TITLE:
Bubble and Heat Transfer Phenomena in Viscous Slurry Bubble Column
AUTHORS:
Hyo Sik Kim, Jin Ho Kim, Chan Gi Lee, Suk Hwan Kang, Kwang Jae Woo, Ho Jin Jung, Dong Wook Kim
KEYWORDS:
Gas Holdup, Slurry Bubble Column, Heat Transfer, Drift Flux Model
JOURNAL NAME:
Advances in Chemical Engineering and Science,
Vol.4 No.4,
October
7,
2014
ABSTRACT: Heat
transfer and bubble phenomena were investigated by adopting the drift flux
model in a viscous slurry bubble column reactor (SBCR), having a diameter of 0.0508 m(ID) and height 1.5 m. The effects of superficial gas
velocity (0.002 -0.164 m/s),
solid concentration (0 - 20 wt%) and liquid viscosity (paraffin oil; 16.9 mPa•s and squalane; 25.9 mPa•s) on the gas holdup
and heat transfer characteristics were examined. It was observed that the gas
holdup increased with increasing superficial gas velocity (UG), but
decreased with increasing solid concentration (SC) or slurry
viscosity. The degree of non-uniformity in a SBCR could be determined by the
modified drift flux model at the heterogeneous flow regime. The local heat
transfer coefficient (h) between the immersed heater and the bed decreased with
increasing liquid viscosity and SC, but it increased with increasing
UG. The modified Nusselt number including the gas holdup and local
heat transfer coefficient was well correlated in terms of dimensionless groups
such as Reynolds and Prandtl numbers.