A multitude of useful physical and chemical processes promoted by ultrasonic cavitation have been described in laboratory studies. Industrial-scale implementation of high-intensity ultrasound has, however, been hindered by several technological limitations, making it difficult to directly scale up ultrasonic systems in order to transfer the results of the laboratory studies to the plant floor. High-capacity flow-through ultrasonic reactor systems required for commercial-scale processing of liquids can only be properly designed if all energy parameters of the cavitation region are correctly evaluated. Conditions which must be fulfilled to ensure effective and continuous operation of an ultrasonic reactor system are provided in this book, followed by a detailed description of "shockwave model of acoustic cavitation", which shows how ultrasonic energy is absorbed in the cavitation region, owing to the formation of a spherical micro-shock wave inside each vapor-gas bubble, and makes it possible to explain some newly discovered properties of acoustic cavitation that occur at extremely high intensities of ultrasound. After the theoretical background is laid out, fundamental practical aspects of industrial-scale ultrasonic equipment design are provided, specifically focusing on:
• electromechanical transducer selection principles;
• operation principles and calculation methodology of high-amplitude acoustic horns used for the generation of high-intensity acoustic cavitation in liquids;
• detailed theory of matching acoustic impedances of transducers and cavitating liquids in order to maximize the ultrasonic power transfer efficiency;
• calculation methodology of “barbell horns”, which provide the impedance matching and can help achieving the transference of all available acoustic energy from transducers into liquids. These horns are key to industrial implementation of high-power ultrasound because they permit producing extremely high ultrasonic amplitudes, while the output horn diameters and the resulting liquid processing capacity remain very large;
• optimization of the reactor chamber geometry.