聚并-分散脉冲筛板萃取塔的传质与轴向混合特性

A new configuration of coalescence-dispersed pulsed-sieve-plate extraction column (CDPSEC) was developed, and the mass transfer and axial mixing characteristics were evaluated with the two-point dynamic method.The influence of operation conditions was discussed with experimental results, showing that the mass transfer performance of CDPSEC mainly depends on the energy input and the holdup of dispersed phase. Higher energy input results in higher holdhp of the dispersed phase, the axial mixing of the continuous phase is suppressed, and the true height of mass transfer unit decreases markedly. On the other hand, higher energy input leads to more serious forward mixing of the dispersed phase, so the energy input should be limited. Accordingly the operation conditions were divided into two regions, and empirical correlations for predicting the mass transfer and axial mixing characteristics in different regions with a satisfactory accuracy were suggested.     

聚合-分散脉冲筛板萃取塔两相流动特性

A study on two-phase flow characteristics in a coalescence-dispersion pulsed-sieve-plate extraction column of 150mm in diameter was carried out with a working system of 30% tri-butyl-phosphate (TBP) (in kerosene)-nitric acid-water. The influence of operation conditions on the holdup of the dispersed phase was investigated. According to the analysis of the experimental data, there was a turning point on the curve of ln(Vs) versus ln(l-Φ) under certain pulse intensity. When the holdup is higher than the value at the turning point, the two-phase flow characteristics can be described with the modified Pratt's equation, otherwise a new relation in the form ofΦ=1/2.75uk(uc 4ud) may be used, which is proposed by this study.     

Axial Mixing and Mass Transfer Performance of an Annular Pulsed Disc-and-Doughnut Column

The annular pulsed disc-and-doughnut column (APDDC) is an important type of extraction equipment in the PUREX process, which has been used in several commercial reprocessing plants. As there are few mass transfer experimental results reported in the literature, the axial mixing and mass transfer performance of an APDDC was studied for both extraction and stripping processes in the present work. Two parameters in the axial dispersion model (ADM), namely, the axial dispersion coefficient of the continuous phase and the number of mass transfer units, were regressed by correlating ADM with experimental concentration profiles. The influence of flow rate and pulsation intensity on these parameters was also investigated. Models developed for the PDDC were tested for correlation with APDDC experimental data and suitable models and conditions were determined. The height of a mass transfer unit was also calculated, which highlights the impact of axial mixing on mass transfer performance. Moreover, the influence of internal wettability on mass transfer performance was discussed.     

Effects of Gas‐Agitation and Packing on Hydrodynamics and Mass Transfer of Extraction Column

The effects of gas‐agitation and packing on hydrodynamics and mass transfer were investigated through experiments with air‐kerosene (benzoic acid)‐water system and corrugated‐packing of calendering plate with hole. The holdup of gas, holdup of dispersed liquid phase and mass transfer coefficient increase and the flooding velocity decrease with the increase in superficial gas velocity. Over‐agitation of gas causes over‐dispersion and emulsification of dispersed liquid phase, reduction of mass transfer performance and even flooding. The mass transfer performance of a packed column is far better than that of an unpacked column.     

填料塔中牛血清清蛋白在聚乙二醇-硫酸铵双水相系统中的传质特性

研究了填料塔中牛血清清蛋白在聚乙二醇－硫酸铵双水相系统中的传质特性,测定了分散相含率和传质系数,用修正的Ｈａｎｄｌｏｌｓ－Ｂａｒｏｎ模型对实验数据进行关联,得到了相应的关联式,关联值与实验值相比,偏差小于５％。     

鼓泡床反应器内流动与传质行为的研究进展

总结了有关浆态鼓泡床反应器内流动、混合用气液传质特性的研究成果,详细地介绍了鼓泡床反应器内气含率、液速、液体轴向扩散系数、传质系数的测量方法,阐述了鼓泡床反应器性能的主要影响因素,如系统压力、温度、气体表观气速、液体性质及固含率等对流动、液相混合和传质特性的影响,并对鼓泡床反应器的应用前景进行了详述.     

