JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 18 , Issue 6
Showing 1-15 articles out of 15 articles from the selected issue
  • YUJI SHINDO, TOSHIKATSU HAKUTA, HIROSHI YOSHITOME, HAKUAI INOUE
    1985 Volume 18 Issue 6 Pages 485-489
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    To investigate the separation of a multicomponent mixture by means of a microporous glass membrane, experiments in the separation of a ternary mixture composed of helium, oxygen and argon were performed with cocurrent flow operation at 407 K. The pressure of the feed stream was 175 kPa and 216 kPa, while the pressure of the permeate stream was maintained at atmospheric. The cut was made to vary by changes in feed-gas flow rate. Theoretical analysis was made on the basis of some assumptions. The agreement between theoretical values and experimental data for both permeated and rejected gas composition was fairly good. In addition, the effect of longitudinal mixing in both feed and permeate streams, and the usefulness and limitations of the model, were studied.
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  • FENG-HSIN HUANG, MENG-HUI LI, LLOYD L. LEE, KENNETH E. STARLING, FRANK ...
    1985 Volume 18 Issue 6 Pages 490-496
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    An equation of state for carbon dioxide is developed here that yields high accuracy in P-V-T calculations over wide ranges of temperatures (216-423 K) and pressures (to 310.3 MPa). It is particularly accurate around the critical region due to the use of "nonanalytical" terms to model the critical isotherm. Thus it is suited to applications in supercritical states. The density calculation is reliable to within 0.1-0.2 % outside the critical region, and to within 1% near the critical point. The equation has also been tested for vapor pressure and enthalpy calculations (with deviations less than 0.06 %, and 2-5 J/g, respectively). Comparison with a number of existing equations of state shows that the present equation is more dependable.
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  • MASABUMI NISHIKAWA, KAZUHIRO SHIINO, TAKASHI KAYAMA, SHIGERU NISHIOKA, ...
    1985 Volume 18 Issue 6 Pages 496-501
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Gas holdup, bubble size distribution and gas absorption capacity coefficient in a multi-stage gas-liquid spouted vessel are observed in this study and it is confirmed that coalescence of gas bubbles observed in the calm uniformflow section in a single-stage spouted vessel can be avoided by introduction of perforated plates.
    Experimental results show that effect of physical properties of liquid on the capacity coefficient in a spouted vessel is more similar to that observed in an aerated mixing vessel than to that of a bubbling column.
    It is also observed that the gas absorption coefficient is proportional to the square root of the Sauter mean bubble diameter.
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  • MOTOAKI ADACHI, KIKUO OKUYAMA, YASUO KOUSAKA
    1985 Volume 18 Issue 6 Pages 502-509
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The electrostatic dispersion of polydisperse aerosol particles carrying unipolar charge was studied theoretically and experimentally. The time-dependent behavior of polydisperse aerosols due to electrostatic dispersion in stationary air and a laminar pipe flow is evaluated by numerically integrating the "birth-death" equations for various conditions. The results are compared with those obtained from the well-known Wilson''s equation, which is derived for a monodisperse aerosol having uniform charge quantity in stationary air. The effects of particle size distribution, particle charge distribution, image force and flow conditions of aerosols on the aerosol behavior were studied. It was found that Wilson''s equation can roughly estimate the decrease in number concentration of polydisperse aerosols, if mean electrical mobility and geometric mean radius are used to take account of the effect of polydispersity of both charge and size. Some of the calculated results were in good agreement with the experimental results obtained in a closed chamber and in a laminar pipe flow.
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  • KENJI OKADA, YASUHARU AKAGI
    1985 Volume 18 Issue 6 Pages 509-514
    Published: December 20, 1985
    Released: April 19, 2006
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    Removal of oil droplets from an oil-in-water mixture was studied, using the method of coalescence through a packed bed. The coalescence behavior of oil droplets in the bed was observed photographically. It was shown that the separation efficiency was low until a layer of oil phase was formed in the bed, but after the oil layer was formed high separation efficiency was achieved. At steady state the relation between pressure drop and oil holdup in the bed was examined, and a method of estimating the amount of oil holdup in the bed from the measured pressure drop was developed. The effects of packing diameter, length of bed and liquid velocity on separation efficiency were examined experimentally, and the separation efficiency was correlated with these variables.
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  • TOSHIRO MARUYAMA, ZEN-ICHI YOSHIDA, SADAO MIKI
    1985 Volume 18 Issue 6 Pages 515-519
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    A new type of spinning catalyst basket reactor, referred to here as the annular reactor, has been developed in which an annular basket rotates in an unbaffled annular vessel. The distinctly superior performance of the annular reactor over existing reactors was confirmed by experiments in liquid-phase isomerization of quadricyclane to norbornadiene. It was found that the annular reactor increased the rate of mass transfer by a factor of about 4.5 compared with a Carberry reactor of similar dimensions. In addition, it needs a smaller liquid volume and less agitation power. For testing heterogeneous catalysts of high activity, the use of the newly-developed annular reactor is strongly recommended.
