Process for controlling a reaction by ultrasonic standing wave

Abstract

Particulate material is supported in a fluid medium by means of an ultrasonic standing wave while a reaction is effected or controlled involving the material so supported, for example with the fluid medium or other material contained in the medium. In a preferred arrangement, the standing wave is established by opposed ultrasonic transducers producing convergent beams that compensate for attenuation of the ultrasonic energy in the fluid medium, and operating in the near field. The support provided by the standing wave is able to avoid settling of the particulate material in the medium and also agitates the material; both effects enhance the rate of chemical reaction and help to ensure that the particulate material is more uniformly exposed. The process has particular applications to biological reactions, such as fermentation, and to chromatography, as examples.

Dependencies are inferred from the claim text.