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Table of Content
25 August 1996, Volume 47 Issue 4
    化工学报
    EFFECTS OF BOUNDARY LAYER MASS TRANSFER RESISTANCE ON THE SEPARATION PERFORMANCE OF MEMBRANE PERMEATORS
    Chen Hua;Can Chun;Jiang Guoliang(Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023)
    1996, 47(4):  387-393. 
    Abstract ( 574 )   PDF (387KB) ( 159 )  
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    In this work,a series-resistance model is developed and verified experimentally to account for the mass-transfer resistances througth boundary layers as well as the permeation resistance through the membrane.According to this mode1,the effictive separation factor is always lower than the ideal separation factor of the membrane.To increase the effective separation factor of the permeators,mass transfer coefficient at the feed side should be enhanced.
    SOLUBILITY MODEL OF SOME ORGANIC SUBSTANCES IN SUPERCRITICAL FLUIDS
    Jiang Chunyue;Pan Qinmin;Pan Zuren(Institute of Polymer Science and Engineerng,Zhejiang University,Hangzhou 310027)
    1996, 47(4):  394-400. 
    Abstract ( 466 )   PDF (333KB) ( 127 )  
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    The study on solubilities of substances in dense gases is one of the most important tasks in supercritical fluid extraction(SFE).On the basis of the association laws and the adsorption theories,this paper puts forward a kind of physicochemical mechanism of SFE.Based on this mechanism an adsorption/association model for calculating solubilities of substances in a supercritical fluid(SCF)has been derived.Some experimental results from the literature were reproduced by means of this model.Very good agreement with these experimental results is found.The physicochemical mechanism reasonably accords with the real process of SFE.
    MOLECULAR THERMODYNAMICS OF SALT EFFECT IN VAPOR-LIQUID EQUILIBRIUM——CALCULATION OF ISOBARIC VLE SALT EFFECT PARAMETERS FOR ETHANOL-WATER-1-1 TYPE ELECTROLYTIC SYSTEMS
    Sun Renyi(Department of Chemistry,Henan University,Kaifeng 475001)
    1996, 47(4):  401-409. 
    Abstract ( 652 )   PDF (447KB) ( 174 )  
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    Salt effect parameters(from Furlers equation)of 6 ethanol-water-1-1 type electrolytic (LiC 、LiBr、NaBr、NaAc、KCI、KI)systems were determined by isobaric VLE experi ments.A calculation method of these parameters at any nonelectrolytic concentration was pro- posed based on Pierottis scaled particle theory.The term of hard sphere interaction was calculated by Masterton-Lees equation.The term of soft sphere interaction was calculated by Hu Yings molecular thermodynamic model,in which the diameter of naked ion was replaced by solvated ion and solvation coefficient was taken to be a adjustable parameter.A correlation equation for the locallzed dielectrical constant of mixture and liquid concentration was obtained by mapping out experimental point.The calculated isobaric VLE salt effect parameters of 14 ethanol-water-1-1 type electrolytic systems were in good agreement with literature values and experimental values of this work within the wider range of Liquid concentration.
    STUDY ON DISTILLATION FLOWSHEETS WITH COMPLEX COLUMNS FOR SEPARATION OF FIVE-COMPONENT MIXTURES
    Rong Benguang;Li Mei;Hu Yangdong;Han Fangyu;Guo Tianmin(Research Center for Computers and Chemical Engineering,Qingdao Institute of Chemical Technology,Qingdao 266042)(Petroleum University,Beijing 100083)
    1996, 47(4):  410-419. 
    Abstract ( 558 )   PDF (585KB) ( 204 )  
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    Twenty two distillation flowsheets are studied for the separation of five-component mixtures based on energy consumption and annual costs.Fourteen flowsheets with simple columns and eight flowsheets with complex columns of side strippers and/or side rectifiers are included. Several five-component mixtures are selected,and for various cases of feed composition distribution,the costs of the flowsheets are calculated and compared.Several heuristics are produced for the synthesis of distillation flowsheets with complex columns.
    GENETIC ALGORITHMS AND ARTIFICIAL NEURAL NETWORK(Ⅱ)──TRAINING ARTIFICIAL NEURAL NETWORK BY EGA-GDR
    Chen Fangze;Chen Bingzhen;He Xiaorong(Department of Chemical Engineering,Tsinghua University,Beijing 100084)
    1996, 47(4):  421-426. 
