In the design and analysis on air washer system with pure water, we need to estimate the vaporliquid equilibrium of related systems. In this study, the vapor-liquid equilibrium for dilute aqueous solutions of volatile weak electrolytes is examined by numerical calculation and experimens. Equilibrium composition in vapor and liquid phase is calculated for NH₃-CO₂-H₂O, SO₂-CO₂-H₂O and NH₃-SO₂-CO₂-H₂0 systems. Total solute concentration, pH and vapor phase partial pressure of NH3 and SO2 are determined in dilute aqueous solutions from 10^-6 to 10^-3 mol/kg-H₂O in 23°C. Equilibrium composition is predicted and is in good agreement with experimental results in each multicomponent aqueous system. As a result, ionic dissociation and Henry's constants quoted from Edwards' correlation are available even in dilute aqueous solutions of volatile weak electrolytes. These results allow estimate of ionic dissociation and vapor-liquid equilibrium in dilute aqueous solutions of volatile weak electrolytes.

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A new technology using a vertical round tube filter with a wire mesh wall is developed, in order to separate ice crystals from the ice slurry generated in freeze concentration. The ice slurry discharged from an ice generator with rotating scrapers was introduced into the filter. The concentrate was filtered radially through the wire mesh filter and the ice cake was discharged from the upper exit in the form of an ice packed column with weight fraction of 0.50 to 0.53. The mean diameter of ice crystals was increased by 2 to 4 times during filtration. The increase in size is mainly due to contact and fusion of ice crystals.
The concentrate contained in the ice cake was successfully recovered into a vacuum collector connected to a column filter packed with the ice cake by displacing the concentrate with fresh water fed to the column. As compared with ordinary centrifugal filtration, the residual concentration of solute among ice crystals is as low as a few 10 mg/l and also the loss of the concentrate is negligible.

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A new ion exchange resin operation system which can treat fermentation broth without any pretreatment is studied. In a conventional fixed bed column pretreatment such as membrane or centrifugal separation is required in order to prevent the clogging of bacteria in the resin layer inside. However these processes require higher capital investment and lower the yield.
The new method solves these problems by treating ion exchange resin as slurry. No problem is observed in pilot scale experiments using lysine fermentation broth. The bacteria do not clog the resin phase, and elute is not contaminated, even if the bacteria concentration of the feed fermentation broth is very high (10 vol%). In addition, it is found that the amount of washing water in the new method is less than that of the conventional method.
A simple numerical simulation model is also proposed and evaluated. The numerical value expresses good agreement with the experimental value, and it is proved that this model can be used for optimization of process design.

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Models for sensory evaluation of beer and the beer brewing process were constructed using a fuzzy neural network (FNN). A new method for optimal model selection using a genetic algorithm and a SWEEP operator method was compared with a conventional method using the parameter increasing method. As the result, the new method was useful for the optimal model selection by simplifying the model structure, improving the reliability of fuzzy rules, and accelerating the calculation speed (about 10 times as fast as conventional method) for constructing the model with high accuracy. The percentage of correct answers of the sensory evaluation model is 92%. The important variables are selected as the input variables, and the obtained fuzzy rules in modeling coincide well with knowledge data bases acquired by process operators. and it is proven that the obtained FNN models are adequate.

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The reverse osmosis (RO) technique employed in desalination systems requires the pumping up of seawater above its osmosis pressure mechanically. Development of a desalination system utilizing the high static pressure of the deep sea is investigated. Experiments of seawater desalination were carried out in the East-China-Sea using a device in which a spiral-type RO membrane module was installed. It is proven that fresh drinking water can be obtained from seawater utilizing the static pressure of the deep sea, without the use of electric power. A numerical analysis was conducted to predict the amount of fresh water produced. Analytical results show sufficient agreement with experimental results.

