Fluid-dynamic experimental study in a bubble column with internals

The main objective of this work was to determine the influence of the air v elocity, the solid load concentration and the average solid particle diamet er in the gas hold-up and solid distribution inside a bed with internals. P ilot scale equipment conformed by a column of square traverse section was u sed. In the central part of this equipment, there is a bank of 49 tubes in an aligned arrangement. The three-phase system used was compressed air, tap water and sieved sand at average solid particle diameters of 130, 510 and 2300 mum. The velocities of air were varied in the range from 1.6 to 3.3 cm /s, and the solids load concentration from 0 to 30% w/w. Results obtained a llows to conclude that when increasing the gas velocities and the solids lo ad concentration, and when diminishing the solid particle diameter, the gas hold-up increases. Additionally, quasi-symmetrical and parabolic shapes we re detected in the traversal solid concentration profiles, as well as decre asing with height in the axial direction. These profiles, axial and travers e ones, become more uniform as the air velocity increases. (C) 2001 Elsevie r Science Ltd.