Application of a Particle Extraction Process at the Interface of Two Liquids in a Drop Column—Consideration of the Process Behavior and Kinetic Approach

The focus of this research is a new type of particle extraction process for the transfer of magnetite nanoparticles from an aqueous to an immiscible organic phase, directly through the liquid-liquid phase boundary in a drop column. The particle extraction process comprises several advantages such as a minimum amount of stabilizing surfactant, no exposure of the particles to a gas atmosphere and with it the avoidance of sintering by capillary forces and a high particle concentration in the receiving phase as well. The study presents experimental results of the characterization of the process environment and the transfer behavior in a drop column. The solution of surfactant in the continuous phase has been investigated during a particle-free phase transfer experiment including the measurements of the total organic carbon (TOC) content and analysis of the size of the stabilized droplets using the laser diffraction spectroscopy. The determination of the transfer fluxes, the mass flows as well as the yield of transferred magnetite by ICP-OES measurements provide information on the impact of interaction of the elementary processes at the phase boundary. Furthermore, the transfer kinetics of the process is described and compared with calculated theoretical values resulting from a kinetic approach.

Kinetics of gadolinium extraction with D2EHPA and Cyanex301 using single drop column

The extraction kinetics of Gd（III） from the nitric acid medium using bis（2,4,4-trimethylpentyl） dithio- phosphinic acid （Cyanex301） and 2-ethylhexyl phosphoric acid （D2EHPA） in kerosene solution were measured by the single drop technique. The influences of hydrogen ion concentration, gadolinium ion concentration, extractant concentration, column height, and nozzle diameter on the extraction rate were investigated. The forward rate equations for the gadolinium extraction with D2EHPA and Cyanex301 were obtained. Based on the experimental results, the forward extraction rate constant was calculated. With the increase of D2EHPA or Cyanex301 concentration, the drop rising diameter and the value of interfacial tension decrease in the studied system, which shows that D2EHPA or Cyanex301 has interfacial activity as a kind of surfactant. Also, the droplet diameter and interfacial tension decrease with the increase of aqueous solution acidity. The experimental results show that the D2EHPA extractant provides faster extraction rate in comparison with Cyanex301 extractant, and it would be useful in industrial continuous extraction process.

GRAVITY SETTLING OF DISPERSED PHASE DROP SWARMS IN EXTRACTION COLUMNS IN ABSENCE OF MASS TRANSFER

Taking into account the effect of velocity profiles of the continuous phase in interstices of drops,dragcoefficient and relative motion correlations for dispersed liquid-liquid two-phase flow in absence of mass transferwere developed in terms of the pseudo-fluid concept based on the simple similarity criteria and the mixtureviscosity model suggested by Ishii and Zuber.The present model was compared with the experimental data fromfive(different sources and also with seven other pertinent correlations available in literature.Fairly goodpredictions were obtained under wide ranges of the dispersed phase holdup and Reynolds number.The validity ofthe present model has also been checked against the experimental slip velocity data and holdup data obtained ina Karr reciprocating plate extraction column by the author of the present paper and satisfactory agreement isachieved、The results show that the equations of the motion of a multi-droplet system can be formulated in aform identical with those for a single

冲击荷载作用下钢管再生混凝土柱损伤评估分析

为研究钢管再生混凝土柱在冲击荷载作用下的损伤,进行了16根钢管再生混凝土柱的落锤冲击试验。在试验的基础上建立了钢管再生混凝土柱的有限元模型,分析不同冲击速度、冲击质量、截面含钢率对钢管再生混凝土柱损伤程度的影响。通过控制冲击质量与冲击速度,基于损伤因子d_(s)和弹塑性转角θ,划分损伤评估等级,拟合钢管再生混凝土柱损伤评估曲线。结果表明:建立的有限元模型能很好地吻合落锤冲击试验的结果,最大误差不超过10%;冲击过程中跨中挠度峰值出现时间远远滞后于冲击力峰值出现的时间,冲量是动量的1.23倍;随着冲击速度的增加,跨中挠度呈抛物线形的增长趋势,冲击质量增加对冲击力峰值影响较小,但对跨中挠度有较大影响,随着截面含钢率的增加,构件的耗能几乎稳定在90%附近;从损伤曲线图可以快速判断钢管再生混凝土柱的整体损伤情况及局部损伤情况。

