Macrosonics in industry: 4. Chemical processing

Acoustic irradiation can result in increased inter-phase mass and heat transfer rates. The second-order acoustic effects of cavitation, interfacial instability, radiation pressure and acoustic streaming are responsible for the enhancement in these rate processes. The application of sonic and ultrasonic energy in industrial processing is reviewed. A number of units using acoustic energy to enhance rates of conventional unit processes, for example, drying, solid-liquid extraction, etc, are described. In addition, new applications in waste water treatment and oil-water emulsion fuels are described. The development of newer, more efficient generators should lead to a greater use of acoustic energy for large-scale industrial processing.