KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 4 , Issue 4
Showing 1-18 articles out of 18 articles from the selected issue
  • Tsutomu Hirose
    1978 Volume 4 Issue 4 Pages 331-336
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The proposed method is based on the idea that independent dimensions can be chosen according to the nature of phenomena in question. The most informative result is obtained in three steps, i. e. STEP 1) Use the II theorem and derive the dimensionless products in a system with the minimum number of dimensions. STEP 2) Increase the number of dimensions by introducing appropriate dimensional constants and rewrite the dimensionless products in the new dimensional system. STEP 3) Eliminate the dimensionless products which include the dimensional constant introduced above if a change in its numerical value has no influence on physical phenomena.
    This simple method is applicable to many problems described both with and without differential equations. The derived result is not restricted to a “normalized” solution but extends to a “similarity” solution. Thus the proposed method is as useful as a group theoretic and other available methods in analysing phenomena of directional characteristics such as boundary layer.Illustrative solutions are given to some classical problems.
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  • Yutaka Hagihara
    1978 Volume 4 Issue 4 Pages 337-341
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Experiments on evaporation of simple systems of di (2-ethylhexyl) phthalate (EHP) and m-tricresyl phosphate (m-TCP) and on distillation of EHP-m-TCP binary system were made in a range of pressure from 1.0 × 10-3 to 3.5 × 10-1 mmHg by use of a pot still. The results obtained show the following facts; 1) In the domain of evaporation without molecular-burst-evaporation, the values of relative volatility are equal to the theoretical value. At the threshold of molecular-burst-evaporation, a deviation of relative volatility from the theoretical value occurs, and at the point of completion of molecular-burst-evaporation the value of relative volatility is a minimum. From the viewpoint of separation, it is advisable to avoid the occurrence of molecular-burst-evaporation as much as possible. 2) The threshold temperatures of molecular-burst-evaporation of a binary system are lower than those of simple systems. 3) In a range of mole fraction in liquid from 0.45 to 0.50, evaporation rate of lighter component (EHP) has a maximum and evaporation rate of heavier component (m-TCP) has a minimum. But the effect of liquid concentration on evaporation rate is smaller than that of liquid surface temperature.
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  • Masahito Sato, Fumikazu Ikazaki, Shigeki Toyama
    1978 Volume 4 Issue 4 Pages 342-349
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A simulation program of a multistage flash evaporator (MSF) to desalt sea water in partial load operation was developed. The simulated static characteristics were compared with experimental results obtained from a test plant having a capacity of 3, 000 m3/d, and the following points were clarified. 1. Ineffective flashing may take place at low-temperature stages when the load is decreased below a limit. 2. The number of such stages increases with decreasing load. 3. The performance ratio at partial loading is evidently decreased due to the ineffective stages. 4. The difference of brine levels between stages becomes larger in the ineffective stages than in the others. 5. The brine level at the eighth stage was observed to change sharply with load change. This tendency may suggest the existence of a constraint to stable operation.
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  • Katsutaka Nakamura, Takashi Watanabe
    1978 Volume 4 Issue 4 Pages 350-354
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    In the theoretical analysis of axial downward flow in the vertical agitated thin film evaporator with any number of fixed blades, novel work was presented by Kern and Karakas. But they dealt only with the case of large volumetric flow rate in which liquid fillets were always built in front of the blades. Under the condition that thermal effects were excluded, we derived some theoretical equations which are also valid at volumetric flow rates smaller than the critical one. These equations are compared with the non-dimensional expressions of former experimental results.
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  • Yukimichi Okamoto, Masabumi Nishikawa, Kazuhide Matsuda, Kenji Hashimo ...
    1978 Volume 4 Issue 4 Pages 355-360
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Turbulent diffusion coefficients are impossible to obtain from diffusion experiments in baffled mixing vessels. Thus results of turbulence measurements using a hot-film anemometer were employed in this study for calculation of the coefficients. In this calculation, a relation between Lagrangian scale and Eulerian scale of turbulence was assumed.
    Measurements were taken in baffled and unbaffled mixing vessels to obtain distributions of the coefficients in these vessels. Experimental evidence showed direct proportionality of the coefficients to Reynolds number of agitation, Re, in both baffled and unbaffled vessels. Values of the coefficients obtained in the unbaffled vessels in this study were in fair agreement with those obtained from diffusion experiments by Yamamoto, though considerably smaller in the Re range below 50, 000.
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  • Masayuki Toda, Jun Yonehara, Siro Maeda
    1978 Volume 4 Issue 4 Pages 361-365
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The solid-liquid two-phase flow in a horizontal pipe was studied experimentally. The solid particles used in this experiment were spherical glass, nonspherical glass, calcite, and basic lead silicate. The investigation concerned pressure drops and transport concentrations of solids.
