Vortex shape in unbaffled stirred vessels: experimental study via digital image analysis

摘要

There is a growing interest in using unbaffled stirred tanks for addressing certainudprocessing needs. In this work, digital image analysis coupled with a suitableudshadowgraphy-based technique is used to investigate the shape of the free-surfaceudvortex that forms in uncovered unbaffled stirred tanks.udThe technique is based on back-lighting the vessel and suitably averaging vortex shapeudover time. Impeller clearance from vessel bottom and tank filling level are varied toudinvestigate their influence on vortex shape. A correlation is finally proposed to fullyuddescribe vortex shape also when the vortex encompasses the impeller.