并联多柱色谱研究

研究了并联多柱色谱的柱效，证实并联多柱色谱既可以保证较高的柱效又可以增加柱容量，非常适用于大剂量的制备性分离。研究还试验了不同直径的经典柱色谱的柱效，得知较小柱直径的柱壁效应较严重，柱效偏低。     

高效液相色谱法测定三聚氰胺不同色谱柱的选择

用高效液相色谱法测定乳制品中是否含有三聚氰胺,在色谱柱的选择上,通过对C8柱和混合型强阳离子交换色谱柱进行样品分析比对,实验结果证明：其方法准确性可靠,样品采集时间短,定量准确,精密度高,操作方便,成本低。     

气相色谱法低柱温技术在测定环境样品痕量八氟异丁烯中的应用

研究了色谱柱柱温对柱流失、分离效果的影响，采用低柱温技术显著降低了柱流失造成的背景，有利于痕量组分的分析；低柱温技术还明显提高了色谱柱分离效率，有利于在复杂成分样品中低沸点物质的测定。研究了在测定痕量全氟异丁烯中采用ECD检测器与相匹配的色谱柱问题，发现采用交联聚甲基硅氧烷类色谱柱比较适宜。利用本技术测定废水、环境气体中的痕量全氟异丁烯得到了满意的效果。     

混合C5分离—溶剂抽提过程分析方法研究

本文采用气相色谱法-双色谱柱联用方式,建立了对混合C_5馏分溶剂抽提过程中溶剂萃取单元物料组份含量进行分析的分析方法,优化了HP-Al_2O_3/KCl PLOT色谱柱的色谱分离条件,通过试验研究,探索了色谱柱联用的最佳组合,采用HP-INNOWAX色谱柱和HP-PONA色谱柱双柱联用分析溶剂抽提过程中的塔顶样品,采用HP-INNOWAX色谱柱和HP-Al_2O_3/KCl PLOT色谱柱双柱联用分析溶剂抽提过程中的塔底样品,成功的将溶剂萃取单元物料体系各组份完全分离出来,检测方法简捷、适用,重现性好。为C_5馏分萃取精馏,试验研究提供了一种可行、实用的分析方法。     

尿素生产用CO2气体中各组分的测定

采用气相色谱法，利用时间表切换六通阀，连接PoraPak-Q色谱柱和13X分子筛色谱柱，在较低温度下测量高浓度CO2原料气中N2、Ar等组分的含量。     

毛细管气相色谱柱近年的发展

简要地阐述了近几年毛细管气相色谱柱的发展和特点.GC的色谱柱制柱工艺是一个成熟的技术,所以在制柱工艺方面的研究不够活跃.近年新研究的固定相集中在常温离子液体和各种环糊精的衍生物.20世纪GC毛细管色谱柱柱工艺的研究主要在研究机构和学校中进行,而近几年GC毛细管色谱柱的研究和改进集中在色谱柱厂家进行,并立即成为商品柱.近年GC分析所用的色谱柱大都使用毛细管柱,并趋向于使用商品GC毛细管柱,所使用的商品色谱柱中,最多的是以含5%苯基的聚甲基硅氧烷色谱柱.     

ROSEMOUNT GCX在线色谱变送器的改造

叙述ROSEMOUNT新一代在线色谱变送器GCX在乙烯装置中的应用所存在的问题，分析了柱系统中的样品流量的大小对分析结果的影响，提出了色谱变送器柱分析中的样品流路的具体改造方法。     

如何延高压液相色谱柱的使用寿命

分析了液相色谱柱失效的诸多现象和原因，并论述了极性溶剂冲洗法等一些使色谱柱恢复活性的方法。     

色谱柱的失效分析及老化

长时期使用后的色谱仪,色谱柱失效是不可避免的,经色谱柱失效原因的分析,探讨分批、分步老化色谱柱,恢复色谱柱正常使用;通过柱效和分离度测算,评价色谱柱老化效果,保证仪器正常运行。     

