KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 14 , Issue 6
Showing 1-18 articles out of 18 articles from the selected issue
  • Masakazu Yamazaki, Masaaki Ohya, Kentaro Tsuchiya
    1988 Volume 14 Issue 6 Pages 713-720
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A real-time flame diagnostic technique that can detect, without probing, the air equivalence ratio of individual burners in industrial furnaces is needed. To explore an optical approach for this purpose, characteristics of the flame emission spectrum in the near ultraviolet and visible region were studied in a turbulent jet diffusion flame and a practical diffusion-type gas burner.
    Net spectrum intensities of OH and CH isolated from continuous spectra of thermal radiation due to soot particles were shown to be an effective index for flame diagnostics because they represent the local burning rate qualitatively. Spectrum intensities of OH and CH detected at the near burner port region were found to be linearly dependent on both the operating air equivalence ratio and the fuel flow rate. From these results, an optical technique of detecting the air equivalence ratio of the burner by flame emission spectrum is presented.
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  • Kazuyuki Ito, Toshio Sawa, Harumi Matsuzaki, Katsumi Osumi
    1988 Volume 14 Issue 6 Pages 721-727
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The effect of deposited small particles on the removal characteristics of suspended corrosion products in sulfonic and carboxylic acid cation exchange resins and styrene divinyl benzene beads (S.D.B.) was studied. The surface conductivity of the resin beads was determined by measuring the impedance response with frequency for a mixture of resin beads and suspended particles.
    The removal performance of the resin beads at a feed linear velocity of 2.8 cm/s was in the order : sulfonic acid resins<S.D.B.<carboxylic acid resins. The removal performance of cation exchage resins depended on the kinds of ions released from rasins while their counter ions were exchanged. The surface conductivity of the resin beads was in the order : sulfonic acid resins>carboxylic acid resins>S.D.B.
    The variations in removal characteristics in the different kind of resin beads were explained by (i) charge repellence due to deposited particles, and (ii) a decline in the effect of surface charge due to the surface conductivity of resin beads.
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  • Kyu Suk Hwang, Shigeyuki Tomita, Eiji O'shima
    1988 Volume 14 Issue 6 Pages 728-738
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Two basic concepts, SCOPE and SCRIP, were introduced for synthesizing the operating procedures of a chemical plant. A new methodology that mimics the behavior of human operators was developed, along with a computer-based system that evaluates the effectiveness of the methodology.
    A plant can be seen as a hierarchical set of subsystems, each of which has particular subfunction that is required for achieving its upper-level function. The upperlevel function can be achieved by realizing all the subfunctions that are subordinate to the upper-level function. Each subsystem is called a SCOPE. The state of the plant at each operation step and the behavior of each subsystem were managed by the SCOPEs.
    On the other hand, the heuristic knowledge and operational routine works were generalized by use of the new concept SCRIPT, and were organized in hierarchical form. Two khowledge bases of SCOPEs and SCRIPTs were developed by using the socalled object-oriented approach. SCRIPTs were used as a guideline for synthesizing operating procedures for starting up the plant.
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  • Masayuki Horio, Mamoru Ishida, Maki Takada, Norichika Tanaka
    1988 Volume 14 Issue 6 Pages 739-747
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    To establish a rational scale-up method for fluidized beds the mixing characteristics of fluidized solids and those of floating bodies in the bed are examined experimentally. For experiments in mixing of bed particles magnetically separable tracer particles were developed. Floating bodies were simulated by polypropylene tablets. For four geometrically similar equipment units of 50, 150, 300 and 600mm inside diameters, the sizes of bed particles and floating bodies and the gas velocity were adjusted so that the scaling law of Horio et al. (AIChE J., 32, 1466 (1986)) was satisfied. From the measured lateral diffusivity of solids and the segregation pattern of floating bodies it was confirmed that the scaling law of Horio et al. can be extended to the mixing behavior of both the bed particles and the floating bodies. Based on the present data as well as those in the literature the following new correlation for Er, the lateral diffusivity of solids in non-tapered gas-solid fluidized beds was developed :
    (u0-umf) De/Er=1.07 [(u0-umf) umf/gLmf] 0.25 (B/Lmf) 0.75
    where De is the equivalent bed diameter and B is the two-dimensional bed thickness.
