Electrochemical probe for bubble size prediction in a bubble column

Abstract

The purpose of this paper is to demonstrate that the electrochemical probe can be used as a means of measuring bubble sizes. The apparent local mass transfer coefficient on a spherical surface was measured in a bubble column with homogeneous bubbling regimes (bubbles of approximately equal size and uniformly distributed across the column). Thus, the characteristic average frequency of the fluctuations of the diffusion-limited current detected by the probe was postulated as being equal to the bubble frequency and led to a determination of an average bubble size in a homogeneous bubbling flow. This method could be added to other techniques already reported in the literature—for example, the optical probe and the resistivity probe. The use of electrochemical activity of dissolved oxygen for bubble size measurements in bioreactors is also discussed.