KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 21 , Issue 1
Showing 1-35 articles out of 35 articles from the selected issue
  • Takuo Shigehisa, Osamu Okuma, Toshio Ohzawa, Tetsuo Matsumura
    1995 Volume 21 Issue 1 Pages 1-7
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Victorian brown coal from Australia is not familiar to industry, except for local power generation, due to its.high moisture content (ca. 65wt%). The BCL project, which is based on direct coal liquefaction, has developed a slurry dewatering process aimed at drastic energy saving.
    A 2t/d pilot plant was constructed at Morwell in Australia in 1989 and success-fully operated in order to develop this process. The operation results showed high dewatering and heat efficiency and proved that slurry-dewatering is a good pretreatment for brown coal liquefaction.
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  • Nobuyoshi Hashimoto, Nobuhiro Fukuda, Kazushi Ohshima, Mitsuro Matsuna ...
    1995 Volume 21 Issue 1 Pages 8-14
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Pre-commercial scale tests with a small agitated reactor and a large one were carried out to obatain needle-like α-FeOOH fine particles using a batch-wise operation.
    Both agitated reactors were chosen in attempts to produce needle-like α-FeOOH fine particles of 70110m2/g specific surface area (Se) and of coefficient of variation (σl/la) sharper than 0.50 for distribution of particle length along the major axis (l).
    To regulate the required specific surface area and the uniformity of particle size distribution, an intermittent and rapid oxidation program was devised for both agitated reactors. The program consists of 7 to 21 blowing cycles with 30-minute intervals?
    The time of blowing pulse per cycle was set at 2 or 5 minutes for oxidation and the remaining time (28 or 25 min), in the absence of air blowing, was allocated for maturing of the produced particles.
    The following items were also studied;
    a) shape change of the conversion function in the case of intemittent and rapid oxidation, b) relationship between Se and oxidation time (θr), c) relationship between arithmetic mean length of the particles on the major axis (la) and Se, and d) relationship between σl/la and Se.
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  • Kazuo Tsutsumi, Isao Hashimoto, Shozo Kanamori, Mikio Murao, Noboru Ic ...
    1995 Volume 21 Issue 1 Pages 15-21
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Many layouts have been used for limestone calcining, such as preheating of limestone and combustion air, precalcination of limestone and heat recovery from combustion gas and quicklime produced. To obtain an optimum system, we focused on fuel consumption, calcination efficiency and prevention of coating trouble in a preliminary study, resulting in a system consisting of precalcination of limestone using a fluidized bed and subsequent fluidized-bed calciner.
    A commercial-scale plant with capacity of 50t/d for CaO was designed and constructed. Both the degree of pulverizing and entrainment depends on properties of the raw material limestone. Therefore, by controlling the ratio of fuel consumption between the freeboard and fluidized bed, both conversion over 96% and calcination efficiency over 98% were successfully achieved.
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  • Yozo Takemura, Tatsuo Mukai, Kengo Senoo, Motoyuki Suzuki
    1995 Volume 21 Issue 1 Pages 22-31
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Decomposition of tetrachloroethylene in the aqueous phase was studied by applying porous reticulated iron (specific surface area 0.32 m2/g; porosity rate 89%; bulk density 0.8) as the reducing agent. The following results were obtained.
    1) The reduction reaction of tetrachloroethylene aby using reticulated iron is a first order reaction and the reaction stoichiometry is as follow;
    Fe+1/4C2Cl4+1/4O2+5/2H2O→Fe (OH) 3+1/4C2H4+HCl
    2) Reticulated iron is effective in decomposing tetrachloroethylene by using of its large specific surface area.
    3) The degree of decomposition of tetrachloroethylene is determined by the amount of iron ion dissolved into aqueous phase from the reticulated iron and the following relationship was obtained.
    K=0.002W
    W (g dm-3) is the amount of reticulated iron used in the experiments and K (mg/dm3·h) is apparent decomposition rate constant.
    4) During the process of decomposition or tetrachloroethylene, a slow stagnation of decomposition occured. This slow stagnation is caused by accumulation of ironoxy-hydrooxide and is easily avoided by adding CaCl2.
