3D UNSTEADY MULTIPHASE SIMULATION OF URANIUM TETRAFLUORIDE PARTICLE FLUORINATION IN FLUIDIZED BED PILOT

摘要

This paper investigates Eulerian simulation approach of uranium hexafluoride production in fluidized bed pilot. Mass transfer is modeled by using the shrinking particle model. The model successfully predicts expected amount of uranium hexafluoride. As heat transfers with wall are neglected, temperature increases within the reactor and there is no gradient in wall-normal direction of reactor. External diffusion model of reactive gas around particle is developed. Effect of fluorine diffusion within nitrogen is found to be negligible under the simulation conditions. Moreover, inter-particle radiative heat transfer between particles of dense phase in the bed is investigated in the frame of Rosseland approximation.