Marangoni convection and its influence on the mass transfer in the liquid phase were investigated. Marangoni convection was visualized using laser Schlieren technique. Orderly polygonal convection patterns and random interfacial turbulence were observed. The effect of Marangoni convection on the mass transfer rate was studied by desorbing ethanol from aqueous solution in the falling film. The experimental results show that Marangoni convection can speed up the surface renewal and enhance the mass transfer rate in the liquid phase. The liquid mass transfer coefficient can be enhanced by as much as 3 folds. The corresponding empirical correlations are given in terms of the mass transfer enhancement factor. Furthermore, in considering the Marangoni effect, the conventional mass transfer correlation was modified. The differences between the values predicted by the correlation and the experimental data are within ±8.20/0 and the average difference is 4.20/0.
The separation efficiency of a representative sheet metal structured packing (Mellapak 350Y) in experimental columns (0.15?m i.d.) is presented at high-pressure and total reflux distillation conditions. N -butane and n -pentane is used as the testing system.Pressures span the range of 0.7-1.9?MPa.With the increase of F -factor,the HETP values decrease slightly in the loading area at all test pressure but increase before flooding point.By comparing the experiment data with the predictions of SRP model,it is found that SRP model performance deteriorates at a high pressure.