水平冷缝对大荷载无梁楼盖及类似结构的影响

首先,介绍了托板上水平方向施工冷缝对无梁楼盖顶板抗冲切承载力的不利影响,列举了3个不同地区地下车库坍塌的工程实例。其次,介绍了容易导致无梁楼盖顶板的托板或相似部位出现水平施工冷缝的3种情况。最后,给出了对投入使用的无梁楼盖结构加强日常检查的建议,一旦发现托板部位存在竖向折断裂缝,应立即采取应急措施以防止坍塌事故的发生。

脱硫塔煤气分布器的模拟分析及优化研究

介绍了煤气净化工程脱硫塔中应用的直管开孔式煤气分布器和双列叶片式煤气分布器的主要结构及分布特性。在同等条件下采用Flow Simulation软件分别模拟两种煤气分布器的流动情况,进行流场、压力降、均匀性指数分析,并对低压降的双列叶片式煤气分布器进行结构优化。研究双列叶片式煤气分布器的均布性能和压降性能随不同导流叶片数量的变化规律,提升分布器的分布效果。

Design aspect of a novel L-shaped pulsed column for liquid–liquid extraction applications: Energy consumption and the characteristics velocity concept

This article deals with the evaluation of the consumption of energy for a steady state solvent extraction in a novel L-shaped pulsed sieve-plate column, which is highly required for design and optimization of the periodic flow processes for industrial applications. In this regard, a comprehensive evaluation on the energy consumption in case of a pulsed flow for three different chemical systems is conducted and besides the influence of pulsation intensity, the effect of geometrical parameters including the plate spacing and the plate free area is investigated as well. Moreover, the concept of characteristic velocity models at flooding points is evaluated with respect to the variation of pressure drop along the column at different operational conditions.

Experimental Investigation of Pressure Drop Hysteresis in a Cocurrent Gas-Liquid Upflow Packed Bed

Extensive experimental work on hysteresis in a c℃urrent gas-liquid upflow packed bed was carried out with three kinds of packings and the air-water system. However, only when packed with small glass beads ((1.4 mm) was the bed pressure drop hysteresis observed. Two more liquids with different liquid properties were employed to further examine the influence of parameters on pressure drop hysteresis. The similarity of pressure drop hysteresis in packed beds was concluded in combination of experimental evidence reported in literature.

Novel predictive tool for accurate estimation of packed column size

Traditionally the majority of fractionation columns in natural gas processing plants were equipped with trays.However an option to trayed columns is to use packing.Packed columns offer a larger surface area per unit volume for mass transfer and the continuous gas to liquid contact throughout the column rather than at specific levels （such as in tray columns）.For process design purposes,it is essential to estimate the pressure drop for enabling the proper operation of packed columns.In this study,a simple generalized pressure drop correlation （GPDC） which is easier than existing approaches requiring more complicated and longer computations is developed for sizing randomly packed fractionation columns for pressure drops up to 150 mm water per meter of packing.This correlation can be used to estimate pressure drop for a given loading and column diameter.Alternatively,for a given pressure drop the diameter can be determined.The predictions from the proposed correlation have been compared with reported data and found good agreement with average absolute deviation hovering around 4.9%.The proposed predictive tool is superior owing to its accuracy and clear numerical background,wherein the relevant coefficients can be retuned quickly if new and more accurate data are available in the future.This proposed simple-to-use approach can be of immense practical value for the engineers and scientists to have a quick check on the pressure drop in packed columns for a given loading and column diameter.In particular,gas engineers would find the proposed approach can be used very friendly involving no complex expressions with transparent and easy-to-handle calculation steps.

