A clouded bubble-based mass transfer model for the simulation of gas–solid bubbling fluidization

Bubble mesoscale structures play a critical role in the transport process in bubbling fluidization. A bubble-based multiscale method has been developed to modify the conventional model. Whereas the effect of the circulating gas flow features around bubble, called “bubble cloud”, is usually neglected. The bubble cloud is an essential way to transport the reactant species from the bubble phase to the bed. In this work, the impact of the bubble cloud in the mass transfer process is considered. The bubble cloud is taken as the inter-phase based on the multi-scale resolution of the bubbling fluidized bed system and a clouded bubble-based mass transfer model is established. The proposed model is incorporated in the two-fluid model to simulate the ozone decomposition process in 3D bubbling fluidized beds. It is proven that the results using the proposed mass transfer model can give a better agreement with the experimental data than the homogeneous model. The role of the bubble cloud is significant in the mass exchange process.