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  • Yozo Takemura, Tatsuo Mukai, Kengo Senoo, Motoyuki Suzuki
    1995 Volume 21 Issue 1 Pages 32-40
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Decomposition of tetrachloroethylene (TCE) in the aqueous phase was studied by applying an oxidative reaction (Fenton's reaction) on porous reticulated iron using a closed vessel and the following results were obtained.
    (1) Reticulated iron is effective in applying Fenton's reaction for decomposing TCE TCE is decomposed to CO2 in about 30 minutes stirring by use of 5060g/dm3 of reticulated iron and a 510 molar ratio of H2O2/PCE.
    (2) The decomposition reaction rate of TCE is maximum in the range of 510 mole ratio of H2O2/PCE and the following relationship was obtained where W (g/ dm3) is the amount of reticulated iron used in the experiments and K (mg/dm3.h) is apparent decomposition rate constant.
    K=0.102W
    In the range above a 10 molar ratio of H2O2/PCE, the decomposition rate of TCE decreases because the surface of the reticulated iron becomes inactive.
    (3) The decomposition reaction formulae of TCE are shown as follows;
    In the range of pH >4.0
    2Fe+C2Cl4+5H2O2→2CO2+2Fe (OH) 3+4HCl
    In the range of pH < 4.0
    2Fe+C2Cl4+5H2O2→2CO2+2/3Fe (OH) 3+4/3FeCl3+4H2O
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  • Noboru Kamei, Setsuro Hiraoka, Yoshihiro Kato, Yutaka Tada, Hirotaka S ...
    1995 Volume 21 Issue 1 Pages 41-48
    Published: January 15, 1995
    Released: November 12, 2009
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    Power consumption for paddle impellers in both spherical and cylindrical agitated vessels was measured over a wide range of Reynolds number from laminar to turbulent flow regions. By using the friction factor f and the modified Reynolds number ReG, which were defined by Hiraoka and Ito, a power correlation was expressed as
    f=CL/ReG+Ct {(C/ReG+ReG) -1+ (f/Ct) 1/m} m
    where CL, Ct, C, f and m were empirically correlated with impeller size and the number of impeller blades. The power correlation was applicable to both spherical and cylindrical vessels, when the apparent diameter of the spherical vessel was equal to the diameter of the cylindrical vessel which had a height equal to its diameter and had the same volume as the spherical vessel. The power consumption was well correlated with the experimental results of Nagata, et al. and Hixson-Baum. The critical Reynolds number, which was used for a simple estimation of power number in fully baffled conditions Np, max by Nagata, was directly related to the coefficient C characterizing transition from a laminar to a turbulent flow region in the correlation proposed here.
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  • Takaaki Mizutani, Moriyoshi Tamura, Yasuhisa Nakamura, Hitoki Matsuda, ...
    1995 Volume 21 Issue 1 Pages 49-55
    Published: January 15, 1995
    Released: November 12, 2009
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    With a view to improving the performance of a radiant tube burner used as a heating source in industrial furnace, a new combustion technique is proposed in the present study. The technique allows heat-resistent particles to circulate within the burner. The fundamental combustion characteristics of this new combustion technique and the effect of the amount of circulating particles on burner performance are studied using a trial gas burner. Stable combustion of methane gas is confirmed in the stable region of solid circulation, resulting in an increase in heating efficiency and in an improvement in the temperature uniformity of the radiant tube surface. The relation between burner performance and amount of circulating particles is also confirmed in this study.
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  • Mitsuhiro Ito, Hiroyuki Ninomiya, Satoru Fujii
    1995 Volume 21 Issue 1 Pages 56-65
    Published: January 15, 1995
    Released: November 12, 2009
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    Experimental and numerical studies were conducted on the classification characteristics of cage-type centrifugal powder classifiers by using three indexes : split ratio β to the coarser side of classified products; classification accuracy indexes κ1 (=d25/d75); and κ2 (=d50/d75).
    β was expressed by an equation containing two parameters; β0 and γ, where, β0 relates to the aggregation index defined in this study, and γ relates to both the dissi-pation energy in a classifier and the 50% cut-size.
    The index κ1 becomes smaller with decreasing dispersion efficiency in the classifier and the 50% cut-size.
