All issues
Volume 8 (1982)
- Issue 6 Pages 655-
- Issue 5 Pages 545-
- Issue 4 Pages 327-
- Issue 3 Pages 219-
- Issue 2 Pages 109-
- Issue 1 Pages 1-
Predecessor
Volume 8, Issue 3
Displaying 1-14 of 14 articles from this issue
- |<
- <
- 1
- >
- >|
-
Hiroyuki Hatano, Masaru Ishida1982 Volume 8 Issue 3 Pages 219-224
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSA method for measuring continuously the local concentration in three-dimensional equipment is proposed. This method, in which a fine optical fiber probe was used, is based on the absorptiometry technique.
The measurement of concentrations of blue ink in water, NO2 gas in air, and fine kaolin powder suspended in water showed its high applicability.
It was also used to measure the tracer gas concentration in a gas-solid fluidized bed. It was found that the tracer concentration was continuously measured not only in the bubble phase but also in the emulsion phase with high-speed response.View full abstractDownload PDF (816K) -
Tadashi Iguchi1982 Volume 8 Issue 3 Pages 225-231
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSAn experiment was performed to investigate the carryover flow rate from a liquid pool above an orifice plate through which a vertical air flow was maintained. Based upon visual observations, the major causes of the carryover phenomena were classified into three types : (1) entrainment generated by the breaking of a bubble at the surface of the liquid pool; (2) entrainment generated by the disintegration of a large-amplitude wave or bridge near the water surface; and (3) carryover by vertical oscillations of the water surface. It was found that the carryover rate is governed mainly by phenomena near the surface and partially by the geometry of the inlet orifice. To predict the type (2) carryover rate, a non-dimensional correlation was derived on the basis of a momentum exchange assumption.View full abstractDownload PDF (965K) -
Mompei Shirato, Toshiro Murase, Masashi Iwata1982 Volume 8 Issue 3 Pages 232-239
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSSimplified methods for analysing the pressure profile of Bingham fluids in screw extruders are presented. The conventional flow equation for Bingham fluids is modified in definition of an average differential viscosity. Simplified equations for predicting the pressure distribution in the extruders of both constant pitch-straight taper type and constant channel depth-varying pitch type are derived on the flat-plates representations of the screw channel, in consideration of the fact that the leakage comprises both pressure flow and drag flow components at right angles to the helix. Graphical evaluation of a correction factor for better approximation of the differential viscosity is shown by calculating the rates of pressure flow from the Mori-Ototake's equation. Empirical equations of shape factors for the flat-plates model are also presented by computing velocity profiles in rectangular flow area from the maximum principle of Bingham fluids. It is shown that the pressure profiles along the screw channel and the screw characteristics can be easily estimated in ways similar to those for extrusions of Newtonian and power law fluids.
Estimated values showed good agreement with the experimental results obtained from the screw extrusion of Bingham, fluids, under the conditions where Bingham number NB ranges up to 16.6.View full abstractDownload PDF (1202K) -
Osamu Kuroda, Harumi Matsuzaki, Sankichi Takahashi1982 Volume 8 Issue 3 Pages 240-245
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSIn this study, a bubble cleaning-type electro dialyzer was developed. In this device, air bubbles act as turbulence promoter and cleaner for membrane fouling. The mass transfer promoting effects of bubbles was investigated with rectangular channels having a narrow clearance of 15 mm, which corresponds to compartments of an electrodialyzer. Mass transfer coefficients kL, were obtained by means of an electrochemical reaction of the redox system.
It was confirmed that bubble agitation is highly effective on the grounds that kL, is increased by five to ten times by bubbling, and the effect of bubbling extends fairly uniformly along the channel. In comparison with the effect of net-type spacers used in the conventional electrodialyzer, bubbles exhibited equal ability at low flow rate of solution and at low pressure drop. From these results, it becomes clear that the structure of the bubble cleaning-type electrodialyzer is simplified and that once-through treatment can be realized with this device.
Furthermore, experimental formulas which express the relation between JD factor of mass transfer and friction factor were obtained under the conditions of bubble agitation and spacer insertion. A correlation between kL and bubble rising velocity was also determined.View full abstractDownload PDF (1100K) -
Satoru Kato, Hikoji Inazumi, Takanori Suzuki1982 Volume 8 Issue 3 Pages 246-253
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSMass transfer rates of two diffusive components in ternary gas systems were investigated experimentally on the basis of the Stefan-Maxwell equation.
