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Volume 9 (1983)
- Issue 6 Pages 603-
- Issue 5 Pages 477-
- Issue 4 Pages 353-
- Issue 3 Pages 233-
- Issue 2 Pages 111-
- Issue 1 Pages 1-
Predecessor
Volume 9, Issue 3
Displaying 1-17 of 17 articles from this issue
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Akira Kurata, Hideki Yamamoto, Masao Obata, Seiji Sanga1983 Volume 9 Issue 3 Pages 233-236
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe specific heats of NH4Br-NH3 and NH4I-NH3 systems were measured in a range of concentrations from 10wt% to 70wt% at 25°C.
For the measurements, a twin calorimeter consisting of two metallic Dewar cells of the same size was employed at high pressure (3-13×105Pa).View full abstractDownload PDF (554K) -
Katsuji Noda, Yoshiaki Aono, Kiyoharu Ishida1983 Volume 9 Issue 3 Pages 237-240
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSViscosity and density at 298.15K were measured for ternary ethanol-acetic acid-water system and binary mixtures of its constituents.
A five-body interaction model equation is derived by the present authors from analogy with the three- or four-body interaction model of McAllister. The viscosity data obtained are correlated satisfactorily by this equation.View full abstractDownload PDF (477K) -
Chikao Arai, Yasunori Wakabayashi, Akira Mizuno, Ichiro Komatsu, Yoshi ...1983 Volume 9 Issue 3 Pages 241-244
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSRelative humidities lower than about fifty percent were measured by use of saturated aqueous solutions of certain inorganic salts in the range of 10° to 50°C.
In some cases, a hydrate salt existing in solid phase converts to a lower hydrate salt at a given temperature. Discontinuous changes of relative humidity were shown near this transition point.
Furthermore, it was found that there was a very small difference of relative humidities between pure and impure salts. We concluded that pure salt was not necessary for humidity control only, but that cheaper impure salt was enough.View full abstractDownload PDF (737K) -
Katsuo Komori, Akira Iguchi, Ryotaro Izumi1983 Volume 9 Issue 3 Pages 245-250
Published: May 10, 1983
Released on J-STAGE: July 27, 2010
JOURNAL FREE ACCESSThe characteristics of turbulent flow in divergent channels of rectangular section with comparatively small angle were experimentally investigated. The results were as follows:
The velocity profiles were recognized as a composite structure consisting of those in the inner and outer layers. The inner layer was the region where the law of the wall could be applied independently of adverse pressure gradient. Its region decreased with increasing longitudinal distance x. The outer layer was the region which formed a plane jet relatively uninfluenced by the divergent walls.
The effectiveness of Coles'law of the wake was confirmed qualitatively, but the maximum deviation from present experimental data was from 10 to 20%.
The skin-friction profiles with distance were classified into three patterns of variation in the downstream direction, and could be expressed by the relation of Reynolds number Reθ and shape factor H in the region where skin-friction coefficients decreased in the x-direction.
The initial state of separation occurred at a divergence of 8°, and the region of back flow was limited very near the wall. Phenomena such as reattachment were observed at divergent angles of more than 4°.View full abstractDownload PDF (1097K) -
Tatsuo Tokimasa, Yoichi Nagase, Syoichi Murakami1983 Volume 9 Issue 3 Pages 251-256
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSHydrodynamic interaction reported in this paper was initiated in experiments on two-dimensional vortical motion which was produced in transition of the two-stream mixing layer. The mixing layer was developing non-lineally and the boundary layer on the side wall, which was perpendicular to the mixing layer, was laminar at the origin of the mixing layer. The phenomenon was that the interface between the two boundary layers of high and low streams was at first excited by the vortical motion in a roll-up type. This disturbance was quickly developed at the interface and also was propagated into the boundary layer of high-stream side. The disturbances at the interface and in the high-stream side coincided to form a large and coherent vortical motion of which both tails lay longitudinally in the boundary layer of the high-stream side, and the central part elongated into vortical motion of the mixing layer. This elongated one could be recognized as the “inflow” pointed out by Browand. Both inflows developed from side walls pushed the mixing layer toward its center line. Then the mixing layer in the duct center was skewed to be a partial pairing. Two-dimensional vortical motion was broken down to turbulence after the partial pairing progressed abruptly over the full span of the duct.View full abstractDownload PDF (3172K) -
A part of inner cylinder is heatedTamotsu Hanzawa, Kunio Kato1983 Volume 9 Issue 3 Pages 257-262
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe effect of natural convection upon the flow pattern was investigated in the closed annular cavity formed by two concentric vertical cylinders with a part of the inner cylinder heated. From observation of the streamline in the cavity by a smoke tracer, fundamental equations are solved numerically. Steady-state isothermals and streamlines are obtained for Grashof numbers up to 2×107 and for various lengths of heating zone.
