JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 18 , Issue 2
Showing 1-18 articles out of 18 articles from the selected issue
  • YASUO HATATE, DESMOND F. KING, MITSUNOBU MIGITA, ATSUSHI IKARI
    1985 Volume 18 Issue 2 Pages 99-104
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    A semicylindrical fluidized bed of 15 cm diameter with a transparent flat wall was employed to observe bubbles visually. The bed was operated in a range of (UG-Umf) from 8 to 35cm/s, showing the bubbling and slugging regimes. No effect of particle size on bubble size was observed for different sands of 75 to 521 μm in average diameter, where the different sands were compared at the same (UG-Umf) value. The expressions for bubble growth in bubbling three-dimensional beds by Darton et al. and by Mori and Wen were found to be applicable to the semi-cylindrical fluidized bed operating in these regimes. The absolute bubble rise velocity under the present conditions was found to be well represented by the expression of Allahwala et al. developed for three-dimensional beds.
    Download PDF (424K)
  • ISAO MATSUI, DAIZO KUNII, TAKEHIKO FURUSAWA
    1985 Volume 18 Issue 2 Pages 105-113
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Gasification of coal-derived char by steam was carried out in a fluidized-bed reactor with a continuous feed and discharge of solids over a temperature range of 1096 to 1311K at atmospheric pressure. Calculation based on the bubbling bed model and kinetic information obtained by thermogravimetric analysis explained the experimentally obtained conversions of both outgoing steam and char.
    Download PDF (694K)
  • TAKAMI KAI, SHINTARO FURUSAKI
    1985 Volume 18 Issue 2 Pages 113-118
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Pressure fluctuations and bubble frequency in fluidized beds were measured at several stages of temperature ranging from 280 K to 640 K. Four types of powders belonging to group A of Geldart''s classification were used. The quality of fluidization at various temperatures was evaluated by a uniformity index based on pressure fluctuations and by bubble size obtained from bubble frequency. The reduction both in the deviation of amplitude of pressure fluctuations and in bubble size showed that the quality of fluidization improved with increasing temperature. However, at room temperature, beds of dry particles were affected by electrostatic phenomena and thus the fluidity was decreased. The influence of the electrification decreased at elevated temperature, or at room temperature when the particles held water in the pores.
    Download PDF (444K)
  • YOSHINORI ITAYA, NORIO ARAI, MASANOBU HASATANI
    1985 Volume 18 Issue 2 Pages 119-124
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    As one of the basic steps of the R & D regarding a "volume heat-trap" solar collector, a general theoretical model was developed on unsteady heat transfer in a fine-particle semitransparent liquid suspension (FPSS) heated by collimated radiation, taking isotropic scattering in the FPSS layer into consideration. The effect of scattering on heat transfer characteristics in the layer was studied by comparing experimental data with calculated results based on the present model.
    From the results theoretically calculated with the albedo, ω0, as a parameter, it was observed that increase in ω0 reduces the heat-trap efficiency of the "volume heat-trap" solar collector. However, in the region of ω0 <0.1, the effect of scattering on heat transfer was seen to be negligibly small, and this small effect was demonstrated experimentally in a diethylphthalate-graphite particle suspension. Since the region of ω0 <0.1 covers that of the practical design conditions of the solar collector entirely, a simpler theoretical model that ignores the effect of scattering has enough validity from the viewpoint of practical use.
    Download PDF (458K)
  • SHIGEO ISHII, MASAHITO TAYA, TAKESHI KOBAYASHI
    1985 Volume 18 Issue 2 Pages 125-130
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    An extractive fermentation system was developed to prevent end-product inhibition of Clostridium acetobutylicum I AM 19012, which mainly produces butanol and acetone. Butanol exhibited greater toxicity to the microorganism than acetone, and its growth was completely inhibited above 10kg/m3 of butanol. As an extracting solvent suitable for acetone-butanol fermentation, oleyl alcohol (cis-9-octadecen-l-ol) and C-20 guerbet alcohol (branched-chain alcohol of carbon number, 20) were selected from among 29 organic compounds, based on their nontoxicity to the microorganism. These two solvents had high partition coefficients for butanol, and could be reused without deterioration. In fermentation with the solvent (solvent phase: aqueous phase = 2:5 (v/v)), the viability of the microorganism was resumed by the liquid-liquid extraction of butanol from the broth, and the amount of butanol produced was 2.6 times that in fermentation without extraction.
    Download PDF (508K)
  • SETSUJI TONE, SHOICHI KIMURA, YOICHI HINO, TSUTAO OTAKE
    1985 Volume 18 Issue 2 Pages 131-136
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Activated carbon produced from lignite char was impregnated with potassium carbonate and gasified with steam in an H2O-H2-CO mixture gas at total pressure of 1.5 MPa and in the range of temperatures from 973 to 1073 K.
    The gasification rate changed with the progress of carbon conversion and showed a maximum value at a carbon conversion around 0.3-0.4. The ratio of the gasification rate at any conversion to the initial rate could be correlated with the extent of carbon conversion by a relation which took into account the structural change of pores constructed in char filled with catalyst. The initial rate of gasification could be represented by a Langmuir-Hinshelwood type equation of single site mechanism including adsorption terms of H2O and H2. The rate constant was found to be roughly proportional to the atomic ratio of potassium to carbon. The apparent activation energy was 97.8kJ/mol, independently of the potassium content and carbon conversion.
    Download PDF (509K)
  • ISAMI YOSHIFUKU
    1985 Volume 18 Issue 2 Pages 137-141
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    A new approach, called sequential cell How graph representation, to the packed tower process problem is studied, taking aim at freedom from the troublesome graphical routine. An algorithm for the construction of such flowgraphs is proposed and applied to a cooling tower process problem.