The values of effective diffusion distances defined by a film model were checked with experimental data and it was confirmed that the values are given by a function of the flow conditions and the kind of system.
Further, a method of estimation of mass transfer rates was proposed, and its applicability was ascertained with experimental data.
The effects on mass transfer rates of diffusion between the two diffusive components contained in a ternary system were investigated on the basis of experimental data. As a result, it was confirmed that diffusions between the two diffusive components were the controlling factor under conditions where the peculiarity of mass transfer in the ternary systems is particularly notable.View full abstractDownload PDF (1158K) -
Takeichiro Takamatsu, Iori Hashimoto, Kenji Kawachi, Kenzo Yamashita1982 Volume 8 Issue 3 Pages 254-260
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSWhen designing the decoupling control system of a multi-component distillation column by using state variable feedback, the number of state variables to be fedback increases according to the number of components.
To overcome the above short-coming, it is proposed in this paper to design the decoupling control system with a pseudo binary model. It was found that the pseudo binary model obtained from only two key-components does not give a satisfactory result for the decoupling control system design. Then a new pseudo binary model was derived by providing the direction of the composition change around the steady-state condition.
It is confirmed that the decoupling control system designed by use of this pseudo binary model has almost the same performance as that designed by use of the multi-component model.View full abstractDownload PDF (841K) -
Yoshiharu Murata, Hiroshi Yamakawa, Yasunobu Kawakami, Shigeru Okumoto ...1982 Volume 8 Issue 3 Pages 261-265
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSSecondary nuclei were generated by a parent crystal suspended in an agitated solution of CuSO45H2O and KAl (SO4) 212H2O, and the changes of population density and number frequency distribution with elapsed time were observed by Coulter Counter. The following results were obtained.
1) In a supersaturated solution, a decrease of population density of generated nuclei was observed at the beginning of elapsed time. The decreasing rate of particles was recognized to depend on the relative supersaturation.
2) Shape of the cumulative curve for both systems changed with elapsed time. The change for CuSO45H2O depends on the presence of particles which have a lower growth rate than average. By contrast, the change for KAl (SO4) 212H2O depends on the presence of particles which have a faster growth rate.
3) Minimum particle size for the birth of secondary nuclei was confirmedView full abstractDownload PDF (845K) -
Tadaatsu Ido, Takayoshi Tsuzuki, Shigeo Goto, Hideo Teshima1982 Volume 8 Issue 3 Pages 266-272
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThree kinds of butene isomers were fed into a fixed-bed reactor packed with Al2O3 or MoO3 on Al2O3. The isomerization of butene took place over both catalysts and the variations of the rate with time due to coke formation could be expressed by a dual-site decay reaction. The decay rate constants were almost independent of kinds of catalysts and butene isomers at the inlet. The disproportionation of butene did not cocur over Al2O3. However, when MoO3 on Al2O3 was used, mainly propylene and pentene were produced by the disproportionation reaction. This might be due to the enhancement of the shift reaction of double bond between 2-butene and 1-butene by MoO3. The variation of disproportionation rate with time could be represented by a single-site decay reaction, which was different from that of isomerization.View full abstractDownload PDF (1015K) -
Mitsutaka Kitamura, Tasuku Nakai1982 Volume 8 Issue 3 Pages 273-278
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThe composition of clathrate crystals containing tetra (4-methylpyridine) nickel (II) thiocyanate and p-xylene are affected mainly by solution composition and crystallizing temperature. The dependence of crystal composition on two operating factors were investigated by the differential crystallization method.
In this case, both the liquid p-xylene clathrate produced by the reaction of p-xylene and Ni-complex, and the liquid solvent clathrate produced by the reaction of (methylcellosolve+4-methylpyridine) mixture used as solvent and Ni-complex, were assumed to be present in the solution. Therefore, the composition of crystals precipitated in such a solution should be determined by the relative crystallization rate of both clathrates.