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The hydrodynamic characteristics and extraction performance of a multistage liquid-liquid extraction column with a novel impeller which is equipped with static mixers on a disc are study experimentally.
The holdup of the dispersed phase varies along the height of the column. The holdup at the first stage of the column increases with increasing dispersed phase flow rate. It decreases in the region of low flow rate of the dispersed phase and high impeller speed, and increases via a minimum value in the region of high flow rate of the dispersed phase and heigh impeller speed, and increases in the region of low impeller speed with increasing continuous phase flow rate. It also increases in the region of low flow rate of the continuous phase, and decreases via a maximum value in the region of high flow rate of the continuous phase with an increase in impeller speed. In the other stages, the holdup increases with increasing dispersed phase flow rate and impeller speed. However, the effect of continuous phaseing flow rate on hold up is not significant. The dispersed flooding flow rate increases with increase continuous phase flow rate and then decreases via a maximum value with the impeller speed.
The theoretical stage number per unit column height increases with increasing total flow rate of dispersed and continuous phase, and then decreases via a maximum value with the impeller speed. The performance is evaluated by the theoretical stage number per unit column height and is somewhat higher compared with those of other extractors in the literature. The meshwire setted on the stator rings has a remarkable effect on extraction efficiency, and is found to have the function of settling of dispersed phase.

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Fe₂O₃-SiO₂ which removes H₂S and COS from hot coal gas, was prepared. The characteristics of reduction are studied using simulated coal gas that was synthesized by an air blown gasifier.
Fe₂O₃-SiO₂ was only reduced to oxides in which the oxygen atomic ratio to iron (R_O/Fe) was 1.0-1.3 at 1%-5% steam concentrations in the temperature range of 623 K-723 K. It is estimated that oxides were mixtures of Fe₃O₄, Fe_1-xO and iron silicate. This evaluation indicates that an amorphous SiO₂ prevented the formation of Fe, Fe₃C and carbon.
The formation of Fe₂SiO₄ starts at 773 K, and Fe is converted completely into Fe₂SiO₄ above 823 K. Such formation of Fe₂SiO₄ causes large decrease in specific surface area. This result indicates that sintering of Fe₂O₃-SiO₂ is caused by the formation of Fe₂SiO₄ above 773 K. It is suggested that Fe₂O₃-SiO₂ should be used as a desulfurization material below 773 K.

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For an absorption heat pump system, the authors have proposed a controller design method, in which the dynamical behavior of the system is approximated by a linear differential inclusion so that the nonlinearity of the system can be taken into account in controller design. However, this method has two problems. Namely, the controller obtained by this method tends to be high-gain and the closed-loop system with the controller tends to have a small decay rate. In this paper, we propose an improved controller design method, in which some constraints are added to the controller specification to cope with the problems mentioned above. The necessary and sufficient conditions for the design problem with multiple specifications are solved by the algorithm that we developed recently.

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2-butanol was emulsified with several kinds of surfactants and esterified by indirect electrolysis using a redox couple I⁺/I^- as a mediator. For any kind of surfactant, relatively large amount of carboxylic acid was by-produced besides the ester. The ester yield is affected by kind of surfactant and concentration. When anionic surfactant SDS and nonionic surfactant Triton X were used, ester yield increased regularly with an increase in their concentration to about three times as much as that obtained without a surfactant. In contrast, the carboxylic acid yield shows a maximum against surfactant concentration and maximum values are dependent upon the kind of surfactant used. The changes in electrolysis behavior with addition of surfactants are explained roughly in terms of HLB values of the surfactants and change in the rate-controlling step.

