折流式旋转床气液比表面积的实验研究及CFD模拟

doi:10.16085/j.issn.1000-6613.2017.05.011

摘要/Abstract

摘要： 气液比表面积对折流式旋转床（RZB）的传质起到关键的作用。本文采用NaOH溶液化学吸收混合气体中CO₂的方法对折流式旋转床的气液比表面积进行了研究，通过计算流体力学（CFD）技术来模拟转子内液体的流动行为。分析转子转速、气体流量和液体流量对气液比表面积的影响。结果表明：折流式旋转床的比表面积在100~350m²/m³范围内，折流式旋转床的气液比表面积随液量的增大而增大，随气量的增大明显增大，随转速的增加先缓慢增大后迅速增大。CFD模拟表明，随液量的增加，动静圈之间的液滴数量明显增多，并且静圈上更多的表面被液膜覆盖；随气量的增大，更多的液体被碎成细小的液体，液滴的数量成倍增加；随转速的增大，动圈施加给液体的剪切力和离心力增大，液体被更好地分散，并且离开动圈的液滴尺寸变得更小。RZB与其他类型填充旋转床（RPB）的气液比表面积进行对比，发现RZB的比表面积低于分段进液式RPB、常规不锈钢金属网RPB、镍泡沫填料RPB、新型多个叶片转子RPB，接近于板式填料和挡板PRB。

关键词: 折流式旋转床, 化学吸收, 气液比表面积, 计算流体力学, 流动

Abstract: Gas-liquid effective interfacial area play a key role in rotating zigzag bed (RZB). The gas-liquid effective interfacial areas in a RZB were studied with chemical absorption of CO₂using NaOH solution in the mixed gases. The flow behavior of liquid in the rotor was simulated via CFD. The effects of rotor speed,gas flow and liquid flow on the effective specific surface area were studied. Experimental results showed that gas-liquid effective interfacial area in RZB is about 100-350m²/m³. Gas-liquid effective specific surface area increases with the increase of liquid and gas volume. It increases with the rotor speed slowly at first and than rapidly afterward. CFD simulation indicated that between the rotational baffle and stationary the droplet volume increased significantly and more static ring surface is covered by liquid membrane with the increase of fluid. Along with the increase of gas,the more liquid is broken into tiny droplets. Along with the increase of rotational speed,moving coil increases imposed on the centrifugal force and shear force of liquid. Liquid is better dispersed. Moving-coil droplet size becomes smaller. The values of a_e of RZB rotor are lower than those of the multiliquid-inlet rotating packed bed (RPB),conventional RPB with stainless steel wire mesh,RPB with nickel foam packing and RPB with novel rotor of blades and multiple packing,and are close to the PRB equipped with blade packings and baffles.

Key words: rotating zigzag bed, chemical absorption, gas-liquid effective interfacial area, computational fluid dynamics(CFD), flow field

中图分类号:

TQ021.4

张斌, 李育敏, 耿康生, 计建炳. 折流式旋转床气液比表面积的实验研究及CFD模拟[J]. 化工进展, 2017, 36(05): 1635-1641.

ZHANG Bin, LI Yumin, GENG Kangsheng, JI Jianbing. Experimental and CFD simulation on gas-liquid effective interfacial area in rotating zigzag bed[J]. Chemical Industry and Engineering Progress, 2017, 36(05): 1635-1641.

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