    Two different types of pressure drop corresponding to the flow patterns were found in the region of modified Froude number less than I. In this region the pressure drop equation for the moving bed was not applied. An empirical equation expressing the pressure drop for the moving bed with stationary bed is proposed.
    In the case of the moving bed with stationary bed, the ratio of transport concentration to delivered concentration, CT/CS, tended to increase with decreasing mixture velocity. On the other hand, in the case of rod-like flow or pulsed phase flow CT/CS was found to decrease with decreasing mixture velocity.
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  • Hirotaka Konno, Masafumi Kuriyama, Masahiro Asano, Eiji Harada
    1978 Volume 4 Issue 4 Pages 366-371
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The effect of corona discharge on heat transfer from heated copper pipes in air was studied experimentally. Thick-walled copper pipes of 10, 20, and 40 mm diameter were used for the heat transfer section. Discharge electrodes were needles impressed with negative high voltage.
    Corona wind velocity was found to be proportional to the square root of corona current independent of the gap and pitch of needle electrodes. The ratio of local velocity to maximum velocity of corona wind was expressed by the function of x/H (x : distance from the center of test section; H : gap).
    Heat transfer rate under corona discharge increased with increasing gap and with decreasing pitch. However, heat transfer rate was not affected by the pitch p, or by gap H at ratios H/p above 0.7. Average Nusselt number was found to be proportional to the n-th power of the square root of corona current.
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  • Tatsuro Sawada, Tetsuji Chohji, Shojiro Shimada
    1978 Volume 4 Issue 4 Pages 372-376
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Effects of temperature shift-down on the growth of Escherichia coli BB were investigated in continuous cultures. Dynamic behavior observed could be simulated well introducing a function with lag time to Monod's equation.
    In the presence of enough glucose in media, the growth rate changed instantly, without any change in DNA content of a cell, with a sudden shift in growth temperatures. At the limiting glucose concentration, changes in growth rate and DNA content of a cell were not seen immediately but were appreciably delayed. The values of lag constant appeared to related closely to a difference in DNA content of a cell at initial and final steady state, so that the time required to reach the new growth state increased with larger difference in DNA content.
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  • Shigeharu Morooka, Kiyoshi Ikemizu, Yasuo Kato
    1978 Volume 4 Issue 4 Pages 377-380
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The rate of ozone decomposition in water was measured in the range of temperature 3 to 35°C and pH 2 to 9. The following empirical equation was obtained.
    -dC/dt=ka0 [OH-] 0.28C1.5+kb0 [OH-] 1.0C1.0
    where ka0=4.6×1013exp (-17.9×103/RT)
    kb0=1.8×1018exp (-20.6×103/RT)
    C=ozone concentration [mol/l], [OH-] =OH- ion concentration [mol/l], R=the gas constant [cal/mol·°K], T=absolute temperature [°K] and t =time [sec].
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  • Masaaki Suzuki, Atsushi Kanzawa
    1978 Volume 4 Issue 4 Pages 381-385
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The data of the recombination coefficient of ion and electron are required to investigate the mechanism of heat transfer between a thermal plasma flow and materials, such as appears in the plasma furnace, etc. So far there are few data for the recombination reaction in a collision-dominated plasma such as a thermal plasma.
    In the present work, the recombination reaction was investigated by measuring the decrease of charged particle density in a weakly ionized argon plasma flow at atmospheric pressure. From this experiment, it was found that the volume recombination coefficient is of the order of 10-13 m3·s-1, which implies a dissociative recombination mechanism. It was also found that a recombination reaction occurs on the surface to some extent, though the surface is not fully catalytic.
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  • Tadashi Shirotsuka, Masao Sudoh
    1978 Volume 4 Issue 4 Pages 386-393
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    To discuss the influence of non-uniform distribution of light-induced chain reaction, experiments were carried out on photosensitized polymerization of methyl methacrylate in a partially illuminated photoreactor with different stirring speeds and different illuminated volumes. Theoretical analysis was made by a dimensionless formula of light zone and dark zone with the recirculation model proposed. From analyses of the experimental results of initial polymerization rate, number average degree of polymerization and molecular weight distribution in low polymerization-conversion, the effectiveness of a calculation formula using the circulation time distribution in a photoreactor is discussed. The experimental values agreed relatively better with the predicted ones in larger illuminated areas.
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  • Tadashi Shirotsuka, Masao Sudoh
    1978 Volume 4 Issue 4 Pages 394-399
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Experiments on dye-sensitized photodecomposition of aqueous phenol using visible light energy were carried out in a bubble column illuminated from outside by eight tungsten lamps. Volume mean light absorption rate was theoretically formulated as a simple equation of the model in which light propagates radially into the reactor axis.
