Abstract: Systems and methods for achieving cavitation at high static pressures which may be used in acoustic applications and research such as in liquid metal resonators. Novel preparation and electroplating methods are disclosed to improve boundary layer conditions. A chemical cleaning loop for containment and treatment for oxide removal and to develop a dynamic system for chemically treating liquid metal disposed in a liquid metal loop is also described. A liquid metal handling loop for containment and treatment is provided to maintain cleanliness of bulk liquid metal.

Abstract: A system including an ultrasonic resonance chamber containing a cavitation reaction chamber therein is described. In some embodiments, the resonance chamber or resonator comprises a spherical metal shell having fluid and other couplings and containing a first liquid that carries an acoustic field within the resonator. A second fluid or material that can flow within the reaction chamber or reactor is disposed at a location in the resonator so that the two fluids do not mix but the acoustic field in the resonator can generate cavitation inside the reactor to cause a desired transformation or reaction in the second fluid or material.

Abstract: Systems and methods for achieving cavitation at high static pressures which may be used in acoustic applications and research such as in liquid metal resonators. Novel preparation and electroplating methods are disclosed to improve boundary layer conditions. A chemical cleaning loop for containment and treatment for oxide removal and to develop a dynamic system for chemically treating liquid metal disposed in a liquid metal loop is also described. A liquid metal handling loop for containment and treatment is provided to maintain cleanliness of bulk liquid metal.

Abstract: A system and method for treating biomass so as to convert the biomass into a useful form is provided. In some embodiments, the system and method allow treating a biomass mixed in a fluid medium in an acoustic resonator chamber. The chamber may be used to mix the biomass with other chemical agents or catalysts. The chamber is also coupled to one or more acoustical drivers to provide an acoustical (e.g., ultrasonic) field in the chamber, which can also be driven to cause acoustic cavitation in some embodiments. The acoustic resonator chamber may also be placed under static pressure to enhance a mechanical, acoustical, or chemical effect during processing. Various examples of co-processing or pre-processing stages are also provided, including acid, base, AFEX, ammonia and other stages to enhance a desired effect.

Abstract: A cavitation system in which a source gas, e.g., a reactant, is loaded into the cavitation medium prior to cavitation is provided. The cavitation system includes a cavitation chamber with suitable cavitation drivers and a cavitation medium reservoir, the chamber and reservoir being flexibly coupled together via a pair of conduits. The conduits can be fabricated from a plastic or, as is preferred for higher temperature liquids, a metal. Typically metal conduits are formed into a coil, thus providing the desired flexibility. Flexibility is required in order to allow the relative positions of the cavitation chamber and the cavitation medium reservoir to be varied.

Abstract: A system and method for degassing a cavitation fluid is provided. The cavitation system of the invention includes a cavitation chamber with one or more cavitation drivers and a degassing system coupled to the chamber. One or more heaters, such as resistive heaters, are coupled to an external surface of the cavitation chamber such that heat from the heaters is transmitted through the wall of the cavitation chamber and into localized regions of the cavitation fluid contained within the cavitation chamber. The heater or heaters increase the temperature of the localized regions of the cavitation fluid to a temperature above the boiling temperature of the cavitation fluid, thereby creating vapor bubbles which capture gas trapped within the cavitation fluid through a rectified diffusion process. A cavitation fluid cooler can be used to insure that the average temperature of the cavitation fluid is below that of the boiling temperature.

Abstract: Systems and methods for treating small elongated fibrous and particles of certain materials, e.g., PTFE materials in a suspension are presented. In some instances, high-intensity ultrasound (or acoustical energy) is applied to a sample of the material, through a fluid coupling medium or suspension, to achieve a material transformation in the sample. In various embodiments, fibrillation of particles of PTFE or similar materials is accomplished, or the formation of extended structures of these materials is caused or enhanced. Also, the ability to separate long fiber samples by ultrasonic or acoustic cavitation action is provided.

