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Table of Content
25 March 2001, Volume 52 Issue 3
    综述与专论
    STUDY AND PROGRESS ON INDUSTRIAL ECOLOGY AND ECO-INDUSTRIAL PARKS
    LI Yourun;SHEN Jingzhu;HU Shanying;CHEN Dingjiang
    2001, 52(3):  189-192. 
    Abstract ( 720 )   PDF (709KB) ( 524 )  
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    Industrial ecology (IE) and eco-industrial Park (EIP) have been the emerging frontiers for sustainable development in recent years. The latest academic and practical progresses of IE and EIP are introduced in this paper. The study of IE with the approach of process systems engineering is especially pointed out, including mass integration and energy integration in an industrial ecosystem. Mass integration aims to utilize materials and minimize wastes to the maximal extents. It includes synthesis of reaction path and synthesis of mass exchange network for purification. The authors’ work on reaction path synthesis is introduced. The energy integration aims to utilize energy effectively. Mass and energy integration in the context of industrial ecosystem will greatly improve the economic and environmental efficiency of EIP. Some other areas needed further study are also outlined in this paper. The areas include the study of the analogy between industrial ecosystem and non-human biological ecosystem with the concept of energy and exergy, the study of information system and decision support system for EIP, the study of the flexibility of EIP under uncertain factors, etc.
    研究快报
    ADSORPTION OF METHANE ON SINGLE WALL CARBON NANOTUBES BY DENSITY FUNCTIONAL THEORY
    ZHANG Xianren;WANG Wenchuan
    2001, 52(3):  193-194. 
    Abstract ( 702 )   PDF (254KB) ( 179 )  
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    The density functional theory(DFT)is used for the description of adsorption of methane on single walled carbon nanotubes(SWNT). Methane molecule is modeled by the Lennard-Jones potential,while the interaction between wall- fluid molecules is represented by the potential function proposed by Tjatjopoulos et al. To verify the DFT method, a comparison of the local density profiles and adsorption isotherms from the DFT and computer simulation for the tube diameter of 4.077 nm at 300 K is presented. Furthermore, adsorption isotherms for the SWNT of diameter 1.632 , 2.04 ,3.805 and 4.077 nm at 148 K are given in this short communication as a preliminary report.
    DESIGN AND APPLICATION OF FLUIDIZED BED PHOTOCATALYTIC REACTOR
    CUI Peng;FAN Yiqun;XU Nanping;SHI Jun
    2001, 52(3):  195-196. 
    Abstract ( 536 )   PDF (190KB) ( 106 )  
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    研究论文
    EXPERIMENTAL STUDY ON BUBBLE SIZE DISTRIBUTION IN THREE-PHASE CIRCULATING FLUIDIZED BEDS
    WANG Tiefeng;WANG Jinfu;YANG Weiguo;JIN Yong
    2001, 52(3):  197-203. 
    Abstract ( 624 )   PDF (912KB) ( 209 )  
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    The bubble size and its distribution has been studied in three-phase circulating fluidized beds by using the newly developed fiber optic probe system systematically. The experimental results show that the distribution of the bubble size can be described by the lognormal distribution function. The mean bubble size in the center region of the fluidized bed is smaller than that in the region near the reactor wall. The mean bubble size decreases with the superficial gas velocity and increases with the particle-circulating rate. The superficial liquid velocity has almost no effect on the mean bubble size.
    MODEL FOR PREDICTION OF CIRCUMFERENTIAL DISTRIBUTION OF FILM THICKNESS IN HORIZONTAL GAS-LIQUID ANNULAR FLOW
    LI Weidong;LI Rongxian;WANG Yueshe;ZHOU Fangde
    2001, 52(3):  204-208. 
    Abstract ( 657 )   PDF (603KB) ( 160 )  
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    For annular flow in a horizontal pipe, the gravity force resulted in an asymmetric distribution of the liquid film flowing along the pipe wall. Using five parallel-wire conductance probes, time records were collected on local liquid film thickness at five circumferential positions. The liquid upward transport mechanism is very important for predicting the circumferential liquid film thickness distribution in horizontal gas-liquid annular flow. Taking into consideration the pumping action of disturbance waves, the induced secondary flow in the gas flow, entrainment and deposition of droplets a theoretical model of circumferential distribution of liquid film thickness was developed with stress balance and order analysis method. The filmthickness distribution obtained from the model accorded with the experimental data very well.

