Influence of electrolyte concentration on holdup, flow regime transition and local flow properties in a large scale bubble column

33rd UIT (Italian Union of Thermo-fluid dynamics) Heat Transfer Conference

物理学;力学

Besagni, Giorgio^1 ; Inzoli, Fabio^1

Politecnico di Milano, Department of Energy, Via Lambruschini 4a, Milano

20156, Italy^1

关键词: Critical concentration;    Electrolyte concentration;    Flow regime transition;    Inner diameters;    NaCl concentration;    Radial position;    Superficial gas velocities;    Transition regimes;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/655/1/012039/pdf
DOI  :  10.1088/1742-6596/655/1/012039

学科分类：力学，机械学

来源: IOP

【 摘 要 】

We experimentally investigate the influence of the electrolyte concentration on holdup, flow regime transition and local flow properties in a large scale bubble column, with air and water as working fluids. The column is 0.24 m inner diameter, 5.3 m height and the air is introduced by a spider sparger up to a superficial gas velocity of 0.2 m/s. The influence of five NaCl concentrations are investigated by using gas holdup and optical probe measurements. The gas holdup measurements are used for analysing the flow regime transition between the homogeneous and the transition regime and the optical probe is used for studying the local flow characteristics at different radial positions. The presence of NaCl - up to a critical concentration - increases the gas holdup. The increase in the gas holdup is due to the inhibition of the coalescence between the bubbles and, thus, the extension of the homogeneous regime. The results are in agreement with the previous literature on smaller bubble columns.