acoustic vibration creation

[hemagen]

I'd like to use acoustics to vibrate a fluid/solid mixture, hoping that it will cause the solid to break up or pulverize.
I cannot seem to find simple acoustic transducer output devices that I can vary frequency or amplitude. Any ideas on companies that make somthing that I can use?

 

[MikeyP]

Erm ... How about a loudspeaker?

M

--
Dr Michael F Platten

 

[tomirvine]

I had a lithotripsy procedure where external pressure pulses applied to my side were used to break up my kidney stone.

Tom Irvine

http://www.vibrationdata.com

 

[MikeHalloran]

If 'acoustic' means that the vibration energy is coupled from the transducer to the object by movement of air, you'll find that air is not a very effective coupling medium. A search on 'acoustic weapons' might give you a hint of the source energy levels that are required to produce physiological effects in remote subjects. Standing near a large single cylinder reciprocating compressor will give you a subjective feel. Standing near a large siren or ship horn is not recommended.

Acoustic imaging of fetuses, and lithotripsy, both use a liquid to couple energy from the transducer to the subject. Ultrasonic bonding, sewing, joining, etc., relies on intimate physical contact with some mechanical pressure applied.

On a large scale, bin vibrators do some of what you seem to seek.

You will not likely find a variable frequency/ variable amplitude exciter with serious power output.

Bin vibrators use a rotating eccentric mass; their frequency varies with motor rotation, but the rotor mass or eccentricity must be modified manually in order to adjust the amplitude.

Ultrasonic transducers typically use piezoelectric exciters, whose actual movement is exquisitely small and must be magnified by resonant solid horns. The horns are expensive, usually made from titanium, and only resonate at one frequency.

Air horns are also resonant. The valve/ diaphragm at their core is tuned for a particular frequency by controlling its tension and/or geometry, and the output is amplified by, well, a horn comprising a resonant cavity filled with air.

Your handle makes me suspect that you are trying to do this on a small scale, e.g. break up blood clots in a small tube or something like that. I suggest that you may need to arrive at your solution by experiment, e.g. by isolating a short section of rigid tube between flexible tube ends, and vibrating it laterally with a voice coil driver from a large commercial loudspeaker. With that, you can change the frequency with a VCO, and get more motion with a bigger amplifier. You may burn out a few coils along the way to finding an optimum frequency/amplitude combination. Then, design a low- power resonant device to do the same thing with less power at a fixed frequency.

Good luck.

And, ignore all that malarkey about electrons flowing in wires and such. All that electronic stuff works on smoke, sealed in at the factory. Proof: Let the smoke out, and it stops working. ;-)




Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

 

[hemagen]

Thanks for your input. I am investigating some of the ideas that have been suggested.
MH - you are right, I am trying to do this on a small scale (on the order of 1-4 cu in of solid material).
I'll let you know if I have any success or interesting failures.

 

[amorrison]

Googling using

acoustic pulverization

got some hits.