KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 7 , Issue 3
Showing 1-19 articles out of 19 articles from the selected issue
  • Toshiro Maruyama, Yoshitsugu Shirasaki, Tokuro Mizushina
    1981 Volume 7 Issue 3 Pages 215-221
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    An experimental investigation was performed to study the mixing of two fluid streams in the developing region of swirl flow in a pipe. The second moment of an experimental temperature distribution in the downstream cross-section of the pipe was used to compare characteristics of mixing over wide ranges of velocity ratio and pipe diameter ratio. Experiments were also made to obtain a trajectory of the deflected wall jet formed by secondary flow injected tangentially to the inner wall of the main pipe. The characteristics of mixing are discussed on the basis of observed behavior of the jet, and the condition for rapid mixing was determined by correlating the results with the swirl number and the momentum ratio, which approximately express swirl intensity.
    It was found that the jet trajectory was well normalized by a momentum length scale. The condition for rapid mixing has the optimum velocity ratio, because an increase in entrainment of the jet with increasing velocity ratio is counteracted by an increase in swirl intensity. The optimal relation falls into a narrow range (0.40.6) of swirl number and is expressible by a constant value (0.7) of the momentum ratio of secondary stream to main stream.
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  • Tatsuo Nishimura, Yuji Kawamura
    1981 Volume 7 Issue 3 Pages 222-227
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Flow pattern in tube banks in the fully developed region was studied. To study the flow near the cylinder surface, diffusional current distribution was measured by an electrochemical method and flow visualization was performed by the hydrogen bubble method.
    Jet flow, formed at a part of the minimum spacing path between adjacent cylinders of the preceding row for the staggered type, reached the cylinder of the aimed row and affected the flow near the cylinder surface, while separated shear flow formed at a cylinder of the preceding row for the in-line type affected the flow near the surface. Also, accelerated flow formed at a part of the minimum spacing path of the aimed row affected the flow near the surface with decrease in pitch ratio, regardless of arrangement of tube banks.
    Macroscopic flow pattern for the in-line type changed remarkably with decrease in pitch ratio, but the flow pattern for the staggered type hardly changed.
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  • Tsutao Otake, Setsuji Tone, Ryoichi Kuboi, Yoshihiro Inoue, Shinji Oga ...
    1981 Volume 7 Issue 3 Pages 228-232
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The characteristics of a non-contacting optical fiber probe for measurement of local velocity and size of a moving particle were studied.
    A two-dimensional response model was developed in which both the surface reflection light and the secondary one of a spherical particle were accounted for. Then the diffuse line light source model was employed to simulate the projected light.
    Basic steric factors were introduced to represent typical particle motions against the probe. As the reflected light intensity was significantly varied due to the steric factors, the standard state for those factors was defined such that the reflected light intensity became the maximum.
    The model could well simulate experimental results and gave a correlation to transform the characteristic length into the size of the particle in the standard state.
    Bubble sizes were measured by applying this correlation to the responses detected by the probe in the bubble swarm. These results were in good agreement with those obtained by photography.
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  • Hisao Tashiro, Kazuo Koyata, Tomoo Yamada
    1981 Volume 7 Issue 3 Pages 233-238
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    This paper discusses a heat flux meter, newly devised to measure heat flux of water tube in thermal power plants, that features greater durability in the boiler furnace, higher accuracy and lower cost. The new heat flux meter is better welded by head solder welding and achieved higher accuracy of measurement.
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  • Yoshiharu Murata, Kazuyuki Yamaguchi, Shigehiro Tanaka, Kazuhito Tamur ...
    1981 Volume 7 Issue 3 Pages 239-244
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Direct contact heat transfer characteristics of the reciprocating plate column were studied.
    The effect of operating conditions and column specifications on the overall capacity coefficient of heat transfer was determined and the following empirical correlation is proposed.
