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SCI和EI收录∣中国化工学会会刊
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Table of Content
28 April 2002, Volume 10 Issue 2
    RESEARCH PAPERS
    Study on High-Speed Centrifugal-Regenerative Pump with an Inducer
    ZHU Zuchao, CHEN Ying, JIN Qingming, HUANG Dunhui
    2002, 10(2):  137-141.  doi:
    Abstract ( )   PDF (1373KB) ( )  
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    The study on high-speed centrifugal-regenerative pumps with an inducer (HCRP) is carried
    out. Thecombined structure of inducer, centrifugal impeller, and regenerative impeller is
    presented, and a theoretical parallelcombinatorial hydraulic design method is investigated.
    The comparative experimental results show that efficiency insmaller capacity region, head
    coefficient and efficiency in larger capacity region of HCRPs is few lower, much higherand
    lower than those of high-speed centrifugal pumps, respectively, anci that the suction
    performance of HCRPs isdetermined only by inducer. HCRPs can be more suitably applied to
    deliver small-capacity high-head liquids inchemical and petrochemical industries.
    Comparison of a Full Second-Order Moment Model and an Algebraic Stress Two-Phase Turbulence
    Model for Simulating Bubble-Liquid Flows in a Bubble Column
    ZHOU Lixing, YANG Min, LIAN Chnying, L. S. Fan, D. J. Lee
    2002, 10(2):  142-148.  doi:
    Abstract ( )   PDF (2002KB) ( )  
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    A full second-order moment (FSM) model and an algebraic stress (ASM) two-phase turbulence
    modelare proposed and applied to predict turbulent bubble-liquid flows in a 2D rectangular
    bubble column. Predictiongives the bubble and liquid velocities, bubble volume fraction,
    bubble and liquid Reynolds stresses and bubble-liquidvelocity correlation. For predicted
    two-phase velocities and bubble volume fraction there is only slight differencebetween
    these two models, and the simulation results using both two models are in good agreement
    with the particleimage velocimetry (PIV) measurements. Although the predicted two-phase
    Reynolds stresses using the FSM are insomewhat better agreement with the PIV measurements
    than those predicted using the ASM, the Reynolds stressespredicted using both two models
    are in general agreement with the experiments. Therefore, it is suggested to usethe ASM
    two-phase turbulence model in engineering application for saving the computation time.
    Numerical Simulation of Viscous Flow Through Spherical Particle Assemblage with the
    Modified Cell Model
    MAO Zaisha
    2002, 10(2):  149-162.  doi:
    Abstract ( )   PDF (4045KB) ( )  
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    The cell model developed since 1950s is a useful tool for exploring the behavior of
    particle assemblages,but it demands further careful development of the outer cell boundary
    conditions so that interaction in a particleswarm is better represented. In this paper, the
    cell model and its development were reviewed, and the modificationsof outer cell boundary
    conditions were suggested. At the cell outer boundary, the restriction of uniform liquid
    flowwas removed in our simulation conducted in the reference frame fixed with the particle.
    Zero shear stress conditionwas used to evaluate the outer boundary value of the stream
    function. Boundary vorticity was allowed to evolve tovalues compatible to existing stream
    function at the free shear outer boundary. The fore-aft symmetry of vorticitydistribution
    at the outer boundary is thought critical to ensure the continuity of inflow and outflow
    between touchingneighbor cells, and is also tested in the modified cell model. Numerical
    simulation in terms of stream function andvorticity based on the modified cell models was
    carried out to shed light on the interaction between liquid andparticles. Lower predicted
    drag coefficient by the modified cell models was interpreted with the feature of
    flowstructure. The drag coefficient from the simulation was also compared with correlations
    of drag coefficient reportedin literature. It is found that the modified cell model with
    the uniformity of external flow relaxed and the fore-aftsymmetry of boundary vorticity
    enforced was the most satisfactory on the overall performance of prediction.
