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Volume 6, Issue 3
Displaying 1-18 of 18 articles from this issue
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ISAMU NAGATA, TATSUHIKO OHTA1973 Volume 6 Issue 3 Pages 211-214
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSA method is presented for predicting vapor compositions from ternary total pressure data. The Wilson equation is employed to represent liquid activity coefficients. Calculated results for seven isothermal ternary nonideal systems are in good agreement with the experimental data. These results are compared with those obtained from binary data in a previous paper.
Binary vapor-liquid equilibrium data are also predicted by using the equivalent binary parameters determined by this method.View full abstractDownload PDF (608K) -
ISAMU NAGATA, TOSHIRO YAMADA1973 Volume 6 Issue 3 Pages 215-219
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSA computer algorithm is presented to obtain best parameters of local composition equations. The Simplex method is found to be one of the most effective parameterseeking methods. Numerical calculations are illustrated by a simultaneous fit of excess Gibbs free energy and excess enthalpy of mixing data for the ethanol-cyclohexane system using the Wilson, Heil, and NRTL equations, whose parameters are assumed to vary linearly with temperature.View full abstractDownload PDF (734K) -
YASUHIDE NISHI1973 Volume 6 Issue 3 Pages 220-223
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSBy use of Eq.(1), vapor-liquid equilibria for the following five systems were predicted from binary x-y-t data, and compared with literature values and estimated values by other methods.
logKi = Ai/T + Bi (1)
System A : isopropanol-water-isopropyl ether
System B : methanol-ethanol-water
System C : ethanol-isopropanol-water
System D : methanol-ethanol-isopropanol-water
System E : l-hexadecene-n-tetradecane-naphthalene
These systems are hypothetical reaction systems. For example, the following hypothetical reaction is considered for System A.
2 isopropanol →← isopropyl ether + water
In Eq.(1) Ai is a constant determined by reaction system and component, and Bi is a constant determined from binary x-y-t data for liquid composition at hypothetical conversion 0 and/or 1.
As a conclusion, it was found that the predicted values agree well with the literature values, and that Eq.(1) may be used with nearly equal accuracy to other equations.View full abstractDownload PDF (638K) -
TOMOSHIGE NITTA, TAKASHI KATAYAMA1973 Volume 6 Issue 3 Pages 224-230
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSThe vapor-liquid equilibrium and heat of mixing data for binary mixtures of alcohols- nonpolar substances are analyzed by using a continuous linear association model. New sets of values for association constant and enthalpy of hydrogen bond formation for aliphatic alcohols are presented which represent vapor-liquid equilibria better than the sets by Renon and Prausnitz. The physical interaction parameter, which has been treated so far as an adjustable parameter, is correlated satisfactorily with solubility parameter and branching parameter. The estimation of vapor-liquid equilibria for alcohol-hydrocarbon systems is possible by use of the correlation.View full abstractDownload PDF (1120K) -
SHIRO ITO, KOHEI OGAWA1973 Volume 6 Issue 3 Pages 231-235
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSThe eddy viscosity and the representative mixing time and length, which are the most indispensable basic informations in studying turbulent mixing phenomena, are investigated theoretically and experimentally.
The new eddy viscosity is defined as the product of kinematic viscosity and coefficient which relates the turbulence energy dissipation through fluctuating motion with that through mean motion. The turbulent flow field being looked upon as the flow field in which the turbulent elements move transverse to the mean flow, new representative mixing time and length are proposed. The representative mixing time is applied to relate the above eddy viscosity with the mean velocity gradient. Being different from the conventional eddy viscosity, the newly defined eddy viscosity is determined uniquely on the notice point if there is only one mean velocity gradient to any direction at that point.
In the transitional region from laminar to turbulent flow of liquid in a circular pipe, experimental values of the newly defined eddy viscosity and the representative mixing length are obtained by measuring the liquid velocity fluctuations by an electro-chemical technique based on an electro-chemical reaction controlled by diffusional mass transfer rate.View full abstractDownload PDF (858K) -
Determination of Expression CoefficientKUNIO ATSUMI, TETSUO AKIYAMA, SABURO MIYAGAWA1973 Volume 6 Issue 3 Pages 236-240
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSA method to determine the expression coefficient is developed employing a weighted residual method, and is successfully applied to the expression of a slurry of titanium dioxide in water.
