An advanced evaluation of spouted beds scale-up for coating TRISO nuclear fuel particles using Radioactive Particle Tracking (RPT)

A set of dimensionless groups has been proposed in the literature by He et al. (1997) to scale-up gas-solid spouted beds while maintaining their hydrodynamics similarity. The literature reported studies do not provide conclusive assessments about this methodology. Therefore, in this work, we have applied an advanced non-invasive Radioactive Particle Tracking (RPT) technique for the first time to evaluate such scale-up methodology by measuring the local solids velocity, normal and shear stresses and the turbulent kinetic energy. The axial and azimuthal averaged radial profiles of solids velocity, normal stresses, shear stresses, and turbulent kinetic energy illustrate that the similarity of the hydrodynamics has not been attained when the proposed set of dimensionless groups has been matched using two sizes of spouted beds of 0.076 m and 0.152 m and sets of operating conditions. The conclusion is consistent with the recent reported findings by measuring cross sectional distribution and radial profiles of solids and gas holdups along the bed height using gamma-ray computed tomography and by the limited point measurements of solids velocity and holdup using optical fiber probe. It is clear that local measurements of hydrodynamic parameters are essential for detailed assessment of scale-up methodologies. The presented results of our work in terms of the components profiles of the particles radial velocities and turbulent parameters are also valuable for benchmarking computational fluid dynamics codes and models.