KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 2 , Issue 3
Showing 1-18 articles out of 18 articles from the selected issue
  • Morihiro Yasuda, Saburo Yasukawa
    1976 Volume 2 Issue 3 Pages 217-221
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    We calculated the flow rate of gas-liquid two-phase flow using the values of the pressure differences between two taps on a cylindrical nozzle, and of the liquid hold-up measured by the method presented in our previous paper.
    First, neglecting the various energy losses due to flow through the contraction section in the cylindrical nozzle, we derived an equation for calculation of the flow rate from a combination of Bernoulli's equation, the equation of continuity and the term of liquid hold-up. However, because these energy losses were not small enough to be neglected, the above equation was corrected with a compensation factor. The compensation factor was determined from the analysis of several hundreds experimental data. The relations between the compensation factor and the liquid hold-up are shown in the diagrams.
    The calculated values obtained by using the compensation factor agree well with the experimentals.
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  • Akihiro Yamanaka, Toyoki Yuki, Nobuo Mitsuishi
    1976 Volume 2 Issue 3 Pages 222-227
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Effects of viscoelasticity on the drag coefficient for creeping flow past a single sphere are investigated.Experimental data are presented for five dilute aqueous solutions of polymer; 0.52 %, 0.86 %, 2.07 %, 2.95% sodium polyacrylate solutions and a 2.01 % methylcellulose solution. A relationship was also obtained by a variational method applied to a Sutterby model fluid. The data for viscoelastic fluids do not fit this correlation based on a purely viscous model such as the Sutterby model. This deviation is expressed by the Weissenberg number based on the maximum relaxation time of Spriggs model fluids, and the drag coefficient is correlated with a modified Reynolds number.
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  • Yoshihiro Iida, Kenichi Takahashi
    1976 Volume 2 Issue 3 Pages 228-234
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Experimental investigation was conducted for horizontal and vertical gas-liquid flow through rectangular channels having narrow spaces of 0.7, 1.6, 3.8 and 10 mm width. Flow patterns were found to be very similar to those in ordinary vertical tubes. In small channels a new flow pattern was observed and called “fissure flow”. A generalized flow pattern map was proposed by which flow patterns were well arranged independently of channel dimensions. The method of Martinelli et al. was used in correlating pressure drop data. The experimental pressure drop factor decreased with decreasing space width. Compensation equations for L-M curves were also presented. The void fraction was measured in channels of 1.6 and 3.8 mm, and the flow parameter was found to be constant at 0.75.
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  • Katsuhiko Muroyama, Kenji Hashimoto, Motoyoshi Toshima, Shinji Nagata
    1976 Volume 2 Issue 3 Pages 235-242
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Measurements were made of axial dispersion coefficient of liquid and liquid holdup in gas-liquid flow through a column packed with spherical particles or Raschig rings.
    The concentration of potassium chloride solution chosen as tracer was successfully measured by a potentiometric method using Ag/AgCl electrode. The parameters in an axial dispersion model were estimated by a nonlinear least squares method from response curves at two axial points for an imperfect pulse.
    Axial dispersion coefficients of liquid phase, Ez, were correlated by
    uLde/Ez=0.156Ψ (Ψ≤4.2)
    uLde/Ez=0.66 (Ψ>4.2)
    where Ψ= (deuLρLL) 0.695 (de3gρL2L2) -0.225
    Liquid holdup data were represented by the following equations for the trickling flow region : αL= {0.13 (Spheres) (0.038/ε) dp-1 (Rings)} +28.8 (deGLL) 0.876 (de3gρL2) -0.608
    and for the pulsing and the bubbling flow regions :
    αL=0.138 (αs/ε) 1/3χ0.24
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  • Ryuzo Ito, Yuushi Hirata, Kazuhiko Ishihara, Tamio Shigenobu, Koichi M ...
    1976 Volume 2 Issue 3 Pages 243-249
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Process of deformation and breakup of droplets, which plays an important role in mass transfer and chemical reaction in a dispersed liquid system, was studied experimentally in steady and unsteady shear fields generated in the annular space between two coaxial rotating cylinders.
    In steady shear field, four patterns of deformation and breakup are characterized according to the viscosity ratio of dispersed and continuous liquids, and the critical shear rate required for breaking up a droplet and its deformation vary with viscosity ratio. The orientation of deformed droplet was correlated with the viscosity ratio and the degree of stationary deformation.
    In a step change of shear field, two patterns of unsteady deformation process were observed. In a system of low viscosity ratio, the unsteady deformation process does not oscillate with time and the time dependence of deformation can be estimated by a equation derived semi-theoretically. On the other hand, the unsteady deformation process oscillates with time in a system of high viscosity ratio and the periodic time has been correlated with the Weber number.
