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Shigeru Hagimori, Tsunenobu Fukuda, Chiaki Kuroda, Masaru Ishida
1993 Volume 19 Issue 3 Pages
353-359
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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In a fed-batch process of yeast fermentation with non-linear complicated biological reaction, we applied a neural network to determine the starting time of operation for by-production. Determination of that time has been made by an operator's intuition and experince, because the process is complicated and has a radical change of state.
We proposed two types of network. One suggests the starting time of operation for by-production and the other indicates the degree of by-production. The former can be applied to automation of operation for by-production and the latter to support for operators. The methods to estimate the generalization power of networks were discussed and the best networks of both types were obtained, showing their potential applicability to automatic operation for by-production or to support for operators by warning them of the start of by-production.
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Yoshiaki Sawada, Yoshiteru Kageyama, Masashi Iwata
1993 Volume 19 Issue 3 Pages
360-366
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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The mechanism of particle formation by pyrolysis of Fe (CO)
5 and a technique for changing primary particle diameter were studied.
The size distributions of the primary particles are almost log-normal and their geometric standard deviations are 1.21.4. The Mechanism of particle growth by this method consists of two steps : the first is nucleation and condensation in the inlet part of the reactor, and the second is coagulation and coalesence in the following part of the reactor. The primary particle diameter is affected by feed concentration, residence time, pre-decomposition ratio of Fe (CO)
5 and temperature of hot diluent nitrogen and reactor wall, in which the first, second and third factors are the most effective in controlling the diameter. The magnetic flux in the axial direction of the reactor does not affect the size of the primary particle, although it results in a necklacelike chain of the particles.
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Tomohide Watanabe, Hitoki Matsuda, Masanobu Hasatani
1993 Volume 19 Issue 3 Pages
367-373
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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As a step toward a new high-temperature dry desulfurization system with magnesite particles, the reactivity of MgO particles calcined at various temperatures for sulfurization was studied with thermogravimetric analysis (TGA) at various reaction temperatures. The effect of water vapor, which coexisted in flue gases, on calcination and sulfurization was also studied.
The reactivity of calcined magnesite for sulfurization was found to have the maximum for calcination temperatures though the specific surface area and pore volume of calcined magnesite decreased with increase in calcination temperatures. The activation energy for sulfurization of magnesite calcined at 1273K was about 47.29 kJ/mol. It was observed that magnesium oxide produced from the calcination of magnesite in the coexistence of water vapor has lager pore volume and pore diameter than in N
2 atmosphere. However, its reactivity for sulfurization was lower than that produced under the atmosphere free from water vapor. Moreover, in the case of the coexistence of water vapor during both calcination of magnesite and sulfurization of calcined magnesite, the sulfurization reactivity was also lower than that under the water-vapor free atmosphere.
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Mikio Kumita, Fujio Watanabe, Masanobu Hasatani
1993 Volume 19 Issue 3 Pages
374-380
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Using granular molecular sieving carbon (MSC) produced from polyvinyl alcohol (PVA) /phenolic resin, measurements of adsorption equilibria and adsorption rates of single-component systems of N
2 and CO
2 were carried out. The amount of CO
2 adsorbed on the MSC was larger than that of N
2 at equilibrium, and the MSC had a higher diffusivity ratio of CO
2 to N
2 than did the active carbon.
In addition, an experiment on CO
2 separation from a mixed gas of N
2/CO
2/H
2O by the pressure swing adsorption (PSA) method using the MSC was carried out. The following results were obtained. 1) CO
2, of which the concentration was 15 vol. %, was concentrated to a maximum value of 68 vol.% under a CO
2 yield of more than 0.96. There was no significant effect of water vapor content in the feed gas on the CO
2 separation capabilities. 2) The adsorption cycle time and the waste gas flow rate significantly affected CO
2 separation by the PSA method. The temperature changes in an adsorption column supported this conclusion.