如何延长高压液相色谱柱的使用寿命

分析了液相色谱柱失效的诸多现象和原因，并论述了极性溶剂冲洗法等一些使色谱柱恢复活性的方法。     

Enhancement in gas holdup in bubble columns through use of vibrating internals

Including internals in bubble columns is known to enhance the gas holdup. In this paper, a method to achieve this objective substantially has been proposed via the use of vibrating helical spring internals. Experimental observations on effect of vibrating internals such as vibrating helical springs on gas holdup in bubble columns are presented. Effects of superficial gas velocity, H/D ratio (height of the static liquid to column diameter ratio), volume fraction of helical springs, and thickness of the helical spring wires on hydrodynamics parameters are studied. Increase in gas holdup up to 135% is observed by using vibrating helical spring internals in bubble columns compared to bubble columns without internals. This method offers a simple, cost‐effective, and easy way to enhance gas holdup even at high gas fluxes. It has been reported that this enhancement stems from the fact that the vibrating springs breakup the gas into fine bubbles, which effectively reduces their rise velocity and enhances their average residence time in the liquid column.     

Mixing in mechanically agitated gas-liquid contactors,bubble columns and modified bubble columns

Mixing time measurements were made in 300 and 1000 mm i.d. mechanically agitated contactors with different types of impellers, located at different heights from the bottom of the vessel. Mixing time measurements were also made in 150, 200, 385 and 1000 mm i.d. bubble columns with varying liquid heights. Transient pH measurement and conductivity measurement were used to measure the mixing times. Impeller speed was varied in the range of 3.33–20 r/sec in the case of mechanically agitated contactors and gas superficial velocity was varied in the range of 10–250 mm/sec in bubble columns. Effect of physical properties of the fluid (surface tension, ionic strength, liquid viscosity) and that of the non-Newtonian behavior on mixing time was studied. Mixing time in the presence of drag reducing agents was also investigated.In the range of variables covered in this work mixing time in mechanically agitated contactors and bubble columns was found to be in the range of 4–6Mixing time predictions based on the longest loop length and circulation velocity are made in the presence and absence of a gas for mechanically agitatA procedure is given for the prediction of the critical impeller speed for gas phase dispersion in mechanically agitated contactors.     

纯水-顶空毛细柱气相色谱法分析废气中的甲醇

纯水吸收气体中的甲醇,采用顶空毛细柱气相色谱法进行分析。重点对顶空毛细柱气相色谱法测定甲醇的分析条件进行试验探讨。实验结果表明,采用纯水-顶空毛细柱气相色谱法测定甲醇方法简便,标准曲线具有良好的线性回归,方法的灵敏度、精密度、准确度较高,符合现代仪器的发展趋势。     

Long-term prediction of nonlinear hydrodynamics in bubble columns by using artificial neural networks

An artificial neural network (ANN) model was proposed for the long-term prediction of nonlinear dynamics underlying holdup fluctuations in bubble columns with three different diameters of 200, 400 and 800 mm. Local holdup fluctuations were measured with an optical probe in the bubble columns. The superficial gas velocity was varied in the range of 33–90 mm/s. The time intervals between successive bubbles were extracted from the time series of holdup fluctuations to represent hydrodynamic behaviors in the system and used as training and validation data sets. The effect of data preprocessing as well as the numbers of nodes in input and hidden layers on the ANN training behavior was systematically investigated. The prediction capability of the ANN was evaluated in terms of time-averaged characteristics, power spectra and Lyapunov exponents. It was observed that: the ANN model, which was trained with experimental time series and gas velocity, can be used for the long-term prediction of dynamic characteristics in bubble columns by using random data as the initial input. The results indicate that the trained ANN models have the potential of modeling nonlinear hydrodynamic behaviors in bubble columns.     

