Abstract: Various embodiments of the present disclosure are directed to a device and a method for producing a standing ultrasonic field having the frequency f in a liquid. In one example embodiment, the device includes at least one oscillation element, a substantially dimensionally stable vessel having an outside wall and a substantially circular-cylindrical interior, the vessel receiving the liquid and the at least one oscillation element. The at least one oscillation element acoustically connected to the outside wall of the vessel and electrically excited at the frequency f. The substantially circular-cylindrical interior receives liquid with an inner radius ro at least in the region of the oscillation element. The oscillation element has a mean thickness p and a width b in the direction orthogonal to a main axis of the interior, and the width b is not greater than the inner diameter 2ro.

Abstract: Energy-efficient separation of particulates from fluids is based on determining particulate mass removal as a function of applied energy. Energy-efficient ultrasonic field powers and exposure durations are applied to a particulate containing fluid, and particles removed. In some cases, ultrasonic exposures are selected that provide the maximum particulate removal per applied energy.

Abstract: A method of washing particles in an acoustic chamber includes (a) flowing a suspension of particles in a suspension medium through a standing wave generated in a standing wave volume of the acoustic chamber to accumulate within the acoustic chamber at least some of the particles as raw particle concentrate; and (b) flowing a wash medium through the acoustic chamber to wash within the acoustic chamber at least some of the particles of the raw particle concentrate, and retaining within the acoustic chamber at least some washed particles.

Abstract: A method of washing particles in an acoustic chamber includes (a) flowing a suspension of particles in a suspension medium through a standing wave generated in a standing wave volume of the acoustic chamber to accumulate within the acoustic chamber at least some of the particles as raw particle concentrate; and (b) flowing a wash medium through the acoustic chamber to wash within the acoustic chamber at least some of the particles of the raw particle concentrate, and retaining within the acoustic chamber at least some washed particles.

Abstract: The invention relates to an apparatus for separating dispersed particles or similar particles (4), comprising a separating vessel (1) which is provided with at least one transducer (2) for generating ultrasonic waves in the form of a wave with substantially perpendicularly extending oscillation node surfaces, an inlet opening (3) for the dispersion, an outlet opening (6) for the liquid medium and a discharge opening (5) for the separated particles. An effective separation can be achieved in such a way that the separating vessel (1) contains a separating surface (7, 8, 9) which is inclined at an acute angle (?) relative to the horizontal in the used position.

Abstract: Particulate material suspended in a fluid is separated and recycled by means of an ultrasonic resonance wave. In a preferred embodiment, the ultrasonic resonance field is generated within a multilayered composite resonator system including a transducer, the suspension and a mirror parallel to each other. Dimensions and frequencies resonant to the whole system but not exciting Eigen-frequencies of transducer and mirror itself are chosen so that thermal dissipation is minimized. Generally, the process is suitable for all kinds of particles (solid, liquid or gaseous disperse phases) especially for hydrosols (particles in water) and for separation of biological particles such as mammalian, bacterial and plant cells or aggregates. Specialized applications in biotechnology are described including an acoustic filter for mammalian cell bioreactors or the selective retention of viable cells relative to nonviable cells.

Abstract: Particulate material suspended in a fluid is separated and recycled by means of an ultrasonic resonance wave. In a preferred embodiment, the ultrasonic resonance field is generated within a multilayered composite resonator system including a transducer, the suspension and a mirror parallel to each other. Dimensions and frequencies resonant to the whole system but not exciting Eigen-frequencies of transducer and mirror itself are chosen so that thermal dissipation is minimized. Criteria for flow direction and flow rate are defined in order to maintain a high-quality factor of the composite resonator and to achieve a high-separation efficiency. Generally, the process is suitable for all kinds of particles (solid, liquid or gaseous disperse phases) especially for hydrosols (particles in water) and for separation of biological particles such as mammalian, bacterial and plant cells or aggregates.

Abstract: Particulate material suspended in a fluid is separated and recycled by means of an ultrasonic resonance wave. In a preferred embodiment, the ultrasonic resonance field is generated within a multilayered composite resonator system including a transducer, the suspension and a mirror parallel to each other. Dimensions and frequencies resonant to the whole system but not exciting Eigen-frequencies of transducer and mirror itself are chosen so that thermal dissipation is minimized. Generally, the process is suitable for all kinds of particles (solid, liquid or gaseous disperse phases) especially for hydrosols (particles in water) and for separation of biological particles such as mammalian, bacterial and plant cells or aggregates. Specialized applications in biotechnology are described including an acoustic filter for mammalian cell bioreactors or the selective retention of viable cells relative to non-viable cells.