THE CAVITATION BUBBLE

[image from University of Washington, Applied Physics Laboratory (Lawrence Crum, Ph.D.)
- bubble diameter approximately 1mm]

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ULTRASONICS

[Please note that over the many years since this site was begun (30 May 1996), I have abandoned the formal academic usage of
"the author" and "your Webmaster" in favor of the more informal first person singular "I" and "me".]

There are other types of "ULTRASOUND", especially those used for Imaging and Sonar, Characterization of Materials and NDE (Non-Destructive Evaluation), pest-control (supposedly), and so forth; these do NOT change materials and are not covered herein.  This series of pages is concerned only with changing materials with ultrasonics.

Such change can clean, homogenize, and accelerate both physical and chemical reactions, among many other things.

That is a key phrase worthy of repetition:

PARTIAL LIST OF APPLICATIONS OF ULTRASONIC ENERGY
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BONDING OPERATIONS:
Welding - Joining - Sewing - Sealing - Insertion - Staking - Soldering

MACHINING OPERATIONS:
Drilling - Grinding - Cutting

FORMING, FORGING, and CASTING OPERATIONS:
Extruding - Spinning - Static and Continuous Casting

CHEMICAL and PHYSICAL OPERATIONS:
Sonochemistry - Reacting (physical and chemical) - Accelerating Reactions - Pollution Abatement - Toxic Waste Treatment - Beneficiation of Ores - Remediation - Particle Handling [dispersion, agglomeration, suspension, column packing, sinters, fine ceramics, electronic insulators (resistors, capacitors), 20% volume reduction] - Disruption/Sonolysis - Homogenization - Emulsification - Dissolution - Degassing - Bubble Fusion

CLEANING OPERATIONS:
Surface Cleaning, Preparation, and Treatment - Enhancement of Surfactancy and Detergency - Vapor Degreasing - Turbidity Measurement

MEDICAL/SURGICAL OPERATIONS:
Phaecoemulsification (cataract removal) - Dental Prophylaxis (scaling - tartar removal) - Lithotriptry (removal of liver or gall stones) - Liposuction - Debridement of Wounds - Surgery - Cautery

MEDICAL/THERAPEUTIC OPERATIONS:
"Diathermy" (deep heating) - Inhalation Therapy - Skin Cancer Treatment

AEROSOL OPERATIONS:
Humidification (lace, flour, Legionella) - Spray Drying - Evaporative Cooling - Carburetion and Combustors

MISCELLANEOUS OPERATIONS:
Levitation, Foaming (sparging) and Defoaming - Destructive and Constructive Testing (erosion, cleaning, accelerated corrosion and reaction) - Forensics and Archaeology [potsherds, bone cleaning, selective erosion (serial number restoration)]

PROCESSING

Those with a smattering of technical knowledge can go to CONDENSED GUIDE TO ULTRASONIC PROCESSING (A Layperson's Explanation of a Complex Letterhead).

A word here about the terms "Ultrasonic Processing" vs. "Ultrasonic Liquid Processing" - the former refers to any method of changing materials using ultrasonic (high-frequency acoustical) energy; the latter refers specifically to methods of changing materials using ultrasonic (high-frequency acoustical) energy in a liquid (a liquid to be processed or the parent liquor used to carry solids to be processed).  Some processing, such as drying and levitation, can be accomplished in air or other gaseous media.  I have denigrated the latter term ("Ultrasonic Liquid Processing") because, while the most common form of ultrasonic processing, it is too limited in scope and too limiting for the imagination.

