JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 14 , Issue 3
Showing 1-17 articles out of 17 articles from the selected issue
  • NAOHIRO SHIRAGAMI, ICHIRO INOUE
    1981 Volume 14 Issue 3 Pages 173-177
    Published: June 20, 1981
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    Pressure loss for laminar flow in a 90-deg square bend is discussed on the assumption that the friction factor can be expressed as a function of the Dean number. The turbulent viscosity is newly defined so that the product of the friction factor and Reynolds number for turbulent flow has the same value as that for laminar flow in a straight square duct, i.e. 14.2. Using the newly defined turbulent viscosity the friction factor for turbulent flow can be related to Reynolds number Reμ and the dimensionless curvature a/R.
    Then the empirical formulae of the friction factor for both laminar and turbulent flows in a 90-deg square bend is obtained by experiments for the dimensionless curvatures 0.0365, 0.0729, 0.146 and 0.292, and Reynolds numbers range from 4.8 × 102 to 2.4 × 104. The difference between the pressure at the outer wall and that at the inner wall in the 45-deg cross-section of a bend can be related to the dimensionless curvature for Reynolds number such as Reμ>5000.
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  • TORU TAKAMATSU, YOSHIKI HASHIMOTO, MANABU YAMAGUCHI, TAKASHI KATAYAMA
    1981 Volume 14 Issue 3 Pages 178-182
    Published: June 20, 1981
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    The formation of single charged drops in a uniform electric field is studied as a fundamental of "electrostatic liquid extraction". Theoretical equations are derived for the volume and the electric charge of the drop formed at the tip of an electrified nozzle that protrudes from one of a pair of parallel plate electrodes. The experimental measurements were performed in atmosphere by use of three nozzles (0.1, 0.15 and 0.26 cm O.D.) in an electric field range of 0-6 × 105 V•m-1.
    It has been clarified theoretically and experimentally that drop volume decreases remarkably with increase of electric field strength and also with increase of protrusion length (0-1.0 cm) of the nozzle. The theoretical equation gives a somewhat larger drop volume than that obtained experimentally, but it represents well the effect of protrusion length on volume. Experimental data of drop charge are in good agreement with the theoretical predictions when the nozzle protrusion length is relatively short.
    Although some deviations are found between the experimental and the theoretical values, the behavior of single charged drop formation is predicted by the theoretical equations presented.
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  • MORIO OKAZAKI, TAKESHI YAMASAKI, SHOICHIRO GOTOH, RYOZO TOEI
    1981 Volume 14 Issue 3 Pages 183-189
    Published: June 20, 1981
    Released: April 03, 2006
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    The effective thermal conductivity was investigated for granular beds of various binary mixtures. Samples used were two or three sizes of glass beads, resin particles and copper spheres respectively. A unit cell model was developed after due consideration of particle diameter ratio and it was assumed that the coordination number was a function of diameter ratio and volume fraction of components. Predicted values coincided with experimental ones, in which the ratio of diameters was 1-2.8 and the ratio of solid conductivities was 1-5.8, within 6% deviation.
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  • SHOICHI KIMURA, JUN-ICHI NAKAGAWA, SETSUJI TONE, TSUTAO OTAKE
    1981 Volume 14 Issue 3 Pages 190-195
    Published: June 20, 1981
    Released: April 03, 2006
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    The volume reaction model based on a second-order rate equation with a first-order dependence on each solid and gaseous reactant concentration was solved to predict the detailed performance of gas-solid reactions. The model was discussed in relation to the shrinking core model and the homogeneous reaction model and also compared with the volume reaction model based on the first-order rate expression.
    The predicted results are verified in the oxidation of iron sulfide particles to describe the general behavior in the wide region extending from chemical reaction control to diffusion control.
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  • YASUHIRO MURAKAMI, MASAHARU TAKAO, OSAMU NOMOTO, KAZUHIRO NAKAYAMA
    1981 Volume 14 Issue 3 Pages 196-200
    Published: June 20, 1981
    Released: April 03, 2006
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    To represent the macro-mixing rate process in a batch reactor, a combined model of the extremes for mixing is proposed by extending the treatment of Miyawaki''s model. This model is characterized by the segregation function and has the simplest mixing structure: that composed of both complete segregation and perfect mixing. By equating the intensity of segregation derived for the proposed model to that for the batch mass exchange-type model, the model parameter can be related as a function of macro-mixing time with the mixing parameter of the mass exchangetype model. This treatment of the model is experimentally confirmed by using three kinds of reactions having different rate constants. The mixing parameter of this model calculated from the experimental data of irreversible second-order reactions with different rate constants in a wide range of operational conditions is more successfully correlated to the Reynolds number of the reaction system. Further, the overall reaction performance is found to be characterized by a dimensionless number which is given from both the reaction rate and the mixing parameter.
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  • TAMOTSU HANZAWA, KUNIO KATO, TEIRIKI TADAKI
    1981 Volume 14 Issue 3 Pages 201-207
    Published: June 20, 1981
    Released: April 03, 2006
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    The temperature distributions and concentration distributions of reactant gas in a horizontal epitaxial reactor were investigated experimentally and theoretically in the high flow rate range, that is, Q= 10-60 l/min (20°C, 1 atm, Re=160-1400). The temperature and concentration distributions in the reactor in the case of no axial temperature gradient in the high flow rate range were between the calculated distributions for spiral flow and the calculated distributions for axial flow with no cross-sectional flow. When the flow rate is less than 20 l/min, the temperature and concentration distributions are approximately calculated by the fundamental equations in the case of stable spiral flow. However, when the flow rate is larger than 50 l/min, these distributions are approximately calculated by the fundamental equations in the case of axial flow with no cross-sectional flow. An empirical equation for the estimation of gas temperature distributions in the high flow rate range was obtained.
