Experimental Investigation on Heat Transfer in A Gas-Solid Fluidized Bed with A Bundle of Heat Exchanging Tubes

Abstract

A fluidized bed reactor is commonly used for highly exothermic reactions fordifferent chemical industrial processes. However, inefficient removal of thegenerated heat due to the exothermic reaction can seriously influence reactorperformance. Hence, quantifying and understanding the heat transfer phenomenain this reactor is essential to enhance the performance of the reactor and,consequently, the chemical process. To achieve a better quantification andunderstanding of the heat transfer in this reactor, an advanced heat transfertechnique has been used in this study to quantify the impact of the presence of thecooling tubes on the local heat transfer coefficient at four radial positions (r/R =+/- 0.58, +/- 0.03) at an axial height of H/D =15 cm from the distributor plate witha wide range of superficial gas velocities (0.2-0.48). It has been found that the localheat transfer coefficient in the fluidized bed reactor equipped with a bundle ofvertical tubes increases significantly as superficial gas velocity increases at thewall region, while different behavior was noticed at the center of the reactor.Moreover, the results show that the local heat transfer significantly decreases atthe reactor's core region for all studied superficial gas velocities. Furthermore, thenew tube arrangement offers a uniform local heat transfer profile for all studiedoperating conditions. The obtained new high-quality experimental data for thelocal heat transfer coefficient in a fluidized bed reactor equipped with a bundle oftubes can be used for validation CFD simulations, developing mathematicalmodels, facilitating design, scale-up, and operation of this reactor