    FLOW CHARACTERISTIC OF GAS-LIQUID TWO-PHASE ANNULAR FLOW THROUGH ANNULAR NARROW PASSAGE
    HUANG Xinghua;WANG Qijie;LU Zhen;XU Bin
    2001, 52(3):  209-215. 
    Abstract ( 785 )   PDF (834KB) ( 162 )  
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    A mathematical model for predicting the pressure drop characteristic of gas-liquid two-phase annular-mist flow through an annular narrow passage is presented. The flow model takes into account the compressibility of the gas core fluid, the phase slip and droplets entrainment in the gas core flow. The assumed vena contracta effect of the mist core flow through annular narrow passage is considered by applying discharge coefficient for pure air flow. A force balance method is applied to spherical droplets to calculate the phase slip ratio of the mist core flow at the throat cross-section of the annular narrow passage. The effects of two-phase mass flow rate and mass flow quality on pressure drop, cross-section area of the core flow at throat, relative variety of droplet velocity are disscussed in detail. To verify the proposed model the computed two-phase pressure drop is compared with experimental data of air-water mixture for different annular narrow passages and different inlet conditions,and a good agreement between the simulation results and experimental ones is obtained.
    EXTRACTION OF L-TRYPTOPHANE WITH DI(2-ETHYLHEXYL)PHOSPHORIC ACID
    LIU Yangsheng;DAI Youyuan
    2001, 52(3):  216-221. 
    Abstract ( 704 )   PDF (729KB) ( 238 )  
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    A series of equilibrium experiments for extracting L-tryptophane with di(2-ethylhexyl)phosphoric acid (D2EHPA) dissolved in n -octane (system A) and mixture of n -octane and n -octanol (system B) were carried out.The effects of L-tryptophane concentration, D2EHPA concentration, n -octanol concentration and pH on extraction distribution ratio were discussed in detail. In system A, in the range of 1.0
    化工学报
    LIQUID CIRCULATION RATE AND VOLUMETRIC MASS TRANSFER COEFFICIENT IN MULTI-TUBE AIRLIFT LOOP REACTOR
    LIU Yongmin LIU Zheng and YUAN Naiju (Department of Petrochemical Engineering, (Department of Chemical Engineering, Fushun Petroleum Institute,Fushun 113001,Liaoning,China) Tsinghua University, Beijing 10
    2001, 52(3):  222-226. 
    Abstract ( 613 )   PDF (696KB) ( 226 )  
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    A correlation of liquid circulation rate in a multi-tube air-lift loop reactor(MALR) was established on the basis of the momentum balance, in which a new method for the determination of the overall frictional-loss coefficient in air-water system was developed. The method for determining the exposure time of liquid particle in the gas-liquid interphase was proposed, which formed the basis for the calculation of volumetric mass transfer coefficient of gas component according to Higbies penetration theory. The validity of these two correlations was demonstrated by the fairly good agreements between the calculated liquid rate and mass transfer coefficients with the experimental data.
    ADSORPTION BEHAVIOR OF PARTICLE IN POLYELECTROLYTE SOLUTION AND INTERACTION BETWEEN TWO PARTICLES ADSORBING POLYMER (I MATHEMATICAL MODEL
    JI Junhui (National Engineering Research Center of Engineering Plastics, Institute of Chemistry, Chinese Academy of Science, Beijing 100080,China)
    2001, 52(3):  227-231. 
    Abstract ( 616 )   PDF (568KB) ( 94 )  
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    Mathematical models for particle adsorbing polymer chains from polyelelctrolyte solution and the interaction between two particles adsorbing polymer were derived by adopting predecessor-determined random walk model (PDRWM) on the basis of self-consistent field and statistical thermodynamics. The interactions among particle, polymer segment and solvent molecule, as well as the effect of charged groups in polymer chains were taken into account in these models. The profile of segment density distribution was derived. The change of free energy of the interaction between two particles adsorbing polymer was also derived according to the change in particle surface free energy.
