An Experimental Assessment of Using Different Sizes of Immersed Heating Surfaces on Heat Transfer Coefficient in Gas-Solid Fluidized Bed Reactor

This research is mainly concerned on studying the effects of heating surface area of immersing heater and particles size of bed packing on values of heat transfer coefficient (HTCs) under different air flow rates. Experiments were conducted in a gas-solid fluidized bed to study the steady-state heat transfer between gas and solid, along with the surface of the bed at various velocities, ranging from static bed to fluidized bed conditions (0.024-0.387 m/s). The bed column was 172 mm in diameter and 1000 mm in height, attached with a horizontal heating tube of different diameters (19.5, 25.4, and 30 mm). Three different sizes of sand particle were employed (i.e. 200, 300 and 400 mu m). HTCs are shown to rise with fluidizing air velocity while exhibiting a reverse association with particle size. The influence of heating tube diameter on HTC has been examined with remarkable fluctuations revealing the bed's hydrodynamic characteristics.