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Masanori Fujitsu, Sachio Sugiyama
1982 Volume 8 Issue 5 Pages
545-551
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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A theoretical analysis to make clear the fracture mechanism of virgin castables during initial heating is performed by the finite element method based on the plane strain model. Comparisons of the calculated results with experimental data for a hollow cylindrical sample without free water resulted in the following findings :
1) The crack detected at the outer surface seemed to result from propagation of the crack which breaks out in the neighborhood of the inner sample surface.
2) Comparisons of the results of this investigation with past studies by the author
et al. showed the same conclusion as the established theory that virgin castables fracture more easily during initial heating than do castables during heating up after the initial heating. The effect of the dehydration reaction of cement hydrate seemed to be negligiblly small in this investigation range.
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Takayuki Iguchi, Satoshi Okuda
1982 Volume 8 Issue 5 Pages
552-555
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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For exact analysis of liquid diffusion into organic linings, the concentration distribution of liquid in the lining was taken into consideration in the calculation of electrical capacitance of the lining, which is increased by liquid diffusion. The results were compared with those obtained in the case of uniform liquid distribution and with the experimental results.
The resistance method to determine the diffusion coefficients was applied to the case in which the decrease in electrical resistance of resin caused by liquid diffusion is relatively small. In this case, the resistance calculation neglecting the electrical resistance of resin without diffusion would have given too crude a result.
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Takayuki Iguchi, Satoshi Okuda
1982 Volume 8 Issue 5 Pages
556-559
Published: September 10, 1982
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The degradation process of organic linings where a temperature differential existed was investigated by the application of electrical capacitance measurements. More extensive blistering occurred on linings exposed to hot water on one side and another metallic substrate was kept to a lower temperature. In this case, a large increase in capacitance was measured. This increase of capacitance was due to the penetration of liquid. The liquid diffusion process in linings under a temperature gradient was expressed by introducing the term of thermal diffusion. It was found that thermal diffusion played an important part in degradation of linings under a temperature gradient.
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Hitoshi Takase, Hajime Unno, Takashi Akehata
1982 Volume 8 Issue 5 Pages
560-565
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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The power consumption of a disk turbine-type impeller of six blades in a surface aeration tank with square cross-section was examined experimentally in terms of tank and impeller sizes, impeller speed, impeller submergence and liquid depth. The relationship between the power number and the variables was examined through the knowledge of liquid flow pattern observed by a flow visualization method.
When there was no air entrainment under the impeller, the power number was a constant depending on the apparatus geometry. But when any air entrainment appeared under the impeller, the power number decreased proportionally to (impeller Reynolds number)
-1.0.
In the case where an axial liquid flow was dominant, the value of the power number became constant, but in the case where a circular flow was prevailing, it decreased with the ratio of liquid depth to tank width.
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Kiyotaka Sakai, Makio Tamura, Atsushi Ishikawa, Masaki Komori, Kazuhir ...
1982 Volume 8 Issue 5 Pages
566-571
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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Although the submerged combustion apparatus has a very high thermal efficiency, the pressure drop is not small. Therefore, a new haet exchanger with direct contact of combustion gas and liquid using spray quenching has been developed for the reduction of this high pressure drop. It was found to be possible to maintain a very high thermal efficiency with 1/10 of the usual pressure drop. The effect of mixing on the volumetric heat transfer coefficient was influenced by the number and diameter of supplied water tubes. The empirical equation for the volumetric heat transfer coefficient was obtained from experimental data.
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Toshikuni Yonemoto, Mutsuo Narita, Tsuneyuki Sato, Teiriki Tadaki
1982 Volume 8 Issue 5 Pages
572-577
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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An experimental and a theoretical study were performed on the chemical absorption of NH
3 or SO
2 in a wetted-wall column. It was found that the force induced by mass flux acts to compress the stream lines toward the liquid film and to promote gas absorption.
When these phenomena are significant, great difficulty may be encountered in a quantitative evaluation of the absorption process by experiments alone, owing to the change of total flow rate and the existence of density convection due to the density distribution.
Considering the variation of physical properties and the change of flow rate, the momentum and diffusion equations were solved by the finite difference technique. The results can also express the absorption processes quantitatively at high mass transfer condition.
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Katsuyuki Kubota, Shinya Hayashi, Kazuki Tawa
1982 Volume 8 Issue 5 Pages
578-583
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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Monovalent cationic ions, Na
+, and NH
4+, were separated experimentally from their aqueous solutions using a familiar anionic surfactant, sodium dodecylbenzenesulfonate, DBSNa, as a collector.
In this experiment, surface excesses of DBS
- increased monotonically with increases of colligend ions concentrations.
An equation for predicting the surface excess of the collector ion, DBS
-, obtained by combining an adsorption isotherm of DBS
- for the aqueous DBSNa solutions and the surface potentials, was applied and studied for aqueous DBSNa solutions containing Na
+ and NH
4+.