    ADSORPTION BEHAVIOR OF PARTICLE IN POLYELECTROLYTE SOLUTION AND INTERACTION BETWEEN TWO PARTICLES ADSORBING POLYMER (II) NUMERICAL ANALYSIS,RESULTS AND DISCUSSIONS
    JI Junhui (National Engineering Research Center of Engineering Plastics, Institute of Chemistry, Chinese Academy of Science, Beijing 100080,China)
    2001, 52(3):  232-235. 
    Abstract ( 606 )   PDF (500KB) ( 104 )  
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    The profile of segment density distribution was numerically analyzed by means of the Newdon-Raphson iteration method. The conformation of polymer chains adsorbed on the surface of particle was theoretically studied, the effects of molecular weight of polymer, the density of charged group in polymer chains and the interaction coefficients between polymer segment and solvent molecule and between polymer and particle surface were also theoretically investigated. The carbon black dispersion system with polyacrylamide (PAM) or cationic polyacrylamide (CPAM) as dispersant was adopted to verify the model.
    NETWORK ANALYSIS OF TERNARY GAS DIFFUSION IN POROUS MEDIA
    XIN Feng,HAN Sen,YIN Xiaohong,LIAO Hui and LI Shaofen (School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072,China)
    2001, 52(3):  236-240. 
    Abstract ( 694 )   PDF (602KB) ( 169 )  
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    Diffusion of ternary gas mixture of ethylene, argon and carbon dioxide in γ -Al 2O 3 was analyzed based on the network approach with the effective medium theory and smooth field approximation, and was verified by the Wicke-Kallenbach steady state diffusion experiment. The diffusion flux equation,including pore size distribution and pore structure parameter—mean coordination number,was calculated to get the diffusion properties of each substance without prior knowledge of the tortuosity of porous media from diffusion experiment. The alumina used in diffusion experiment had a larger range of pore radii from 1.0 to 1000.0 nm, which was cut into three intervals according to the three peaks on the diagram of mercury injection curve.The pore size and pore structure parameter could be obtained by sorption experiment. The diffusion experiment was carried out in an atmospheric cell,with temperature from 320~430 K. The results showed that the multi-component diffusion could be resolved with network analysis when pore structure (mean coordination number) and pore size (pore size distribution) parameters were known. After all, a useful method was established to describe the macro-properties of diffusion from the microstructure of porous media.
    PREDICTION OF FLOW FIELDS GENERATED BY RUSHTON TURBINE
    HOU Shuandi ZHANG Zheng,WANG Yingchen and SHI Litian (Research Institute of Petroleum Processing,Beijing 100083,China) (Beijing University of Chemical Technology, Beijing 100029,China)
    2001, 52(3):  241-246. 
    Abstract ( 600 )   PDF (667KB) ( 234 )  
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    Two sets of instantaneous flow fields generated by a Rushton turbine are simulated in the rotating reference coordinate based on standard k-ε turbulent model.The model predictions successfully reproduce the “two circulation loop” flow pattern in a Rushton turbine stirred tank. The simulation-results also show that the radial flow pattern is transferred to axial flow pattern at C/T ?=?0.167. The model prediction power number ( N p) and the impeller flow number ( N qd ) are in good agreement with the experimental data. The model prediction velocity distributions of this study agree with experimental measurements,and are in closer agreement with the experimental data than those based on “block box” method.
    TEMPERATURE MATCHING FOR CFB REACTOR SYSTEMS FOR SELECTIVE OXIDATION OF n -BUTANE TO MALEIC ANHYDRIDE(I) FREACTOR SYSTEM MODELS
    LIU Hui,HUANG Xiaofeng,LI Chengyue and CHEN Biaohua (The Key Laboratory of Science and Technology of Controllable Chemical Reactions,Ministry of Education,Beijing University of Chemical Technology,Beijing?100029,China)
    2001, 52(3):  247-251. 
    Abstract ( 630 )   PDF (629KB) ( 174 )  
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    An one dimensional heterogeneous model for describing selective oxidation of butane to maleic anhydride over a domestic commercial VPO catalyst in the riser of a CFB(circulating fluidized bed)system and a bubbling bed model for the regeneration of the catalyst in the fluidized bed of this CFB reactor system are developed,respectively,to preliminarily explore controlling strategy of the spatial separation catalytic cycle which combines selective oxidation of n -butane and regeneration of the catalyst.Simulation results show that based on the regeneration kinetics of the catalyst,properly raising the reoxidation temperature of the catalyst in the fluidized bed reactor either can obviously improve the performance of the system or can reduce the solid flux and hence the energy consumption.Part I of this paper presents the models of the CFB system and computation method.
