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Table of Content
25 June 1983, Volume 34 Issue 2
    化工学报
    Paired-Process Model for Pseudo Solid-Solid Reaction
    Shao Manjun Institute of Chemical Metallurey Academia Sinica
    1983, 34(2):  99-115. 
    Abstract ( 514 )   PDF (724KB) ( 244 )  
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    Pseudo solid-solid reactions, which proceed through gaseous intermediates are of considerable importance in metallurgy, such as the reduction of metal oxides with carbon and the segregation roasting of oxidic copper or nickel ores. A model for paired processes has been derived for describing in detail the reduction of ferrous oxide with carbon in various rate-controlling regimes. This model is characterized by two parameters, k1 and k2, which include the intrinsic chemical reaction rate constants, k1 and k2, the diffusion coefficient DAc1, and the mass transfer coefficients, hAm1 and hcm2: Analytic solutions have been obtained for eight extreme cases, and a series of numerical solutions obtained with the aid of an electronic computer are presented. A calculated example based on experimental data is included at the end of the paper.
    Flocculation of Kaolin Suspension by Isotactic-and Atactic-Poly (N-Propyl-2-Vinylpyridinium Bromide)
    Li Xiaodong, Zhang Banhua, Song Moudao and He Binglin Department of Chemistry Nankai University
    1983, 34(2):  116-126. 
    Abstract ( 527 )   PDF (516KB) ( 141 )  
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    Isotactic-and atactic-poly (N-propyl-2-vinylpyridinium bromide) QIP2VP and QAP2VP were used as flocculants for kaolin suspension. The effects of their molecular structures on flocculation were studied. The results are as follows: ( 1 ) The ability of flocculation of QAP2VP is better than that of QIP2VP. ( 2 )QAP2VP but not QIP2VP, Showed that the ability increased with increased molecular weight ( 3 )A low degree of quaternization is effective for the flocculation. ( 4 ) An abnormal phenomenon, which is considered as "Homocha-rge stabilization", was discovered at a certain concentration of flocculants ( 5 ) An equation between the experimental parameters was derived.
    Influence of Shot and Step Response on Parametric Sensitivity under the Stimulus-Response of Analysis
    S. Kaguei. N. Wakao Yu Qian Faculty of Engineering, Yokohama National University, Japan Shenyang Institute of Chemical Technology
    1983, 34(2):  127-136. 
    Abstract ( 614 )   PDF (377KB) ( 126 )  
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    Shot and Step response measurements were carried out with inert bed and adsorption bed both under isothermal conditions. Parameter values were determined from a time domain analysis of the measured input and response signals. Sensitivity test in the parameter values showed that shot response measurements may give more reliable parameter values than step measurements.
    A Computing Procedure for Multicomponent Distillation Design
    Gan Kuan and Zhuang yunming Shanghai Pharmaceutical Industry Design Institute
    1983, 34(2):  137-146. 
    Abstract ( 566 )   PDF (495KB) ( 416 )  
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    A rigorous computing procedure for multicomponent distillation design has been developed. In each iteration of the procedure, a simplified stage-to-stage calculation is followed by a rigorous operating calculation. The former calculates the equilibrium stages required for each tower section and the suitable feed stage locations, whereas the latter checks whether recoveries of key components are as required. In the stage-to-stage calculation and the operating calculation, the concept of the fractional theoretical stage is used by means of Murphree efficiency, thus the number of equilibrium stages is conceived as a continuous parameter. This treatment has the advantages of making the calculation converge precisely to the required recoveries of key components, reducing the computation work, and locating the suitable feed stages. By using a correlation developed from the Fenske equation, and based on the relevant data from operating calculation, the distribution of each component between distillate and bottomn and also total moles of products are obtained. If the required recoveries are not satisfied, a new iteration is performed together with the newly calculated vapor and liquid flow profiles. This procedure can be applied to conventional multicomponent distillation as well as multifeed complex distillation. It has been used for debutanizer, de-propanizer, acetic acid-formic acid-water tower, acetone-methanol-iso-propanol-water tower and acetone-chloroform-benzene tower. The number of iterations ranges from two to four.
    A Multistage Model with Reflux for Bubble Column
    Mo Zhiguang Research Laboratory of Chemical Engineering, South China Institute of Technology
    1983, 34(2):  147-155. 
    Abstract ( 556 )   PDF (457KB) ( 127 )  
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    A multistage model with liquid phase flowing through a series of equal cells with reflux and gas phase flowing through the same series of cells without reflux has been proposed. The concentration of the reacting gas component dissolved in the liquid at ith cell is assumed to be the mean of those at (i + l)th and (i-1)th cells. The concentrations in liquid and gas, and the gas flow rate along the height of column can be calculated stepwise. This model can be applied also to systems in which reaction may be non-first order, and the flow rate, composition and pressure of gas may be variables. This model has been applied to two small experimental bubble columns and the calculated results of the concentration profiles along the height of columns fit observed data fairly well.
