Hydrodynamic And Mass Transfer Behavior Of A Novel Structured Packing

Structured packing has been widely used in industrial processes, especially in vapor/liquid contacting devices, due to its large load capacity, low pressure drop and high efficiency in mass transfer, and has a tendency of replacing the plate column. As a result, it is of great significance to industrial practice that high-effect structured packing can be developed on the basis of deep researches on the vapor/liquid flow and mass transfer mechanism inside the structured packing tower.In this work, the history and recent research focus of structured packing are presented in the first place. Meanwhile, brief introductions about the liquid film flow and vapor/liquid mass transfer mechanism are also provided and a novel structured packing is briefly introduced.The novel structured packing is developed on the basis of the traditional ripple packing. The openings on the novel structured packing that is leading difference from the traditional ripple packing, can lead the liquid film to the other side of the structured packing piece ,therefore the area of liquid film is enlarged and renewed ,which is benefit of the mass transfer.One focus of this paper is to conduct detailed measurements on its hydro-dynamics and mass transfer performance. Another focus is to compare this new structured packing with the traditional 350 ripple packing for the reason that the former is modified on the basis of the latter.This tower in experiment, with a diameter of 384mm, includes liquid distributor, packing section (height: 1.2m; Num: 6) and gas distributor. The air-water system is used as the experimental medium. During the experiment, pressure drop and liquid loading of the structured packing are tested. Experimental results indicate that the pressure drop of the novel structured packing is 30~40 percent higher than that of the traditional 350 type .The liquid loading of the novel 350X is 10~20 percent higher than that of the traditional 350X. The liquid loading of the novel 350Y is 4 percent higher than that of the traditional 350Y. On the other hand, the pressure drop of the novel 350X is 40 percent lower than that of the traditional 350Y,but the liquid loading of the novel 350X is identical with that of the traditional 350Y. The mass transfer performance of this new structured packing is obtained by investigating the process of carbon dioxide-water solution desorption inside the structured packing tower. By virtue of the carbon dioxide concentration at the top and bottom of the tower, the height of mass transfer unit can be acquired and mass transfer efficiency can also be further calculated. Experimental results indicate that the efficiency of the mass transfer of the novel structured packing is better than the traditional 350 type . The efficiency of the mass transfer of the novel 350X is 10~20 percent higher than that of the traditional 350X. The efficiency of the mass transfer of the novel 350Y is 5 percent higher than that of the traditional 350Y.While the efficiency of the mass transfer of the novel 350X is identical with that of the traditional 350Y .Detailed analysis of the experimental results mentioned above indicates that the novel 350X structured packing with openings can take the place of the traditional 350Y,nevertheless the pressure drop of the former is lower than that of the latter. As a result, in future study, the hydrodynamics and mass transfer performance of newly proposed structured packing characterized by openings and deflectors might be improved by changing its geometric parameters, such as inclination angle, the size of the opening, the percentage of openings and so on.