萃取分离轻重两相Π形管液封设计及优化

工程设计中经常利用П形管液封来将萃取分离器中的轻重两相分离,不合理的П形管液封设计会影响生产的顺利进行。通过对萃取分离器界面液位的准确计算及对轻重两相П形管液封设计原理的剖析,提出了轻重两相П形管液封设计方法及提高操作弹性的优化方式。结果表明:采用迭代计算使轻重两相最高点压力相等的方式,可以准确地求得П形管液封高度;通过降低轻相与重相管道阻力降之差或采用高度可调节的П形管液封,可以使分离器界面液位更稳定;将上述方法应用于项目改造实例,取得了良好效果。     

重锤式浮筒液面计的设计

工艺生产过程中,往往需要测定液体界面。特别在同一设备中,经常装有两种比重不同的液体,采用玻璃管液面计,由于重相液体在下,轻相液体在上面,很容易发生液面计指示假液面的现象(见图1)。在常压容器的条件下,采用浮筒液面计,把浮筒设置在轻相与重相液体的界面处,用绳索、滑轮并配以适当的重锤,标尺,可以作到准确地指示两相界面。对于这种液面计,如何正确设计,进行了如下一些     

晶体生长理论的发展趋势与界面相模型

简要介绍了前人提出的晶体生长理论的要点及其优点与不足之处；在此基础之上提出了晶体生长理论的发展趋势及晶体生长所面临的基本科学总则王码电脑公司软件中心；通过分析研究，作者认为晶体生长过程中，介于晶体相与环境相之间的界面相起着重要的作用；重点论述了界面相中的界面层、吸附层和过渡层与晶体生长的关系。并进一步提出了晶体生长的界面相模型。     

铁相—石膏固相反应动力学初探

在传统硅酸盐水泥熟料组成系统中,引入SO_3(通常以CaSO_4配料)不仅使所形成的水泥熟料矿物组成不同于硅酸盐水泥,同时也影响其矿物的形成机构及相互依存关系。本文用XRD,化学相分离方法,定量地研究了不同条件下铁相与石膏固相反应动力学特征,从而探讨了高铁水泥中主要熟料矿相C_2A_xF_(1-x)真和C_4A_3S的相对形成能力与温度、组成的关系,为进一步改善高铁水泥性能提供了基本思路。     

PS/HDPE共混薄膜体系的相态结构分析

利用共焦显微拉曼深度扫描仪和拉曼Mapping成像技术研究了不同比例PS/HDPE及其以SEBS作为增容剂共混体系的相态结构。当体系未加增容剂时,PS和HDPE发生严重的相分离,相态结构分布不均,相界面清晰。加入增容剂之后,共混体系中分散相以不规整的形状被包裹在连续相里面,两相界面变得较为模糊。这是因为增溶剂能与PS和HDPE都能发生相互作用,从而导致不相容的两相分子在相界面出的渗透能力和分子的扩散能力增强。因此,共混体系的相界面变大,体系的相容性增强。     

异丙醇汽液界面特性的平衡分子动力学模拟

采用OPLS刚性联合原子模型,以异丙醇分子的作用位点为统计对象,对异丙醇的汽液界面特性进行了平衡分子动力学模拟研究。模拟结果表明,随着温度的升高,液相主体密度减小,汽相主体密度增大,汽液界面厚度增大;截断半径和薄片数对汽相主体密度体、液相主体密度及汽液界面厚度的影响不大;随着模拟分子数的增大,汽液界面厚度有所增大。     

二氧化碳汽—液界面特性的分子动力学模拟

采用EPM2二氧化碳分子势能模型,以二氧化碳分子内各原子作为统计对象进行统计计算,探讨温度、薄层切片数及截断半径对其汽—液界面特性参数的影响规律。结果表明,随着截断半径的增大,液相主体密度逐渐增大,汽相主体密度逐渐减小,界面层厚度有所减小;薄层切片数对界面层厚度、液相主体和汽相主体的密度影响不大;随着温度的升高,汽相主体密度增加,液相主体密度降低,汽—液界面厚度增大,界面张力逐渐减小。     

微胶囊与微胶囊技术

介绍了微胶囊、微胶囊的包裹材料的种类选用原则、微胶囊囊芯物的种类。重点介绍微胶囊化技术,主要的制备方法有水相分离法、有机相分离法、复相乳液聚合法、乳液聚合法、界面聚合法,界面沉积法、后面三种方法主要用来制备纳米微胶囊,对微胶囊建立特性进行表征,并对微胶囊的大小、膜厚、微胶囊膜的孔径对微胶囊的扩散笥能的影响进行探讨,预测了微胶囊技术的发展前景／     

