Heat transfer to immersed and boundary surfaces in fluidized beds

An experimental study of heat transfer into gas-fluidized beds was performed with heat transfer into discriminated areas of the boundary walls, and into single and muptiple elements immersed in the bed, and with glass ballotini ranging from 100 μm to 1 mm dia, on Diakon (Perspex) particles of 325 μm, and on Ni particles of 275 and 325 μm. The onset of slugging in the fluidized bed had a large effect on heat transfer. The required weight of particles was poured into the bed before starting the experiment, then the air flow rate was set to the desired reading on the rotameter. The valves controlling the passage of steam to the heat exchanger were opened allowing steam to enter the required heat exchange sections. The sections of the heat exchanger were bled to remove any air present. The study of maximum heat transfer alone was likely to be only a practical guide in applications of heat transfer, and the occurrence of slugging conditions in gas-fluidized beds will cause a reduction of heat transfer.