All issues
Predecessor
Volume 13, Issue 1
Displaying 1-22 of 22 articles from this issue
- |<
- <
- 1
- >
- >|
-
Yuji Kawai, Tadayuki Kikuma, Shigeru Matsumoto, Mutsumi Suzuki1987 Volume 13 Issue 1 Pages 1-5
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThe control of axial temperature distribution in a counter-current moving bed adsorber was carried out. Applications of modern multivariable control theory were studied through experimental work with air-glass beads and air-activated carbon systems. Satisfactory performance was achieved, though the control systems (the optimal multi-variable servo-control system and the decoupling controller) were designed on the basis of a simple phenomenological model.View full abstractDownload PDF (1043K) -
The effects of filling methods and hopper anglesRyuichi Moriyama, Genji Jimbo1987 Volume 13 Issue 1 Pages 6-12
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThere are reports that, for example, the wall pressure ratio in a bin cylinder after filling until discharge does not change, or that during discharge it increases due to the “switch” effect occurring in the bin. However, it is considered that the values differ according to experimental conditions.. Therefore, we carried out detailed investigations of the variation in wall pressure distributions with filling method and bin hopper angle using glass beads, rape-seed and sand respectively as bulk solids. It was found that the wall pressure after filling by central feeding is roughly twice that by peripheral feeding. On the other hand, that near the transition in a bin during discharge was influenced greatly by the hopper angles, so the wall pressure ratio after filling and during discharge varied 0.5 to 6 times at a certain place in the bin cylinder.View full abstractDownload PDF (3272K) -
Masaharu Yamada, Kohtaro Kuramitsu, Kazutaka Makino1987 Volume 13 Issue 1 Pages 13-19
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSWith the intention of establishing a new design method for bag filters, the mechanical strength of the dust layer collected on bag filter cloths is fundamentally studied on the assumption that the dust layer is consolidated as filtration proceeds. A new equation for the compression operating line for bag filters, which estimates the mechanical strength of the dust layer on the basis of both operating conditions of bag filters and mechanical properties of powders, is introduced. Its consistency is experimentally studied, using two kinds of fly ash (JIS No. 5, JIS No.10). The procedure for estimation of the mechanical strength is shown with an example.View full abstractDownload PDF (1139K) -
Hitoki Matsuda, Soo Kag Lee, Takashi Ishizu, Masanobu Hasatani1987 Volume 13 Issue 1 Pages 20-28
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSAs a step in the application of the Ca (OH) 2 /CaO thermochemical reaction cycle to chemical heat storage, the heat-release characteristics of a CaO packed bed accompanied by the exothermic hydration of CaO-H2O was studied both experimentally and theoretically.
It was found that after water vapor had been introduced into the CaO packed bed, the bed temperature immediately rose to the reaction equilibrium temperature, which is determined by the partial pressure of the water vapor, and remained almost constant at this temperature during the course of the reaction. The duration of the heat-release period was found to be approximately proportional to the inlet gas temperature and inversely proportional to the gas flow rate. The theoretical results obtained by solving fundamental differential equations derived with a few assumptions agreed fairly well with the experimental data, and the fundamental heat-release characteristics of the CaO packed bed were considered to be well explained by this theoretical modeling. It was also observed that the heat-release characteristics undergo no negative change with repetition of the heat-storage/heat-release cycles.View full abstractDownload PDF (1658K) -
Hirotoshi Tanaka, Makoto Akiyoshi, Noriaki Kaneki, Hiroshi Hara1987 Volume 13 Issue 1 Pages 29-33
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSOvervoltage and current curves of an alkaline fuel cell with a fluidized-bed oxygen electrode were analyzed by use of a two-phase model. A specific resistivity, a specific surface area of catalyst and an effective length of charge transfer presenting characteristic values of the oxygen electrode were estimated for an exchange current density.View full abstractDownload PDF (979K) -
Sturtevant- and Gayco-type model air classifiersMasao Yamazaki, Genji Jimbo, Tadashi Koike1987 Volume 13 Issue 1 Pages 34-42
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSAir classifiers have been used widely in closed-circuit grinding by many industries. The cut size of the classifier is estimated when the velocity distribution of air flow and the particle ejection velocity at the distributor are known. So the three-dimensional air velocity distribution in a classifier is the basis of an analysis of classification.
The complicated air flow in a classifier can be measured exactly by a spherical five-hole Pitot tube, and a formula for the laminar incompressible steady flow for a cylindrical annulus is found to be applicable to the axial component of air velocity there as a rough approximation.
