Optimization of bubble column performance for nanoparticle collection
Résumé
Fibrous media embody the most effective and widely used method of separating ultrafine particles froma carrier fluid. The main problem associated with them is filter clogging, which induces an increasinglymarked pressure drop with time and thus imposes regular media cleaning or replacement. This contexthas prompted the idea of investigating bubble columns, which operate at constant pressure drop, asalternatives to fibrous filters. This study examines the influence of different operating conditions, suchas liquid height, air flow rate, bubble size and presence of granular beds on ultrafine particle collection.Experimental results show that bubble columns are characterised by high collection efficiency, whenthey feature a large liquid height and small diameter bubbling orifices, while their efficiencies remainlower than those of fibrous filters. Gas velocity does not greatly influence collection efficiency, but theinclusion of a granular bed, composed of beads, increases the bubble residence time in the column,thereby increasing the column collection efficiency.