Fluid-dynamic experimental study in a slurry bubble column with a tube bank in cross flow

• Published in: Chemical engineering communications Vol. 190; no. 1; pp. 94 - 115
• Main Authors: Goncalves, Juan José, Castro, Fidel, Teixeira, José Alberto, González-Mendizabal, Dosinda
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01-01-2003
• DOI: 10.1080/00986440302090
• EISSN: 1563-5201
• ISSN: 0098-6445

In this work, the fluid-dynamic of a slurry bubble column provided with a tube bank operating in cross flow was studied. The main objective was to determine the influence of the air velocity, the slurry velocity, and the solid concentration in the gas holdup and solid distribution inside a bed with internals. Pilot scale equipment with a column of square traverse section (0.144 m 2 ) of stainless steel with 2.20 m height was used. The column base has a truncated pyramidal shape with an inclination angle to the vertical of 20°. In the central part of the equipment, there is a bank of 49 tubes ( D =2.54 cm and L =38 cm) in an aligned arrangement ( S_L=S_T=4.4\,\rm cm ). The three-phase system used was compressed air, tap water, and sieved sand ( D_p=0.0505\,\rm cm ). The velocities of liquid and gas phases were varied in the range from 0.31 to 1.24 cm/s and from 1.41 to 3.15 cm/s, respectively, and the solids load concentration from 0 to 30% w/w. According to the results, when the liquid and gas phase velocities increase, the gas holdup, \varepsilon_G , increases, while when the solids load concentration increases, \varepsilon_G presents a local maximum at intermediate values, \varepsilon_G being the largest for the two-phase system. Analogously, the axial profiles of solids concentration showed a local maximum in the central region of the column, exactly in the area of the tube bank. In the traverse direction, the solids concentration increases gradually heading to the center of the column. These profiles, axial and traverse, become more uniform as the air velocity increases and the slurry as well. In addition, according to expectations, the solids concentration increases in each point of the column as the load concentration is increased in the system.