| Energy saving and intensification of distillation has been a hot topic in the field of chemical engineering scholars,the development of novel mass transfer elements is the most important.Regular geometric structure,stable gas-liquid channel,uniform,showing an excellent performance with high-throughput,low pressure drop,high efficiency make structured packing the most widely used mass transfer element in distillation.Si C foam and carbon foam have the advantages of large specific surface area,high porosity,easy control of the pore diameter and corrosion resistance,which have aroused wide attention and application of the scholars in the field of distillation,and have good prospects for development.Our research group applied these two materials above to the production of distillation element,and a variety of novel foam corrugated packings were developed.In order to explore the effect of structural characteristics of foam corrugated structured packing on its performance,in this paper,three kinds of Si C foam corrugated structured packings SFP-500Y-D5,SFP-500Y-D3 and SFP-500X-D3 and two carbon foam packings CFP-500X and CFP-500W were selected.The hydrodynamic properties of three kinds of SiC foam packings were measured by using air-water in a plexiglass tower with a diameter of 600 mm under atmospheric pressure.Mass transfer efficiency?HETP?of all five packings were measured by total reflux experiments in a column with 310mm diameter at atmospheric pressure,using a mixture of n-heptane and cyclohexane.The results show that the SFP-500Y-D3 packing with smaller pore size?3mm?shows a larger dry and wet packing pressure drop compared with SFP-500Y-D5,and the flood velocity is reduced by about 9%,mass transfer efficiency increased by about 12.6%.Compared with CFP-500W packing whose corrugation angle is 15°,CFP-500X?30°?packing with larger corrugation angle shows a larger we pressure drop,and the mass transfer efficiency is improved by about36.8%when F-factor is in the range of 0.341.48?m/s?·?kg/m3?0.5.Foam structured packing exhibits a higher separation efficiency than traditional metal packing.The study of different liquid distribution shows that the trough-plate distributor with strong resistance to liquid entrainment and stable liquid distribution is more favorable for the performance of foam packing than nozzle.In this paper,the diffusion characteristics of the liquid on foam corrugated packing with different structural characteristics and materials were studied by using fluorescence UV imaging technology and image data processing et al.Results show that under same corrugation angle and compression ratio,the smaller the pore size,the better the diffusion performance of the packing sheet,but this is also accompanied by a decrease in capacity.The flow rate is positively correlated with the vertical diffusion velocity and lateral diffusion distance of the liquid on the packing sheet,and has no significant effect on the diffusion angle and diffusion area in most cases.The larger the inclination angle is,the smaller the diffusion angle of the liquid is,which leads to the decrease of the vertical diffusion velocity,the increase of the lateral diffusion distance and the diffusion area.Under same conditions,the diffusion performance of the liquid on SiC foam packing sheet is better than that of carbon foam packing sheet,with better lateral distribution and larger mass transfer area.Maybe an explanation why the mass transfer performance of SiC foam corrugated structured packing is better than carbon foam one from the perspective of mass transfer area.In general,the foam corrugated sheet has excellent liquid diffusion performance,less ditch phenomenon,liquid film diffusion is obvious,a good liquid distribution capacity,can provide a larger gas-liquid contact area.In general,the foam corrugated sheet has excellent liquid diffusion abilities,less groove flow,obvious liquid film diffusion and good liquid distribution.All the factors above can provide a larger gas-liquid contact area. |
PDF Full Text Request