    Ua/CpCρCuC=3.56α0.15 [Ed4/νD3] 0.13 [uD/uC] 2.15m/l] 0.18m/l] 0.12
    whereE=f3αm/l32l
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  • Makoto Nishimura, Michio Kuraishi, Sachio Sugiyama
    1981 Volume 7 Issue 3 Pages 245-252
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The temperature response and the steady state temperature distribution and heat flux for the radiant heating of a one-dimensional semitransparent medium were analysed with consideration of the emission of radiation from the medium. Under the present experimental conditions, the analytical results agreed fairly well with the experimental results, and so the present theoretical analysis was found to be valid. It was found that the effect of internal heating is greatly concerned in the temperature response and the steady-state temperature distribution and heat flux, and that its extent is dependent upon the values of the monochromatic optical thickness of the medium and the monochromatic emissivity of the boundary wall within the main frequency range of incident radiation.
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  • Yuju Sano, Hirornoto Usui, Eiji Saito
    1981 Volume 7 Issue 3 Pages 253-260
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The authors measured the heat transfer coefficient at the outside surface of a helical coil immersed in a mixing vessel with various types of impellers and correlated it with power consumption of mixing per unit mass of liquid.
    The recommended correlation equation is as follows, irrespective of baffled or unbaffled conditions, including previous published data for larger vessels up to 1.2 m diameter in the range of 103<Re<2×106.
    hcodco/λ=0.28 (εdco43) 0.205 (d/D) 0.1 (dco/D) -0.3·Pr0.35·Vis-0.14
    where b=impeller width [m], D=vessel diameter [m], d=impeller diameter [m], dco=outside diameter of coil [m], hco=heat transfer coefficient at outside surface of coil [W/m2·K], Pr = Prandtl number, Re = Reynolds number, d2N/ν [-], Vis=viscosity index [-], ε=energy dissipation per unit mass of liquid [m2/s3], λ =thermal conductivity [W/m ·K], and ν=kinematic viscosity [m2/s].
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  • Nobuyuki Imaishi, Hideyuki Iguchi, Mitsunori Hozawa, Katsuhiko Fujinaw ...
    1981 Volume 7 Issue 3 Pages 261-266
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Absorption rates of CO2 by non-aqueous solutions of cyclohexylamine were investigated experimentally using a liquid jet column and a stirred contactor. Toluene, methanol, methanol-water mixtures and water were used as the solvents.
    In the case of toluene, absorption rates are explained by a model based on the penetration theory. In the other cases, however, observed absorption rates exceeded theoretical predictions because of the onset of interfacial turbulence.
    From the measurement of surface tension of fresh amine solutions and carbonated solutions, the cause of interfacial turbulence is suggested to be a local increase of surface tension due to formation of the salt at the gas-liquid interface.
    To evaluate the effect of interfacial turbulence on chemical absorption, a turbulent diffusivity model is proposed.
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  • Haruhiko Ohya, Yoichi Negishi, Koji Matsui, Kenjiro Kamoto, Haruhiko I ...
    1981 Volume 7 Issue 3 Pages 267-271
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    With sodium hypochlorite reverse osmosis separation under a pressure of 1.0 MPa, deterioration of asymmetric cellulose acetate R.O. membranes (initial acetyl content 39.8%) was accelerated at higher temperature and at higher concentration. The deteriorated membranes have the symptoms of reduction in separation and increase in pure water permeability. Change of chemical composition of membrane material was not observed as a whole, but occurred in the active surface layer. No structural change in the layer was observed, at the scale of the scanning electron microscope.
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  • Haruhiko Ohya, Yoichi Negishi, Koji Matsui, Kenjiro Kamoto, Haruhiko I ...
