Fluid′s Flowing Characteristics in Forced Inner Recycling Reactor

This paper investigates the distributions of coal concentration, coal slurry and fluctuation of bed′s pressure based on "coal-water-air" system in a nonreaction status in order to explore the flow characteristics of coal slurry in the forced inner recycling reactor used in coal direct liquefaction technology. With the following experimental condition: air′s superficial velocity of 3.9-5.3 cm/s and coal slurry′s superficial velocity of 4.5-12.5 cm/s in a cold model reactor with diameter of 200 mm, the results indicate that the coal concentration is narrowly distributed inside the reactor and equals to that of the feedstock without sedimentation of coal particles. The forced inner recycling reactor is better than bubbling reactor because it can alleviate or avoid the deposition of solid particles with high density due to the uniform distribution of velocity. The internals influence the flow status with intensive turbulence and backmixing between distribution plate and recycle cup.