旋流气浮萃取器

以针式搅拌器为核心,构造了一种借助旋流将轻相流线、气束依次切割分散,快速挟离,产生相际穿渗,而使界面更新和相分离得以显著协同加速的萃取器。     

锆刚玉材料的微波合成

利用电熔刚玉粉以微波加波加热方法获得了高强度材料，高强度是由刚玉颗粒边界处低共熔体结晶决定的。材料强度大小用放出的热在发生相与吸收相之间的传递速度来测定。     

聚丙烯腈原丝的凝固成形与相分离研究进展

以热力学相图为工具,探讨了聚丙烯睛(PAN)原丝凝固成形过程。从相图中原丝凝固成形的不同途径和相应的织态结构可以知道,原液体系以旋节方式分相是最佳的热力学路径。原丝凝固成形可以看作是浓度致变相分离(CIPS)和热致变相分离(TIPS)两种相分离形式的组合,通过后者得到高性能原丝要容易实现得多。可以根据相图来优化纺丝工艺条件,通过调节凝固浴浓度、纺丝液浓度、初始纺丝温度以及淬火深度.削弱CIPS过程在凝固成形中的作用,使凝固成彤尽可能多的以TIPS方式通过旋节线和双节线的交界处进行,以得到具有理想结构的优质的PAN原丝。     

Characteristics of poly(ether ether ketone) microporous membranes prepared via thermally induced phase separation (TIPS)

The morphology and bulk properties of microporous membranes based on poly (ether ether ketone) (PEEK) have been investigated as a function of initial casting composition and thermal and mechanical processing history. Membranes were prepared via solid—liquid phase separation of miscible blends of PEEK and polyetherimide (PEI), with subsequent extraction of the PEI diluent. Scanning electron microscopy studies revealed a microporous morphology with two distinct pore size scales corresponding to diluent extraction from interfibrillar and interspherulitic regions, respectively. The membrane structure was sensitive to both initial blend composition and crystallization temperature, with the resulting pore size distribution reflecting the kinetics of phase separation. For membranes prepared with lower initial diluent content or at lower crystallization temperatures, mercury intrusion porosimetry indicated a relatively narrow distribution of fine interfibrillar pores, with an average pore size of approximately 0.04 microns. Membranes prepared at higher diluent content or at higher crystallization temperatures displayed a broad pore distribution, with a sizeable population of coarse, interspherulitic pores (0.1 to 1 μm in size). Uniaxial drawing led to a fibrillated network structure with markedly higher water flux characteristics compared to the as-cast membranes. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2347–2355, 1997     

Monte Carlo simulations of phase separation in thin polymer blend films: scaling properties of morphological measures

Surface directed phase separation in thin polymer blend film has been studied with Monte Carlo simulations using a simple model based on reptation method. Time evolution of phase structure was characterized quantitatively by morphological measures (the Minkowski functionals) in addition to the inspection of concentration versus depth profiles. It was shown that the dynamical scaling hypothesis holds for the Minkowski functionals describing morphologies at the early stages of phase separation in thin films. Two time regimes with different scaling exponents (0.25, 0.33) were found for the growth of the characteristic length scale in the system corresponding to various transport mechanisms (diffusion along- and normally to the interface). Fast decrease in the morphological measures observed at the end of phase separation was attributed to the confinement of the thin film.     

Phase dynamics and wetting layer formation mechanisms of pattern-directed phase separation in binary polymer mixture films with asymmetry compositions

Focusing on the binary polymer mixture films under the off-critical condition, the phase dynamics and wetting layer formation mechanisms of pattern-directed phase separation are numerically investigated. The simulated results demonstrate that, for different compositions, the polymer mixtures on the strip patterned surface can exhibit various phase morphologies in the strips of the bulk, which can be used to tailor the microscopic structures of films. The evolutions of these phase structures in the strips of the bulk obey almost the same power law with an exponent of 1/3, i.e., the Lifshitz-Slyozov growth law for the films with various off-critical degrees. It is found that the wetting layer thickness near the patterned surface grows logarithmically at the initial stages, just like the wetting layer formation mechanism of the polymer mixture near the surface with an isotropic potential. This revels that only patterning the surface potential may not change the growth law of the wetting layer. The simulated results also indicate that the diffusion of the component in the direction parallel to the surface originates from the edge of the strips.     

液相催化加氢中催化剂的分离方法

介绍了液相催化加氢中常用的Ni系催化剂和贵金属催化剂的分离方法．指出催化剂分离在整个液相催化加氢工艺中的重要性分离方法的选择应根据催化剂的类型、粒径、密度、使用寿命和体系的不同而考虑。生产实践表明,文中所述的分离方法可对催化剂进行有效分离.     