    Velocity Slip and Interfacial Momentum Transfer in the Transient Section of Supersonic Gas
    -Droplet Two-Phase Flows
    WEIWenyun, ZHU Jiahua, XIA Sulan, DAI Guangqing, GAO Xudong
    2002, 10(2):  163-169.  doi:
    Abstract ( )   PDF (1974KB) ( )  
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    Modelling and simulations are conducted on velocity slip and interfacial momentum transfer
    for super-sonic two-phase (gas-droplet) flow in the transient section inside and outside a
    Laval jet(L J). The initial velocity slipbetween gas and droplets causes an interfacial
    momentum transfer flux as high as (2.0-5.0) × 104 Pa. The relaxationtime corresponding to
    this transient process is in the range of 0.015-0.090 ms for the two-phase flow formed
    insidethe LJ and less than 0.5 ms outside the LJ. It demonstrates the unique performance of
    this system for application tofast chemical reactions using electrically active media with
    a lifetime in the order of 1 ms. Through the simulationsof the transient processes with
    initial Mach number Mg from 2.783 to 4.194 at different axial positions inside theLJ. it is
    found that Mg has the strongest effect on the process. The momentum flux increases as the
    Mach numberdecreases. Due to compression by the shock wave at the end of the L J, the flow
    pattern becomes two dimensionaland viscous outside the LJ. Laser Doppler velocimeter (LDV)
    measurements of droplet velocities outside the LJ arein reasonably good agreement with the
    results of the simulation.
    A Sedimentation-Dispersion Model for both Non-attached and Attached Particles in Three-
    Phase Batchwise Fluidized Beds
    ZHANG Jiyu, LIN Cheng, LIN Chunshen
    2002, 10(2):  170-176.  doi:
    Abstract ( )   PDF (2233KB) ( )  
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    The axial concentration distribution of both particles with better wetting (forming non-
    attached system)and poorer wetting (forming attached system) was investigated in a vertical
    gas-liquid-solid fluidized bed of 4.2 cm indiameter and 130 cm in height with the solids
    holdup less than 0.05. The one-dimensional sedimentation-dispersionmodel could be used
    satisfactorily to describe the axial distribution of solids holdup by modifying only a
    modelparameter, i.e. by means of the terminal settling velocity minus a certain value,
    which is a function of gas velocityand considers the effect of an additional drag force
    resulted from attached rising bubbles. The axial profiles of solidconcentration predicted
    are in good agreement with experimental results. This model also explains reasonably
    thedifferent axial distributions of solid concentration, i.e. the solids holdup decreases
    as the axial height increases innon-attached system, but increases with the axial height in
    attached system at a given gas velocity.
    Mass Spectrometric Studies of Selective Oxidation of n-Butane over a Vanadium Phosphorus
    Oxide Catalyst
    CHEN Biaohua, HUANG Xiaofeng, LI Chengyue, LIANG Rizhong, ZHAO Bangrong
    2002, 10(2):  177-182.  doi:
    Abstract ( )   PDF (2319KB) ( )  
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    The selective oxidation of n-butane to maleic anhydride (MA) on a vanadium-phosphorus oxide
    (VPO)catalyst was studied using on-line gas-chromatography combined with mass spectrometry
    (GC-MS) and transientresponse technique. The reaction intermediates, butene and furan, were
    found in the reaction effluent under nearindustrial feed condition (3% butane+15%O2), while
    dihydrofuran was detected at high butane concentration (12%butane, 5%O2). Some
    intermediates of MA decomposition were also identified. Detection of these
    intermediatesshows that the vanadium phosphorus oxides are able to dehydrogenate butane to
    butene, and butene further to formMA. Based on these observations, a modified scheme of
    reaction network is proposed. The transient experimentsshow that butane in the gas phase
    may directly react with oxygen both on the surface and from the metal oxidelattice, without
    a proceeding adsorption step. Gas phase oxygen can be adsorbed and transformed to surface
    latticeoxygen but it can not participate in selective oxidation. Adsorbed oxygen leads to
    deep oxidation, while latticeoxygen leads to selective oxidation.
    Theoretical Predictions of Migration Probabilities of Liquid- Liquid Hydrocyclones Separating Light Dispersions
    ZHAO Qingguo, MA Chongfang
    2002, 10(2):  183-189.  doi:
    Abstract ( )   PDF (2063KB) ( )  
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    Based on Bloor & Ingham’s approach for determining the fluid field and on the analyses of loci offluid particles inside hydrocyclones, analytical models are developed for calculating the migration probability ofsingle-cone and two-cone hydrocyclones separating light dispersions. The calculated results are in good agreementwith Thew’s correlation at different flow rate, split ratio or fluid properties if the structural parameters keep thesame as those of Thew’s 35 mm hydrocyclone. The difference between predictions according to two-cone model andsingle-cone model is nearly negligible, which is very close to Thew’s original idea that major separation happensin the small cone-angle zone. Calculated results indicate that split ratio has little effects on reduced migrationprobability at least for F ≤ 20%, which is consistent to the conclusion drawn from Thew’s correlation that reducedmigration probability will remain constant when split ratio changes. Because no simplifying hypothesis is imposed onstructural parameters, the presented models can also be reliably applied in predicting the effects of those parameterson migration probability.
