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Volume 14 (1981)
- Issue 6 Pages 433-
- Issue 5 Pages 345-
- Issue 4 Pages 259-
- Issue 3 Pages 173-
- Issue 2 Pages 85-
- Issue 1 Pages 1-
Volume 14, Issue 6
Displaying 1-17 of 17 articles from this issue
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HIROYASU OHASHI, TAKUO SUGAWARA, KEN-ICHI KIKUCHI, HIROSHI KONNO1981 Volume 14 Issue 6 Pages 433-438
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
JOURNAL FREE ACCESSThe mass transfer coefficients between particles and liquid were correlated for single particles and for fixed beds with specific power group including the energy dissipation rate defined for a particle. The following empirical equations were obtained over a wide range from laminar to turbulent flow, assembling the published data including those of the authors for fixed beds:
for single particles
Sh=2+0.59(ε1/3Dp4/3/v)0.57Sc1/3
2<(ε1/3Dp4/3/v)<63000, 570<Sc<1420
for fixed beds
Sh=2+0.51(ε1/3Dp4/3/ν)0.60Sc1/3
0.2<(ε1/3Dp4/3/ν)<4600, 505<Sc<70600
where e is energy dissipation rate per unit mass of liquid flowing around a particle, Dp is particle diameter, and ν is kinematic viscosity of liquid. These equations, almost identical, are also practically the same as published ones for stirred tanks, suspended bubble columns, and twophase tube-flow. The agreement suggests that specific power group may be useful as a general parameter in the study of mass-transfer phenomena between liquid and particles where the liquid is either quiescent or turbulent and the particles are either fixed or suspended.View full abstractDownload PDF (446K) -
YOSHIO HARANO, HIDEJI YAMAMOTO, TAKESHI MIURA1981 Volume 14 Issue 6 Pages 439-444
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
JOURNAL FREE ACCESSThe homogeneous nucleation of KBrO3 in quiescent aqueous solution was measured by a differential scanning calorimeter at constant cooling rate, and was analyzed theoretically by a nonisothermal technique for nucleation. As the result, it was found that differential scanning calorimetry with the constant cooling rate method is more useful in the study of the nucleation, where the parameters are given in the higher region of supersaturation ratio, compared with the constant-temperature method.
Through the theoretical analysis of nucleation, a semi-empirical relation, Eq. (1), was found to hold between the width of maximum allowable supercooling temperature, that is, the metastable zone width, ΔTm, and the cooling rate, b.
In (b/V)=In (k2/Nobs)-In B-MTTO/ΔTm2
where,
MT=16πδ3νm2/3k(ΔHsol)2
Equations (1) and (2) make the analysis of nucleation much simpler. The same nucleation data also satisfied Nývlt''s relation. However, Eqs. (1) and (2) may be more useful than Nývlt''s for the analysis of the nucleation process.View full abstractDownload PDF (407K) -
MAMORU YOSHIKAWA, KATSUSHI IWAI, SHIGEO GOTO, HIDEO TESHIMA1981 Volume 14 Issue 6 Pages 444-450
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
JOURNAL FREE ACCESSRates of mass transfer from liquid phase to small particles (average diameter, 0.46-1.3 mm) were measured by use of ion-exchange reaction followed by instantaneous irreversible reaction at 30°C. Nitrogen gas and dilute aqueous solution of sodium hydroxide were fed into a shallow bed packed with a strong cation exchange resin. Volumetric mass transfer coefficients for gasliquid cocurrent upflow and downflow were almost identical at the same gas and liquid flowrates but became somewhat greater than those in liquid-full single phase flow. A unified correlation could be derived by arranging experimental data for three arrangements: liquid-full single phase flow, gas-liquid cocurrent upflow and downflow (trickle-bed).View full abstractDownload PDF (525K) -
NOBORU SAKAI, TADASHI CHIDA, TEIRIKI TADAKI1981 Volume 14 Issue 6 Pages 450-455
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
JOURNAL FREE ACCESSEffect of sintering on the reaction rate in a gas-solid system is discussed theoretically with a mathematical model, in which it is assumed that a solid pellet consists of a large number of fine particles, and that the pellet radius becomes smaller by a factor of β than that of theoretical one owing to sintering. The model clarifies quantitatively the deceleration mechanism of overall reaction rate at the later stage due to decrease of effective diffusivity of gases in the product layer. The theoretical results using this model are compared with experimental ones for the reduction of nickel oxide pellets with hydrogen. The values of β are 0.97 to 0.67 in the temperature range of 673 to 1073 K.View full abstractDownload PDF (417K) -
SHOICHI KIMURA, YOSHIKAZU TAKAGI, SETSUJI TONE, TSUTAO OTAKE1981 Volume 14 Issue 6 Pages 456-461
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
JOURNAL FREE ACCESSAn integrated form of the rate equation for gas-solid reactions is proposed, taking into account the effect of solid structure on the reactivity of the solid. The rate equation is verified by the oxidation of iron sulfide particles, which follows the volume reaction model, with solid structure being varied due to different extent of sintering.
The rate constant based on unit particle volume takes distinct value depending on the structure of the solid phase, yielding identical apparent activation energy. The surface rate constant is then evaluated on the basis of the effective surface area for the reaction being separated from the solid structure and is correlated in an Arrhenius equation.