The surface excesses of Na
+ and NH
4+, just compensating the negative chavged surface originating from the adsorption of DBS
-, were calculated by using the predicted surface excesses of DBS
- and the diffuse layer theory in which the surface excesses ratio of these colligend ions should be the same as their concentrations in the bulk liquid. The calculated surface excesses were well supported qualitatively by the experimental foam separation data.
Zeta-potentials in the slipping-plane between the fixed negatively charged bubble surface film originating from the adsorption of DBS
- and flowing liquid were measured for the aqueous DBSNa solutions using the Dorn effect, and it was found that the surface potentials and the zeta-potentials were compatible in numerical values.
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Hideto Yoshida, Nonot Soewarno, Kazumasa Fujii, Masahiro Yorizane
1982 Volume 8 Issue 5 Pages
584-589
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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Experimental and theoretical studies of the effect of liquid mixing of tray and downcomer for an inclined perforated tray were conducted. It is found that the degree of liquid mixing becomes least when four baffles whose height is about that of the outlet weir are installed at equal distances. To reduce the degree of liquid mixing change, it is desirable to install baffles. The value of mixing degree on the tray becomes greatest when the tray is inclined to the inlet weir side and least when the tray is inclined to the outlet weir side. The change of liquid velocity makes the difference of mixing degree on the tray. The degree of liquid mixing in the downcomer is nearly equal to that of the tray; it becomes greatest when the tray is inclined to the outlet weir side and least when the tray is inclined to the inlet weir side. This trend is opposite to that of mixing on the tray.
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Kohei Ninomiya, Atsushi Kuribayashi, Hisashi Kono
1982 Volume 8 Issue 5 Pages
590-597
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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Absorption reactions of NO and NO
2 mixture gas (NO
x) in aqueous NaOH solutions were investigated, using a stirred cell. Based on these experimental results, models of the absorption of NO
x gas are presented considering the diffusion rate of NaOH. For the case of high diffusion rate of NaOH, the results could be satisfactorily interpreted, on the basis of a theory of absorption with non-instantaneous, irreversible first-order reactions of N
2O
3 and N
2O
4. For the case of low diffusion rate of NaOH, the results could be interpreted by the model with a reaction of HNO
2 to N
2O
3 as well as the hydrolysis of N
2O
3 and N
2O
4, considering a reaction plane in the liquid film.
The selectivity of NO
3- was greatly increased with a decrease in concentration of NaOH, and these results were explained by the proposed absorption mechanism.
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Tsutao Otake, Setsuji Tone, Isao Komasawa, Masao Kawashima
1982 Volume 8 Issue 5 Pages
598-603
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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Using a well-mixed annular cylindrical reactor with a light source along its center line, the photochemical decomposition of potassium ferro- and ferricyanides was carried out over a wide range of concentrations of the reactants and their intermediates. The light intensity profile during decomposition was evaluated on the basis of the simple radial light model, and the decomposition rates were then analysed. An overall rate expression for the decomposition was obtained, taking into account a light intensity profile during the process in the reactor.
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Yutaka Hasegawa, Daizo Kunii
1982 Volume 8 Issue 5 Pages
604-610
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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Composite pellets of fine iron are and heavy oil (0.2 kg-oil/kg-ore, mean diameter 773 μ) and inert solids (mean diameter 356, u) were fed into a fluidized bed continuously, and the composition of the gaseous products and the degree of reduction of the overflow pellets were determined. The temperature of the bed ranged from 850 to 1, 050°C. The holdup of the pellets employed was from 5 to 20%, and the mean residence time of the pellets was from 10to 80 minutes.
The effects of holdup and mean residence time on the degree of reduction were investigated, and the results of the present work were compared with those of previous work with single pellets. These investigations and comparisons showed that decomposition of methane, gasification of carbon deposited on inert solids and reduction of pellets pre-reduced by heavy oil took place in the fluidized bed.
Moreover, it was found that agglomerates were produced to choke the bed in the case of high bed temperature (above 950°C), large holdup (above 20%) and long mean residence time (above 80 min).
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Masanobu Hasatani, Megumu Yuzawa, Kouji Ogura, Hitoki Matsuda
1982 Volume 8 Issue 5 Pages
611-617
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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Using the sulfated iron FeS
α formed by sulfurization of Fe
2O
3 with H
2S, reactivity of FeS
α with O
2 was investigated experimentally in a thermogravimetric analyzer (TGA) in order to demonstrate the practical feasibility of desulfurization using the Fe
2O
3-Fe-FeS
α reaction cycle. A summary of the results obtained under the conditions employed :
1) FeS
α is almost perfectly converted into original Fe
2O
3 above 600°C independently of oxygen concentrations and particle sizes. Below 600°C, however, the conversion to Fe
2O
3 is imperfect owing to the difference of reaction scheme. Furthermore, assuming the apparent single-stage reaction of first order with respect to O
2 concentration, the rate expression is examined on the basis of a grain model. The value of activation energy thus obtained is 25.6 kJ/mol.
