Studies On Gas-side Mass Transfer Performance And CFD Simulationg Of Gas Flow In Mulit-liquid-inlet Rotating Packed Bed

As the core equipment of HI GEE technology,rotating packed bed?RPB?has a strong advantage in the molecular diffusion and intensifying mass transfer process,and has been used in a wide range of industrial applications.A novel rotating packed bed named multi-liquid-inlet rotating packed bed?MLI-RPB?was designed to create more than one end zone because of three rings of packing.The studies on the liquid side mass transfer in MLI-RPB have been researched,but the gas side mass transfer in MLI-RPB is lacking of detailed researches.In this paper,we use SO₂-NaOH gas film control system to study the gas side mass transfer in MLI-RPB.Besides,by using the method of computational fluid dynamics?CFD?to optimize the internal components which were proposed to improve mass transfer,which is hoped to strengthen the gas turbulence and accelerate the renewal of the film.Relying upon the method above,this paper provides the theoretical fundamental and technical support for the description of the gas phase flow field of the rotating bed and the optimization of the reactor structure.The main research conclusions are below:1.By using SO₂-NaOH system,the influence of rotor speed,gas flow rate,liquid flow rate and liquid-inlet type on the gas side mass transfer coefficient of the MLI-RPB was studied.The results show that the gas side mass transfer coefficient of MLI-RPB increases when the rotational speed,the gas flow rate,the liquid flow rate and the number of liquid-inlets increase.Besides,in the same operating conditions,the mass transfer performance of MLI-RPB is compared with that of the conventional RPB with the same rotor volume.The experimental results show that the mass transfer coefficient of MLI-RPB is higher than that of the conventional RPB.2.The 3D physical model of MLI-RPB is established according to the real size except for the packing which is described as porous medium model.As is compared,the Realizable k-? turbulence model is more suitable for the gas flow simulation in MLI-RPB than the standard k-?turbulence model.It is also found that the gas pressure drop increases with the increase of the gas volume and the rotational speed.The simulated values are in agreement with the experimental values within ±15%,so the model and simulation method are verified to be reliable.3.The 3D physical model of MLI-RPB with different internal components is established,and the five sorts of structures are simulated and analyzed by the previous method.The quantitative analysis shows that the five sorts of structures have no effect on the whole bed flow field,but because of inner components there is more vortex which can enhance the aerostatic turbulence.Meanwhile,the qualitative analysis shows that among the sorts of inner components,the third structure?+60°,-60?component perturbs the gas flow largest,and is more conducive to gas film renewal.Finally,no inner component,?0 °,0 °?component and?+ 60 °,-60 °?component are compared by the mass transfer experiment to verify the simulation and analysis before.The results show that the mass transfer coefficient can be increased by 10%-20%because of the inner components.