Measurement of Mass Transfer Coefficients and Their Modelling of Continuous Counter-Current Aqueous Two-Phase System in a Packed Extraction Column

Overall dispersed side volumetric mare transfer coeffcieats for protein and amino acids were measured in continuous countercurreat PEG4000/KHP aqueous two-phase systems in a 57 mm I.D. packed extraction column. A model for overall dispersed side volumetric mass transfer coefficients was derived by describing the motion of the drops based upon Navier-Stokes equation combined with the relationship between mass transfer coefficients and the drop velocity. The model provides good predictions and can be successfully used in aqueous two-phase extraction. The awrage relative deviation between calculated values and experimental date ranges from 8% to 14%.     

梯形波脉冲筛板萃取柱传质性能

本文以UO_2(NO_3)_2—30％TBP(KO)为实验体系,进行了梯形波脉冲筛板柱传质性能的研究。实验中测量了两组分的两相稳态浓度剖面共13组,以扩散模型为基础,求得了梯形波脉冲柱的“真实”传质单元高度HTU_(ox),分散单元高度HDU及表观传质单元高度HTU_(oxp)。通过对实验结果进行分析,选择出了适于本实验体系的较好的操作条件。     

色谱法测定葡萄糖果糖在制备柱上的传质和扩散系数

色谱模型对研究色谱分离过程中的传质动力学具有重要的意义。根据物料守恒原理,结合传质扩散模型推导色谱分离连续方程。假设吸附过程相平衡是线性,连续性方程推导出理论板数与流速和色谱模型参数有关。在多组不同流速条件下测定色谱柱参数,计算得到两组分的传质系数和扩散系数。分别用测定模型参数模拟脉冲实验,结果表明拟合较好。     

浆态鼓泡床反应器气液传质特性的研究进展

本文总结了有关浆态鼓泡床反应器气液传质特性的研究成果。详细地阐述了主要影响因素如系统压力、温度、气体表观气速、液体性质,固体浓度及其物性等对传质特性的影响,并对浆态鼓泡床传质模型进行了归纳介绍,最后对反应器未来的研究方向进行了预测。     

Characteristics of a countercurrent reciprocating plate bubble column. II. Axial mixing and mass transfer

Oxygen absorption from air into water and axial dispersion in the aqueous phase have been measured in a 5 cm diameter reciprocating plate bubble column. The volumetric mass transfer coefficients in semi-batch conditions were found to increase with agitation and were correlated with the specific power input and air flow rate. Under countercurrent conditions, it was found that axial mixing had little effect and conditions approached plug flow. The volumetric mass transfer coefficients were correlated with specific power input, air and water flow rates. Mass transfer coefficients were estimated using holdup and bubble diameter results. Comparison of the coefficients with the literature values indicated that the bubble surfaces were partially mobile.     

脉冲筛板萃取柱内两相流动特性的规律

本文在以往工作的基础上，进一步研究了脉冲筛板萃取柱内两相流动特性的规律。讨沦了液滴群的相互影响，液滴的聚合效应，特性速度与单液滴终端速度的关系和液泛速度等问题，建立了相应的关联式。这一工作为脉冲筛板萃取柱的放大设计打下了基础。     

高温高压下浆态鼓泡床气液传质系数的测定

采用气体动态吸收法,对高温高压下浆态鼓泡床中气液传质系数进行了测定,考察了系统压力、温度、表观气速及固含量等操作条件对传质系数的影响. 结果表明,在温度298~473 K、气体压力1.0~3.0 MPa、表观气速0.03~0.10 m/s、固含量0%~20%(w)的实验条件下,体积传质系数随着压力、温度及表观气速的增加而增大,随固含量的增加而减小. 同时对不同塔径的传质系数进行了比较,表明在相同的操作条件下,大塔的传质系数略高于小塔.     

