JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 14 , Issue 2
Showing 1-16 articles out of 16 articles from the selected issue
  • JUN-ICHI KAWABATA, MIDORI YUMIYAMA, YONESHIRO TAZAKI, SENJI HONMA, TAD ...
    1981 Volume 14 Issue 2 Pages 85-89
    Published: April 20, 1981
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    The behaviour of silica sand particles with mean sizes 0.3, 0.45 and 0.6 mm fluidised by air under pressures from 0.1 to 0.8 MPa was observed in a transparent two-dimensional bed. Minimum fluidisation velocity, bed expansion and bed height fluctuation were measured by the usual methods, bubble characteristics such as the size, rising velocity and frequency by cine-photography.
    The minimum fluidisation velocity decreased with pressure, explainable by considering the increase of the turbulent flow contribution to bed pressure drop, and fairly well described by the Wen and Yu correlation. No virtual effect of pressure on bubble size was observed but bubble shape became flattened, which in turn accompanied a decrease in the bubble rise velocity. Based on these results, the increased bed expansion and the unchanged bed fluctuation could be consistently explained.
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  • HO-MING YEH, SHAU-WEI TSAI
    1981 Volume 14 Issue 2 Pages 90-97
    Published: April 20, 1981
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    The separation efficiency of rotated concentric-tube thermal diffusion columns with helical plane inserted as a spacer in the annulus was investigated with consideration of the curvature effect. It was found that the cascading effect could be effectively improved by rotating the tubes oppositely, while the remixing effect could be effectively reduced by employing a helical plane as a spacer, thereby leading to improved separation. Considerable improvement in separation was obtained by employing such column operating at the best tube-speed of rotation and the best wrapped angle of helical plane instead of using the stationary column without a helical plane. The equations for determination of the best value of wall distance and the highest separation in a batch-operated empty double-tube column were also derived.
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  • TADAE YAMANAKA
    1981 Volume 14 Issue 2 Pages 98-104
    Published: April 20, 1981
    Released: April 03, 2006
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    A compact analytical expression is obtained for the asymptotic overall mass or heat transfer coefficient in double flow mass or heat exchanger systems. The analysis is based on the integral equation for the trans-wall flux. The solution obtained in this paper is shown to be equivalent to one of the generalized eigenvalue problems proposed by Nunge, Gill and Blanco. Moreover the characteristic equation derived in the asymptotic analysis determines the eigenvalue spectrum of the mutual boundary value problem. This method can be similarly applied to co-current and counter-current systems. Various velocity profiles including non-Newtonian flows can be treated by the series expansion method.
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  • TETSUJIRO MITANI, YOICHI TAKASHIMA
    1981 Volume 14 Issue 2 Pages 105-111
    Published: April 20, 1981
    Released: April 03, 2006
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    To have some phenomenological and fundamental information on the desublimation processes in an annular-tube cold trap to be operated with a closed system at such low pressures that the Navier-Stokes equations may not be valid, we made experimental studies on the desublimation processes of naphthalene vapor in stationary nitrogen gas.
    It was found that the desublimation process consisted of an initial transient period and a subsequent quasi-steady period. Because the latter should be important for the design of the cold trap, under the quasi-steady period, we estimated three characteristic quantities such as the local desublimation rate, the apparent density and the reference length of desublimated solid layer. The effects of operating conditions on these quantities were studied by means of new dimensionless parameters, Ma and Pe which were induced from our theoretical development based on Maxwell''s moment method. It was found that the desublimation process in the transition region depended strongly upon Ma but scarcely upon Pe.
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  • MASAAKI TERAMOTO, YOSHIHIRO SUGIMOTO, YASUHIRO FUKUI, HIROSHI TERANISH ...
    1981 Volume 14 Issue 2 Pages 111-115
    Published: April 20, 1981
    Released: April 03, 2006
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    Oxidation of cyanide with ozone was carried out using a semi-continuous bubble column and a continuous bubble column. It was found that the overall reaction rate was strongly controlled by liquid-film mass transfer resistance. The observed rate was satisfactorily explained by the theory of gas absorption with chemical reactions if the intrinsic rate expressions of self-decomposition of ozone and the ozone oxidation of cyanide which had been obtained by the present authors were applied to the theoretical equations.
    A method for evaluating capacity coefficient of liquid-phase mass transfer from the absorption rate of ozone into water of high pH is also presented.
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  • KATSUTOSHI INOUE, HIRONORI AMANO, YUJI TOMIMOTO, MITSUHIRO YAMAMOTO, I ...
    1981 Volume 14 Issue 2 Pages 116-121
    Published: April 20, 1981
    Released: April 03, 2006
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    The extraction kinetics of copper from aqueous ammonium nitrate-ammonia mixture with n-hexane solution of Versatic acid was studied by the single-drop method. The change of extraction rate with concentrations of reactant species, such as copper and hydrogen ions in the continuous phase and Versatic acid in the dispersed phase, respectively, was studied for drop-formation and drop-rise periods.
    It became clear that the extraction rates during both periods were controlled only by the heterogeneous complex-forming reaction at the drop surface.
    The heterogeneous reaction rate was found to be proportional to the concentration of copper ion in the aqueous phase, inversely proportional to that of hydrogen ion and independent of that of Versatic acid in the dispersed phase. From the dependency of the reaction rate on the concentration of each reactant species and from the experimental results on the interfacial adsorption properties of Versatic acid, the rate-controlling step of this complex-forming reaction at the drop surface is considered to be as follows.
    Cu2+aq.+R-ad.Cu+ad.
