Research On Hydrodynamics And Mass Transfer Performance Of SCA Type Highly Efficient Structured Packing

The development and application of new highly efficient structured packing has been a hot research topic in the field of separation at domestic and abroad.New structured packing with excellent performance has been emerging.Based on the analysis of mass transfer theory,this paper optimizes and improves the existing structure of structured packings,and develops a new type structured packing-SCA type high-efficiency wire mesh corrugated packing which takes the hydrodynamic and mass transfer performance both into consideration.The structure of SCA type packing is unique in that it breaks through the limitation of a single linear change:the ends of the corrugated line are two small vertical lines,the middle line is at an angle of 300 to the vertical direction.The two arcs with the opposite concavity and the central angle of 600 are symmetric with respect to the center,and they are tangent to the straight line at both ends,and connected to the middle fold line.The whole packing has a special configuration in which straight and curve line alternates,and has the advantages of many typical packings such as straight type packing and Impulse packing.The comprehensive performance of three SCA-type packings with large specific surface area(700,800,1000 m2·m-3)was measured by cold-model experiments with water-air-oxygen as medium.Compared with the performance of traditional CY type packing,the results show that the dry tower pressure drop of SC A type high efficiency packing is reduced by 32%on average;the wet tower pressure drop is reduced by 38.5%on average;the liquid flooding speed is 19.5%higher on average;the height equivalent to a theoretical plate(HETP)is reduced by an average of 22%.These comparative data verify the excellent overall performance of the SCA type packing,and the effect is obvious in improving the mass transfer efficiency,reducing the packing pressure drop and increasing the operational flexibility.Using the classical and universal hydromechanics model,three kinds of SCA type fillers with different specific surface area were correlated and fitted,and the correlation between dry pressure drop and flooding gas velocity model with good correlation and high precision was obtained,and can be used to calculate the relevant performance values of SCA type packing under different operating conditions.Starting from the mechanism of packing pressure drop,and based on the characteristics of its own structure,combined with reasonable model assumptions and process analysis,this paper establishes new pressure drop models for describing and predicting the dry pressure drop and wet pressure drop of SCA type packing.The relative deviation,which is between calculated values and experimental values of the new models,through calculation,is within the allowable range.The new pressure drop models can accurately predict the pressure drop of SCA type packing under different operating conditions,which provides theoretical guidance for subsequent industrial applications.