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roamingnome
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DIY ultrasonic cavitator
Admit it, you wouldnt mind having one.... a good one... 500W output....
I wish i grabed the one i saw once at labx...but alas...
Method for the ultrasonic treatment of a dilute alcoholic solution, www.freepatentsonline.com/4599459.html
EXAMPLE 2
Using the apparatus shown in FIG. 1, 200 liters of a fermentation mother liquor of 15% theriac to which yeast fungii was added was placed in the
fermenter 10 and fermented for 6 hours. Thereafter, the circulation pump 21 was operated to introduce the mother liquor into the ultrasonic processor
16. By the fermentation, the gas phase in the container 17 was a carbon dioxide atmosphere but in order to ensure safety and prevent oxidation of
vaporized alcohol, a small amount of carbon dioxide was added. Initially, the vacuum pump 37 was operated so that the pressure of the vacuum tank 36
was reduced. Simultaneously with the operation of the ultrasonic processor 16, the container 17 was reduced in pressure. Ultrasonic vibrations of 20
KHz with an input power of 500 W (maximum output of about 200 W) were used. Under these conditions, the ultrasonic processor 16 started to be operated
and cavitation was thus produced, followed by stationary operation. For initial one hour, 8 liters of 85% ethyl alcohol was obtained and a continuous
operation of 10 hours resulted in 40 liters of ethyl alcohol.
Pricing these things out makes  this called for
As I find relavant parts or plans for parts, ill hope to post them
but if anyone has taken this journey into building a ultrasonic superducer for cheaper then 1000 bucks please share your tips or basic understanding
of the theory....thanks
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roamingnome
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surely someone has a vibrator...
after some quick research into the topic, if your not a full blown E.E. in the mood for a relaxing side project then no one is going to build one of
these things....
super fast primer: you need three pieces of equipment
1 power supply
2 converter/transducer
3 various horn/probe attachments
the power supply is the cheapest of the bunch
the converter( Piezoelectric stack actuators) piece is like a top secret WE have the manufacturing process and your going to pay $2000 dollars for it
type of deal.
the horn could be mimiced with a lathe from titanium, but its probably worth spending $300 on it
so i stepped out and got an classic 70's power supply, its like the tube amps of the guitar world ( at least this is what i tell myself)
after that joy settled, i said lets buy a converter, well its out of date sonny boy its a babe Ruth rookie card 1600 bucks!
so the closest DIY is going to get on this thread is the realization that im just going to mix and match trying to keep all equipment for the 20 kHz
range.
so the simple 2 prong connection on the power supply is going to have to be jiffy rigged to a freaking 10 prong VWR probe
im like whats with all these freaking prongs, its + and - people
in conclusion if you reach out to buy one of these gadgets your best bet is to buy complete packages which most are, but if you
what the goods for under say 500 bucks total then i hope its just a simple matter of adapters.
fender gibson just plug it in type of thing
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Eclectic
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Google "langevin bolted ultrasonic"
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BeanyBoy
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| Quote: | Originally posted by Eclectic
Google "langevin bolted ultrasonic" |
Ooo, at:
http://ctdco.manufacturer.globalsources.com/si/6008800568969...
Look, "Request Sample".... time to break out the linen stationery...
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jpsmith123
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Here's one on ebay:
http://cgi.ebay.com/BOLT-CLAMPED-LANGEVIN-ULTRASONIC-TRANSDU...
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Twospoons
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Last time I played with something along these lines I used the transducer from a boat sonar. Running at 200kHz I produced lovely cavitation in a
small yoghurt pot glued to the top. It was 15 years ago, so I can't remember many details - except the power stage was a class B amp driving a
ferrite transformer, tuned into resonance with the piezo transducer. Crude, but it worked. Buggered if I can remember the power level, but it wasn't
huge.
maybe these guys could supply what you want:
http://www.transducer-sensor.com/ultrasonic_transducers.html...
[Edited on 9-5-2007 by Twospoons]
Helicopter: "helico" -> spiral, "pter" -> with wings
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Eclectic
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The guys selling the Lagevin units on Ebay have one for 20khz, 1000 W, but the company seems to be run by Sargent Schultz.
I Know Nothing...