    1981 Volume 7 Issue 3 Pages 272-277
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Hydrolysis rate of cellulose acetate in the active surface layer may be accelerated by the action of nascent oxygen generated from NaOCl. The decreasing rate of acetyl content may be expressed as a function of the square of the concentration of NaOCl. Activation energy of the rate constant is found to be 70.7 kJ ·mol-1. Concentration of NaOCl in the membrane depends on membrane permeability, which is a function of acetyl content and heat treatment. Change of R.O. separation with time is well anticipated, using heat treatment factor and data of pure water and solute permeabilities corresponding to each acetyl content obtained by Lonsdale et al. This anticipation method can well explain the decrease of separation of sea water R.O. desalination, using Toray's SC-5000 spiral wound modules at the Water Reuse Promotion Center Laboratory at Chigasaki Beach.
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  • Yutaka Hasegawa, Akihiro Hachiya, Toshiyuki Koya, Daizo Kunii
    1981 Volume 7 Issue 3 Pages 278-284
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Single composite pellets made of fine iron are and heavy oil were heated in a vertical silica tube in which nitrogen gas was moving upwards. Production rates of gaseous components and temperature of the pellets were measured. The temperature of the reactor tube ranged from 850 to 1, 050°C, the mixing ratios were 0.18 and 0.20 kg-oil/kg-ore, and the diameters of the composite pellets were 3.5 and 7 mm.
    Gasification of the heavy oil was completed within 120 seconds, and H2, H2O, CH4, C2H4, C2H6, CO and CO2 were obtained as major gaseous products. The mechanism of CO and CO2 formation was found to be different from that of the other gases.
    Sintering and reduction of the fine iron are took place simultaneously with the gasification of the heavy oil, and porous pellets with a reduction degree of 1530% were obtained.
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  • Yutaka Hasegawa, Ikuo Sawada, Toshiyuki Koya, Daizo Kunii
    1981 Volume 7 Issue 3 Pages 285-290
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    A reaction model of simultaneous sintering, reduction and gasification of a single composite pellet made of fine iron are and heavy oil is proposed. The present model is based on the following concept. The reaction of the composite pellet can be divided into two stages, namely the simultaneous gasification of the heavy oil and reduction of the iron are (the first stage) and the reaction between the iron are and the carbon deposited within the pellet (the second stage), where the reaction rate of each stage has different temperature dependency.
    It was found that the profile of CO and CO2 production rate has two peaks when the diameter of the composite pellet is large. Moreover, the ratio of CO and CO2 produced at the second stage was estimated at 70-80% of the total amount of CO and CO2 produced.
    A clue to design calculation of a new process for direct reduction of fine iron are was obtained, wherein simultaneous sintering, reduction and gasification take place.
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  • Kazuhiko Akamine, Shigeyuki Tomita, Eiji O'Shima
    1981 Volume 7 Issue 3 Pages 291-297
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Thermal degradation mechanism of atactic polypropylene was studied with the use of a batch reactor at atmospheric pressure and 355395°C. The yield rate and gas chromatograms of the volatile product were observed. Changes in molecular weight distribution of the reactant were analysed as a function of reaction time. It was found from the chromatograms of the volatile product that the components contained in the volatile product are predominantly produced by intra-molecular reactions. On the other hand, the change in molecular weight distribution of the reactant was found to be explained very well by the random-scission mechanism.
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  • Toshiyuki Yokota, Toshihiko Iwano, Teiriki Tadaki
    1981 Volume 7 Issue 3 Pages 298-303
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    An annular photochemical reactor with mirror wall of outer cylinder has been made to investigate the effect of specular reflection on the light absorption rate in the reactor. The light path lengths of direct rays from lamp and reflective rays from mirror wall were used to estimate the light absorption rate. The photoreduction of potassium ferrioxalate solution was performed in the mirror-wall reactor and the reaction rates were determined for feed concentration varying from 10-7 to 10-5 mol/cm3, using three kinds of reactors with different diameters.
    Good agreement of experimental and calculated reaction rates supported the validity of the estimated light absorption rates, which were used in the calculation of reaction rates. The variation of radiation efficiency of such a mirror wall reactor with change of attenuation coefficient and/or reactor size was also investigated.
