Development And Performance Research Of Advanced 3D Structured Packing With High Gravity

As the core component of the high gravity device,the structure and characteristics of the packing play an important role in the hydrodynamics and mass transfer performance of the high gravity device.The high-speed rotating packing realizes multiple shear and coalescence of the liquid,increasing the degree of liquid turbulence and improving the surface renewal rate,effectively reducing the size of liquid element and mass transfer resistance,increasing the interphase contact area,thus strengthening the mass transfer process.Therefore,the fine structure design and characteristic size determination of packing are of great significance to the application performance of high gravity technology.Through in-depth study to strengthen the process of the layered cross-flow rotating packed bed,combined with wire mesh packing for liquid dispersion effect is strong and plate type packing dynamic balance outstanding advantages,such as using 3ds Max software and 3D printing technology,build a fine packing structure and a lot of other new structured packing of gas liquid channel,and design the unique structure of spiral vane.The liquid phase is dispersed and aggregation multiple times when the effective gas diversion is realized,and the end effect zone is increased,the degree of gas-liquid turbulence is intensified,the mass transfer performance is improved,the pressure drop is reduced,and it has the advantages of good dynamic balance and convenient installation and maintenance.The gas-phase pressure drop performance of 3D structured packing was investigated in a layered cross-flow rotating packed bed with air-water as the experimental system.The effects of high gravity factorβ,empty bed gas velocity u,spray density q and stators with and without packing on gas-phase pressure drop performance were investigated.Under the same operating conditions,3D packing showed excellent pressure drop performance,which was 41.3%lower than wire mesh packing in gas phase and 31.2%lower than pall ring packing on average.The pressure drop of wet bed is 23.6%higher than that of dry bed,and the influence of air velocity on the pressure drop of wet bed is the most significant,followed by the high gravity factor.The pressure drop of the rotating bed with and without stator packing has the same change rule,and the gas pressure drop with stator increases by about 20.9%compared with that without stator.Compared with the literatures,the gas pressure drop of the new 3D packing is significantly lower than that of Pall ring packing and nickel foam packing,indicating that the structured gas communication channel of the new 3D packing can effectively reduce the gas pressure drop.The effects of high gravity factorβ,empty bed gas velocity u,spray density q and stators with or without packing on the mass transfer performance of 3D structured packing were studied with SO₂-Na OH,a typical gas film controlled chemical absorption system,and the gas volume mass transfer coefficient k_ya_e was measured.Under the same operating conditions,the mass transfer performance of 3D packing is comparable to that of wire mesh packing and 28%higher than that of pall ring packing.The results show that the gas-liquid channel and spiral blade structure designed in 3D packing can achieve the shear and coalescence of gas-liquid,and can further improve the degree of gas-liquid turbulence and enhance the mass transfer efficiency.The presence of stator will affect the mass transfer performance of the rotating packed bed.The volumetric mass transfer coefficient of gas phase with stator is 57～72%higher than that without stator.It is found that the most obvious factor affecting the mass transfer coefficient is the empty bed gas velocity,followed by the spray density,and the influence of the high gravity factor is not obvious.Through literature comparison,it is found that the mass transfer performance of 3D structured packing is similar to that of screen packing,and it has the advantages of lower gas phase resistance,large material handling capacity and low energy consumption.By analyzing the pressure drop and mass transfer performance of the 3D structured packing,it is found that the 3D structured packing can significantly reduce the pressure drop and achieve good mass transfer effect.At the same time,through the study of the stator,it can be seen that the stator is of great significance to the performance of the layered cross-flow rotating packed bed.In this paper,the results can provide packing improvement has important guiding significance to the development and equipment,the packing design from macro to micro,from packing gas liquid channel design itself,as a new super gravity packing design provides a new idea and design ideas,promote supergravity technology application in the field of strengthening mass transfer,better economic benefits.