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Yoshitake Suzuki, Atsushi Koizumi, Yasushi Takeuchi
1993 Volume 19 Issue 3 Pages
381-388
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Adsorption of trihalomethane from aqueous solution on activated carbon fiber and granular activated carbon was examined in this study. As a result, adsorption isotherms for trihalomethane-activated carbon fiber and granular activated carbon system were fitted to the Freundlich equation and could be also approximated to the Henry equation because the slope of those fitting lines was nealy unity. Breakthrough curves for chloroform could be analyzed as a linear equilibrium. system by using Babcock's method in the case of activated carbon fiber and Rosen's analytical solution in the case of granular activated carbon. In the latter case, those surface diffusivities were 2.16.6 × 10
-12m
2·s
-1, and in the former case the Peclet number
Pe was about 4.8×10
-3.
The product (
k·n) of two equilibrium parameters for the Freundlich equation and a factor (β) for the Henry equation related to boiling point
Ts of trihalomethane and the slope of lines related were similar, regardless of kinds of activated carbon used. However, the intercept was different from the value for the other activated carbon because of interaction between trihalomethanes and surfaces of the activated carbon.
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Mamoru Tomita, Masaru Ishida
1993 Volume 19 Issue 3 Pages
389-397
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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The whole structure of a recipe - driven autonomous distributed operation and management system for pipeless chemical batch plants was proposed.
The process sequence of a product is written in a form of the recipe that has a hierarchical structure consisting of several sub-recipes describing individual unit processes. Each sub-recipe is to be distributed to a contracted hardware.
For efficient operation and management by autonomous units, it was found that a common expression for handling time is required, and a concept of time with uncertainty for the estimated time required was proposed. Also, messages as a communication mechanism among units were introduced. As examples, the request for use of pathway to a traffic manager and the report of the process history and results experienced, which are inserted into the instance recipe to save the production history, were illustrated. The above mechanism made it possible for both material and information to be combined and integrated.
Moreover, autonomous optimization for efficient operation by each reactor was discussed with the aim of keeping the time limit for delivery and to improve the rate of operation of units.
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Satoshi Syoya, Keisuke Fukui
1993 Volume 19 Issue 3 Pages
398-403
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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In the turbulent boundary layer flow developed between parallel flat plates, density-stratified flow is generated by a heating wall. In such a mixed density-stratified turbulent flow, velocity and temperature were measured simultaneously. The flow structure and turbulent transport mechanism were investigated. The difference of developing processes in the stable and unstable regions resulted in the unsymmetrical profiles of velocity, temperature and turbulent quantities. From measurements of coupling probability density distribution, it was coinfirined that the thermal plume generated intermittently in the unstable region affected the turbulent structure in the stable region. The phenomenon of counter-gradient turbulent diffusion of heat was observed at the interface.
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Naoki Iwata, Satoru Kato, Hidetaka Noritomi, Kunio Nagahama, Yoshihiro ...
1993 Volume 19 Issue 3 Pages
404-410
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Experimental data of the pervaporation of aqueous ethanol solutions through aromatic polyimide hollow fiber were obtained. The effects of temperature, pressure and the composition of aqueous ethanol solution on permeability and selectivity were experimentally examined. The values of the separation factor of water were between 16-55. It was found that the overall permeation coefficient defined with fugacity difference across a membrane was the most rational for the simple evaluation of permeation fluxes in polymide, because the values of the permeation coefficient defined with the fugacity difference were kepe constant for the data over wide ranges of feed compositions and temperatures. The permeation coefficient for water was three tunes that in vapor permeation at higher temperature, and that for ethanol was twenty times higher.
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Yoshiyuki Endo, Yasuo Kousaka, Yasunobu Nishie
1993 Volume 19 Issue 3 Pages
411-417
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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The physical meaning of equilibrium moisture contents in powdery materials at a certain humidity (30v 90 %) is discussed and the capability of moisture control in powder is examined.
Wet powdery materials just before entering drying processes after some wet processes usually contain much or less soluble impurities (mostly salts). Such impurities will be concentrated in drying processes, and they cover particle surfaces or are contained in liquid bridges formed between particles. Our former analysis and experimental results for liquid bridges formed between two spherical particles, in which the liquid bridges contain a certain amount of soluble impurities, have been applied to evaluate the moisture contents in powdery materials. It was found from the analysis that the moisture contents in powder could be predicted from the amount of soluble impurities contained in the powder and the surrounding humidities. This suggests that the moisture contents in the powder which is equilibrated by surrounding air in high humidity can be controlled by the soluble impurity concentration in wet powder being fed to drying processes.
