Experimental Investigation of the Effect of Random Packings on Heat Transfer and Particle Segregation in Packed-Fluidized Bed

The heat transfer coefficient, pressure drop, and vertical segregation in a bubbling fluidized bed reactor containing random packings were investigated. The bed material was silica sand in the size range of 90−400 μm. Experiments were done for bed temperatures ranging from 400 to 900 °C and superficial gas velocities up to 0.411 m/s. Five different types of packings were evaluated: (i) RMSR (25 mm stainless steel thread saddle ring), (ii) Hiflow (25 mm stainless steel pall ring), (iii) RR6 (6 mm ceramic Raschig ring), (iv) RR10 (10 mm ceramic Raschig ring), and (v) ASB (12.7 mm aluminum silicate balls). The RMSR packing showed an increase in the heat transfer coefficient (up to 1243 W/m2 K), as compared to bubbling beds with no packings (up to 1124 W/m2 K). Also, beds with RMSR and Hiflow packings had a lower pressure drop and vertical segregation compared to low void factor packings such as RR6, RR10, and ASB.