    Abstract ( 548 )   PDF (296KB) ( 228 )  
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    In order to overcome a local optimal solution which often occurs in the training process of ANN,a new algorithm,called EGA-GDR,is proposed,which combines the perfect characters of both EGA and GDR.The results obtained from training two ANNs whose structures are2×3×1 and8×8×4 respectively,show that EGA-GDR can more effectively search the optimal solution than SA—GDR does.
    THEORETICAL PREDICTION AND EXPERIMENTAL INVESTIGATION OF FINNED TUBES THERMAL CONTACT RESISTANCE
    Yang Xiaoqiong;Wang Qijie;Wang Xiaojun(Department of Power Machinery engineering,Xian Jiaotong University,Xian 710049)
    1996, 47(4):  427-432. 
    Abstract ( 648 )   PDF (302KB) ( 117 )  
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    Based on previous investigation an improved model is presented for predicting thermalcontact resistance of finned tubes.Fin efficiency is used directly in the model and iteration algorithm is recommended so that the accuracy of prediction is improved considerably.For examination of the model,expreimental study is carried out,it is shown that experimental data and predicted values are in good agreement.
    APPLICATION OF NEURAL NETWORK MODEL IN VITAMIN C FERMEMTATION PROCESS
    Hua Qiang;Wang Shuqing(Institute of Industrial Process Control,Zhejiang Universty,Hangzhou 310027)
    1996, 47(4):  433-438. 
    Abstract ( 588 )   PDF (337KB) ( 129 )  
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    Conventional standard artificial neural network has been applied widely in state estimation of bioprocesses,but hybrid neural network,which combines the prior knowledge or partially known principles of the process,can give more satisfactory results.The hybrid model is used in state estimation of 2-keto-l-gulonic acid fermentation in this paper,and the results are compared with that of standard neural network.
    MODELLING THE SIMULATED MOVING BED PAREX PROCESS
    Gu Jinsheng;Jiang Weisun(Research Institute of Automation,East China University of Science and Technology,Shanghai 200237)
    1996, 47(4):  439-446. 
    Abstract ( 679 )   PDF (414KB) ( 119 )  
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    A steady state model using linear driving force is proposed in this paper for describing the simulated moving bed Parex process,and concentration profiles of PX,MX,OX,EB and PDEB are obtained by solving this mathematical model.Calculated results conform well with actual measurement data on the basis of this model,the effects of the change in operational parame ter have been simulated.
    PROCESSING OF ASCHARITE-MAGNETITE SYNGENETIC MINERAL BY SULFURIC ACID(Ⅰ)──DIGESTION RETARDATION OF MAGNETITE AND ITS MECHANISM
    Ye Yaping;Lu Bingling(School of Chemical Engineering,Dalian University of Technology,Dalian 116012)
    1996, 47(4):  447-453. 
    Abstract ( 822 )   PDF (368KB) ( 118 )  
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    In the digestion of ascharite-magnetite syngenetic mineral,sodium chlorate acts as the digestion retardant of magnetite and as digestion promotor of uraninite.Sodium chlorate oxidizes Fe3O4 to Fe2O3,the smaller reaction ability of Fc2O3 depress the digestion rate of magnetite.Furthermore,the formation of apassivation film on the surface of magnetite reduces the effect of“Corrosion cell of Fe3O4-FexS”,which also decelerate the digestion rate of magnetite,This mechanism has been confirmed by Mossbauer spectroscopy and anodic polarization measurement.
    PROCESSING 0F ASCHARITE-MAGNETITE SYNGENETIC MINERAL BY SULFURIC ACID(Ⅱ)──PHASE DIAGRAMS OF H_3BO_3-MgSO_4-MgCl_2-H_2O SYSTEM AT 25℃ AND 100℃ AND THEIR APPLICATION
    Cao Jilin;Zhao Bet;Liu Shuqin;Zhang Mingjiu;Lu Bingling(School of Chemical Engineering,Dalian University of Technology,Dalian 116012)
    1996, 47(4):  454-460. 
