JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 11 , Issue 2
Showing 1-17 articles out of 17 articles from the selected issue
  • SHIGERU MORI, TOSHIAKI INOUE, AKIRA TANIMOTO
    1978 Volume 11 Issue 2 Pages 83-88
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
    Heat transfer to a fully developed laminar flow in a parallel-plate wall reactor, which is a variation of the so-called tube-wall reactor, was analyzed theoretically. The heat conduction in the reactor wall is accounted for, and it is assumed that an interfacial reaction simply causes uniform heat generation or such heat generation as decreases linearly along the flow.
    The influence of the interfacial heat generation on the interfacial temperature was found to be significant, and the influence of the conductance ratio of wall to fluid Rw thereon was found to be more significant than for the case without heat generation. With respect to the local Nusselt number, when the heat generation varies along the direction of flow, the influence of the heat generation is significant and the influence of Rw tends to be increased.
    In addition to the above, experiments were carried out in which heat was generated electrically at the interface. The experimental results agreed fairly well with the theoretical predictions.
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  • SHIGERU MATSUMOTO, SATOSHI OHNISHI, SIRO MAEDA
    1978 Volume 11 Issue 2 Pages 89-95
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
    Heat transfer and flow characteristics of gas-solid suspension flows in a vertical 26 mm I.D. tube were investigated using spherical glass and copper beads. Particle size ranged from 72 to 1130 microns; Reynolds number 12, 000 to 24, 000; and loading ratios of solids up to 10. The results indicated a slight increase in the wall-heat transfer coefficient for the glass beads at the higher loading ratios, and essentially no increase for the 321-micron copper beads for the range of variables covered. A new general correlation of wall-heat transfer coefficients to gas-solid suspensions is presented for uniform wall temperature conditions.
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  • HARUO HIKITA, KOSAKU ISHIMI, YASUO OMOTEHARA, TOSHIO FUKASE
    1978 Volume 11 Issue 2 Pages 96-101
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
    The effects of gas and liquid flow rates on gas-phase mass transfer from a turbulent gas stream into a laminar falling liquid film in wetted-wall columns with cocurrent and countercurrent gasliquid flow were studied. Numerical solutions were obtained for the average gas-phase Sherwood number as functions of the gas-phase Reynolds number based on the gas velocity relative to the liquid surface, the dimensionless interfacial gas velocity, the gas-phase Schmidt number and the dimensionless column height. Experiments were carried out on the absorption of ammonia into aqueous sulfuric acid solution, using two columns of different dimensions. The agreement between experimental and predicted effects of both gas and liquid flow rates on gas-phase mass transfer rate was found to be fairly good.
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  • YASUO HIROSE, MITSUTOSHI TSUDA
    1978 Volume 11 Issue 2 Pages 102-106
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
    For solving a set of simultaneous non-linear algebraic equations the Newton-Raphson method is a powerful mathematical tool. If the number of unknown variables is not large and an appropriate initial set of variables is used, no problem occurs. But if the number of variables is extremely large, overcorrection often takes place in the course of calculation and the calculation fails to converge. To adjust these overcorrections, several techniques have been proposed.
    In distillation problems, the number of unknown variables is generally very large. For this reason we have frequently met problems which never converge even if the above-cited techniques are applied. To solve such difficult problems, two techniques are newly presented in this report. The first is a straightforward determination of an optimum attenuation factor to reduce the scalar value of corrections. The second is a mapping technique, by which physically nonadmissible values can be converted into admissible ones. Solving numerical examples of distillation problems, it was shown that simultaneous usage of the techniques presented is useful for the Newton-Raphson method.
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  • KATSUHIKO FUJIKAWA, MITSUNORI HOZAWA, NOBUYUKI IMAISHI
    1978 Volume 11 Issue 2 Pages 107-111
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
    Effects of desorption and absorption of surface tension-lowering solutes through a turbulent gas-liquid interface on liquid-phase mass transfer coefficients were studied experimentally by the use of oxygen as a tracer component.
    A stirred contactor was used in the experimental work. Water and nitrogen were used as the liquid and gas phases, and acetone and methanol were chosen as the solutes.
    The results revealed that the coefficients increased with an increase in desorption rate, and that they decreased with an increase in absorption rate. The difference between the desorption and the absorption lies in the fact that the surface tension-driven force induced by the transfer of the solutes promotes the original turbulence near the interface in desorption, while it inhibits turbulence in absorption.
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  • L. T. FAN, KEI MIYANAMI, LIANG-SHIH FAN
    1978 Volume 11 Issue 2 Pages 112-119
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
    A reaction model of extractive coal liquefaction in which the coal particle maintains its integrity throughout the reaction is presented. The effects of solvent diffusion, liquid product diffusion, and chemical reaction are taken into consideration in the model. Experimental data based on the NenKen extractive coal liquefaction process have been employed to test the validity of the model. Fractional extraction and concentration profiles of the hydrogen donor solvent, convertible solid and liquid product in the coal particle have been numerically simulated based on the model, and the results are graphically presented.