    The necessary and sufficient conditions of shear rate and loaded time required for breaking up droplets have been determined under the step change of shear field and the numbers of broken droplets have been correlated with excess shear rate and the loaded shearing time.
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  • Fukuji Yamashita, Hakuai Inoue
    1976 Volume 2 Issue 3 Pages 250-255
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Generation, rising, breakup and coalescence of bubbles in a two-dimensional bubble column were observed by 16 mm cinecamera, and their mechanisms and kinetics were studied.
    From observation it was found that at low gas flow rate breakup of large bubbles started only from their upper surfaces, but at large gas flow rate and in vigorous mixing breakup from the lower surfaces also occurred. Time of both breakup and coalescence was about 0.1 sec at low gas flow rate.
    Based upon such observations, a simple model of the performance of bubble columns is presented, and the equation for gas holdup in a slug flow region is derived. The equation shows good agreement with the experimental data of the authors and of previous work. It was also shown that the coefficients of the equation have reasonable physical meanings, and are quite consistent with experimental values.
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  • Akihiko Murakami, Akio Misonou, Kenji Inoue
    1976 Volume 2 Issue 3 Pages 256-261
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    By using three rotating-disc contactors with different inside diameters, 7.9, 10.5 and 30 cm, the effects of column geometry, flow condition and disc rotation upon dispersed-phase holdup have been studied. MIBK-water system and kerosene-water system with and without mass transfer were used in the present work.
    A new correlation based on dimensional analysis was presented. This correlation was in good agreement with the experimental data in the literature as well as with the data in this work.
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  • Hisahiko Watanabe, Terukatsu Miyauchi
    1976 Volume 2 Issue 3 Pages 262-265
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The rate of iodine permeation through a porous Teflon diaphragm, impregnated with poly (dimethylsiloxane) (PDS), was measured at 25.0°C. The obtained overall mass-transfer resistance was divided into two parts, namely the resistance of the liquid membrane and that of a boundary layer, by means of a Wilson plot. It was found important in the design of a diaphragm-type liquid membrane extractor to reduce the mass-transfer resistance of a boundary layer. The diffusion coefficient of iodine in PDS bulk was obtained by using cyclohexane as a standard material. The diffusion coefficient shows a very gradual decrease compared with the case for non-polymeric medium, when the molecular weight of medium material becomes large; in the end, it no longer decreases but remains constant.
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  • Hikoji Inazumi, Takanori Suzuki, Kenichi Kato
    1976 Volume 2 Issue 3 Pages 266-271
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Methods of experiments and calculations for the isothermal adsorption of one adsorbate component from a binary gas mixture on fixed beds were presented, based on a model in which a nonlinear adsorption isotherm and simultaneous mass transfer in the pore system of the solid and in a film surrounding the particles are considered.
    Adsorption experiments of n-butane from nitrogen-n-butane mixture on a differential fixed bed of activated carbon spheres were carried out.
    The mass transfer coefficients on the surface of adsorbent particles and the effective diffusivities in the adsorbent particles were obtained using an improved curve fitting method for the isothermal adsorption.
    Then breakthrough curves for the adsorption of the same system on packed beds of the same adsorbent particles were obtained experimentally, and the results were compared with the results calculated using the mass transfer coefficients on the surface of adsorbent particles and the effective diffusivities in adsorbent particles.
    The estimated values of the breakthrough curves agreed well with those obtained experimentally, so the validity of this method of design calculations was verified.
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  • Keiichi Kato, Issei Nakamori
    1976 Volume 2 Issue 3 Pages 272-276
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Foam separation experiments were carried out in FeCl3-sodium lauryl sulfate (LNa) system in HCl acid solution, and the Langmuir adsorptive model was well fitted to the adsorption of iron ion independently of critical micelle concentration (CMC) and to the adsorption of LNa within CMC. It was estimated that iron ion hydrolyzes near the gas-liquid interface and Fe (OH) 2+ is adsorbed, and surface excess of iron is calculated by the Gouy-Chapman theory of the diffusion double layer.
    The calculated values were in fair agreement with the experimental values within CMC and the authors got clues to the estimation of the metal ionic surface excess with complexes formation.
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  • Isamu Maeda, Ituo Tanaka
    1976 Volume 2 Issue 3 Pages 277-281
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The results of experimental study on characteristics of a roll feeder for moving beds are as follows :
    (1) The discharge rate is in proportion to the revolving speed of the roller and is not in proportions to height of the slit.
    (2) To reduce the crush and abrasion of particles, the height of the slit is required to open more than a limit for mechanical blockage of particles.
    (3) Installation of a moderate rectification part between the moving bed and the discharger is preferable to form a uniform particles flow in the bed.