To check the calculated results, temperature distributions are measured in this cavity. The calculated temperatures are a good approximation of the experimental ones and the calculated Nusselt number is compatible with some previous theoretical and experimental results.View full abstractDownload PDF (2597K) -
Hajime Ino, Nobuyuki Imaishi, Mitsunori Hozawa, Katsuhiko Fujinawa1983 Volume 9 Issue 3 Pages 263-269
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe bottleneck of W/O/W emulsion extraction seems to lie in its final stage, i. e. the breaking of W/O emulsion (demulsification). This work was undertaken to ascertain the feasibility of the AC electrical method for the demulsification and to clarify the fundamental characteristics of the method.
The W/O emulsions used were made from an aqueous solution of NaCl and kerosene, dissolving 4 vol% of Span 80 with a rotary disperser. The average diameters of the dispersed water droplets, dp, were in the range of 3.2-4.7μm. The emulsions were found to be stable in both a centrifugal demulsification test and a thermal one. The applications of AC potential of 1-12kV, between a nonconductive electrode of glass in the emulsion layer and the underlying water layer, caused a marked decrease in emulsion stability, and a clear water layer was formed. The throughput rates V of the clear water were expressed as
where H is the distance between electrodes, E the applied AC potential, μ the viscosity of the emulsion, μc the viscosity of the oil phase and ET the transition potential, which is in the range of 6-8kV.
In conclusion, the W/O emulsion can be broken by the AC electrical method, provided that the diameter of the water droplets is larger than 1μm.View full abstractDownload PDF (1218K) -
Kenkichi Izumi, Akira Yamada, Toshimi Mukushi, Sankichi Takahashi1983 Volume 9 Issue 3 Pages 270-276
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSA pair of 2000-hr long-running tests for scale prevention in a 100-m3/d, 10-stage flash evaporation type desalination plant were carried out. From the result of the first test on pH control, it was shown that the formation of alkaline scale was effectively prevented but the performance ratio of the plant was lowered by iron sludge deposition on the surface of the heat transfer tubes in the plant. In a brine heater, calcium sulfate scale was formed. The fouling substance in the brine heater had a two-layer structure, an iron sludge layer and a calcium sulfate layer. Consequently, it was found that deposition of rion sludge induced the precipitation of calcium sulfate.
From the variation of fouling factor with time in the first test, it was presumed that formation of the foulant was divided into three steps: 1) deposition of sludges, 2) formation of nuclei of calcium sulfate, and 3) growth of sulfate scale.
pH control combined with sponge ball cleaning, which was an effective method of sludge removal was examined as the second test. The test results showed successful prevention of formation of scales and sludges.View full abstractDownload PDF (1263K) -
Estimation of an over-all mass transfer coefficient for dialysis in the case that osmotic flow of water is taken account ofSatoshi Yumoto, Haruhiko Ohya1983 Volume 9 Issue 3 Pages 277-282
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSDialysis experiments were carried out using a dialyzer with capillary membranes. It was found that the over-all mass transfer coefficient for dialysis U0 decreased with increasing inside flow rate of membrane qIN in the region above 7ml/min. This phenomenon could be explained by the mechanism of a solute and water transport across a membrane which became clear by deriving a diffusion equa ion of Maxwell-Stephan type taking account of the osmotic flow of water.
