Investigation of Cavitation in NaCl Solutions in a Sonochemical Reactor Using the Foil Test Method

Ultrasonic baths and sonochemical reactors are widely used in industrial applications dealing with surface cleaning and chemical synthesis.The processes of erosion, cleaning and structuring of the surface can be typically controlled by changing relevant influential parameters.In particular, in this work, we experimentally investigate the effect of NaCl concentration (0-5.5 mol/L) on the erosion of an aluminum foil under ultrasonic exposure at a frequency of 28 kHz.Special attention is paid to the determination of cavitation zones and their visualization using heat maps.It is found that at low NaCl concentration (0.3 mol/L), the foil destruction rate is higher than in distilled water.At higher concentrations of salt, cavitation takes place mainly in the upper part of the container.