Experimental and Numerical Study of Gas-Liquid Flow in a Sectionalized External-Loop Airlift Reactor

doi:10.1016/j.cjche.2020.10.023

Abstract

Abstract: The external loop airlift reactor (EL-ALR) is widely used for gas-liquid reactions. It's advantage of good heat and mass transfer rates compared to conventional bubble column reactors. In the case of fermentation application where a medium is highly viscous and coalescing in nature, internal in riser helps in the improvement of the interfacial area as well as in the reduction of liquid-phase back mixing. The computational fluid dynamic (CFD) as a tool is used to design and scale-up of sectionalized external loop airlift reactor. The present work deals with computational fluid dynamics (CFD) techniques and experimental measurement of a gas hold-up, liquid circulation velocity, liquid axial velocity, Sauter mean bubble diameter over a broad range of superficial gas velocity 0.0024 ≤ U_G ≤ 0.0168 m·s^-1. The correlation has been made for bubble size distribution with specific power consumption for different plate configurations. The effects of an internal on different mass transfer models have been completed to assess their suitability. The predicted local mass transfer coefficient has been found higher in the sectionalized external loop airlift reactor than the conventional EL-ALR.

Key words: Multiphase reactor, Bioreactors, Computational fluid dynamic, Sectionalised external loop airlift reactor, Gas hold up, Mass transfer

摘要： The external loop airlift reactor (EL-ALR) is widely used for gas-liquid reactions. It's advantage of good heat and mass transfer rates compared to conventional bubble column reactors. In the case of fermentation application where a medium is highly viscous and coalescing in nature, internal in riser helps in the improvement of the interfacial area as well as in the reduction of liquid-phase back mixing. The computational fluid dynamic (CFD) as a tool is used to design and scale-up of sectionalized external loop airlift reactor. The present work deals with computational fluid dynamics (CFD) techniques and experimental measurement of a gas hold-up, liquid circulation velocity, liquid axial velocity, Sauter mean bubble diameter over a broad range of superficial gas velocity 0.0024 ≤ U_G ≤ 0.0168 m·s^-1. The correlation has been made for bubble size distribution with specific power consumption for different plate configurations. The effects of an internal on different mass transfer models have been completed to assess their suitability. The predicted local mass transfer coefficient has been found higher in the sectionalized external loop airlift reactor than the conventional EL-ALR.

关键词: Multiphase reactor, Bioreactors, Computational fluid dynamic, Sectionalised external loop airlift reactor, Gas hold up, Mass transfer

Shivanand M. Teli, Channamallikarjun S. Mathpati. Experimental and Numerical Study of Gas-Liquid Flow in a Sectionalized External-Loop Airlift Reactor[J]. Chinese Journal of Chemical Engineering, 2021, 32(4): 39-60.

Shivanand M. Teli, Channamallikarjun S. Mathpati. Experimental and Numerical Study of Gas-Liquid Flow in a Sectionalized External-Loop Airlift Reactor[J]. 中国化学工程学报, 2021, 32(4): 39-60.

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