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  • Kenji Kubo, Toshiro Aratani, Akira Mishima
    1981 Volume 7 Issue 3 Pages 304-308
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    To clarify the axial liquid mixing characteristics in packed beds, measurements of the residence time curves in beds packed with glass beads of several diameters and 1/2″ ceramic Raschig rings were undertaken. The curves were analyzed by the side mixing model, proposed on the basis of photographic observation of the flow pattern in ordered packed beds and the fit between the curve of model and that of experiment. The parameters of the side pocket model which give the axial mixing characteristics in packed beds are volume fraction of side pocket part and side mixing factor. These two parameters are well correlated with Reynolds number and Galilei number over a wide flow rate range.
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  • Masaaki Ohya, Shinzo Hirasawa, Nobuo Kido, Masakazu Yamazaki, Misao Ka ...
    1981 Volume 7 Issue 3 Pages 309-314
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Experiments of control techniques for NOx by two-stage combustion were carried out with a laboratory size two-stage combustion furnace using town gas, kerosene and heavy oil. We minutely measured the distribution of gas concentration (NO, CO2, CO, H2) and the distribution of temperature in the flame, and studied NO emission characteristics in two-stage combustion.
    The following results were obtained. In modified combustion, emission of NO depends on air ratio. The air ratio which becomes maximum concentration moved toward the airrich side by increasing N content. Generally, this profile is convex under the horizontal axis. In particular, NO was sharply reduced as O2 decreased on the fuel-rich side. In two-stage combustion, NO reduction depends on main air ratio. As main air ratio decreases toward the fuel-rich side, the percentage of NO reduction is increased. Furthermore, the formation of fuel NO is decreased by decreasing air ratio. The rate of conversion of the N content can be reduced by carrying out two-stage combustion.
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  • Hisamoto Furuse, Shuichi Aiba
    1981 Volume 7 Issue 3 Pages 315-319
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Flow behavior of a suspension of yeast cells, Saccharomyces cerevisiae, was analyzed to account for the effects of volume fraction and NaCl addition on apparent viscosity of the concentrated suspension. The suspension exhibited a dilatant flow characteristic. The addition of NaCl to the suspension decreased the cell volume fraction considerably. The relationship between apparent viscosity and cell volume fraction of the yeast suspension in both water and salt solution could be expressed by a semi-theoretical equation. Non-Newtonian flow of the concentrated suspension of yeast cells was simulated by this equation, provided a correction factor to account for collisions between individual particles was introduced.
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  • Michio Morishita, Tomoe Osaki, Shinichiro Gondo
    1981 Volume 7 Issue 3 Pages 320-323
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    A glucose sensor was constructed by covering dissolved oxygen sensor with an immobilized glucose oxidase membrane, and its response characteristics were studied. The basic matrix of the membrane was reconstituted collagen fibrils prepared from hide powder.
    As the amount of glucose oxidase used for immobilization varied from 2 mg to 10 mg per 100 mg of hide powder, profiles of the calibration curve at 25°C changed remarkably to become favorable to the lower glucose concentrations : with a membrane of 10 mg enzyme per 100 mg hide powder the profile of the calibration curve seemed to be usable for glucose analysis even at 5°C.
    The inactivation of enzyme was observed to affect sensor responses seriously at temperatures of 45°C or higher.
    The half-life of the apparent activity of the immobilized enzyme increased with increasing amount of enzyme used and with decreasing temperature.
    The relative value of apparent enzyme activity at time t was found to be formulated by (Et/E0) app=1/ (1 +Ktn). The value of n ranged from 1.7 to 2.7.
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  • Hiroyuki Tanaka, Hiroshi Komiyama, Hakuai Inoue
    1981 Volume 7 Issue 3 Pages 324-325
    Published: May 10, 1981
    Released: November 12, 2009
    JOURNALS FREE ACCESS
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