KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 13 , Issue 6
Showing 1-24 articles out of 24 articles from the selected issue
  • Susumu Yoshioka, Tadayoshi Murakami, Katsuya Ohki, Kimihiro Nonaka
    1987 Volume 13 Issue 6 Pages 721-727
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Combustion tests using Datung-coal were carried out in an experimental fluidized-bed combustor with a grid-type internal baffle. Effects of the baffle on combustion characteristics, especially in desulfurization efficiency, were investigated. The combustor was 0.155 m in I.D. Static bed heigh was 0.4 m. The baffle was placed 0.45 m above the air distributor.
    The installation of the baffle markedly improved the desulfurization efficiency. The oxygen concentration in the bed below the baffle was found to increase. It was concluded that the improvement in desulfurization efficiency resulted from the faster sulfation rate of CaO in the more oxidative atmosphere.
    Download PDF (960K)
  • Tetsuro Adachi, Tosio Sawa, Sankichi Takahashi, Toshikazu Sindo
    1987 Volume 13 Issue 6 Pages 728-733
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The characteristics of precoating for a precoat filter using powdered ion exchange resin as filter aid were investigated with 1.5 meters long filter elements.
    The characteristics of precoating (thickness and distribution of precoat layer) were evaluated at various operating conditions.
    The results showed that the factors controlling them were size of resin flock and ascending velocity of water in the filter vessel.
    The size of resin flock was affected by reflocculation of resin flock, and operating conditions causing reflocculation were investigated.
    Consequently, it seemed that reflocculation depended on the maximum value of resin concentration in the filter vessel.
    In addition, a relation between sedimentation rate of resin flock and ascending velocity in the filter vessel was noticed by simulation of distribution of ascending velocity and effects on characteristics of precoating were evaluated.
    Download PDF (898K)
  • BohYoh Shibata, Yoshifumi Tsuge, Hisayoshi Matsuyama, Eiji O'Shima
    1987 Volume 13 Issue 6 Pages 734-740
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    A method for fault diagnosis of a continuous process with load fluctuations has been developed. It consists of two algorithms, one an efficient algorithm for data rectification developed by introducing Akaike's Information Criterion and the other a fault diagnosis algorithm utilizing the signed directed graph. The former detects abnormal values of the state variables in the process with load fluctuations and supplies them to the latter. The latter searches candidates for the origin of failure which can explain all the abnormal values detected by the former. The efficency of this method is demonstrated by applying it to three types of miniature pipelines with different configurations.
    Download PDF (1052K)
  • Yoshihiko Ninomiya, Toshiyuki Mori, Mitsuho Hirato
    1987 Volume 13 Issue 6 Pages 741-748
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Experiments were performed to investigate heat transfer characteristics of coal-water mixture (CWM) of a concentration range of 27 to 60 wt% flowing through a horizontal pipe. The data were obtained in laminar flow and for uniform wall temperature conditions.
    The Nusselt number of low-concentration CWM (up to about 49 wt%), which was characterized as a Newtonian fluid, was correlated by conventional heat transfer equations with the thermal conductivity of CWM for a stationary condition. In the case of highly loaded CWM, which had psuedo-plastic characteristics, the Nusselt number was two to three times greater than that calculated from the conductivity of the stationary CWM assuming Bingham flow. This result shows the presence of thermal conductivity enhancement in highly loaded conditions.
    To explain this enhancement effect, a model is proposed based on the concept of radial mixing of interstitial water induced by particle motion under a shear field. This model's predictions are in good agreement with heat transfer data of three coal-water mixtures of different particle-size distributions.
    Download PDF (1325K)
  • Kunihisa Osasa, Masao Sambuichi, Hideo Nakakura, Kazuki Tabata
    1987 Volume 13 Issue 6 Pages 749-755
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The effect of particle-size distribution on the sedimentation stability of highly loaded coal-water slurry (CWS) was examined experimentally by static laboratory sedimentation tests. The CWS was prepared by using coal samples representing different coalification with optimum concentrations of additives. The maximum stability of CWS was achieved at distribution modulus q_??_0.28 of the Gaudin-Schuhmann size distribution. The corresponding value to obtain minimum viscosity in view of the packing efficiency of particles was considerably higher (q_??_0.43), a value which agreed with the results obtained by other investigators.
    Download PDF (1241K)
  • Mitsuo Kamiwano, Fumio Saito, Yukinobu Kurata, Hideo Takino
    1987 Volume 13 Issue 6 Pages 756-763
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    A method for measuring fluid turbulence with an aid of an area-type image sensor is developed in this work. The equipment consists of a probe, an area-type image sensor having a parallel scanning mode and a circuit for high-speed processing of signals from the image sensor. The role of the probe, consisting of an image fiber, a light guide fiber and a micro lens, is mainly to transfer accurately the images of tracer particles flowing into a small observing space set in a unit toward the image sensor. The roles of the circuit are to digitize the analog signals from the sensor to let the processed signals under a particular mode be memorized by the RAM.
