Computational Fluid Dynamics Simulation In Rotating Packing Beds

The high gravity rotating packed bed is a mass transfer device that enhances the gas-liquid mass transfer process through the centrifugal force formed by high-speed rotation.It makes full use of the transfer mechanism,reaction mechanism and relevant balance characteristics of the system to enhance the mass transfer efficiency while also strengthening the speed of chemical reaction process.At this stage,flue gas desulfurization,denitration,wastewater treatment,dust removal,ammonia removal Liquid membrane separation and preparation of nano materials.However,due to the limitations of the fine and complex structure in the system and the large gas/liquid velocity in the flow field,it is difficult to make a qualitative and quantitative analysis of the flow field in the system.On the other hand,the lack of research on mass transfer principles in the system restricts its wide application in industry.Computational fluid dynamics uses mature computer technology to discretize the control equations needed in the analysis process.The calculated results can be used to quantitatively and qualitatively analyze and study the flow field characteristics in the high gravity rotating packed bed system,and can modify the theory of actual flow.Compared with experimental techniques,computational fluid dynamics is not only unable to be limited by the size of parameters,but also has the advantages of less interference from the flow field,low operation cost,and high efficiency.The change process of various parameters,fluid flow routes,etc.can be clearly presented in the numerical calculation results,which can further study the gas-liquid flow problems in the complex flow field.In this paper,computational fluid dynamics simulation is used to explore the gas-liquid flow field patterns at different levels in the high gravity rotating packed bed system under various conditions.The research object focuses on the high gravity rotating packed bed.In the research process,computational fluid dynamics technology and modeling software are used to establish a reasonably simplified three-dimensional physical model of the body.RSM turbulence model is compared with the standard k-εWith the combination of the models,the packing is regarded as a porous medium material,and the porous medium model is used to simulate and analyze the gas-liquid flow field in different parts of the engine block.It provides theoretical guidance for the industrial application and development of the high gravity rotating packed bed and the simulation of the internal flow field.The research contents of this paper are as follows:(1)The effects of different rotating speeds on the turbulent dissipation rate,turbulent kinetic energy,turbulent viscosity and internal relative pressure at different positions in the hypergravity rotating packed bed were studied.In the low rotating speed range,the turbulent kinetic energy at different parts of the body of the hypergravity rotating packed bed increased with the increasing rotating speed,and in the high rotating speed range,the turbulent kinetic energy,turbulent dissipation rate and turbulent viscosity reached the maximum at 2000 rpm.(2)The effects of different intake air volumes on the turbulent dissipation rate,turbulent kinetic energy,turbulent viscosity and internal relative pressure at different positions in the hypergravity rotating packed bed were studied.With the increase of intake air volumes,the turbulent kinetic energy and turbulent dissipation rate in the middle part of the rotor weakened from 173 m2/s2 to 246 m2/s2,and the turbulent kinetic energy and turbulent dissipation rate in other positions increased to about 250m2/s2.The turbulent viscosity at both sides of the packing fluctuates around 0.02m2/s3,while the turbulent viscosity at the middle of the packing decreases from 0.035m2/s3 to 0.02m2/s3 and then tends to be stable with the increase of air intake.With the increase of air intake,the overall pressure drop decreases first and then tends to be stable.(3)The effects of different liquid feeding rates on the turbulent dissipation rate,turbulent kinetic energy,turbulent viscosity and internal relative pressure at different positions in the high gravity rotating packed bed were studied.With the increase of liquid feeding rates,the turbulent kinetic energy,turbulent dissipation rate and turbulent viscosity of the liquid reached the minimum when the liquid feeding rate was7L/min,and the maximum pressure was 270 Pa.The study shows that the packing of the high gravity rotating packed bed can reduce cyclones,strengthen the disturbance of gas-liquid flow field,make the liquid redistribute and enhance gas-liquid contact,and strengthen gas-liquid mass transfer.Figure [43] Table [4] Reference [84]...