Gas-liquid and gas-liquid-solid mass transfer model for Taylor flow in micro (milli) channels: A theoretical approach and experimental proof

New theoretical approach to model Gas-Liquid and Gas-Liquid-Solid mass transfer for two-phase Taylor flows in milli and microchannels is proposed. The main idea of the proposed mathematical model is to take into account not only diffusion but the convection inside of liquid slugs caused by circulation within Taylor vortices and the convective transport from the film surrounding the bubble to the slug induced by the film movement. For that aim a three-layer model elaborated earlier by Abiev (CEJ, 2013) is used to decompose the liquid slug onto three interacting layers. Diffusion within the film around bubbles and the transit film belonging to the slug, as well as diffusion from the bubble caps was included in the model as well. Experimental data of Bercic & Pintar (CES, 1997), Butler et al. (CHERD, 2016; IJMF, 2018) and Haase et al. (TFCE, 2020) used for proof have shown quite better coincidence with the proposed model than the other available models. Special tests without convective term have demonstrated much less accuracy with the experimental data confirming the huge role of convection in the overall gas-liquid and gas-liquid-solid transport. The correlation between frequency of circulations within Taylor vortices and overall gas-liquid mass transfer coefficient found recently (Abiev et al., CEJ, 2019) was confirmed by use of Bercic & Pintar (CES, 1997) data. In the frame of the moving bubble the velocity of the transit film equals to the absolute value of two-phase velocity. That is why the convective term significantly influences the total mass transfer in the film and overall gas-liquid transport as well.