    The flow velocity of liquid in a stirred vessel was measured by using this proposed method, as a demonstration. The power spectra of turbulence in two flow directions are shown in this paper.
    It may be possible to measure not only mean flow velocity but also liquid turbulence in any unit by applying this method.
    Download PDF (2792K)
  • Yu-Jun Hao, Tatsuo Tanaka
    1987 Volume 13 Issue 6 Pages 764-772
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    For the rate analysis of a solid-solid reaction controlled by unidirectional diffusion, Jander first proposed a model that has been realized only in the case of comparatively small conversion of up to 0.3. Komatsu proposed a model in which a component diffuses through the points in contact with the other component. However, various defects have been pointed out in the Komatsu model, particularly in evaluating the number of contact points between the different kind of particles.
    The present paper deals with a reaction model in which the reaction rate is controlled by diffusion through the reacted layers starting with the contact points. The reaction is divided into two stages by the time when the separate reacted layers hit each other. The time is dependent only upon the number of contact points, which in turn is calculated from the initial size ratio and the volume fraction. Hence conversion can be obtained nearly up to unity as a specific function of time. The conversion as a function of time is confirmed by the experimental data of various solid-solid reaction systems reported so far, in which the number of contact points ranges from 4 to over 100.
    Download PDF (1299K)
  • Yoshiyuki Bando, Makoto Nishimura, Michio Kuraishi, Makoto Masuda, Hir ...
    1987 Volume 13 Issue 6 Pages 773-779
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The effect of thermal and optical properties of the transparent plate on the collection characteristics of the “Volume Heat Trap” solar collector was studied theoretically and experimentally.
    For collectors with transparent plates of different material and thickness, the time changes of temperature distribution were measured in the indoor and the outdoor experiments. The results calculated, taking the natural convection within the working fluid layer into consideration, were compared with the experimental data.
    It was found that the collection characteristics of the “Volume Heat Trap” collector greatly depended upon both the thermal resistance and the transmittance of the transparent plate. While the transmittance decreased and the thermal resistance increased with increasing thickness of the transparent plate, the optimum thickness of the transparent plate for collection efficiency increased with increasing temperature level. In the case where convective heat transfer coefficient on the upper surface of the plate was large, the thermal resistance of the transparent plate greatly contributed to suppression of heat loss. It was expected that the wavelength-selective transmittance of the plate would improve the collection efficiency when the convective coefficient was low.
    Download PDF (1305K)
  • Norio Kimura, Hidetoshi Mori, Yoshihiro Murase, Satoru Jingasa, Mompei ...
    1987 Volume 13 Issue 6 Pages 780-787
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    To obtain a simplified method for predicting the collection efficiency of granularbed filters with dust loads, an approximate expression representing the collection efficiency of a single sphere is presented. This expression is based on the interception model proposed in the previous paper for fibrous mat filters and on the Kuwabara-Happel cell flow for multiple spheres.
    The increment of a single-sphere collection efficiency due to dust loads was derived by assuming that aerosol particles accumulate on a granule surface as a filtration process proceeds and interception by these captured particles is the predominant mechanism causing the increase in collection efficiency.
    The correction factor K for the mean solidity of the layers of captured particles could be determined exprimentally as a function of interception parameter NR, and the value of NR0.4K was confirmed experimentally to be independent of the inlet dust loads.
    Download PDF (1182K)
  • Haruo Yamashita, Eiichi Kunugita
    1987 Volume 13 Issue 6 Pages 788-794
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The mass-transfer effect on reaction of 1-bromooctane with thiophenoxide ion, catalyzed by tetrabutylammonium cation, was studied in an agitated vessel with a plane interface.
    In both phases-benzene and aqueous solution of 2N sodium hydroxide-the phase equilibrium of catalyst or volume ratio of the two phases and the reaction rate were measured by changing the concentration of catalyst, interfacial area or agitation speed.
    Results of the equilibrium and kinetics studies indicated that the diffusion rates of tetrabutylammonium thiophenoxide, its dimer tetrabutylammonium bromide were much lower than the chemical reaction rate in a heterogeneous system.
    Download PDF (928K)
  • Takahiro Hori, Kyoichi Saito, Shintaro Furusaki, Takanobu Sugo, Jiro O ...
    1987 Volume 13 Issue 6 Pages 795-800
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Chelating resins containing amide oxime group were synthesized by radiationinduced graft polymerization. The amount of the amide oxime groups was controlled below about 0.1 mol per kg of base polymer.
