S. Berliner, III's berliner-ultrasonics.org Ultrasonics Page 6 keywords = " ultrasonic ultrasound cavitat ultraschall sonde ultrasonique sonotrode acoustic sonic sound wave ultra liquid processing Ultrasonic Industry Association UIA bubble shock wave clean immersi vapor degreas weld join bond sew seal solder insert stak drill grind machin cut extru form spin sonochemi react accelerat pollut abat toxi waste treat beneficiat remediat particl dispers disrupt homogeniz emulsif dissol degas foam defoam sparg phaco phaeco lithotript liposuct prophyla history Narda microwave fusion propulsi fluid filtration home.att.net "
Updated:  25 Mar 2016 17:20  ET
    [Created 19 Aug 2004;
original AT&T Worldnet Website begun 30 May 1996.]

Update info on the top on ALL pages for your convenience.
URL http://berliner-ultrasonics.org/uson-6.html
(formerly http://home.att.net/~Berliner-Ultrasonics/uson-6.html 
moved to this domain on 06 Mar 2010)

S. Berliner, III
Consultant in Ultrasonic Processing
"changing materials with high-intensity sound"


also see
Keywords (Applications) Index

[consultation is on a fee basis]

Specializing in brainstorming and devil's disciplery for new products and
reverse engineering and product improvement for existing products.


Technical and Historical Writer, Oral Historian
Popularizer of Science and Technology  

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Ultrasonics Page 6


PLEASE NOTE:  If some internal links refuse to work,
please click on Back and scroll down.

Ultrasonics Index

On the main Ultrasonics Page:

    Applications List.

    Probe-type Ultrasonic Processing Equipment.

    Quick Links to Major Ultrasonic Probe Manufacturers (moved to this page 10 Jul 2002).

    Brain Storming - bright ideas, pipe dreams, pie-in-the-sky?

On Ultrasonics Page A

        (A Layperson's Explanation of a Complex Letterhead).


On Ultrasonics Page 1:

        (A Non-Technical Explanation of "Cold Boiling"
      moved from the preceding page 12 Feb 00).


    TUBULAR HORNS (Radial Radiators).

    CARE of TIPS (Radiating Faces).

On Ultrasonics Page 1A:


    Free Bubbling.

    Bubble Entrapment.

    Foaming and Aerosoling - moved 28 May 02 to this Page 4.


    Call for Contributions for Book.

On Ultrasonics Page 2 (the next page):

    More on Cavitation.


On Ultrasonics Page 3:



    Keywords (Applications) Index.

    What's New?

On Ultrasonics Page 4:


    Foaming and Aerosoling - moved 28 May 02 from Page 1A.

    Ultrasonic Propulsion (Propulsive Force) - Moving Material.

    Ultrasonic Fountains - Atomization, Nebulization, Humidification,
        Misting, Particle Creation and Sizing.

    Ultrasonics and Nuclear Fusion.

    Boosters (Booster Horns).

    Quick Links to Major Ultrasonic Probe Manufacturers (moved to this page 10 Jul 2002).

On Ultrasonics Page 5:

    Ultrasonic Whistles (Nozzles, Atomizers, Nebulizers).

    AM-9 - The Use of Ultrasonic Probes in Fuel Research.

On Ultrasonics Page 6 (this page):
    Flow Through Horns.
    Explosion Resistance.
    ULTRASOUND - Sonar, Imaging, NDI/NDE, and HIFU
        including Railroads and Ultrasonics.   new.gif (25 Mar 2016)
    Quacks and Failures in Ultrasonics.

On Ultrasonics Page 7:

On the Ultrasonic Cleaning Page:

    Ultrasonic Cleaning {in process}.

    Immersible Transducers.

    What's New?


    ULTRASONICS GLOSSARY {in process}.

    Ultrasonic Bibliography Page 1 - Reference Books on Acoustics,
        Vibration, and Sound.
    Ultrasonic Bibliography Page 2 - Sonochemistry.
    Ultrasonic Bibliography Page 3 - Selected Articles.

You are invited to visit the ULTRASONIC INDUSTRY ASSOCIATION home page.

CALL FOR CONTRIBUTIONS:  I am writing a book on "High-Intensity Ultrasonic Technology and Applications", on the practical application of power (high intensity) ultrasonics, the use of ultrasonic energy to change materials.  Contributions are welcome (see below).


Larry Crum's Cavitation Bubble

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


Flow Through Horns

In the section on page 3 on
Continuous Flow Cells, reference is made to a Flow Through Horn, and one is included in the illustration, but let me expand upon that slightly here.  First, here is a stand-alone sketch of a flow through horn:

Flow Through Horn
(19 Aug 2004 sketch by and © 2004 S. Berliner, III all rights reserved)
Flow Through Horn

The circumferential collar which conducts fluid into the nodal point of the horn (and the seal grooves) can be left out and a small fluid fitting can be fastened directly to the horn (by the horn manufacturer!) if the mass of the horn is sufficient to ovecome any restrictive loading of the fitting (this must be done in the design/manufacturing phase; it can not be added to an existing horn).