It is found that the expression coefficient, which has been reported to be dependent on the void ratio, is also strongly dependent on the initial void ratio of the slurry, ranging from 1.86 to 3.30 in the present study.
The basic equation of the expression process with a Lagrangian variable is analyzed, using the experimentally determined coefficient. A finite difference method and a moment method are used to solve the basic equation. The expression ratio is computed and compared with experimental results, with excellent agreement.View full abstractDownload PDF (733K) -
ALEKSANDAR TOLIÇ, TERUKATSU MIYAUGHI1973 Volume 6 Issue 3 Pages 241-246
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSTwo new graphical methods are presented for the calculation of equilibrium stages (ND) for countercurrent extractors in which hackmixing is the only controlling factor for mass transfer.
Both proposed methods are based on a stagewise model with back-flow. One method is developed for the calculation of ND for one-solute distribution and the other is developed for two dependent solutes distribution. The proposed graphical solutions for the two methods are different, but both can be straight-forwardly applied to the case of equilibrium distribution.View full abstractDownload PDF (864K) -
EIZO SADA, TAKAAKI AMENO1973 Volume 6 Issue 3 Pages 247-251
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSA problem of mass transfer with an instantaneous irreversible reaction was solved by introducing a concept of negative concentration and sometransformation variables to change the problem of a moving boundary to that of a nonlinear differential equation and using the finite difference method.
The solution thus obtained is in good agreement with that of Sherwood and Pigford in an initial period. In the latter half period, however, the moving velocity of the reaction plane is accelerated and the results deviate from those of Sherwood and Pig ford. The reactant in liquid is exhausted within a finite time.
The movement of the reaction plane is verified from experiments.View full abstractDownload PDF (676K) -
MITSUO MURATA, SHOZABURO SAITO, AKIRA AMANO, SIRO MAEDA1973 Volume 6 Issue 3 Pages 252-258
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSThe extension of the free-radical chain mechanism to heavy paraffinic hydrocarbons has been studied for practical purposes. A generalization of the mechanism is attempted based on the Markov chain theory and presented in a form suitable to computer analysis. This generalization allows easier prediction of the distributions of initial pyrolytic products. Better agreement with experimental results is achieved by taking into account the equilibrium among all the possible isomers for higher homologues of hydrocarbon free radicals. However, the calculation of products is complicated by inclusion of radical isomerization which has not been ascertained experimentally. A new model is constructed herein by avoiding a direct approach to the problem of isomerization, while preserving its effect on the distribution of products. In this treatment, radical isomerization is replaced by a hypothetical process that accompanies the decrease of primary radicals and the increase of secondary radicals. The initial product distributions predicted by the model show good agreement with the observations for a series of normal paraffins from n-butane to n-hexadecane.View full abstractDownload PDF (1150K) -
KATSUYUKI NAKANO, MASAMITSU MOROFUJI, SHINIGHIRO GONDO, KOIGHIRO KUSUN ...1973 Volume 6 Issue 3 Pages 259-263
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSIn order to clarify the relationship between operating conditions and selectivity of a consecutive reaction system, the vapour-phase hydrogenation of chlorobenzene on a rhodium-alumina catalyst was studied and the reaction mechanisms in the first and the second stage reaction processes were expressed by a Langmuir-Hinshelwood type of rate law. Hydrogen is considered to be adsorbed atomically without strong competition with organic components.