    As the rotational speed of the rotor should be increased in order to reduce the cut-size, air velocity passing through the adjacent rotor-blades would become uneven with a reflux of the air. As a result, large particles will mix into the finner powder, ie. κ2 will decrease. This phenomenon is suppressed by increasing the number of rotor-blades.
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  • Kohnosuke Matsushita, Nobuhiko Kanekuni, Hisashi Nogaki, Ikuo Itakura, ...
    1995 Volume 21 Issue 1 Pages 66-73
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Soy sauce sediment is formed in pasteurization of raw soy sauce. It is treated as industrial waste, though its main component is soy sauce, because of difficulty in perfect clarification of the suspension. In this paper, we decided a suitable range of pore size of microfiltration and a cut-off level of ultrafiltration to clarify soy sauce sediment and we developed a rotating disk membrane module (RD Module) and compared performance with conventional a multi-tubular membrane module (MT Module).
    The optimum range to obtain soy sauce of quality was less than a pore size of 0.2μm for microfiltration, while ultrafiltration was not suitable for soy sauce sediment. Ultrafiltration was restricted by rejection of colors and nucleic acids and related compounds in soy sauce sediment, rather than rejection of bacteria and ethanol.
    An RD Module could recover soy sauce of quality and was superior to an MT Module for concentration ratio, but the permeate fluxes of the RD Module decreased under conditions of high revolution as centrifugal forces were exerted on the permeate in the disk membrane.
    The power consumption of the RD Module was proportional to the cube of number of revolutions and to the fifth power of the radius, so it was found that one of methods for the scale up is to increase the number of disk membranes than increase the radius.
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  • Hideo Hosoda, Toshimasa Hirama, Hidetoshi Aoki
    1995 Volume 21 Issue 1 Pages 74-82
    Published: January 15, 1995
    Released: November 12, 2009
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    Some techniques for simultaneous reduction of nitrous and nitrogen oxide emissions in bubbling fluidized-bed combustion were systematically examined and evaluated with an experimental combustor having an inner diameter of 0.16 m. Several kinds of fine solid particles, such as red mud, calcium and magnesium oxides, were fed into the fluidized bed with coal and injected into the flue gas duct. No satisfactory effect on nitrous oxide decomposition was found from the above experiments. Although propane gas injection with premixed air into the top of the free-board decreased nitous oxide substantially, nitrogen oxides emission increased remarkably. Two-stage combustion was rather effective for simultaneous reduction of nitrous and nitrogen oxides. An Improved Three-Stage Combustion System (ITS) in which propane gas with substoichiometric air was injected from the secondary-air injection port was examined to reinforce the effectiveness of two-stage combustion. Excellent performance in the system, more than 85% of reduction ratio for nitrous oxide without any increase in nitrogen oxides, was confirmed at a maximum free-board temperature of around 925°C
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  • Kazutoyo Nakaya, Yoshitomo Hanakuma, Takashi Sasaki, Eiji Nakanishi
    1995 Volume 21 Issue 1 Pages 83-88
    Published: January 15, 1995
    Released: November 12, 2009
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    The data reconciliation method was applied to a linear material balance of distillation columns and a nonlinear yield balance of cracking furnace in an ethylene plant. It was very important to check the steady state of the process by run test before executing data reconciliation. The result indicates that the data reconciliation method is sufficient for practical use and problems for arrangements of instrument is closed up.
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  • Yoshitomo Hanakuma, Kazutoyo Nakaya, Takashi Sasaki, Eiji Nakanishi
    1995 Volume 21 Issue 1 Pages 89-94
    Published: January 15, 1995
    Released: November 12, 2009
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    A method of detecting abnormal process signals in fault diagnosis by attractor and multiresolution analysis is developed. It involves the detection of abnormal signals using an attractor vector norm analysis from an attractor of process signals and the detection of abnormal signals using a multiresolution analysis which decomposes process signals by the multi-decimation method. The method proposed in this study has the advantage of detecting online abnormal signals in industrial use. It was applied to abnormal detection of catalyst feed flow in a linear low-density polyethylene plant to confirm the design philosophy. The actual result indicates that the proposed method is effective in detecting abnormal process signals.