    Abstract ( 829 )   PDF (372KB) ( 169 )  
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    The solubilites of H3BO3-MgSO4-MgC12-H2O systems at 25°and 100℃ determined and the phase diagrams are plotted.On the basis of these diagrams,in evaporation of the aqueous solution of H3BO3-MgSO4,with MgC12 as salting out agent,MgSO4·H2O can be precipitated.On cooling down the MgSO4 mother liquor,boric acid can be crystallized out.The H3BO3 mother liquor can be recycled and used as salting out sgent againn,thus H3BO3 and MgSO4 can be throughly separated.In this paper,the optimum concentration of MgCl2 is also discussed.
    SYNTHESIS OF CYANOANILINE DERIVATIVES AND INVESTIGATION OF SHG ACTIVITY
    Chen Xing;Zhao Xiaoming;Cheng Lubai(Department of Fine Chemicals,Da1ian University of Technology,Dalian 116012)
    1996, 47(4):  461-465. 
    Abstract ( 735 )   PDF (199KB) ( 163 )  
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    Eighteen cyanoaniline derivatives were synthesized and there were 13 compounds having a chiral atom in them.The optical rotation and absorption curves were measured and it was found that the compounds having a chiral atom showed optical activity and the maximum absorption wavelengths of 18 synthesized compounds were between 400 and 415nm.Second harmonic generation(SHG)of synthesized compounds were measured by the powder method and it was found that 8 samples were revealed to possess SHU activity.The influence of the molecular structure on SHG was examined by X-ray crystal analysis.
    SWELLING EQUILIBRIUM MODEL OF PERVAPORATION DENSE MEMBRANE IN BINARY ALCOHOL/WATER MIXTURES
    Chen Fengrong;Chen Hongfang(Department of Chemical Engineering,Tianjin University,Tianjin 300072)
    1996, 47(4):  466-473. 
    Abstract ( 560 )   PDF (374KB) ( 91 )  
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    The swelling equilibrium for the system water-ethylene glycol-crosslinked PVA at various temperatures were experimentally investigated.A liquid-membrane swelling equilibrium model was developed on the basis of modified UNIQUAC equation and Flory-Huggins thermodynamics and good agreement between the derived equation predictions and the experimental values for the preferential sorption of water-ethylene glycol mixture in the crosslinked PVA membrane was obtained.
    DRYING OF SUSPENDING LIQUOR IN FLUIDIZED BED WITH INERT PARTICLES
    Chen Guohuan;Li Yonghui;Zhao Zhongxiang;Xing Yukun;Chen Jiang(Department of Chemical Engineering,Tianjin Uninversity,Tianjin 300072)(Tianjin Soda Plant,Tianjin 300450)
    1996, 47(4):  474-480. 
    Abstract ( 636 )   PDF (346KB) ( 207 )  
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    An experimental investigation on drying for five kinds of materials such as concrete admixture in a fluidized bed dryer with inert particles was carried out and a correlation to calculate volumetric heat transfer coefficient was established.The experimental result showed that the presence of inert particles could enhance heat transfer and mass transfer to incease the volumetric heat transfer coefficient to 3000 W·m~(-3)·K(-1),but the bed pressure drop was comparatively high.The drying capacity(as water evaporated)and heat efficency could reach 50—60kg·m-30·h-1and 30%—43% respectively,and furthermore would continue to increase with the entrance temperature of hot air.
    REACTION MECHANISM IN DESULFURIZTION OF FLUE GAS BY LOW TEMPERATURE PLASMA
    Li Ruinian;Yan Keping;Pu Yikang;Miao Jinsong;Wu Xiaoli(Department of Applied Physics,Beijing lnstitute of Technology,Beijing 100081)
    1996, 47(4):  481-487. 
    Abstract ( 566 )   PDF (373KB) ( 211 )  
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    As for the main reaction mechanism in desulfurization of flue gas by pulsed corna or electron beam,which generates low temperature plasmas,there were two presumptions:gas phase reactions and heterogeneous reactions.The results of this work indicate that with an appropriate partial pressure of water vapor,there exists liquid layers on the inner surfaces of the reactor and the solid deposits.The radicals of SO3 play an important role in the chain processes of oxidizing sulfite ons to sulfate ions.By solving the kinetic equations,it can be found that the hydroxyls absorbed by the liquid phase contribute over 80% percent of desulfurization rate,which is over ten times of that due to gas phase reactions.It suggests that the main mechanism is the plasma-activated liquid phase reactions.The calculated results not only agrde with the experiment but also predict the effect of effective area factor.The prediction is proved by the experiments.
