2. Heat transfer between a dense bed and a wall

Heat transfer between a fluidized bed and a wall immersed in the bed is the transfer mode most commonly used to transfer heat energy between the particulate bed and exchange surfaces, formed by the vertical walls of the bed or by tubes immersed within the fluidized inert media.

Heat transfer between a fluidized bed and a wall results from the combined action of three transfer processes.

• Transfer by particle convection and direct particle/wall contact, whereby the enthalpy of the divided solid in the bed is transferred to the wall.

  The heat capacity of the solid, per unit volume, is much greater than that of the gas: it is therefore a predominant mode of heat transfer in dense fluidized beds. The associated exchange coefficient is expressed as h _cp ...