Defoaming Using Ultrasound

DEFOAMINC USING ULTRASOUND 7.3.1 Brief History of Defoaming by Ultrasound... 

This same airborne ultrasound which can be used to destroy smokes is also capable of defoaming liquids by placing the acoustic source above the liquid surface upon which the foam is being generated. The methodology has proved so effective... 

As we have seen, defoaming of foams prepared from dilute, low-viscosity, aqueous surfactant solutions has been reported mainly with ultrasound in the frequency range of 20-25.8 kHz. The only reported exception to this concerns the extremely weak effect described by Komarov et al. [60] in the frequency range of 2-7 kHz. If we reasonably ignore the latter, then we can use the plot of the sound velocities for 0.99 < 0.999 shown in Figure 7.21 to estimate the range of wavelengths... 

For applications where chemical antifoam use is unacceptable, the text examines mechanical means of defoaming, such as the use of rotary devices and ultrasound. 

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