The vertical pneumatic conveying of granules was performed experimentally in order to investigate the effect of spiral flow on the damage of granules. The spiral flow used in this study is weak and the maximum swirl number is 0.03 when the mean air velocity is 10m/s. It was found that granules are transported along the pipe wall in the spiral flow and the spiral flow is effective in reducing the damage of granules at lower air velocity. Numerical simulations showed that the number of collisions between granules and pipe wall in the spiral flow is larger than that in the axial flow but the kinetic energy of granules that come in collision with the pipe wall is smaller in the spiral flow than in the axial flow at lower air velocity. It is inferred that the spiral flow makes the granules move along the pipe wall reducing the kinetic energy of granules to below the threshold of granule strength for breakage.
Organic-inorganic nanocomposites have been made by hybridization of silica nanoparticles in a thermoplastic resin using a melt extrusion method. We found that uniform dispersion of nanoparticles in the resin can be attained by the treatment of nanoparticle surfaces with an organic compound and the modification of polystyrene resin prior to mixing as well as the optimization of screw design of a twin screw extruder. Since the domain size of silica nanoparticles in the resin is smaller than the wavelength of visible light, the obtained composites are transparent in visible region, which is important for industrial applications.
The present work studied the effects of NaOH concentration on the crystal structure and the reaction rate of zeolite synthesized from a mixture of fly ash and silica powder with a hydrothermal treatment method. As a result, it is found that lower NaOH concentration favors the formation of phillipsite in the generated zeolite by reducing the formation of hydroxysodalite and that the reaction rates monotonously increase with NaOH concentration. It is shown that the crystal structure of generated zeolite depends on factors other than the dissolution rates of silicate ion and aluminate ion from fly ash into NaOH aqueous solution. The fraction of silica powder required for the selective formation of phillipsite increases with the NaOH concentration, while the treatment time decreases with it.