Controlling the particle cut size of a dry cyclone using acetone

In this study, we investigated the interaction between particles and the wall in the presence of mist to improve the particle classification performance of a dry cyclone. The interaction between a silica particle and a mica surface in the presence of a flowing acetone mist was measured by performing atomic force microscopy (AFM), which showed that an attractive force was generated and became stronger as time passed while acetone mist was supplied to the system, probably because of static electricity. In a dry cyclone system, this attractive force could enhance the classification performance. In particular, when acetone mist was supplied into the cyclone from the upper part of the dust box at higher flow rates, the classification performance was enhanced. Because acetone is highly volatile and has a low viscosity, the classification performance was improved by the evaporated acetone even when a cyclone with a dust box filled with acetone was used instead of a nozzle supplying the mist. In this case, the ratio of the mass of the particles collected by the upper part of the cyclone to the total mass of the feed powder was increased, probably because of the attractive force between the silica particles and the wall of the cyclone. Moreover, the cut size of the dry cyclone could be controlled by changing the amount of acetone in the dust box of the cyclone.