FLUID-DYNAMICS OF BUBBLE-COLUMNS AT ELEVATED-TEMPERATURE MODELING ANDINVESTIGATION WITH REFRACTIVE FIBER OPTIC SENSORS

Experiments are performed in a bubble column using refractive fiber op tic sensors and a paraffinic oil. A temperature range of 100-175 degre es C is considered for the study. A two-dimensional fluid recirculatio n model is applied and this allows the successfully representation of the experimental bubble rise velocity in the bottom section of the col umn and the confirmation that in the peripheral region of the column, there is important gas recirculation. Valuable insights concerning the turbulent kinematic viscosity, a key model parameter, are reported. O ther important effects such as the influence of temperature, gas super ficial velocity and axial position on the turbulent kinematic viscosit y are also described. (C) 1998 Elsevier Science S.A. All rights reserv ed.