Patent ID: 6065949
Filing Date: 2000-05-23
Classification: B01F,B29C,C03B

Abstract:
A system for positioning voids within a solidifying, liquid medium, said system comprising:a chamber having a plurality of sides defining an internal region and a cooling device joined to at least one of said plurality of sides, for cooling said solidifying liquid material and causing solidification of said solidifying liquid material, said chamber being a conduit having at least four walls for receiving said medium;at least one source of bubbles disposed proximate one of said plurality of sides, for introducing a plurality of bubbles into said chamber, said bubble source being positioned in a lowest wall of said chamber for allowing bubbles to flow upward through said acoustic region;at least first and second acoustic wave transmitting devices disposed proximate first and second sides of said plurality of sides of said chamber, for transmitting at least first and second acoustic energy waves at respective first and second frequencies; andwherein said first and second acoustic energy waves interact and cooperate to produce a standing wave field in an acoustically active region within said chamber, said standing wave field manipulating at least a portion of said plurality of bubbles into a matrix of bubbles having a predetermined spacing.