Hydrodynamics of Geldart Groups A, B, and D Materials during Jet Cup Attrition

Particle attrition can be detrimental to fluidized bed applications. The jet cup test is commonly used to assess the relative tendency to attritbute gaps in the understanding stymie quantitative links between the lab-scale jet cup test and commercial-scale operation. In this study, high-speed video imaging was performed to understand better the particle hydrodynamics and kinetic energy distribution of Geldart Groups A and B particles in a conical jet cup, since particle-particle and particle- wall interactions are positively correlated with attrition rate. Particle tracking velocimetry (PTV) was used to measure the particle velocity and change in the particle velocity due to collisions. The results of these measurements were also compared with computational fluid dynamics- discrete element method (CFD-DEM) simulations. A mechanistic attrition model can be developed by measuring the kinematics of particle-wall interactions and how particles are recycled back into the jet. This represents a first step to creating this understanding by demonstrating the relative contributions of particle-particle and particle-wall collisions from experiments and the use of compartment models for understanding how particles cycle through regions of high collision probability. Once this mechanistic model is in place, quantitative comparisons between jet cup results and commercial fluidized bed operations can be made.