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  • Jun Fukai, Yuji Shimizu, Takatoshi Miura, Shigemori Ohtani
    1988 Volume 14 Issue 6 Pages 748-754
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A new unsteady method is proposed to measure simultaneously thermal conductivity and diffusivity, based on the analytical solution for an infinite hollow cylindrical system where a sinusoidal heat flux originates from a wire in the center. The method can also be improved to measure easily the temperature dependencies of the thermal properties under the continuous heating process. Measurement errors due to the finite specimen size and the displacement of measurement position are estimated numerically. It is found that the specimen radius size should be three times the distance between central heat source and measurement position. Displacement of measurement position has little effect on the measured value of thermal conductivity.
    Measurement is carried out for a packed bed of aluminum oxide particles in the temperature range from 350K to 650K at a rate of 3K/min. The measured results agree well with those reported in previous work using the hot-wire method and periodic heating method.
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  • Hirofumi Kikkawa, Hiroshi Takezaki, Yoshinori Ootani, Kazunori Shoji
    1988 Volume 14 Issue 6 Pages 755-761
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Deashing of coal by froth flotation with vaporized collectors is studied in combination with preparation of coal water mixtures (CWM). Comparison of deashing performance and flow property of deashed CWM is made between the present method and conventional froth flotation. The effects of coal cleaning on slurry properties are also investigated. It is found that the amount of collector needed to recover carbonaceous matter can be reduced by vaporization of the collector, giving rise to the lower apparent viscosity of deashed CWM. Slurry viscosities of some coals are decreased by cleaning while those of other coals do not change. No increase of slurry viscosity by coal cleaning was observed. Dispersant requirement can be also reduced for some coals because ash, which prevents coal particles from being dispersed, was reduced. Ash erosion and deposition problems can be reduced by the use of cleaned coals, suggesting the possibility of boiler volume reduction.
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  • Kenji Shimizu, Suisei Yamamoto, Noriaki Kubota
    1988 Volume 14 Issue 6 Pages 762-768
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The number and size of secondary nuclei produced by collision between a glass rod and a seed crystal were measured by changing the collision energy (370, 1110, 1700 and 2230 ergs), the number of repeated collisions (5, 10, 20, 30 and 40) and the time interval between collisions (1, 5, 10, 30 and 60 sec). The number of secondary nuclei per collision did not change with energy but increased linearly with increasing number of repeated collision. When the interval between collisions was shorter than 20 sec, the number of secondary nuclei per collision was 102 in order of magnitude, but when the interval was larger than 30 sec, the number became 103. The last result suggests that time is needed to bring the crystal surface to a condition that generates secondary nuclei easily. The number of secondary nuclei scattered even at a fixed experimental condition. This seems, from microscopic observation of the surface of seed crystals after collision, to be due to differences in characterisics of seed crystal (roughness of surface, fragility). The size of most secondary nuclei ranged from several micrometers to about twenty micrometers.
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  • Hitoki Matsuda, Mitsutoshi Miyazaki, Masanobu Hasatani, Michio Yanador ...
    1988 Volume 14 Issue 6 Pages 769-778
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A high-temperature chemical heat pump was manufactured on laboratory scale by combining a Ca(OH)2/CaO reversible thermochemical reaction with the evaporation /condensation of water in two hermetic cylindrical vessels connected with each other. Both the heat-release and heat-storage characteristics of this apparatus were tested in terms of the temperature response of the solid particle bed in the reactor.
    In the heat-release mode, it was found that no sooner had the steam from the evaporator been introduced into the reactor than the CaO particle bed in the reactor was heated up to a certain constant temperature which corresponds to the temperature at the reaction equilibrium, and that the CaO particle bed remained at this constant temperature for the greater part of the reaction period. Thus the CaO particle bed could be easily heated up above 800 K when pressurized steam higher than 142 kPa in pressure was employed.
    After the heat-release mode, the CaO particle bed could be regenerated by heating the produced Ca(OH)2 particle bed above the temperature at which the equilibrium pressure in the reactor is greater than the water vapor pressure in the condenser. In this heat-storage mode, the Ca(OH)2 particle bed was kept at another constant temperature higher by several tens of degrees, than the reaction equilibrium at the pressure of the condenser, Under the conditions of the present experiment, when the Ca(OH)2 particle bed was kept above 700 K, it was recognized that water at room temperature was sufficient for the regeneration of CaO as a low-temperature heat source.