    EXPERIMENTAL STUDY OF N_2O EMISSION IN COAL-FIRED PFBC
    SHEN Laihong SUZUKI Yoshizo (Institute of Thermo-energy Engineering,Southeast (National Institute for Resources and University,Nanjing 210096,Jiangsu,China) Environment,Tsukuba 305,Japan)
    2001, 52(3):  252-255. 
    Abstract ( 582 )   PDF (640KB) ( 119 )  
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    In this paper the emphasis is laid on the experimental investigation, description of the influences of bed temperature, O 2 level and operating pressure on emission of N 2O in a coal-fired pressurized fluidized bed combustor(PFBC).An increase of bed temperature gives a decrease of N 2O formation, but slightly affects NO formation.The result of NO emission is different from that in atmospheric fluidized bed combustor(AFBC). An increase of O 2 level can give an increase of N 2O and NO emissions, but the effect of O 2 level on N 2O emission is weaker. With the increase of operating pressure, NO emission decreases remarkably, while N 2O emission increases.
    EXPERIMENTAL INVESTIGATION OF HEAT TRANSFER ENHANCEMENT BY FLOW INDUCED VIBRATION IN STEAM-WATER HEAT EXCHANGERS
    TIAN Maocheng, LIN Yiqing, CHENG Lin and ZHANG Guanmin (Department of Power,Shandong University, Jinan?250061,Shandong,China)ZHOU Qiangtai (Department of Power,Southeast University, Nanjing?210096,Jiangsu,China)
    2001, 52(3):  257-261. 
    Abstract ( 637 )   PDF (631KB) ( 409 )  
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    A new concept of the compound heat transfer augmentation by flow-induced vibration was put forward in steam-water heat exchangers. The vibration of heat transfer surface can increase the heat transfer coefficient.In the meantime, the vibration of the tubes can also remove the fouling adhered to the tube surface easily, and therefore, the fouling thermal resistance can be decreased. Experiments were carried out on the vibration and heat transfer characteristics of the elastic tube bundles used in steam-water heat exchanger. Experimental results showed that the tube bundles vibrated mainly at its lower natural frequencies in crossflow, whereas, for the in-tube flow, they vibrated randomly at a wide range of frequencies. Experiments of heat transfer characteristics revealed that the convective heat transfer coefficient of the outside tube was greatly raised while that of the inside tube rose slightly. Generally, the outside average convective heat transfer coefficient for the elastic tube bundles is five times that of the fixed tube bundles at the same Re .The mechanism of reduction of fouling thermal resistance has been analyzed.
    SYNERGISTIC INHIBITION OF Tw-20 AND POLYACRYLIC ACID ON IRON CORROSION IN HYDROCHLORIC ACID
    GUO Ying SONG Shizhe (Department of Basic Sciences, Civil Aviation (College of Materials,Tianjin University, Institute of China, Tianjin ?300300,China) Tianjin?300072,China)
    2001, 52(3):  262-265. 
    Abstract ( 848 )   PDF (576KB) ( 231 )  
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    The synergistic inhibition by nonionic surfactant Tw-20 and polyacrylic acid (PAAC) for pure iron in HCl solution is studied by using stable state polarization curves,polarization Resistace ( R p) and EIS.The results show that Tw-20 has marked synergism with PAAC on the inhibition of corrosion of iron in HCl solution. It is found that a small amount of Tw-20 could improve the protection efficiency of low-concentration PAAC in Fe/HCl system from 68?% to above 92?%.The synergistic inhibition mechanism of Tw-20 and polyacrylic acid is studied. It is show that Tw-20 is adsorpted on the iron-solution interface, improving the surface moisten degree of the iron and dispersibility of polyacrylic acid in the solution. The adsorption of polacrylic acid on the iron surface is thus improved and in this way, the inhibition characteristic of polacrylic acid is greatly improved.
    FLOTATION OF Cu(Ⅱ) BY COLLOIDAL GAS APHRONS(CGA)
    WANG Yundong,WEN Hanzhen and DAI Youyuan (Department of Chemical Engineering,Tsinghua University,Beijing?100084,China)
    2001, 52(3):  266-268. 
