KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 3 , Issue 4
Showing 1-18 articles out of 18 articles from the selected issue
  • Teruhiko Sugimori, Shinzo Nishikawa
    1977 Volume 3 Issue 4 Pages 323-330
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The precipitation polymerization of acrylonitrile was carried out in aqueous solution initiated by Na2S2O5/NaNO2 redox catalyst system to analyze the reaction process of precipitation polymerization over a wide range of conversion.
    The experimental results can be explained by the following. Reaction takes place individually, both in the liquid phase in which monomer is dissolved in water, and in the polymer phase formed by the precipitation of the polymer. A part of monomer is adsorbed in the precipitated polymer. Radicals in the liquid phase are able to enter into the polymer phase with the aid of collision and then monomer radicals generated in a polymer particle by chain transfer reaction are able to escape from the polymer particle with the aid of diffusion.
    Based on this reaction scheme, the equation of the over-all reaction rate was derived and then the apparent velocity coefficients were obtained. These values approximately agreed with the values obtained in the homogeneous reaction in several solvents.
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  • Teruhiko Sugimori, Hiroshi Akiyama, Yoshijiro Tabara
    1977 Volume 3 Issue 4 Pages 331-337
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    In order to clarify the effects of the fluid mixing on the course of precipitation polymerization, the polymerization of acrylonitrile initiated by redox catalyst system in aqueous solution was carried out continuously both in a stirred tank reactor with helical ribbon mixer and in the same reactor equipped with a centrifugal pump to circulate the reactant.
    The monomer conversion and the average degree of polymerization were increased with the increased fluid mixing. These experimental results can be explained by the following : Reaction takes place both in the liquid phase, in which monomer is dissolved in water, and in the polymer phase formed by precipitation of the polymer. Concentrations of monomer in the two phases is independent of the degree of fluid mixing but the number of radicals in a polymer particle is increased with increased fluid mixing. Radicals in the liquid phase entered into the polymer phase by means of collision and then monomer radicals generated in a polymer particle by chain transfer reaction escaped from the polymer phase by means of diffusion under the control of film resistance at the surface of a polymer particle.
    Therefore, the equation, applied effectively for design and determination of operating conditions, was derived.
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  • Kunio Kato, Makoto Inomata, Kazuhiko Onoda, Masanori Yamagishi
    1977 Volume 3 Issue 4 Pages 338-343
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Since fluidized particles can be easily fed to and discharged from a packed fluidized bed, a packed fluidized bed can be used as an industrial reactor for the reaction of rapid catalyst deactivation systems.
    The purpose of this work was to obtain basic knowledge for design and operation of a packed fluidized bed catalytic reactor
    Catalytic cracking of cumene in the case of zero catalyst deactivation was investigated in fixed bed and a packed fluidized bed, and reactant conversion was analyzed by the two phase model with known reaction rate catalyst. These calculated conversions agreed well with corresponding experimental conversions.
    The reactant conversion of catalyst decay reaction in a packed fluidized bed in the case of continuous feed and discharge of catalyst was analyzed numerically. If the reaction with large reaction rate constant is performed in a packed fluidized bed, the catalyst bed height to obtain a designed conversion becomes small and the reactant conversion is approximately calculated by assuming the catalyst particles in the bed being perfectly mixed. On the other hand, if the reaction with small reaction rate constant is performed in a packed fluidized bed, catalyst bed height to get a designed conversion becomes large and the reactant conversion is approximately calculated by assuming the catalyst particles in the bed as being plug flow.
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  • Toshimasa Hirama, Midori Yumiyama, Minoru Tomita, Hiroshi Yamaguchi
    1977 Volume 3 Issue 4 Pages 344-348
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A study was made of the lateral heat transfer in a packed fluidized bed in which fluidizing particles flowed horizontally. The lateral thermal diffusivities αrp based on the one-dimensional diffusion theory were calculated from temperature profiles measured in the bed
    The lateral thermal diffusivity was found to be negligibly affected by the feed rate of particles and a correlation of αfp was derived from the random wake theory as
    αrp=0.112fpDp (Lf/Lmf) (u-umf)
    where, fp is the ratio of the volume of particles moving with the bubble to the volume of the bubble, Dp is diameter of fixed packing, Lf is bed height, Lmf is bed height at incipient fluidization, u is gas velocity corrected for fixed packing voidage and umf is gas velocity at incipient fluidization. And fp was correlated with the wake fraction fw in conventional fluidized beds as
    fp =fw/3 (1-fw)
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  • Kiyotaka Sakai, Naoaki Fujita, Tadashi Shirotsuka
    1977 Volume 3 Issue 4 Pages 349-353
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The modified Karlovitz numbers previously proposed was found to be short of exactness in its theoretical derivation. We derived, therefore, the new modified Karlovitz number both by taking into account concentration change of activated particle caused by flame stretch and also by using a more stringent technique for approximation. It was shown that this KMnew* predicts well the blowoff limits for hydrocarbon flames but the flame stretch must be considered more precisely to obtain better values. Assuming that the main chain carrier in combustion reactions is the oxygen atom, blow-off limits of hydrogen flames are also calculated by use of KMnew*.
