Mathematical Modelling of Erosion in a Three Dimensional Fluidised Bed

A three dimensional hydrodynamic model of a fluidised bed combustor (FBC) based on the Eulerian-Eulerian method has been developed to simulate bubble and solids motion in a rectangular fluidised bed with an immersed obstacle. This paper presents preliminary results from a study of erosion on immersed tubes in a three dimensional fluidized bed with the purpose of predicting local erosion rates around a single square and round tube. The CFDS-FLOW3D hydrodynamic model as developed by Witt and Perry was adapted to predict the solids motion within the bed and the modified Finnie erosion model is coded in for predicting erosion rates. The significance and necessity for three dimensional erosion models is investigated. In comparison with the two dimensional results, the computations show improvement in the flow pattern and erosion rates.