JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Online ISSN : 1881-1299
Print ISSN : 0021-9592
Volume 12, Issue 2
Displaying 1-17 of 17 articles from this issue
  • YOSHIKI UNNO, DAISUKE HOSHINO, KUNIO NAGAHAMA, MITSUHO HIRATA
    1979 Volume 12 Issue 2 Pages 81-85
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
    A new algorithm, based on the solution of groups model, is proposed to predict liquid-phase activity coefficients. This method is not an extension of the so-called ASOG model but is rather a simple application of the solution of groups model. The molecular activity coefficients of solid-liquid equilibria were calculated directly from the correlated vapor-liquid equilibria of the other component pairs, which consisted of the same group as solid-liquid equilibria. This method was successfully used for predicting the solid-liquid equilibria of binary systems which included naphthalene as one component.
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  • FLOW RATE PREDICTION OF TURBULENT TWO-PHASE JET THROUGH AN ORIFICE
    TAKESHI SAKAI, MASAO KURODA, MASAHIRO SAITO
    1979 Volume 12 Issue 2 Pages 86-90
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
    The internal mixing twin-fluid atomizer, used in many industries, is a sort of twin-fluid atomizer which disintegrates liquid in the atmosphere after mixing liquid and gas within a mixing chamber. However, few investigations of the atomizer having a throat or an orifice port and a mixing chamber have been reported.
    In this paper, the discharge coefficient of this type of atomizer is investigted experimentally. The gas-liquid two-phase mixture was treated as a compressible and homogeneous fluid, and the critical pressure Pc and the acoustic velocity were taken into consideration to determine the discharge coefficient.
    Two empirical formulas of the discharge coefficient C0 were obtained for the gas-liquid two-phase jet, as follows:
    (a) Pc<1 Kg/cm2 (subsonic region)
    C0=0.38×10-3m0.466(D2/D1)-0.964Re0.983lw)0.984
    (b) Pc>Kg/cm2 (supersonic region)
    C0=0.593×m0.063(D2/D1)-0.048RE0.078lw)0.115
    Here, the experimental region is Wl=33-180 kg/hr, m=0.001-0.23.
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  • RYUZO ITO, YUSHI HIRATA, JUNICHIRO IKEDA, NOBUYUKI IMAMURA, KEI SAKATA
    1979 Volume 12 Issue 2 Pages 91-97
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
    The velocity profile and pressure gradient of turbulent flow in a porous pipe were measured at inlet Reynolds numbers of (1.01, 2.09, 3.08)×104 and ratios of injection/suction velocity to inlet average velocity of (-7.8 to 3.9)×10-3. From the similarity of velocity profile, the maximum velocity, the radial position having average velocity and the axial momentum flux have been examined, and the eddy diffusivity and the mixing length have been obtained. Variation of the friction factor was smaller than predicted by the film theory.
    The eddy diffusivity and the mixing length in the core region have been correlated into the same form asin the case without injection/suction by introducing defect parameters as
    E(r/R)=(εM/ν)(u+max-1/√Cf/2)(r/R)(τw/τ)/R+
    L(r/R)=(l/R)(u+max-1/√Cf/2)√(r/R)(τw/τ)
    and
    E(r/R)=L(r/R)√r/R
    The pressure gradient and the local values of velocity, eddy diffusivity and mixing length can be estimated from the correlations obtained.
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  • KOZO KOIDE, SHIGEHARU MOROOKA, KOREKAZU UEYAMA, AKINORI MATSUURA, FUKU ...
    1979 Volume 12 Issue 2 Pages 98-104
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
    Experimental work was conducted with a 550 cm-diameter bubble column to find the influence of column diameter on circulating liquid flow, gas holdup, bubble size and bubble velocity.
    The relationship between average gas holdup and superficial gas velocity in the column is almost the same as that in a small-size bubble column.
    When comparing the bubble velocity observed with the results of past experiments, it becomes clear that no particularly unusual phenomenon due to the large scale of the column exists in the circulating flow.
    Bubble sizes obtained by means of the electric resistivity probe method are larger than those measured in past experiments in small-size bubble columns. The reason for this difference is discussed briefly.
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  • HIROSHI KATAOKA, HIROSHI TAKEUCHI, KATSUMI NAKAO, HIDEHARU YAGI, TEIRI ...
