气液并流向上填充鼓泡塔液体混合特性的研究

在内径为165 mm气液并流向上填充鼓泡塔中采用示踪法考查了表观气速、表观液速、液体黏度、填料大小等因素对液体轴向混合特性的影响。根据实验结果得出:Peclet准数随表观液速的增加而增大,轴向返混程度减小,而随表观气速或液相黏度的增加而Peclet准数略有减小,轴向混合程度增加。同时,填料的引入明显减少轴向混合程度,随着填料直径的增加,Peclet准数明显减少,轴向混合程度增大。根据实验结果,关联了实验范围内Peclet准数的计算式,为填充鼓泡塔反应器的设计与放大提供了一定的指导作用。

低气液流速下三相固定床的传质特性

在低气液流速下对三相固定床气液并流向上和并流向下操作过程的传质特性进行了对比研究。分别采用物理吸收法和化学吸收法测定液相体积传质系数k_L^a与气液相际比表面积a,利用电容层析成像系统测定了床层持液量,并分别使用直径为1.9,4.0,9.3 mm的球形填料进行实验,考察颗粒的尺寸效应。结果表明:k_L^a和a均随气液流速增大而增大,其中向上流动受气液流速影响均很明显,而向下流动受液速影响较大。颗粒尺寸越小,k_L^a与a越大。相同气液流速下,向上流动相比于向下流动,k_L^a高出45%,a高出75%。采用量纲分析法拟合实验数据,得到k_L^a与气液相Reynolds数、液相Weber数之间的关联式。根据稳定气泡理论模型,得到气液并流向上过程a的预测关联式。

气液向上或向下并流固定床动持液量测定

In this work,at a pressure of 2.0 MPa and room temperature,the effects of gas and liquid flowrates, liquid viscosity and operation pressure on the dynamic liquid holdup were investigated in a downward flow and upward flow fixed-bed reactor. With an air-water-solid packing system, experimental results show that the dynamic liquid holdup increased with an increases of liquid mass flowrates.It decreased with an increasing of gas volume flowrates and porosity of packed bed. It was also shown that there was no large effect on dynamic liquid holdup with an increase of liquid dynamic viscosity. The correlations of dynamic liquid holdup was also given under these two kinds of operation.