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  • Masaki Funakoshi, Toshio Kawamura, Kaoru Nakano, Seiichiro Koda
    1995 Volume 21 Issue 1 Pages 95-101
    Published: January 15, 1995
    Released: November 12, 2009
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    The effect of light irradiation on the catalytic oxidation reactions of olefins by silver catalysts was studied. The silver catalysts used were silver metal powder and supported silver metals on semiconductor anatase titania or several insulator oxides such as γ-alumina, silica and porous vychol glass. Light irradiation increased the reaction rate whenever the catalysts were used. When anatase titania was used as a support, the increase in reaction rate was dependent on the irradiation wavelength, and this increase was caused by some photochemical effects. However, such a wavelength effect was not found for γ-alumina, showing that rate promotion was due to the temperature increase under light irradiation.
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  • Kunihiko Takeda, Masatoshi Tanouchi
    1995 Volume 21 Issue 1 Pages 102-110
    Published: January 15, 1995
    Released: November 12, 2009
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    Theory and experiments on the enrichment factor of a separation unit with the aid of chemical reactions were studied. The separation unit is composed of reactive species (X), unreacted chemical species (A) and reacted chemical species (D). The enrichment factor of the unit depends on the enrichment factor of the chemical reactions and the distribution of the chemical species on the adsorbents and in the solution. In cases where the factor is small, εu=ζ·εs, where ζ is a “localization coefficient” newly difined in this report. The factor εu is smaller than εr because the coefficient (ζ) is less than 1.0 on all occasions. Reductions in enrichment factors due to the coefficient were observed in the experiments of uranium isotopes and carbon isotopes separations. It was also suggested that the enrichment factor in the separation process depends on the kinetic constants as well as distribution.
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  • Michitaka Suzuki, Hideo Iguchi, Akihiro Ohtani, Mitsuaki Hirota, Toshi ...
    1995 Volume 21 Issue 1 Pages 111-117
    Published: January 15, 1995
    Released: November 12, 2009
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    The hydrophobic surface treatment of quartz powder by mechanochemical reaction was investigated using a planetary mill and a ball mill. From comparison of the hydrophobic weight fraction data, it was found that planetary milling reduced the grinding time required to achieve the reaction to about 1/30 to 1/300 of the time for ball milling. So, planetary milling is very effective to reduce the grinding time for mechanochemical reactions, while almost the same energy was necessary to achieve the reaction for both planetary and ball milling. The hydrophobic weight fraction can be estimated from the specific surface area or 50% particle diameter of the ground products.
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  • Masato Tanaka, Hideyo Tanaka, Isao Kimura, Natsukaze Saito, Kazuhiko H ...
    1995 Volume 21 Issue 1 Pages 118-125
    Published: January 15, 1995
    Released: November 12, 2009
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    Suspension polymerization of styrene was performed using calcium tertiary phosphate as the suspension stabilizer and sodium dodecylbenzenesulfonate as the suspension co-stabilizer. It was investigated how the stepwise and continuous reduction in impeller speed over the course of polymerization affected the final particle size distribution.
    Transient mean droplet diameters, final particle size distributions and final mean particle sizes were significantly affected by the degree of impeller speed reduction and the polymerization conversion.
    Three step reduction in the range of conversion from 0 to 0.45 was found to produce polymer particles of the most uniform size.
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  • Seiichi Deguchi, Akira Takahashi, Hitoki Matsuda, Masanobu Hasatani, K ...
    1995 Volume 21 Issue 1 Pages 126-131
    Published: January 15, 1995
    Released: November 12, 2009
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    Double-base and composite solid propellants with contain Al and/or Zr powders were burned in a pressurized burning apparatus and a bomb calorie meter. The components and geometric characteristics of combustion products were investigated by x-ray diffraction (XRD), energy dispersion x-ray (EDX) and scanning electron microscope (SEM). It was recognized that both a variety of solid propellants and the burning pressure had no influence on XRD results of combustion products. A tetragonal ZrO2 was detected from combustion products of solid propellants with Al and Zr powders by XRD. According to the EDX analysis of combustion products and their grinded samples, there was a possibility that the combustion products were gradient materials of Al and Zr compounds. Every combustion product had a spherical shape, irrespectively of both the components of the solid propellant and the burning pressure. The size of the combustion products decreased with increasing burning pressure.
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  • Masaru Yarime, Atsushi Tsutsumi, Akinobu Sasaki, Tawatchai Charinpanit ...
