KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 1 , Issue 2
Showing 1-20 articles out of 20 articles from the selected issue
  • Shiro Ito, Kohei Ogawa, Chiaki Kuroda
    1975 Volume 1 Issue 2 Pages 121-124
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The three-dimensional velocity fluctuations of swirling incompressible flow in a smooth circular pipe are measured by the electrochemical technique and turbulent statistical quantities are studied.
    It is proved that some turbulent statistical quantities (turbulent intensity and one-point double correlation) change by two different flow zones, that is, the forced vortex zone and the quasi-free vortex zone, which are distinguished by the time-averaged velocity distribution.
    The diffusion of dye which is injected into the forced vortex zone is also discussed.
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  • Hajime Unno, Ichiro Inoue
    1975 Volume 1 Issue 2 Pages 125-130
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Mixing parameters representing liquid mixing on a perforated tray are discussed experimentally relating to operational conditions and some tray dimensions. The results are as follows :
    The fluctuating velocity of liquid measured from impulse response consists of two parts. The one is the fluctuating velocity caused mainly by gas flow. The other is the apparent velocity observed in the presence of liquid velocity distribution.
    The Lagrangian time scale may be discussed in connection with the behavior of a liquid element and is found to be correlated with one parameter, namely the fluctuating velocity divided by the square of mean liquid velocity.
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  • Shiro Ito, Toshio Kajiuchi
    1975 Volume 1 Issue 2 Pages 131-136
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The residence time and the kneading in melt extrusion of viscous fluids, Newtonian fluids and power-law model fluids were studied by numerical analysis.
    A single-screw extruder with constant screw pitch and depth was tested.
    Firstly, the velocity and the dissipation energy distributions were obtained from the numerical solution of the equation of motion by an electronic computer.
    Secondly, the residence time distributions was obtained based on a given velocity distribution.
    The kneading is discussed on the basis of input power to the fluid particles.
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  • Masayuki Kasajima, Yoshiro Mori, Akira Suganuma
    1975 Volume 1 Issue 2 Pages 137-142
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The results of experimental study on flow properties of high polymer melts and blended high polymer melts are as follows : (1) the flow characteristics of high polymer component melts and blended high polymer melts can be expressed by the following constitutive equations in which a flow index is a function of shear rate :
    τ=τ° (γ/γ°) m (γ, γ°)
    η=η° (γ/γ°) m (γ, γ°) -1
    where τ is shear stress, γ is shear rate, m is flow index, ηis viscosity, and superscript ° means a value in an arbitrarily chosen standard state. Then, (2) the above flow index m is expressed as
    m (γ, γ°) =α/2-log (γγ°) +β
    where α and β are constants for flow properties. Using the above equations, the flow characteristics of high polymer melts and blended high polymer melts in high shear rate region can be estimated with the characteristics obtained experimentally for low shear rate. In this series of experiments the applicable region is 0<m≤1.
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  • Ryohei Yamazaki, Tetsuo Okita, Genji Jimbo
    1975 Volume 1 Issue 2 Pages 143-148
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    This paper is concerned with the behavior of slugs and pressure pulsation in slugging beds.
    A slugging state, which is composed of a pair of slugs, namely a stationary slug and a dynamic slug, and hence is different from that defined by Stewart and Davidson, was newly found and the following results were obtained.
    (1) The frequency of slug formation can be determined by the rising velocity of a dynamic slug, the height of formation of a stationary slug and the height of a fixed bed.
    (2) The periodical motion of these slugs can be explained by assuming that there is a part of non-fluidized state just under the rising dynamic slug.
    A theoretical equation for predicting pressure fluctuation at the bottom of the bed was derived, based on these results and confirmed by experiment.
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  • Kunihiko Takeda, Hirotsugu Hattori
    1975 Volume 1 Issue 2 Pages 149-154
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    So as to prevent the gas flow from leaving the apparatus without permeating the annular dense bed, the upper part of the vessel was closed and holes with screen were arranged as the gas outlet, side by side, surrounding the annular dense bed in the side wall.
    Hydrodynamic examination showed that the effectiveness of gas-solid contact is much improved.
    In addition to the above-mentioned improvement, an inner cylinder was mounted vertically in the center of the vessel for the purpose of increasing the stability of the spout.
    The range of conditions for stable spouting was remarkably extended by the effect of the inner cylinder.
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  • Tohru Sakai, Makoto Seo, Nobuichi Ohi
    1975 Volume 1 Issue 2 Pages 155-159
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The resistance to mass transfer and the effect of mass transfer on selectivity in a catalytic gas-liquid reaction were evaluated for the simultaneous hydrogenation of allyl alcohol with a suspended Pd/C catalyst in a stirred vessel at atmospheric pressure.
    In this system, the total resistance consists of three resistances in series, i. e., those to transfer hydrogen through the liquid surrounding bubble and solid (1/kLab, 1/ksas) and the one offered to the chemical reaction taking place on the surface of catalyst.
