Apparatus for suspension of articles in an ultrasonic field

Abstract

The present invention is a system for the comminution of passivating layers on particles to facilitate particle digestion. A vessel comprises a lower portion and an upper portion. The lower portion has an inner surface with an increasing cross sectional area in the upward direction. The upper portion is in fluid communication with the lower portion. The upper portion has an inner surface with a substantially constant cross sectional area. A focused ultrasonic source is positioned so as to sonicate material in the lower portion. At least one fluid inlet is so arranged and constructed relative to the lower portion to introduce fluid into a lower section of the lower portion in a manner so as to cause helical, upward circulation of any particles in the lower portion. A flow re-direction mechanism is positioned in the upper portion so as to stop the helical, upward circulation of the particles and to convert the circulation to an upward, substantially non-circular flow. Thus, the velocity of the particles is reduced, allowing the particles either to fall back down to the lower portion, or to continue upward in the upper portion in accordance with their size. At least one outlet is arranged and constructed relative to the lower portion for providing an exit of the fluid and particles less than a desired threshold size. A particle outlet is provided for adding particles to the vessel.