The behavior of adhesive fine powder on a vibrating wall was analyzed using the distinct element method. The moving elements were spherical particles 10μm in diameter, and the adhesive force was taken into account as an interaction force between the contact bodies. When vibration of 20kHz started, the particles piled on the wall were immediately broken down in the gravitational field and changed into small agglomerates which were moving randomly. The state of small agglomerates was controlled by vibrational dispersion and agglomeration, which could be evaluated by a particle contact number. The number increased with decreasing vibrational acceleration and/or increasing adhesive force. Furthermore, two conflicting phenomena related to the vibrating powder, i. e., high flowablility and close packing, were explained by the strength of the adhesive force.

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The numerical simulation of the velocity and stress fields for a flowing powder which consists of uncountablly numerous particles is one of the most difficult things to do. We have numerically simulated these fields of flowing powder using the Smoothed Particle (S. P.) method based on the relationships of the stress-strain rates obtained by D. E. M.. In the S. P. method, the partial differential equations, which are the governing equations of the flow fields, are transformed to ordinary differential equations which are Lagrangian-type equations of particle motions. The numerical analysis of ordinary differential equations is much easier than that of partial differential equations. Moreover, Lagrangian analysis is suitable for the description of the characteristics of discrete particles.
The calculated results of the velocity and stress fields in a two-dimensional rectangular hopper are compared with the measured values obtained under nearly the same conditions, and a fairly good agreement among them is obtained. These results show that the S. P. method is an effective tool to simulate the various flow fields of powders which consist of uncountably numberous particles.

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Shear tests have been made on a variety of powders-silica, flyash, precipitated calcium carbonateover a range of temperatures from room temperature to 800°C. The results show that the flowability of powders becomes lower at higher temperatures because of increase in the inter-particle adhesive force. At the same time, the chemical and physical characteristics of powders vary at high temperatures.
Therefore, the effects of temperature on the shear properties of fine powders are affected not only by particle size, chemical and the physical properties of powders but also by the measuring atmosphere.

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The purpose of this work is to clarify the density segregation of binary particle mixtures due to vertical vibration. The bed, a mixture of glass and lead particles, is vertically vibrated under less than 120Hz. It is found that an inverse density segregation, where the heavier component comes upward, is observed after a homogeneous convection with increasing displacement amplitude. The mixing-segregation map for the vibrating parameter is made. It is also found that there is a critical velocity amplitude A_VC=0.1m/s for the transition from mixing to separation.

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