Abstract
Free convection ion transfer at a vertical flat plate electrode is studied both theoretically and experimentally for a dilute solution system of K3Fe(CN)6-K4Fe(CN)6 with KOH supporting electrolyte. The numerical results of the ion concentration and velocity profiles are very similar to those of the temperature and velocity profiles for free-convection heat transfer. The slight dependency of the ion transfer rate on bulk concentration, obtained from the numerical result, is confirmed experimentally. To correlate the experimental data of the ion transfer rate, a conventional estimation equation of the characteristic densification coefficient is proposed.
β0=βk4Fe(CN)6-βk3Fe(CN)6-O.5βKOH
By using this equation, the experimental data are correlated almost exactly by the correlation equation for free-convection heat transfer.
In addition, it is confirmed from the numerical result on the density difference in boundary layer that the analogy between ion and heat transfers holds well in the non-equimolar solution.
