Circulation and separation of binary solids in connected fluidized beds.

In this work, particle circulation and separation of binary solids were investigated in a novel fluidized bed system, constructed with two sections connected through a slit. One side contains a vigorously fluidized bed with an inclined distributor for biomass pyrolysis, while the other provides for a gentle fluidized bed for particle separation. Particle exchange through the slit was observed and analyzed by PIV to explain the driving force transporting particles between sections. An inclined distributor facilitated smooth transportation of particles to the gentle bed where the lower-density char was effectively removed from the denser bed materials. Particle transportation, and therefore, particle separation, depended on the gas flow rate into the lower end of the inclined distributor plate and was sensitively affected by the location of the slit. The driving forces of particle transport through a slit were, the instantaneous local pressure difference induced by babbles and also hydraulic head difference. [Display omitted] • Two-coupling fluidized bed via a slit is developed for a char-particle removal. • Particle exchange through a slit is analyzed by PIV methods to explain the mechanism. • The inclined gas distributor indicates good performance for particles exchange via a slit. • Driving forces of particle movement are induced by bubbles and the hydraulic head difference. [ABSTRACT FROM AUTHOR]