KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 5 , Issue 1
Showing 1-17 articles out of 17 articles from the selected issue
  • Johtaro Itoh, Kazuo Niida, Katsuo Shiroko, Tomio Umeda
    1979 Volume 5 Issue 1 Pages 1-6
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A method based on available energy concept of thermodynamics is presented for the analysis of heat availability in a distillation system which consists of a column-internal and heat-exchange subsystems. A heat availability diagram is constructed by plotting Carnot efficiency against heat load, and used to learn the effect of energy variables change on the available energy. As a result, the effects of operating variables on the loss of available energy are made clear. To demonstrate the applicability of the present method, heat availability of typical distillation systems with integration is analyzed.
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  • Kazufumi Yamada, Tadashi Chida, Shinji Takahashi, Teiriki Tadaki
    1979 Volume 5 Issue 1 Pages 7-11
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Theoretical and experimental study was carried out on the characteristics of mass transfer through a free surface of stirred liquid. Carbon dioxide was absorbed into toluene through the free surface of stirred liquid in an absorption cell equipped with baffles and a paddle agitator.
    For the analysis of the experimental data, the surface renewal model was modified by extending it to unsteady state and by ignoring the effect of the thickness of surface element. It was found that the experimental results were explained well by the proposed model and that the rate of surface renewal increased remarkably with the rate of revolution of the agitator.
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  • Mitsuharu Ide, Jiro Mada, Hisashi Shinohara
    1979 Volume 5 Issue 1 Pages 12-18
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The shape, break up length and operating region of a liquid jet containing small solute bubbles were investigated experimentally by a photographic technique. The following results were obtained.
    1) The diameter Dl and surface area S of the liquid jet containing small solute bubbles were correlated by the following equations :
    Dl/D= (1+2gl/u22) -1/4
    S/S0= (2u22/3gl) {(1+2gl/u22) 3/4-1}
    where D is inside diameter of nozzle, g is acceleration of gravity, l is liquid jet length, u2 is mean linear velocity of gas-liquid mixed fluid at nozzle exit and S0Dl.
    2) The liquid jet containing small solute bubbles has only a region of turbulent liquid jet. A dimensionless break up length (l/D) is expressed by the following experimental equation as a function of Weber Number, We2LDu22L and opening ratio m.
    l/D=75m0.5We20.15
    3) The liquid jet containing small solute bubbles has three unstable operating regions, i. e., deformed jet region, flooding region and disintegrated jet region, and there exists an operating region which is limited by opening ratio m, minimum flow rate of liquid (QL) min and maximum flow rate of liquid (QL) max.
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  • Hiroyuki Ozoe, Nobuhiko Sato, Stuart W. Churchill
    1979 Volume 5 Issue 1 Pages 19-25
    Published: January 10, 1979
    Released: May 07, 2010
    JOURNALS FREE ACCESS
    The natural convection of glycerol in a rectangular box 3 cm high, 3 cm deep and 6 cm wide was studied, especially regarding its flow pattern at various angles of inclination. The upper plane of the box is cooled, the lower plane is heated and the four surrounding sides are thermally insulated.
    At the steady state of convection, a small amount of aluminum powder was injected to see the flow mode. At any angle of inclination a peculiar convection mode, a coaxial double spiral movement, so to speak, was found to exist and was photographed. The velocity component in an axial direction of a roll-cell was found to be strong enough to transfer a particle from the roll-end-wall to a central regime of the box even for a quasi-two-dimensional flow at the state of short dimension of the box inclined.
    These findings agreed very well with the theoretical streak lines predicted by our three-dimensional numerical analysis and confirmed it.
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  • Jiro Koga, Kenji Yamaguchi, Ichiro Inoue
    1979 Volume 5 Issue 1 Pages 26-33
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The segregation of particles is one of the most troublesome problems in solid mixing and its mechanism has not been completely clarified.
    This study is concerned with a stochastic approach to the mixing of density-different particle systems in a horizontal drum mixer. The random motion of a particle in the transverse section of the drum can be characterized by the transition probabilities in the radial direction and the circulation time distribution. These characteristic factors for each constituent particle of mixtures were obtained experimentally by use of a particle-tracing method.
    The experimental results of mixing binary density-different particle systems are in good agreement with those of digital simulation based on these characteristic factors.