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  • KATSUKI KUSAKABE, SHIGEHARU MOROOKA, YASUO KATO
    1981 Volume 14 Issue 3 Pages 208-214
    Published: June 20, 1981
    Released: April 03, 2006
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    Copper deposition from acidic aqueous solutions containing copper ion was studied in rectangular fluidized bed electrodes for liquid-solid and gas-liquid-solid systems. The effective specific resistance of particle phase, ρm, was determined by comparison of the experimental potential profile with the theoretical one.
    The value of ρm decreased with increase in gas velocity, and the gas flow increased the total cell current by 10-30% at a given cell voltage in the range of 15 to 30% bed expansion. No explicit effects of fluidized bed height and particle diameter on ρm were observed.
    The overall effective specific resistance of bed, ρb, was measured with an alternating current bridge circuit, and the relationship between ρm and ρb is discussed. The charge transfer in the particle phase was analysed by the parallel effective resistance model based on the charge conductive mechanism and the collision mechanism.
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  • YASUO KOUSAKA, KIKUO OKUYAMA, YOSHIYUKI ENDO, HIROSHI TANAKA
    1981 Volume 14 Issue 3 Pages 214-218
    Published: June 20, 1981
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    Three basically different principles for density measurement of aerosol particles, based on 1) separate measurements of mass concentration and size distribution, 2) simultaneous measurements of gravitational settling velocity and electrical mobility and 3) balance of gravitational and Coulomb''s force, have been tested. Modifications by combining classification of particles by electric differential mobility analyser to each of the above three methods have also been tested. The easiest and most accurate method has been found to be that based on 3) above, which is similar to Millikan''s experiment for the evaluation of elementary charge, when particles are larger than 0.5 μm. For smaller particles the method based on 1) above is applicable, but there is a problem in accuracy and there is a disadvantage in that the method requires stability in aerosol concentration and size during density measurement.
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  • MASABUMI NISHIKAWA, MASAO NAKAMURA, HIDEHARU YAGI, KENJI HASHIMOTO
    1981 Volume 14 Issue 3 Pages 219-226
    Published: June 20, 1981
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    Based on the finding that the bubbling-controlling condition, the agitation-controlling condition, or the intermediate condition may predominate in an aerated mixing vessel, correlative equations for kLa valid for a wide range of operating conditions are proposed. In addition, the type of mixing of the gas phase in aerated mixing vessels is discussed, and plug-flow type mixing is recommended since the logarithmic mean value of entrance and outlet compositions of gas gives a reasonable gas absorption rate.
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  • MASABUMI NISHIKAWA, MASAO NAKAMURA, KENJI HASHIMOTO
    1981 Volume 14 Issue 3 Pages 227-232
    Published: June 20, 1981
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    Aerated mixing vessels are often used in chemical and biological industries. When the rate of gas absorption controls the rate of reactions, kLa is used as the design standard.
    It was previously reported by the present authors that the overall vessel condition varied from bubbling-controlling condition at relatively high gas rates to agitation-controlling condition at relatively high impeller speeds via intermediate condition. According to this two-region model, kLa for the airwater system in the aerated mixing vessel has been correlated well in a wide range of operational conditions.
    In this report, the two-region model is applied to Newtonian liquids with various physical properties and to non-Newtonian liquids, and reasonable dimensionless correlative equations are obtained.
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  • MASAAKI MURAKI, TOYOHIKO HAYAKAWA
    1981 Volume 14 Issue 3 Pages 233-238
    Published: June 20, 1981
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    Introduction of energy integration into the distillation separation process is very important from the viewpoint of energy saving and cost reduction, but it is difficult to solve these synthesis problems because there exists information feedback between the distillation separation sequence and the heat exchanger network.
    A useful method composed of thre ephases - decomposition, optimization and selection - is proposed for solving these synthesis problems. The list of distillation separation sequences is effectively used to generate directly only feasible subproblems in the decomposition phase, and to select the optimal distillation separation process among many candidates in the selection phase. In the optimization phase the constrained Simplex method is doubly used to search the optimal solution of the subproblem, in which energy match is considered. A synthesis problem of a 5-component distillation separation process with energy integration demonstrates the effectiveness of this synthesis method.
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  • RICARDO ALVAREZ, JULIO L. BUENO, JOSÉ COCA
    1981 Volume 14 Issue 3 Pages 239-241
    Published: June 20, 1981
    Released: April 03, 2006
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  • FUKUJI YAMASHITA, AKIHIRO IGUCHI, SIGEFUMI FUJITA, HIDEO YOSHII
    1981 Volume 14 Issue 3 Pages 241-243
    Published: June 20, 1981
    Released: April 03, 2006
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  • YOSHIHIRO KAWAGUCHI, HITOSHI KANAI, HIROYUKI KAJIWARA, YASUHIKO ARAI
    1981 Volume 14 Issue 3 Pages 243-246
    Published: June 20, 1981
    Released: April 03, 2006
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  • JUN-ICHI KAWABATA, YONESHIRO TAZAKI, TADATOSHI CHIBA, KUNIO YOSHIDA
    1981 Volume 14 Issue 3 Pages 246-249
    Published: June 20, 1981
    Released: April 03, 2006
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  • KOHEI OGAWA
    1981 Volume 14 Issue 3 Pages 250-252
    Published: June 20, 1981
    Released: April 03, 2006
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  • YOSHIHIRO IIDA, SHIGERU OSHIMA
    1981 Volume 14 Issue 3 Pages 253-254
    Published: June 20, 1981
    Released: April 03, 2006
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