Hydrogen transport through interface between gas bubbling and liquid breeders

An experimental study was performed to investigate hydrogen transport under conditions of gas bubbling into the liquid breeders of Li, Pb–17Li and Flinak. Gas of H2 or high-purity Ar at 0.1 MPa was injected into the liquid breeders using an I-shape nozzle. Then, the H2 partial pressure in the cover gas under transition state was measured by a solid electrolyte sensor. Variations of the partial pressure in the exhaust gas were compared with a numerical model to describe hydrogen transfer through the bubble–liquid interface. The experimental rates of hydrogen transport in the liquid breeders were correlated in terms of a mass-transfer coefficient for the hydrogen transport under gas bubbling. The overall mass-transfer coefficient for H2 charging was compared with that for Ar purging. The coefficient for the recovery was about 10 times lower than that of the charging in the respective cases of the Pb–17Li and the Flinak.