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  • Hitoshi Funayama, Kojiro Ogiwara, Takuo Sugawara, Hiroyasu Ohashi
    1977 Volume 3 Issue 4 Pages 354-358
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Light distribution characteristics of the resonance and the other spectra of mercury vapor emitted from a low pressure mercury lamp were precisely examined with a sharp directional photodetector and a potassium iron (III) oxalate chemical actinometer.
    The characteristic of the self-absorptive resonance line was diffuse, and that of the other lines was also intrinsically diffuse though the latter had been assumed to be specular. A lamp, whose diameter and length were 25 mm and 870 mm, respectively, could safely be assumed a line source when it was separated from the reaction vessel by more than about 80 mm.
    It was shown by numerical examples that the differences in light distribution characteristics greatly affected the scale-up of a trough-type, a plate-type and an annular photoreactor.
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  • Teruo Takahashi, Yasuharu Akagi, Tamiya Kishimoto
    1977 Volume 3 Issue 4 Pages 359-363
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The gas and liquid velocities of incipient liquid stagnation were investigated, based on the detailed observation of behavior of gas and liquid flows on sieve tray. A sieve tray with some holes was installed in the plate column that was designed to flow from every side to the tray (Case 1). The gas and liquid velocities of incipient liquid stagnation, the ratio of hole area of dropping liquid flow to total hole area (τ) and the liquid depth on the tray were measured using this apparatus. The experimental results were correlated by the model based on the behavior of gas and liquid on the tray.
    On the other hand, the gas and liquid velocities of incipient liquid stagnation on the sieve tray without downcomer that was installed in the plate column with 0.15 m diameter were measured. This velocity was compared with the velocity in case 1 and it was evident out that these velocities could be represented by the same correlation.
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  • Nobuetsu Yutani, Naoshi Ototake
    1977 Volume 3 Issue 4 Pages 364-370
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The macroscopic behavior of particles in randomly fluctuating velocity was analyzed theoretically.
    Hitherto the behavior of particles has been dealt with by dynamic theory under the assumptions of continuous and also of homogeneous state, but by these methods it seems to be impossible to account for the diffusional phenomena in the system which results from microscopic and individual movement of particles.
    In this study, a treatment is developed for the systems composed of particles which are in random motion, and results are obtained theoretically about the axial velocity profile and the self diffusivity of particles.
    Furthermore, the dispersion coefficient of particles in unsteady state can be defined and be related with the self diffusivity in steady state.
    The theoretical considerations treated here are expected to apply to industrial problems.
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  • Yoshinori Nagashima, Shinichi Maeda
    1977 Volume 3 Issue 4 Pages 371-375
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Mixing of fluid in a model horizontal crystallizer was experimentally investigated prior to the construction of a plant for desalination of the sea water by freezing method. It is important to know the distribution function of residence time of the crystallizer because the distribution of crystal size is affected by it.
    The pulse of concentration was injected spontaneously at the inlet and we measured the response of its concentration at the model crystallizer, which was constructed with the same dimension as the actual crystallizer except half the width. The reverse flow ratio was decided by comparison between the curve of function of the calculated residence time distribution of the fluid and that of observed ones.
    The reverse flow ratio calculated on the base of these data agreed well with the ratio obtained on the actual plant.
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  • Yoshiharu Murata, Nobuyasu Meguri
    1977 Volume 3 Issue 4 Pages 376-378
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The extraneous agents which form intermolecular compounds with aromatic compounds were systematically investigated for adductive crystallization.
    The experimental results suggest that tert. Butylalcohol is a good agent for the separation of phenol is compounds, and that 2, 4 dichlorotoluene can be used for the separation of chloro and nitro derivatives.
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  • Yoshiharu Murata, Taijiro Honda
    1977 Volume 3 Issue 4 Pages 379-383
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    In the crystallization, it has been a interesting subject to verify a reciprocity relation of the growth kinetics measured in a single crystal with that measured in a suspension. In this study, using mCNB-oCNB system in which the influence of the volume diffusion step on the overall growth rate can be ignored, a mass of growth mCNB crystal in a suspension was measured by two methods. In one of these, a seeding crystal was of uniform size and in another. A nucleation took place at the beginning of the run and the generated nuclei grew to a large, about 1 mm in the metastable state.
    The results obtained are compared with calculated values by the growth rate which was determined for single crystal growth in our previous paper.
    It was found that observed values were in good agreement with estimated ones when distribution of crystal size was relatively small and supersaturation was controlled.