    1995 Volume 21 Issue 1 Pages 132-136
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The behavior of bubbles in a circulating gas-liquid-solid fluidized bed was investigated in a column of 25.4 mm ID and 5 m height with glass beads of 5 different sizes by using a bore scope. The distribution of bubble size followed the logarithmic normal distribution law. At high liquid velocity the effects of particle size and solid concentration on volume-surface mean diameter of bubbles were negligible because of liquid turbulent motion.
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  • Kazumi Satoh, Takashi Menju, Masafumi Mochizuki, Atsushi Shono
    1995 Volume 21 Issue 1 Pages 137-142
    Published: January 15, 1995
    Released: November 12, 2009
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    The mixing times of liquids in gas-liquid contactors were examined under aeration and/or mechanical agitation.
    The mixing times were inversely proportional to the cubic root of power input per unit liquid volume in both limit cases of mechanical agitation and aeration. Mechanical agitation was more effective than aeration for liquid mixing under the same total power input. The mixing times under mechanical agitation with aeration decreased with increasing ratio of power input by mechanical agitation compared to aeration under the same total power input.
    A semiempirical correlation for mixing times was proposed considering both the contributions of mechanical agitation and aeration. The correlation predicted the mixing times within ±25% over a wide range of operating conditions.
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  • Sang-Chul Jung, Nobuyuki Imaishi, Heung-Chul Park
    1995 Volume 21 Issue 1 Pages 143-151
    Published: January 15, 1995
    Released: November 12, 2009
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    ZnO thin films were prepared from zinc acetate using a horizontal tube hot-wall APCVD (Atmospheric Pressure Chemical Vapor Deposition) reactor. Experimental temperature, flow rate and oxygen concentration in the gas phase were in the range of 473773K, 250750 sccm and 050mol%, respectively. The dependency of growth rate, orientation and morphology of the films on growth conditions was studied experimentally. The C-axis orientation is dominant in films grown at all temperatures, but C-axis orientation is thermally unstable when the film is prepared at low temperatures (T≤673K).
    Conformal step coverage on micro-trenches was obtained at low temperatures (T≤673K). This indicates that the surface reaction is slow in the low temperature range. On the other hand, a much poorer step coverage was obtained at 723K, indicating that the surface reaction at this temperature proceeds much faster and probably via some different reaction mechanism from that at the low temperature range. Assuming that the growth rate at lower temperatures is governed by the surface reaction, the surface reaction rate constant was chosen as a fitting parameter in a heat and mass transfer model to quantitatively explain the experimental growth rate distributions. The activation energy was determined to be 63KJ/mol when CVD takes place without oxygen in the gas phase and 23KJ/mol with 50 mol% of oxygen in the gas phase.
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  • Jun Fukai, Hisayuki Orita, Isao Isokawa, Xiaoshan Yu, Osamu Miyatake
    1995 Volume 21 Issue 1 Pages 152-157
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The linear expansion coefficients of two kinds of formed green carbons were measured under constant heating rates of 0.5 to 3 K/min up to 1200 K. Expansion and contraction peaks appearing below 700K were practically independent of the heating rate, while two contraction peaks appearing in the higher temperature range were dependent on the heating rate. The temperatures at which these two contraction peaks appear were found to linearly vary with the logarithm of heating rate. Our theoretical model representing the contraction mechanism of the formed green carbons can qualitatively explain such contraction behavior in the higher temperature range.
    On the basis of these experimental and theoretical results, approximate equations expressing the heating-rate dependence of the expansion/contraction-peak values and of the expansion/contraction-peak temperatures were presented. Comparison of our experimental results with existing previous experimental ones suggests that the equations for the contraction-peak temperatures are valid for other formed green carbons. The equations predict that the contraction-peak temperatures appearing under heating rates of the order of 10-2 K/min in practical processes are about 100 K lower than those under our experimental condition. This finding is important to determine the heating pattern of practical processes.
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  • Tomohiro Kawai, Ryuichi Egashira, Hidenori Itsuki, Junjiro Kawasaki
    1995 Volume 21 Issue 1 Pages 158-165
    Published: January 15, 1995
    Released: November 12, 2009
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    To develop the design procedure for preparative liquid chromatography of macrolide antibiotics, parameters for the adsorption isotherms and for the ralated rate processes were estimated experimentally and the measured and calculated chromatograms were compared.
