Tomographic Imaging During Semi-Batch Reactive Precipitation of Barium Sulphate in a Stirred Vessel

The work reported in this paper has illustrated, for the first time, the capability of three-dimensional EIT to monitor reactive systems under realistic process conditions and scale. The semi-batch precipitation of barium sulphate from barium chloride and sodium sulphate has been investigated in a 200 litre stirred tank reactor. Experiments have been performed using both Rushton and pitched blade turbines under a range of agitation rates with a surface feed of barium chloride. The repeatability of EIT in monitoring the reaction progress has been illustrated. The visualisation of plume structure and evolution during the semi-batch reaction has been examined in 3D. The quantification of the effect of changes in reactor level on reconstructed images has also been examined suggesting this is a limitation to the commonly used finite element approach, as only a 2 % change can cause significant effects.