    To separate 1/ ksas from the chemical resistance at surface of catalyst for transition region where both resistances are comparable in magnitude, hydrogen concentration at catalyst surface (CHs) was related to that at gas-liquid interface (CH*) with the ratio of overall rate to chemical reaction rate. Thus 1/ ksas can be evaluated individually using the values of CHs, CH*, 1/ kLab and chemical reaction rate previously determined.
    The correlation between 1/kLab or 1/ ksas and operating variables such as gas flow rate and rate of stirring were examined.
    Selectivities determined under various operating conditions were in good agreement with calculated values.
    When mass transfer is rate-controlling, estimation of the selectivity in connection with the operating variables was proposed using the kinetics of the chemical reaction taking place on catalyst surface.
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  • Takuo Sugawara, Hiroyasu Ohashi, Teiriki Tadaki
    1975 Volume 1 Issue 2 Pages 160-165
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The reaction characteristics of the vapor-phase photochlorination of chloroform were studied in an annular reactor under laminar flow conditions.
    The theoretical analysis of the effect of the distributions of light intensity, the profiles of fluid velocity and diffusion rates on the extent of conversion shows the possibility of an analysis similar to that for the usual thermochemical plug-flow reactor.
    The estimation of incident intensity is the only additional parameter for analyzing the reaction characteristics at the higher degree of conversion.
    Theoretical conversions by the radial light model were computed with the filter effect of cooling water. They agreed well with experimental results obtained for various chlorine and chloroform concentrations and temperature levels.
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  • Kiichi Teruya, Syuji Hosako, Issei Nakamori
    1975 Volume 1 Issue 2 Pages 166-168
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    To obtain the fundamental data for the extraction process of separating any metal ion as the metal-bromo complex from the various metal ions in hydrobromic acid solutions, we found the solubility and tie-line data of the system of hydrogen bromide-water-methyl isobutyl ketone at 25°C.
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  • Kiichi Teruya, Syuji Hosako, Issei Nakamori
    1975 Volume 1 Issue 2 Pages 169-171
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    To obtain the fundamental data for the extraction processes of separating any metal ion as the metal-bromo complex from the various metal ions in hydrobromic acid solutions, we studied the distribution equilibria of hydrogen bromide between water and methyl isobutyl ketone at 25 °C, and obtained the distribution constant KD= 5.26×10-8 and the ion-pair formation constant in the methyl isobutyl ketone phase KA=1.24×104l/mol.
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  • Minoru Yasuda, Hiroyuki Kawade, Takashi Katayama
    1975 Volume 1 Issue 2 Pages 172-175
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Vapor-liquid and liquid-liquid equilibrium data at 25°C are presented for ternary and constituent binary systems containing methanol, cyclohexane and carbon tetrachloride, in which a two-liquid region exists between methanol and cyclohexane.
    Equilibrium data of both kinds at 25°C are also obtained for the two binary systems methanol-iso-octane and methanol-n-heptane, which have a miscibility gap in each liquid phase.
    These vapor-liquid equilibrium data were obtained by static equilibration in the presence of diluent nitrogen by chromatographic analysis of the saturated vapor.
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  • Hironobu Kubota, Yoshiyuki Tanaka, Tadashi Makita
    1975 Volume 1 Issue 2 Pages 176-179
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The P-V-T relations of liquid n-butyl alcohol are presented along five isotherms : 25.0, 30.0, 40.0, 50.0 and 60.0°C. The pressure ranged from atmospheric to 1, 500 bars. The experimental results are estimated to be accurate within 0.3%.
    All the data obtained are found to fit the Hudleston equation, relating pressure and volume at constant temperature.
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  • Takao Kokugan, Masaru Shimizu, Shigefumi Fujita
    1975 Volume 1 Issue 2 Pages 180-185
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    By using He-Ar gas mixture, the separation efficiency (η) of a thermal diffusion column was measured over a wide range of operating conditions. It was found that at large separation (dimensionless feed flow rate R=σF/Gnat≤0.2) the separation efficiency curve (β vs.η, β : cut) was independent of feed position (ζ0=LS/LT) and the maximum lay on PQ-line (P : β=CF, η=1;Q : β=0.5, η=0), but at small separation (0.2≤R≤ 0.4) the β that gave the maximum separation efficiency (ηmax), that is to say, βmax, was shifted from 0 to 1, as ζ0 was changed from 0 to 1, but the value of ηmax remained nearly constant. At still smaller separation (0.4 ≤ R< 0.6) the curve was gradually flattened.
    By using the dimensionless feed flow rate R, all experimental data can be summarized on a single curve for different temperatures and feed gas concentrations. It was also found that the maximum separation efficiency decreases exponentially as feed flow rate increases, and is proportional to both the two-thirds power of temperature ratio (ΔT/T) and to the square root of feed gas concentration product CF (1-CF).
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  • Yuji Naka, Kikuo Kobayashi, Takeichiro Takamatsu
    1975 Volume 1 Issue 2 Pages 186-190
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Ridge and valley are defined as the curves by which the directions of the tie lines describing vapor-liquid equilibrium relationship are divided into two regions, and these curves act as the limitation lines on the composition profile of a distillation column. To design and to control azeotropic distillation columns, therefore, it is necessary that ridge and valley be easily calculable.