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Hiroshi Takahashi, Kouji Miwa, Ken-ichi Kikuchi
1993 Volume 19 Issue 3 Pages
418-423
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Praseodymium-neodymium mixture solution containing a complexing agent, EDTA or DTPA, was electrically dialyzed. The metals were effectively separated with the help of the complexing agent, while no separation was observed in its absence. The separation factors defined as a flux ratio of praseodymium to nedymium attained 1.7 for EDTA and 2.1 for DTPA. The separation characteristics were affected by the pH of solution and the concentration of complexing agents. All the experimental results were well explained by a model, based on the Nernst - Planck equation, where the selectivities of complexing agents and membranes and the migration in membrane were considered. The model analysis revealed that the separation characteristics for the two metals were estimated from the difference between the concentrations of the free (uncomplexed) metal - ions caused by the difference between the stability constants of the metal complexes.
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Muneharu Goto, Masahiro Goto, Fumiyuki Nakashio
1993 Volume 19 Issue 3 Pages
424-430
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Several surfactant-coated enzymes were prepared by coating various origin of lipase with nonionic surfactant dioleylglutamic acid ester ribtol (2C
18Δ9GE) whose structure is similar to that of lipid. Selective hydrolysis reaction of triglycerides was investigated with the surfactant-coated lipase in organic media under water content-limited conditions. In this reaction system, the most suitable solvent is iso octane and the surfactant-coated lipase prepared by
Candida cylindracea gives the highest hydrolysis yield of triolein. Selective hydrolysis of triolein can be performed by adjusting water content in iso octane. Assuming the Michaelis-Menten mechanism, apparent reaction rate constants were obtained by the analysis of initial reaction rate. The rate constant of surfactant-coated lipase was tens times that of powder lipase.
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Hidetoshi Mori, Masafumi Taguchi, Masaaki Nakamura, Shigeki Toyama
1993 Volume 19 Issue 3 Pages
431-439
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Saturated permeability of mesh-type wicks was measured to verify the conventional geometric model, in which the shape of the woven structure of the screen wick was represented by piecewise arcs and clearance between layers. ' The result permitted a correlation of the saturated permeability from the hydraulic diameter of the wick and the product of the friction factor by the Reynolds number.
The relationship between capillary pressure and saturation was also measured and it was found that the Leverett function was applicable to correlating the reduced saturation of the plain-woven mesh. The unsaturated permeability was predicted by presuming the wick to be an assemblage of capillary tubes of various radii determined from the capillary potential curve. The saturation profiles in wicks at constant infiltration rates and steady draining were studied in connection with those predicted by water movement theory in unsaturated porous media at steady state.
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Katsuroku Takahashi, Hajime Nakashima, Susumu Nii, Hiroshi Takeuchi
1993 Volume 19 Issue 3 Pages
440-445
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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A multistage mixer-settler extraction column, which achieved larger throughput at higher agitation rate, was developed. Each stage consisted of an upper settler chamber and a lower mixer chamber with a lifter-turbine impeller. The continuous phase was led through a downspout from the settler to the mixer of lower stage, and the dispersed phase through a riser from the settler to the mixer of upper stage. The large throughput is produced by the suction pressure with the lifter-turbine impeller, which was ascertained by the measurements of pressure in the column. The operation was stabilzed by installing a drop coalescer between the settler and the mixer, and a lattice of mesh sheet coated with PTFE gave superior performance as the coalescer.
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Ryoichi Kuboi, Koji Yano, Hisakazu Tanaka, Isao Komasawa
1993 Volume 19 Issue 3 Pages
446-454
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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A systematic investigation of surface hydrophobicity of proteins was carried out by examining the partition behaiviors of various proteins with differing properties in three aqueous two-phase systems such as PEG/dextran, PEG/dextran spiked with a non-ionic surfactant, Triton, and Triton/salt systems. The proteins examined were three lipases from different origins, origomeric β-galactosidase, and cytochrome c in native, acid-induced molten-globule, and denatured states. Although each protein has its own characteristic hydrophobic nature, the hydrophobicity can be classified at least into two groups. One is surface net hydrophobicity, which can be quantified by the first method. The other is the local hydrophobicity originating from the hydrophobic binding site on the surface evaluated by the latter two methods. These two hydrophobicities showed different tendencies, especially for the cytochrome c in acid-induced molten-globule and denatured states. Conventional methods such as hydrophobic chromatography can be applied only for the measurement of local hydrophobicity. These hydrophobicity differences can be exploited for effective separation of proteins.
