A Reflection of Gas-Solid Fluidization Regimes

Flow patterns and flow regimes in gas-solid fluidization systems have attracted a great attention in the fluidization research community since 1940s. A number of flow regime maps have been proposed to distinguish different unique flow patterns, such as bubbling, slugging, turbulent and fast fluidization, and dilute phase transport, but controversies still exist on turbulent fluidization, which was first proposed in late 1960s, fast fluidization, which was first proposed in late 1970s, and high density suspension upflow, which was proposed in late 1990s. We will present the recent advances in understanding the transition among turbulent fluidization, fast fluidization and dense suspension upflow regimes. The future research needs in developing a generalized flow regime diagram are proposed based on improved understanding of high velocity fluidization and dense suspension flow in the presence of equipment configuration and operational constraints.