    Abstract ( 682 )   PDF (455KB) ( 105 )  
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    Colloidal gas aphrons(CGAs) were first defined by Sebba( J.Colloid Interface Sci .,1971,35(4):643) as micro bubbles(25—300?μm).These microbubbles do not coalesce easily and are markedly different from conventional soap bubbles in their stability and flow properties.CGAs are composed of a gaseous inner core surrounded by a thin surfactant film, which are created by intense stirring of a surfactant solution. CGA dispersion typically contains about 65% gas. CGA suspensions have viscosity similar to water, which make them suitable for pumping without deterioration in quality. Two important considerations in the application of CGA suspensions are: ① their colloidal size, resulting in a large surface area to volume ratio, and ② the existence of a double film of surfactant encapsulating the gas that retards the coalescence of the bubble. CGA suspensions are found very effective for separating hydrophobic organic compounds and heavy metal ions. In this paper, flotation of Cu(Ⅱ) by colloidal gas aphrons has been conducted in order to explore a new method for separating heavy metal ions from dilute solution. The effects of CGA flow rate, amounts of CGA introduced to the system, surfactant concentration on the flotation efficiency have been systematically investigated. The optimum flotation condition is determined. The results show that flotation efficiency at pH=5—6 has an optimum value to CGA flow rate and amount. When pH is greater than 7, the flotation efficiency can be as high as 99% at the optimum condition.
    APPLICATION OF MEASURING COKING IN CRACKING FURNACE TUBE WITH γ -RAY TRANSMISSION TECHNIQUE
    FENG Ruijiang and SHI Weizhen (Department of Petrochemical Engineering,Fushun Petroleum Institute,Fushun 113001,Liaoning,China)
    2001, 52(3):  270-272. 
    Abstract ( 840 )   PDF (376KB) ( 124 )  
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    In this paper,the basic principle of γ -ray transmission technique is introduced. Through the study of single tube coking experiments,the possibility of the application of γ -ray transmission technique in furnace tubes is also discussed. The effects of cracking temperature,retention period and steam dilution ratio on coking rate are investigated .Comparing to the results by means of coupon weighing weight, γ -ray transmission technique is feasible for coking measurement. The results are consistent with other reported data in literature.
    TEMPERATURE FIELD MODEL OF TWO-STAGE UNDERGROUND COAL GASIFICATION
    YANG Lanhe (College of Mineral Resource and Environmental Science, China University of Mining and Technology,Xuzhou?221008,Jiangsu,China)
    2001, 52(3):  273-276. 
    Abstract ( 717 )   PDF (503KB) ( 144 )  
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    Two-stage underground coal gasification is an effective method which can produce water gas with high heating value,while the temperature is the key factor that determines on its producing process. On the basis of model test, the mathematical model for two dimensions, non-linear, unsteady temperature field is established through analyzing the distribution law of temperature field for combustion and gasification of coal seam in the stove, and outlining and treating the boundary conditions. A selection method of the model parameters has been introduced. The mathematical model is solved by the control volume method,and calculation results are analysed. The uniformity of calculation and real measurement value indicate that the numerical simulation of dynamic state temperature field for the coal seam medium in the gasification stove is correct.Thereby,it provides a necessarily theoretical base for further quantitative study on process of underground coal gasification.
    TREATMENT OF PHENOL-CONTAINING WASTEWATER USING UV/H_2O_2 SYSTEMS
    WU Zucheng and LI Wei (Institute for Environmental Science and Engineering, Zhejiang University,Hangzhou 310027,Zhejiang,China)
    2001, 52(3):  277-280. 
    Abstract ( 643 )   PDF (496KB) ( 281 )  
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    In this paper, the treatment of phenol-containing wastewater is studied by using UV/H 2O 2 system in a bench scale. The influence factors including concentration of H 2O 2 and phenol, pH, and some metal ions are investigated. The addition of H 2O 2 was favorable to the removal of phenol, however, the excess of H 2O 2 does not significantly affect the removal efficiency. It has shown that changes in reaction rates are rather insignificant over a wide pH range from 3 to 8. The co-existence of metal ions has significant influence upon the photocatalytic reaction rates, Fe 2+ increases the reaction rates, but Co 2O 3 and Zn 2+ given negative results. The mechanism of the reaction process is also discussed with chromatograms of phenol and its intermediate products.