Hydrodynamic study of gas-solid flow in an internally circulating fluidized bed (ICFB) using experimental and CFD techniques

Circulating fluidized bed (CFB) solid circulation systems are widely used in the process of catalyst regeneration, coal gasification, coking, thermal cracking, drying, incineration of solids waste as well as many other applications. However, conventional circulating fluidized beds require a tall tower as a solids riser and externally circulation of solids with the help of cyclones. Therefore to alleviate such problems encounter with CFB, several new generations fluidized beds have been developed. A circulating fluidized bed called as an internally circulating fluidized bed (ICFB) with a draft tube is one of the novel design. An ICFB is a type of fluidized bed with centrally located draft tube, which divides the bed into two sections called as annular section and draft tube riser. Because of simple and flexibility of operation have its own advantages. Literature review shows that there is still considerable uncertainty in establishing complete hydrodynamics of ICFB. Only few computational fluid dynamics (CFD) simulation studies were reported on ICFB and that to most of them considered 2D geometry of ICFB. Moreover, in all CFD simulations, particles were assumed to mono sized particles