The volumetric air flow in the classifier is well represented by Nakajima' s equation for a standard flat turbine blade or Tanaka' s extension of that equation to the main blade of a classifier.
A model Sturtevant-type air classifier with two-motor drive has made clear the function of two-blade systems; i.e., the main and auxiliary blades are related to the axial and tangential velocity components, respectively.
The degree of control valve opening is also related to the air velocity distribution within the inside drum of the classifier, but the volumetric air flow rate is not so much affected by the action of the control valve.View full abstractDownload PDF (1310K) -
Hideki Murakami, Tatsuji Okada, Tomoshige Nitta, Takashi Katayama1987 Volume 13 Issue 1 Pages 43-50
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSSolubility data for six rancid substances-trimethylamine, methyl mercaptan, methyl sulfide, dimethyl disulfide, acetaldehyde and styrene-in water were determined at 0, 25, and 50°C by means of a gas stripping method. The accuracy of experimental Henry's constants is estimated to be ± 3%. For trimethylamine and methyl mercaptan, which are weak electrolytes in water, solubilities in aqueous buffer solutions differing in pH were determined by measuring vapor-phase concentrations; they are well correlated by a dissociation model. However, there are small but appreciable differences between the mixed dissociation constants determined in the present work and those estimated from the thermodynamic dissociation constants reported in the literature. Empirical expressions for Henry's constants and ionic dissociation constants are presented for eight rancid substances in water by adding literature data for ammonia and hydrogen sulfide; the expressions are applicable at temperatures ranging from 0 to 50°C.View full abstractDownload PDF (1154K) -
Hiroshi Taoda, Kiyoshi Hayakawa1987 Volume 13 Issue 1 Pages 51-57
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSTo estimate the extent of thermal oxidative aging of pentaerythritol used as a latent-heat-type thermal storage material, the deterioration of pentaerythritol was investigated by applying over two months the following heating-cooling cycle, which simulated the daily insolation : that is, 8-hour holding at 200°C as the highest temperature in a day followed by 5-hour holding at 30°C as the lowest. Several changes in pentaerythritol by the heating-cooling cycles, e.g., weight decrease, decrease in oxygen content, production of carbonyl compound, and lowering of the heat of transition and of the transition temperature, are thought to be caused by sublimation, thermal oxidative decomposition and crosslinking between radicals produced. Radical scavengers effectively suppressed the thermal degradation of pentaerythritol. To use pentaerythritol as thermal storage material, the suppression of sublimation, of oxidation and of radical production are required.View full abstractDownload PDF (1225K) -
Yukio Nakanishi, Masao Kobari, Yukio Shimizu1987 Volume 13 Issue 1 Pages 58-62
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThe characteristics of holdup and mixing in a continuous mixer consisting of a series of equal-size twin-shell mixer units were studied.
The equation showing the holdup of solid materials in the mixer was derived by material balance. Experiments were carried out on a glass particles system and the results agreed well with predicted values.
The characteristic of the mixing of glass particles in the mixer was determined by measuring the response at the outlet to a step input of a tracer. A flow model for the mixer of M twin-shell mixer units was developed by 2M perfect mixing tanks in series with the volume of half the holdup of the corresponding mixer unit.
The response curve derived from the flow model agreed well with experimental data.View full abstractDownload PDF (1026K) -
Hua Liang, Tatsuo Tanaka1987 Volume 13 Issue 1 Pages 63-70
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThe heat balance in a cylindrical deposit of combustible dust placed in hot environments may be described by a differential equation, according to the thermal theory. First, the equation was solved numerically by using the finite element method for the dust, whose physical and chemical properties were available, to confirm whether the resulting ignition temperature and induction time to ignition show good agreement with the experimental data currently reported by Leuschke. Secondly, all variables involved in the differential equation were reduced to dimensionless groups, so that the relationship between the dimensionless groups can be simulated. Empirical correlation was attempted for calculating the ignition temperature and the induction time from the physical properties of given dust and operational variables. A nomogram was proposed to readily determine the ignition temperature. It may be concluded that if the relevant properties are available, self-ignition behavior can be well predicted in the storage and handling of cylindrical dust deposits.View full abstractDownload PDF (1509K) -
Takeichiro Takamatsu, Tori Hashimoto, Masahiro Ohshima, Hiromu Ohno1987 Volume 13 Issue 1 Pages 71-77
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSModel Predictive Control (MPC) is studied in terms of structure and degree of freedom. It is made clear that the control structure of MPC has feed-forward and feedback elements with an integral action. Furthermore, MPC is extended to a control system with two degrees of freedom by introducing two independent tuning parameters. The usefulness of the extended system is confirmed through simulations and experiments.View full abstractDownload PDF (1272K) -
Ikuro Shishido, Toshiro Maruyame, Minoru Funaki, Shigemori Ohtani1987 Volume 13 Issue 1 Pages 78-85
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSEffects of moisture content on mechanical properties (Young's modulus, yield stress, tensile strength), and transport properties (permeability, osmotic suction pressure) of clay were studied experimentally.