基于气泡群相间作用力模型的加压鼓泡塔流体力学模拟

目前,多数文献报道了冷态加压湍动鼓泡塔内流动特征,并且通过实验数据回归相关经验关联式。然而,此类关联式适用范围有限,难以直接外推到工业鼓泡塔反应器条件。因此,在FLUENT平台上建立了基于气泡群相间作用力的、动态二维加压鼓泡塔计算流体力学模型。通过数值模拟考察了操作压力为0.5~2.0 MPa,表观气速为0.20~0.31 m·s^-1,内径0.3 m鼓泡塔内流场特性参数分布,并且与冷态实验数据进行比较。结果表明,采用修正后的气泡群曳力模型、径向力平衡模型以及壁面润滑力模型描述气泡群相间作用力,能够较为准确地反映平均气含率和气含率径向分布随操作压力和表观气速变化的规律。     

Effect of Carbon Dioxide Chemical Absorption on Bubble Diameter and Interfacial Area

The influence of a gas‐liquid chemical reaction on the interfacial area produced in a contactor is analyzed. Two different amines were used to capture carbon dioxide by chemical absorption. The effects of the operation time, the amine used, the concentration interval, and the gas flow rate on typical hydrodynamic parameters used in bubble columns such as the gas holdup and the Sauter mean diameter were investigated. These parameters were used to determine the interfacial area value. Significant influences on the gas‐liquid interfacial area were detected, mainly caused by the reaction rate intensity, the physicochemical properties of the liquid phase, and the gas flow rate fed to the contactor.     

Effect of surface morphology on the flow of entrained fine particles by ascending gas through packed beds

Coarse particles of glass or cokes were packed in vertical columns, 1- and 2-m in height, and fine particles of glass or coke were entrained through the columns by the ascending gas flow. These systems were used as a model to investigate the flow of fine coal particles introduced into a blast furnace. The effects of properties of packed particles, as well as fines, on the static and dynamic holdups of fines were then investigated. The static holdup of fines was strongly affected by the surface roughness of the packed particles, while the dynamic holdup of fines was not. These results suggest that the fine particles are trapped in the form of static holdup in the isolated narrow spaces bounded with packed particles, and that they remain on the surface of the packed particles which are exposed to the gas flow for only a short period of time.     

A structured catalytic bubble column reactor: hydrodynamics and mixing studies

This paper reports the results of a comprehensive experimental study of the hydrodynamics and mixing in two bubble column reactors of 0.1 and 0.24 m in diameter with KATAPAK-S^® as packing material. Total gas hold up and axial dispersion coefficients were measured in the structured bubble columns and the values were compared with experimental results obtained in the same work with empty bubble columns. The results reveal that the gas hold up in structured bubble columns is practically the same as in empty bubble columns when compared at the same superficial gas velocity based on open area available for gas–liquid dispersion. The presence of the structured elements in the bubble column reactor reduces the liquid phase backmixing by one order of magnitude.     

Influence of structured packing on gas holdup in a three-phase bubble column

In this work, the influence of structured packing on gas holdup in gas-liquid-solid dispersions has been studied. The experiments were carried out in an empty column and in column containing structured packing operating under identical conditions. Glass beads and silicon carbide particles were used as the solid material and the volumetric fraction of solids was varied from 0% to around 10%. The liquid viscosity was strongly modified using water, CMC solution and glycerol. The experimental results obtained with both columns were compared with previous results obtained in two-phase bubble columns. The influence of structured packing on the total gas holdup for different superficial gas velocities was found to be similar with and without suspended solids. Therefore, the results obtained in this work were analysed on the basis of correlations derived earlier for gas-liquid dispersions. Excepting the results obtained with glycerol, these correlations can predict the gas holdup of three-phase bubble columns with reasonable accuracy.     

鼓泡塔气液两相流内部流场的流体力学特性

采用计算流体力学CFD软件对鼓泡塔内部4种表观气速下内部流场的流体力学行为进行模拟。分析了鼓泡塔内部整体气含率及轴截面处（X=0）液相速度随时间的变化情况;并且对比了在不同表观气速下局部气含率和液相速度在不同高度处的径向分布情况。模拟结果表明,随着时间的增大,整体气含率增大速度比较快,到达稳定时间,整体气含率不再增大。在同一高度处局部气含率随着表观气速的增大而增大。H/D<3时,液相循环流动表现为单相循环流;当H/D=3时,表现为双循环流,流型较单相复杂。