A novel constant interfacial area cell for determining the extraction kinetics of Er(Ⅲ) from chloride medium

A novel constant interfacial area cell(NCIAC),by spatially separating the agitation from liquid flow circulation of organic and aqueous two phases,was suggested to obtain detailed kinetic data for Er(Ⅲ) extraction from chloride medium by 2-ethyl-hexyl-phosphonic acid mono-(2-ethylhexyl) ester(EHEHPA).Different from the traditional Lewis cell and the constant interfacial area cell with laminar flow,the concentrations of Er(Ⅲ) in organic and aqueous two phases were uniform,and the stability of the interfacial area between the two phases could be controlled effectively.Therefore,the special requirements for the design of agitators in the traditional Lewis cell and the constant interfacial area cell for minimizing the influence of diffusion resistance could be avoided.Experimental results indicated that the extraction kinetics was mainly affected by the aqueous flow rate,interfacial area between organic and aqueous two phases,and the aqueous p H values.An extraction kinetic equation was suggested based on the experimental data.

Degradation of Microcystin-LR by Gas-Liquid Interfacial Discharge Plasma

In this study, we report on the degradation of microcystin-LR （MC-LR） by gas- liquid interracial discharge plasma. The influences of operation parameters such as average input voltage, electrode distance and gas flow rate are investigated. Experimental results indicate that the input voltage and gas flow rate have positive influences on MC-LR degradation, while the electrode distance has a negative one. After 6 min discharge with 25 kV average input voltage and 60 L/h air aerati by discharge both in on, the degradation rate of MC-LR achieves 75.3%. distilled water and MC-LR solution are measured H202 and 03 generated Moreover, an emission spectroscopy is used as an indicator of the processes that take place on the gas-liquid boundary and inside plasma. Varied types of radicals （O, .OH, CO, 03, etc.） are proved to be present in the gas phase during gas-liquid interfacial discharge.

Measurement and Prediction of Interfacial Area on a DistiIlation Tray

In this paper the modern electron optical equipment is used to translate the clear image of speed moving bubbles in bubbling liquid on a sieve tray into the digital information stored in computer, and the computer aided image processing technique is utilized to measure the bubble size distributions and interfacial areas under various operating conditions. And the dynamic behavior of bubbles in turbulent liquid is analyzed theoretically; the mechanism of bubble deformation and breakage is explored on the basis of Kolmogoroff′s isotropic turbulence hypothesis; the mathematical model for predicting the gas liquid interfacial area is proposed. The comparison between the simulated results and the experimental data shows that the model is higher in accuracy, simple in form and convenient in use.

Numerical investigation on characteristics of interfacial wave of liquid film in gas-liquid two-phase flow using OpenFOAM

Liquid film cooling as an advanced cooling technology is widely used in space vehicles.Stable operation of liquid film along the rocket combustion inner wall is crucial for thermal protection of rocket engines.The stability of liquid film is mainly determined by the characteristics of interfacial wave,which is rarely investigated right now.How to improve the stability of thin film has become a hot spot.In view of this,an advanced model based on the conventional Volume of Fluid(VOF)model is adopted to investigate the characteristics of interfacial wave in gas-liquid flow by using OpenFOAM,and the mechanism of formation and development of wave is revealed intuitively through numerical study.The effects from gas velocity,surface tension and dynamic viscosity of liquid(three factors)on the wave are studied respectively.It can be found that the gas velocity is critical to the formation and development of wave,and four modes of droplets generation are illustrated in this paper.Besides,a gas vortex near the gas-liquid interface can induce formation of wave easily,so changing the gas vortex state can regulate formation and development of wave.What’s more,the change rules of three factors influencing on the interfacial wave are obtained,and the surface tension has a negative effect on the formation and development of wave only when the surface tension coefficient is above the critical value,whereas the dynamic viscosity has a positive effect in this process.Lastly,the maximum height and maximum slope angle of wave will level off as the gas velocity increases.Meanwhile,the maximum slope angle of wave is usually no more than 38°,no matter what happens to the three factors.

Stability of Stratified Gas-Liquid Flow in Horizontal and Near Horizontal Pipes

A viscous Kelvin-Helmholtz criterion of the interfacial wave instability is proposed in this paper based on the linear stability analysis of a transient one-dimensional two-fluid model. In thismodel, the pressure is evaluated using the local momentum balance rather than the hydrostatic approximation. The criterion predicts well the stability limit of stratified flow in horizontal and nearly horizontal pipes. The experimental and theoretical investigation on the effect of pipe inclination on the interfacial instability are carded out. It is found that the critical liquid height at the onset of interfacial wave instability is insensitive to the pipe inclination. However, the pipe inclination significantly affects critical superficial liquid velocity and wave velocity especially lor low gas velocities.