多级搅拌塔气液液系统的轴向混合

本文在内径为５４ｍｍ，级数为１６的多级搅拌塔中，研究了空气－水－煤油系统的轴向混合性质。讨论了搅拌转速、水相流速、有机相流速及气相流速对液体连续相和分散相轴向混合的影响。得到了操作范围内描述塔内轴向扩散系数的关联式。对连续水相：Ｅｃ＝０．７４５·Ｎｓ０．５３０·ｕｇ０．４５９·ｕｃ０．６９１·ｕｄ０．３１９对分散有机相：Ｅｄ＝２１．９２·Ｎｓ０．４６５·ｕｇ０．８９８·ｕｃ０．２５８·ｕｄ０．７６２     

填料类型对脉冲填料萃取塔性能的影响

采用３０％ＴＢＰ（煤油）／ＨＡｃ／水体系研究了脉冲填料萃取塔的流体动力学和传质特性,考察了脉冲强度和填普类型对塔性能的影响。实验表明装填ＱＨ－１型扁环的脉冲填料 性能明显优于装填陶瓷和不锈钢拉西环的脉冲塔。文中给出了装填ＱＨ－１型扁环的脉冲填普塔的特性速度和Ｈｏｘｐ的经验计算式。     

Axial mixing and mass transfer in a vibrating perforated plate extraction column

The axial mixing and countercurrent mass transfer characteristics of a 5 cm diameter extraction column agitated by vibrating perforated Teflon plates have been investigated. The dispersed phase was an organic liquid (usually kerosene) and the continuous phase was water. Axial mixing was measured in both phases using pulse tracer techniques; in the continuous phase the axial mixing was estimated to have a significant effect on mass transfer, but axial mixing in the dispersed phase had a negligible effect. Mass transfer was measured for several different solutes; n-butyric acid, benzoic acid and phenol. The overall heights of a transfer unit (cont. phase) were in the order of 10-20 cm for the organic-acids but higher for transfer of phenol from very dilute solutions. The characteristics of the vibrating plate column have been compared with those of other types of extractor and suggestions are made for further development.     

Hydrodynamics and Mass Transfer in a Lab‐Scale Stirred‐Pulsed Extraction Column

An extraction column with energy input through simultaneous stirring and pulsation allows for efficient countercurrent extraction on lab‐scale. While stirring generates small droplets with a narrow droplet size distribution, pulsation supports the axial transport of the dispersed phase, enabling countercurrent flow on this small scale. By studying the influence of several operating parameters, fundamental mechanics and characteristics of the column are revealed. Increasing the stirrer speed leads to smaller droplets and higher extraction performance as well as lower maximum throughput. The maximum throughput is increased by raising the pulsation intensity.     

高温高压浆态鼓泡床反应器中的气-液传质

The gas-liquid mass transfer of H2 and CO in a high temperature and high-pressure three-phase slurry bubble column reactor is studied. The gas-liquid volumetric mass transfer coefficients kLa are obtained by measuring the dissolution rate of H2 and CO. The influences of the main operation conditions, such as temperature, pressure,superficial gas velocity and solid concentration, are studied systematically. Two empirical correlations are proposed to predict kLa values for H2 and CO in liquid paraffln/solid particles slurry bubble column reactors.     

微通道中液-液萃取传质特性的研究

研究了在一个内径为400 μm管式直线型玻璃微通道中的液-液两相的传质特性,其中去离子水为水相, 煤油（溶质是苯甲酸）为油相, 氮气为气相。实验研究了表面张力、黏度和气体分散相对体积传质系数的影响,结果表明：在内径为400 μm的微通道内,当停留时间为15 s时微通道内的萃取已达到平衡;水相的表面张力和液体黏度显著影响微通道内的传质效率;在液-液系统中引入气相后,水油两相之间的传质效率显著增加。     

立体传质塔板在乙酸甲酯精馏技改中的应用

选用立体传质塔板取代原乙酸甲酯萃取精馏塔的泡罩塔板进行技术改造,改造后扩产44％,节能约20％,塔压降减小43％,提高了产品质量,降低了原料消耗,技改的设备投资20万元,年增经济效益58．8万元,投资回收期为4个月。