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  • MASAAKI TERAMOTO, HIROSHI TAKIHANA, MICHIRU SHIBUTANI, TAKAHIRO YUASA, ...
    1981 Volume 14 Issue 2 Pages 122-128
    Published: April 20, 1981
    Released: April 03, 2006
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    A mass transfer model for the extraction of amine in W/O/W emulsion systems having internal aqueous HCl solution phase is presented which takes into account the diffusion in W/O emulsion drops as well as the external mass transfer around W/O emulsion drops, and the effect of various parameters on the extraction rate is clarified. Experimental data on the extraction of aniline, p-and m-toluidine by W/O/W emulsion systems using a batch-type agitation vessel is discussed on the basis of the present model. It is found that the model can explain the tendency of the experimental data. The mass transfer mechanism in W/O emulsion drops is discussed on the basis of the experimentally evaluated value of effective diffusivity in W/O emulsion drops.
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  • MASASHI ASAEDA, JIRO WATANABE, MASAMITSU KITAMOTO
    1981 Volume 14 Issue 2 Pages 129-135
    Published: April 20, 1981
    Released: April 03, 2006
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    In the unsteady-state or dynamic methods of determining transfer properties of gases in porous media, a simplified isobaric diffusion rate equation of the Fick''s type has been used even for some cases with a pulse of pure gas. By measuring the pressure response at one end of a single porous pellet accompanied by a stepwise change in gas concentration at the other end, however, it is shown that a relatively large and rapid pressure gradient appears in the porous pellet.
    The pressure response curves are analyzed theoretically by using non-isobaric rate equations to obtain good accord between the theoretical and observed results. The effects of the appearance of the total pressure gradient on the concentration change at the pellet end and on the diffusion rate are discussed in detail.
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  • HAJIME TAMON, SUSUMU KYOTANI, HIROYUKI WADA, MORIO OKAZAKI, RYOZO TOEI
    1981 Volume 14 Issue 2 Pages 136-141
    Published: April 20, 1981
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    Surface flow of hydrocarbons, such as ethylene, propylene and isobutane, through activated alumina at 10°C and 30°C is measured over a mean pressure level range of a few kPa to about 100kPa using a permeation apparatus. The surface flow coefficient is also determined as a function of amount adsorbed and temperature. The dependence of the surface flow coefficient on the above quantities can be well correlated using the random hopping model previously proposed by the authors. In addition, data from the literature for three other systems are correlated by this model.
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  • SATOSHI OKUDA, Woo SIK CHOI
    1981 Volume 14 Issue 2 Pages 142-148
    Published: April 20, 1981
    Released: April 03, 2006
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    This paper is concerned with the fracture characteristics of a spherical particle of nylon 6 when the particle, accelerated by an air gun, is impacted on various wedge-shaped targets having wedge angles of 180°, 150°, 120v, 90°, 70°, 50°, and 30°, respectively.
    The impact velocity and rebound velocity, deformation, and impact force of a particle are measured and an instantaneous photograph of fracture is also taken.
    The maximum impact force measured at the impact velocity where the impact particle begins to be fractured can be formulated as a power law with respect to the wedge angle of the wedge target, and the value of the exponent is about 2.3 over the ranges of wedge angle from 30° to 180°, that is, the flat target.
    It is found that there is an optimum wedge angle of the wedge target for cutting/grinding from the energy efficiency for grinding, and the optimum wedge angle of cutting tool may be estimated to be 70°-90°.
    From the total energy balance of the impact particle and the flat target, the value of the specific fracture-surface energy is also estimated to be 10.1-10.3 kJ/m2 at the optimum impact velocity of 130 m/s where the grinding efficiency is most favorable.
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  • SATOSHI OKUDA, Woo SIK CHOI
    1981 Volume 14 Issue 2 Pages 149-153
    Published: April 20, 1981
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    The mechanism of cutting fracture of a polypropylene (PP) is investigated by an experimental approach in which a PP particle accelerated by an axially symmetrical nozzle collides repeatedly with a wedge-shaped target. This experimental approach is useful in comminuting a polymeric material having viscoelastic properties such as those of PP.
    The mechanism of impact cutting fracture is examined mainly on the basis of the relation between the increase of specific surface area, the cutting probability, and the cumulative specific kinetic energy of the particle. The increase of specific surface area can be formulated by a power law in terms of the product of the cutting probability and the cumulative specific energy, and the value of its exponent is estimated to be 0.8 within this experimental range.
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  • M. A. SOLIMAN
    1981 Volume 14 Issue 2 Pages 154-155
    Published: April 20, 1981
    Released: April 03, 2006
    JOURNALS FREE ACCESS
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  • KOJIRO OGIWARA, YASUHIKO ARAI, SHOZABURO SAITO
    1981 Volume 14 Issue 2 Pages 156-158
    Published: April 20, 1981
    Released: April 03, 2006
    JOURNALS FREE ACCESS
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  • CHIAKI KURODA, KOHEI OGAWA, ICHIRO INOUE
    1981 Volume 14 Issue 2 Pages 158-160
    Published: April 20, 1981
    Released: April 03, 2006
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  • DONG IL LEE, SEIICHIRO KAGUEI, NORIAKI WAKAO
    1981 Volume 14 Issue 2 Pages 161-163
    Published: April 20, 1981
    Released: April 03, 2006
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  • NORIAKI WAKAO, KEIKO SUZUKI, MAREHISA ISHIKO
    1981 Volume 14 Issue 2 Pages 164-167
    Published: April 20, 1981
    Released: April 03, 2006
    JOURNALS FREE ACCESS
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