Estimation Of Erosion By Lead-Bismuth Eutectic Flow Through Packed Bed Of Lead Oxide Spheres In Mass-Exchanger

Lead Bismuth Eutectic(LBE)is considered as a suitable choice for coolant in Acceleration Driven Systems(ADS)due to its favourable thermos-physical,material and chemical properties.However,fast reactors having Lead-Bismuth Eutectic(LBE)as primary coolant require control of dissolved oxygen activity for protection of structural materials and for avoiding oxygen build-up in the coolant.The concentration of oxygen in LBE should not only be above the dissolution limit of the protective oxide layer present on the structural materials but also it should be lower than the solubility limit of oxygen in LBE to avoid lead oxide precipitation.A lead oxide mass exchanger(PbO MX)can be used to avoid excess oxidation and solid oxide formation within the system.The mass exchanger(PbO MX)comprises of a packed bed of mechanically stable lead oxide spheres randomly arranged in a cylindrical vessel.Alumina spheres are placed before and after PbO layers for development of velocity profile.Oxygen is provided by mass exchanger through the dissolution of packed bed of lead-oxide spheres in coolant.The flow of LBE through PbO spheres cause erosion.When oxygen concentration in LBE is saturated then erosion becomes major cause of PbO weight loss in mass exchanger.This research is focused on estimation of erosion caused by LBE flow via numerical simulation.The process involved Computational Fluid Dynamics as tool for analysis.The main steps involved include pre-processing,solving and post-processing,Erosion is a complex phenomenon that depends on many factors.So,a parametric study was also carried out to see effect of particle velocity,particle diameter and particle concentration on erosion rate.The simulations for this research was carried out in ANSYS Fluent and results showed that erosion is directly proportional to particle size and particle concentration.However,erosion seemed to be dependent on particle size for values of lower range only.