The effect of inlet design and developing flow on local mass transfer in electrolyzers

Abstract

The mass transfer performance of electrolyzers can vary significantly depending on the type of inlet that is used. Furthermore, significant local effects can occur if the flow is not distributed well by the inlet. In this work, these effects are investigated using segmented electrodes. With a tube inlet, the formation of a jet results in regions of low and high mass transfer. With a conic inlet, significant flow channeling to the sides of the electrolyzer is observed. These local effects were reduced by using a divider inlet, the addition of a calming section, or a turbulence promoter. The type of inlet also determines the flow regime: with the extended conic configuration the flow is developed laminar, whereas with the tube inlet the flow is developing turbulent. The cross-sectional area ratio of the inlet to the channel was found to be an important parameter in predicting the local mass transfer behavior.