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  • Fuming Chen, Hiroyuki Tanaka, Yuji Naka, Eiji O'Shima
    1988 Volume 14 Issue 6 Pages 779-785
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    To investigate the association mechanism of tri-n-octylamine (TOA) with organic acids as well as the diluent effect on the association equilibrium of the systems, excess volumes different (υE) of the mixtures of TOA with four lower carboxylic acids and mixtures of TOA and acetic acid with five different diluents were measured at 30°C. For the ternary mixtures, evaluation of the diluent effect was based on an approximation of the pseudo-binary mixture of TOA and acetic acid.
    The findings in the present investigation are as follows.
    1) For the binary and pseudo-binary mixtures, the composition (XBmin), which gives the minimum valume of υE varies according to the kinds of acids and diluents.
    2) The dominant associating species of TOA with an acid can be estimated from the XBmin. And the equilibrium constants of the association are obtainable from the model proposed in this study by fitting the observed υE values of the binary and pseudobinary mixtures.
    3) There is a significant relationship between XBmin and the acceptor number of the diluent. The stronger in acceptor characteristics the diluent is, the smaller the number of the acid associated with TOA becomes.
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  • Meguru Kaminoyama, Fumio Saito, Mitsuo Kamiwano
    1988 Volume 14 Issue 6 Pages 786-793
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A method of numerical analysis of three-dimensional flow behaviour of highly viscous pseudoplastic liquid in a stirred vessel was established. The proposed method is based on the simultaneous relaxation method for velocity and pressure in the frame of the finite difference method (FDM). Numerical analysis of the Newtonian fluid is applied to the non-Newtonian one, in which the viscosity constitutive equation is the three-parameter Ellis model. The developments of the circumferential velocity distributions on the radial axis and of the circulation flow with time are presented in this analysis.
    The reliability of this numerical method was verified by the good agreement of the simulation results with experimental values by means of an image sensor velocimeter.
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  • Yukio Nakanishi, Yuuichi Mizuno, Masao Kobari
    1988 Volume 14 Issue 6 Pages 794-802
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The rate of penetration of ethanol, which is the principle flavoring constituent of tobacco, and a measuring method for that rate were studied in order to clarify the behavior of droplets of flavor in the flavoring process used by the tobacco industry. An equation for the penetration was derived by momentum balance and experimental results were correlated well by this equation. A simple method for measuring the rate of penetration was proposed on the basis of this equation.
    The time required for penetration of a droplet of ethanol in tobacco was predicted from experimental penetration data measured by this method. The results suggested that flavor cannot be distributed homogeneously through tobacco by using the operations of spraying and mixing alone.
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  • Yoshiyuki Bando, Michio Kuraishi, Makoto Nishimura, Makoto Hattori, Is ...
    1988 Volume 14 Issue 6 Pages 803-809
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The flow characteristics of the bubble column with simultaneous gas-liquid injection nozzle of gas suction type were experimentally studied. Suction gas flow rate and gas holdup increased with increasing liquid flow rate. The performance of the present nozzle was compared to that of the injection nozzle of air-lift type reported previously.
    Under the present experimental conditions, optimal dimensions of nozzle assembly for suction gas flow rate were found to be as follows :
    (nozzle length) / (nozzle diameter) = 20 30
    (orifice diameter) / (nozzle diameter) = 0.5 0.6
    Suction gas flow rate per unit power increased with increasing nozzle diameter in the range of nozzle diameter less than 30 mm. On the other hand, optimal nozzle diameter for gas holdup varied with operating conditions.
    Two different flow sections, spouting and calm, were observed in the column and smaller bubble diameter, higher gas holdup, and larger specificgas-liquid interfacial area were obtained, as in the column with air-lift nozzle. Energy efficiencies for gas holdup and interfacial area were higher with gas-suction nozzle than with air-lift nozzle.
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  • Ikuho Yamada, Hideki Mori, Yoshihito Kato, Tsutomu Aragaki, Setsuro Hi ...
    1988 Volume 14 Issue 6 Pages 810-817
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The concept of hypothetical pinch plate, used in solving the minimum reflux problem for conventional multicomponent distillation columns, is applied to solving the same problem for two types of complex distillation columns--one with two feed plates and the other with a sidecut plate between two feed plates--which are useful for energy saving in the distillation process. The characteristics of the proposed method are as follows :
    1) An infinite number of plates are assigned to each section of the column in accordance with the definition of minimum reflux problems. It is assumed that the real pinch point is located in the middle of each section of the column regardless of the existence of nondistributed components.
