Effect of Particle Shape on Packing Properties during Tapping

In order to investigate the effects of particle properties including particle shapes on the packing characteristics during tapping, the changes of void fraction, ε, in a tapping bed were measured by using particles with various shapes, sizes and densities. The particle shapes were characterized by a pair of shape indices, i. e., circularity, φ, and smoothness, ζ, through the image analysis of randomly-oriented particles. As a result, it was found that the changes of void fraction with tapping number, n, is expressed by the following simple equation; (ε-εf)/(εo-εf)=exp(-knq), where εo and εf are the initial and the final void fractions in the packed bed. Furthermore, the effects of particle properties, φ, ζ, as well as particle diameter, dp, and density ρ on εo and εf and on the parameters k and q were quantified by the multiple regression analysis of experimental results.