JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 12 , Issue 3
Showing 1-16 articles out of 16 articles from the selected issue
  • YOSHIYUKI TANAKA, MASAHIRO NOGUCHI, HIRONOBU KUBOTA, TADASHI MAKITA
    1979 Volume 12 Issue 3 Pages 171-176
    Published: June 20, 1979
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    The thermal conductivity of gaseous methane and sulfur hexafluoride was measured at temperatures from 25.00°C (298.15 K) to 100.00°C (373.15 K) under pressures up to 90 bar (9 MPa). The measurements were carried out in a vertical coaxial cylinder apparatus on a relative basis. The apparatus was calibrated using Ar, N2, Ne and CO2 as the standard gases. The uncertainty of the thermal conductivity obtained is estimated to be within 2% except in the critical region.
    The thermal conductivity of methane increases steadily with pressure and (∂λ/dT)p is positive throughout the range of experimental conditions. On the other hand, the thermal conductivity isotherms of sulfur hexafluoride intersect each other between 25 and 35 bar. (∂λ/dT)p is positive at low pressures and becomes negative at high pressures. The thermal conductivity of SF6 is found to increase steeply with pressure near the critical point, which may be due to the critical anomaly. The experimental results are analyzed and the thermal conductivities are expressed as functions of temperature and pressure and of density.
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  • TOSHIRO MARUYAMA, KOJI KOJIMA, TOKURO MIZUSHINA
    1979 Volume 12 Issue 3 Pages 177-182
    Published: June 20, 1979
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    An experimental investigation was performed to study the flow structure of slurries of concentrated settling suspensions in horizontal pipes. Visual observation showed that the saltation of solid particles was caused by a transverse vortex which is generated and grows randomly in space and time; and that large-scale motion existed in the whole range of heterogeneously suspended flow.
    To interpret the flow structure, this study utilized the stability concept of stratified flow, presuming that the solid phase behaves like a fluid in the early part of the process. The results showed that the formation of a transverse vortex was predictable from the Kelvin-Helmholtz instability of the stratified flow. The densimetric Froude number based on the depth and net velocity of the water phase classifies three flow regimes: viz., (1) stable, (2) neutral and (3) unstable flows. These correspond to those based on the observed distinct modes of the flow; i.e., (1) sliding on a stationary bed, (2) saltation with a deposit and (3) saltation without a deposit.
    The pressure gradient has no effect on the stability criterion but affects the resulting dynamic process by changing the frequency of generation in the transverse vortex. Measured intensity and the time scale of the wall pressure fluctuations were representative of the vortical motion, which is far larger and stronger than those found in wall turbulence.
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  • SHIGERU MATSUMOTO, AKIHIKO TAKAHASHI, MUTSUMI SUZUKI, SIRO MAEDA
    1979 Volume 12 Issue 3 Pages 183-189
    Published: June 20, 1979
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    Two mathematical models are proposed to represent gas temperature distributions in suspension flows heated at the tube wall. These models are quite different from each other in the turbulent mixing mode of solid particles. Two parameters in these models were determined from experimental measurement of temperature distribution by using a parameter estimation technique. These models express observed temperature distributions well, especially when the loading ratio is smaller than unity. Mean gas eddy diffusivity and Nusselt number were calculated from these two parameters, which could be correlated well with a single nondimensional parameter that represents the operating conditions. By using this correlation and the models, temperature distributions can be easily predicted in the usual practical operating conditions of industrial suspension flows.
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  • HIROYASU OHASHI, TAKUO SUGAWARA, KEN-ICHI KIKUCHI, TOSHIO HENMI
    1979 Volume 12 Issue 3 Pages 190-195
    Published: June 20, 1979
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    Ion exchange resin particles and electrolyte solutions were transported upward through vertical tubes, and mass transfer coefficients between particles and liquid were obtained by measurement of the ion exchange rate under the condition of liquid-side mass transfer control. Tube sizes used were 1.96 and 3.00 cm inner diameter. Particle diameters ranged from 321 to 807 μm, and particle densities were in the range from 1190 to 1390 kg/m3. Other experimental variables were flow rate, species of counter-ion, fractional holdup of particles, and temperature.
    Experimental results were correlated with the following empirical equation under the experimental conditions studied:
    Sh=2+0.44(ε1/3Dp4/3/ν)0.63Sc1/3
    12<(ε1/3Dp4/3/ν)<190, 250<Sc<2300, md<0.014
    where ε, Dp, ν, and md are energy dissipation rate per unit mass of liquid, particle diameter, kinematic viscosity of liquid, and delivered concentration of particles, respectively.
    The above equation is nearly the same as published empirical ones for stirred tanks and bubble columns, which suggests that the effect of turbulent eddies on mass transfer could be identical although the macroscopic flow patterns are apparently different.
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  • KOICHI ASANO, YOSHIMI NAKANO, MASASHI INABA
    1979 Volume 12 Issue 3 Pages 196-202
    Published: June 20, 1979
    Released: April 03, 2006
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    Local measurements of vapor phase heat and mass fluxes and of heat fluxes through condensate liquid film were made for the forced convection film condensation of steam, methanel, benzene and carbon tetrachloride vapors on a small vertical flat plate in the presence of air with air mass fraction of 0.027-0.787.
    Measured vapor phase fluxes are compared with the theoretical value by laminar boundary layer theory over a flat plate with Blasius-type similarity transformation. A new method which enables one to evaluate the surface temperature of the condensate liquid film and the wall heat fluxes in the presence of noncondensable gas is proposed. The effect of vapor shear stress on the rate of heat transfer through condensate liquid film flowing cocurrently with vapor is also discussed.