    2) A finite number of plates are assigned to a portion adjacent to the feed and sidecut plates.
    3) The hypothetical pinch plates are assigned to the two ends of the portion mentioned in 2), and an infinite number of plates exist between the real pinch point and the hypothetical pinch plates.
    4) The normalized θ-method based on the component material balance is used for correcting assumed values of liquid composition on the hypothetical pinch plates.
    The usefulness of the proposed method and the location of the pinch point in each section of the column are illustrated by numerical examples for each of the two types of complex columns.
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  • Yasutoshi Shimizu, Minoru Rokudai, Sachio Tohya, Eisuke Kayawake, Tets ...
    1988 Volume 14 Issue 6 Pages 818-824
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Before filtration tests to apply ceramic membranes to anaerobic fermentation membrane bioreactors, the suspended solids in anaerobic waste were characterized as the feed to the membranes. The anaerobic waste was made from anaerobic digestion of a synthesized waste containing glucose and peptone. The suspended solids were found to consist mainly of methanogenic bacteria and these metabolites. They were spheres 0.05μm in diameter, colli (0.21 μm in diameter) and rods (0.20.7μm ×12μm). When these particles formed a packed layer on the membrane by filtration, particles changed shape due to the filtration pressure. Specific filtration resistance was governed by the salt concentration. The resistance increased with increasing salt concentration. The results were explained by the DLVO theory.
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  • Yasunobu Hiraoka, Akira Tomizawa, Tatsuki Oguchi, Masanobu Koutate
    1988 Volume 14 Issue 6 Pages 825-830
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The limiting current density of reconstituted cheese whey solution was investigated by using a labscale electrodialyzer. Only anion exchange membranes were arranged in the unit. The surfaces of the membranes were washed manually with water and then with detergents before each test. The limiting current density was not determined by the method in which voltage across the membranes increases with time when a certain current is applied, but was found clearly by I-V plot.
    The limiting current density of the reconstituted whey solution was proportional to the temperature and to the linear velocity of the solution in power of 0.73.
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  • Osamu Hashimoto, Shigekatsu Mori, Setsurou Hiraoka, Ikuho Yamada, Taka ...
    1988 Volume 14 Issue 6 Pages 831-835
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    To obtain the fundamental data for designing the particle circulation system of a new turbulent fluidized-bed catalytic reactor, the elutriation rate of particles from a turbulent fluidized bed was observed for two kinds of particles by using a cold model. Both kinds of particles used in the experiment were classified as group A particles of the Geldart map. The particles were almost the same size, sbout 65 μm, but the densities of the two kinds were different--1, 580 kg/m3 and 2, 150 kg/m3, respectively.
    Based on the experimental results obtained in this work, the Tanaka-Shinohara equation previously proposed for estimating the elutriation rate constant Ki* was modified, and the following a new equation was obtained.
    Ki*g (u0-ut) =0.91· [(u0-ut) 2/g·dpi] 1.2· (ρpgg) -1.1
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  • Ryoichi Nagata, Shinichiro Gondo
    1988 Volume 14 Issue 6 Pages 836-840
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The rate constants of mutual isomerization in aqueous solutions of α- and β-D-glucose were measured using a glucose sensor. The measurements were made in 0.05M sodium acetate buffer solution of pH 4.5-7.5 at temperatures of 15-25°C and at D-glucose concentrations of 0.1-0.5 g/l.
    For the range of pH and that of D-glucose concentration mentioned above, the rate constant of conversion from α-to /β-D-glucose was estimated as 7.1×10-3min -1 (15°C) -1.9× 10-2min-1 (25°C) and that of the reverse reaction as 3.9×10-3min-1 (15°C) -1.1 × 10-2min-2 (25°C).
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  • Ikuro Shishido, Yukio Suzuki, Mutsumi Suzuki
    1988 Volume 14 Issue 6 Pages 841-844
    Published: November 10, 1988
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A prediction method for the heat transfer characteristics of a cascade heat pipe is developed by solving nonlinear simultaneous equations.
    It is shown that this method predicts well the experimental values of the heat tranfer rate. It is confirmed that the heat transfer characteristics of cascade heat pipes such as thermal diode and thermal switching are predicted satisfactorily by this method.
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