A Hydrodynamic Modei for Slug Frequency in Horizontal Gas-Liquid Two-Phase Flow

The prediction of slug frequency has important significance on gas-liquid two-phase flow. A hydrody-namic modei was put forward to evaluate slug frequency for horizontal two-phase flow, based on the dependence of slug frequency on the frequency of unstable interfacial wave. Using air and water, experimental verification of the modei was carried out in a large range of flow parameters. Six electrical probes were installed at different positions of a horizontal plexiglass pipe to detect slug frequency development. The pipe is 30m long and its inner diameter is 24 mm. It is observed experimentally that the interfacial wave frequency at the inlet is about l to 3 times the frequency of stable slug. The slug frequencies predicted by the modei fit well with Tronconi (1990) modei and the experimental data. The combination of the hydrodynamic modei and the experimental data results in a conclusion that the frequency of equilibrium liquid slug is approximately half the miniraum frequency of interfacial wave.

Measurements of the effective mass transfer areas for the gas–liquid rotating packed bed

Rotating packed bed(RPB) is one of the most effective gas–liquid mass transfer enhancement reactors, its effective specific mass transfer area(ae) is critical to understand the mass transfer process. By using the NaOH–CO_(2) chemical absorption method, the aevalues of three RPB reactors with different rotor sizes were measured under different operation conditions. The results showed that the high gravity factor and liquid flow rate were major affecting factors, while the gas flow rate exhibited minor influence.The radius of packing is the dominant equipment factor to affect aevalue. The results indicated that the contact area depends on the dispersion of the liquid phase, thus the centrifugal force of rotating packed bed greatly influenced the aevalue. Moreover, the measured ae/ap(effective specific mass transfer area/specific surface area of packing) values were fitted with dimensionless correlation formulas. The unified correlation formula with dimensionless bed size parameter can well predict the experimental data and the prediction errors were within 15%.

基于可解释性神经网络的界面面积浓度预测

界面面积浓度(Interfacial Area Concentration,IAC)是两相流动的封闭两流体模型中界面传递项的关键参数,用于表征气液界面传输能力的强弱。对界面面积浓度的建模预测通常有经验关联式和界面面积输运方程等方法,但这些方法都有较大的数据依赖性。而对神经网络模型增添可解释性可以为模型修正提供方向,严谨提升预测精度。为更好地预测两相流动的IAC,基于神经网络建立了IAC的预测模型,结合不同气泡行为、物理关系及统计分布并利用事后可解释性方法,对比分析了不同输入特征组合的神经网络模型预测能力;并通过神经网络每层的结构参数大小,分析输出比重挑选合适的数据预处理方法。通过事后可解释性分析得到空泡份额是IAC预测的重要因素,而对训练数据进行对数变换预处理能够显著提高模型对真实数据的预测能力。

Simulation of interfacial Marangoni convection in gas-liquid mass transfer by lattice Boltzmann method

Interfacial Marangoni convection has signifi-cant effect on gas-liquid and/or liquid-liquid mass transfer processes.In this paper,an approach based on lattice Boltzmann method is established and two perturbation models,fixed perturbation model and self-renewable interface model,are proposed for the simulation of interfacial Marangoni convection in gas-liquid mass transfer process.The simulation results show that the concentration contours are well consistent with the typical roll cell convection patterns obtained experimentally in previous studies.

Efficient organic-inorganic hybrid cathode interfacial layer enabled by polymeric dopant and its application in large-area polymer solar cells

An organic-inorganic hybrid cathode interfacial layer(CIL) was developed by doping ZnO with the naphthalene-diimide based derivative NDI-PFNBr. It was found the resulting organic-inorganic hybrid CIL showed apparently improved conductivity and could act as an effective cathode interlayer to modify indium tin oxide(ITO) transparent electrodes. As a result, by employing the blend of PTB7-Th:PC71BM as the photoactive layer, the inverted polymer solar cells(PSCs) exhibited a remarkable enhancement of power conversion efficiency(PCE) from 8.52% for the control device to 10.04% for the device fabricated with the hybrid CIL. Moreover, all device parameters were simultaneously improved by using this hybrid CIL. The improved open-circuit voltage(VOC) was attributed to the reduced work function of the ITO cathode, whereas the enhancements in fill factor(FF) and short-circuit current density(JSC) were assigned to the increased conductivity and more effective charge extraction and collection at interface. Encouragingly, when the thickness of the hybrid CIL was increased to 80 nm, the resulting device could still keep a PCE of 8.81%, exhibiting less thickness dependence. Considering these advantages, 16 and 93 cm2large-area PSCs modules were successfully fabricated from the hybrid CIL by using doctor-blade coating techniques and yielded a remarkable PCE of8.05% and 4.49%, respectively. These results indicated that the hybrid CIL could be a promising candidate to serve as the cathode interlayer for high-performance large-area inverted PSCs.

