Showing papers in "Kona Powder and Particle Journal in 1984"

The Role of Adsorbed Water on Adhesion Force of Powder Particles

Abstract: Adhesion forces generated at a contact point between spherical and plate specimens of potassium halides, commercial soda-lime glass and Pyrex glass were estimated by using an electrobalance, and adsorption isotherms of water vapor and methyl alcohol on these samples were also measured. The thickness of a liquid bridge and the pressure at which a capillary condensation occurs for the first time have been investigated using porous glasses each of which has a monodispersed pore radius. The following conclusions have been deduced from the comprehensive comparison of the obtained results. The adhesion forces under low and high water vapor pressures are suggested to be ascribed to hydrogen bond and liquid bridge, respectively. A marked increase of adhesion force observed in the pressure range 0.6 < P/P0 < 0.85 is due to a transformation from hydrogen bond to liquid bridge and due to a change in the physical property of condensed liquid. The thickness of the liquid bridge at P/P0 = 0.6 is presumed to be 29-37A

Reduction of Power Consumption in Pneumatic Conveying of Granular Materials through a Pipeline

Abstract: Pneumatic conveying of granular materials generally requires a great deal of power consumption in spite of its excellent advantages which are not obtainable with other transport methods. The purpose of this study is to examine the behavior of pneumatic conveying systems from both theoretical and experimental perspectives and find out an optimum way of reducing power consumption. It is concluded that the application of vibration to pipes or bends is effective for this purpose. In addition several improvements to obtain economic conditions are discussed.