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Predecessor
Volume 6, Issue 1
Displaying 1-14 of 14 articles from this issue
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Kazumi Sato, Hisato Osuka, Ichiro Inoue1980 Volume 6 Issue 1 Pages 1-7
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSThe maximum penetration distance of a vertical buoyant jet issuing into an ambient fluid with a density interface was investigated analytically and experimentally.
The maximum penetration distance was correlated to issuing conditions and density distribution of ambient fluid by adopting an integral representation of the governing equations.
The coefficients involved in the correlation equation were examined experimentally.
As a result, it was found that the coefficient connected with the jet width agreed with the value suggested from Rouse's experiments. A few corrections were necessary for the partial collapse of similarity on the density difference distribution due to a density interface.View full abstractDownload PDF (1167K) -
Hidetoshi Aoki, Norio Yamakawa, Shigemori Ohtani1980 Volume 6 Issue 1 Pages 8-14
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSThe convective heat transfer coefficients around a cylinder in cross flow were locally measured under frosting conditions. The local heat fluxes around the cylinder were determined by measuring the radial temperature distribution in a thick cylinder having many small drilled holes in which thermocouples were inserted, and by drawing the isothermal lines for the cylinder.
Experimental data showed that the variations in the heat transfer coefficients around the frosting cylinder qualitatively matched those of the flow pattern around it, and that the values were from 1.2 to 2.0 times larger than those without mass transfer around the smooth cylinder, because of the interference of heat and mass transfer and the frost surface roughness.
Furthermore, in the region of low Reynolds number, the values of the mean overall heat transfer coefficients from air to the heat transfer surface in frosting process became larger than those of the smooth cylinder without mass transfer, in spite of the existence of thermal resistance of the frost layer. The reason was considered to be the relatively great roughness of the frost layer in the low Reynolds number region, which caused an increase of heat transfer area and a disturbance of the boundary layer.View full abstractDownload PDF (1167K) -
Satoru Kato, Hikoji Inazumi, Takanori Suzuki1980 Volume 6 Issue 1 Pages 15-22
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSExperiments on vaporization of binary solutions into a turbulent air stream were carried out in a wetted-wall column. The results obtained from these experiments were as follows.
When the concentration of the diffusive components in gas phase are dilute, the effects of the key diffusive component on the mass transfer rate of the other diffusive component through diffusion flux are small. But when a large difference exists between the transfer rates of diffusive components, significant effects of the component which has the larger transfer rate appear on the transfer rate of the other diffusive component through bulk flow. For such cases, a correlation factor which relates mass transfer rates in ternary gas systems including one non-diffusing component to those in binary systems was developed and the relation among those quantities was determined. Estimated values of mass transfer rates of each diffusive component based on this relation showed fairly good agreement with observed values.View full abstractDownload PDF (1390K) -
Atsushi Ikari, Yasuo Hatate1980 Volume 6 Issue 1 Pages 23-27
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSThe plate efficiency of a minor component is requisite to predict the behavior of that component in distillation.
By use of an Oldershow-type column, continuous rectification of an azeotropic mixture of ethanol and water containing a minute amount of furfural was carried out under various conditions. The concentrations of the minor component in distillate and bottoms were obtained.
An equation describing the ratio of the concentration of a minor component in distillate to that in bottoms was derived. The Murphree vapor efficiencies were determined so as to fit the calculated ratios to the experimental ones.
Plotting efficiencies against vapor rate shows that efficiencies are within the limits of 0.7 to 0.8 at vapor rates higher than about 35 g·cm-2·h-1. When the vapor rate becomes lower than that, however, the data are scattered.
In the system described in this paper, the value of efficiency of the minor component at higher vapor rates is comparable to that obtained for a major component by the conventional method.View full abstractDownload PDF (842K) -
Takamasa Aonuma, Yasuo Nakaike, Toshihumi Amemiya1980 Volume 6 Issue 1 Pages 28-32
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSWhen water containing dissolved gas at high pressure flows through porous media having pores of colloidal dimensions, the flow rate of water increases. In this experiment, membranes made of fine silver particles and Nuclepore membrane, which has straight-through cylindrical pores, were used as porous media.