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roamingnome
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thats simply too funny
i think weve all dealt with that type
so asking about the proper driving voltage is out of the question?
can you simply screw a rod or horn into the bolt instead?
whats worse however is the over clerical secretary that fundementaly assumes "new customer" means you are osama binladen
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Eclectic
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I can't even get info on which of the bare ring ceramics can be used in bolted transducers and what the power ratings are. 
There is some good info to be had Googleing "langevin bolted ultrasonic design".
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Shingoshi
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Would it be considered hijacking to reopen this old thread, for a specific task?
I want to know how to build an ultrasonic transducer strong enough to cause vigorous boiling of a liquid-coolant (for my computer project), to provide
the evaporation and subsequent drop in temperature that I desire. I think that about sums up my purpose well enough. If anyone reads this and wants to
participate, I'd appreciate it.
Shingoshi
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12AX7
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They call those, fans???
Ultrasonics don't evaporate water, they aerosolize it. I suppose the liquid temperature may actually change, depending on such factors as acoustic
dissipation, reduced air temperature (since humidity is rising), surface tension energy and possibly more. And if you're producing enough power to
boil water, wouldn't that be a direct result of the power you're adding?
What do you need water cooling on a computer for, really? Get a better processor, it's cheaper than torturing some old beast. Or wait six months for
latest technology that offers more than the 15% improvement overclocking produces. If you insist, use vacuum to lower the boiling point, or better
yet, use a proper refrigerant like freon.
Tim
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Shingoshi
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A foundation for further discussion...
I found this on another site after doing a search for "ultrasonic refrigeration". This is the direction I'm pursuing here.
| Quote: | An Oscillator (sometimes referred to as "piezo-electric transducer) emersed in water, converts a high frequency electronic signal into a high
frequency mechanical oscillation. The water tries to follow the high frequency mechancial oscillation but cannot due to its mass inertia, and a
momentary vacuum and strong compression are produced in the water.
In the negative oscillation of the transducer, the momentary vacuum causes the water to cavitate into vapor at low temperature and pressure. In the
positive oscillation of the transducer, high pressure compression waves are produced and by focusing the pressure waves on the surface of the water,
very small particles of water (average one micron in diameter) generate a mist which is quickly absorbed into the air.
Because the water vapor is produced by the ultrasonic wave and does not go through a phase change into steam or high temperature water vapor, the
Fresh Point Ultrasonic humidifiers operate on less that 7% of the demand of an electric steam canister humidifier of similar capacity and rating. The
low electrical demand and minimal maintenance reduces the cost of humidifying to levels far below those of conventional methods of generating
moisture. |
Anyone having anything of real value to add to this, please post...
A list of hints (for Google):
1.) "thermoacoustics"
http://www.lanl.gov/projects/thermoacoustics/ehistory.pdf
| Quote: | Applying Rott’s mathematics to a situation where the temperature gradient along the
channel was too weak to satisfy Rayleigh’s criterion, Hofler9 invented a standing-wave ther-
moacoustic refrigerator, and demonstrated10 again that Rott’s approach to acoustics in small
channels was quantitatively accurate. In this type of refrigerator, the coupled oscillations
of gas motion, temperature, and heat transfer in the sound wave are phased in time so that
heat is absorbed from a load at low temperature and waste heat is rejected to a sink at
higher temperature. The offspring of Hofler’s refrigerator are still under study today.
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2.) Holfer refrigerator
http://www.ehponline.org/docs/1994/102-9/innovations.html
| Quote: | Someday, household refrigerators and air conditioners might be powered by loudspeakers blasting sound thousands of times more intense than the Rolling
Stones in concert.
"Thermoacoustic" refrigerators now under development use sound waves strong enough to make your hair catch fire, inventor Steven L. Garrett notes. But
don't worry--the noise is safely contained in a pressurized tube. If the tube shattered, the noise would instantly dissipate to harmless levels.
Because it conducts heat, such intense acoustic power is a clean, dependable replacement for cooling systems that use ozone-destroying
chlorofluorocarbons (CFCs), which will be banned after 31 December 1995, says Garrett, a physics professor at the Naval Postgraduate School in
Monterey, California.
Already, Garrett and NPS Research Assistant Professor Tom Hofler have developed a thermoacoustic refrigerator offering 200 watts of cooling power--a
level comparable to existing CFC-based refrigerators. Their "rock 'n' roll refrigerator" is cold enough to freeze ice or "simply keep beer chilled."