    The resulted sequential cell flowgraph shows that the problem treated is a single-variable searching problem with three tearing variables. Computer programming according to this representation will permit rapid solution for the tower height and the behavior of state variables through the tower.
    Download PDF (351K)
  • KEE KAB KOO, YEONG MIN JEON, WON KOOK LEE
    1985 Volume 18 Issue 2 Pages 142-147
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The mass transfer rate during drop formation was measured by an experimental method in which a continuousphase adder was used. The continuous phase was circulated in the column counter-currently to the drop phase, and the distance between the nozzle tip and the drop collector was kept short.
    From the data obtained in four binary systems a best drop size prediction model was chosen, and the model was applied to four ternary systems for obtaining interfacial tension during mass transfer. The drop size was correlated in terms of solute molar flux, nozzle size, and density difference between the dispersed and continuous phases. Also, the interfacial tension change was correlated with solute molar flux. The two correlation equations gave good predictability for the systems in this study.
    Download PDF (390K)
  • MASAO SUDOH, HIROSHI KAMEI, KOZO KOIDE
    1985 Volume 18 Issue 2 Pages 148-153
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    A novel electrochemical reactor having a vertical stack of perforated graphite plates as bipolar electrodes was investigated by using the electrolysis of sodium bromide. The ratio of Faradaic current to reactor current was explained by an equivalent circuit model which consisted of bypass, sandwiched solution and Faradaic resistances.
    Energy consumption for bromine production was influenced by liquid flow regime such as continuous flow or trickle flow and by introducing inert gas countercurrently. Effects of flow regimes of liquid and gas on energy consumption were clarified by the changes of Faradaic current efficiency and the ratio of Faradaic current to total reactor current with the electrode potential difference between the two sides of a bipolar plate.
    Download PDF (445K)
  • YASUO KATO, TOKIHIRO KAGO, SHIGEHARU MOROOKA, AKIO NISHIWAKI
    1985 Volume 18 Issue 2 Pages 154-159
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The longitudinal dispersion coefficient of droplet phase was measured in 6.6 and 12.2 cm i.d. single- and multistage bubble columns where kerosene was dispersed by air and water flows.
    Experimental residence time distribution curves of the droplet phase were analyzed by a newly proposed dispersion model, which included the back-flow of droplets through perforated baffle plates and the exchange of dye concentration in the droplet phase at the perforated baffle plates due to dispersion-coalescence phenomena. The exchange coefficient of the dye concentration was obtained by comparing experimental residence time distribution curves with the theoretical ones. The overall longitudinal dispersion coefficient of the droplet phase in multi-stage bubble columns was satisfactorily simulated by the present model, parameters of which were all given as experimental equations.
    The mean gas holdup in the 12.2cm i.d. column for air-water-solvent (n-hexane, terpentine oil and a mixed oil) systems was increased about 20% by installation of perforated baffl plates.
    Download PDF (434K)
  • KOJI TAKAHASHI, YASUYUKI TAKAHATA, TOSHIYUKI YOKOTA, HIROTAKA KONNO
    1985 Volume 18 Issue 2 Pages 159-162
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    In a helical ribbon agitator, mixing patterns and mixing times for two miscible, highly viscous Newtonian liquids with different viscosities are investigated. From the observed mixing patterns, empirical correlations for mixing time are obtained as functions of the Reynolds number and a dimensionless number defined by the ratio of gravitational to viscous force. The optimum operational conditions for the mixing process are predicted from these correlations.
    Download PDF (473K)
  • KAZUHARU YOSHIZUKA, KAZUO KONDO, FUMIYUKI NAKASHIO
    1985 Volume 18 Issue 2 Pages 163-168
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    A kinetic study of copper extraction with reagent-grade N-8-quinolyl-p-dodecylbenzenesulfonamide was carried out by using a stirred transfer cell, along with studies of the distribution and interfacial equilibria of the extractant between the organic and aqueous solutions at 303K.
    The rate of copper extraction was analyzed by a model of the interfacial reaction between the adsorbed extractant (HR) and the adsorbed copper complex (CuR+) accompanied by the mass transfer steps of each species. The experimental results show good agreement with the results calculated by use of this interfacial reaction model, concerning the initial extraction rate and the extent of copper extraction over a wide range of experimental conditions.
    Download PDF (470K)
  • RYUICHI KAJI, YUKIO HISHINUMA, HIROSHI KURODA
    1985 Volume 18 Issue 2 Pages 169-172
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Download PDF (285K)
  • AKIRA OHKAWA, YOSHIHIRO SHIOKAWA, NOBUYUKI SAKAI, KAZUO ENDOH
    1985 Volume 18 Issue 2 Pages 172-174
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Download PDF (237K)
  • KAKUJI TOJO, KIRTI H. VALIA, YIE W. CHIEN
    1985 Volume 18 Issue 2 Pages 174-178
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Download PDF (369K)
  • HIROSHI IKEDA, YASUSHI TAKEUCHI
    1985 Volume 18 Issue 2 Pages 178-181
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Download PDF (253K)
  • KENJI KUBO, HARUO HIKITA
    1985 Volume 18 Issue 2 Pages 181-184
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Download PDF (290K)
  • HIRONOBU IMAKOMA, MORIO OKAZAKI, RYOZO TOEI
    1985 Volume 18 Issue 2 Pages 184-187
    Published: April 20, 1985
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Download PDF (263K)
feedback
Top