    1979 Volume 12 Issue 2 Pages 105-110
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
    Values of the liquid-phase volumetric coefficient of mass transfer kLa in a large bubble column, 550 cm in diameter and 700 cm in liquid depth, were obtained from experimental data for carbon dioxide desorption from water, on the assumptions of perfect mixing in the liquid phase and piston flow or perfect mixing in the gas phase.
    The liquid-phase mass transfer coefficient kL was separated from kLa, using the data10) on gas holdup and the bubble diameter obtained with the same column. Values of kLa were in good agreement with a previous correlation1) based on data with small bubble columns, provided that perfect mixing was assumed for both gas and liquid phases. Values of kL ranged from 0.01 to 0.05 cm per second and were not affected appreciably by column size. The relationship between kL and bubble diameter was roughly similar to that in small columns, although bubbles in the present experiments were somewhat larger than in small columns.
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  • Eizo SADA, HIDEHIRO KUMAZAWA, MUHAMMAD ARIF BUTT
    1979 Volume 12 Issue 2 Pages 111-117
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
    The absorption rate of lean SO2 and/or NO2 into aqueous slurries of fine Ca(OH)2 or Mg(OH)2 particles was measured using a stirred vessel with a plain gas-liquid interface at 25°C and 1 atm. The absorption process of lean SO2 into Ca(OH)2 slurries was found to be almost gas-film controlled under the partial pressures considered here. On the other hand, for SO2-Mg(OH)2 slurry system, the diffusion of the reactant across the liquid film was significant and the absorption rate was increased with solid concentration. The observed enhancement factors were compared with the theoretical prediction according to the previously proposed model to estimate the dimensionless parameter concerning solid dissolution. For NO2-slurry system, the reaction between NO2 and the aqueous slurry may satisfactorily be considered the reaction between NO2 and water. The hydrolysis was found to be second-order in NO2 and the secondorder rate constant was derived as 5.0×107 l/mol•sec. The absorption rate of NO2 with coexistence of SO2 into aqueous slurries of Mg(OH)2 greatly exceeded that of NO2 alone into clear solutions with the same sulfite concentrations, which may be due to the solid-surface reaction in a region from the interface to the reaction plane.
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  • MAW-LING WANG, BARRY LEE YANG
    1979 Volume 12 Issue 2 Pages 118-124
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
    The geometric stability of a cylindrical particle undergoing radial growth in a supersaturated solution is studied by employing the time-dependent diffusion equations. In this paper, the perturbation technique is used to investigate the stability of shape. The perturbations in θ-and z-directions are both considered. The stability region for considering perturbation in z-direction is a special case of that for considering perturbation in θ- and z-directions. It was found that the stability boundary in the absolute sense and in the relative sense depends upon the growth of the moving solid-liquid interface and the degree of supersaturation.
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  • MASAKUNI MATSUOKA
    1979 Volume 12 Issue 2 Pages 125-129
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
    Normal freezing of the simple eutectic-forming system naphthalene-benzoic acid was carried out to investigate nonequilibrium separation phenomena. The growing interface was found to be concave under various conditions. The impurity concentration was found to be distributed not only axially but also radially in the ingot with noticeable concentration at the center. This fact was explained by assuming a distribution of temperature and impurity concentration of the melt on the growing interface. That is, solidification at the center must proceed at a lower temperature from a less pure melt which results in more trapping of the melt; thus the impurityrich solid will be formed at the center.
    On the basis of the experimental results, an effective scheme for separation by normal freezing was demonstrated to provide a purer product in a short operating time.
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  • YOSHIO NAKANO, MASARU ISHIDA, TAKASHI SHIRAI
    1979 Volume 12 Issue 2 Pages 130-136
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
    A procedure to predict macroscopic characteristics of solid-gas reactions on the basis of microscopic information on the reactivity of the powders composing the solid and the structure coefficients for gaseous transfer was proposed and applied to the reduction of an iron-oxide powder bed by hydrogen. This reaction example was consecutive and consisted of three stoichiometric reactions (Fe2O3→Fe3O4, Fe3O4→Fe1-y1O, and Fe1-y2O→Fe) and a nonstoichiometric reaction (continuous decrease in y of Fe1-yO).
    Profiles of the fractional reduction, gaseous reactant concentration, and variation in pressure within the bed during the reaction were computed and compared with the experimental results. The width of the zone of each reaction, which cannot be predicted by the conventional unreactedcore shrinking model, was also demonstrated.
