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Table of Content
25 June 1957, Volume 8 Issue 1
    化工学报
    POLARIZATION AND CORROSION OF STEEL IN SOLUTIONS OF SODIUM PHOSPHATE ON PRESENCE OF CHLORIDE-ION
    Wu HAO-TSING, CHANG MIN-MIN (Department of Chemistry, Fu-Tan University)
    1957, 8(1):  1-8. 
    Abstract ( 561 )   PDF (535KB) ( 186 )  
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    The present work on polarization and corrosion of steel is undertaken to investigate the hydrogen overvoltage, cathodic and anodic polarization and corrosion of specimens in inhibited and noninhibited solutions. Hydrogen overvoltage-log current density relationships on specimens have been measured. The results are shown in Fig. 3, and for each current densitiey, the hydrogen overvoltage on the steel in 0.1 N HCl decreases as corrosion proceeds. But it increases markedly during the addition of sodium phosphate as inhibitor up to a concentration of 0.78.10-1 M which is believed to be an optimum concentration (Fig. 4). The anodic and cathodic polarization curves of the specimens in solu-tions of 0.1 N hydrochloric acid containing 1.0·10-1 M sodium phosphate with pH 8.6 and of 0.1 N alkalinized sodium chloride with same pH, are studied and compared. At current density 0.4 mA/cm2 the magnitude of △, the difference between steady state potential and potential of cathodic polarized electrode, in former solution is 577 mv greater than that in the later. The presence of sodium phosphate shifts the steady state potential in the anodic direction. There has been no change in weight, and no local corrosion could be detected by microscopic examination when steel specimens are exposed to this inhibited solution for fourteen days (Fig. 9, d). In solutions of lesser sodium phosphate concentration, corrosion be-havior of steel has been investigated. Although the passivation occurs in time-corrosion curves as shown in Fig. 8, microscopic examination still reveals local corrosion on its surface (Fig. 9, a, b). The extend to which corrosion is inhibited and the increase in △ are closely related, and run approximately parallel to each other.
    CALCULATION OF SATURATED LIQUID AND VAPOR DENSITIES IN THE TWO PHASES REGION
    CHU TZe-SHE (Peking Polytechnical Institute)
    1957, 8(1):  27-35. 
    Abstract ( 601 )   PDF (346KB) ( 182 )  
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    The method of calculation of saturated liquid density, based on the Hansons method, has been proved theoretically from Haggenmachers equation of state. A critical compressibility has been used as a parameter for dividing the compounds into groups to overcome the defeat of Hansons method. The error of Saturated liquid density, calculated by this method, was within 1%. In this paper, a method for calculation of Saturated vapor densities and mixture liquid densities and a generalized equation of heat of vapolyzation was also given. These results proved that the theorem of corresponding state, could be applied to two phases region.
    STUDY ON THE RATE AND THE COURSE OF THE REACTION BETWEEN CHLORINE GAS AND THE LIGNIN IN PLANT CELLULOSIC MATERIAL
    SHIEH HONG-CHUAN (Institute of Applied Chemistry, Academia Sinica)
    1957, 8(1):  36-50. 
    Abstract ( 681 )   PDF (582KB) ( 121 )  
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    The reaction rate between the gaseous chlorine and the lignin in plant cellulosic material under the conditions of the pulping process with chlorine is determined, and the course of the reaction discussed. The determination of the reaction rate is carried out by measuring at constant temperature the volume of chlorine gas absorbed by rice straw which has been pret-reated with dilute alkali. The results indicate that the course of the reaction may be analyzed into two parallel reactions: A rapid one, the rate of which resembles that of the second-order reaction with unequal initial concentrations, and a slow one, the rate of which resembles that of the second-order reaction with equal initial concentrations. The only difference is that the concen-trations applied in the general kinetic equations are replaced by the frac-tions of the reagents remained. Through the determination of the quantity of hydrochloric acid formed during the reaction it is possible to indicate that the rapid reaction is of substitution type and the slow one of oxidation. The relation between the reaction rate, the course of the reaction and the main conditions of the reaction such as the quantity of chlorine applied, the content of lignin in the cellulosic material and the reaction temperature may be represented by certain mathematical equations.