棒束子通道空泡份额及相界面浓度分布特性实验研究

棒束通道相态分布特性对反应堆内传热传质及流动阻力具有重要影响。本文对5×5棒束通道空气水两相流开展实验研究,采用四头电导探针测量了子通道内部的空泡份额、相界面浓度、气泡直径、气泡速度等相界面参数的局部分布。结果表明,气泡受横向作用力的影响,在子通道内会形成两种典型分布,随液相流速升高和气相流速降低,轴峰分布逐渐转变为壁峰分布;不同类型子通道空泡分布不均匀,中心子通道受壁面影响较小,气泡数量最多,边通道和角通道几乎被液相占据;本实验工况下,现有的空泡份额和相界面浓度计算关系式预测性能良好,平均最小误差分别为±18.2%与±12.2%。

The Behavior and Characteristics of the InterfacialWaves in Gas-Liquid Two-Phase Separated FlowThrough Downward Inclined Rectangular Channel

An experimental investigation on the behavior and characteristics of interfacial waves in downward inclined rectangular channel was conducted. The interfacial waves were traced and measured by us-ing conductance technique. The wav patterns were distinguished and defined. The characteristics of the interfacial waves, such as time-averaged film thickness, wave height, wave propagation speed,wavlength and wave frequency, were systematically examined in terms of gas and liquid superficial volumetric fiuxes. The effect of the inclination and flow channel geometry of the test section on the interfacial wav was also investigated.

Kinetics of cerium(Ⅳ) and fluoride extraction from sulfuric solutions using bifunctional ionic liquid extractant(Bif-ILE)[A336][P204]

The extraction kinetics of Ce（Ⅳ） and Ce（Ⅳ）-F^- mixture systems from sulfuric solutions to n-heptane solution containing Bif-ILE[A336][P204]（[trialkylmethylammonium][di-2-ethylhewanxylphosphinate]） with a constant interfacial area cell with laminar flow were studied,just to elucidate the extraction mechanism and the mass transfer models.The data were analyzed in terms of pseudo-first-order constants.The effects of stirring speed,specific interfacial area and temperature on the extraction rate in both systems were discussed,suggesting that the extractions were mixed bulk phases-interfacial control process.Supported by the experimental data,the corresponding rate equations for Ce（Ⅳ） extraction system and Ce（Ⅳ）-F^- mixture extraction system were obtained.The experimental results indicated the rate-controlling step.The kinetics model was deduced from the rate-controlling step and consistent with the rate equation.

相间交界面对非饱和土应力状态的影响

非饱和土是一种三相多孔介质,不同相之间的交界面尤其是气液交界面的存在直接影响了非饱和土的宏观行为.首先对土中交界面的形式和作用进行了探讨,指出气液交界面对非饱和土的行为有重要影响,并给出了界面功和气液比表面积的表达式.在已有的非饱和土变形功表达式基础上,引入界面能影响,得到了考虑交界面影响的非饱和土自由能方程.利用所得的自由能方程,给出了考虑交界面影响的非饱和土固相和液相相应的应力变量.对考虑交界面面积的液相流动方程进行了探讨,给出了非平衡条件下的土水特征曲线表达式,指出在平衡条件下土水特征曲线中应当考虑交界面面积的影响,传统土水特征曲线是三维关系在吸力-饱和度平面上的投影.将比表面积与土水特征曲线的关系,利用已有试验数据验证了该表达式的合理性.利用界面面积的表达式计算有效应力,将其与已有试验结果进行对比,表明给出的比表面积表达式可很好地反映实际情况.不同于已有现象学研究,本文推导具有严格的理论基础,研究表明完整的有效应力表达式中应考虑土体内部作用力的影响,其不仅包含基质吸力,同时还包含其他形式的作用力,其大小与界面比表面积有关.该表达式为下一步研究界面效应对土体变形、强度和流动特性的研究提供了基础.

