JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 10 , Issue 6
Showing 1-17 articles out of 17 articles from the selected issue
  • TOSHIRO MARUYAMA, KAZUHIRO FUJII, TOKURO MIZUSHINA
    1977 Volume 10 Issue 6 Pages 421-427
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
    The wall mass transfer in unsteady turbulent pipe flows was studied experimentally. Dynamic responses of mass-transfer coefficient to changes in the wall shear stress were measured by the electrochemical method. The results show that there exists an element of dead time and that the frequency response is universally correlated on the Bode diagram by a dimensionless angular frequency with Schmidt number as a parameter. For an analytical prediction, it is useful to assume pseudo-steady eddy diffusivity which includes an empirical dead time.
    A detailed investigation of the dead time was also made through studies on temporal characteristics of turbulence in both steady and transient flows. As a result, the occurrence of dead time is found to be due to the temporal coherence of the structure of turbulence.
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  • TOKURO MIZUSHINA, FUMIMARU OGINO, TADASHI FUKUDA
    1977 Volume 10 Issue 6 Pages 428-434
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
    The effect of injection on the eddy diffusivity of heat in the turbulent core region and the heat transfer rate in the thermally fully developed region was analyzed using a simple model. The analytical results were tested in experiments on the heat transfer of turbulent flows of water in a circular tube of porous wall through which heated water was injected. Measurements of heat transfer rate and temperature profile were made far downstream from the entrance. The experiments were performed for Reynolds numbers of the main flow ranging from 6, 000 to 34, 000 and for injection rates of m=-0.004 to -0.0004.
    It was found that the measured heat transfer rates and the eddy diffusivities of heat could be correlated well by the expressions obtained from the analysis. The j-factor of heat transfer divided by the dimensionless pressure gradient and the eddy diffusivity of heat normalized by Re(-dp*/dx*) were expressed as the sum of the linear function and the hyperbola of the injection rate parameter, m/(-dp*/dx*). In the range of 0>m/(-dp*/dx*)>-0.08 the Chilton-Colburn analogy was found to hold even in the presence of injection.
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  • V. M. H. GOVINDARAO, H. LEKSHMINARAYANAN
    1977 Volume 10 Issue 6 Pages 435-439
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
    Creeping flow hydrodynamics combined with diffusion boundary layer equation are solved in conjunction with free-surface cell model to obtain a solution of the problem of convective transfer with surface reaction for flow parallel to an array of cylindrical pellets at high Peclet numbers and under fast and intermediate kinetics regimes. Expressions are derived for surface concentration, boundary layer thickness, mass flux and Sherwood number in terms of Damkoehler number, Peclet number and void fraction of the array. The theoretical results are evaluated numerically.
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  • IKUHO YAMADA, TAKAITSU IWATA, YOICHI NISHI, SETSURO HIRAOKA
    1977 Volume 10 Issue 6 Pages 440-445
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
    A concept of hypothetical pinch plate which is distinguished from the real pinch point has been proposed to solve the minimum reflux problem of nonideal multicomponent distillation for the operation type. It is assumed that the hypothetical pinch plate takes at a place between the real pinch point and the feed plate in the section where the nondistributed component exists. Any nondistributed component does not exist in the real pinch point, but an allowable small amount of nondistributed component exists in the hypothetical pinch plate. The composition of distillate and bottoms has been calculated by using the component relative volatility evaluated from the liquid composition of the hypothetical pinch plate or the feed plate. Also the normalized θ''s method has been applied to converge the liquid composition of hypothetical pinch plate and the over-all component material balance.
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  • HIROMITSU SHIBUYA, Yuzo URAGUCHI
    1977 Volume 10 Issue 6 Pages 446-450
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
    A simple step response technique is presented to determine effective diffusivities in adsorbent pellets using non-adsorbing tracers NaCl and KCl. The diffusion cell used consists of a pellet and two stirred vessels of extremely different sizes which are connected to both sides of the pellet.
    An analytical solution is presented for boundary conditions different from those reported previously. The effective diffusivities can be evaluated from an arbitrary datum point of a breakthrough curve which is a function only of diffusion time, provided the volume ratio of pellet to detector chamber is specified.
    Experimental values of effective diffusivities were reasonable in comparison with those reported for these kinds of activated carbon pellets.
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  • KATSUYUKI NAKANO, KOICHIRO KUSUNOKI
    1977 Volume 10 Issue 6 Pages 450-454
    Published: December 20, 1977
    Released: March 30, 2006
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    Catalyst fouling in the consecutive hydrogenation of chlorobenzene over rhodium-alumina catalysts was studied with emphasis on the change in the number of rhodium metal atoms exposed on the catalyst. A continuous flow technique, called an elution method, was applied to this study. The adsorption isotherm of chlorobenzene was utilized to determine the number of metal atoms exposed on a freshly prepared catalyst and a fouled catalyst. The fraction of the metal surface area remaining after fouling was correlated with the total coke amount on the catalyst. The decrease in the fraction of metal surface area is proportional to the total coke amount. A slight deviation from linear correlation was observed in the larger fractions of exposed metal.