    Effects of PAA and PBTCA on CaCO3 Scaling in Pool Boiling System
    YANG Qingfeng, GU Anzhong, DING Jie, SHEN Ziqiu
    2002, 10(2):  190-197.  doi:
    Abstract ( )   PDF (1259KB) ( )  
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    Formation of mineral scales on heat exchangers is a persistent and expensive problem. In
    the presentpaper, the calcium carbonate scale inhibition by two inhibitors, polyacrylic
    acid (PAA) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) has been studied in a
    pool boiling system. It is found that PBTCA has abetter inhibition effect than PAA under
    the identical conditions. X-ray diffraction(XRD) and Fourier transform-infrared(FTIR)
    analyses demonstrate that the content of vaterite increases as inhibition effects increase.
    Themetastable crystal forms of vaterite and aragonite are stabilized kinetically in the
    presence of inhibitors. Therelationship between the inhibition effect and the fractal
    dimension has also been investigated. The result showsthat the fractal dimension is higher
    in the presence of inhibitors. The better the inhibition effect, the higher thefractal
    dimension. The step morphology was observed by atomic force microscopy (AFM) images. It is
    shown thatthe step space on the calcium carbonate surface increases in the presence of
    inhibitors. Moreover, with the increaseof inhibition effect, both the step space and the
    fractal dimension increase. The step bunching is found on thecalcium carbonate by AFM. The
    better the inhibition effect of the inhibitor, the slower the step velocity in theunbunched
    location. As a result, the step space becomes wider in the presence of PBTCA than that in
    the presenceof PAA.
    Simulation and Off-line Optimization of an Acrylonitrile Fluidized-bed Reactor Based on
    Artificial Neural Network
    LI Wei, ZHANG shuwei, LI Yan, ZHANG Peicun, WANG Xiaodou
    2002, 10(2):  198-201.  doi:
    Abstract ( )   PDF (1350KB) ( )  
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    A mathematical model is developed for an industrial acrylonitrile fluidized-bed reactor
    based on arti-ficial neural networks. A new algorithm, which combines the characteristics
    of both genetic algorithm (GA) andgeneralized delta-rule (GDR) is used to train artificial
    neural network (ANN) in order to avoid search terminatedat a local optimal solution. For
    searching the global optimum, a new algorithm called SM-GA, incorporating ad-vantages of
    both simplex method (SM)and GA, is proposed and applied to optimize the operating
    conditions of anacrylonitrile fluidized-bed reactor in industry.
    Analyses of Multiplicity and Stability Patterns of Agglomer- ation Controlled Precipitation
    with Both Primary and Secondary Nucleations
    YIN Qiuxiang, ZHANG Meijing, WANG Jingkang
    2002, 10(2):  202-207.  doi:
    Abstract ( )   PDF (2027KB) ( )  
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    The possibility of multiplicity in an isothermal continuous mixed suspension-mixed product
    removalcrystallizer is explored using the bifurcation theory. A process involving
    agglomeration controlled precipitationis considered in which secondary nucleation occurs
    simultaneously with primary nucleation. The determinantequations for the existence of
    multiple steady states are developed and the multiplicity boundaries dependent on
    thephysical and kinetic properties and operational parameters of the process are obtained
    by resolving these determinantequations. The number of steady states in the precipitator
    for various multiplicity regions is determined and thelinear stability of these steady
    states is analyzed by using the Routh criterion.