    Erythromycin and erythromycin ethyl succinate were selected as a representative antibiotic and a model impurity, respectively. Parameters in Langmuir type adsorption isotherms and rate parameters for silica gel-organic solvent systems were obtained from the values of the moments for the single component chromatograms. Parameters for the adsorption isotherms showed that the extent of separation between solutes varied greatly with the kind and composition of the mobile phase. The mass transfer coefficients in the stationary and mobile phases were compared with the previous correlations. Binary chromatograms were calculated numerically with the use of. Markham-Benton type isotherms for the binary solutes and the values of the said parameters. The calculated and measured chromatograms agreed fairly well over all operating conditions.
    In conclusion, it was recommended for the design of preparative liquid chromatography to calculate chromatograms of macrolide antibiotics by use of parameters estimated by the method presented here.
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  • Satoshi Fukada, Kunihiro Inoue, Masabumi Nishikawa
    1995 Volume 21 Issue 1 Pages 166-172
    Published: January 15, 1995
    Released: November 12, 2009
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    Deposition rates and growth rates of frost on cooled surfaces under reduced pressure were obtained by using a freezing apparatus to reproduce natural convection where an upper surface was cooled at constant temperature and water was evaporated from a lower surface. It was designed for a basic study of a cryogenic freezer proposed for a fuel clean-up system of a fusion reactor. The experiment was carried out in the ranges of 6 ×102 Pa to 1 × 105 Pa of total pressure and 77 K to 261 K of the cooling temperature. Sh numbers at the initial stage of frosting could be fitted to values evaluated using a conventional correlation of natural convection multiplied by a factor based on the critical supersaturation model. Frost thickness and average frost density under reduced pressure grew with the square root of time. In addition, frost thickness increased with [(Ts1-Tw1) t] 0.5 over all the ranges of the experimental conditions except where frost melted on the interface. The difference in frost thickness with the total pressure was qualitatively correlated by a parameter which was defined by the ratio of latent heat flux to sensitive heat flux.
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  • Tohru Niida, Shinichi Ohtsuka
    1995 Volume 21 Issue 1 Pages 173-180
    Published: January 15, 1995
    Released: November 12, 2009
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    Settling velocities of regular shaped agglomerates were measured in a cylindrical container filled with viscous silicone oil. The wall effect was corrected by introducing a linear function of the diameter ratio of particle and container. Model agglomerates were made of a central sphere and 1 to 14 peripheral spheres placed at apexes of the polyhedron or other positions on the surface of the central sphere. Dynamic shape factors were correlated to the coverage of the central sphere, the diameter ratio of the peripheral to central spheres, the number of peripheral spheres on the central one, and the space-averaged projection area of the agglomerate. The dynamic shape factor was found to be correlated most widely with coverage for various types of agglomerates within an error of about 4%.
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  • Ryoichi Kuboi, Akihiro Wakayama, Koji Yano, Isao Komasawa
    1995 Volume 21 Issue 1 Pages 181-188
    Published: January 15, 1995
    Released: November 12, 2009
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    The surface net hydrohobicities and local hydrophobicities of α-Lactalbumin (α-LA) and β-Lactoglobulin (β-LG), major proteins in cheese whey, were evaluated by examining their partitioning behaviors in aqueous two-phase systems such as polyethylene glycol (PEG) /dextran (Dex), PEG/Dex spiked with a non-ionic surfactant, Triton, and Triton/salt two-phase systems.
    Based on the resulting surface properties for both holo- (Ca2+ bound) and apostates (Ca2+ removed), two effective separation systems were presented. The first utilized the difference in surface net hydrophobicity in the holo-state, where comparatively hydrophobic α-LA could be separated in the top PEG rich phase while β-LG could be concentrated in the bottom phase. The second utilized the difference in local hydrophobicity in the apo-state, where Ca2+ was removed by addition of EDTA. In this case α-LA could be partitioned to the top phase containing Triton to which a-LA in the apo-state strongly bound. α-LA, partitioned to the top PEG phase in both systems, could be back-extracted and recovered in the bottom salt phase of the PEG/salt system in more than 90% purity.