    The adsorption equilibrium of uranium from seawater on this resin was investigated. It was suggested that two neighboring amide oxime groups on the grafted chain captured one uranyl ion, and that single amide oxime ligand had little capacity for the adsorption of uranium. The adsorption equilibrium was correlated by a Langmuir-type equation. The content of neighboring amide oxime groups was 0.406×10-3 mol per kg of base polymer, which corresponded to 0.39% of the total amount of amide oxime groups.
    The apparent stoichiometric stability constant for the complex of uranyl ion with the neighboring amide oxime groups in seawater was calculated to be 10-21.7.
    Download PDF (1074K)
  • Noboru Tosaka, Takeichiro Takamatsu
    1987 Volume 13 Issue 6 Pages 801-810
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    In our previous work, an approximate analytic solution for the composition distribution through a packed column for non-ideal multicomponent systems was derived by applying the perturbation method and the method of successive approximations to the fundamental equations for the column and was evaluated.
    In this work, to improve the accuracy of the solution, concise general expressions for the known terms of the perturbation, i. e., terms consisting mainly of deviations of parameters calculated at the previous stage of successive approximations, have been derived. Moreover, to improve the accuracy of the solution to a design-type problem with the iterative use of these equations, a method of calculation is proposed to determine the optimum feed location so as to make the total packed heights for a given separation minimum.
    It is found that the solution obtained by the proposed method coincides with that by an exact numerical method.
    Download PDF (1703K)
  • Tsuyoshi Nomura, Shin-ich Nakao, Shoji Kimura
    1987 Volume 13 Issue 6 Pages 811-817
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    To study the influence of feed temperature on the concentration polarization phenomenon in ultrafiltration and on the membrane transport coefficient such as pure water permeability Lp, membrane reflection coefficient σ, and solute permeability P. ultrafiltration experiments were carried out at various temperatures with both a heat-resistant polysulfone membrane and a ceramic membrane.
    The experimental results showed that at fairly high temperature mass transfer coefficient k, which is used for correction of the concentration polarization, can be obtained by using the velocity variation method or a mass transfer correlation such as Deissler's equation.
    Volume flux increased with rise in temperature and thus the amount of solute carried to the membrane surface by the flux also increased. It was found, however, that the solute concentration at the membrane surface does not increase because the mass transfer coefficient also increases with rise in temperature and the amount of solute diffusing back to the bulk of feed increases.
    In transfer parameters, Lp increased with rise in temperature and this increase could be explained by change of viscosity of permeate solution. σ was constant independent of temperature. P changed according to change of solute diffusivity coefficient with temperature.
    Download PDF (1118K)
  • Noboru Sakai, Tadashi Chida, Teiriki Tadaki
    1987 Volume 13 Issue 6 Pages 818-824
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Carbon deposition in a nickel pellet resulting from decomposition of carbon monoxide was studied by means of thermogravimetry in a range from 773 to 1073K. A nickel pellet reduced with hydrogen was used as catalyst. The highest rate of the initial reaction was observed at 773873K. The apparent orders of the average reaction rates of the initial period-of 10 min for concentration of carbon monoxide were 0.7 and 2 at 773K and 1073K, respectively.
    A reaction model including the effect of gas diffusion within a pellet was proposed for the carbon deposition. In this model a rate expression derived from a Langmuir-Hinshelwood type mechanism was used. The calculated results agreed well with the experimental ones.
    Download PDF (953K)
  • Kiyoyuki Tsuji, Kenichi Ichikawa, Hideki Yamamoto, Junji Tokunaga
    1987 Volume 13 Issue 6 Pages 825-830
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The solubilities of oxygen and nitrogen in acetone-water mixed solvent were measured at 20, 30 and 40°C. Among these solubility values except for nitrogen at 40°C, maximum and minimum values exist in the composition range of about xA<0.1, and the solubilities increased monotonously against acetone mole fraction of mixed solvent (xA) in the range of about xA>0.1.
    For these systems, the similarity was recognized between the excess solubility on the Ostwald coefficient expression basis and the ratio of the excess molar volume to the ideal one in the composition range of 0.2<φA<1.0.
    Download PDF (670K)
  • Kaoru Onoe, Katsuhiro Inoue, Tadashi Shirotsuka
    1987 Volume 13 Issue 6 Pages 831-834
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    In the previous paper, it was made clear that high-temperature oxidation of LaNi5 could produce catalysts with large surface area. However, the increase in surface area was accompanied by an increase in crystallite size, which suffered a lowering of dispersion.
    In this study, the rates of Ni and NiO crystallite growth during thermal treatment were measured and the relation between increase in surface area and crystallite growth was examined.
    It was found that neither crystallite size of unoxidized Ni nor NiO was changed in preparation of the catalysts, and the increase in surface area was caused by stress due to volume expansion from Ni to NiO.
