Developing a measurement system of fluid velocities in rotating bed reactors

Abstract: SpinChem AB's rotating bed reactor (RBR) is a small cylindrical centrifuge that allowsfor eective convective reactions between chemical substances. The aim of my master'sdissertation was to develop a measurement system that could estimate the uid velocity insidethe RBR. This report covers a quick pre-study of dierent uid measurement methods,details how we designed and constructed the system using integrated circuits and other electroniccomponents, and illustrates calibration results and nal velocity measurements. Thesystem design was based on the architecture of hot-wire constant temperature anemometry(CTA), a technique that measures the uid velocity over a heated metal wire. The resultsof this project is the measurement system itself, and the calibration and velocity measurementsgathered from experimentation. Two issues we encountered was that the calibrationprocess resulted in an overestimation of the velocity in the order of 4000 cm/s, and thatthe response to changes in velocity rates was quite slow. However, a slight tuning of thetwo calibration constants A0 & B0 smoothed the velocity estimation out to 40 cm/s, whichis more what we would expect. This illustrated how sensitive the results were to errors inthe calibration. Further investigation of the slow response, and a more stringently executedcalibration setup, could make the CTA a potential candidate for estimating the uid velocityinside the RBR.