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I'm building an ultrasound cleaner. The main chamber is filled with water and it is heated. The chamber is completely sealed so the pressure inside increases with the temperature. An ultrasound emitter will be added to the bottom to increase cleaning effectiveness. Do I have to worry about the temperature/pressure increasing considerably inside the chamber because of the added ultrasound energy? Are the cavitation bubble's effects localized do the bubble itself or should I expect a considerable increase in pressure/temperature inside the chamber?

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If the vessel can go above 15psi, you will need a pressure relief device. This is the case for any pressure vessel irrespective of the ultrasonic consideration. A standard water heater pop off will probably work fine provided your vessel is rated for that pressure.

Most ultrasonic cleaners run at atmospheric pressure. There is no real reason to run at higher pressure unless you are using a solution other than water and don't want it to evaporate.

Heat addition can be calculated from power input. For example if the unit is 12vdc at 2amps it will add 24watts of heat to the system. Your ultrasonic piezo element will have a maximum design temperature. You will need to keep below this temperature by either cooling the piezo element or the whole vessel.

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  • $\begingroup$ I don't understand how your answer answers the question. Are you saying that there will be an increase in temperature that will be equivalent to the power input of the ultrasound emitter? $\endgroup$ – gummibear Jul 31 '17 at 17:46
  • $\begingroup$ Correct, 100% of the energy input will eventually become heat. $\endgroup$ – ericnutsch Jul 31 '17 at 19:00
  • $\begingroup$ @gummibear: ...plus there's no good reason to keep the chamber completely sealed. There are special cleaning solutions, but they don't require sealing, and with normal use, will need to be replaced (saturated with whatever waste product you wash off the items cleaned) long before it drying up becomes an issue. It also contains a temperature regulator; cooling is handled through standard conduction/convection through walls to ambient air, so it only has a heater to keep the temperature optimal. $\endgroup$ – SF. Aug 28 '17 at 11:52

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