Modelling the erosion of immersed tubes in bubbling fluidized beds using MP-PIC simulations

This work presents a novel erosion model, named Weighted Impact Energy Erosion Model (WIEEM), to predict the erosion of immersed tubes in bubbling fluidized beds. The model, applied to brittle materials, estimates the material loss caused by the kinetic energy of impinging particles, assuming that a fraction of this energy is used to detach small portions of the target material. Calculations comprise the hardness, the fracture toughness of the target, the particle volume fraction, and the particle impingement velocity. The WIEEM also includes an impact angle weighting function derived from previous studies in the literature. To perform erosion predictions, the hydrodynamic data were obtained by means of validated Multi-Phase-Particle-In-Cell (MP-PIC) simulations. MP-PIC numerical simulations have arisen as a Eulerian–Lagrangian methodology alternative to CFD-DEM for mid and large-scale fluidized bed models. Despite its potential, only qualitative studies on erosion have been conducted. To the authors’ best knowledge, this study is the first attempt to couple quantitative erosion models to MP-PIC simulations.

The WIEEM, using two different impact angle weighting functions, was compared with previous experimental results and erosion models available in the literature to assess their qualitative and quantitative accuracy. The angular weighting of Finnie (WIEEM-FN) resulted in an improved accuracy of maximum erosion rates prediction. In average, WIEEM-FN deviations rounded 21%, whereas Finnie’s erosion model was roughly 23%. Nonetheless, the weighting function of Oka (WIEEM-Oka) reproduced better the shape of the circumferential profile of erosion.