Authors

Abstract

Time-averaged local heat transfer coefficient profiles were studied in a 0.45
m bubble column using air-water system. The effect of the superficial gas velocity and
axial locations (Z/D) on the heat transfer coefficient and its radial (r/R) profiles were
investigated in bubble column. Significant differences were observed between heat
transfer coefficients in the axial directions viz. in the bulk flow region (Z/D=4.8)
higher than in the distributor region (Z/D=0.28) by 14% -22% for increasing the
superficial gas velocity from 0.05-0.45 m/s. The heat transfer coefficients increase
with superficial gas velocities and the values in the center of the column were 9–13%
greater than those near the wall region .The characteristics of bulk flow region are
large variation in radial direction and little in axial direction for the values of heat
transfer coefficients.

Keywords