Experimental evaluation of the convection heat transfer coefficient of large particles moving freely in a fluidized bed reactor

摘要: Abstract Heat transfer is a key aspect in the performance of fluidized bed reactors. In particular, dense phase heat coefficient, which determines exchanged between and fuel particles, special relevance. This work presents study on that occur when introducing pelletized particles dry ice bed. The convection coefficient experimentally evaluated by means sublimation using novel methodology, consists measurement system based macro-TGA corresponding evaluation acquired data. capable measuring real time mass bed, direct measure loss particles. such measurements allows to determine Fixed regimes, varying excess gas velocity from -0.03 m/s up 0.35 m/s, were tested for two different materials, namely Ballotini glass beads alumina. results coefficients are good agreement with values reported literature, confirming reliability experimental postprocessing methodologies. general, higher velocities enhance mixing limit do not further increase. Additionally, influence buoyancy behaviour discussed. decreases substantially if present flotsam sufficiently high ensure proper circulation whole