All the sound wave with the frequency being above 20 KHz is called The Ultrasonic.
Ultrasonic transmitted in the liquid can clean the surface dirt of something, which theory can be explained by the phenomenon “THE CAVITATION":When the ultrasonic transmitted distantly and closely in the liquid, hundreds of millions of tiny bubbles (cavitation core) will come into being in liguid.These cavitation will grow then break rapidly because of Ultrasonic transmitting in forms of being distant and closed. Strong concussion will strike down the dirt on surface of workpiece.
When the frequency is alter from 50Hz to 28KHz by the Ultrasonic power, the signal will be transported to the ultrasonic transducers which are felted on the underside of cleaning trough, the transducers will change high- frequency power energy to machine quiver transporting in the liquid, then, produce the phenomenon “THE CAVITATION’, so achieves cleaning aim. Because the Ultrasonic frequency is very high, reach to 28KHz, it can clean out and out the dirt of the workpiece in liquid . even, such as the workpiece which shape is involute. Only reach to liquor, workpiece would be cleanlily. Because every tiny bubbles bulk is vert small ,the great fracted energy can not produce machine destroy and can not conduce liquor temperature rise distinctly.