Hydrodynamics of Circulating Fluidized Bed Systems

Abstract

Fluidized bed reactors are used in different industries to carry out multiphase chemical reactions. In these reactors, the fluid is passed through the reactor bed having granular solid materials. The velocity of the fluid is kept high enough to suspend these materials resulting to behave them like fluids. Such reactors are classified as bubbling bed, fast circulating bed or dual bed systems combining two beds depending upon the fluid velocities and constructions of the reactors. For combustion and gasification processes, circulating or dual fluidized bed systems are often preferred because they are more efficient having high throughput. However, the hydrodynamics of such fluidized beds, using normally low-grade feedstocks, is very complex and plays a critical role for successful operation of the plant. Lots of experimental and theoretical investigations are done in this area; however, the available information on the hydrodynamics is limited. In this chapter, the hydrodynamics of circulating fluidized bed systems has been discussed.