Using this crystallization model, a semiempirical equation representing crystal composition as a function of solution composition was derived. Since a parameter corresponding to the solubility of p-xylene clathrate in solution was introduced in this equation, crystal compositions could be expressed as a function of the degree of supersaturation of p-xylene clathrate.
It was confirmed that crystal compositions calculated by the equation approximately coincide with data obtained for differential crystallization at solution temperatures of 20, 30 and 40°C.View full abstractDownload PDF (803K) -
-On the effect of pressure-Katsuhide Murata, Kenji Sato, Hideo Teshima1982 Volume 8 Issue 3 Pages 279-284
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThermal degradation of high-density polyethylene was carreied out by use of a CSTR under pressures of 1-8 atm at 440°C to study the effect of pressure on the thermal degradation of polymers.
The following results were obtained.
1) The pressure has a striking effect on the degradation rate of polyethylene. The degradation rate decreases to half with the elevation of pressure 1-8 atm.
2) The molecular weight of gaseous product, liquid product and reactor contents decrease with the elevation of degradation pressure.
3) The elevation of pressure decreases the foaming phenomena in the reactor and makes the operation more stable.View full abstractDownload PDF (816K) -
Jiro Koga, Shigehisa Endoh, Masunori Sugimoto, Kenji Yamaguchi1982 Volume 8 Issue 3 Pages 285-290
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSAn inclined rotating disc with a spiral scraper was used to separate spherical particles from a mixture containing non-spherical particles. Shape analysis was applied to the separated particles. The shape indices adopted in this study were the ratio of equivalent and representative diameter. The Fourier discriptors of particle peripheries were also used. Newton's separation efficiency, considering the information on shape, was proposed and studied. The results show that the separation efficiency was changed by the values of shape indices.View full abstractDownload PDF (3283K) -
Kunihisa Ohsasa, Masao Sambuichi, Hideo Nakakura, Takashi Shibuya1982 Volume 8 Issue 3 Pages 291-297
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThe relation among the initial settling rate in a tilted rectangular tube, υi0, the angle of inclination from vertical axis, θ, the face spacing, b, and the initial slurry height, ho, in the vertical direction was examined experimentally with four kinds of slurries, such as ground limestone-water and kaolin-water. It was found that the settling enhancement factor, the ratio of υi0 to the settling rate in a vertical tube υ0, was proportional to sinθ, h0, and inversely proportional to b. The equation for predicting the settling enhancement factor was presented from the mass balance on supernatant by defining the average flow rate of supply of clear liquid based on unit horizontal projected area of the downward facing plate, L. The values of L calculated by the equation were expressed a function of υ0 alone within ±30% average error. Calculated values agreed approximately with experimental values obtained from measurement of the flow rate of clear liquid under the downward facing plate using fine, colored polystyrene particles as a tracer.View full abstractDownload PDF (1086K) -
-Effects of mean molecular weight of flocculant and suspended particle size-Shuji Sakohara, Hajime Unno, Takashi Akehata1982 Volume 8 Issue 3 Pages 298-303
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThe effects of mean molecular weight of flocculant and suspended particle size on turbidity removal of kaolin suspension by nonionic polyacrylamide were experimentally clarified and studied in terms of the amount of flocculant adsorbed to the surface of suspended particles.
The ratio of amount of flocculant absorbed to its dosage depends on flocculant mean molecular weight. This ratio decreases with decrease of mean molecular weight. Turbidity removal from suspensions of particles of the same specific surface area by flocculant of greater than three million is determined by the amount of flocculant adsorbed.
In the case of a suspension of particles larger than the flocculant molecule, the ratio of amount of flocculant adsorbed to its dosage is smaller than that in the case of a suspension of particles of a size of the same order as the flocculant molecule. When the most effective turbidity removal is achieved the amount of flocculant adsorbed is constant, irrespective of particle size, as long as total particle surface area of each suspension is equal.
These results indicate that the turbidity removal from a suspension by a polymeric flocculant is determined by the coverage of particle surface by the flocculant molecules.View full abstractDownload PDF (1080K) -
Toshiro Miyahara, Megumu Tanimoto, Teruo Takahashi, Kanichi Suzuki, Ry ...1982 Volume 8 Issue 3 Pages 304-326
Published: May 10, 1982
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSDownload PDF (5095K)
- |<
- <
- 1
- >
- >|