Mass transfer coefficients in diffusion films obtained by the method of velocity variation were compared with those of the usual correlations. An almost linear concentration distribution was calculated by the mass transfer coefficients and the osmotic flow of water.
Comparing the water or salt permeability of the used dialysis membrane with that of a typical cellulose acetate reverse osmosis membrane, respectively, it was found that the water permeability of the dialysis membrane was much smaller than that of a cellulose acetate membrane.
The relationship between U0 and qIN for some electrolytes could be estimated from that of U0 vs. qIN for sodium chloride.View full abstractDownload PDF (1033K) -
Haruhiko Ohya, Junichi Taga, Yoichi Negishi1983 Volume 9 Issue 3 Pages 283-288
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSReverse osmotic concentration of aqueous iso-propyl alcohol solutions was carried out using cellulose acetate membrane (CA) and composite membranes (PEC and NS-100). Separation of isopropyl alcohol and flux through the membranes were measured under the following conditions: concentration of isolpropy alcohol: 1, 2.5, 5, 10 and 15 wt%, operating pressures: 2, 4 and 6PMa. The most favorable separation and flux obtained under the conditions of lower concentration and higher operating pressure were (ca. 60, 0.3), (99.6, 0.25), and (99, 0.3) (%, mol·m-2s-1) for CA, PEC and NS-100, respectively.
An analysis has been made of the data by the Spiegler-Kedem transport model. The values of reflection coefficient σ were 0.64, 1.0 and 1.0 for CA, PEC and NS-100, respectively. The values of solute permeability w were 3.82×10-10, 1.14×10-11 and 2.36×10-11 mol/ (mm2Pa·s) for CA, PEC and NS-100, respectively. Flux is expressed as follows:
Jv=Lp0exp (-αΔP-βπ (c2)) (Δp-Δσπ)
where βs are 0.325, 0.344 and 0.441 for CA, PEC and NS-100, respectively.
Calculated permeation flux coincides well with measured data but calculated separations do not in the region of higher concentration.View full abstractDownload PDF (953K) -
Hiroyuki Kawasaki, Hisaya Tanaka1983 Volume 9 Issue 3 Pages 289-294
Published: May 10, 1983
Released on J-STAGE: July 27, 2010
JOURNAL FREE ACCESSAir-water upward cocurrent flow in packed beds was investigated in a 0.1m-i. d. column packed with spheres and cylinders. The hydraulic radius model was used to analyze the average gas holdup φ of the gas-liquid two-phase flow.
According to the results obtained in a vertical pipe, φ was standardized by the reference quantity β, which was the ratio of volumetric gas flow rate to the sum of volumetric gas and liquid flow rates. The φ/β was correlated by the flow parameter Fp, which was the ratio of the magnitude of a single bubble free-rising velocity to that of the forced one for the case of negligible gas-liquid relative velocity.
From this analysis, it is recognized that Fp is the dynamic characteristic parameter determined by the reference quentities (ug0+ul0) /ε and (σ/Δρg) 1/2 in gas-liquid upward cocurrent flow, since it represents the relative magnitude of several forces in the flow field.View full abstractDownload PDF (925K) -
Takeshi Takahashi, Akira Kanagawa1983 Volume 9 Issue 3 Pages 295-301
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe charging of aerosol particles by bipolar ions in a radioactive Am-241 charge neutralizer and in a stream following the neutralizer were studied theoretically and experimentally.
The charge distribution of aerosol particles attained by the neutralizer agrees well with Gunn's equilibrium charge distribution with γ-/γ+=1.1, where γ+ and γ- represent the positive and negative ion conductivities, respectively.
Although the mean value of particle charges in the aerosol stream from the neutralizer changes from negative to positive with increasing distance from the neutralizer, the equilibrium charge distribution still holds good. The experimental results are explained by theoretical calculations based on the birth-death stochastic equations, using the attachment coefficient of ions given by Bricard.View full abstractDownload PDF (1320K) -
Mompei Shirato, Toshiro Murase, Masashi Iwata, Niichi Hayashi, Hiroshi ...1983 Volume 9 Issue 3 Pages 302-308
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe continuous dewatering mechanism of slurry materials in a screw press is analysed by the flat-plates representation of the worm channel, and a method for predicting screw expression performance at steady state is presented in this paper.