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  • Isamu Maeda
    1976 Volume 2 Issue 3 Pages 282-285
    Published: May 10, 1976
    Released: October 21, 2009
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    The results of experimental study on effect of rectifying boards and plates for moving beds are as follows :
    1) Installation of a rectifying board is preferable to prevent piping, but it is not satisfactory for forming a uniform particles flow in the bed.
    2) Installation of a rectifying board and plate together form a uniform particles flow in the bed.
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  • Hiroaki Masuda, Hiroshi Kurahashi, Mitsuaki Hirota, Koichi Iinoya
    1976 Volume 2 Issue 3 Pages 286-290
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A micro-feeding method is studied with a modified table feeder. The table feeder examined has either two or three scrapers, and can feed such small amount of powders as several mg/s. Precision of feeding is tested with particular attention to characteristics of the feeder and properties of powders discharged. Powders used in the experiment are quartz sand, talc, calcium carbonate and others covering a wide range of flowability. Furthermore, with respect to testing methods of a feeder, the effect of sampling period on the precision is studied both experimentally and theoretically. As a result, variation of precision with sampling period becomes clear even when the powder flow rate has a periodic fluctuation.
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  • Tadashi Shirostuka, Kiyotaka Sakai, Akira Tanaka, Hiroshi Ozawa
    1976 Volume 2 Issue 3 Pages 291-297
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Tangential combustor using propane-air mixtures was utilized to investigate the formation of thermal NOx and the effect of water - spray on NOx reduction. Measurements of temperature and NOx concentration in combustor were made in detail along both axial and radial directions, so as to comprehend the correspondence of NOx formation with gas temperature and the effect of water spray on the temperature distribution in the combustor, which strongly affects NOx formation.
    Combustor for this work was made to prevent back-mixed flow as far as possible, so that NOx formation in post-flame gas could be distinguished from that in primary reaction zone. As a result, for the former, formation of NOx could be expected to follow the Zeldovich mechanism and, for the latter, NOx formation was independent of gas temperature and consequently no effect of water spray on NOx reduction was observed.
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  • Toshiyuki Yokota, Toshihiko Iwano, Teiriki Tadaki
    1976 Volume 2 Issue 3 Pages 298-303
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    To estimate the light intensity distribution and the volume-average light intensity in an annular photochemical reactor, a surface source light distribution model was proposed. It has been assumed for the model that radiation from a lamp surface which has a spherical light distribution characteristic reaches into the reactor.
    The experimental results of light intensity distribution measured by a CdS cell agreed well with those from the model. Also, the average light intensity estimated from the photoreduction rate of potassium ferrioxalate was compared with the theoretical prediction. The scale-up experiments for exposure length of lamp and radial distance of reactor supported the validity of the model.
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  • Takuo Sugawara, Kohta Omori, Hiroyasu Ohashi
    1976 Volume 2 Issue 3 Pages 304-309
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The effects of light absorption by a product (or an intermediate) R and diffusion rates of R and a reactant A on the reaction characteristics of a batch or a laminar flow plate-type photochemical reactor have been studied theoretically under conditions of the weak absorption of light by A and the irradiation of monochromatic parallel light, where the reaction A→R or A→R→S occurs.
    In the case of A→R, the influence of diffusion rate is more pronounced at the more effective internal light filtering : the slower the diffusion rate, the lower is the average conversion under constant radiant intensity. This effect is much enhanced in a flow system because of the velocity distribution.
    As for the characteristics of flow reactor in which the photoconsecutive reaction takes place, the extent of the conversion of A becomes less as the quantum yield of the second step of reaction is lower. The selectivity of the intermediate R is slightly decreased with slower diffusion rate and is insensitive to the extent of internal light filtering.
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  • Masanori Fujitsu, Masanobu Hasatani, Sachio Sugiyama, Fukuji Isono
    1976 Volume 2 Issue 3 Pages 310-316
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The transient thermal stress in insulating-refractory materials, which is one of the causes of deformation or cracking of these materials, was theoretically analyzed by the finite element method assuming that the plane strain model is valid.
    As a result, the following conclusions were obtained :
    (1) The calculated values of the temperature profile in the materials showed fairly good agreement with the measured values.
    (2) As for the reaction force, the calculated values corresponded well to the measured values, and it was made clear that this analytical method can be applied to transient thermal stress analysis of insulating - refractory materials with good satisfaction.
    (3) The maximum stress (calculated) which breaks out in cracking showed values nearly equal to those of the modulus of rupture and compression as measured by the method defined by JIS, and this analytical method was therefore judged to be applicable for evaluating the conditions of deformation and cracking.
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  • Masayuki Sato, Takeshi Sakai, Kunio Kataoka, Tohru Takami, Yoshihiko K ...
    1976 Volume 2 Issue 3 Pages 317-324
    Published: May 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
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