    A New Method of Crystallization of Octahydro Trisodium Salt of Fructose-1,6-diphosphate
    YING Hanjie, OUYANG Pingkai
    2002, 10(2):  208-211.  doi:
    Abstract ( )   PDF (1179KB) ( )  
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    In order to overcome the elementary heterogeneous nucleation while octahydro trisodium salt
    of fructose-1,6-diphosphate(FDPNaa.8 H2O) is crystallized with ethanol precipitation at low
    temperature, a new crystallizationmethod with alcohol precipitation combined with salt
    precipitation has been presented. The ethanol-sodium ac-etate system for crystallization of
    salt of fructose-1,6-diphosphate is based on the mechanism of crystallization ofFDPNa3.8
    H2O in the ethanol-low temperature system. It is found that crystal size may be controlled
    by regulatingtemperature or pH value of solution in the crystallization process, and the
    crystal yield increases to 95% from 78%which obtained in the ethanol-low temperature
    system.
    Lumped Time Distribution Function of Dynamic Equilibrium System and Its Application in
    Calculating Molecular Weight Distribution of Polymer
    LI Hongbo, SUN Jianzhong, LIU Qing, WENG Zhixue, PAN Zuren
    2002, 10(2):  212-217.  doi:
    Abstract ( )   PDF (1546KB) ( )  
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    The lumped time distribution functions were proposed, which can be used for describing the
    dynamicsystems with two or more than two states of the end of growing polymer chain during
    chain addition polymerization.Numerical analysis of the lumped time distribution functions
    was carried out. The method for calculating molecularweight distribution of polymer in the
    stable free radical polymerization and more general cases was developed basedon the lumped
    time distribution functions.
    Copolymerization Kinetics of Ethylene Oxide and Propylene Oxide
    YIN Hong, CHEN Zhirong
    2002, 10(2):  218-222.  doi:
    Abstract ( )   PDF (1169KB) ( )  
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    The copolymerization kinetics of ethylene oxide and propylene oxide in an atomizing-
    circulation reactorunder semi-continuous operation is studied which is of great importance
    for molecular designation. The kineticparameters are obtained by numerical optimization of
    the kinetic model.
    Study on Critical Properties for CO2+Cosolvent Binary System and Ternary System
    ZHANG Jingchang, WU Xiangyang, CAOWeiliang
    2002, 10(2):  223-227.  doi:
    Abstract ( )   PDF (1295KB) ( )  
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    The performance of supercritical fluid (SCF) as a solvent can be greatly affected by
    addition of anentrainer to the system. In this study, a constant volume visual method is
    used to measure the critical point ofCO2+n-butyraldehyde, CO2+ i-butyraldehyde and
    CO2+alcohol binary systems and CO2+entrainer+trisodiumsalt of tri-(m-sulfonphenyl)phosphine
    (TPPTS) ternary systems, which provides us good theoretical basis for super-critical
    extraction and chemical reaction. The relationship between critical point and concentration
    of the entrainerare discussed. The phase behavior of binary system and that of ternary
    system are compared. The relationshipbetween the concentration of TPPTS and critical point
    of binary systems are also discussed.
    REVIEWS
    Progress in Pressure Swing Adsorption Models During the Recent 30 Years
    ZENG Rong, GUAN Jianyu
    2002, 10(2):  228-235.  doi:
    Abstract ( )   PDF (2984KB) ( )  
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    The pressure swing adsorption (PSA) models discussed here are divided into three
    categories: partialdifferential equation model, electrical analogue model and neural
    network model. The partial differential equationmodel, including equilibrium and kinetic
    models, has provided an elementary viewpoint for PSA processes. Usingthe simplest
    equilibrium models, some influential factors, such as pressurization with product,
    incomplete purge,beds with dead volume and heat effects, are discussed respectively. With
    several approximate assumptions i.e.,concentration profile in adsorbent, "frozen" column,
    symmetry and heat effects of bed wall, the more complexkinetic models can be simplified to
    a certain degree at the expense of a limited application. It has also been foundthat the
    electrical analogue model has great flexibility to handle more realistic PSA processes
    without any additionalhypothesis.
    RESEARCH NOTES
    Investigation of Bicengineering, the Metabolic Flux Analysis Method for Overdetermined
    System
    MA Hongwu, GUO Xiaofeng, ZHAO Xueming, LU Jin
    2002, 10(2):  236-239.  doi:
    Abstract ( )   PDF (1094KB) ( )  
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    With the xanthan synthesis in Xanthomonas campestris as an example, two methods for
    metabolicflux analysis of overdetermined system, the experimental data error minimization
    method and the equation errorminimization method, are compared from their mathematical
    basis, rationality of the results and the easiness ofcomputation. The results show that the
    experimental data error minimization method is appropriate in metabolicflux analysis of
    overdetermined system.