The effects of dissolved gas on the flow rate of water through a medium depends on the pore diameter (hydraulic diameter), the concentration of dissolved gas and the material of the membrane, but does not depend on the kind of gases under these experimental conditions. An empirical equation for the flow rate of water containing dissolved gas through porous media was obtained.
When water containing dissolved gas flows through porous media, gas bubbles appear at lower pressure and adhere to the pore surface. This suggests that slippage takes place at the pore surface by micro gas bubbles, so that the flow rate of water increases.View full abstractDownload PDF (710K) -
Takaji Akiya, Masaru Ôwa, Ichiro Hayano, Shigetake Kawasaki1980 Volume 6 Issue 1 Pages 33-39
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSFor the purpose of scale-up of a NaOH·3.5H2O crystallizer employing the secondary refrigerant freezing method, the crystallization of NaOH-3.5H2O from the NaOH-KOH-NaCl-H2O system was studied with two sizes of crystallizer, in which Freon-12 was used as secondary refrigerant.
The nucleation rate and the crystal growth rate were compared with those obtained in the previous study by the indirect freezing method, using a laboratory-scale crystallizer.
Crystal growth rate was unaffected by crystallizer size and freezing method, but a difference of nucleation rate was found between the different freezing methods. The nucleation rate was found to be proportional to the second order of the suspension density and the reciprocal crystal growth rate. From this analysis, the operating diagram of a crystallizer to produce NaOH·3.5H2O from the NaOH-KOH-NaCl-H2O system was obtained.View full abstractDownload PDF (1108K) -
Shigeharu Morooka, Katsuki Kusakabe, Takanori Watari, Yasuo Kato1980 Volume 6 Issue 1 Pages 40-45
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSCharacteristics of a rectangular fluidized bed electrode with solid copper particles or copper-coated glass particles were studied, using the electrodeposition of copper from aqueous CuSO4-H2SO4 solutions. The experiments were carried out over a CuSO4 concentration range of 0.01 to 0.05 mol/l, a H2SO4 concentration range of 0.1 to 1.0 mol/l, and a bed expansion range of 10 to 35%. The diameter of solid copper particles and copper-coated glass particles was in the range of 120 to 670 μm and 790 to 1, 030 μm, respectively.
Results show that the rate of charge transfer in the fluidized bed electrode depends on the electrode reaction rate, the effective specific resistance of solution phase, and the effective specific resistance of particle phase, ρm. The value of ρm is independent of CuSO4 concentration and H2SO4 concentration, but increases with increase in bed expansion. The dependence of ρm on bed expansion for solid copper particles is larger than that for coppercoated glass particles. Current efficiencies in these experiments were greater than 90 %.View full abstractDownload PDF (1062K) -
Hiromitsu Kojima, Koichi Asano1980 Volume 6 Issue 1 Pages 46-52
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSMeasurements were made of the distribution of solid particle concentration, bubble diameters and gas hold-up in a suspension-bubble column for gas flow rate of lower range than the critical gas flow rate.
Based on observed solid-particle concentration distribution and with the aid of a one-dimensional dispersion model, correlations for vertical solid-particle concentration distribution were proposed which also made it possible to predict the amount of unsuspended particles on a gas distributor.
By considering the effect of an unsuspended dense-particle layer on the gas distributor, a semi-empirical correlation for bubble diameter in a suspension-bubble column was proposed.