Abstract: Methods and systems for electrodeposition of Indium, Gallium, or other metals within a metal acoustic resonator chamber are provided, including for electrodeposition of Indium or Gallium as a strike layer on an interior surface of a cavitation chamber. The resultant strike layer affords an accommodating wetting surface for subsequent filling with a liquid metal and performing cavitation therein. In some embodiments, this allows for the use of liquid metal in an acoustic resonator without the damping effects inherent with oxide boundaries or other defects.

Abstract: An apparatus for cavitation and sonoluminescence is provided. In some embodiments the apparatus provides high-intensity shock waves that modify the properties of the liquid medium in the resonator and thereby alter the optical and electrical properties of the liquid. Methods for studying the acoustical and optical characteristics of the liquid and the sound fields in such scenarios are enabled and thereby testing and analysis of the same are made possible.

Abstract: A system for achieving bubble stability within a cavitation chamber is provided. The system includes an impeller assembly, the impeller assembly having at least one impeller located within the cavitation chamber. A motor, coupled to the impeller by a drive shaft, rotates the impeller thereby causing bubbles within the cavitation chamber to move toward the impeller's axis of rotation. As a consequence, the bubbles become more stable. Preferably the axis of rotation of the impeller is positioned in a substantially horizontal plane, thus allowing the rotating impeller to counteract the tendency of the bubbles to drift upward and to accumulate on the upper, inner surfaces of the cavitation chamber. The impeller can be rotated continuously throughout the cavitation process or stopped prior to cavitating the bubbles within the cavitation chamber.

Abstract: A method of fabricating a spherical cavitation. Depending upon the chamber's composition and wall thickness, chambers fabricated with the disclosed techniques can be used with either low or high pressure systems. During chamber fabrication, initially two spherical half portions are fabricated and then the two half portions are joined together to form the desired cavitation chamber. During the fabrication of each chamber half, the interior spherical surface is completed first and then the outer spherical surface. Prior to joining the two spherical cavitation chamber halves, the surfaces to be mated are finished, preferably to a surface flatness of at least 0.01 inches. Electron beam welding is used to join the chamber halves together. Preferably the electron beam welding operation is performed under vacuum conditions. During electron beam welding, the two chamber halves are aligned and held together while the electron beam forms a weld along the chamber seam.

Abstract: A method for forming and imploding cavities within a cavitation chamber is provided. A hydraulically actuated piston is withdrawn to form the desired cavities and then extended to implode the cavities. The cavitation fluid is degassed prior to hydraulically driving cavitation within the chamber. Degassing can be performed within the cavitation chamber or within a separate degassing chamber. In one aspect, a coupling sleeve is interposed between the hydraulic driver and the cavitation chamber. Preferably the coupling sleeve is evacuated.

Abstract: A cavitation system for forming and imploding cavities within a cavitation chamber is provided. The system includes a hydraulically actuated driver coupled to the cavitation chamber. A cavitation piston, coupled to a hydraulic piston, forms the desired cavities during piston retraction and then implodes the cavities during piston extension. Preferably the cavitation fluid is degassed prior to hydraulically driving cavitation within the chamber. Degassing can be performed within the cavitation chamber or within a separate degassing chamber which is preferably connected to the cavitation chamber. In one aspect, a coupling sleeve is interposed between the hydraulic driver and the cavitation chamber, the coupling sleeve housing at least a portion of the cavitation piston drive rod. Preferably the coupling sleeve can be evacuated. In another aspect, a cavitation fluid circulatory system is coupled to the cavitation chamber.

Abstract: A cavitation chamber separated into three volumes by a pair of gas-tight and liquid-tight seals, each seal formed by the combination of a rigid acoustic reflector and a flexible member, is provided. During chamber operation, only one of the three volumes contains cavitation fluid, the other two chamber volumes remaining devoid of cavitation fluid. The cavitation system also includes a cavitation fluid reservoir coupled to the cavitation chamber by a conduit, a valve allowing the cavitation chamber to be isolated from the cavitation fluid reservoir. A second conduit couples the two unfilled chamber volumes to a region above the liquid free surface within the cavitation fluid reservoir. A second valve allows the two unfilled chamber volumes to either be coupled to the cavitation fluid reservoir by the second conduit, or be coupled to a third conduit, the third conduit leading either to the ambient atmosphere or to a high pressure gas source. The cavitation system also includes at least one acoustic driver.

