Ultrasonic high-power systems

High-power ultrasound has been used to disrupt cells, disperse aggregates, and modify food texture and crystallization (Knorr et ah, 2004). The ultrasonic wave causes intense localized heating and this generates gas bubbles which cavitate and result in intense pressure and shear (Povey and Mason, 1998). It is the high pressure and shear which cause physical disruption of food components and materials and can change the rate of chemical reactions. Kentish et ah (2008) used a flow-through power ultrasound systems at 20-24 kHz to produce an oil-in-water emulsion with... 

The cup-hom (Fig. 7) can be considered as a probe system operated upside down, transforming it into a very high-power ultrasonic bath with the emitter surface in... 

Table 5.2 Experimental exponents a for power law dependency (232) dispersion of p5nx)genic powders with rotor-stator systems (RS), high pressure systems (HP), and ultrasonication (US) the applied power density Ey and achieved mean particle size x ean are indicated, values for a were derived from data or cited from source references Mandzy et al. (2005), Pohl et al. (2004), Pohl et al. (2005), Sauter and Schuchmann (2008), Sauter et al. (2008)...

Several attempts have also been made to destroy high-viscosity foams in the food industry (e.g. sugar and molasses), but unfortunately with these highly stabilized systems, the success rate is much lower. However, for the case of particle-stabilized foams (i.e. in the mineral industry, e.g. clays and carbonates) some degree of success has been achieved. Preliminary studies carried out by Sandor and Stein (18) clearly indicate that ultrasonic vibrations can both prevent the formation of foams and destroy foams stabilized with SDS surfactant and that those vibrators, which give the higher power consumption are more effective. It was also shown that the power consumption could be greatly enhanced when a broader tip was used. 

The submitters used Heat Systems-Ultrasonics Model W-220 (maximum output power 200W) with a standard horn. The checkers used a Sonics and Materials Inc. Vibra-Cell High Intensity Ultrasonic Processor (maximum power outlet 600W)... 

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