| The successful performance and safety of the Very-High-Temperature Nuclear Reactors (VHTR) extremely depend on the quality of the TRISO nuclear fuel coated particles. However, the coating of the TRISO particles is delicate process and impacted by the hydrodynamics of spouted beds. Therefore, in this work, we applied advanced non-invasive measurement techniques which are gamma-ray computed tomography (CT) and radioactive particle tracking (RPT), to investigate foremost the local parameters to advance the fundamental understanding of the hydrodynamics and scale-up of gas-solid spouted beds. The CT technique has been applied to study the effects of particle density, particle size, bed size, and superficial gas velocity on the gas-solid cross-sectional distributions of spouted beds. The CT results demonstrated that the summation that operating spouted beds at stable spouting state would lead to achieving proper coating layers of the particles in the TRISO fuel coating process is not adequate. On the other hand, the RPT technique has been applied to evaluate the hydrodynamics, and mixing and segregation behavior of binary solids mixture spouted beds with particles of same size but different densities encountered in the TRISO nuclear fuel particles manufacturing process. The RPT results demonstrated that for the hydrodynamics of binary solids mixture spouted beds having particles of similar size but different densities, particle collisions by the particle-particle interaction plays an important role. At last, we evaluated the new mechanistic scale-up methodology that has been developed in our laboratory based on matching the radial profile of gas holdup at the region of the developed flow since the gas dynamics dictate the hydrodynamics of the gas-solid spouted beds. The measured local parameters obtained in this part confirm the validation of our new methodology of scale-up of gas-solid spouted beds. |