CLEANING

ACTIVE TANKS

IMMERSIBLE TRANSDUCERS

Other forms of ultrasonic cleaning include Ultrasonic Vapor Degreasing, Surface Wave Technology for cleaning Printed Circuit Boards, and High-intensity Cleaning of Porous Media, Surfaces for NDE, and Deep Holes.

      abatement				fine particle dispersion

      acceleration			fluidization (Br. fluidisation)

      agglomeration			food dehydration

      agitation				forming

      atomization (Br. atomisation)	fractionation

      beneficiation			grinding

      biological cell disruption	homogenization (Br. homogenisation)

      bleaching				insertion

      blending				joining

      bonding				levitation

      catalysis				liquids processing

      cavitation			machining

      cell disruption, biological	mixing

      cleaning				nebulization (Br. nebulisation)

      compaction			particle size reduction

      curing				pollution abatement

      cutting				processing

      deagglomeration			reflowing (hot melt adhesive)

      deflocculating			scission

      degassing				separation

      degreasing			size reduction

      dehydration			soldering

      disaggregation			solids processing

      disintegration			solubilization (Br. solubilisation)

      dispersion			sonocatalysis

      disruption			sonochemistry

      dissociation			sonolysis

      dissolution			sonoluminescence

      drying				staking

      emulsification			streaming

      enhancement			surface processing (as in cleaning)

      erosion				surgical

      extraction			suspension

      fatigue testing			tissue disruption

      filtration enhancement		welding (metals, plastics)

In normal ultrasonic liquid processing, the tip is immersed in the sample and activated, with processing occurring in the sample liquid in the cavitation zone under the tip as shown in this diagram:   (04 Sep 2010)

Ultrasonic Liquid Processing Diagram
(Diagram 04 Oct 2010 by and © 2010 S. Berliner, III)

Convertor-Stack-Horn Layout
(electrostrictive shown)
[Click on picture for larger image]

[Material on Cup Horns and other specific types of probes moved to Page 4a.]

More about Probe-type Ultrasonic Processing Equipment and Frequency can be found on Page 4a.

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ULTRASONIC PROCESSING - AL-1C - CONDENSED GUIDE TO ULTRASONIC PROCESSING
      (A Layperson's Explanation of a Complex Letterhead) {and Business Card!}
          (Moved to Ultrasonics page A).

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ULTRASONIC PROCESSING:  AL-1P, A POPULARIZED GUIDE TO ULTRASONIC PROCESSING
      (A Non-Technical Explanation of a Complicated Letterhead)
          {Moved to Page A}.

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AL-1V - "A POPULARIZED GUIDE TO ULTRASONIC CAVITATION"
      (A Non-Technical Explanation of "Cold Boiling")
          moved to Ultrasonics Continuation Page 1A).

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Quick Links to Major Ultrasonic Probe Manufacturers

Brain Storming -

    Here is where I will put ideas that I have not tried or which have not been carried forward
      or for which I can not find substantiation in my capacious memory or voluminous files:

Grain refinement (grain as in crystalization, NOT food grasses) - I speak to this in a small way under ultrasonic processing of molten metals, but there is much work that might be (and may, indeed, have been) done in this area.  Gradual reduction of cavitation in a melt will/should result in far better grain structure, finer dendritic formation, and smaller grain size.

Similarly, coarse ice formation in water can/should be slowed or prevented and microcrystalline or amorphous ice result.

In 1989, the idea of achieving "cold" fusion in the collapsing cavitation bubble popped into my head during the Pons/Fleischman flap but they did not respond to my suggestion; as of 2002 it was under serious investigation (see Ultrasonics and Nuclear Fusion).

This is the stuff of dreams - the place of devil's disciplery - seek and ye shall find - ask away; hey, you never know (what pearls of wisdom or insight are trapped under all the decaying grey matter)!

However, there is this caveat: ultrasonic processing is a highly energy-intensive method and should only be considered when standard means are not effective.

Please note that a far-more detailed explanation of ultrasonic processing, as well as other technical literature, is available at no charge to consultation clients.  However, as what I believe to be a public service, I shall be adding more of my monographs on ultrasonics on this site; watch for them in the index (above).

You may wish to visit Continuation Page A, Continuation Page 1, Continuation Page 2, and Continuation Page 3 with more on ultrasonics, as well as the Ultrasonics Cleaning page {in process} and the Ultrasonics Glossary page {also in process}.

© Copyright S. Berliner, III - 2003, 2004, 2005, 2006, 2007, 2008, 2010, 2011, 2012  - all rights reserved.