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  • Shigehisa Endo, Kenji Yamaguchi, Shoichi Okamoto
    1979 Volume 5 Issue 1 Pages 34-39
    Published: January 10, 1979
    Released: February 12, 2010
    JOURNALS FREE ACCESS
    Application of spongy nickel to a filter matrix in magnetic filtration has been examined experimentally with magnetite slurry. Collection efficiencies were measured for seven kinds of unit of 1 cm thickness. A magnetic field of 0.5, 1 and 1.5 kOe was applied by a solenoid. The flow rate was varied from 0.3 cm/sec to 3 cm/sec. With a unit of 108 μm frame diameter, the maximum collection efficiency was greater than 99%. The deposition of magnetite per unit surface area of the matrix was greater than 5 mg/cm2. The nickel sponge is applicable to a magnetic filter matrix. The mechanism of filtration was the standard blocking filtration.
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  • Toshio Tsutsui, Terukatsu Miyauchi
    1979 Volume 5 Issue 1 Pages 40-46
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Various fine particles were fluidized in a 5.2 cm-diameter bed, and the behavior of bubbles was detected with a hot-wire probe. Bubble diameter distribution, mean bubble diameter, and the relationship between ascending velocities and diameters of bubbles were obtained by statistical analysis.
    Fluidized beds with fine particles do not always behave in good fluidity, but broad size distribution and the existence of fines play important roles in improving the fluidity. Even if the surface-volume mean diameters of particles used in fluidized beds are equal, their fluidities are remarkably different when the size distributions of particles are different. Well-prepared particles provide fluid beds with good fluidity free from slugging. An equation to correlate the bubble ascending velocity with bubble diameters in fluid beds is given.
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  • Shin-ichiro Nomura, Tatsuo Tanaka
    1979 Volume 5 Issue 1 Pages 47-51
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Theoretical study is necessary for preventing dust explosions in powder handling. Using the simple dust cloud model presented in the preceding paper, this paper deals with the flame propagation velocity, which is the sum of the burning velocity and the resultant gas expansion velocity. The former can be derived on the basis of the heat transfer theory, while the latter is obtained by calculating the increasing number of moles of gas and the temperature rise of inert gas. The calculated results agree with reported past experience, at least in order of magnitude.
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  • Toshio Fukutsuka, Tetsuo Matsumura, Shuichiro Suda
    1979 Volume 5 Issue 1 Pages 52-58
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    An effective method for restraint of vesication during wet grinding of ferro-manganese by the addition of a corrosion inhibitor to the reservoir in the process has been developed.
    In the wet grinding of ferro-manganese, a large quantity of malodorous foam is produced due to gases liberated by the oxidation reactions between ferro-manganese and water. It is possible to explain these phenomena successfully from the viewpoint of corrosion science.
    As the result of investigations of physical, chemical, and electrochemical considerations with some experiments, it was concluded that the addition of polyphosphate was the most effective solution to the problem.
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  • Masabumi Nishikawa, Noriaki Hashimoto, Shigeo Fujieda, Kenji Hashimoto
    1979 Volume 5 Issue 1 Pages 59-64
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    It was reported by Nagata that impeller level had no effect on power consumption of mixing impellers in turbulent conditions. However, it is known by experience in industry that power consumption of a mixing impeller often varies with impeller level.
    In this report, effect of impeller level on power consumption is studied and correlative equations are given for paddle and turbine impellers in fully baffled condition and non baffled condition in turbulent flow.
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  • Mitsuo Kamiwano, Makoto Hasegawa
    1979 Volume 5 Issue 1 Pages 65-71
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    In this study, the effect on the achievement of homogeneity of the molecular diffusion of low-molecular solute in stirred liquid having approximately Newtonian flow characteristics was examined experimentally.
    An aqueous solution of PVA, in which diffusion of KCl easily takes place, and an aqueous solution of corn syrup, in which it hardly diffuses at all, were used. Mixing rate of the KCl component in both stirred liquids was measured by the electric conductivity method.
    From the results, it was found that α was independent of n in the aqueous corn syrup solution and remained constant in the mixing rate equation :
    nα·TM=const.
    In the PVA aqueous solution, the above equation is found to hold when mixing rates are high, while in the range of low mixing rates the value of α is found to be less than that at high mixing rates.
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  • Tetsu Fujii, Toshihiro Tsuji, Hiroshi Tanaka
    1979 Volume 5 Issue 1 Pages 72-78
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A theoretical analysis is presented of a heat conduction problem in which a solid plate is melted by both external heating and frictional heat in the polymer melt, which is a physical model substituted for the plasticating process of solid polymer in a screwless injection molding machine.