    It was also found that the equilibrium hydrogen concentration for the reactions in the wustite range and wustite to iron became apparently high due to very slow change in the gas composition in the bed.
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  • YASUO HOSONO, KOICHI FUJIE, HIROSHI KUBOTA
    1979 Volume 12 Issue 2 Pages 136-142
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
    The deep shaft has been recently developed as an aeration device to meet high oxygen demand in liquid. The authors reported previously on the result of analyzing operational characteristics of the air-lift type deep shaft aerator.
    A similar analysis was carried out for the liquid-pump type shaft, in which liquid circulation between the downcomer and the riser parts in the shaft is maintained by a liquid pump.
    As results of the mathematical model simulation, the operating condition which gives a stable liquid circulation, and the optimal power economy condition, which yields the maximum capability of oxygen transfer to liquid per unit power consumption, are made clear. Though the power economy is a little lower than that in the air-lift type shaft, more flexible and stable operations can be expected with the liquid-pump type shaft under varying conditions of oxygen demand in liquid.
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  • TAKUO SUGAWARA, KOHTA OMORI, HIROYASU OHASHI
    1979 Volume 12 Issue 2 Pages 143-147
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
    The photolysis of aqueous potassium trioxalatoferrate(III) solution containing o-phenanthroline was conducted in plate-type batch and laminar flow photoreactors by irradiation from fluorescent lamps. The internal light filtering effect of a product on reactor performance was evaluated by the polychromatic diffuse light model (PDL-Model) which takes into account the polychromatic and diffuse characteristics of the lamp, the extent of internal light filtering, the diffusion rates of a reactant and a product, and the parabolic velocity distribution in the flow reactor.
    In the low internal light filtering region, the model reduced to the monochromatic parallel light model (MPL-Model) with mean molar absorption coefficient of product, which simulated experimental results well. In the high inner filter region, however, only the PDL-Model was applicable.
    Preliminary evaluation of the internal light filtering effect was made with a plate-type batch reactor containing reactants at extremely low concentration, to which a vessel containing the product solution was attached.
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  • TOSHIFUMI ISHIKURA, ISAMU TANAKA, HISASHI SHINOHARA
    1979 Volume 12 Issue 2 Pages 148-151
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
    Elutriation rate coefficient k'' was experimentally studied for the spouted bed (θ=60°) and the fluidized bed.
    The effects of various particles and operating conditions on elutriation were examined and an empirical correlated equation was obtained with a deviation within ±20%.
    It was found that the elutriation of fines was closely related to the length of particles bed L.
    The difference of elutriation rate coefficient k'' in this work and k proposed by Hercules et al.4) was investigated by considering the particles concentration distribution in bed, and it was recognized that k'' was better than k, considering the mechanism of the elutriation rate.
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  • YASUO KOUSAKA, KIKUO OKUYAMA, ATSUYOSHI SHIMIZU, TETSUO YOSHIDA
    1979 Volume 12 Issue 2 Pages 152-159
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
    Possible dispersion mechanisms of aggregate particles in air stream were proposed and their contribution to dispersion was studied by analyzing the dispersion forces. Various typical dispersers were tested to observe the change in size distribution and some of the theoretical analyses were verified. Impact of particles on some obstacles in air stream and acceleration or deceleration of irregular-shaped aggregates were found as a result, to be effective in aggregate dispersion.
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  • THEIR AZEOTROPIC RANGES AND SOME PREDICTED TERNARY AZEOTROPES
    ZDZISLAW M. KURTYKA, ELIZABETH A. KURTYKA
    1979 Volume 12 Issue 2 Pages 159-161
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
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  • MOMPEI SHIRATO, TSUTOMU ARAGAKI, EIJI IRITANI
    1979 Volume 12 Issue 2 Pages 162-164
    Published: April 20, 1979
    Released on J-STAGE: April 03, 2006
    JOURNAL FREE ACCESS
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  • KOHEI OGAWA, SHIRO ITO, HIDEHARU KISHINO
    1979 Volume 12 Issue 2 Pages 165b-166
    Published: April 20, 1979
    Released on J-STAGE: April 04, 2006
    JOURNAL FREE ACCESS
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  • R. J. WAKEMAN
    1979 Volume 12 Issue 2 Pages 165a
    Published: April 20, 1979
    Released on J-STAGE: April 04, 2006
    JOURNAL FREE ACCESS
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