The proposed rate equation is approved to embrace a variety of kinetic equations used not only in the volume reaction model but in the grain model, in shrinking core kinetics, and in the gasification of a porous particle.View full abstractDownload PDF (440K) -
HIROTSUGU HATTORI, KAZUYUKI TANAKA, KUNIHIKO TAKEDA1981 Volume 14 Issue 6 Pages 462-466
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
JOURNAL FREE ACCESSIt has been found that the side-outlet spouted bed with inner draft-tube has the following advantageous characteristics stemming from the fact that simple rules hold at the beginning of spouting. When the gas velocity in the inner draft-tube increases and the ratio to terminal velocity of solid particles rises to a certain value, stable spouting begins. At the beginning of spouting the ratio of gas velocity in the gas inlet to terminal velocity of solid particles is also constant. These ratios do not change even if the size of the apparatus or the size of particles changes, as far as we have investigated on geometrically similar spouted beds. In addition, the gas streamlines are aproximately similar for geometrically similar spouted beds.
These characteristics of the side-outlet spouted bed with inner draft-tube facilitate the procedure for scale-up. For example, the minimum gas flow rate required for stable spouting can be easily predicted and the gas conversion can be easily estimated.View full abstractDownload PDF (424K) -
MOTOAKI ADACHI, KIKUO OKUYAMA, YASUO KOUSAKA1981 Volume 14 Issue 6 Pages 467-473
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
JOURNAL FREE ACCESSThe behavior of bipolarly charged aerosol particles undergoing electrostatic coagulation was studied from the theoretical and experimental points of view. The population balance equation for the behavior of the charged particles which includes the simultaneous effects of electrostatic coagulation, electrostatic diffusion and Brownian coagulation was numerically solved for aerosol particles having various initial charge distributions. As a result, the time-dependent changes in particle number concentration and charge distribution under the effects of electrostatic coagulation, electrostatic diffusion and Brownian coagulation were evaluated for various cases. Some of these results were compared with the experimental results obtained by a visual method, and were found to be in good agreement with them.View full abstractDownload PDF (542K) -
YASUSHI KAWAKAMI, HAJIME NISHIMURA1981 Volume 14 Issue 6 Pages 473-478
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
JOURNAL FREE ACCESSThe limitation of nutrient concentrations on degradation of n-hexadecane by marine Bacillus sp. was investigated by use of a semi-batch incubation system. This bacterium is a candidate organism for seeding, i.e. artificial enhancement of biodegradation of spilled oils. The degradation rate did not change greatly from 244 μmol-total inorganic N (TIN)/l and 6.5 μmol-PO4-P/l down to 4 μmol-TIN/l and 0.4 μmol-PO4-P/l, respectively. But at 2 μmol-TIN/l and 0.3 μmol-PO4-P/l, it decreased rapidly to as low as one-tenth of that with higher N and P concentrations. Both degradation rate and cell growth were approximated by the same Michaelis-Menten form equations. The concentration where the rate was reduced to half was 3 μmol-TIN/l. The nitrogen uptake rate was proportional to nitrogen concentration.
Retardation of biodegradation at the sea surface due to poor nutrient transport from underlying water was evaluated using a simple model and was shown to be small. Accordingly, the application of fertilizer is generally unnecessary in eutrophic coastal seas when this bacterium is used as seed organism.View full abstractDownload PDF (527K) -
SHINTARO FURUSAKI, TERUKATSU MIYAUCHI1981 Volume 14 Issue 6 Pages 479-484
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
JOURNAL FREE ACCESSEffect of pressure swing on diffusion in operating a membrane-immobilized enzyme reactor with pressure swing is investigated. Simultaneous effect of diffusion and pressure swing can be expressed by an enhancement factor. It can be calculated in terms of a factor ψ(=2u0/πkL), where u0 is a permeative flow rate and kLL is a film mass transfer coefficient without pressure swing. Decomposition of H2O2 by catalase was investigated with a thin film system where the diffusion effect is appreciable. Rate of decrease in H2O2 concentration agreed well with the theoretical calculations.View full abstractDownload PDF (459K) -
KATSUMI TOCHIGI, KATSUHISA UCHIDA, KAZUO KOJIMA1981 Volume 14 Issue 6 Pages 484-486
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
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HAJIME NAKAMURA, T. R. RASHAD MIYAN, SETSURO HIRAOKA, YUJI NAKAMORI, I ...1981 Volume 14 Issue 6 Pages 487-489
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
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HIROYASU OHASHI, TAKUO SUGAWARA, KEN-ICHI KIKUCHI1981 Volume 14 Issue 6 Pages 489-491
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
JOURNAL FREE ACCESSDownload PDF (228K) -
SHOICHI KIMURA, SETSUJI TONE, TSUTAO OTAKE1981 Volume 14 Issue 6 Pages 491-493
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
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YASUO HATATE, ATSUSHI IKARI, FUMIYUKI NAKASHIO, KAZUO KONDO1981 Volume 14 Issue 6 Pages 493-495
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
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EIZO SADA, SHIGEO KATOH, MASAMI SHIOZAWA, TSUNEHIKO FUKUI1981 Volume 14 Issue 6 Pages 496-497
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
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FLOW PATTERN IN A DUAL MODE AGITATOR WITH SIMULTANEOUS UP-AND-DOWN AND ROTATIONAL MOTION OF IMPELLERYASUHIRO MURAKAMI, TSUTOMU HIROSE, MASAHARU TAKAO, TSUTOMU YAMATO, HID ...1981 Volume 14 Issue 6 Pages 498-499
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
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YASUHIRO MURAKAMI, MASAHARU TAKAO, HIDEAKI INOUE1981 Volume 14 Issue 6 Pages 499-500
Published: December 20, 1981
Released on J-STAGE: April 03, 2006
JOURNAL FREE ACCESSDownload PDF (196K)
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