Abstract: A method and apparatus for monitoring a temperature difference between two regions within a cavitation system is provided. The system's cavitation chamber is partially or completely filled with cavitation fluid, the amount that the system is filled controlling whether a cavitation fluid free surface is formed within the cavitation chamber or a conduit coupled to the chamber. Regardless of whether the region of the system above the cavitation fluid free surface is within the chamber or within the conduit, a temperature difference is created between this region and the cavitation fluid within the cavitation chamber. The temperature difference between these two regions is monitored by monitoring the temperature of each region. The temperature difference can be created by either heating the region above the cavitation fluid free surface, cooling the cavitation fluid, or both.

Abstract: A cavitation system for forming and imploding cavities within a cavitation chamber is provided. The system includes a hydraulically actuated driver coupled to the cavitation chamber. A cavitation piston, coupled to a hydraulic piston, forms the desired cavities during piston retraction and then implodes the cavities during piston extension. Preferably the cavitation fluid is degassed prior to hydraulically driving cavitation within the chamber. Degassing can be performed within the cavitation chamber or within a separate degassing chamber which is preferably connected to the cavitation chamber. In one aspect, a coupling sleeve is interposed between the hydraulic driver and the cavitation chamber, the coupling sleeve housing at least a portion of the cavitation piston drive rod. Preferably the coupling sleeve can be evacuated. In another aspect, a cavitation fluid circulatory system is coupled to the cavitation chamber.

Abstract: A cavitation chamber separated into two volumes by a gas-tight and liquid-tight seal, the seal formed by the combination of a rigid acoustic reflector and a flexible member, is provided. The rigid reflector improves the cavitation characteristics of the chamber while the flexible member insures that the reflector can move during the cavitation process. One of the two chamber volumes is filled, or at least partially filled, with cavitation fluid while the other chamber volume remains devoid of cavitation fluid during system operation. A conduit couples a region above the liquid free surface in one cavitation volume to the second, unfilled chamber volume, thus preventing the reflector from being subjected to undue pressures. An acoustic driver, such as a ring of piezoelectric material, is coupled to the chamber and used to drive cavitation within the cavitation fluid contained within the chamber.

Abstract: A method of operating a cavitation system in which the cavitation chamber is separated into at least three distinct chamber volumes by, for example, first fabricating and then installing a pair of gas-tight and liquid-tight seals into the cavitation chamber, is provided. Each chamber volume seal is fabricated from a rigid reflector and a flexible member. During chamber operation, only one of the three volumes contains cavitation fluid, the other two chamber volumes remaining devoid of cavitation fluid. By controlling the pressure within the two unfilled chamber volumes, the rigid reflectors can be used as a means of increasing the static pressure within the fluid-filled chamber volume.

Abstract: A method for initiating cavitation within the fluid within a cavitation chamber is provided. In the cavitation preparatory steps, a hydraulically actuated piston is partially withdrawn and then the cavitation chamber is isolated. Once the chamber is isolated, the hydraulic piston is further withdrawn in order to form the desired cavities and then extended to implode the cavities. At least one impeller, located within the cavitation chamber, is rotated in order to stabilize the cavities.

Abstract: A method and apparatus of circulating cavitation fluid within a cavitation fluid circulatory system is provided. The system provides a means of circulating the cavitation fluid through a cavitation chamber, before or during cavitation chamber operation, as well as a means of draining and filling the chamber with minimal, if any, exposure of the cavitation fluid to the outside environment. The apparatus includes a network of conduits coupling the cavitation chamber to a cavitation fluid reservoir and at least one external fluid pump. Preferably the cavitation fluid reservoir serves the dual function of fluid reservoir and degassing chamber. Manipulation of various valves within the conduit network allows the cavitation fluid to either be pumped from the reservoir into the cavitation chamber or from the cavitation chamber into the reservoir.