    From the results of the initial decomposition rate of phenol, average quantum yield was obtained with methylene blue, rose bengal and eosin Y at pH=10, gas flow rate U=4.35 cm3/ sec. The retardation of reaction is discussed and is explained well by the reaction mechanism proposed.
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  • Eiji Obata, Haruo Watanabe
    1978 Volume 4 Issue 4 Pages 400-405
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Continuous thickener operation was studied using the batch settling curve of a feed slurry instead of the solid flux curve, which is a function of solid concentration. The method is an extended development of Talmage-Fitch's method based on Kynch's theory.
    The analysis in this paper enables one to predict graphically concentration distributions and optimum operating conditions in a thickener at steady state. The concentration distributions predicted by this method agreed well with experimental results for calcium carbonate slurries over a wide range of underloading or overloading operations. The batch settling curve method is superior to the solid flux curve method since the former can be used more easily than the latter.
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  • Mitsutaka Kawamura, Shigeki Toyama, Kunio Uchida
    1978 Volume 4 Issue 4 Pages 406-412
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A feeder suitable to a shaft furnace for pyrolysis of municipal solid wastes has been developed. It has a compression chamber and ram mechanism. Mechanical properties of the wastes necessary for feeder design are clarified by testing performance of the developed feeder. The wastes show two different types of behavior as compression pressure increases. At first the waste particles move into interparticle vacancies while the pressure increases slowly, and then the particles themselves undergo shrinkage where the pressure increases rapidly. The relationship between pressure and volume shrinkage in the latter period can be expressed by Kawakita's equation. Releasing the pressure, the shrunken wastes reveal restorable properties and still show elastic deformation when 80 Kg2/cm pressure is imposed upon them. The pressure required to push the compressed wastes through a cylindrical chamber upward is smaller than 3 Kg/cm2 when the moisture content of the wastes is more than 60 %.
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  • Jiro Koga, Kenji Yamaguchi, Ichiro Inoue
    1978 Volume 4 Issue 4 Pages 413-418
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The theory of Semi-Markovian Process is applicable to the transverse mixing-demixing of solid particles in a horizontal drum mixer. The motion of solid particles can be characterized by the transition probabilities in the radial direction and the circulation time distribution. These characteristic factors were determined experimentally for several kinds of spherical particles.
    Based on these factors, the spatial distribution of tracer particles in the equilibrium mixture was obtained theoretically and was transformed into the concentration distribution.
    The results for two constituents of different densities showed that lighter particles have a tendency to segregate toward the outer side of the circulating flow, while heavier ones have a tendency to concentrate in the neighbourhood of the stagnant point.
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  • Hideto Yoshida, Kenji Fujii, Yoriyuki Yonemoto, Hiroaki Masuda, Koichi ...
    1978 Volume 4 Issue 4 Pages 419-424
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Theoretical studies of separation efficiency of a virtual impactor have been conducted. It is found that the inertia parameter of 50 % partial separation efficiency becomes smaller as the ratio of slit width to pipe radius decreases, while it becomes larger as the ratio of straight to total flow rate or the flow Reynolds number in an inlet pipe decreases. Thickness of the pipe wall at the slit does not affect separation efficiency. Experiments are carried out by using 3 to 4 μm monodisperse methylene blue-uranine aerosol generated by a spinning disk. These experimental results agree well with the calculated values obtained by use of a potential flow model. The classification performance is slightly inferior to that of a conventional impactor. It is also observed that the amount of particles deposited at the inlet tip of straight-through pipe is not negligible under some operating conditions.
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  • Kenichi Ushiki, Kiyokazu Kubo, Shigeki Hirano, Koichi Iinoya
    1978 Volume 4 Issue 4 Pages 425-430
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Inertial and gravitational collection efficiencies of particles with a ribbon perpendicular to the flow are calculated theoretically.
    In downward or horizontal flow, all particles are collected within two limiting particle trajectories, which come in contact with the side edges of a ribbon. However, this is not always true in upward flow. Efficiencies in upward flow have a maximum value similar to the case of a disk or a cylinder. These decrease much more sharply at upper and lower limiting inertial parameters than in horizontal and downward flows. When particle drag deviates from Stokes' law, the range of inertial parameter in which particles can be collected widens.
    In downward flow, collection efficiencies change monotonously with inertial parameter, and the rate of change increases as Froude number decreases. However, this tendency becomes smaller when the deviation from Stokes' law becomes larger.
    The efficiencies in horizontal flow increase as Froude number decreases. However, sometimes the opposite tendency takes place when the deviation from Stokes' law is larger.
    Most of the experimental results agree well with the theoretical curves.
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  • Tsutomu Hyodo, Akira Yamanaka, Kazuo Kondo, Fumiyuki Nakashio, Takeshi ...
    1978 Volume 4 Issue 4 Pages 431-438
    Published: July 10, 1978
    Released: October 21, 2009
    JOURNALS FREE ACCESS
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