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  • YOSHIO HARANO, KOICHI OOTA
    1978 Volume 11 Issue 2 Pages 119-124
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
    Heat evolution rate curves were recorded with KBrO3-quiet supersaturated aqueous solution at constant cooling temperature, T, by using a differential scanning calorimeter and were analyzed on the basis of the growth rate of all crystallites pre-formed in the sample solution. Taking microscopic observation into account, the expression of the overall growth rate, R, was derived, on the assumption that the crystallite surface is Kossel''s and that its growth rate is determined by two-dimensional nucleation rate, J''=k1''Sm''.
    R=βhAJ''≈k1"(C0-C)2/3Sm'' (1)
    where C, C0 and S are concentration at t=t and =0 and supersaturation ratio, respectively. m'' is number of solute in a critical nucleus and is not constant, but depends on S and T.
    The values of two-dimensional nucleation parameters (m'' radius, free edge energy σ'' and surface energy estimated from σ'' and activation energy) were of reasonable order of magnitude. Comparison of these values with those of the three-dimensional parameters obtained previously is discussed. It may be concluded that Eq. (1) and hence the expression for J'' proposed in this paper are adequate for the growth rate and two-dimensional nucleation rate, respectively.
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  • HIROTSUGU HATTORI, KUNIHIKO TAKEDA
    1978 Volume 11 Issue 2 Pages 125-129
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
    In the commonly used top-outlet spouted bed, the solid particles are restricted in size to relatively coarse ones. As suggested by Mathur and Lim, the use of coarse particles would not be advantageous for carrying out heterogeneous gas-phase reactions.
    This paper describes an attempt to reduce the particle size for the side-outlet spouted bed which was previously proposed. Particles as small as those used in the fluidized bed may also be used in the side-outlet spouted bed with inner draft-tube.
    The gas conversions have been calculated, based on the observed gas flow pattern in the annulus, for the cases of both independent and dependent of reaction rate on particle size. From the results of the calculated gas conversions, it was found that the side-outlet spouted bed with inner draft-tube gave higher gas conversions than any other spouted beds.
    The structure of the gas outlet has been reformed so as to be suitable for the use of small-sized particles. Instead of putting screens on the gas outlet openings, a stationary solid bed has been attached outside the openings surrounding the annnulus.
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  • HIROYASU SEKO, SETSUJI TONE, TSUTAO OTAKE
    1978 Volume 11 Issue 2 Pages 130-135
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
    The cracking of methylcyclohexane (MCH) over silica-alumina catalyst and the regeneration of catalyst deactivated due to coking are applied to a fluid catalytic cracker system consisting of a cracker and a regenerator, and a system model is derived from the coke and heat balances. From numerical computations of this model, it is found that the system, although unstable, can be kept near the steady state point using both the feed temperature of MCH and the air flow rate in the regenerator as control variables. A control design to keep the conversion of MCH at a constant value is developed by means of a minimum time control theory. Further, effects of operating and reaction conditions on system stability are discussed.
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  • KOICHI IINOYA, KAZUTAKA MAKING, NORIAKI IZUMI, YASUSHIGE MORI
    1978 Volume 11 Issue 2 Pages 136-142
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
    The design of fabric filter systems has up to now not been based on engineering analysis but rather on empirical practice. A procedure for determining the optimal design of these systems is developed by formulating an economic evaluation function based on the cleaning cycle for both timer and pressure-switch type filter systems.
    The annual cost is formulated in terms of the fixed and operating costs of a fan, the fixed cost of a filter and the fabric replacement cost. It is assumed that the fabric life is constant or is equal to the allowable repetitions of cleaning cycles, so that the economically optimal operating conditions can be calculated using the above-mentioned formula to minimize the annual cost.
    The optimal number of compartments depends on the inlet dust concentration. For a system in which fabric life is limited by repetition of the cleaning cycles, the optimal operating conditions depend on dust concentration and the number of compartments. However, for a filter system with constant fabric life, the concentration may not affect the optimal conditions.
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  • SHIGEO KATOH, TOSHIHIRO YANAGIDA, Eizo SADA
    1978 Volume 11 Issue 2 Pages 143-146
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
    For hydrolysis of amylose by β-amylase the effects of liquid flow rate, ultrafiltration flux and tube radius on the performance of a membrane reactor of two coaxial tubes were studied. The efficiency of separation of the product from the reacting stream in this reactor was improved by use of a small radius tube and by operation at a high ultrafiltration flux. The calculated results of the product concentration showed general agreement with the experimental results obtained with the membrane reactor.
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  • S. C. JAIN, K. S. N. RAJU
    1978 Volume 11 Issue 2 Pages 147-149
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
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  • YASUO HIROSE, YOSHINORI KAWASE, MITSUO KUDOH
    1978 Volume 11 Issue 2 Pages 150-152
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
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  • KAZUYUKI CHIHARA, MOTOYUKI SUZUKI, KUNITARO KAWAZOE
    1978 Volume 11 Issue 2 Pages 153-155
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
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  • TAKESHI KATAOKA, HIROYUKI YOSHIDA, SHIGERU IKEDA
    1978 Volume 11 Issue 2 Pages 156-158
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
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  • YOSHIO HARANO, KOICHI OOTA
    1978 Volume 11 Issue 2 Pages 159-161
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
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  • HIDEO KAMEYAMA, SIGETAKA FUJII, TOHRU KAWAHARA, KUNIO YOSHIDA
    1978 Volume 11 Issue 2 Pages 161-162
    Published: April 20, 1978
    Released: March 31, 2006
    JOURNALS FREE ACCESS
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