Hydrolysis of Olive Oil with Immobilized Lipase in a Tapered Column Reactor

Lipase was immobilized in ion exchange resin and then used in the hydrolysis of olive oil to produce fatty acids and glycerol. The time course of hydrolysis of olive oil was investigated in a stirred tank reactor using both of the free and immobilized lipases to find the yield of activity of immobilized enzyme. Continuous hydrolysis of olive oil was also carried out in a tapered column reactor and a cylindrical column reactor with a bottom ID of 10 mm at different upward flow rates. It can be known from experimental results that the degree of hydrolysis of olive oil in the tapered column reactor is moderately better than that in the cylindrical column reactor, the pressure drop in the tapered column reactor is much smaller than that in the cylindrical column reactor.

液压支架双伸缩立柱落锤冲击特性仿真分析

为掌握冲击载荷作用下液压支架立柱及其安全阀的冲击特性及流量匹配规律,在分析落锤冲击载荷及立柱结构的基础上,以某型液压支架双伸缩立柱为例建立了其落锤冲击模型及AMESim仿真模型,并对其冲击特性进行了分析。研究结果表明:在冲击载荷作用下,活柱由于底阀的存在无法实现位移缩让,在介质压力能的作用下会形成上下振动,中缸由于安全阀可以产生较大的瞬间冲击流量实现缩让,不易形成位移振动;而当存在2次冲击时,第2次冲击产生的立柱冲击压力比第1次冲击产生的压力大;且随着安全阀流量压力梯度的增加,大缸及中缸的第1次冲击压力都是逐渐减小,而第2次冲击压力存在先减小后增大的趋势。

氢-水液相催化交换床压力降及液泛研究

在50mm×680mm和20mm×290mm玻璃柱中,用氢 氘水研究了催化交换床层不同填料的液泛及床层压力降的变化。结果表明:活性Al2O3填料、不锈钢θ填料、不锈钢三角填料装填的床层在相近操作条件下,θ填料泛点气速为高;相同气速下,升高温度和增加液体喷淋密度均使床层压力降升高。压力降随液体喷淋密度l、床层气速μ变化的经验关联式为Δp=14758 8×100 0164lμ1 91。

纳米增强型毛细管酶柱用于葡萄糖液滴生物传感器的研究

An effective and fast method for assay of micro-amounts of glucose was set up. A new technique for preparation of enzyme columns based on enzyme immobilization by sol-gel was investigated. Glucose oxidase(GOD) and horseradish peroxidase(HRP) mixed with SiO 2 nanoparticles and polyvinyl butyral(PVB) medium were immobilized on the surface of capillary tube, respectively. The experimental results show that nanoparticles can significantly enhance the catalytic activity of immobilized enzyme. Based on GOD column and HRP column, a liquid droplet sensor was developed for the determination of glucose solution. The effect of separated columns and mixed columns on the response of glucose sensor was investigated. The sensor showed a linear response in a range of 2-400 ng/mL with a detection limit of 0.3 ng/mL under the optimum conditions. The characteristics of the sensor including effect of flow-rate, pH and temperature were discussed.

乳状液膜法分离氨基酸的动力学

探讨了含载体P2 0 4 (磷酸二异辛酯 )的液膜体系用于苯丙氨酸促进运输的动力学行为 .采用液滴法装置 ,控制实验条件 ,测定了内相氢离子浓度随时间的变化 ,适用于有机相界面的化学反应对溶质传递的影响 ,并将计算的结果同实验相比较 ,建立了水相

氢同位素催化交换过程影响因素研究

氢-水催化交换反应是研究氢同位素分离的重要手段,对反应过程中各影响因素的研究是氢同位素分离工作中的重要内容。在自行设计的不锈钢催化交换柱中,装填一定体积比的疏水催化剂与亲水填料,进行H-D体系气液催化交换实验。观察反应温度、气液摩尔比、不同原料水氘浓度对传质系数的影响,讨论了气体流速对床层压力降的影响情况。结果表明,不同气液比下,反应温度为45°C时传质系数最高。传质系数随原料水氘浓度(5.05 20.1)×10 3增加而降低,传质系数在0.58 1.17和2.65 3.56随着气液摩尔比而增加,催化交换柱床层压力降随气体流速而增加。研究发现,反应温度、气液摩尔比和氘浓度等因素均会影响氘的传质系数。