Hofler is also developing supercold "cryocoolers" capable of temperatures as low as -135°F (180°K). He hopes to achieve -243°F (120°K) because
such cryogenic temperatures would keep electronic components cool in space or speed the function of new microprocessors.
Skeptics say current thermoacoustic designs are inefficient compared to conventional refrigeration systems. But Garrett continues to improve his
invention, which requires only one moving part in the form of a loudspeaker and therefore may be more dependable than CFC-type refrigerators. It's
also more environmentally friendly, promising a route to "leap-frog over this whole chemical dependency problem," says Garrett, a 1993 winner of the
Rolex Foundation awards for enterprise in the applied sciences and invention, exploration, and discovery in the environment. |
Thank you!
Shingoshi
[Edited on 2009.7.21 by Shingoshi]
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not_important
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Humidifiers are not refrigerators, they simply get more water vapour into the air. They're more efficient than steamer type humidifiers because those
waste the energy involved in heating and boiling the water, going some 70 to 80 degrees hotter than the air the H2O is delivered to.
Thermoacoustic refrigerators do work, but as stated in your quotes are much less efficient the more conventional systems. They also operate in the
audio range, looking at their principles of operation will show you why. They are useful where their minimal number of moving parts gives them an
advantage that outweighs their low efficiency and generally large size. Most depend on very effective insulation as they can't pump much heat while
being reasonably sized. They can be a bugger to get to operate correctly, and the noise of poorly designed units can push you over the edge.
These folks are working on combining the reverse operation, heat into acoustic energy, with generating electricity and/or cooling using the
thermoacoustic effect - run your icebox on wood or cowpies.
http://www.score.uk.com/research/default.aspx
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12AX7
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Hmm, we already have that, the Einstein-Szilard refrigerator.
Tim
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not_important
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It's a bit easier to build than the Einstein-Szilard, being basically sheet metal and air.
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Shingoshi
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Correct me if I'm wrong...
Quote: Originally posted by not_important  | Humidifiers are not refrigerators, they simply get more water vapour into the air. They're more efficient than steamer type humidifiers because those
waste the energy involved in heating and boiling the water, going some 70 to 80 degrees hotter than the air the H2O is delivered to.
Thermoacoustic refrigerators do work, but as stated in your quotes are much less efficient the more conventional systems. They also operate in the
audio range, looking at their principles of operation will show you why. They are useful where their minimal number of moving parts gives them an
advantage that outweighs their low efficiency and generally large size. Most depend on very effective insulation as they can't pump much heat while
being reasonably sized. They can be a bugger to get to operate correctly, and the noise of poorly designed units can push you over the edge.
These folks are working on combining the reverse operation, heat into acoustic energy, with generating electricity and/or cooling using the
thermoacoustic effect - run your icebox on wood or cowpies.
http://www.score.uk.com/research/default.aspx
|
But doesn't the temperature of any fluid drop when actively made to evaporate? The one thing I keep reading about humidifiers, is the COOL moist air
that is generated. And I believe the same thing is happening to the fluid. I'm simply wanting to make a massive swamp cooler, in a small package.
And it is specifically the absence of moving parts that I'm after here.
Shingoshi
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Mr. Wizard
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Don't most computer power supplies have a switching circuit that is in the tens to hundreds of KHz and able to deliver hundreds of watts? If you were
to tap into that output transformer before it was rectified you could use it to drive a transducer, IF you could match up the impedance with a
piezoelectric or a nickel magnetostrictive transducer you would have it.
Tricking the switching supply into supplying without it's intended load is easy to do when you just want DC. I think you just put a small light bulb
across the 5 volt output lines to provide a little load. I've used a 12 volt panel bulb across the 5 Volt lines to power a 12 volt radio.
Even the oldest and junkiest oscilloscope should work well in that range to determine the frequency.
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Shingoshi
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Simply, Thank you!
| Quote: Originally posted by Mr. Wizard | Don't most computer power supplies have a switching circuit that is in the tens to hundreds of KHz and able to deliver hundreds of watts? If you were
to tap into that output transformer before it was rectified you could use it to drive a transducer, IF you could match up the impedance with a
piezoelectric or a nickel magnetostrictive transducer you would have it.
Tricking the switching supply into supplying without it's intended load is easy to do when you just want DC. I think you just put a small light bulb
across the 5 volt output lines to provide a little load. I've used a 12 volt panel bulb across the 5 Volt lines to power a 12 volt radio.
