An Analysis of the Chaotic Motion of Particles of Different Sizesin a Gas Fluidized Bed

摘要

The dynamic behavior of individual particles during the mixing/segregation process of particlemixtures in a gas fluidized bed is analyzed. The analysis is based on the results generated fromdiscrete particle simulation, with the focus on the trajectory of and forces acting on individualparticles. Typical particles are selected representing three kinds of particle motions: a flotsamparticle which is initially at the bottom part of the bed and finally fluidized at the top part of thebed; a jetsam particle which is initially at the top part of the bed and finally stays in the bottom defluidizedlayer of the bed; and a jetsam particle which is intermittently joining the top fluidized andbottom de-fluidized layer. The results show that the motion of a particle is chaotic at macroscopicor global scale, but can be well explained at microscopic scale in terms of its interaction forces andcontact conditions with other particles, particle-fluid interaction force, and local flow structure.They highlight the need for establishing a suitable method to link the information generated andmodeled at different time and length scales.