Identify of flow patterns in bubbling fluidization

Abstract

Bubbling fluidization has been widely applied in process industries, such as power generation from coal, renewable energy production, gasification and pyrolysis. In this study, we attempted to predict solid flow patterns in a bubbling fluidized bed based on operational conditions, the air distributor and particle velocity. We first investigated the effect of operational conditions and the air distributor on solid/gas flow patterns, and investigate the correlations between solid/gas flow patterns with the solid mixing, solid and gas contact, and bubble behaviour within bubbling fluidized beds by using positron emission particle tracking (PEPT). A ‘Flow Pattern Parameter (FPP)’ is then proposed to identify the solid flow pattern in a bubbling fluidized bed. The ‘Flow Pattern Parameter (FPP)’ consists of particle kinetic energy, bed aspect ratio (H/D), pore size of air distributor, minimum fluidization velocity, and superficial gas velocity. The results show that solid flow patterns in the bubbling fluidized bed can be clearly classified based on the Flow Pattern Parameter. Different flow pattern corresponds to a certain range of the Flow Pattern Parameter.