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RYUICHI FUKUZATO, YASUHIRO TANIGAKI, NORIAKI SHIKI, YASUSHI TOMISAKA, ...
1982 Volume 15 Issue 3 Pages
167-172
Published: June 20, 1982
Released on J-STAGE: April 04, 2006
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The constants in the modified BWR state equations for light hydrocarbons, nitrogen and hydrogen were re-determined from volumetric data selected for their even distribution over wide ranges of temperature and pressure, and the effects of the accuracy of these equations on the prediction of vapor-liquid equilibria for binary systems consisting of the above components were investigated.
It was found that the accuracy of vapor-liquid equilibrium prediction is improved greatly, even when the conventional mixing rules are used, by increasing the accuracy of the state equation for each pure component. No binary parameters in mixing rules were needed for the above binary systems, even those containing a super-critical component, if the highly improved equations of state were applied. This suggests that re-examination of the accuracy of the state equations is necessary prior to studying the effectiveness of the conventional mixing rules.
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KEISUKE FUKUI, MASAMOTO NAKAJIMA, HIROMASA UEDA, TOKURO MIZUSHINA
1982 Volume 15 Issue 3 Pages
172-180
Published: June 20, 1982
Released on J-STAGE: April 04, 2006
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For a mixed flow of free and forced convection between vertical parallel plates kept at uniform but different temperatures, the relation of the superimposed forced flow on the instability was investigated experimentally and theoretically. Experiments were performed in a duct with a large aspect ratio at Reynolds numbers ranging from 0 to 100. A flow-visualization technique was used. The result shows that the instability occurs due to a disturbance of travelling-wave type, the phase velocity being 0.855<u
*> where <u
*> is the mean velocity. The critical value of Grashof number Gr
c increases in proportion to Re
c2 and the associated wave number ac decreases gradually with increasing Re
c. The characteristics of the disturbance and their changes with Re
c were well explained on the basis of linear stability theory. In addition, the amplitudes of disturbances near the critical condition were determined from a quasi-linear approximation, and the resulting secondary flow and heat and momentum transfer processes were studied.
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AKIRA ITO, KOICHI ASANO
1982 Volume 15 Issue 3 Pages
181-187
Published: June 20, 1982
Released on J-STAGE: April 04, 2006
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The effect of condensation of mixed vapors on heat and mass transfer in binary distillation was studied theoretically and experimentally for the introduction of highly subcooled reflux below its bubble point.
A theoretical approach is made to the interfacial velocities caused by condensation of mixed vapors in contact with subcooled liquids.
Measurements of heat and mass fluxes are made for binary distillation of the methanol-water system at total reflux under subcooled conditions by a vertical flat-plate wetted-wall column and the data are compared with the prediction by laminar boundary layer theory.
On the basis of these experimental results, simulation of heat and mass transfer is made, and the results are compared with the observed data. A new method of prediction of
HTU is proposed for binary distillation under introduction of subcooled external reflux.
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NONOT SOEWARNO, KAZUMASA FUJII, HIDETO YOSHIDA, MASAHIRO YORIZANE
1982 Volume 15 Issue 3 Pages
188-193
Published: June 20, 1982
Released on J-STAGE: April 04, 2006
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Experimental studies of liquid mixing characteristics by use of a perforated tray under inclined conditions were conducted in an air-water system. The degree of liquid mixing was determined experimentally by a tracer technique to measure the distribution of residence time of the liquid. Two models are used for analysis. These models are:
1. Completely mixed pools without feedback
2. Completely mixed pools with feedback
The degree of liquid mixing is independent of the F-factor if the tray leans to the same degree.
Because of the gravitational effect and liquid velocity on the tray, the lowest degree of liquid mixing is obtained when the tray leans toward the outlet weir and highest when the tray leans toward inlet weir. By the outlet weir effect, the minimum value of degree of liquid mixing was obtained for every angle of incline.
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MASAKUNI MATSUOKA
1982 Volume 15 Issue 3 Pages
194-199
Published: June 20, 1982
Released on J-STAGE: April 04, 2006
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Phenomena of solid condensation on a cold disk were observed and the rate was measured for three organic vapors: naphthalene, p-dichlorobenzene and p-dibromobenzene. The condensation process was understood as initial nuleation followed by growth of the nuclei. The rate of condensation
N was found to include surface kinetics and was correlated successfully by the equation
N=k
aC
ia
2) where σ is non-dimensional supersaturation at the surface and is regarded as a driving force for the surface kinetics. The coefficient kσ was correlated by the Arrhenius equation with activation energy larger than the latent heat of sublimation by a factor of about 1.5.
It was considered that the surface kinetics governs the condensation rate when the mass transfer rate is very high and when it occurs at relatively low temperatures.
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SHIN-ICHI NAKAO, SHOJI KIMURA
1982 Volume 15 Issue 3 Pages
200-205
Published: June 20, 1982
Released on J-STAGE: April 04, 2006
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The friction model and the pore model were studied comparatively, and the latter was modified in order to remove the discrepancy between these two models. Ultrafiltration data of six solutes of various molecular weights, obtained in our previous study, were analyzed by this model, but the results were not satisfactory.
