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题名	搅拌槽中液液固三相传质的实验研究
作者	方静
学位类别	硕士
答辩日期	2004
授予单位	中国科学院过程工程研究所
授予地点	中国科学院过程工程研究所
导师	杨超
关键词	搅拌槽 液液固三相体系 相间传质 电导率
其他题名	Preliminary Study on Interphase Mass Transfer of Liquid-Liquid-Solid Systems in a Stirred Tank
学位专业	化学工艺
中文摘要	液液固体系广泛应用于化工、石油、环境、新材料制备等工业中，但到目前为 止对液液固三相体系的流动和传递特性缺乏必要的认识。有必要对液液固三相体系 的传质规律进行深入地研究，为涉及液液固三相体系的多相反应和分离设备及过程 的科学设计和放大，提供正确的理论指导。由于液液固体系的传质机理复杂，涉及 因素多，目前几乎没有相关文献报道。针对这种情况，本文首次对液液固三相体系传质过程进行初步实验探索，对液 液固三相体系的流动和传质特性进行研究，探索复杂三相体系的流动和传质机理。 这将有利于寻找出具有适当的理论模型或经验关联式，来预测未知多相体系的传质 过程。本文选择欧洲化学工程师协会（EFCE）推荐的典型液液萃取体系“去离子水一丁 二酸一正丁醇”，在其中分别加入不同粒径的玻璃微珠（密度大、难悬浮）或聚对 苯二甲酸乙二醇醋（PET）（密度小、易悬浮）颗粒，构成液液固三相传质模型体 系。去离子水为连续相，正丁醇为分散相，溶质丁二酸传质方向是从分散相到连续 相。选择流动状况比较复杂的搅拌槽为传质测定的模型设备。利用电导率法在线测 定非稳态液液相传质系数，考察了搅拌转速（210 rPm-410 rpm）、固体体积百分含 量（玻璃微珠和PET分别为＜0.6 vol％和＜3 vol％）、不同桨型（标准RLlshtoll桨、 上推式和下推式450六折叶涡轮桨）、桨中心平面距槽底距离（D／6，D／4和D／3） 以及固体颗粒粒径（玻璃微珠和 PET分别为74-355μm和0.355-0.9 mm）对相间传 质的影响。在实验中设计加工了侧开孔的有机玻璃搅拌槽，建立了在线测量液液固体系传 质系数的实验设备和测量方法。通过实验给出实验数据校正方法，利用理论分析给 出数据拟合的依据和方法。实验结果表明，在液液体系中固体的加入对传质系数的改变因转速、桨型、固 体质量、固体粒径、桨中心平面距槽底距离等的不同而不同。对于玻璃微珠体系，随着搅拌速度增大，液液体系传质系数增大，固体的加入 强化液液体系传质；所用三种桨型中，Rushton桨的传质效果最好，上推式折叶桨 最差：随着加入玻璃微珠质量的增加，液液固三相体系传质系数有一极大值；玻璃 微珠的粒径对液液传质系数的影响不明显；桨中心平面距槽底距离对液液体系和液 液固体系的传质系数的影响规律相反，随着桨中心平面距槽底距离增大，液液体系 传质系数增加，而液液固体系在。3cm处有最小值。对于PET体系，随搅拌速度增大，液液体系的传质系数增大，PET颗粒的加入 抑制液液体系传质；三种桨型的传质效果和玻璃微珠体系得到的结论一致；随着加 入PET颗粒质量的增加，液液固三相体系传质系数减小；PET颗粒粒径对液液传质 系数的影响不明显；桨中心平面距槽底距离对液液体系和液液固体系的传质系数的 影响规律相反，奖中心平面距槽底距离对液液体系传质系数的影响规律和玻璃微珠 体系相同，液液固体系传质系数在C＝3cm处也有一最小值。对38组实验数据进行关联，得到体积传质系数与搅拌转速、固体颗粒粒径、固 体含量和搅拌桨安装位置的经验关联式。雷诺数的指数和文献中的关联式接近。液 液固三相体系的关联式计算结果和实验值之间的误差比液液两相体系的关联式计算 结果和实验值之间的误差大，可见，第三相固体颗粒的加入确实使液液体系的传质过程变得更为复杂。
英文摘要	Although liquid-liquid-solid systems occur frequently in chemical and petroleum industries, environmental engineering, new material preparation, biomass utilization and so on, little fundamental work has been reported on the mass transfer and hydrodynamic mechanism of liquid-liquid-solid systems due to the complexity of multiphase process and the difficulties involved in experimental techniques and numerical solution. In order to comprehend the mechanism of multiphase mass transfer and acquire reasonable parameters for design of high-efficiency process units, it is necessary to investigate the mass transfer process in liquid-liquid-solid systems deeply and systematically.Based on the previous research work on liquid-solid and liquid-liquid systems, the performance and discipline of interphase mass transfer of liquid-liquid-solid systems with inert particles were studied in this thesis. Volumetric liquid-liquid mass transfer coefficients were determined for liquid-liquid-solid dispersion in a mechanically agitated tank with internal diameter D=0.118 m and four vertical wall-baffles. The effects of agitation speed (210-460 rpm), inert solid particle (diameter of 74-355 urn for glass beads and 0.355-0.9 mm for PET, respectively), type of impeller, impeller-to-bottom clearance (D/6, D/4 and D/3), volume fraction of inert glass and PET particles (<0.6 vol% and <3 vol%, respectively) on the mass transfer of typical liquid-liquid extraction system, i.e. M-butanol-deionized water-succinic acid (solute), were examined. In all tests, the change of succinic acid concentration in the continuous phase (water) was monitored continuously by measuring the conductivity of the solution. The output signals were amplified by an amplifier and collected on-line through an A/D board into a PC computer. The volumetric mass transfer coefficients of liquid-liquid and liquid-liquid-solid systems were compared under the same operation conditions. The experimental results indicate that the mass transfer coefficients increase in liquid-liquid and liquid-liquid-solid systems when the agitation speed increases. The addition of glass beads enhances the mass transfer coefficients of liquid-liquid systems, but the addition of PET particles restrains this mass transfer process. In both liquid-liquid and liquid-liquid-solid systems, the Rushton impeller (standard Rushton disc turbine with six blades) is the most efficient one for mass transfer, and the mass transfer coefficient is higher than that for the other two pitched impellers (45"-pitched blade turbine upflow with six blades (PTU) and 45"-pitched blade turbine downflow with six blades (PTD)). The mass transfer coefficient shows a maximum in glass beads systems but decrease slightly in PET systems as the fraction of solid phase increases. The effect of diameter of glass beads on mass transfer of liquid-liquid system can be negligible, but the mass transfer coefficient increases slightly with increasing PET particle size. For the Rushton impeller, the effect of impeller-to-bottom clearance on glass beads and PET systems are partly different. The mass transfer coefficient has a minimum at C=Z)/4=3 cm for glass beads systems and increases straightly with the increase of clearance for PET particles. The experimental results are discussed in light of hydrodynamics in the stirred tanks. An empirical correlation for the liquid-liquid mass transfer coefficients of liquid-liquid-solid systems was also proposed, which represented the experimental data reasonably well.
语种	中文
公开日期	2013-09-16
页码	76
内容类型	学位论文
源URL	[http://ir.ipe.ac.cn/handle/122111/1431]
专题	过程工程研究所_研究所（批量导入）
推荐引用方式 GB/T 7714	方静. 搅拌槽中液液固三相传质的实验研究[D]. 中国科学院过程工程研究所. 中国科学院过程工程研究所. 2004.

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