Flow and mass-transfer model of new countercurrent gas-liquid scrubber

doi:10.11949/j.issn.0438-1157.20170655

Abstract

Abstract:

The flow-mass transfer characteristics of a new countercurrent gas-liquid scrubber were investigated through cold model experiment. The results indicated that different gas-liquid flow patterns in the scrubber could be obtained under different operating conditions. Both the volume of the highly efficient mass-transfer and the desorption rate under the bubble flow presented the higher values comparing with those under other two flow patterns. Combining the experimental results with theoretical analysis, a two-zone flow-mass transfer model which can estimate the mass-transfer of the scrubber was established based on its characteristics of rapid renewal on gas-liquid surface and highly turbulent bubble flow. The structural/operating features of the scrubber were also considered. The proposed model divided the whole gas-liquid impinging area into two zones, including the rotating jet-flow zone and the high-efficiency mass-transfer zone. Then the relationships of desorption rate to L/G as well as ω were discussed by using the model. The computed results by this model match well with the experimental under different operating conditions and it can be used for engineering design purpose.

Key words: gas-liquid flow, scrubber, mass transfer, desorption rate, surface renewal

摘要：

通过冷模实验对一种新型气液逆流式洗涤器流动传质特性进行了考察。实验结果表明，在不同的操作条件下，洗涤器内气液两相流动会呈现出不同的流型。其中，洗涤器在泡沫流状态下的高效传质段体积和解吸率的数值均较大。将实验结果与理论分析相结合，依据其气液接触表面更新极快、形成高度湍动泡沫流的特点，提出了一种基于该洗涤器结构和操作特性、可以预测洗涤器传质效果的“两段式”流动-传质模型。模型将洗涤器内气液作用区分为两个区段：旋转射流段和高效传质段。利用该模型分析了解吸率与液气比L/G和旋流比ω的变化关系；结果表明，在不同操作条件下，该模型的计算结果与实验数据吻合较好，可供工程设计参考。

关键词: 气液两相流, 洗涤器, 传质, 解吸率, 表面更新

CLC Number:

MAN Changzhuo, FAN Yiping, FAN Hanwen. Flow and mass-transfer model of new countercurrent gas-liquid scrubber[J]. CIESC Journal, 2018, 69(2): 642-649.

满长卓, 范怡平, 范瀚文. 新型气液逆流接触洗涤器流动-传质模型[J]. 化工学报, 2018, 69(2): 642-649.

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