Wall to liquid mass transfer in packed a

This study investigates the wall-to-liquid mass transfer coefficient, kw, in packed and fluidized bed systems with gas-liquid concurrent up flow. The objective is to understand the behavior of kw in different configurations, specifically for a coaxially immersed tube and a column wall. We conducted experiments measuring kw across various conditions, including open-pipe liquid flow and gas-liquid two-phase up flow, alongside single liquid flow in packed and fluidized beds. Our results indicate that in three-phase fluidized beds, kw increases with rising gas flow rates and exhibits a maximum related to liquid flow rates, differing from liquid-solid fluidized beds and aligning closer to gas-liquid two-phase up flow conditions. For packed beds, kw also positively correlates with both liquid and gas flow rates. Notably, we found a unified equation correlating kw values across all examined systems based on energy dissipation rate per unit mass of liquid. Furthermore, an analogy is established between wall heat transfer and wall mass transfer in these multiphase flow contexts, reflecting the overall importance of wall-to-liquid mass transfer in chemical reactor design and operation.