According to the consolidation theory in soil science, stress and osmotic suction pressure gradients are considered to be the effective driving force of liquid transfer in the clay.
Predicted local moisture content coincide well with experimental value. Further, calculated stress distribution indicates that rapid drying rate causes internal tensile stress in material extensively.View full abstractDownload PDF (1337K) -
Naohiro Shiragami, Toshio Kajiuchi, Minoru Hatayama1987 Volume 13 Issue 1 Pages 86-92
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSSettling enhancement effect in a settling tank with inclined plates was studied experimentally. A new model for settling rate was proposed by taking notice of clear liquid flow and sludge flow along the inclined plate. The relationship between height of settling interface and settling time was obtained. Maximum settling enhancement was achieved at the upper edge of inclined plate. Dependence of the geometrical factor of the inclined plate on the maximum settling rate was appraised by the term Lsin θ/H, which is the ratio of projected area of the inclined plate to cross-sectional area of the settling tank. The relationship between height of settling interface and settling time calculated from the proposed equation was in good agreement with experimental results.View full abstractDownload PDF (1394K) -
Satoru Kato, Junjiro Kawasaki1987 Volume 13 Issue 1 Pages 93-99
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSSeparation of aromatic hydrocarbons from naphtha by liquid membrane permeation was conducted in a stirring vessel by use of isooctane as a solvent and saponin as the emulsifying agent.
Although membrane breakup was negligible, mechanical entrainment of the solvent was remarkable when the amount of membrane solution in O/W emulsion was large. Use of liquid membranes prepared in the stirring vessel allowed severe mechanical entrainment which often caused phase inversion from O/W/O type to O/W type emulsion, while liquid membranes prepared in a high-speed homogenizer did not. Stable contact operations were observed in the latter case even when the amount of membrane phase was relatively large.
Permeation rates of aromatics through the liquid membranes were far higher than those of saturated hydrocarbons. Permeation of hydrocarbons increased with decreasing concentration of glycerin used as a membrane strengthening agent and with increasing amount of solvent.View full abstractDownload PDF (1223K) -
Yutaka Matsumoto, Shin-ichi Nakao, Shoji Kimura1987 Volume 13 Issue 1 Pages 100-106
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSCross-flow filtrations of ovalbumin and dextran solutions were carried out with four ceramic microfiltration membranes having respective pore diameters of 0.2, 0.8, 1.5 and 3.0μm. The effects of applied pressure. feed flow velocity, feed concentration and pore diameter on permeate flux and solute rejection were studied.
Although the pore diameter was much larger than the diameter of an ovalbumin molecule, rejection was more than 90% in all experiments. The limiting fluxes were obtained, and lower feed velocity and higher feed concentration resulted in a lower limiting flux.
The fluxes obtained in filtration of the ovalbumin solution were much lower than the pure water flux. Permeate resistance of the gel layer and that of plugging could well explain the cause of these low fluxes. Since the degree of plugging depended on membrane pore diameter, an optimum pore diameter for obtaining high flux existed.
Dextrane was hardly rejected with the ceramic membranes used. The flux gradually decreased with time because of plugging of the pores.View full abstractDownload PDF (1077K) -
Ikuho Yamada, Setsuro Hiraoka, Tsutomu Aragaki, Takumi Okamura1987 Volume 13 Issue 1 Pages 107-109
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSUnsteady thermal conduction problems in the form of ∂φ/∂θ=α∇2φ were numerically solved under the Dirichlet condition, by using the explicit finite difference method, and the effect of initial boundary value on the predicted results was studied.