Flow-through horns can be used to inject a fluid into a sample prior to or during sonication, as well as to withdraw sample during or after sonication.  They can also be used in sparging or aerosoling; contact your equipment supplier (or the author).

Explosion Resistance

As noted in Applications Monograph AM-7, ULTRASONIC DEGASSING, on continuation page 1, "Virtually no sonication devices are explosion-proof and only extreme measures can render them even explosion-resistant."  This a very serious matter; even the best-designed and best-built sonication unit could conceivably fail and, should that occur, it can sometimes be accompanied by a high-voltage arc inside the convertor.  While this poses no danger to the operator, per se, it could ignite vapors or flammable gases present in the operating environment.  Worse yet, should such an arc cause ignition inside a sealed or semi-sealed convertor housing, that enclosure would become, in effect, a BOMB.  For that reason, as well as the fact that the entire generator is electrically live, no one should ever use a standard sonicating unit in an explosive atmosphere without taking the "extreme" measures noted.  These measures can include using a specially-prepared convertor rendered "explosion-resistant", getting a second high-frequency cable used with an explosion resistant bulkhead connector, and placing the generator in an adjoining facility or in an explosion resistant enclosure.

The author has been able to get "explosion resistant" certifications for numerous installations following these simple precautions.  Schematically, a convertor has to be fabricated or modified to allow for a low-pressure inert gas feed:

Explosion-Resistant Convertor
(19 Aug 2004 sketch by and © 2004 S. Berliner, III all rights reserved)
Explosion-Resistant Convertor

Attention must be paid to the construction of the convertor (open frame or sealed) to assure that the inerting gas (usually nitrogen or argon) can lightly pressurize the case without blowing out seals or escaping too readily; such work is best done by (or in conjunction with) the manufacturer.

The generator must be isolated from the work area and the intervening wall or cabinet should be fitted with a gas-tight bulkhead connector rated for the same current and voltage (or higher) as the high-frequency cable itself.  A second high-frequency cable is used in series with the bulkhead connector and the regular cable:

Explosion-Resistant Set-Up
(19 Aug 2004 sketch by and © 2004 S. Berliner, III all rights reserved)
Explosion-Resistant Set-Up

Followng such relatively simple precautions should provide a reasonably safe environment, one which a safety inspector should be willing to certify as explosion-resistant.  Under NO forseeable circumstances would the author EVER undertake to guarantee such equipment, no matter how arranged, as explosion-proof (nor should it even be necessary in most practical circumstances).



Sonar, Imaging, NDT/NDI/NDE, and HIFU

Let us spend a moment delving into the areas of "ULTRASOUND" that are NOT covered under the umbrella of "Ultrasonics", the use of high-intensity acoustic energy to change materials (this topic is often requested when I lecture on ultrasonic processing).  I use the arbitrary semantic distinction between "ultrasonics" and "ultrasound" to cover these related, but vastly different, fields.  In both, acoustic energy is propagated by a transducer (electrostrictive or magnetostrictive) driven (most commonly) by an electronic generator or power supply.  The big difference comes in how that energy field is created and what it does.

In both ultrasonics and ultrasound, the energy is radiated outward at frequencies above human hearing, generally 20KHz (20,0000 cycles per second) and in both that frequency can range upwards into megahertz (MHz - a million or more cycles per second).

In ultrasonics, the energy field is created at very high intensity to change materials, deliberately to create cavitation in a liquid (for processing or cleaning) or to create friction to melt materials (welding and bonding).

In ultrasound, the energy field is created at low intensity to examine materials, without cavitation.  Among the many uses of ultrasound, the most common are sonar (Sound Navigation and Ranging, also known as echo-location), imaging, and NDT/NDI/NDE (non-destructive testing, inspection, or evaluation).  A signal is sent out, reflects back, and is detected.

In its most basic form, the time it takes for the signal to propagate, reflect, and return, can be interpreted as the distance from the radiating surface to the reflector.  In sonar, as used both by marine mammals, bats, and ships and submarines, the reflector can be food, enemies, or obstacles.  In fact, dolphins can actually determine the contents of another animal's stomach, so finely tuned are their echo-location and reception.  Changes in the medium (salt water vs. fresh, temperature gradients, static pressure, particulate suspensions, etc.) all contribute to background noise and degradation of signal but techniques have been developed to minimize their effects.

Two other widely-used applications of sonar are depth-finding and fish-finding; every commercial vessel and many private vessels carry one or both devices.

Similarly, the acoustic signal can be used to probe tissue (flesh) to generate multiple reflections which can then be assembled by computer to yield a two-dimensional, and even three-dimensional, picture of the area under examination.  The most commonly-known use is for mammography, examining the breast for tumors.  Tumors and other abnormalities yield images which differ from normal, healthy tissue and so can be detected.  Another ultrasound technique rapidly becoming well-known is the CAT scan (Computerized Axial Tomography), in which "slices" of the body are made by ultrasound and then assembled in the computer to generate a whole-body image.

