Study on control of oxygen concentration in lead–bismuth flow using lead oxide particles

Performance of mass exchanger type oxygen control system for the control of oxygen concentration in a flowing lead–bismuth (Pb–Bi) was investigated in a low temperature region of a Pb–Bi circulation loop. Oxygen dissolved and diffused from lead oxide (PbO) particles into the melt or oxide precipitated in the mass exchanger. The electromotive force (EMF) of an oxygen sensor installed in a high temperature region of the loop indicated the changes of oxygen concentration in the loop with the temperature changes of the PbO particles reasonably. The measured EMF agreed well with theoretical result obtained using ΔGPb–Bi–O equation0 in the Nernst equation. The expression of oxygen solubility in the melt in the mass exchanger, Cs, was derived from the data as log Cs = A + B/T, where the constant A ranged from −4000 to −4600, and the constant B ranged from 1 to 3.5 depending on the temperature of the melt.