Experimental Study On Flow Characteristics Of Three-Phase Continuous Loop Reactor

The direct coal liquefaction technology has particularly strategic and realistic significance for the energy security of China. Multiphase loop reactors, in which the liquid is circulated mainly due to the density difference between the riser and downcomer but not driven by an expensive and complex circulation pump, present a lot of advantages for the coal direct liquefaction technology.As a first step to industrialize this focusing coal liquefaction technology, it is essential to study the multiphase transport characteristics of this new type reactor.In this paper, flow parameters, such as phase holdups and slurry circulation velocity, of a three-phase continuous loop reactor with a concentric draft tube were measured experimentally, with glass beads as solid phase, air as gas phase and tap water as liquid phase, respectively. Different operation conditions, including superficial gas velocity, superficial slurry feeding velocity, inlet solid loading, solid particle diameter, liquid surface intension and gas aeration modes, were adopted to demonstrate their effects on the local distributions of gas and solid hold ups and internal circulation slurry velocities. Furthermore, a flow model was developed for predicting the flow parameters.