration difference between inlet and outlet of droplet-film alternate flow was 10.8% higher than traditional structured packing. It showed that the simulated result was coincident with the experiment.Based on laboratory and theoretical research, the novel hybrid packing was applied to carry out industrial experiment. Acetic-acid was separated from the waste water of a pharmaceutical factory. Primary result showed that the advantage of novel hybrid packing was not obvious when the mass concentration of acetic-acid in waste water was larger than 3%. When the concentration was lower than 3%, the extraction ratio of novel hybrid packing was 21% higher than Mellapac 350Y. Fix the two phase flow rate ratio as 1:1, the extraction ratio reached highest when both of the two phases flow rate were 0.15m3/h.更多还原