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  • Kohei Ogawa, Chiaki Kuroda, Shiro Yoshikawa, Akira Umemoto
    1995 Volume 21 Issue 1 Pages 189-195
    Published: January 15, 1995
    Released: November 12, 2009
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    Flow curves of solid particle suspensions were measured by a new type of viscometer with vacuum glass suction tube and needle, which was developed for the purpose of medical engineering. Experimental data were investigated from the view point of relationship between solid particle concentration and viscosity.
    A new equation to express the relationship was presented by making use of a hydraulic radius concept which has been used for fluid flow in solid particle beds. The new equation could fit the experimental data obtained very well, whether the suspension was Newtonian or a Bingham fluid.
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  • Keiji Furumoto, Tetsuya Imura, Katsumi Nakao
    1995 Volume 21 Issue 1 Pages 196-203
    Published: January 15, 1995
    Released: November 12, 2009
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    The critical superficial gas velocity for suspending solid particles, UG.C is one of the key design parameters to contact the gas, liquid and solid phases in a bubble column. Values of UG.C were measured over a wide range of variables, such as dimension of bubble column, geometry of gas sparger, physical properties of gas and liquid and solid particles.
    The values of UG.C obtained were correlated in terms of a factor of K defined as the ratio of the values of UG.C in a bubble column to that in an airlift bubble column with external liquid circulation having both the same riser (also downcomer) diameter DT and the same static slurry height Ls above gas distributor as in the bubble column concerned. According to dimensional analysis, K was correlated by Ls/DT, the Reynolds number based on the terminal velocity of a single particle Ut, Re (=DT UtρLL) and the ratio of solid particle to liquid densities, ρpL, indicating degree of developing liquid circulation flow over column height, of accompanying solid particles with liquid flow and of suspending solid particles due to buoyancy, respectively. A critical Reynolds number at which the dependence of K on Re changed was found to be 800 for all four spargers used. The two bubble columns with parforated plates as gas spargers showed an identical dependence of K on Ls/DT, Re and ρpL, while the other two columns with single nozzles showed a similar identical dependence. The calculated values of UG.C from the correlation agreed with the observed ones including the literature data within an accurcy of approximately ± 30%.
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  • Toshitaka Funazukuri, Noriaki Wakao
    1995 Volume 21 Issue 1 Pages 204-211
    Published: January 15, 1995
    Released: November 12, 2009
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    The rough hard sphere model was applied to binary diffusion coefficients D12 of organic compounds in dense CO2 at infinite dilution. The following correlation was obtained with selected literature D12 data :
    (AC) B=1.86γ0.38vw (AC) s (υ/υ0) -0.447
    where (AC) B and (AC) s are the products of translational-rotational coupling parameter and correction to Enskog diffusion coefficient for binary diffusion and self diffusion, respectively, γvw is van der Waals diameter ratio for solute to solvent, v is CO2 molar volume and υ0 is close-packed hard sphere volume of CO2. A rough hard sphere model with the above relationship gives selected D12 data (488 data points) with average absolute deviation of 6.2%.
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  • Ryoichi Nagata, Shinichiro Gondo, Mitsuyasu Kawakami, Masami Shiozawa
    1995 Volume 21 Issue 1 Pages 212-218
    Published: January 15, 1995
    Released: November 12, 2009
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    Uricase and catalase were immobilized on oxirane acrylic particle and packed into two separate columns which were connected in tandem. Each sample solution of uric acid, of concentration C and volume G, was injected into an inlet flow of 50 mM tris-borate buffer solution at pH 8.5 and 20°C flowing at the rate υ and the outlet flow was analyzed for its dissolved oxygen concentration by a dissolved oxygen sensor. Sensor output was integrated with respect to time to obrain S. Experimental results were as follows : 1) for the range of υ=7.6 to 15.3 cm3/min, C= 0.10 to 0.50 mg/cm3 and G=0.05 to 0.5 cm3, the relation S=151GC/υ, derived based on the stoichiometric relations, was found to hold, 2) an injection rate of sample solution higher than a certain value gave a value of S lower than the one expected, 3) activity of the uricase column was maintained stably for a period of 150 days, and 4) stochiometric correlation was observed between S and GC/υ for the two-column system. However, the proportionality between these two terms was also observed even in the case of absence of catalase column.
