Vietinghoff, Niclas vonLungrin, WaldemarSchulzke, RaphaelTilly, JonasAgar, David W.2020-12-112020-12-112020-12-04http://hdl.handle.net/2003/39867http://dx.doi.org/10.17877/DE290R-21758Applying multiphase systems in microreactors leads to an intensification of heat and mass transport. Critical aspects of the well-studied segmented slug-flow, such as bubble generation and pump control, can be automated, provided a robust sensor for the reliable determination of velocity, phase lengths, and phase ratio(s) is available. In this work, a fast and low-priced sensor is presented, based on two optical transmission sensors detecting flow characteristics noninvasively together with a microcontroller. The resulting signal is mainly due to refraction of the bubble-specific geometries as shown by a simulation of light paths. The high performance of the processing procedure, utilizing the derivative of the signal, is demonstrated for a bi- and triphasic slug flow. The error of <5% is entirely reasonable for the purpose envisaged. The sensor presented is very fast, robust, and inexpensive, thus enhancing the attractiveness of parallelized capillary reactors for industrial applications.enSegmented slug flowOptoelectric sensorOnline velocity measurementMultiphase systemsCapillary reactor660Text