2009 Volume 95 Issue 12 Pages 895-901
When air is injected vertically upwards into a water-filled cylindrical vessel through a J-shaped lance, two types of swirl motions of the water in the vessel appear under specific conditions: shallow-water wave type and deep-water wave type. The swirl motions are similar to the rotary slashing. The deep-water wave type of swirl motion has high mixing ability. Small solid particles placed on the bottom of the cylindrical vessel can be lifted up into the bath through an effect of the swirl motion. The lifting behaviors of the particles can be classified into two types depending on the aspect ratio of the bath.