Alkanol removal from the apolar phase of a two-liquid phase bioconversion system. Part 2: Effect of fermentation medium on batch distillation

In two-liquid phase fermentations organic substrates and/or products are dissolved in an apolar phase while microorganisms are suspended in an aqueous medium. The effect of aqueous phase contaminants in the apolar phase on the separation of products from the apolar phase by batch distillation is described in this paper. Various amounts of polar phase, emulsified apolar phase and microorganisms normally present in the two-liquid fermentation medium were added to the organic phase. The recovery performance of a distillation unit in separating 1-octanol from such contaminated apolar phases was determined. Further, the bulk properties of the emulsified apolar phase, such as its composition, the nature and the stability of the emulsion were analysed. It was found that the distillation performance is very sensitive to the presence of fermentation media in the organic phase. The energy cost per kg product recovered was almost doubled for only small additions of fermentation impurities. The emulsified apolar phase was shown to be kinetically, but not thermally, stable. Based on these results a suitable apolar phase separation process before distillation can be developed, taking into account energy costs for phase separation and subsequent distillation, to optimize the overall downstream product purification process. © 1998 SCI     

Optimization of structure and properties of polyphenylene sulfide porous membrane by controlling the process of thermally induced phase separation

Polyphenylene sulfide (PPS) porous membranes were successfully prepared from miscible blends of PPS and polyethersulfone (PES) via thermally induced phase separation followed by subsequent extraction of the PES diluent. The morphologies, crystalline structures, mechanical properties, pore structures and permeate fluxes of the PPS porous membranes obtained from different phase separation processes were characterized and are discussed. During the phase separation in the heating process, PPS and PES mainly underwent liquid–liquid phase separation, and then a nonhomogeneous porous structure with a mean pore size of 100 μm and a honeycomb‐like internal structure formed on the membrane surface. The phase separation of PPS/PES occurring in the cooling process was easier to control and the related pore diameter distribution was more regular. In the process of direct annealing, as the phase separation temperature decreased, the pore size distribution became more homogeneous and the mean diameter of the pores also decreased gradually. When the phase separation temperature decreased to 200 °C, PPS membranes with a network structure and a uniform as well as well‐interconnected porous structure could be obtained. In addition, the maximum permeation flux reached 1718.03 L m^–2 h^–1 when the phase separation temperature was 230 °C. The most probable pore diameter was 6.665 nm, and the permeate flux of this membrane was 2.00 L m^–2 h^–1; its tensile strength was 17.07 MPa. Finally, these PPS porous membranes with controllable pore structure as well as size can be widely used in the chemical industry and energy field for liquid purification. © 2020 Society of Chemical Industry     

多组元溶液分相条件的探讨

本文通过改型的UNIQUAC方程 ,利用NEWTON RAPHSON法计算了二元、三元及四元液液平衡数据。从中发现 ,当具有部分互溶性质组分的活度系数发生突变时 ,则该体系就会出现分层现象。为此 ,本文认为具有部分互溶组分活度系数的突变可做为多组元溶液分相的判据。     

Aqueous Foam Stabilized by Hydrophobic SiO2 Nanoparticles using Mixed Anionic Surfactant Systems under High-Salinity Brine Condition

A primary concern of surfactant-assisted foams in enhanced oil recovery (EOR) is the stability of the foams. In recent studies, foam stability has been successfully improved by the use of nanoparticles (NP). The adhesion energy of the NP is larger than the adsorbed surfactant molecules at the air–water interface, leading to a steric barrier to mitigate foam-film ruptures and liquid-foam coalescence. In this study, the partially hydrophobic SiO₂ nanoparticles (SiO₂-NP) were introduced to anionic mixed-surfactant systems to investigate their potential for improving the foamability and stability. An appropriate ratio of internal olefin sulfonate (C_15-18 IOS) and sodium polyethylene glycol monohexadecyl ether sulfate (C₃₂H₆₆Na₂O₅S) was selected to avoid the formation of undesirable effects such as precipitation and phase separation under high-salt conditions. The effects of the NP-stabilized foams were investigated through a static foam column experiment. The surface tension, zeta potential, bubble size, and bubble size distribution were observed. The stability of the static foam in a column test was evaluated by co-injecting the NP-surfactant mixture with air gas. The results indicate that the foam stability depends on the dispersion of NP in the bulk phase and at the water–air interface. A correlation was observed in the NP-stabilized foam that stability increased with increasing negative zeta potential values (−54.2 mv). This result also corresponds to the smallest bubble size (214 μm in diameter) and uniform size distribution pattern. The findings from this study provide insights into the viability of creating NP-surfactant interactions in surfactant-stabilized foams for oil field applications.     

赤藓糖醇微观固液相变及热传导的分子动力学研究

采用分子动力学方法对微尺度下赤藓糖醇的固液相变及热传导现象进行了模拟研究。首先选用GROMOS力场计算了赤藓糖醇固液两相的密度并将预测结果与实测值进行对比,验证了该力场的适用性。采用界面/NPT法模拟了赤藓糖醇的微观熔化过程,通过体系的体积突变得到预测熔点约为400 K,和实测值（392±1） K较为吻合。与直接加热纯固态赤藓糖醇的方法相比,该方法由于引入固液界面降低了成核自由能位垒,使得微观熔化过程的模拟更准确。此外,基于非平衡分子动力学方法研究了赤藓糖醇分子间的微观热传导现象。模拟得到液态赤藓糖醇的热导率为0.33～0.35 Wm^-1K^-1,与宏观实测值（0.33±0.02） Wm^-1K^-1保持一致。因为处于液态时赤藓糖醇的分子分布具有无序性,所以其热导率预测值几乎不随模拟系统的尺寸而变化。