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  • KAZUO KONDO, KATSUHIDE KITA, ISAO KOIDA, JIN IRIE, FUMIYUKI NAKASHIO
    1979 Volume 12 Issue 3 Pages 203-209
    Published: June 20, 1979
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    A novel technique for separating and concentrating metals with liquid surfactant membranes containing a mobile carrier has recently attracted practical interest through nuclear, hydrometallurgical and waste-water treating processes. In this work, to obtain the basic information for development of a novel separation technique, the extraction of copper was carried out using liquid surfactant membranes containing benzoylacetone as a mobile carrier. The effects of the processes of chelating complex formation and diffusion on extraction rate were examined experimentally and theoretically on the basis of a simple model for facilitated transport. The experimental results could be explained approximately by considering that the overall extraction rates of copper were controlled by the chelating complex formation and diffusion processes in the aqueous phase close to the interface of the liquid membrane.
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  • HIROSHI TAKEUCHI, KATSUROKU TAKAHASHI, KOICHI TOMITA, MAKOTO IMANAKA
    1979 Volume 12 Issue 3 Pages 209-214
    Published: June 20, 1979
    Released: April 03, 2006
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    To investigate the growth rate of a single crystal of sodium chlorate from an aqueous solution, a flow system and an stirred cell were used in the temperature range of 16-30°C. The linear growth rate was first-order with respect to supersaturation, and the surface incorporation coefficient was found to follow the Arrhenius relationship.
    The over-all growth rates of crystals in a cone type fluidized-bed crystallizer were correlated with crystal size. Using the empirical size-dependent growth rate model and the seed size distribution with a sine function, the population balance equation was integrated and the resultant population density was compared with that observed for the time after seeding. As a result, it was found that the predicted size distribution substantiated the behavior of crystals in the fluidized-bed crystallizer.
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  • MASASHI ASAEDA, RYOZO TOEI
    1979 Volume 12 Issue 3 Pages 214-219
    Published: June 20, 1979
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    Flow and diffusional permeabilities of gases in various unconsolidated and consolidated porous bodies were measured in the pressure range of 6-760 mmHg.
    From experimental and theoretical considerations a new method is proposed to obtain the tortuosity factors q or the values of ε/q from flow permeability data. The values are compared with those obtained by the usual diffusion method to obtain good agreement between them.
    A single value of tortuosity factor q (or ε/q) was found to be valid for the whole diffusion region and the viscous flow region for such consolidated or unconsolidated porous body as was used in the study, considered to be relatively homogeneous and monodispersed. Dimensionless flow and diffusional permeabilities are well correlated by the theoretical and empirical equations as a function of the modified Knudsen number.
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  • TADASHI CHIDA, TEIRIKI TADAKI
    1979 Volume 12 Issue 3 Pages 220-224
    Published: June 20, 1979
    Released: April 03, 2006
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    Solid-consuming reactions were analyzed theoretically with a modified structural model in which a pellet consists of a large number of spherical, non-porous particles and the radius of the particle and that of the pellet decrease with time. This model was applied to carbon gasification with carbon dioxide and the leaching of hematite with hydrochloric acid in aqueous solution. The theoretical results are consistent with the experimental ones.
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  • SHOICHI KIMURA, TSUTAO OTAKE, OCTAVE LEVENSPIEL
    1979 Volume 12 Issue 3 Pages 224-229
    Published: June 20, 1979
    Released: April 03, 2006
    JOURNALS FREE ACCESS
    The optimum volume ratio of reactor and regenerator which minimizes the total volume of the two is obtained for solids circulation systems where shrinking core kinetics hold for both gas-solid reaction and regeneration. For the general case the optimum volume ratio for a fixed flow rate of solids is represented graphically in terms of reaction and regeneration conditions. For a special case an approximate analytical solution for the minimization is obtained. The procedure to determine the optimum required volume for the reactor and that for the regenerator is also dealt with.
    The effect of reaction and regeneration conditions and of solids flow rate on the optimum volumes is discussed.
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  • KUNIO ISHIBASHI, AKIHIRO YAMANAKA, NOBUO MITSUISHI
    1979 Volume 12 Issue 3 Pages 230-235
    Published: June 20, 1979
    Released: April 03, 2006
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    Studies on the rate of heat transfer in agitated vessels with special types of impellers were carried out. The impellers used were a double helical ribbon, a quadruple helical ribbon and a helical screw. The liquid media investigated were water, bitumen and aqueous glycerine solutions. Vessel-wall heat transfer coefficients were obtained for each impeller. For the helical screw, an off-centered system was studied and the impeller surface heat transfer coefficients were also obtained. Experimental data were correlated using dimensional analysis.
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  • ABU-BAKR SALEM
    1979 Volume 12 Issue 3 Pages 236-238
    Published: June 20, 1979
    Released: April 03, 2006
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  • MITSUGU IWAOKA, TSUTOMU ISHII
    1979 Volume 12 Issue 3 Pages 239-242
    Published: June 20, 1979
    Released: April 03, 2006
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  • JAGDISH CHAND, DHARAM VIR
    1979 Volume 12 Issue 3 Pages 242-247
    Published: June 20, 1979
    Released: April 03, 2006
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  • SAKUHEI OHMURA
    1979 Volume 12 Issue 3 Pages 247-249
    Published: June 20, 1979
    Released: April 03, 2006
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  • JUN-ICHIRO TSUBAKI, GENJI JIMBO
    1979 Volume 12 Issue 3 Pages 250-251
    Published: June 20, 1979
    Released: April 03, 2006
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