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Toshihiko Shakouchi, Itsuki Kajino
1993 Volume 19 Issue 3 Pages
455-461
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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The flow and heat transfer over a step (forward or backward facing) result in complicated characteristics such as flow separation and the generation of vorticies, and present interesting information for improving the heat transfer on the surface.
This study presents investigations on the flow and forced convection heat transfer over forward facing sets of double steps. Measurements of velocity and turbulence intensity, flow visualization, and heat transfer over the forward facing double steps with various step ratios,
L/α (
L : step length, α : step height), were carried out. From these results, the relations between the flow and heat transfer characteristics and the step ratio were made clear, and a considerable heat transfer enhancement of the double steps compared with the single step or flat plate was confirmed. The following relations between the mean Nusselt,
Nu, and Reynolds numbers,
Re.
Nu=0.0036
Re (for
L/α =2, 4),
Nu= 0.00263
Re+7 (for
L/α= 0)
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Yushi Hirata, Hiroshi Adachi, Kunihiro Katsurada, Akiko Hiramatsu, Ryu ...
1993 Volume 19 Issue 3 Pages
462-469
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Hydrogen bubbles were generated continuously from an electrode wire strained along the pipe diameter in order to investigate the turbulent deformation process of a fluid material interface in a turbulent pipe flow. The hydrogen bubbles behaved like a curtain hung on the electrode wire and can be regarded as tracers marking an interface of two fluids divided by the diameter electrode. Influences of wall turbulence on the behavior of the hydrogen bubble curtain are described using the light-and-shade patterns on its side-view images. The end-view images were processed on a personal computer to quantitatively determine the turbulent displacement and elongation process of a material interface in terms of the intensity, integral scale, eddy diffusivity and elongation rate of the fluctuating hydrogen bubble curtain.
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Eiji Suzuki, Kentaro Oguchi, Shui-liang Yao, Hajime Nishimura
1993 Volume 19 Issue 3 Pages
470-475
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Cellulose dipped in 10% H
2SO
4 and then incubated for severai hours at 60°C could eliminate NO
2 from room air at room temperature and atmospheric pressure. The elimination reaction was studied using a continuous-flow tubular reactor packed with cellulose treated with sulfuric acid. The relative decrease of NO
2 was 90% at the beginning and was maintained at over 50% for running time of over 600 hours with 1.3 kg.min/m
3 of
W/F, where W is the mass of the treated cellulose in the reactor and
F is the flow rate of the air containing NOx to the reactor. About 30 to 70% (90% at the beginning) of the eliminated NO
2 was reduced to NO. The rate of NO
2 elimination was a function of the first order of the NO
2 concentration. The rate of reaction reducing NO
2 to NO seemed to be a higher-order function of the NO
2 concentration.
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Hideto Yoshida, Tatsuya Saeki, Toshiyuki Fujioka, Tetsuya Ueda, Tadash ...
1993 Volume 19 Issue 3 Pages
476-482
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Experimental and theoretical studies were conducted on the separation of submicron powder by use of a revised type of cyclone. The cyclone has a movable inlet guide plate at the inlet section, and 50% cut size is controlled from 0.45 to 0.75 gm by changing the inlet clearance of the guide plate. But the 50 % cut size increases again under the condition of very narrow inlet clearance of the guide plate, because the radial velocity of particles decreases and fluid turbulence increases in the case of very narrow inlet clearance.
The 50% cut size decreases to about 0.4 μm by use of both the inlet guide plate and the blowdown method. The partial separation efficiency with a spiral-inlet cyclone is higher than a cyclone with tangential inlet, and the 50 % cut size decreases with a highly polished inside wall surface.
