Abstract Summary (Max 250 words)
Even though mixing of poly-disperse liquid-solid systems is occasionally studied in literature both numerically and experimentally, comprehensive understanding of this issue is still lacking. In presented work, systematic experiments were conducted on bi-disperse mixed batches using the new Selective Resistance Tomography (SRT) method (an extension of the conventional ERT) to measure volume fraction compositions over two horizontal planes in a model mixing vessel. The vessel was cylindrical (D = 0.3 m), with a flat-bottom and four evenly spaced baffles. It was filled by water and model solid particles (≥10% total mean volume fraction) and mixed by a PBT impeller (d = 0.1 m) at higher than critical impeller speed. The new SRT method enables distinction between two model particle species through successive measurements tailored to the species' differing electrical properties. This way, volume fraction distributions of individual particle species and corresponding individual homogeneity indices were found for different combinations of the species’ sizes, densities and loads. The results provide new insights into the general behaviour of poly-disperse mixed batches in engineering praxis and support development of hypotheses regarding how impeller power input is partitioned among particle species with differing physical properties.