2) Fe
2O
3 after being regenerated several times reacts with H2S in low?calorie syngas with almost the same reactivity as that of fresh Fe
2O
3.
3) In the regeneration reaction, the intrapellet diffusion effect becomes increasingly significant as pellet size increases beyond 2 mm. The theoretical overall sulfurization rate showed fairly good coincidence with the measured rate when the intrapellet diffusivity of O
2 was assumed to be 2.25th-order with respect to the macro-porosity in the product layer.
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Susumu Yoshioka, Mizuho Hirato, Yoshihito Satomi, Hiromi Ozaki
1982 Volume 8 Issue 5 Pages
618-623
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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The relationship between the flowrate of solid particles issuing from a throat, which was installed at the lower end of standpipe, and the flowrate of a gas through an inlet located just above the throat has been studied experimentally, with the object of establishing a method of controlling the particle flowrate in a solid recirculation loop.
It was found that when the pressure drop across the throat was positive in the direction of solid flow, the flowrate of solid particles increased linearly with the flowrate of the added gas flowing through the throat. An experimental equation that correlates flowrate of solid particles with gas flowrate through the throat, throat diameter and the mean diameter and bulk density of the solid particles was obtained.
It was also found that the pressure drop across the throat was satisfactorily expressed by a theoretical equation derived from Ergun's equation.
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Chikao Kanaoka, Hitoshi Emi, Nobuaki Fujii, Munehide Yamaguchi
1982 Volume 8 Issue 5 Pages
624-628
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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It is known experimentally that much larger mist particles than the incoming ones are blown off from a fibrous filter as filtration of fine mists proceeds. However, the mechanism which causes this phenomenon is not yet elucidated.
In this work, the performance of the filter as a coagulator of fine mist particles was investigated by measuring the time dependencies of collection efficiency and pressure drop of the filter, and particle size distribution of mist from the filter.
Based on the experimental observations, a model which is capable of predicting the evolution of filter performance is also proposed.
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Takeshi Takahashi, Akira Kanagawa
1982 Volume 8 Issue 5 Pages
629-634
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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Collection efficiencies of aerosol particles by charged Nuclepore filters were studied theoretically and experimentally under conditions of the collection mechanisms of inertia, interception and electrostatic forces. The theoretical collection efficiency was determined numerically, using the capillary filter model given by Pich and a model of uniform charge distribution on the surface of a filter. The flow field through the filter was determined numerically by solving the Navier-Stokes equation.
The calculated results were compared with the experimental collection efficiencies of the Nuclepore filters measured with monodisperse polystyrene latex aerosols.
Collection efficiencies were significantly increased when the particle were charged. The increase of collection efficiency with increasing particle charges was explained in terms of the Coulomb force between charge on the particle and the filter surface.
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Itsuki Uehara, Eiichi Ishii, Hiroshi Ishikawa, Masanori Nakane
1982 Volume 8 Issue 5 Pages
635-642
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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A new hybrid water decomposition cycle consisting of the following four reactions is proposed.
4HBr → 2H
2 + 2Br
2 (electrolysis)
5/3As
2O
3 + 2Br
2 + 3H
2O → 2H
3AsO
4 + 4/3AsBr
3 (aqueous solution)
4/3AsBr
2 + 2H
2O → 2/3As
2O
3 + 4HBr (aqueous solution)
2H3AsO
4 → As
2O
3 + 3H
2O + O
2 (750°C)
Each constituent reaction was investigated thermodynamically and experimentally. It was proved that this cycle was advantageous in the source of thermal energy and the separation of products. The highest reaction temperature in the cycle was 750°C, which was required for the thermal decomposition of As
2O
5 to As
2O
3 and O
2. The products in each reaction could be obtained in two or three separate phases as a solid, a liquid, a gas and/or a concentrated aqueous solution.
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Toshiro Miyahara, Satoru Kaseno, Teruo Takahashi, Naohiro Shiragami, I ...
1982 Volume 8 Issue 5 Pages
643-653
Published: September 10, 1982
Released on J-STAGE: November 12, 2009
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1982 Volume 8 Issue 5 Pages
653a
Published: 1982
Released on J-STAGE: February 19, 2010
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1982 Volume 8 Issue 5 Pages
653b
Published: 1982
Released on J-STAGE: February 19, 2010
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1982 Volume 8 Issue 5 Pages
653c
Published: 1982
Released on J-STAGE: February 19, 2010
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1982 Volume 8 Issue 5 Pages
653d
Published: 1982
Released on J-STAGE: February 19, 2010
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1982 Volume 8 Issue 5 Pages
653e
Published: 1982
Released on J-STAGE: February 19, 2010
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1982 Volume 8 Issue 5 Pages
653f
Published: 1982
Released on J-STAGE: February 19, 2010
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1982 Volume 8 Issue 5 Pages
653g
Published: 1982
Released on J-STAGE: February 19, 2010
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1982 Volume 8 Issue 5 Pages
653h
Published: 1982
Released on J-STAGE: February 19, 2010
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