The History Of Ultrasound: The Cavitation

People have come up with many ways to clean the surfaces of various contaminants. Now the list is replenished with ultrasound. Ultrasonic cleaning either replaces or complements traditional treatment methods and techniques – from manual operations with different solutions to jet washing machines.

One of the main advantages of ultrasonic cleaning over other methods is its unsurpassed level of efficiency, furthermore it is much easier to clean parts with a complicated shape, difficult places, narrow slit, small holes and cavities. Ultrasonic cleaning efficiency allows replacement of flammable or expensive organic solvents with aqueous solutions of alkali metal salts, liquid freon and other less dangerous and less expensive substances. The industrial application is gaining momentum with the emergence of innovating businesses like Hilsonic – one of the most advanced ultrasonic cleaner manufacturers in UK.

Cavitation story

How do you explain the high efficiency of ultrasonic cleaning? The answer to this question is connected with a very interesting physical phenomenon called cavitation (from Latin ‘cavitas’ means ‘empty’).

In theory, the existence of the phenomenon is known since then as the Petersburg academician Leonhard Euler proved the possibility of breaks formation in the fluid (voids) due to local pressure reduction followed by slamming any cavities. But in fact Euler predicted cavitation and never saw it in action.

Cavitation was encountered massively much later during the 20th century, when side paddle wheels were removed from the ships in favor of the screws rotating at high speed. Captains began to notice that the speed of their vessels with the passage of time gradually falls for no apparent reason. But the reason was there, and it was quite visible. When examining screws one of the ships set out in the dock for repairs, its blades looked like slightly damaged across their surface. This phenomenon, of course, was immediately studied, as shipbuilders and hydraulic turbines manufacturers were puzzled about the ways to deal with this formidable and implacable enemy, how to protect the propeller blades and turbines from the damaging effects of clouds of cavitation bubbles, which have been found. (more…)