Screw expression of slurry consists of two types of dewatering mechanisms. These mechanisms are analysed first by using the variable pressure-variable rate filtration theory and second by the similar consolidation theory for batch operations. The continuous expression equations for relating dehydration rate to feed rate and expression pressure distribution are derived for constant pitch-straight taper type screws, on the assumption that screw expression is a continuous succession of batchwise processes. Under the conditions of known feed rate and expression pressure profile, the solid concentration and flow rate of compressed cake discharged from the unit is evaluated by computing both the distributions of filter-cake thickness and the volumetric flow rate of consolidated cake on the basis of compression permeability data. It is shown that the critical rotating speed, where the feed slurry begins to be highly deliquored, is heavily dependent on external diameter and helix angle of the worm.
Experimental data obtained by the screw expression of clay slurries with feed concentration sF of 0.31-0.46 were in good agreement with the predictions.View full abstractDownload PDF (1214K) -
Daisuke Konno, Naozumi Okita1983 Volume 9 Issue 3 Pages 309-315
Published: May 10, 1983
Released on J-STAGE: July 27, 2010
JOURNAL FREE ACCESSSide-entering mixers are used for blending and for preventing sludge sediments in largecapacity tanks.
There has been some reserach into power consumption and blending time of mixers, but only for a constant insert angle.
Furthermore, there have been almost no investigations or experimental data on sedimental accumulation.
The main purpose of this report is to study the phenomena of sedimentation by sideentering mixing.
In the model test with spherical particle, the side-entering mixer was set at an angle of 10 degrees as viewed from the top of the tank.
The particle sedimentation area and changes of flow pattern were observed and measured.
Following the pilot test, site measurements were taken of sedimentation in a crude oil storage tank.
This study makes clear the relation between the equation of the cleaning area and the conditions of sedimentation in side-entering mixing.View full abstractDownload PDF (4982K) -
Fumihide Shiraishi, Koei Kawakami, Keiichi Kato, Koichiro Kusunoki1983 Volume 9 Issue 3 Pages 316-323
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSTo evaluate the effectiveness of a ceramic monolith (mean pore diameter 15μm) as a support for the immobilized enzyme that catalyzes the hydrolysis of a high-molecular weight substrate, the hydrolysis of soluble starch (average molecular weight, 30000) by use of glucoamylase from Rhizopus delemar was carried out at 50°C, pH 4.5.
By observing the initial reaction rate in a batch reactor, wherein a fan-shaped piece of the immobilized enzyme monolith was fixed around a stirrer shaft, the pore diffusion resistance was found to be negligible when the concentration of starch exceeds 89g/l.
The simplified kinetic model, previously proposed, that assumed kinetic parameters as changing linearly with reduction of average molecular weight of substrate was also useful for simulating the immobilized enzyme system, regardless of batch or continuous mode, described in this paper.View full abstractDownload PDF (2884K) -
Hiroyuki Kawashima, Motoyuki Suzuki1983 Volume 9 Issue 3 Pages 324-329
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSLarge quantities of attached algae grow in shallow urban rivers that receive nutrientenriched effluent from secondary sewage treatment plants. Deterioration of water quality caused by respiration and detachment of attached algae is observed in these rivers.
The kinetics of growth and detachment of attached algae in a circulation-type artificial river are studied in order to determine parameters involved in a water-quality simulation model of shallow and polluted rivers.
First-order rate constant of algal detachment was found to increase with aging of attached algal community. And on the basis of the fact that only this surface layer of attached algal community (about 0.2g chlorophyll-a/mm2) receives sufficient light for growth, a kinetic model for the growth and detachment of attached algae is defined.View full abstractDownload PDF (1234K) -
Tetsuya Kohya, Ikuo Goto, Eiji Harada, Masayuki Toda, Hirotaka Konno, ...1983 Volume 9 Issue 3 Pages 330-351
Published: May 10, 1983
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSDownload PDF (4677K)
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