Determination of local hydrodynamic parameters in bubble columns by the electrodiffusion method with oxygen as depolarizer

An electrodiffusional three-segment probe was developed with which local axial and radial liquid velocities can be determined. Application of this probe in gas-liquid flow yields information on local gas hold-up. In coalescing media the commonly used redox-system Fe(CN) ₆ ³⁻ /Fe(CN) ₆ ⁴ should be replaced by dissolved oxygen as depolarizer. Measurements of local axial and radial liquid velocity and turbulence intensity in different bubble columns (D = 150 and 600 mm) showed good agreement with data obtained by hotfilm anemometry. This paper was presented at the International Workshop on Electrodiffusion Diagnostics of Flows held in Dourdan, France, May 1993.