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The influences of limestone addition and staging of combustion gas on the emission reductions of SO₂, NO and N₂O are experimentally examined for coal combustion in a bubbling fluidized-bed where CO₂/O₂ combustion system is applied. An Australian bituminous coal was burnt by a mixture of a recycled flue gas and oxygen in a 0.158 m i. d. and 3 m high combustor. Tsukumi limestone crushed to sizes 1 to 3 mm was used for sulphur removal. The results obtained in CO₂/O₂ combustion are compared with those in conventional once-through air combustion.
Sulphur removal efficiencies in CO₂/O₂ combustion at a bed temperature ranging from 1090 to 1150 K are much higher than those in air combustion. It is confirmed from a model analysis based on mass balance that such higher SO₂ removal efficiency in CO₂/O₂ combustion is mainly produced by extension of mean contacting/reaction time between limestone particles and SO₂ due to flue gas recycling into the combustor. Two-stage combustion depressed NO_x and N₂O emissions in CO₂/O₂ combustion, as well as in air combustion. Compared with single-stage combustion, emissions are reduced to less than 2/3 when the ratio of primary/total oxygen flow rate is approximately 0.8. Thus, we can say that CO₂/O₂ combustion is an excellent system not only for CO₂ recovery, but also for emission reductions of SO₂, NO_x and N₂O.

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Both upward and downward cake filtration experiments are conducted under constant pressure conditions, using calcium carbonate slurry. The effects of particle sedimentation on filtration performance are examined. The filtration rate in upward filtration becomes much larger than that in downward filtration because of the effects of particle sedimentation. A theoretical model has been developed to describe the effects of particle sedimentation on properties of both upward and downward cake filtration. The filtration rates in both upward and downward filtration are evaluated using both compression-permeability cell data and batch sedimentation test data, on the basis of modern filtration theory. In addition, a method is described to determine the value of the coefficient of constant pressure filtration from both upward and downward filtration experiments. This study reveals that sedimentation can have a profound effect upon filtration behavior in upward and downward cake filtration of a particulate suspension.

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A safe operating region in which the state of a complete mixing type reactor moves spontaneously towards a stable steady state without manipulative action is determined by the tracking function analysis.
The tracking function, which is a linear combination of temperature and concentration of reactant, is displayed with a straight line on the phase plane and the line moves with time in the direction predicted by the derivative of the tracking function with respect to time. If straight line segments which correspond to tracking functions are assemble to form a closed polygon around a stable steady state on the phase plane and each segment moves towards the steady state as time passes, then the polygon manifests a boundary of safe operating region.
Safe operating regions of the reactor in which dehydration and decomposition of methanol proceed simultaneously are shown with a tetragon and a heptagon around the stable steady states.

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Ash from waste incineration and coal combustion processes contains various kinds of toxic heavy metals. It has been proposed that the elution of these metals is possibly restricted by solidification of the ash with hydrate formation. Typical hydrates of ettringite and monosulfate are formed from lime, alumina and gypsum, which are often contained by the various kinds of wastes. Thus, it is expected that mixing various wastes in adequate ratis restricts the elution of these metals. In the present study, first of all, the mixtures of the pure reagents with various ratios were cured and X-ray diffraction analysis was conducted for the formed solids. The intensity of the diffraction peak of ettringite increases with increasing ratio of gypsum to lime, while that of monosulfate has a maximum at a mixture ratio of 3 : 4 : 3 for lime, alumina, and gypsum. Secondly, the eluted amount of lead from the solid hydrates with addition of lead was evaluated by the standard method for soil environment. It is found that the elution of lead is suppressed under conditions of ettringite formation and lower pH value of the effluent than around 12.

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In suspension polymerization of styrene, it was discussed how the solid powder prepared under the various conditions affects the polymer particle size distribution. In the experiment, calcium carbonate powder was used as the stabilizer, which was prepared at different temperatures. The shape and the diameter of calcium carbonate prepared are extremely different.
It is found that the addition of calcium carbonate prepared at 20°C formes larger polymer particles than at 70°C.

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Numerical simulations are conducted for the natural convection heat transfer in a narrow gap between two horizontal plates in air. The lower plate is an infinite plate with a circular heating zone. The upper one is the bottom of a vertical cylinder, which is placed right above the circular heated plate and kept at room temperature.
A set of Navier-Stokes equations and an energy equation are analyzed for a variety of combinations of gap clearance and Rayleigh number. The calculated average heat transfer are shown to be in good agreement with the experimentally obtained ones reported in the previous paper. From the obtained isotherms, stream lines and local Nusselt numbers, it is found that two types of convection appear in the gap space according to the conditions of Rayleigh number and gap clearance one is a simple convection due to the single renewal flow which replaces heated air with ambient air and the other is a combined convection due to several vortex flows and the renewal flow. Furthermore, it is also found that the flow rate of each flow controls the rate of heat transfer from the limited area which is covered by each flow. From this fact, the validity of the previously proposed heat transfer correlation is briefly discussed.