    OZONATION OF 4-NITROPHENOL IN AQUEOUS SOLUTION
    Zhang Hui;Cheng Jiang;Yang Zhuoru;Chen Huanqin(Research Institute of Chemical Engineering,South China University of Technology,Guangzhou 510641)
    1996, 47(4):  488-494. 
    Abstract ( 534 )   PDF (326KB) ( 299 )  
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    The influence of operation conditions on the degradation of 4-nitrophenol in water by ozone was studied.The reaction between ozone and 4-nitrophenol can be regarded as slow and fast.pseudo first-order at pH2.0 and pH 5.8—12 respectively.The liquid-phase volumetric mass transfer coefficient of ozone in a bubble reactor and the rate constants were determined.The regression equations of kLa and k2 are expressed as follows
    CONTINUOUS COUNTER-CURRENT AQUEOUS TWO-PHASE EXTRACTION OF PROTEIN——MASS TRANSFER COEFFICIENT IN PACKED COLUMN
    Yan Gongxi;Zhu Ziqiang;Mei Lehe;Guan Yixin(Department of Chemical Engineering,Zhejiang University,Hangzhou 310027)
    1996, 47(4):  495-499. 
    Abstract ( 588 )   PDF (250KB) ( 99 )  
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    Fractional dispersed phase hold-up and dispersed side overall mass transfer coefficient for bvine serum albumin were measured in a 0.057m i.d.packed extraction column using a phosphate-polyethylene glycol 4000 system.Raschig rings and structured packing were used as packings.The effect of phase composition on mass transfer process was also studied.
    LUMPED PARAMETER NONLINEAR ANALYSIS OF STEAM-LIQUID TWO PHASE FLOW PRESSURE DROP OSCILLATION IN EVAPORATOR TUBES
    Zhou Yunlong;Shen Zhengming;Chen Tingkuan;Chen Xueiun(Department of Power,Northeast China Institute of Electric Power Engineering,Jilin 132012)(Xi’an Jiaotong University,Xian 132012)
    1996, 47(4):  500-504. 
    Abstract ( 567 )   PDF (214KB) ( 133 )  
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    The pressure drop oscillation is analyzed by using a lumped parameter nonlinear model in this paper.The results show that the pressure drop type instability can be described by a second order differential equation.The effect of operation conditions on the pressure drop oscillation can be expressed by two dimensionless parameters E,η Model results agree qualitatively with experimental results.
    AVAILABLE INTERPHASE AREA WITHIN CATALYTIC DISTILLATION COLUMN
    Xu Xien;Zheng Yuxiang;Wang Baoguo(Deptartment of Chemical Engineering,Tianjin University,Tianjin 300072)
    1996, 47(4):  505-509. 
    Abstract ( 602 )   PDF (220KB) ( 106 )  
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    Available interphase area is an important part of investigating catalytic distillation process by the use of a nonequilibrium stage rate model.In this paper the available interphase area,when gas and liquid flow countercurrently in catalyst bed within a distillation column,was measured by using the chemical method in which CO2 in the air is analyzed by Na2CO3-NaHCO3 buffer solution with AsO2 as catalyst.The surface renewal theory by Danckwerts was employed for data processing.
    CONSTRUCTION OF SPINNING DROP TENSIOMETER AND DETERMINATION OF LIQUID-LIQUID INTERFACIAL TENSION
    Wu Youting;Mei Lehe;Zhu Ziqiang;Yu Zhonghua(Department of Chemical Engineering,Zhejiang University,Hangzhou 310027)(Department of Mechanical Engineering,Zhejiang University,Hangzhou,310027)
    1996, 47(4):  510-514. 
    Abstract ( 760 )   PDF (266KB) ( 140 )  
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    In order to determine the low interfacial tension,a spinning drop interfacial tensiometer was constructed.The apparatus was calibrated by measuring the interfacial tension of some low molecular weight systems and polyethylene glycol /dextran aqueous two-phase systems,with the determination error of 3.The interfacial tensions of PEG1000/Na2SO4,PEG/MgSO4 and PEG1000/(NH4)2SO4 aqueous two-phase systems Were determined.It is found that the salt type has strong effect on the interfacial tension.