| Rotating packed bed has special advantages in chemical engineering process intensification, and many scholars have made great achievements in its industrial application results, but the internal flow field of fluid mechanics performance remains to be further research. In this paper, we regard the actual packing as a porous medium, and use FLUENT commercial software with the porous medium model. According to the rotating bed size in laboratory, varieties three-dimensional physical models of different structures of the rotating packed bed were established. At the same time, we choose the suitable turbulent flow equation for the porous medium model. Numerical simulations on gas phase and gas-liquid two phases are made. The main research results are as follows:(1) Standard k-ε turbulence model is more close to the experimental data contrasted with Realizable k-s model in the porous medium model. The gas pressure drop decreases as the packing porosity increases. Due to the rotation of the packing, the gas velocity reaches the largest in the outside of the packing and decreases gradually on the radial orient.(2) Simulating the gas flow rate and rotating speed on the influence of gas phase pressure drop, the results show that the gas pressure drop rises as the gas flow rate and rotating speed enhancing, the average pressure drop error between the simulation and the experiment is14.7%. In the porous medium model, the turbulence kinetic energy in housing section is greater than the packing area. When the outside of the packing is fixed, the pressure drop is smaller as the packing becomes thicker, When the inside of the packing is fixed, the pressure drop is larger as the packing become thicker. The pressure drop increases when the wire-mesh is arranged in the housing section. There is a large velocity gradient along the wire-mesh and the wall, and the flow rate of the gas in cavity decreases gradually on the radial orient.(3) A three-dimensional physical model of multi-liquid-inlet rotating packed bed was built, and we research the pressure drop from gas flow rate and rotating speed. When gas flow rate rises, the average pressure drop error between the simulation and the experiment is about20%. In addition, the average pressure drop error between the simulation and the experiment is about10%as rotating speed increases. From the contours we can see that the speed between the packing and the middle of the packing is different.(4) Different structures of RPB were designed, such as radial inlet, tangential inlet, radial inlet with baffle, radial inlet with pore baffle. We simulate the pressure drop and gas distribution in the above four structures.Pressure drop of RPB both rises when gas flow, rotating speed increases, but the pressure drop of tangential inlet is the lowest. The radial maldistribution of the radial gas inlet is the highest near the outside edge of the packing. It indicates that the amplitude of pressure fluctuation varies greatly. The radial inlet with pore baffle has a better gas distribution than radial inlet with baffle. At most case, the tangential inlet is the best design for gas fed, the gas distribution can be ordered as flows: the best is the tangential inlet, the second is the radial inlet with pore baffle, the third is the radial inlet with baffle,the worse is the radial inlet. In practical engineering, when the gas flow rate is large, radial inlet is often used due to tangential inlet needing complex mechanical processing conditions. In order to decrease maldistribuion, radial inlet with pore baffle can be used.(5)When gas-liquid two phase countercurrent flow, droplets inject out from the injection source, the speed increases after entering the packing and decreases from the outside of the packing. The droplets disappear when it encounter he wall and the speed is not zero. Wet bed pressure drop is smaller than dry bed, and wet bed pressure drop increases with the gas flow rate and rotating speed. |
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