JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 15 , Issue 4
Showing 1-16 articles out of 16 articles from the selected issue
  • TAKUO SHIGETOMI, TOMOSHIGE NITTA, TAKASHI KATAYAMA
    1982 Volume 15 Issue 4 Pages 249-254
    Published: August 20, 1982
    Released: April 04, 2006
    JOURNALS FREE ACCESS
    An adsorption model combining localized and nonlocalized adsorptions is presented to interpret the adsorption isotherms of water and methanol in zeolitic sorbents of type A. The Langmoir equation is used for the localized adsorption of water and the van der-Waals-type equation is suggested for nonlocalized adsorption. For methanol adsorption the extended form of the Langmuir equation based upon the model in which one molecule occupies two adjacent sites, plays a significant role. Single-component adsorptions of water and methanol on Molecular Sieve 4A are represented fairly well by means of two adjustable parameters, an adsorption equilibrium constant and a physical interaction parameter. The theory can predict the selective adsorption of water from aqueous methanol solutions without any adjustable parameters.
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  • KUNIO KATAOKA, HITOSHI MATSUO, HIROYUKI SHUNDOH
    1982 Volume 15 Issue 4 Pages 255-261
    Published: August 20, 1982
    Released: April 04, 2006
    JOURNALS FREE ACCESS
    A generalized eddy transfer coefficient model has been experimentally obtained for axisymmetric, nonisothermal variable-density jets, the initial density ratio of which ranges from 0.66 to 5.1. The local variation in the dynamic eddy transfer coefficients for momentum and heat has been measured in the developed region: both transfer coefficients on the jet axis are proportional to the square root of the initial density ratio, but are almost independent of the axial distance from the nozzle exit; the transfer coefficients for momentum and a chemical species remain constant in the inner region whereas the transfer coefficient for heat decreases slightly with increasing radial distance; all the transfer coefficients decrease rapidly in the outer region owing to the intermittent entrainment of the quiescent ambient fluid. The present model can perdict local values of the transfer coefficients over the range of initial density ratio from 0.66 to 5.1 if the initial jet condition alone is specified at a nozzle exit.
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  • TATSUO KANKI, SATORU IUCHI, YOSHINORI MATSUI, YUJI YAMAMOTO
    1982 Volume 15 Issue 4 Pages 261-267
    Published: August 20, 1982
    Released: April 04, 2006
    JOURNALS FREE ACCESS
    A new, explicit equation for nononiforni pressure diffusion of a ternary gas mixture in a circular tube is obtained. The theory employed is based on the authors'' existing kinetic model of foursided local velocity distributions. The diffusion equation shows that transport of the individual components is expressed by a simple summation of two separated terms of diffusional and hydrodynamic flows. Validity of the equation is shown by comparison of the fluxes with those measured for a He-Ne-Ar mixture through a diffusion bridge. The diffusion equation gives a physical explanation for striking phenomena at low pressures, such as Hoogschagen''s nonequimolar counter-diffusion at a uniform pressure, diffusio-molecular pressure effect, velocity slip at the channel wall, and Knudsen''s minimum in volume flow.
    The concept of "diffusional momentum slip" is newly proposed. Use of this concept is effective in deriving the solutions to transport of gases at low pressures directly from the continuum theory.
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  • HITOSHI KOSUGE, KOICHI ASANO
    1982 Volume 15 Issue 4 Pages 268-273
    Published: August 20, 1982
    Released: April 04, 2006
    JOURNALS FREE ACCESS
    Experimental study of vapor-phase sensible heat and mass fluxes in ternary distillation of the methanol-ethanol-water system was made with a wetted-wall column at total reflux conditions.
    From heat and mass balances for the liquid film, a theoretical expression was derived for the interfacial velocity caused by mass fluxes. The interfacial velocity was shown to be a function of the sensible heat and diffusion fluxes.
    Observed vapor-phase sensible heat fluxes showed good agreement with the theoretical values obtained by laminar flow theories. Observed vapor-phase diffusion fluxes obtained from mass flux measurements also showed good agreement with the theoretical values, but a poor correlation was obtained for vapor-phase mass fluxes. Observed interfacial velocities were compared with the calculated values.
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  • FUMIYUKI NAKASHIO, KAZUO KONDO, AKINORI MURAKAMI, YOSHIRO AKIYOSHI
    1982 Volume 15 Issue 4 Pages 274-279
    Published: August 20, 1982
    Released: April 04, 2006
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    Measurements of the extraction equilibria of copper and zinc with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester dissolved in w-heptane or toluene diluent were carried out at 303 K.
    It was found that the extractant (HR) is apt to dimerize in n-heptane diluent. It was clarified that copper and zinc are extracted according to the following equations, respectively, in the low concentration range of the metals.
    Cu2+aq+2(HR)2, org⇔CuR2•2HRorg+2H+aq
    Zn2+aq+1.5(HR)2, org⇔ZnR2•HRorg+2H+aq
    Extraction equilibrium constants, Ke, Cu = 1.0×10-4 and Ke, Zn=2.5×10-2 mol1/2/dm3/2 were obtained. From the above experimental results, it is seen that selective separation of copper and zinc is possible by solvent extraction with the extractant used in this study.