Even the oldest and junkiest oscilloscope should work well in that range to determine the frequency. |
This was quite helpful and informative. It's just the kind of thing that I need here.
The questions I have that really need to be answered;
1.) Are thermoacoustic refrigerators more efficient than a peltier?
2.) If so, are they significantly more efficient than the peltier?
Shingoshi
[Edited on 2009.7.21 by Shingoshi]
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Shingoshi
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Would either of these work as well...
| Quote: Originally posted by Mr. Wizard | Don't most computer power supplies have a switching circuit that is in the tens to hundreds of KHz and able to deliver hundreds of watts? If you were
to tap into that output transformer before it was rectified you could use it to drive a transducer, IF you could match up the impedance with a
piezoelectric or a nickel magnetostrictive transducer you would have it.
Tricking the switching supply into supplying without it's intended load is easy to do when you just want DC. I think you just put a small light bulb
across the 5 volt output lines to provide a little load. I've used a 12 volt panel bulb across the 5 Volt lines to power a 12 volt radio.
Even the oldest and junkiest oscilloscope should work well in that range to determine the frequency. |
I was wondering if a car amplifier would work as well? But if there are special requirements here, would the power circuitry of an old monitor have
what's needed?
Shingoshi
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Mr. Wizard
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I don't think car amplifiers would have the power at the >20KHz frequency you would need. I have been wrong before though.
When you talk about the 'power circuitry of an old monitor', are you referring to the high voltage flyback output? I don't think it has the power you
need. It also is above the audio bands (>20KHz), but designed to deliver high voltage at low power. The power supply of an old PC is much more
robust and capable of more output.
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12AX7
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The droplets liberated from the liquid, and in turn the air above the liquid, will be at a lower temperature, but the liquid itself is not
evaporating, it's being broken into droplets. Maybe there is a small effect from surface tension, but that would be the wrong direction (since you're
putting work into breaking surface tension, forming more surface area in the droplets). If you add a filter to collect the droplets and return them
to the bath, you will have a microscopic swamp cooler which will have the desired effect.
Really, what's wrong with a fan? One moving part. Works as good as anything.
Tim
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Shingoshi
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I wish I hadn't gotten rid of them...
| Quote: Originally posted by Mr. Wizard | I don't think car amplifiers would have the power at the >20KHz frequency you would need. I have been wrong before though.
When you talk about the 'power circuitry of an old monitor', are you referring to the high voltage flyback output? I don't think it has the power you
need. It also is above the audio bands (>20KHz), but designed to deliver high voltage at low power. The power supply of an old PC is much more
robust and capable of more output. |
Thanks to certain requirements I won't describe here, I had to get rid of many of the components I had available. Among them were a large number of
power supplies. Although, I think I still have a few left.
Where can I get specific instructions on how to go about this modification? I'm not exactly studied in electronics.
Shingoshi
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chemrox
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Is there a short cut to the specs for a unit one could make to drive reactions in say a 1L to 4L flask? I hate re-inventing the proverbial wheel.
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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stygian
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I recently caught the notion that one could potentially use antenna ferrites as a magnetostrictive element submersed in a reaction mixture in a vessel
surrounded by a coil. No idea how magnetostrictive said common ferrites are, and corrosion resistance would surely be an issure, but it was an idea.
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Shingoshi
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Explain this please...
| Quote: Originally posted by 12AX7 |
The droplets liberated from the liquid, and in turn the air above the liquid, will be at a lower temperature, but the liquid itself is not
evaporating, it's being broken into droplets. Maybe there is a small effect from surface tension, but that would be the wrong direction (since you're
putting work into breaking surface tension, forming more surface area in the droplets). If you add a filter to collect the droplets and return them
to the bath, you will have a microscopic swamp cooler which will have the desired effect.
Really, what's wrong with a fan? One moving part. Works as good as anything.
Tim |
I believe ultrasonic transducers cause the entire volume of a liquid to boil. That being the case, this would apply: | Quote: | http://en.wikipedia.org/wiki/Vaporization
Boiling is a phase transition from the liquid phase to gas phase that occurs at or above the temperature the boiling temperature. Note boiling
occurs below the surface. |
That being the case, there is no relevance of surface-tension here at all. I'm attempting to make the entire volume to boil.
Shingoshi
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