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  • KAZUO TAKEUCHI, Yuzo URAGUCHI
    1977 Volume 10 Issue 6 Pages 455-460
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
    The chromatographic moving-bed reactor is a new device which possesses functions of both reactor and adsorptive separator. This paper demonstrates experimentally that reaction and separation occur simultaneously in the device for the oxidation of carbon monoxide over activated alumina with first-order irreversible kinetics.
    The observed concentration profiles of the reactant and the product along the longitudinal direction of the bed are compared with the theoretical curves to show that the proposed model is valid. The effect of non-linearity of adsorption isotherms for the product at high surface concentration is also discussed.
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  • SUSUMU FUKUSHIMA, KATSUHIKO KUSAKA
    1977 Volume 10 Issue 6 Pages 461-467
    Published: December 20, 1977
    Released: March 30, 2006
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    Liquid holdup and interfacial areas were measured in packed columns with cocurrent downward flow. An empirical equation of liquid holdup Φt is presented in terms of Reynolds numbers of gas Reg(=dsGgg) and liquid Rel, surface shape factor of packing φ, void fraction ε and ratio of packing to column diameter dp/T, where the ratio is smaller than 0.13. This equation is different for the dispersed bubble flow and other flow regions.
    The empirical equation of interfacial area ap in the respective flow regions varies as follows:
    apdp/(1-Φl/ε)=ωΦ-mRenlReqg(dp/T)-t
    where ω=7.5×10-5, m=Q.2, n=Q.15, q=2/3, t=2.5 for spray flow; ω=2.2×10-4, m=0.3, n=2/3, q=0.2, t=2.5 for pulse flow; ω=3.9×10-3, m=0.1, n=0.4, q=p. t=2 for trickle flow; ω=2.8×10-7, m=0.9, n=1.8, q=0, t=3.3 for dispersed bubble flow.
    The equation of the boundary in the respective flow regions was found by equating the two of them. The predicted boundaries are in excellent agreement with the literature data given from the analysis of liquid pulse frequencies. The predictions for interfacial areas also agree well with the literature data.
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  • SUSUMU FUKUSHIMA, KATSUHIKO KUSAKA
    1977 Volume 10 Issue 6 Pages 468-474
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
    Liquid-phase volumetric coefficients and Peclet numbers in liquid mixing were measured in packed columns with cocurrent downward flow. The empirical equations of liquid-phase volumetric coefficient are distinctly different in spray, pulse and dispersed bubble flow regions.
    The boundaries for the respective flow regions, obtained by combining two of these equations of volumetric coefficient, are in good agreement with the boundaries which have previously been given from the equations of interfacial area in the same fashion.
    The foam flow region, which gives the maximum value of liquid-phase mass-transfer coefficient, was found at higher gas Reynolds number in comparison with pulse and dispersed bubble flow regions.
    Taking the ratio of packing to column diameter dp/T and surface shape factor of packing Ø into consideration, the empirical equation of mass-transfer coefficient is presented in respective flow regions as
    Sh=k*ldp/DA=5×102φ0.3Re1/3lRe1/5gSc1/2(dp/T)2.2
    This equation is applicable to illustrating the literature data in pulse and dispersed bubble flow regions.
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  • MIKIO KONNO, KUNIO ARAI, SHOZABURO SAITO
    1977 Volume 10 Issue 6 Pages 474-477
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
    The well-known equation for the maximum stable drop size in a mixing vessel, dmax/L∝ (ρcn2rL3/σ)-0.6, is in good accord with the data of various investigators. It has been commonly believed that inertial force is the only external force controlling drop breakup. Although the applicable regime of this equation should be limited to the inertial subrange, the data of drop sizes correlated with the above equation do not always lie in the inertial subrange, and some of the data are in the region near the Kolmogoroff length scale. It should also be noted that viscous force acting on such a small drop cannot be ignored in comparison with inertial force, and that the maximum stable drop size is thus controlled not only by Weber number but also by Reynolds number. By introducing the Reynolds number for the drop breakup mechanism, it is explained that small drops are successfully correlated by the above equation.
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  • KATSUJI NODA, KIYOHARU ISHIDA
    1977 Volume 10 Issue 6 Pages 478-480
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
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  • BHUSHAN KUMAR, K. S. N. RAJU
    1977 Volume 10 Issue 6 Pages 480-482
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
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  • HIROKATSU MASUOKA, CHIAKI YOKOYAMA, YASUHIKO ARAI, SHOZABURO SAITO
    1977 Volume 10 Issue 6 Pages 482-484
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
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  • HARUO HIKITA, HARUO ISHIKAWA
    1977 Volume 10 Issue 6 Pages 485-487
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
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  • EIZO SADA, HIDEHIRO KUMAZAWA, M. A. BUTT, J. E. LOZANO
    1977 Volume 10 Issue 6 Pages 487-490
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
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  • KOUICHI MIURA, KENJI HASHIMOTO
    1977 Volume 10 Issue 6 Pages 490-493
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
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  • HIROYASU SEKO, SETSUJI TONE, TSUTAO OTAKE
    1977 Volume 10 Issue 6 Pages 493-495
    Published: December 20, 1977
    Released: March 30, 2006
    JOURNALS FREE ACCESS
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