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  • Katsuyuki Kubota, Shinya Hayashi, Shuichi Mizugami
    1977 Volume 3 Issue 4 Pages 384-391
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The following study deals with the equipment design of a foam separation technique used for removal of an anionic surfactant, sodium dodecylbenzenesulfonate, from its aqueous solution. This technique eliminates the use of the bubble size parameter which is difficult to control and measure. Two possible methods are feasible in the design of a multistage foaming equipment. One is similar to the multistage concurrent ion exchanger design which takes account of the interrelationships of experimental surface excess equilibrium, bubble diameter and foamate, while the other method which this paper presents is based on the interrelationships of the foamate concentration, the foamate and pool concentration under a given experimental equipment. In this study, the latter method which the bubble diameter is included as an implicit function proves to be preferable to the former because here the surface excess depends on the pool depth and the bubble diameter which is also a weak function of the bulk concentration.
    For this study, a 4-stage foaming equipment was utilized which was operated under the optimum gas flow rates, and discrepancies between the calculated and experimental values were found to be small.
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  • Yoshinobu Kawano, Fumiyuki Nakashio
    1977 Volume 3 Issue 4 Pages 392-397
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A theoretical investigation has been made of the effect of an interfacial reaction upon the rate of extraction, where an irreversible reaction, A (aq) + B (org)C (org), is carried out at the tangential moving interface, and the overall rate of the interfacial reaction, R, is given by R =kCAmCBn.
    The basic equations for both liquid phases in cocurrent, laminar, stratified flow between two parallel flat plates were numerically solved to obtain the average extraction rate of the component A. The average extraction rate was given as a function of several dimensionless parameters; Graetz number, the ratio of the interfacial reaction rate to the diffusion rate, the reaction order, the initial concentration ratio between A and B etc. The average extraction rate was greatly influenced by the interfacial reaction in the case of high Graetz number, that is, short contacting time.
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  • Atsushi Endo, Mutsumi Suzuki, Shigemori Ohtani
    1977 Volume 3 Issue 4 Pages 398-405
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Concentration distribution and mass transfer rate are calculated for cylinder and coaxial annular cylinder models of stagnant boundary film with heterogeneous boundary conditions, in which stripes or circles of active and inactive surfaces are regularly arranged on a boundary surface.
    Parameters appeared in these models are the fraction of the active area φ, and dimensionless ratios δ/γ2 (or l2, γ12) or the number of stripes N.
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  • Satoshi Ohshima, Toshiichi Takematsu, Morio Suzuki, Kazuo Shimada, Yas ...
    1977 Volume 3 Issue 4 Pages 406-410
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Studies on liquid mixing and particle bed expansion in a gas-liquid cocurrent up-flow column were made under the condition that packing particles were in the state ranging from subsided state to fluidized state and also in a fixed state.
    Spherical glass particles with average diameters of 0.15, 0.20, 0.28 and 0.43 cm were used as packing particles. Superficial liquid and gas velocities based on an empty column were 0.64.3 cm/sec and 06.3 cm/sec, respectively. Péclet number for liquid mixing, (Pe) l, was found to have an approximately constant value of 1.2 under the condition that the particle bed was in the fixed state or that the value of ul/ulmf was below 0.35 in the free state. This value of (Pe) l was significantly larger than those reported in literatures on liquid mixing in cocurrent or countercurrent liquid down-flow packed beds.
    Under the condition that the particle bed expanded, the value of (Pe) l decreased with the increase of bed expansion. Liquid mixing in upward liquid single flow through packed and fluidized beds was also studied and discussed in comparison with that in downward single flow.
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  • Kiyoharu Ishida, Katsuji Noda
    1977 Volume 3 Issue 4 Pages 411-415
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Ternary liquid-liquid equilibrium data are obtained for the n-heptane-n-butyl mercaptan-ammonia and n-heptane-diethyl sulfide-ammonia systems at 0°C and 20°C. Five methods for the estimation of the plait point are shown and compared with one another. The agreement among these estimated values is generally good. In these methods Othmer-Tobias co-ordinates may be useful for the systems which are difficult to estimate the plait point by Hand-Treybal method.
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  • Sukekuni Mukataka, Hiroshi Kataoka, Joji Takahashi
    1977 Volume 3 Issue 4 Pages 416-421
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A circulation flow model in which macro-mixing of liquid bulk and micro-mixing around mycelia are taken into consideration has been proposed for a submerged culture of filamentous mold in a stirred fermenter. In this model, the circulation time distribution of liquid is considered as a macro-mixing, and the degree of micro-mixing is represented by a volume of segregated liquid around the unit mass of mycelia.
    The circulation time distribution in a mycelial suspension of Penicillium chrysogenum was measured with a magnetic particle tracer, and the distribution was found to be represented by the logarithmic normal-probability distribution. The volume of segregated liquid around the mycelia was calculated from this circulation time distribution and the over-all specific respiration rate. The volume thus calculated was independent of the mycelial concentration over 6 g/l, while the volume was increased as the power consumption increased.
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  • Hiroshi Yokoyama, Hiroshi Hara, Koji Shimada, Minoru Kumagai, Kazuo En ...
    1977 Volume 3 Issue 4 Pages 422-428
    Published: July 10, 1977
    Released: October 21, 2009
    JOURNALS FREE ACCESS
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