Complete off bottom suspension of a multi-modal distribution

of solids in a stirred tank

Presenter: Inci Ayranci

 

 

This study aims to examine the complete off bottom suspension conditions for turbulently mixed slurries with high solids loadings in stirred tanks. The work is carried out both experimentally and computationally. In experiments, combinations of glass beads, bronze powder and ion exchange resin were tested with two types of impellers: an A310 and a PBT. These experiments showed that less dense particles act as a carrier fluid for dense particles. That is, if a slurry is composed of two types of particles, one large and dense, the other one small and less dense, the less dense particles help in suspending the dense particles. As a consequence, large and dense particles can be suspended at lower impeller speeds with less power consumption. Computationally, the start-up of mixing of glass beads and bronze powder slurry is replicated successfully with large eddy simulations, using a Lattice Boltzmann scheme.