    The Study for Some Physical and Chemical Properties of Trihydrated Magnesium Carbonateand its Hydrolytic Product ——Basic Magnesium Carbonate
    Hong Ruixiang, Ju Yilian, Chen Suqin and Xia Shupin Qinghai Institute of Saline Lake, Academia Sinica
    1983, 34(2):  156-161. 
    Abstract ( 911 )   PDF (344KB) ( 210 )  
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    This paper discussed some physical and chemical properties of trihydrated MgCO3 and its hydrolytic product-basic MgCO3 is obtained from NH4HCO3 reacting with MgCl2 solution. The trihydrated MgCO3 and basic MgCO3 are examined with differentia thermal gravimetric, differential thermal, infrared spectra and X-Ray diffraction analyses. Besides, we find out that the two molecules of crystal water in MgCO3·3H2O have different bonding abilities, that the structural formulae of MgCO3·3H2O and 3MgCO3·Mg (OH)2·4H2O are Mg(HCO3)(OH)·2H2O and Mg(HCO3) (OH)·Mg(OH)2·H2O respectively; and that the exothermic peak of basic MgCO3 at 515℃ has certain relationship with physical property of the product itself.
    A Model on Limiting Gas Velocities for Entrainment
    Jia Chenyan Shanghai Design Institue of Pharmaceutical Industry
    1983, 34(2):  162-172. 
    Abstract ( 481 )   PDF (517KB) ( 431 )  
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    A "Two region" model is proposed. By consider the discrimination of "re-gimes", drop size distribution, projection velocities of drops and variations of drag coefficients, an integration model is derived. It can reasonably explain the variations of limiting gas velocities with many facts, such as plate spacing, gas density, and liquid flow rate etc. After simulations and further simplifications, two simple equations are obtained. From tests with the data of various industrial plates and practical engineering design methods, the results are satisfactory, and the parameters obtained from fitting in with the data of industrial plates are in good agreement with those in the laboratory correlations from the literature.
    Extraction of Potassium, Rubidium and Cesium in Brine with Clinoptilolite Rock
    Kang Dingxue, Chen Xianman, Liu Ziqin, Wang Fengming Xing Yufang, Xiao Fuquan and Li Pincui Qinghai Institute of Salt Lake, Academia Sinica
    1983, 34(2):  173-183. 
    Abstract ( 685 )   PDF (508KB) ( 273 )  
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    The ion-exchange characteristics of the clinoptilolite rock in China for alkali metal ions, and the relations between the static exchange capacities and the radii of alkali metal ions have been studied. Under dynamic condition, the selective coeffients of the systems K+/Rb+, K+/Cs+and Rb+/Cs+were determined, and the separating properties of the system K+/Rb+/Cs+were investigated. Our studies reveal that it is possible to extract alkali metal ions by using clinoptilolite rock. We have also studied the separating conditions of K+, Rb+and Cs+in the concentrated salt solution of alkali metal produced in a factory. The results show that this clinoptilolite rock has good extracting characteristics and efficiency for alkali metal ions, and the technological process extracting rubidium salts and cesium salts has been worked out under experimental conditions.
    Hydrodynamic Characteristics in New Vertical Sieve Tray
    Xu Wuiqin and Shen Ziqiu Dalian Institute of Technology
    1983, 34(2):  184-193. 
    Abstract ( 644 )   PDF (473KB) ( 170 )  
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    Hydrodynamic characteristics of VST with different cap configurations were studied in a 500 × 370mm rectangular column and a circular column of φ1.2m with air-water system. The influences of various geometrical parameters and hydrodynamic conditions upon the pressure drops of trays, the upper and lower limits of allowable gas velocities and the amounts of the lifted liquid were examined. By discussing and analyzing the experimental results on the hydrodynamic view, we presented empirical correlations used for the hydro-dynamic design of the VST column. In order to minimize the pressure drop of the VST, a modified VST with the nozzle-type vapour riser was used. The experimental results showed that the pressure drops of the modified VST are 40% less than those of conventional VST operating under the same conditions.
    Expansion of Large Scale Fluidized Beds with Internals
    Chen Dabao, Zhao Lianzhong and Yang Guilin Institute of Coat Chemistry, Academia Sinica, Shanxi
    1983, 34(2):  195-200. 
    Abstract ( 638 )   PDF (246KB) ( 398 )  
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    The effect of horizontal internals, slant blade baffles and Screen on the expansion of the large-scale fluidized beds has been studied. Experiments were carried out using cylindrical beds 300, 500 and 1000mm in diameter. From experimental results, a correlation is reduced: where η = 2.33 for slant blade baffle and η=2.15 for screen. The author find that the critical diameter of fluidized bed with horizontal internals can be taken 0.3m.