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Hideharu Yagi, Shigeri Ueyama, Shinji Inoue, Satoshi Okumura
1993 Volume 19 Issue 3 Pages
483-488
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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The separation of inhibitory products from the reaction system is effective in the enzymatic hydrolysis of cellulose. Partitioning of cellulase, cellobiose and glucose between coacervate and equilibrium phases was studied with the object of applying the gelatin-Na
2SO
4-water simple coacervation system to an extractive reaction. Cellulase was concentrated into the coacervate phase, but cellobiose and glucose were evenly partitioned. Seinibatch hydrolysis of cellulose in the coacervation system was carried out in a stirred vessel. Intermittent removing of products in the equilibrium phase made it possible to achieve high conversion. The simulation of seinibatch reaction based on the kinetic constants obtained from the time course of batch reaction and the partition coefficients obtained from the partitioning experiments showed that the loss of enzyme was sparse. The coacervation system is better than the PEG-Dextran system with respects to the price of phase-forming materials, the tune to separate two phases and the temperature suitable for both phase formation and reaction.
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Yoshiyuki Bando, Makoto Nishimura, Yoshinori Watanabe, Atsushi Sato, M ...
1993 Volume 19 Issue 3 Pages
489-495
Published: May 10, 1993
Released on J-STAGE: February 19, 2010
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To improve bubble column performance, a bubble column with packed perforated draft tube was proposed. Net rings having relatively small flow resistance were used as packings and the dimensions of the perforated draft tube and the net ring were varied. The flow pattern was observed, and the gas holdup, gas-liquid interfacial area and liquid mixing time were measured.
By packing the net rings in the perforated draft tube, “bubble subdivision by pack-ings” occurred in addition to “bubble subdivision by perforated wall”. The draft tube diameter, pore diameter, fractional free area and opening of net ring had the optimum values for the gas holdup and gas-liquid interfacial area. When the optimum draft tube diameter was used, the gas holdup and gas-liquid interfacial area were almost equal to those of the packed bubble column. The liquid mixing time was much shorter than those of standard and packed bubble columns. The COD removal was almost equal to that of the packed bubble column, and the present column was expected to be applied to a waste water treatment.
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Shinji Kambare, Takayuki Takarada, Nobuyoshi Nakagawa, Kunio Kato
1993 Volume 19 Issue 3 Pages
496-504
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Eighteen coals covering wide ranks from semianthracite through subbituminous coal were burned in a turbulent-flow furnace under two-stage combustion to investigate the influence of coal composition on nitric oxide formation. These experimental results showed that the conventional model could not reflect the influence of coal properties on NO formation during the initial stage.
Fuel nitrogen mainly decomposed into gas phase as HCN, NH
3 and N
2. Both the behavior of devolatilization and yields of volatile nitrogen species differed among coal ranks. It seemed that these species affected NO formation during the initial stage, because they differ from one another in rate of NO formation and destruction. On the basis of the data of both the pyrolysis and the laminar flow combustion, devolatilization rates of HCN, NH
3 and N
2 were determined.
A model combined with the devolatilization paths of volatile nitrogen species was proposed to explain the influence of coal composition on NO
x formation during the initial stage of combustion. One-dimensional analysis based on the proposed model was performed by using the overall reaction rates. Calculation results were compared with experimental data from the turbulent flow furnace. The proposed model gave a better fit of the data than did the conventional model.
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Takayuki Takarada, Hidenori Sakamoto, Keiji Maehara, Makoto Ito, Tomok ...
1993 Volume 19 Issue 3 Pages
505-510
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Reduction of iron oxide fine particles which were generated at a converter was carried out by using a new type of fluidized bed, a powder-particle luidized bed. Effects of operational conditions of the fluidized bed, i. e., temperature, bed height, gas velocity and hydrogen concentration of inlet gas on the conversion of reduction were examined. 98% of the maximum conversion was obtained in a laboratory-scale fluidized bed. Since oxidization activity of the reduced fine particles was very high, high temperature treatment of the reduced particles or preoxidation of the particles with low concentration of oxygen were needed to prevent the reduced fine particles from re-oxidation.
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Fumihiro Koizumi, Hirokazu Nishitani, Shigeharu Toyoda, Eiichi Kunugit ...