The selectivity of benzene increased at high reaction temperatures and low partial pressures of hydrogen. In the external diffusion-controlled region, the selectivity of benzene was reduced compared with that obtained in the reaction-controlled region.View full abstractDownload PDF (793K) -
KATSUMI NAGASAKA, MASARU SHIMIZU, SAGHIO SUGIYAMA1973 Volume 6 Issue 3 Pages 264-268
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSThe necessary radius and length of material to avoid end effect in determining thermal conductivity by the transient method is discussed mathematically and experimentally. It is found that the dimensions of the material can be determined by the conditions b>5√ (Eq.(24)), and i≥ (π/0.4)√(Eq.(30)), by using the data after the elapsed time given by t> 20a2⁄a (Eq.(16)). These critical conditions are demonstrated to be valid experimentally and may be applied widely to the transient method.View full abstractDownload PDF (708K) -
NORIAKI WAKAO, YOSHINOBU TAKANO, D. G. T. PEI1973 Volume 6 Issue 3 Pages 269-270
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSThe Nusselt number for heat transfer between particle and stagnant fluid in packed beds is theoretically computed and found to be Nu=2.0. This may be regarded as the lower limiting Nusselt number for beds where each particle is in good contact with flowing fluid.View full abstractDownload PDF (254K) -
LE VAN TAM, TERUKATSU MIYAUCHI1973 Volume 6 Issue 3 Pages 271-272
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSA computational investigation of parametric pumping accompanied by a reversible reaction of the type 2A→←B+C is presented. Calculated results show that the parametric pumping effect of one of the products considerably improves the conversion because of the dual function of the catalytic surface-acting as a catalyst and accomplishing a parapump separation. Better conversion (68% as compared with equilibrium conversion of 50%) and remarkable separation factor are obtained.View full abstractDownload PDF (298K) -
TOYOHIKO HAYAKAWA, MASATOMO SHIGETA1973 Volume 6 Issue 3 Pages 273-275
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSA new spray column-type extractor, in which the gas (air) was injected from the inside tube (0.2φ I.D.) into a liquid droplet (toluene or toluene+24.5wt% CCl4) flowing from the annular space of the double tube (outside tube: 0.65φ, 1.10φ and 2.80φ I.D.), liquid droplets combined with gas bubbles ( = two-phase droplets) were formed at the tip of a nozzle, and the solute (acetic acid) in droplets was extracted with water, is proposed. The density of dispersed-phase liquid, the volume ratio of gas to oil in the two-phase droplet and the nozzle diameter were varied, and the results showed that the increase of the volume ratio of gas to oil in the two-phase droplet led to high efficiency of the extraction.View full abstractDownload PDF (431K) -
HISAYOSHI MATSUYAMA1973 Volume 6 Issue 3 Pages 276-277
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSThis paper presents a sufficient condition for the existence of a unique equilibrium state in an adiabatic tubular reactor in which a single exothermic chemical reaction takes place and Peclet number for mass transfer is equal to that for heat transfer. The condition is obtained by analyzing the relations between properties of the heat generation curve for an adiabatic tubular reactor and those of the curve for an adiabatic complete mixing reactor with the same residence time, inlet temperature and inlet concentration as the tubular reactor, and is given in terms of the character of the heat generation curve for the complete mixing reactor, which can be analyzed much more easily than the tubular reactor. Compared with other conditions for a first-order reaction, the condition is shown to be stronger than the condition of Luss and Amundson for equilibrium states with small Peclet numbers and low temperature, but more conservative for equilibrium states with large Peclet numbers.View full abstractDownload PDF (340K) -
HIROAKI MASUDA, YOSHIFUMI ITO, KOIGHI IINOYA1973 Volume 6 Issue 3 Pages 278-282
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSMeasurement of gas flow rate in gas-solids two-phase flow is studied both theoretically and experimentally by use of a horizontal diffuser. Since the pressure recovery in the diffuser varies with both the solid flow rate and diffuser length, the gas flow rate measured by the diffuser generally has some error. The relative error for the measurements is a monotone-increasing function of the measuring length, but never exceeds the value of the mass flow ratio. It is also shown that there is a length at which the error vanishes. This length can be estimated using an analytical equation. The effects of powder properties on the magnitude of the error are also discussed in detail.View full abstractDownload PDF (942K) -
RUDOLPH E. LISA, RONALD G. BARILE1973 Volume 6 Issue 3 Pages 283-284
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSThe data of Yamazaki and Miyauchi9) for heat transfer between emulsion phase and gas bubbles in fluid-bed catalytic contactors are analyzed in terms of the Bubbling Bed Model of Kunii and Levenspiel5). It is shown that the effective bubble size needed to fit the Bubbling Bed Model to the reported transport rates is much smaller than the actual bubble size; however, more realistic assumptions regarding temperature measurements indicate that their reported transport rates are much too high. Temperature-corrected data are shown to be reasonably estimated by the Bubbling Bed Model using the measured bubble size.View full abstractDownload PDF (376K) -
MASAO YAMAZAKI, TERUKATSU MIYAUCHI1973 Volume 6 Issue 3 Pages 285-286
Published: August 31, 1973
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSAn answer has been given to the question raised by Lisa and Barile in relation to the correction of time constant of the measuring probe utilized for the experimental work on overall heat-transfer in a fluid bed operated at relatively higher gas velocity. The question has been examined in detail. Experimental coefficients corrected for the time constant have turned out not being consistent with their method, but having supported the previous conclusion.View full abstractDownload PDF (313K)
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