Wall correction factors were then eliminated from the modified pore model. The data were reanalyzed by this new model, the "steric hindrance-pore model", and it became clear that this model adequately interpreted the experimental data. The values for membrane pore radius obtained were in good agreement. The A
k/ΔX value for each solute calculated was almost constant, and agreed well with that determined from pure water permeation.
The reason why this proposed model, from which the usual wall effect is eliminated, works well is not clear at this stage.
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SON-KI IHM, SUNG-SUP SUM, IN-HWAN OH
1982 Volume 15 Issue 3 Pages
206-210
Published: June 20, 1982
Released on J-STAGE: April 04, 2006
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A model is proposed for a macroreticular resin catalyst to give the overall effectiveness factor in terms of the micro- and macro-effectiveness factors and the fraction of the surface layer active sites. Different values of the fraction can represent some possible cases of porous catalysts; i.e., a single or uniform pore and a bidisperse pore structure.
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YASUSHIGE MORI, TOSHIYA SHIOMI, NAOKI KATADA, HIROSHI MINAMIDE, KOICHI ...
1982 Volume 15 Issue 3 Pages
211-216
Published: June 20, 1982
Released on J-STAGE: April 04, 2006
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The effects of a corona precharger on the performance of a fabric filter were studied experimentally in the air with controlled humidity. Test dusts, fine calcium carbonate and fly ash, were precharged and then introduced to a test fabric. The test fabrics were felt, spun staple and filament woven fabrics.
When charged dust is collected on a test fabric at low filtration velocity and low relative humidity, a rugged surface often appears on the charged dust layer, and pressure loss across the loaded test fabric is reduced. This electrostatic effect on pressure loss occurs not only for felt fabric but also for spun staple woven fabric, but does not appear for polyester (Tetron) and glass filament woven fabrics, because of pin-hole formation.
On the other hand, the collection efficiency of a fabric filter can always be improved by using a corona precharger. The collection efficiency increases with the charge-to-mass ratio of dust. Even if pin-holes are formed during the filtration, the collection efficiency can be improved using a corona precharger, without substituting a higher-performance fabric.
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KOJI TAKAHASHI, MINORU SASAKI, KUNIO ARAI, SHOZABURO SAITO
1982 Volume 15 Issue 3 Pages
217-224
Published: June 20, 1982
Released on J-STAGE: April 04, 2006
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Mixing patterns in agitated vessels equipped with various types of helical ribbon impellers are observed by using capsules of liquid crystal as a tracer. As a result, the optimum geometrical variables for the mixing process are provided and the results explained by considering the relation between the mixing pattern and impeller geometry. A mathematical model is developed and applied in order to correlate the measure mixing times.
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OSATO MIYAWAKI, KOZO NAKAMURA, TOSHIMASA YANO
1982 Volume 15 Issue 3 Pages
224-228
Published: June 20, 1982
Released on J-STAGE: April 04, 2006
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Dynamic NAD recycling, in which native NAD, without immobilization, was dynamically recycled in continuous operation by immobilized conjugated enzymes (alcohol dehydrogenase and lactate dehydrogenase), was investigated experimentally. The results were compared with the theoretical model calculations in the preceding paper. Although there were some quantitative differences, the theoretical model could explain the experimental results at various operating conditions. Under a properly selected operating condition, a high NAD recycle number (6180) as well as a satisfactory conversion (34.6 %) of the limiting substrate was obtained experimentally. The operational stability of the present system was fairly good, retaining 70 % of its original activity after one month''s continuous operation. Compared with the immobilized-NAD method, the dynamic NAD recycling method is simple and is free from the problem of coenzyme inactivation during continuous operation. The experimental results obtained here showed the practicability of dynamic NAD recycling.
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PL. SABARATHINAM, AN. ANDIAPPAN
1982 Volume 15 Issue 3 Pages
229-231
Published: June 20, 1982
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DONG IL LEE, MOHAMED A. FAHIM, SEIICHIRO KAGUEI, NORIAKI WAKAO
1982 Volume 15 Issue 3 Pages
232-235
Published: June 20, 1982
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NOBORU SAKAI, TADASHI CHIDA, TEIRIKI TADAKI
1982 Volume 15 Issue 3 Pages
235-237
Published: June 20, 1982
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T. CHAKRABARTY, R. R. HUDGINS, P. L. SILVESTON
1982 Volume 15 Issue 3 Pages
237-239
Published: June 20, 1982
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TORAJIRO HONMA, MASAHIRO HASEGAWA, YOSHITERU KANDA
1982 Volume 15 Issue 3 Pages
240-242
Published: June 20, 1982
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MICHIHARU TOH, YASUHIRO MURAKAMI
1982 Volume 15 Issue 3 Pages
242-244
Published: June 20, 1982
Released on J-STAGE: April 04, 2006
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