    HEAT TRANSFER IN PACKED BEDS-TEMPERATURE DISTRIBUTION
    CHU PAO-LIN, WANG HSUEH-SUNG (Institute of Petroleum, Academia Sinica)
    1957, 8(1):  51-72. 
    Abstract ( 586 )   PDF (996KB) ( 174 )  
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    An experimental investigation was made of temperature gradients in air streams being cooled while flowing through a cylinder of diameter 81 mm packed with high thermal conductivity (iron and copper) and low thermal conductivity solids of spheres, cylinders and Raschig rings. From the measured temperature gradients at various bed depths and radial posi-tions, and for the different particle sizes and flow rates, the effective thermal conductivity Ke, and the heat transfer coefficient of the wall hw, were determined by the integral, graphical and the direct-current electric analog methods. In the experimental range: Dp/Dt varied from 0.074 to 0.254 for the low thermal conductivity solids, from 0.12 to 0.2 for the high thermal con-ductivity solids; L/Dt varied from 5 to 15; Re number varied from 130 to 1400, corresponding to a linear velocity of 0.5- 1.6 meters per minute. If the arithmatic mean of the inlet and outlet temperatures was used as a qualitative temperature in the calculation, the effective thermal conductivity Ke, and heat transfer coefficient of the wall hw, could be correlated in the following equations: For low thermal conductivity solids: For high thermal conductivity solids: In case of cylinders and Raschig rings, the Dp in the above equations should be substituted by Dp and the constants 0.182 and 0.3 in the KG for- mulas should be changed to 0.22 and 0.38 correspondingly. A direct-current electric analog method was used in this paper, by which the temperature profiles of the bed could be calculated very con-veniently.
    THE APPLICATION OF PH TOMETRIC METHOD IN THE STUDY OF THE CONDENSATION EACTION OF p-NITROSOPHENOL & o-TOLUIDINE TO PRODUCE o-METHYL-INDOANILINE AND IN PRACTICAL PRODUCTION CONTROL
    1957, 8(1):  73-82. 
    Abstract ( 498 )   PDF (461KB) ( 100 )  
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    The kinetics of the condensation reaction of o-toluidine and p-nitro-sophenol to produce o-methyl-indoaniline, and the quantitative determina-tion of the latter have been studied photometrically. Attempt to determine the product by first converting it to its leuco form with excess reducing agent (SnCl2, Vitamine C) has been proved unsatisfactory, because the extent of excess of the reducing agent will notably affect the analytical results. It has been found from photometric data that the o-methyl-indoaniline itself is very stable in a solution of about 82% H2S04. If enough sulphuric acid of proper strength has been used to dilute the sample of reaction mass so as to stop the reaction almost instantaneously and completely, then the quantity of indoaniline present will not change with time. Meanwhile, samples of pure o-methyl-indoaniline and p-nitrosophenol have been prepared, and their characteristic absorption curves in 82% H2S04 solutions have been determined. It is found that: o-methyl-indo-aniline has a max. absorp. at 574 mμ, and its molar extinction coeff. is ∑_(574)~In= 2.44 × 104 (l.-mol-1 -cm-1), while p-nitrosophenol does not interfere at this wave lenth. At 428 mμ, the molar extinction coeff. of o-methyl-indoaniline is ∑_(428)~In= 2.27 ×103; of p-nitrosophenol is ∑_(428)~N.P.= 5.4 × 103. There-fore, it is possible to analyze individually these two components in a mi x-ture by measuring the light absorption at 574 & 428 mμ with a photometer. Depending upon these, the composition of successive samples of reaction mass has been analyzed photometrically, and its change with time has been recorded. The calculated values of the rate constant k and the energy of activation E have been found to be quite consistent with the data found in the literature. The variation of k values with the concentration of reaction medium (H2S04) has been found also consistent with those data. Therefore it has been proved possible to apply photometric method in analysis of o-methyl-indoaniline (and p-nitrosophenol) in the reaction, mass or in control of the production process. In applying this method to study the progress of the condensation reaction under practical production condi-tions, it is discovered that the amount of o-methyl-indoaniline present in the reaction mass steadily in creases to a maximum, and then begins to decreases. These points may be of some significance in the practical production.