    A few examples of numerical results for low-density polyethylene are shown concerning the temperature distributions within the melted and solid polymer and about the relationship between dimensionless complete melting time and modified power-law Brinkman number. The latter is confirmed by observation of molten features of polymer extruded under various machine variables. Furthermore, it is shown that such data as the maximum value of pressure in stuffer chamber are also correlated by a theoretical maximum extrusion rate, which is defined by the correspondence between the real machine and the physical model for complete melting.
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  • Masato Moritoki
    1979 Volume 5 Issue 1 Pages 79-84
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Experiments of separation and purification were performed on benzene, p-xylene and mesitylene applying the pressure up to 3, 180 kg/cm2.
    The results show that the inclusion of impurities in crystals decreases rapidly with increasing pressure, and the efficiency of purification is much improved. The recovery ratios of the solid component from each binary eutectic mixture are very close to the theoretical values.
    Moreover, highly purified crystals can be easily obtained through repetition of separations of the liquor and partial melting by decreasing the pressure.
    It is suggested that high-pressure fractional crystallization will provide a new type of separation process for substances in various fields in the near future, because of its features of energy savings and high efficiency.
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  • Toshisuke Sasakura, Nobuichi Ohi
    1979 Volume 5 Issue 1 Pages 85-89
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The dissolution processes of a slightly soluble sulfate, CaSO4, in two kinds of aqueous solution of hydrochloric acid and ethylenediaminetetraacetic acid (EDTA) adjusted to pH of 10 were studied experimentally on the basis of mass transfer with chemical reaction between solid and liquid phases.
    The effects of acid concentration on the diffusion flux of Ca2+ for HC1 system are discussed and the reaction factors are found to depend remarkably on the concentration driving force represented by the solubility of CaSO4 in hydrochloric acid solution. The dissolution rates for EDTA system were also promoted by reactant concentration and the results were fairly well explained by correlating with the reaction factors for mass transfer with an instantaneous ir-reversible 2nd-order reaction.
    The concentration-time curves also derived from integral analysis of the rate equations for both systems were compared with the experimental data.
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  • Kunio Kato, Kiyomi Amada, Sachizo Ehara
    1979 Volume 5 Issue 1 Pages 90-95
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Silver catalyst prepared by the thermal decomposition of silver succinic acid in a nitrogen atmosphere has not only high selectivity to ethylene oxide in the synthesis of ethylene oxide from ethylene, but also very steady catalyst activity. In this study, the reaction kinetics for the oxidation of ethylene was investigated with a differential reactor.
    Catalytic oxidation of ethylene consists of the following three simultaneous successive reactions; the oxidation of ethylene to ethylene oxide, the perfect oxidation of ethylene, and the decomposition of ethylene oxide to carbon dioxide. The reaction kinetics of these reactions was analyzed by Langmuir-Hinshel wood kinetic theory with surface reaction rate control, and the reaction rate equations for these reactions were obtained. The calculated conversion of ethylene and yield of ethylene oxide with these rate equations agreed well with experimental conversion of ethylene and selectivity obtained by an isothermal integral reactor.
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  • Teruhiko Sugimori, Yoshihiro Osajima, Yoshijiro Tabara
    1979 Volume 5 Issue 1 Pages 96-101
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    In order to clarify the course of particle formation of precipitated polymer particles, the polymerization of acrylonitrile initiated by redox catalyst system in aqueous solution was carried out batchwise and continuously.
    In batchwise polymerization, the number of polymer particles produced was 6×106particles/cc at the end of 17 min reaction time, decreasing to 106 particles/cc at 30 min, to 105 particles/cc at 70 min. and increasing gradually after that.
    In continuous polymerization, the average particle diameter was decreased and the polymer size distribution became narrow with increased fluid mixing by the ribbon mixer. Furthermore, such tendency was clearly observed especially in the case of increased fluid mixing by the pump impellar.
    Based on these results, the dispersion rate and coalescence rate were obtained. The effects of fluid mixing on the particle are discussed.
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  • Masaaki Suzuki, Atsushi Kanzawa, Mitsuo Kamiwano, Kimio Ohya, Toshisuk ...
    1979 Volume 5 Issue 1 Pages 102-110
    Published: January 10, 1979
    Released: October 21, 2009
    JOURNALS FREE ACCESS
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