In order to classify fine particles in slurry continuously, a horizontal type water elutriator with electro potential is newly developed. The experimental classification performance was compared with the numerical calculation. Test particles used were pure silica particles with the mass median diameters of 3.5 and 2.5μm.
The effects of inlet flow rate, slurry concentration, applied electro-potential and the shape of inlet on the classification performance were also studied. The classification accuracy increased by applying the electro-potential and the cut size decreased with an increase in the electro-potential. The classification performance with a three-layer inlet was higher than that with a two-layer inlet.
The experimental data agreed well with the numerical calculation. It is further shown that the 50% cut size was about 1μm for a relatively short time, and the newly developed water elutriator is, therefore, effective for the classification of fine particles in slurries.

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This paper is concerned with a newly developed measurement technique of particle flow-rate in gas-solids pipe flow based on the static electrification of particles. The method is found to be feasible to detect the flow-rate as small as 0.5g/s for large alumina particles of 0.3mm in mass median diameter. Here we investigated the effect of sensor vibration on the detection sensitivity to obtain the fundamental data for practical applications of the sensor in various particulate processes such as sand blasting. The jet tests with alumina particles were carried out using a vibration exciter at various frequencies and amplitudes. According to the experiments, it was found that the detection sensitivity increases with the vibration and the sensor can be applied even when the acceleration of vibration is as large as 30G. It was also found that the resonance of the sensor vibration has no significant influence on the measurement of particle flow-rate.

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Fluidized bed medium separation (FBMS) was applied to separate objects with a small specific gravity difference by precisely controlling the apparent specific gravity of gas-solid fluidized bed with binary particle systems. The binary systems of particles with various specific gravities and diameters were employed, and the apparent specific gravity of fluidized bed, g_fb and the dispersion, Δg_fb, were measured by changing the bulk volume fraction of heavier particle, V_hp, and the superficial air velocity, u₀. It was found that g_fb can be controlled by V_hp and u₀ because g_fb varies with the total mass of particles and the bed expansion. On the other hand, since Δg_fb is determined by the extent of segregation of fluidized particles and the fluidization intensity, Δg_fb decreases with reducing the extent of the segregation and the vertical fluctuation of fluidized bed surface. The experimental results showed that practical fluidized conditions for FBMS are in the range of g_fb≈0.5-3.8 and Δg_fb≤0.1. Under these fluidized conditions, plastics with a small difference in specific gravity (0.04-0.24) were almost completely separated at the top and the bottom of the fluidized bed.

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In this paper, latest development on the effective utilization processes of wood powder is expounded. First, effective pulverization techniques with a vibration mill and the pulverized wood powder characteristics are explained. Second, the biomass utilization processes using the wood powder, such as gasification process, combustion process and liquefaction process are discussed. Highly reactive wood powder as a starting material in these processes leads to high performance of process. Finally, the wood biomass powder utilization system is introduced for the practical application. The system is a combined process, which produces heat, electric power and new materials through the gasification, combustion, liquefaction and other processes of wood powders.

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Design of grain boundaries is indispensable for the development of new functional materials fabricated from nano-particles. The structural property of the grain boundary is the dominant factor for determining the physical and chemical phenomena, and the interfacial region of the grains serve as ionic transport and chemical reaction fields. In this report, computer simulations of ionic conduction and hydrogen reaction at the interfaces are illustrated. The simulation technique is a useful tool for designing functions of materials made of many grains.

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