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  • Akihiro Sakoguchi, Ryuichi Ueoka, Yasuo Kato, Yasuhiko Arai
    1995 Volume 21 Issue 1 Pages 219-223
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The vapor pressures of four dimethylpyridines, two trimethylpyridines and three pyrazines were measured by means of a flow apparatus in the temperature Table 10 Parameters of AMP equation ranges, 287422 K, 287427 K and 287411 K, respectively. The observed vapor pressures of 3, 4-dimethylpyridine in the low temperature range, 2, 3, 5-trimethylpyridine and three pyrazines were not available previously. The accuracy of each measurement in this work is estimated to be ± 1 %. The data could be correlated within less than 1 % of the absolute average deviation with the Abrams-Massaldi-Prausnitz (AMP) equation.
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  • Takahiro Horiuchi, Yasuo Kousaka, Yoshiyuki Endo
    1995 Volume 21 Issue 1 Pages 224-227
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Dispersion of PSL coagulated particles consisting of different sized spheres (1.1 and 1.9μm in diameter) in an accelerating liquid flow field in a convergent nozzle was observed. The experimental results show that the dispersability DS, which is defined as the ratio of separation force Fd to adhesion force Fa between particles and is theoretically obtained, can be a useful measure for the dispersion of coagulated particles in an accelerating flow field.
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  • Yuichi Ohira, Masaaki Hoshiba, Eiji Obata, Koji Ando
    1995 Volume 21 Issue 1 Pages 227-230
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    During the long term cultivation, it is known that linear algae grow in or aritificial Spirulina culture. Numerous experiments were carried out to investigate a method of removing linear algae from the Spirulina culture. It was found that linear algae in the Spirulina culture could be removed when inoculated Spirulina were inthe stationary phase or in the later period of linear growth phase if CaCl2 concentration in themedium was reduced by one third from that of a normal medium.
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  • Kiyoshi Matsuyama, Kenji Mishima, Hideyuki Eya, Masatoshi Sakemi, Masa ...
    1995 Volume 21 Issue 1 Pages 230-233
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The activities of methanol, ethanol or water in potassium acetate solutions and the vapor-liquid equilibrium relations of methanol-ethanol-potassium acetate and ethanol-water-potassium acetate systems were determined by use of a flow-type apparatus at 298.15 K. The activity data are presented for single solvent and vapor-liquid equilibrium data are shown for mixed solvents. Salting-out and salting-in effects of potassium acetate were shown for ethanol-water and methanol-ethanol systems, respectively. Further, the experimental data were correlated by using the model of Chen et al.
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  • Kenji Mishima, Shigeyuki Nagayasu, Michinori Totoki, Seishi Morii, Kiy ...
    1995 Volume 21 Issue 1 Pages 234-236
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The partition coefficients of eight kinds of benzene derivatives, which are well-known toxic compounds, were measured in the aqueous two-phase systems containing polyethylene glycol (Mw =7, 500) and dipotassium hydrogenphosphate at 298.15 K.
    Results of correlation of bioconcentration factors with the partition coefficients measured in the aqueous two-phase system were compared with those obtained from the literature data which were determined in the octanol-water partition system for the benzene derivatives. It was found that the partition coefficients of benzene derivatives measured in the aqueous two-phase system could give a better correlation with the bioconcentration factors.
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  • Setsuji Tone, Masahito Taya, Teruyuki Masawaki, Yoshio Iwasaki
    1995 Volume 21 Issue 1 Pages 237-240
    Published: January 15, 1995
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Pervaporation of a butanol-acetone-oleyl alcohol mixture through a poly (dimethylsiloxane) hollow-fiber membrane was conducted to examine the effect of acetone on butanol separation from the mixture. The fluxes of butanol and acetone increased linearly with increasing concentrations of butanol (0-366mol/m3) and acetone (0-49mol/m3) in the feed solutions, respectively. By analyzing these fluxes based on a solution-diffusion model, the permeabilities of butanol and acetone were estimated as 1.6×10-9m2/h and 2.1 × 10-8m2/h, respectively. It was found that the separation factor of butanol ranged from 5 to 17, irrespective of acetone concentration, and that the separation factor of acetone ranged from 53 to 121, independent of butanol concentration.
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