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Deformation analyses for a rubber-covered roll and a diminutive V-shaped groove carved on the roll are performed in order to predict the coating weight on a strip in squeeze roll coating processes.
The distribution of contact force on the roll is estimated from the deformation analysis on the base of an influence coefficient method, taking into account the deflection of the roll axis and the surface indentations of the inner steel sleeve and the rubber. The surface indentation of the rubber is derived from an elastic solution in a semi-infinite body, i. e., the difference of displacement between the surface and a referential point in the semi-infinite rubber. The position of the reference point in the rubber is determined from the value multiplied by the rubber thickness of the roll by a compensation coefficient depending on the load acting on the surface.
The relation between the deformation of a groove and the load acting on the groove is analyzed by the finite element method as the elastic contact and large deformation problems under the plane strain condition. The coating weight is predicted on the basis of the deformed groove.
An experiment is conducted to verify the accuracy of our prediction model of coating weight, and the relations between the load and the approach of the roll centers, the contact width of the rolls, and the coating weight are examined. The experimental results are in good agreement with the analytical results, and our prediction model is confirmed to be reasonable.

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Measurement of particle size distribution in gas-particle flow is very important. Conventional methods require a complicated classifier like the Andersen Stack Sampler or other particle size measuring instruments. In order to simplify the measurement of particle size distribution, an advanced method employing backward sampling has been proposed. The method measures the particle size distribution without a classifier, and is applicable to melted particles and droplets. There are, however, a few studies regarding the classification efficiency of backward sampling, and the equation that predicts the classification efficiency of backward sampling, has not been proposed.
In this study, the classification efficiency of backward sampling is numerically and experimentally investigated. Particle trajectories near the sampling probe are calculated to estimate the classification efficiency. Furthermore, experiments with dusts emitted from combustion of pulverlized coal and kerosene are carried out. The concentration ratio (concentration in sampling probe/concentration in main flow) is affected mainly by the particle size, the main flow velocity, and the sampling velocity. The concentration ratio decreases with increasing the main flow velocity and the particle size, but it increases with the sampling velocity. The concentration ratio is determined by the inertia parameter and the velocity ratio (main flow velocity/sampling velocity). An equation, which estimates the relationship among them, is proposed.

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The heat generation behavior of liquid-liquid heterogeneous reactions when stirring is instantly re-started after phase separation is investigated using a reaction calorimeter. An empirical equation of the heat release rate is introduced on the assumption that the transfer rate of reactant to the continuous phase and the reaction rate are balanced after re-start stirring.
As experimental values of the maximum heat release rate under various experimental conditions of sulfonation of toluene and neutralization of acetic acid and sodium hydroxide are applied to the proposed equation, a good correlation is found between the maximum heat release rate and the size of the interfacial area for each reaction. Since the mass transfer coefficient of the neutralization obtained by this equation agrees well with the literature value, it is found that the mass transfer rate can be determined by measurement of the heat release rate with a reaction calorimeter.
Furthermore, the heat release rate vs. time curves after re-start stirring under the various conditions are calculated using the proposed equations of each reaction, and the calculated results show good agreement with the experimental values when the dispersed phase is completely dispersed into the aqueous phase.