规整填料压降研究新进展

综述了文献中关于规整填料压降的计算方法和模型,并对这些模型的理论基础和适用条件做了简要分析和比较。传统规整填料压降模型的来源主要是散堆填料的压降关联式和湿壁塔模型。重点归纳了基于过程基本规律的机理模型,与传统压降模型相比,在通用性、适用范围和准确性等方面都有不同程度的改进。同时指出了有待进一步探索和改进的若干问题。

扰流柱形状对流动换热特性影响的数值研究

运用FLUENTCFD商用软件对装有圆形、准水滴形、椭圆形和水滴形4种扰流柱叉排阵列矩形通道内的流动和换热进行了三维数值模拟,获得了通道内流场、压力场以及局部对流换热系数分布的基本特征,并对扰流柱通道的换热特性和压力损失特性进行了对比分析.计算结果表明:装有水滴形扰流柱阵列矩形通道的压力损失系数分别为前3者的44.1%、70.5%和79.8%,而恒热流壁面的平均对流换热系数相对于前3者而言分别降低了18.5%、12.4%和3.8%,压力损失降低的幅度明显高于强化换热的减弱.水滴形扰流柱是一种具有综合性能、替代常规圆形扰流柱的理想结构.

高效液相色谱法测定氨碘肽滴眼液中5种氨基酸的含量

目的采用HPLC法测定氨碘肽滴眼液中丝氨酸（Ser）、甘氨酸（Gly）、组氨酸（His）、异亮氨酸（Ile）、亮氨酸（Leu）的含量。方法采用Ocean-C18色谱柱（250 mm×4.6 mm,5μm）;流动相A：乙腈-水（4∶1）,流动相B：0.1 mol·L-1乙酸钠-乙腈（97：3）;流速为1.0 mL·min-1;柱温：25℃;检测波长：254 nm;用异硫氰酸苯酯（PITC）作为柱前衍生化试剂,采用柱前衍生HPLC法进行分析。结果各种氨基酸能良好地分离,衍生化试剂对氨基酸分析无干扰;平均回收率在98%～102%,RSD均〈3%。结论该方法简便、准确、可靠,可用于氨碘肽滴眼液中氨基酸含量的检测。

大尺寸CFRP约束混凝土方柱落锤动态冲击试验研究

采用FRP增强的混凝土柱在使用过程中,可能受到轴向冲击荷载作用,但目前这方面的研究基本处于空白.通过对7组21个大尺寸CFRP约束混凝土方柱进行落锤轴向冲击试验,研究倒角半径r对约束柱抗冲击性能的影响.试验获取了锤头冲击力时程曲线、压缩变形时程曲线、FRP表面关键点的应变时程曲线和整个破坏过程的高速影像等信息.试验结果表明,CFRP约束混凝土方柱的破坏是由试件中部倒角位置处的CFRP被拉断所导致的,试件的破坏现象与倒角半径r有关;倒角半径r对约束柱的冲击性能有显著影响,r越大,冲击应力峰值和能量密度也越大;CFRP约束混凝土方柱的动力增大系数（DIF）随倒角半径比r.的增大而减小,基本成线性关系,在1.23-1.82之间.

50mm折流板脉冲萃取柱吹气法测量存留分数

在柱径为50mm的折流板脉冲萃取柱中,首先利用吹气法研究了硝酸水溶液和30%TRPO煤油水溶液体系的单相流时均摩擦压降Δpf特性.实验结果表明当A′ω≠0,且uc=0时,Δpf可以忽略;而当A′ω=0时,Δpf与uc满足Noh模型的线性关系.在Noh模型的基础上,给出了计算A′ω≠0时单相流时均摩擦压降的模型,实验结果与模型预测相一致.在单相流摩擦压降的基础上,又研究了连续相分别为硝酸溶液和30%TRPO煤油溶液体系的两相流时均摩擦压降Δpf特征.实验结果表明:两相流时均摩擦压降Δpf可用于计算分散相存留分数,其近似由连续相所对应的Noh单相流模型求得,并可用于折流板脉冲萃取柱分散相存留分数的确定.