By considering the relation between gas hold-up and bubble diameter, a correlation for the gas hold-up in a suspension-bubble column was proposed as a function of gas hold-up in a bubble column and bubble diameters.View full abstractDownload PDF (995K) -
Tadashi Shirotsuka, Masao Sudoh, Hiromi Fukawa1980 Volume 6 Issue 1 Pages 53-58
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSTo study the superiority of applying photochemical reaction to a system which is operated preferably at lower temperatures, photooxidation of benzaldehyde in liquid phase was made by using a bubble column photo-reactor illuminated from outside. The yield of perbenzoic acid was analysed experimentally and theoretically. Overall reaction rates were obtained for photodecomposition of perbenzoic acid. The yield of perbenzoic acid was increased in the region where chemical reaction was the rate-determining step with the light intensity as low as possible.View full abstractDownload PDF (798K) -
Michitaka Suzuki, Kazutaka Makino, Masaharu Yamada, Koichi Iinoya1980 Volume 6 Issue 1 Pages 59-64
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSTo study the structure of particle arrangement in a three-dimensional particle system, it is necessary to analyse the number of contact points on a particle, that is, the coordination number. In this paper a new equation, which gives the correlation between the average coordination number and the void fraction of a random-packed monosize particle system, is derived from an approximate analysis of the probability density distribution of the first-layer particles, in which a coordination number with hexagonal close packing of 12, at void fraction =0.2595, is used as a boundary condition of this equation.
The theoretical curve is in good agreement with both three-dimensional computer simulation results and previously published experimental values which are considered to have a smaller error of measurement.View full abstractDownload PDF (963K) -
Satoshi Okuda, Hiroshi Takano, Yoshihiro Tonomura, Mitsuo Takaya, Masa ...1980 Volume 6 Issue 1 Pages 65-69
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSThe electrical charge on a moving single particle in the air can be determined by integrating its induced current on a measuring electrode with time. In this experiment, a circular plate and a sphere are used for the measuring electrode. For the sample particle, a charged water droplet is produced from a fine tube where high voltage is directly applied in order to obtain a certain constant value of electrical charge.
Judging from the good agreement with the experimental data measured by the Faradaycage method, it is considered that the proposed method should be applicable to measurement of particle charge.View full abstractDownload PDF (749K) -
Shinichi Yuu1980 Volume 6 Issue 1 Pages 70-78
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSParticle turbulent diffusivity εpr in a horizontal circular pipe is calculated based on a model in which the fluid intensity is constant over the fluid integral time scale. Substituting εpr into the three-dimensional particle diffusion equation, the dust concentration distributions are obtained by solving it numerically.
Dust concentration distributions were measured by using a photoelectric dust counter and a weighing method (dust tube method). Fly ash was used for the dust.
The results indicate that the calculated dust concentration distribution based on the reflection wall model expresses well the measured distribution of fly ash. However, the fact that in the horizontal distribution a high-concentration region is formed near the pipe wall is not explained by the reflection wall model alone. It seems attributable to the frequent re-entrainment of the deposition dust on the pipe wall.View full abstractDownload PDF (1330K) -
Tetsuji Chohji, Tatsuro Sawada, Sigeru Kuno1980 Volume 6 Issue 1 Pages 79-86
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSThe growth-inhibitory and lethal effects of ethanol, phenol, Cu++and Zn++ on a respiration-deficient mutant of Saccharomyces cerevisiae and Escherichia coli BB were investigated in batch cultures, by measuring total cell number, viable cell number and macromolecule contents per cell. These inhibitors had different growth-inhibitory and lethal effects on cells depending on culture condition, concentration of inhibitor, etc., suggesting that there is a wide variety of mechanisms of inhibition. In the presence of Cu++ and Zn++, the cells died in the logarithmic growth phase only, and not in the stationary phase. Therefore, it appears that death of cells was mainly caused by the repression of synthesis of essential materials. On the other hand, the time course of decrease in viability in the logarithmic growth phase was similar to that in the stationary phase when ethanol or phenol was added to the culture. Therefore, the death of cells was suggested to be attributable not only to repressed synthesis of essential materials but also to decomposition or inactivation of essential materials. In the presence of ethanol, decomposition of cellular RNA accursed almost in parallel with the loss of viability. This situation was similar to the previously reported relationship between viability and RNA content in a longstanding stationary phase culture.View full abstractDownload PDF (1203K) -
Toshimasa Hirama, Tomio Adachi, Hiroshi Yamaguchi, Kenji Yamaguchi, Sh ...1980 Volume 6 Issue 1 Pages 87-111
Published: January 10, 1980
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSDownload PDF (3629K)
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