1-dimensional problem was solved by using the scheme;
φp, r+1=1/6 [(+1)-(+4)-(+1)] φp, r
where subscript “p” denotes the spatial point and “r” the time step. For 2-dimensional problem, the analysis was based on a new scheme :
φp, q, r+1=1/36 [(+1)-(+4)-(+1)-(+4)-(+16)-(+4)-(+1)-(+4)-(+1)] φp, q, r
The choice of initial boundary values, φ0, 0 (=φN, 0) for 1-dimensional andφ0, q, 0 (φp, 0, 0=φN, q, 0=φp, N, 0) for 2-dimensional, was of importance, especially for the initial stage, in view of the accuracy of the results.By taking this into account, the same optimal value of 0.5 was found for both 1-dimensional and 2-dimensional problems.View full abstractDownload PDF (351K) -
Katsumi Tsuboi, Shigendo Akita, Katsuroku Takahashi, Hiroshi Takeuchi1987 Volume 13 Issue 1 Pages 110-113
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSWater permeation through oil layers of kerosene containing Span 80 was studied in water-in- oil- in water ((W/O) /W) emulsions under suppression of entrainment due to emulsification of the outer aqueous phase and of mechanical breakdown of (W/O) droplets. Water permeabilities Po were determined from the time-dependent change of water content the value of Po for permeation from the inner to the outer aqueous phase was found to be 0.7 × 10-5cm/s for NaCl solution system at a Span 80 content of 3 wt%. For the H2SO4 solution system, however, Po was affected by the concentration difference. On the other hand, the presence of NaCl or H2SO4 in the aqueous phase has little effect on the solubility of water in Span 80-kerosene solution. This suggests that it is not valid to interpret water permeation through the thin oil layer in terms of solubilization.View full abstractDownload PDF (596K) -
Mitsuaki Hirota, Yoshio Shimizu, Toshio Oshima1987 Volume 13 Issue 1 Pages 113-116
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThe effect of the flowability of dust on the collection performance of filter cloth was studied by using three kinds of dusts of different flowabilities. In the case of dislodging the filter cloth, the amount of dust remaining on the dislodged filter cloth was considerably affected by the flowability of the dust. For dust of low flowability, pressure drop across the filter cloth and collection efficiency were higher than for dust of high flowability when the same amount of dust remained on the filter cloth.View full abstractDownload PDF (2256K) -
Tamotsu Hanzawa, Hideki Ishihara, Kuniaki Sekiguchi, Takahiko Fujii, Y ...1987 Volume 13 Issue 1 Pages 116-121
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSTo analyze the heat transfer phenomenon in electronic circuit plates, natural convective heat transfer between two vertical parallel plates, with symmetric or asymmetric uniformly heated wall, was investigated experimentally in the range of high Grashof number (Gr=103-107).
The local heat transfer coefficient was strongly affected by the axial distance of the plate in the case where distance and temperature difference between plates were small. Average Nusselt number was affected by Grashof number, distance and temperature difference between the plates. An empirical equation for average Nusselt number in the two vertical parallel plates was obtained.View full abstractDownload PDF (959K) -
Shintaro Furusaki, Tetsuya Suzuta1987 Volume 13 Issue 1 Pages 121-124
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSRate of adhesion/detachment of bovine T-cells to or from polyethylene-based materials was studied according to a mechanism consisting of consecutive reversible and irreversible adhesion. Polyethylene and a graft copolymer of polyethylene and poly-2-hydroxyethylmethacrylate were used. Time dependence of concentration of free and adhered T-cells can be expressed by the mechanism. The detachment rate hardly changed with temperature, but the rate of adhesion increased with increasing temperature. The activation energy of the latter was 20-40kJ/mol.View full abstractDownload PDF (622K) -
Tsutomu Hirose1987 Volume 13 Issue 1 Pages 124-127
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSDifferential heat balance equations for the regenerative heat exchanger are expanded into a power series of small value of cycle time to obtain a perturbation solution. Its thermal effectiveness is given by the same performance equation as that for countercurrent continuous heat exchanger when an additional resistance to heat transfer brought about by periodic regeneration is added to overall heat transfer resistances in process and regeneration cycles. The new resistance is a simple function that increases with the square of the ratio of heat capacity of fluid entering during one cycle time to that of heat storage medium. The proposed expression successfully correlates representative results of available numerical analyses.View full abstractDownload PDF (626K) -
Masahiro Takahashi, Akinobu Uemura, Kazuhiro Higashi, Hiroshi Takeuchi1987 Volume 13 Issue 1 Pages 127-130
Published: January 10, 1987
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThe stripping rates of cadmium from n-heptane solution containing Cd-D2EHPA complex by hydrochloric acid were measured with a stirred transfer cell, and the rate data were correlated as a function of the concentrations of hydrochloric acid, Cd-D2EHPA complex and uncomplexed D2EHPA.
The expression for this stripping was coupled with an equation for the extraction and the extraction equilibrium formulation published previously, and the mass-action constant as the ratio of the two rate constants was found to give the extraction equilibrium constant.View full abstractDownload PDF (535K)
- |<
- <
- 1
- >
- >|