Fuel mixing in bubbling fluidized beds: an experimental and numerical study

Paper in proceeding, 2015

In this paper we study experimentally and numerically the behaviour of inert and fuel particles in a bubbling gas-solid fluidized bed. We use the Particle Image Velocimetry (PIV) technique to obtain detailed information on the dynamics of the inert particles. Furthermore, a digital image analysis technique is applied to track an illuminated tracer particle in the bed, in an attempt to reproduce the behaviour of the fuel particles. The results of the experimental work are presented in the form of the averaged velocity vectors of the inert and tracer particles. In addition, a numerical investigation is carried out where the inert bulk phase is modelled within the Eulerian-Eulerian framework and large fuel particles are tracked in a Lagrangian frame of reference. The stresses in an inert phase are modelled using the visco-plastic constitutive law (the so-called µ-rheology approach). The assumption that the inert particulate phase behaves as a visco-plastic fluid leads to a correct prediction of the movement of the fuel particles in the bed.