1. Optical Fiber Probes for Bubble Dynamics Measurement in Bubble Columns J. L. Xue, M. H. Al-Dahhan & M. P. Dudukovic In cooperation with Robert F. Mudde Delft University of Technology, The Netherlands Chemical Reaction Engineering Laboratory (CREL) November, 2001 CHEMICAL REACTION ENGINEERING LABORATORY

2. Configuration of the four  point fiber optical probe Sketch of pulse sequencesBubble rise velocity: Bubble chordal length pierced by probe tip: Local gas holdup: L r Probe Tip0 Tip3 Tip1 Tip2 Three of the tips are of the same length and form an equilateral triangle. The central tip is about 1.5mm longer than the others. The diameter of the probe is 1.2mm (r=0.6mm) The Configuration of the Four-point Probe: Tip1 Tip3 Tip2     Tip0 rr r

3. CHEMICAL REACTION ENGINEERING LABORATORY Calculated Relative Error for Bubble Velocity due to the Deviation of the Bubble Velocity from the Probe Axial Direction (L=1.5mm, r=0.6mm)  (degree)  (degree) Measurement Error due to Bubble Fluctuation and the Deviation of the Bubble velocity from the Probe Axial Direction: v T3T3 T1T1 T2T2 T0T0  Schematic of the Bubble Fluctuation Schematic of the Deviation of the Bubble Velocity from the Probe Axial Direction

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