HYDRODYNAMICS OF DUAL FLUIDIZED BED SYSTEMS WITH INTERNAL MIXING CHANNELS BETWEEN CIRCULATING AND BUBBLING FLUIDIZED BED REACTORS

摘要

We have examined a dual fluidized bed (DFB) system having internal mixing channels between the circulating fluidized bed (CFB) and bubbling fluidized bed (BFB) reactors. The bed material of the CFB reactor was supplied to the gasifier both by an external circulation loop, comprising a riser, cyclone, and standpipe, and an internal circulation loop that was implemented by making openings between the CFB and BFB reactors. The hydrodynamics and mixing characteristics of the system were investigated using a cold model test. Simple openings work very well for DFB systems, and internal mixing can be realized while maintaining stable external circulations.