折流式旋转床气液比表面积的实验研究及CFD模拟

发布时间：2018-11-25 15:45

【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CO_2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100~350m~2/m~3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。
[Abstract]:The specific surface area of gas-liquid plays a key role in mass transfer of (RZB). In this paper, the gas-liquid specific surface area of a baffled rotating bed is studied by means of chemical absorption of CO_2 from mixed gas by NaOH solution. The flow behavior of liquid in rotor is simulated by computational fluid dynamics (CFD) technique. The effects of rotor speed, gas flow rate and liquid flow rate on the specific surface area of gas and liquid are analyzed. The results show that the specific surface area of the zigzag rotating bed is in the range of 100~350m~2/m~3. The gas-liquid specific surface area of the baffled rotating bed increases with the increase of the liquid content, and increases obviously with the increase of the gas content. CFD simulation shows that the number of droplets between the static and static rings increases obviously with the increase of the liquid volume, and more surfaces are covered by liquid film on the static ring. With the increase of gas volume, more liquids are broken into small liquids, and the number of droplets increases exponentially. With the increase of rotational speed, the shear force and centrifugal force applied to the liquid by the moving ring increase, the liquid is better dispersed, and the size of the droplet leaving the moving ring becomes smaller. RZB is compared with the gas-liquid specific surface area of the other type of filled rotating bed (RPB). It is found that the specific surface area of RZB is lower than that of RPB, conventional stainless steel mesh RPB, nickel foam filler RPB, new type multi-blade rotor RPB, is close to that of plate packing and baffle PRB..
【作者单位】：浙江工业大学化学工程学院浙江省生物燃料利用技术研究重点实验室;
【分类号】：TQ051.1

【相似文献】