水力喷射-空气旋流器用于湿法烟气脱硫及其传质机理

在一种新型高效的气液传质设备——水力喷射-空气旋流器（WSA）中,以Ca（OH）2料浆为吸收剂进行了模拟烟气湿法脱硫的实验研究。结果表明：脱硫率随进口气速增加而增加;随液体喷射速度增加先增加,增加到一定程度后几乎不变;随烟气中SO2的进口浓度增加而减小,存在一适宜的Ca（OH）2浓度和回流比。在气体流量24～72 m3·h-1、循环液体量0.4～0.8 m3·h-1、料浆中Ca（OH）2浓度7500 g·m-3时,对SO2浓度为1891～6373 mg·m-3的烟气进行湿法脱硫,脱硫率达88.9%～97.7%,且WSA的旋流气体和喷射液体在湿法脱硫中具有自清洁能力,未发现内部结垢和喷孔堵塞现象。总体积传质系数KGa、有效相界面积a均随进口气速uG增大而增大,而总传质系数KG随uG增加变化较小;当液体喷射速度 uL≤0.26 m·s-1时,KGa和KG随uL增加快速增大,之后增加缓慢,而a随uL几乎线性增加,KGa和KG随吸收剂中Ca（OH）2浓度cL增加有一最大值。结合实验数据拟合得到了相关的经验公式,这些关联式能较好地预测WSA的湿法脱硫传质性能。气体旋流场强度对总体积传质系数KGa和有效相界面积a起支配作用,脱硫传质过程同时受气膜和液膜阻力控制,但以液膜控制为主。

化学吸收法测定旋转填料床有效相界面积

用化学吸收法测量了同心环波纹碟片旋转填料床在气液两相沿径向逆流条件下有效相界表面积及有效比相界表面积．实验结果表明，同心环波纹碟片旋转填料床不仅可１００％地有效利用填料自身的表面积，而且可起到良好的雾化扩展相界面积的作用，使相界面积增加２～３．５倍．

PAFC空气电极催化层相界面结构分析

提出一个考虑了催化层中电压不均匀分布，可以在任意气体压力ｐ、输出电流密度Ｉ工作条件下，表征ＰＡＦＣ空气电极行为的数学模型．发现表征“气／液”相界面比表面的参数ＡＢ与Ｉ在不同的ｐ下呈不同的线性关系．其中在较低的压力下ＡＢ对Ｉ有较深的依赖关系，而在较高的压力ｐ下，ＡＢ趋向与Ｉ无关．表征“液／固”界面的参数ＡＩ在不同ｐ、Ｉ下基本保持不变．利用所构建的数学模型对ＰＡＦＣ空气电极中催化反应层内Ｏ２电化学还原速率进行了定量分析．结果表明，大电流下运行的空气电极，其主要的电极反应发生在“扩散层／催化层”交界处的催化反应层中，意味着厚的催化反应层是不必要的．

川渝地区含硫气井固井水泥环界面腐蚀机理分析

酸性气井井下防腐是石油工程学界的技术难题之一,对于"井筒第一屏障"——固井水泥环的腐蚀研究更是备受重视。针对目前井下固井水泥环腐蚀研究中存在的问题,采用界面腐蚀的试验方法,利用X射线衍射、扫描电镜等实验分析手段,对川渝地区含硫气井固井水泥环腐蚀机理进行了探索。结果表明:①水泥石的腐蚀深度和H2S分压值、腐蚀时间成正比;②腐蚀后水泥石抗压强度值和H2S分压值、腐蚀时间成反比;③由于水泥石受酸性气体腐蚀后的产物逐渐富集、堆积及运移,使水泥石形成一个较为稳定的致密层或腐蚀过渡带,腐蚀后水泥石的孔隙度和渗透率随腐蚀时间的增加呈现先增加后降低的特点,并最终使腐蚀介质进入水泥石内部变得更加困难;④确保水泥环在保持一定腐蚀深度的情况下,尽快形成较为稳定的腐蚀过渡带或降低水泥环的腐蚀速率,是含硫气井固井水泥环在酸性环境下保持长期密封性及化学完整性的重要基础条件。

侧吹炼铜过程中乳化现象的模拟

为定量描述熔炼过程中乳化现象,首先建立了基于相似原理的物理模型,然后使用高分辨率相机和Image Pro-Plus 6.0软件考察了气体流量对熔池内乳化层的形成、乳化液滴尺寸分布的影响规律,最终建立了传质界面面积ɑ的估算方法.结果表明:乳化液滴的体积表面积平均直径值(SMD)随着气体流量的增大而减小,乳化层内ɑ值随着气体流量的增大几乎呈线性增长,铜锍与渣的分离可由重力和扩散传质引起.

双探针测量气液界面密度的研究

推广了原有气液两用流局部界面密度双探针方法测量模型，使这一模型不仅可用于球形界面，而且可用于各种长、短轴半径之比的椭圆形扁球体界面型式的气液分散流动。基于改进的测量模型，应用光导纤维双探针技术测量了垂直圆管内气液两相泡状流的界面密度。测量结果与照相方法所测结果符合良好。