Bed-to-immersed tube heat transfer in a circulating fluidized bed

Heat transfer characteristics between bed and the immersed tube has investigated in a circulating fluidized bed. The test facility has the dimension of 2.5 m height and 5.0 cm diameter. The operating ranges of experiment covered the superficial gas velocity of 2.0-6.0 m/sec., solid circulation rate of 20-100 kg/m(2) s. Four different sizes of sand particles were employed as the bed material. The effects of operating variables on the heat transfer coefficient were examined. The experimentally determined heat transfer coefficient was correlated in terms of effective suspension density and the qualitative analysis of heat transfer coefficient was made in conjunction with the hydrodynamic characteristics.