Incorporation of nanoparticle clusters into a liquid using a proprietary design mixer, Ytron Y Jet

Abstract

This paper reports the comparative performance of a proprietary design mixer, Ytron Y Jet, on the incorporation of clusters of nanoscale silica powder into water. Two sets of characteristic power curves were obtained for Ytron Y Jet depending on whether the valve on feed tube was open or closed. Whilst there was little difference at low speeds, as the speed was increased entrainment from the feed tube decreased Po which would be as a consequence of a decrease of the pressure difference between the two sides of the rotating blades. Drawdown time values determined for surface additions followed the same trends reported for traditional impellers. Powder incorporation became faster with increasing power input at a given concentration and for incremental additions of 1% (w:w), incorporation rate decreased steeply with increasing concentration. With the use of the feed tube, which is part of the design, particles could be introduced into the impeller region, and incorporation rate could be maintained constant over a wide concentration range. This suggests that whilst the flow field in the vicinity of the impeller is not significantly modified with changes in viscosity and rheology, away from the impeller, close to liquid surface liquid velocities die out quickly. When a highly non-Newtonian rheology (Bingham plastic) developed with further particle addition, incorporation rate decreased. Ability to feed into the impeller region is the main advantage this design offers for this application.