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  • MOTOYUKI SUZUKI, AKIYOSHI SAKODA
    1982 Volume 15 Issue 4 Pages 279-285
    Published: August 20, 1982
    Released: April 04, 2006
    JOURNALS FREE ACCESS
    The Dubinin-Astakhov (D-A) equation is modified for adosrption of gases on microporous activated carbons with appreciable size distribution of micropores.
    Parameters n and E involved in the D-A equation are assumed to vary with the ratio of micropore size to molecular size of adsorbate. Also, E is considered to be in proportion to the standard heat of vaporization of the adsorbate. The dependence of n and E on these characteristics is determined from adsorption data for carbon molecular sieves that have uniform micropores. Thus, once the size distribution function of micropores is given for a commercial activated carbon, adsorption equilibrium of any gas is predictable with the generalized D-A equation proposed here by accounting for the micropore size distribution.
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  • ULRICH HAUPTMANNS, JAVIER YLLERA, HERMINIO SASTRE
    1982 Volume 15 Issue 4 Pages 286-291
    Published: August 20, 1982
    Released: April 04, 2006
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    The principal mechanisms leading to an explosion of the reactors in a plant for production of nitric acid are represented by means of a fault tree whose numerical evaluation reveals weak points of the safety system and allows its improvement. Both mean values and log-normally distributed failure rates are used, the latter allowing assessment of the influence of the uncertainty of input data on the result for the unreliability of the system.
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  • KENICHI USHIKI, EIICHI NISHIZAWA, HISAO BENIKO, KOICHI IINOYA
    1982 Volume 15 Issue 4 Pages 292-298
    Published: August 20, 1982
    Released: April 04, 2006
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    The performance and separation mechanism of mist separators, which consist of multi-stage rows of narrow flat plates, are experimentally studied. The effects of stages, blade inclination angle, air velocity, blade pitch and lateral blade dislocation on partial collection efficiencies and on pressure loss are described. The beat design has 30° blade inclination angle and 5 to 7 stages, under conditions of constant pressure loss and of constant blade pitch.
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  • Ko HIGASHITANI, RYUJI OGAWA, GIJIRO HOSOKAWA, YOSHIZO MATSUNO
    1982 Volume 15 Issue 4 Pages 299-304
    Published: August 20, 1982
    Released: April 04, 2006
    JOURNALS FREE ACCESS
    The coagulation of colloidal particles in a simple shear flow of a viscous fluid is considered. The coagulation rate between unequal spherical particles is calculated by use of approximate trajectory equations, and a kinetic equation of shear coagulation is proposed in which the hydrodynamic interaction between particles is taken into account. It is found that the coagulation rate decreases rapidly with increase of the ratio of particles radius ai/aj and a dimensionless quantity 6πμa3ijγ/A. Comparison between the present theory and the classical Smoluchowski theory indicates that the Smoluchowski theory is applicable to limited coagulation systems and that it overestimates the coagulation rate considerably when applied to common aqueous dispersions. It is also found that the change of particle concentration is conveniently estimated by a kinetic equation in which the coagulation rate between unequal particles is approximated by that between equal spheres.
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  • HIROYASU SEKO, SETSUJI TONE, TSUTAO OTAKE
    1982 Volume 15 Issue 4 Pages 305-310
    Published: August 20, 1982
    Released: April 04, 2006
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    Necessary and sufficient conditions for existence of steady states are derived from a mathematical model of fluid catalytic cracker (FCC), and sufficient conditions for stable steady states are determined from the Hurwitz stability criterion by using a linearized FCC model. Based on the graphical analysis of these conditions in a three-dimensional coordinate, a criterion for stability and multiplicity of steady states is developed. By applying the criterion to three kinds of chemical reaction types in the FCC, the stability of steady states can be successfully predicted under various operating conditions.
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  • HIROYASU OHASHI, TAKUO SUGAWARA, KEN-ICHI KIKUCHI, MORITO TAKEDA
    1982 Volume 15 Issue 4 Pages 311-313
    Published: August 20, 1982
    Released: April 04, 2006
    JOURNALS FREE ACCESS
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  • IKUHO YAMADA, Soo GAK LEE, SETSURO HIRAOKA, SHIGEHIKO SUDA, MASAO UCHI ...
    1982 Volume 15 Issue 4 Pages 313-316
    Published: August 20, 1982
    Released: April 04, 2006
    JOURNALS FREE ACCESS
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  • KENJI FUKUCHI, SHIGETOSHI KOBUCHI, YASUHIKO ARAI
    1982 Volume 15 Issue 4 Pages 316-318
    Published: August 20, 1982
    Released: April 04, 2006
    JOURNALS FREE ACCESS
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  • TATSUYA OKAZAKI, HIROMU HAYASHI, Em KAWANISHI, YOSHIAKI KONISHI
    1982 Volume 15 Issue 4 Pages 318-320
    Published: August 20, 1982
    Released: April 04, 2006
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  • HIROMITSU KOJIMA, KOICHI ASANO
    1982 Volume 15 Issue 4 Pages 321-323
    Published: August 20, 1982
    Released: April 04, 2006
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  • EIICHI ABE, HIDEHARU HIROSUE
    1982 Volume 15 Issue 4 Pages 323-326
    Published: August 20, 1982
    Released: April 04, 2006
    JOURNALS FREE ACCESS
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