Experimental study of cryogenic oxygen–nitrogen mass transfer characteristics on microtextured plates

Abstract

The detailed effects of microtexture on the distillation performance of the cryogenic fluids are seldom reported. In this work, sinusoidal microtextured plate was applied to carry out falling film visualization and mass transfer experiments of cryogenic oxygen–nitrogen system. The flow pattern and wetting of LN2 on the microtextured plate and the flat plate were analyzed through the recorded images. Gas-liquid countercurrent mass transfer experiments of oxygen–nitrogen system on the microtextured plate were conducted. Results show that the F-factor in cryogenic distillation operation should be lower than that of common chemical processes to avoid the deterioration of mass transfer performance. Furthermore, experiments on the effect of microtexture size on oxygen–nitrogen mass transfer performance were conducted. Results show that increasing the amplitude and decreasing the periodic length can optimize the interfacial mass transfer performance of cryogenic distillation. Finally, new mass transfer correlations for cryogenic distillation are proposed.