Development of gas-solid fluidization: particulate and aggregative

Since its inception in 1921, fluidization has gone through rapid and successful developments. The early fluidization theory was proposed based on uniformly suspended single particle flow, represented by Lewis and Elgin. Then, the two-phase theory was developed based on the aggregative nature of gas-solid fluidization, represented by Toomey, Rowe and Davidson. The classification of particulate and aggregative fluidization was then proposed by Wilhelm and Kwauk. This work introduced the development of fluidization theory, and comprehensively reviewed the two-phase flow and bubbling behaviors for different types of powders, aiming to provide an overall understanding of the gas-solid fluidization. The phase transfer and reaction models were also reviewed, and the reaction conversions in different types of fluidized bed reactors were calculated, giving a hint for the prediction and simulation of reactor performance. These theoretical and experimental works are of great significance on fluidization and provide the basis for enhancing multiphase reaction processes.