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We propose indices of sharpness, S_s^* and representative diameter, D_s^*, for evaluation of grinding proceeding, both of which are defined through an integrated area along cumulative frequency curves undersize of a particle diameter distribution.
We investigate dynamic changes of particle diameter distribution with these indices. It was found that these indices, S_s^* and D_s^* can express more accurately the subtle characteristics of the grinding process, which can not be described sufficiently with the grinding indices, S_s and D_s, defined through the Rosin-Rammler approximation.
Subsequently, we evaluate the grinding proceedings for various kinds of rotor types and grinding media for the continuously stirred bead mill, with S_s^* and D_s^*. It was found from the evaluation that the continuous annular-stirred mill, on the Spike mill, can even grind talc particles, but the cumulative diameter distribution becomes broader. S_s^* and D_s^* can express more accurately that the Spike mill, with the narrower clearance between rotor and mill vessel wall, using smaller zirconia beads can grind calcium carbonate particles most satisfactorily.

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A simple technique for the flow property analysis of a power law fluid with the terminal velocity of a falling body in a viscous fluid has been developed for process control of a chemical plant. A falling needle viscometer was used as the experimental equipment, and a slender hollow cylindrical needle of which both ends are hemispherical was applied to falling body. As the fluid model of laminar flow, the fluid behavior between the falling needle surface and container wall was analyzed, and Stokes type equation was introduced for the calculation. Shear stress and shear rate at the surface of each needle were calculated with the terminal velocity of the falling needle and the density difference between the sample fluid and needle.
Analysis of the flow property in power law fluid was carried out in accordance with the following procedure.
(1) Measurement of density difference between fluid and needle.
(2) Measurement of terminal velocity of falling needle in fluid.
(3) Calculation of shear stress and shear rate at needle surface.
(4) Determination of parameters in constituted equation.
(5) Drawing of constituted flow curve.
As for this analysis, U_t- (ρ_s-ρ_f) and log U_t-log (ρ_s-ρ_f) diagrams which were described by use of the experimental data, are very similar to that of τ-γ and log τ-log γ diagrams, respectively. It is found that the flow curve configuration for a power law fluid can be predicted from the data of terminal velocity and density difference. As a result of experiments of some model fluids, it is verified that the method using a viscometer presented here could be effectively applied to high viscosity fluid and that the application is available for such Power law fluid as polymer solution and suspensions containing fine particles. Further, an analytical method by use of a computer system is also presented for the fluids.

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Separation experiments of nickel and cobalt are carried out by a porous glass packed column using terdentate diethylenetriamine and quadridentate triaminotriethylamine as eluent at 298 K. The influence of dentate number of amine on separation efficiency of metals is investigated referring to the results of separation experiments for unidentate ammonia and bidentate ethylenediamine reported before. Increasing dentate number of amine decreases the amount of metal adsorbed, promotes the elution of metal and enables us to separate nickel and cobalt at lower concentration of amine, and to completely recover cobalt. The optimum value of pH for separation is 8 for uni to terdentate amines and 6 to 7 for quadridentate amine. These results show that the elutions of metals are under the control of two kinds of the factors, viz., adsorption of metal by amine complex ion and desorption of metal by free amine.

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To predict the behavior of particles in a large scale rectangular fluidized bed with immersed vertical tubes, a simulation model is proposed by modifying the previous model which has proved to be effective for simulating the spatial distribution of bubbles and particle circulation. The distribution of particle velocity is also calculated. The importance of considering the proper arrangement of immersed vertical tubes is stressed, since the immersion of vertical tubes into the bed has a significant effect on the flow patterns of particles.

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An aqueous solution is obtained as permeate through a polyimide membrane from a 1-hexanol/ water biphase mixture with higher aqueous fraction than 0.52 under conditions of 0.15 MPa of pressure and 40°C. Continuous separation of the aqueous phase from the mixture can be performed at 0.6 of aqueous fraction and 0.15 MPa, and a stable aqueous phase flux of 5.39 × 10^-6 m³· m^-2· s^-1 obtained.

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In this research, the embedding degree of individual fine particles coated by rotational impact blending is measured by image analysis and the relationship among the operational conditions is investigated. As a result, the embedding degree is enhanced with an increase in the peripheral velocity of the rotor blade, and the treatment time and with decrease in the fine-particle diameter.
Moreover, the accessible void area of the coarse particle surface is related to embedding degree and the surface uniformity in our former paper for coating with fine particles of multi sizes.

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