    Download PDF (645K)
  • Akira Yasunishi, Yutaka Tada
    1987 Volume 13 Issue 6 Pages 834-838
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Four kinds of leaves and two kinds of agricultural residues (rice husk and straw) were rapidly pyrolyzed at 873-1173K in an inert atmosphere. Yields of gas, distillate and char produced from the samples were compared with those from sample sapwood. The gas from the leaves contains less carbon monoxide and more C2, C3 and C4 hydrocarbons, especially much more ethylene, than that from the sapwood. The gas from the agricultrual residues contains much hydrogen and less carbon monoxide than that from the sapwood.
    Download PDF (664K)
  • Yasuo Hirose, Hiroshi Tachibana
    1987 Volume 13 Issue 6 Pages 838-843
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    If the feed contains micro-components and reflux ratio is extremely high, distillation problems sometimes become impossible to solve because micro-components behave in a complicated manner. The acetic acid purification problem is an example of these problems. No conventional single algorithm could solve this problem. It can be solved by a combination algorithm : to make a favorable initial profile, the successive iteration algorithm precedes the Newton-Raphson one. A detailed consideration of convergence is given in the text.
    A novel column profile of micro-components is observed : it shows three extremes in column concentration of formic acid, and two extremes for water, which we had never seen. Failure of the single algorithm comes from this novel type of profile.
    Download PDF (762K)
  • Masafumi Kuriyama, Eiji Harada, Hirotaka Konno
    1987 Volume 13 Issue 6 Pages 844-847
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    A corona wind was used to improve the performance of practical tubular heat exchangers. Rates of heat transfer were measured for each exchanger, which was exposed to a corona wind produced by applying a negative high voltage to several needle electrodes placed above the exchanger.
    The usefulness of the corona wind in improving exchanger performance was confirmed through comparison between the rates of heat transfer under corona wind and those under natural convection.
    Download PDF (1937K)
  • Hua Liang, Tatsuo Tanaka
    1987 Volume 13 Issue 6 Pages 847-849
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Thermal behavior of a dust deposit undergoing exothermic reaction can be described by a differential equation, the steady-state solution of which has been proved to exist only when a critical condition is fulfilled. The approximate relationships between criticality and the Biot Number first proposed by Thomas were too complicated for practical use, so the authors derive a much simpler formula by using the Frank-Kamenetskii approximate steadystate solution. Accuracy of the formula is further improved by comparing it with the more exact numerical solution of the basic equation of unsteadystate, obtained without approximation.
    Download PDF (463K)
  • Kenji Mishima, Kenshi Matsubara, Yasuhiko Arai, Masaru Hongo
    1987 Volume 13 Issue 6 Pages 850-853
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The vapor-liquid equilibrium relations of ethanol-water-calcium chloride and methanol-ethanol-calcium chloride systems have been measured by use of a flow-type apparatus at 25°C. The partial pressure data are reported at salt concentrations of 0, 5, 10, and 15% in mass.
    The present vapor-liquid equilibrium data were correlated by an empirical model recently proposed by Hála. It is found that the salting-out and salting-in effects on ethanol-water and methanol-ethanol mixtures by calcium chloride can be illustrated by adjusting the empirical parameter contained in the electrostatic contribution term.
    Download PDF (524K)
  • Ko Higashitani, Nobufumi Inada, Toyohiko Ochi
    1987 Volume 13 Issue 6 Pages 853-856
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The breakup behavior of flocs on the centerline of the entry flow of an orifice is investigated. Flocs composed of spherical and monodispersed styrene divinylbenzene copolymer particles of 90μm diameter are injected into the orifice contraction flow of a 24.0 wt% glycerol solution. It is found that flocs are broken before the orifice to a great extent, as well as near the orifice, but not after the orifice. It is also found that the number of particles in the largest floc that can exist in the flow without breaking is proportional to (dVz/dZ) -0.2.
    Download PDF (566K)
  • Hideki Tsuge, Koichi Terasaka, Kazuhiro Tozawa, Shin-ichi Hibino
    1987 Volume 13 Issue 6 Pages 857-860
    Published: November 10, 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The effects of various factors such as liquid viscosity, gas chamber volume, orifice diameter and gas flow rate on the volume of bubbles formed in highly viscous Newtonian liquids in the presence of pressure change in the gas chamber were investigated experimentally. Dimensionless equations were obtained by correlating these experimental results. The experimental results of previous works were also correlated by these dimensionless equations. It becomes possible to predict the bubble volume over a wide range of liquid viscosities by these correlation equations.
    Download PDF (590K)
  • 1987 Volume 13 Issue 6 Pages e1
    Published: 1987
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Download PDF (90K)
feedback
Top