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  • HIROMOTO USUI, YUJI SANO
    1985 Volume 18 Issue 6 Pages 519-525
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The shear stress-shear rate behaviour of a thixotropic coal water mixture (CWM) was studied in coaxial rotating cylinder rheometer under a wide variety of rest and shear rate history. The transient stress data were used to construct equilibrium and constant-structure flow curves. These transient stress data, i.e. the stress relaxation data and the stress recovery data, were also used to evaluate the breakdown and buildup processes of the internal structure. A phenomenological thixotropy model which has the structural stress as a thixotropic structural parameter was proposed. This model can predict the thixotropic hysteresis loop precisely.
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  • KAZUYUKI SHIMIZU, MASAKAZU MATSUBARA
    1985 Volume 18 Issue 6 Pages 525-533
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    A singluar value analysis was carried out for the assessment of control structures of a distillation column. An analysis based on the IMC (Internal Model Control) structure shows that the material balance type of control structure is preferable to the conventional type and the ratio control type proposed by Ryscamp from the points of view of the sensitivity of the control quality to modeling errors and the size of the set point change which the closedloop system can handle for dual composition control.
    Several types of modeling errors which typically appear in the distillation system were characterized by the maximum singular values and the robustness of the multivariable Pi-control system was studied within the framework of singular value analysis.
    Computer simulations were carried out to illustrate the characteristics.
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  • HAJIME UNNO, TAKASHI AKEHATA
    1985 Volume 18 Issue 6 Pages 533-538
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The flow behavior of excess activated sludge containing highly concentrated organic solid, and showing an extremely thixotropic nature, was investigated.
    An experimental method for measuring the flow characteristics of the sludge under the condition of the same structure was proposed. By applying this method the relationship between shear rate and shear stress of a samestructure sludge was obtained, and it was found that the relationship was very similar to that of a plastic fluid. The relationship was named the sludge structure curve (SSC). SSC was degenerated into one curve by using a yield stress which was characteristic of each structure. This curve was named the sludge characteristic curve (SCC), because SCC was uniquely determined by the concentrations of solid and sludge conditioning agent, independently of sludge structure and temperature.
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  • TOSHIFUMI TSUJI, TAKAO MORI, MASAYUKI TANIGUCHI, KAZUYUKI SHIMIZU, TAK ...
    1985 Volume 18 Issue 6 Pages 539-544
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The color and pheophorbide content of green leaf protein concentrate (LPC) samples from white clover and alfalfa were affected by the conditions of heat coagulation. Extraction with organic solvents made it possible to remove the pigments, including pheophorbide, and fat from the green LPC samples. Of the organic solvents tested, ethanol was considered to be most suitable from the viewpoint of producing edible protein as well as its dissolving power for chlorophyll, the major pigment in plants. The optimum concentration of ethanol for chlorophyll extraction was around 90 %. The rate of extraction of chlorophyll was considerably dependent upon methods of drying green LPC samples. An equilibrium diagram of chlorophyll extraction with ethanol, based on the results of single extraction with fresh solvent, is presented.
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  • KOHEI OGAWA, CHIAKI KURODA, SHIRO YOSHIKAWA
    1985 Volume 18 Issue 6 Pages 544-549
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Assuming that the turbulent flow field consists of eddy-groups and that each of them has respective average frequency, a formula for the one-dimensional energy spectrum function (ESF) for wide wavenumber ranges is proposed by using the information entropy from the standpoint of statistical mechanics. The newly proposed formula appears to be a satisfactory approximation of past practical distributions of ESF even if the distribution has more than one order of wavenumber range to which the Kolmogoroff spectrum law can be applied. In addition, the relationship between micro and macro scale, the displacement of fluid particle, the turbulent eddy diffusivity and the points to be noted for scale-up of equipment are discussed on the basis of the newly proposed expression of the one-dimensional ESF.
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  • TATSUO NISHIMURA, YOSHIJI OHORI, YOSHIHIKO KAJIMOTO, YUJI KAWAMURA
    1985 Volume 18 Issue 6 Pages 550-555
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Mass transfer characteristics in a channel with symmetric wavy wall were investigated by the Leveque theory and the electrochemical method. The channel used has a geometry similar to that of the Oxford membrane blood oxygenator. The flow regime covered ranged from laminar to turbulent flow.
    The local Sherwood number distributions indicate that the reversed-flow region significantly differs from the forward-flow region in mass transfer characteristics. For laminar flow, mass transfer enhancement of the wavy channel is scarcely expected as compared with the corresponding straight channel, but is found to be remarkable for turbulent flow.
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  • SHIGEKI TAKISHIMA, SHOZABURO SAITO
    1985 Volume 18 Issue 6 Pages 555-561
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    An equation of state is derived from a group contribution model which takes into account the effect of local molecular distribution on potential energy in terms of the non-random two-liquid (NRTL) model. Model parameters for methyl and methylene groups are determined from the data reduction of saturated properties of n-alkanes. It is shown that the equation of state correlates well the saturated properties of "-alkanes and successfully predicts the vapor-liquid equilibria of n-alkane binary mixtures.
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  • HARUMI MATSUZAKI, MASAYOSHI KUBOTA, SANKICHI TAKAHASHI, KATSUYA EBARA, ...
    1985 Volume 18 Issue 6 Pages 561-564
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
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  • YASUZOU SAKAI, HAJIME UNNO, TAKASHI AKEHATA
    1985 Volume 18 Issue 6 Pages 564-566
    Published: December 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
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