    Effects of Hydrophobicity of Ethylene Oxide-Propylene Oxide Copolymers on Phase Diagrams of
    Aqueous Two-Phase Systems and Partition Behaviors of Cephalexin and 7-
    Aminodeacetoxicephalos Doranic Acid
    ZHU Jianhang, WEI Dongzhi, CAO Xuejun
    2002, 10(2):  240-243.  doi:
    Abstract ( )   PDF (1551KB) ( )  
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    A series of ethylene oxide (EO)-propylene oxide (PO) random co-polymers (EOPO) were used to
    formaqueous two-phase systems (ATPS) with ammonium sulfate. Effects of EOPO’s properties on
    the phase separationbehaviors and on the partition of cephalexin and 7-
    aminodesacetoxicephalosporanic acid (7-ADCA) in ATPS wereinvestigated. Both the molar mass
    and molar ratio of EO to PO of EOPO could greatly influence partition behaviorsof
    cephalexin and 7-ADCA as well as the binodal curve of ATPS. With the increase of molar mass
    of co-polymeror the decrease of molar ratio of EO to PO, the critical point of ATPS
    decreased, the binodal curve became moreasymmetry, and both cephalexin and 7-ADCA followed
    the same tendency to partition into the polymer-poorbottom phase. The experimental results
    shows that it is feasible to partition cephalexin and 7-ADCA in either thepolymer-rich top
    phase or the polymer-poor bottom phase by choosing a specific phase-forming EOPO.
    Optical Resolution of DL-Tartaric Acid Mediated by Diastereomeric Salts Crystallization: A
    Useful Method for Exploring and Optimizing Experimental Conditions
    Lola Kokila, CAI Shuihong, CHEN Kongchang
    2002, 10(2):  244-248.  doi:
    Abstract ( )   PDF (1359KB) ( )  
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    A response surface modeling approach for simultaneous optimization of optical purity and
    yield wasapplied to the resolution of tartaric acid to study the effects of both the amount
    of the solvent and the amountof the resolving agent α-methylbenzyl amine on the resolution
    results. The direction of changing the experimen-tal conditions was determined from the
    initial response study, and expected high yield of the pure L(+)-tartaricacid-L(-)-α-
    methylbenzyl amine salt was obtained.
    Assessing Risk in Chemical Plant with Pattern Matching
    P. K. Bandyopadhyay, S. C. Roy, S. N. Sen
    2002, 10(2):  249-253.  doi:
    Abstract ( )   PDF (1677KB) ( )  
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    This paper discusses potential application of fuzzy set theory, more specifically, pattern
    matching, in assessing risk in chemical plants. Risk factors have been evaluated using
    linguistic representations of the quantity of the hazardous substance involved, its
    frequency of interaction with the environment, severity of its impact and the uncertainty
    involved in its detection in advance. For each linguistic value there is a corresponding
    membership function ranging over a universe of discourse. The risk scenario created by a
    hazard/hazardous situation having highest degree of featural value is taken as the known
    pattern. Each sample pattern of hazard/hazardous situation with their known featural values
    is then matched with the known pattern. The concept of multifeature pattern matching based
    on fuzzy logic is used to derive the rank ordering of process hazards. In multifeature
    pattern recognition/matching, a sample pattern is compared to a number of known data
    patterns or a known pattern is compared to a number of sample data patterns. The process
    assesses which known pattern resembles most closely data sample using Wang’s approaching
    degree method. A methodology has been developed and the same has been exemplified by
    presenting a case example with a limited number of hazards.
    An Experimental Study on Distribution of Vertical Stress in a Silo with a Central Inner
    Downcomer
    JING Shan, YI Jianglin, WANG Jinfu, WANG Zhanwen, JIN Yong
    2002, 10(2):  254-257.  doi:
    Abstract ( )   PDF (953KB) ( )  
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    The distribution of vertical stress for both active and passive state in the silo with a
    central innerdowncomer is reported in this paper. Experimental measurement of the axial
    distribution of vertical stress for bothactive and passive state in the silo are in good
    agreement with that predicted by theoretical analysis. The meanaxial stress is reduced due
    to the presence of the inner downcomer in the silo.