1993 Volume 19 Issue 3 Pages
511-518
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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A new method was developed to identify every particle from the closed contour line of the overlapped particle image separated from the background. The largest inscribed circle is obtained for each arc on the contour line by a simple algorithm. In this method all particles can be recognized correctly when each particle has a spherical shape. This method was applied successfully to the actual overlapped particle image.
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Osamu Miyatake, Katsuhiro Kodama, Takayuki Hashimoto, Yoshimasa Ando
1993 Volume 19 Issue 3 Pages
519-525
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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As an attempt to develop an efficient steam accumulator, an experimental investigation has been made of the effect of injection of bubble nuclei generated by electrolysis on the flash evaporation of warm water exposed to a sudden pressure drop in a container.
From the results, it is realized that artificial nucleation enhances the flash evaporation of the pool water, thereby increasing the flash evaporation efficiency in the late evaporation period, especially for the cases of lower liquid temperature, higher liquid level and smaller superheat. Semi-empirical equations are deduced for predicating the practical evaporation efficiency when the mass velocity of vapor declined to any given values, from the dimensionless depth of the superheated zone and the mass velocity of electrolytic gases.
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Fang-Zhi Liu, Ikuho Yamada, Hideki Mori, Chizu Nakao
1993 Volume 19 Issue 3 Pages
526-529
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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A numcrical method is proposed for solving ternary nonisothermal multistage extraction problems by the relaxation method. The algorithm was developed by adding a temperature correction loop to the method previously proposed by Liu et al. for isothermal cases. The enthalpy balance for the temperature correction includes heat flows to/from the surroundings and heat of mixing. Although empirical equations are employed for predicting ternary liquid - liquid equilibria, the method can be extended to multicomponent systems by applying other thermodynamic methods. The stability of the proposed method is illustrated by sample calculations.
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Toshiro Miyahara, Nobuhiro Tatsumi
1993 Volume 19 Issue 3 Pages
529-532
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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The experiments were carried out at relatively low superficial gas velocity (0.12-0.918cm/s) using three types of solid particles and four kinds of draught tubes to investigate the volumetric mass transfer coefficient,
kLa, of a solid-suspended bubble column with a draught tube containing low-density particles similar to biocatalysts used in biochemical processes. The presence of suspended solid particles in the column reduces the value of
kLa, and the reduction increases with increasing solids holdup and with decreasing draught tube diameter. An empirical equation for
kLa is proposed for a homogeneous dispersion of particles. It is a modified form of the correlation obtained by Muroyama
et al., who used a relatively large superficial gas velocity (1.5-20 cm/s).
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Chiaki Hatanaka, Toshihide Haraguchi, Shunsuke Ide, Chisato Kajiyama
1993 Volume 19 Issue 3 Pages
533-536
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Lipase was immobilized in highly crosslinked polyacrylamide gel by plasmainitiated polymerization of acrylamide and N, N'-methylenebis-acrylamide. The main product in the ester synthesis of glycerin and oleic acid by this immobilized enzyme was monoglyceride, making it clear that this enzyme had high selectivity to the esterification reaction system. The conversion of the esterification was improved by control of water content in gels.
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Eiji Iritani, Yuhta Itano, Toshiro Murase
1993 Volume 19 Issue 3 Pages
536-539
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Dead-end inclined ultrafiltration is examined, using a dynamic membrane comprised of fine particles formed on the microfiltration membrane by dead-end downward filtration. The formation behavior of the dynamic membrane is described by the cake filtration rate equation in which the compressibility of the cake is taken into account. A dynamically balanced rate of filtration can be obtained by the inclined ultrafiltration technique, because the growth of the gel-cake can be significantly suppressed. If the membrane is inclined before enough cake to be exfoliated is formed, the dynamically balanced filtration rate is not influenced by the time when the membrane is inclined.
