Investigating the Influence of Distributor Type, Particle Size and Rice Husk Percentage on Fluidized Beds through Cold Fluidization Experiments

Abstract

This work studies a fluidization system through cold experiments by using a mixture of rice husk and sand to investigate three parameters: type of bed distributor (perforated plate and plate with Tuyere-type injectors), sand granulometry (mean diameters of 324 µm and 647 µm) and rice husk mass ratio (from 1% to 10% of rice husk). The results reveal that the perforated distributor plate achieved a lower minimum fluidization velocity. However, the plate with Tuyere injectors generated better mixing, thus reducing possible stagnation points. An increase in the mean diameter of the sand raises the minimum fluidization velocity but also facilitates the formation of preferential channels. As for the rice husk mass ratio, values of over 5% cause stagnation points and preferential channels. It was also found that the relation between minimum fluidization velocity and rice husk ratio follows an exponential behavior, and an equation was developed to better describe their relation.

Keywords

• fluidized bed
• biomass
• rice husk
• minimum fluidization velocity
• mixing and segregation