    This paper shows that the composition profile in a distillation column for the total reflux can exist on ridge or valley, and that these lines can be calculated approximately by using the above characteristics. This can be done by an iterative calculation of dew point or bubble point starting from the neighborhood of the azeotrope or pure component. Some numerical examples show very good results.
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  • Tadashi Shirotsuka, Yoshinori Kawase
    1975 Volume 1 Issue 2 Pages 191-196
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Measurements are made of the effect of frequency of formation on the velocity of drops rising in a chain through quiescent liquids. The terminal velocity of drops of a given size rising in a quiescent liquid increases as the frequency with which they are formed at a nozzle increases. The variation of velocity of the drop with frequency of formation is considerably influenced by the eccentricity and the wake of drops.
    Theoretical analyses are performed for motion and mass transfer of drops rising in a chain at high Reynolds number. The present analysis evaluates the minimum effect of frequency of formation on the velocity of drops and shows a trend similar to that of the experimental data.
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  • Yoshiro Mori, Akira Suganuma
    1975 Volume 1 Issue 2 Pages 197-201
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Under an assumption that particle size x follows log-normal distribution in its parent population, any population mean particle size defined by
    Γ= {∫0xa+bƒ(x)dx/∫0xbdx} 1/cor Γ=exp {∫0 (lnxe)ƒ(x)dx}
    can be estimated by the following Hatch-Choate formula.
    gH=exp (Aμ+2)
    μ=ni=1yi/n, ô2ni=1 (yi-μ) 2/ (n-1)
    yi=lnxi
    (A, B) = {a/c, a2+2ab/2c} or {e, 0}
    This estimate gH, which may be called sample mean particle size by Hatch-Choate, follows asymptotically log-normal distribution, that is, h=ln gH follows asymptotically normal distribution N {Ω, D2 (h)}.
    Ω=lnΓ
    D2 (h) = (A2/n) σ2+ {2B2/ (n-1)} σ4
    So far as sample size n is larger than about 100, the distribution of h= ln gH can be approximately expressed by N {Ω, D2 (h)}. Owing to this conclusion, some of statistical tests and inference about population mean particle sizes become possible with a numerical table of t-distribution.
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  • Sukekuni Mukataka, Jiroh Kobayashi
    1975 Volume 1 Issue 2 Pages 202-206
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Experimental and theoretical studies are carried out for the effect of micromixing on the hydrolysis of sucrose by invertase in a continuous-flow stirred-tank reactor. The rate equation is expressed as a lower order reaction than first with respect to sucrose concentration. In the experiment, the feed liquid was changed from a solution of sucrose to that of a mixture of invertase and sucrose, and the sucrose concentration in transient state was measured.
    Theoretical analysis has been made on the basis of the micromixing model proposed in the previous paper. The values of parameter in the model are determined from correlation with the Re, which has been obtained previously by experiments with second-order reaction.
    From the experimental results, it was found that micromixing promotes hydrolysis. These results are predicted theoretically and the observed data agree well with the theoretical values.
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  • Tetsu Fujii, Osamu Miyatake, Toshiaki Tanaka, Tsutomu Nakaoka, Hirosuk ...
    1975 Volume 1 Issue 2 Pages 207-212
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Since there is little information so far on the phenomena of flash evaporation in a flash chamber of comparatively short length, the authors measured temperature and velocity profiles in a 1.0 meter long flash chamber with and without interstage baffle plates.
    The results obtained above are quite different from those obtained from a chamber of comparatively long length.
    Without baffle plate, flashing occurs at the rear of the chamber, where the submerged hot jet of liquid reaches the liquid-vapor interface, and the reverse flow of liquid exists near the liquid-vapor interface.
    When a baffle plate is installed in the flash chamber, flashing occurs at the front part of the chamber and the reverse flow of liquid exists near the bottom of the chamber.
    In the case of a short flash chamber, evaporation is considerably enhanced by the installation of a baffle plate.
    Also, the authors obtained empirical equations for non-equilibrium temperature difference from the experimental results.
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  • Ken Tsuda, Yoshitada Suezawa
    1975 Volume 1 Issue 2 Pages 213-218
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The effect of corrosion on cavitation erosion was investigated by using the magnetostrictive method in HCl solutions ranging in pH from 0.5 to 4.
    The cavitation damage was very severe under corrosive environment. It is shown that this is principally due to the deterioration of material surface, which becomes very brittle by the action of corrosion.
    The effect of pH of test liquid on weight loss of cavitation erosion was very similar to the behavior of pure corrosion, that is, weight loss increased rapidly at pH=43, and progressively decreased with increasing acidity above pH≈2. This behavior can be explained by the film of corrosion products and the adsorption of Cl-.
    From these results a conventional equation, by which it was possible to estimate the weight loss by cavitation erosion under corrosive environment from that of pure corrosion and erosion, is presented.
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  • Tadashi Shirotsuka, Yoshinori Kawase, Hajime Unno, Ichiro Inoue, Ken T ...
    1975 Volume 1 Issue 2 Pages 219-228
    Published: March 10, 1975
    Released: October 21, 2009
    JOURNALS FREE ACCESS
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