S. Takashima et al., MEAN HEAT-TRANSFER COEFFICIENT AROUND A H ORIZONTAL SINGLE PIPE IN A FAST CIRCULATING FLUIDIZED-BED, Kagaku kogaku ronbunshu, 23(3), 1997, pp. 437-439
Mean heat transfer coefficient h(s) around a single, horizontal pipe s
ettled in a fast circulating fluidized bed was measured under various
fluidizing condition. The heat transfer coefficient could be correlate
d well with the solid fraction in gas-solid mixture flow, being a func
tion of solid circulating rate, gas velocity and riser position. The v
alue of h(s) increased as the solid circulating rate became high. Howe
ver, it was found that there was a critical solid fraction, ranged fro
m 0.01 to 0.02, over which the increasing ratio dropped to a smaller o
ne. This phenomenon was considered to be due to a characteristic chang
e of the particle behavior around pipe.