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On the Formation of Carbon Monoxide and Carbon Dioxide
Makoto Akiyoshi, Satoru Hisaki, Takashi Fukuda, Eiji Obata, Koji Ando
1993 Volume 19 Issue 3 Pages
540-543
Published: May 10, 1993
Released on J-STAGE: May 07, 2010
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The air oxidation of trace amounts of hydrogen cyanide contained in air was examined in the temperature range from 927K to 1003K. From the material balance of carbon it is found that the carbon of hydrogen cyanide was converted only to CO and CO
2. The conversion rate of hydrogen cyanide to CO was found to be slower than that of CO to CO
2. Most of the poisonous hydrogen cyanide and CO were oxidized immediately, and air containing hydrogen cyanide was made harmless. Air oxidation for the treatment of hydrogen cyanide in air is recognized to be one of the methods that enable us to fulfill environment restrictions.
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Roberto Massahiro Serikawa, Toshitaka Funazukuri, Noriaki Wakao
1993 Volume 19 Issue 3 Pages
544-548
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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Vinasse, a residue from distillation of alcohol-fermented sugar-cane juice, was converted into oil by heating at 300°C in a bomb-type batch reactor with argon or high-pressure water with/without the addition of, separately, Na
2CO
3, H
2SO
4, zeolites and FCC catalyst. The highest oil conversion (24.5 wt%) was obtained by the pyrolysis of dried vinasse in the argon atmosphere. For high-pressure conversion of aqueous vinasse, the presence of H
2SO
4 increased oil yield, while that of Na
2CO
3 decreased it. The addition of FCC catalyst was found to increase low-molecular weight components and decrease S and N contents in the oil. FCC catalyst was considered effective in the high-pressure oil conversion of aqueous vinasse.
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Hiroaki Yamauchi, Hiroshi Kaneshige, Masaki Fujimura, Yasuharu Nosho, ...
1993 Volume 19 Issue 3 Pages
549-553
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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To investigate the relationship between the staling rate of bread crumb and storage temperature (from 5°C to 40°C), white bread with/without monoglyceride was made by the straight method. The staling rate constants were determined at each storage temperature, using Cornford's model, and a model on staling as a function of storage temperature was proposed. The response of staling to change in storage temperature was calculated by computer simulation based on the proposed model. The simulated results based on the model agreed well with the experimental data.
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Hironao Ogura, Michito Kanamori, Hitoki Matsuda, Masanob Hasatani, Mic ...
1993 Volume 19 Issue 3 Pages
553-556
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
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The purpose of the study is to enhance Cao regeneration in the heat storage mode of a chemical heat pump using Ca (OH)
2/Ca0 reaction. The effect of the condensation conditions and the effect of the supplied heat temperature level to the Ca (OH)
2 particle bed on heat storage characteristics were investigated experimentally and theoretically.
The following results, were found, i) Both the reaction temperature and the reaction eqilibrium pressure were lowered by the condensation enhancement. ii) The overall reaction rate of Ca (OH)
2dehydration was accelerated and the practical operating limit temperature in the heat storage mode could be lowered.
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Kazumi Satoh, Hiromi Simada
1993 Volume 19 Issue 3 Pages
557-560
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
JOURNAL
FREE ACCESS
The power of impeller, (P
gv)
f, required to attain complete off-bottom suspension of glass spheres (average diameter 72480μm, solid concentration 25wt%) was studied for five types of impeller.
It was found that the influences of gassing varied with the impeller type. (P
gv)
f of axial-flow and mixed-flow impellers increased with gassing rate but that of radial flow impellers was practically independent of gassing rate. At low gassing rate the axial-flow impeller showed the lowest (P
gv)
f, while at high gassing rate the radial flow impeller showed lower (P
gv)
f than other types of impeller. The mixed-flow impeller was suitable for intermediate gassing rate.
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Masafumi Mochizuki, Noboru Takei, Kazumi Satoh, Takashi Akehata, Teruk ...
1993 Volume 19 Issue 3 Pages
560-563
Published: May 10, 1993
Released on J-STAGE: November 12, 2009
JOURNAL
FREE ACCESS
Values of aerated power required at upper and lower stages of a dual impeller under loading state in stirred vessels were measured with a unique method. The following points. were revealed.
1) The power of the lower stage in most dual impellers and the power of the upper stage for the impeller of largest diameter in this work were equal to that of a single impeller operating in the same condition. 2) The power of the upper stage was smaller than that expected for an unaerated impeller in a fluid of density equal to that of the gas-liquid mixture.
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