Lastly, and least known to the general public, NDT/NDI/NDE (non-destructive testing or inspection or evaluation) has long been used to find flaws in materials, especially in metals (NDT and NDI have long been denigrated; NDE is the current term of art).  One very visible evidence of this is the ubiquitous yellow Sperry Rail Service cars* which run all over the railroads of the United States and Canada, probing the rails for defects by sending an ultrasound pulse out and measuring the distance to the crack or void from which the energy reflects.  Ultrasound testing is also used in all steel mills, in structural engineering, and in pipeline work.

There is a "grey" area where the two disciplines overlap; this is in medical applications.  Therapeutic ultrasound is the use of ultrasonics to heat tissue for relief from pain and inflammation.  Minimally-invasive surgery uses both imaging to locate the work and ultrasonic ablation and cutting to remove tissue and also for fat removal (liposuction).  HIFU (High-Intensity Focused Ultrasound) is a burgeoning discipline in which acoustic energy is focused to a point (much as a burning glass focuses light) to destroy tumors, prostate cancer, and kidney stones and gallstones, usually in conjunction with imaging.  In HIFU, the energy traverses intervening tissue without causing damage and then becomes concentrated and heats tissue at the focal point to destroy it.

A combination of radar and ultrasound was used early on to treat kidney stones; phased-array radar used many widely-spaced smaller radar stations to give broad coverage and yet very high resolution by focusing them on a common target.  Applying this technique to ultrasonics, kidney stones are exploded by immersing the body in a tank of water and focusing a large array of small transducers on the stone; convergence of the energy in the stone shatters it into pieces small enough to be passed naturally.

While these applications may use large amounts of energy (a large sonar array can use as much power as a small city), they generate the radiation at low intensity.  Even in HIFU, the energy leaves the radiating surface at low intensity.  The radiator ocscillates at low amplitude.  Quite to the contrary, ultrasonic processing equipment causes the radiating surface to oscillate at high amplitude.

To truly understand the full ramifications of acoustic energy, these fine distinctions should be noted.

In addition to the medical applications of ultrasound which overlap into ultrasonics, there are two widely-used areas of pure medical ultrasonics - these are dental prophylaxis (tartar removal by direct probe impact and gum treatment by ablation) and phæco-emulsification (removal of the lens by ablation in cataract surgery).  Not as widely used but equally effective is direct probe application in cautery and débridement of wounds and skin cancers.  Direct probe impact has also been used to break liver, kidney and gall stones as a minimally-invasive technique.

- - - * - - -

* - Anent NDT/NDE/NDI and Sperry Rail Service (and other such services), the author's personal domain now hosts major coverage of SRS and other ultrasonic flaw detection in trackwork at:   new.gif (25 Mar 2016)

Railroads and Ultrasonics.

Quacks and Failures in Ultrasonics.

There is a lighter, as well as a sadder, side to ultrasonics; I speak elsewhere of the ultrasonic oil burner, the ultrasonic carburet(t)or, and the ultrasonic dishwasher, all perfectly feasible, but all economically disastrous. However, the ultrasonic venetian blind cleaner, at which many of us had the galloping hee-haws, is very much a reality, often truck mounted to go to the point of use quickly and easily.  For all the great men, such as Lord Rayleigh and Norm Branson, who each made important contributions in their ways that changed our corner of history, there are ten or more that blew it.  One of those was the reclusive John Ernst Worrel Keeley (1827-1898), whose work on Sympathetic Vibration brought him more scorn than praise; yet, one wonders what he was up to.

Worrell and others like him are given brief bios at the Science Section of the Engine Room, a quirky site, but fun.

Dr. Wilhelm Reich, of Orgone Box fame/infamy, also seems to have his fling with acoustics.

Similarly, the famous Hermann Ludwig Ferdinand von Helmholtz oscillated (if you'll pardon the pun) from a brilliant world-renowned scientist to a reviled quack; he invented and built an acoustic resonator that also functioned as a motor and built a speedboat that functioned well on that principle but it never got anywhere (ooh, another pun).

And so it goes - one man's hero is another man's crackpot, one's genius another's idiot savant.

You may wish to visit the main ULTRASONICS page, et seq., with more on ultrasonics, as well as the Ultrasonics Cleaning page {in process} and the Ultrasonics Glossary page {also in process}.

Those persons interested in SONOCHEMISTRY might wish to look at the sonochemistry pages of:

    Prof. Kenneth S. Suslick of the University of Illinois at Urbana-Champaign, and

    Dr. Takahide Kimura at Shiga University in Japan.

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To tour the Ultrasonics pages in sequence, the arrows take you from the main Ultrasonics Page (with full index) to Pages A, 1, 1A, 2, 3, 4, 5, and this page 6, 7, Glossary Page, Cleaning Page, and Bibliography Pages 1, 2, 3, and 4 (see Index, above).

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