Chemical Engineering Science, Vol.100, 15-22, 2013
Comprehensive study of regime transitions throughout a bubble column using resistivity probe
Flow regime transitions were experimentally characterized using several local bubble properties measured by a double-needle resistivity probe. Experiments were carried out in a bubble column of 0.09 m diameter and 1.8 m height. The superficial gas velocity was changed from 0.005 to 0.070 m/s and the superficial liquid velocity from 0.003 to 0.060 m/s. Average bubble chord length, bubble frequency and sauter mean bubble chord length were obtained at various locations of the column by placing the probe at three axial and six radial positions. Transitions between dispersed bubble flow, discrete bubble flow, coalesced bubble flow and slug flow were detected at these locations. A comparison between transition points at different locations verified that regime transition occurs throughout the bubble column at nearly the same superficial gas and liquid velocities. A flow regime map was also obtained based on the local measurements of the bubble properties at different locations. (C) 2013 Elsevier Ltd. All rights reserved.