Similarity between fluidization and phase transition

Abstract

Generally, single-component multiphase systems exhibit three different structures and properties in solid, liquid, and gaseous state with temperature changes. The multiphase system consisting of solid particles and fluids in a circulating fluidized bed also experiences three structures with the increase of gas flow velocity, namely, bubbling, turbulence and rapid flow. Although the two systems are quite different in structure and nature, using the concept of mesoscience to analyze the state of the system, the transitional parameter, the driving force for the system state evolution and the underlying mechanisms, the two systems turn to be quite similar in nature. Their physical roots are alike in all important essentials, which are the inevitable result of the compromise in competition between different dominant mechanisms in the complex systems. After comparing the fluidization and the phase transition, a new proposition based on the energy minimization multi-scale (EMMS) model is suggested to sufficiently characterize the real non-equilibrium kinetics of phase transition.