Few questions

Hi Rahul,

[quote]Why peizo electric quartz cystal is the preffered in ultrasound ? why not other ceramic material ?[/quote]
You need a way to convert electricity to motion. The [url=http://en.wikipedia.org/wiki/Piezoelectricity]piezoelectric effect[/url] is one of the most efficient.

[quote]Power ultrasound ( low frequency and high power ) can be made to operate 24-7 ? How do you remove heat ? Heat sink when you talk about large ultrasound ?[/quote]
Yes. You remove heat the same way as you would any other machine - conduction, convection and radiation. In practice it depends on how much heat you're trying to dissipate but forced air cooling is typical and liquid cooling can also be used if needed (with care, obviously, considering the high voltages).

[quote]What is the typical efficiceny when the power from electricity is transeffered to the desired accoustic effect. ( energy losses in temperature ) ? Does the power loss go up exponentially with the power of ultrasound going up ?[/quote]
You'd need to talk to the manufacturers but well above 90% is possible. Power losses can rise rapidly with the amplitude (not the power level necessarily). They're usually non-linear but again not necessarily exponential.

[quote]Can you change the power and the frequency of ultrasound ?[/quote]
Of course.

[quote]Delivery device of maintenance issues ?

Miscellenous maintenance issues ?[/quote]
Not too sure what you mean here. Certainly there are maintenance requirements and potential long-term issues with fatigue failure.

For more information please see my [url=http://www.powerultrasonics.com/content/introduction-power-ultrasonics]I... to Ultrasonics[/url].

HTH

Chris - PowerUltrasonics.com site owner, chief cook and bottle-washer.