ULTRASOUND TECHNOLOGY

ULTRASOUND

• Ultrasound • is sound with a frequency greater than the upper limit

of human hearing

• Approximately > 18 kilohertz (18,000 hertz)

ULTRASOUND Applications

Application Frequency (KHz) Intensity

Cleaning 20- 40 Low

Medical Imaging 250-2000 Very Low

Laboratory 20-100 Medium

Industrial 20-30 High

Ultrasound Cleaning Applications• Often used for cleaning of

• Jewellery• Lenses and other optical parts• Coins• Watches• Dental instrument• surgical instruments• Fountain pens• Industrial parts• electronic equipment.

Ultrasound Cleaning Applications• Used in the

• Automotive• Sporting• Printing• Marine• Medical• Pharmaceutical• Electroplating• Engineering industries.

Medical Imaging• Used to visualize the

• Fetus• muscles• tendons• internal organs

• For their • Size• Structure• any pathological lesions.

• Obstetric sonography is commonly used during pregnancy.

• Frequency Range 250-2000 KHz

• In area of• Biology• Molecular Biology• Biochemistry• Biotechnology• Pharmaceutical

• Used for• Cell disruption • Homogenizing samples.• Dispersion & De-agglomeration• Reduction of primary particle to micron & sub-micron range

Laboratory Application

• Dispersion• Even distribution of fine particles in a medium (Stable or

unstable) Eg. Fumed silica Powder or Carbon Black.

• De-agglomeration• Breaking up of agglomerates is called de-agglomeration• An increase in available surface area can result in the increase

of the reactivity of reagents and catalysts.• The ultrasonic breakup of the agglomerate structures in

aqueous and non-aqueous suspensions allows to utilize the full potential of such materials.

Laboratory Application

• Cell Disruption ( Lysis)• Breaking up of cell walls for Isolation of DNA, RNA or proteins.

Eg. Muscle tissue, liver tissue or lymphocyte, separation of virus from Bacteria

• Other Methods used• Bead mill

• Cells are agitated in suspension with small abrasive particles. Cells break because of shear forces, grinding between beads, and collisions with beads.

• High Pressure Homogenizers• pumping of a slurry through a restricted orifice valve. They use

high pressure (up to 1500 bar) followed by an instant expansion through a special exiting nozzle

Laboratory Application

• Peizo Electric Effect• Piezoelectricity is based on the ability of certain crystals to emit an

electrical charge when mechanically loaded with pressure or tension

• Conversely, these crystals undergo a controlled deformation when exposed to an electric field – a behavior referred to as the inverse piezo effect.

• Peizo Ceramic Components are used in converting Electrical energy to Mechanical movement or oscillations.

• The oscillations are transferred by mechanical means to a sonotrode which is made to resonate.

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Laboratory Application

Industrial ApplicationsThe powerful industrial processors enables to treat liquid media on production scale.

• Dispersing and mixing• in resins• Paint• Ink• color pigments• Coatings e.g. fumed silica powder or carbon black

• Emulsifying • e.g. discontinuous phases

•from single or multiple feed• Fuel• Oil• Wax e.g. silicone oil

Industrial Applications• de-agglomerating and de-flocculation• nano-particles

•catalysts •chemicals •pharmaceuticals

• Homogenizing• elimination of settling • Wetting

(e.g. of colloidial silica)• particle size reduction/milling

•e.g to sub-micron ( nano) range• de-aeration and degassing

Industrial Applications• Sonochemistry is the application of ultrasound to

chemical reactions and processes realting to •increase in reaction speed •increase in reaction output •more efficient energy usage •switching of reaction pathway •performance improvement of phase transfer catalysts •avoidance of phase transfer catalysts •use of crude or technical reagents •activation of metals and solids •increase in the reactivity of reagents or catalysts

Industrial Applications•Nano sizing

•Nano materials are used in manufacture of sunscreens, electrically conductive coatings, and strong, lightweight plastic composites.•Nano materials fall into three broad categories:

metal oxides, nanoclays, and carbon nanotubes. •The goal of most powder-based processing has been smaller size and improving the uniformity of particles.•Particles of sub-micron sizes - so called nano particles - are now critical to advancements in numerous applications.

Industrial Applications• Food Processing

• ultrasonic extraction of phenolic compounds from vacuolar structures by disrupting plant tissue

• ultrasonic extraction of Betacyanin (red pigments, e.g. from beets) and Betaxanthin (yellow pigments)

• ultrasonic extraction of lipids and proteins from plant seeds, such as soybean (e.g. flour)

• ultrasonic improvement of oil extraction from oil seeds

• cell membrane permeabilization of fruits, such as grapes, plums, mango

• Food Processing• ultrasonic processing of

• fruit juices, e.g. orange, grapefruit, mango, grape, plum • purees • sauces, e.g. tomato, asparagus, bell pepper, mushroom • dairy products

• improve stability of dispersions, such as orange juice, i.e. reduce settling

Industrial Applications

• Paper Industry• Ultrasound can be used in manufacturing paper and in

paper recycling processes for:• preventing watermarks or lines that would reduce the

paper quality, by degassing the pulp• enhancing the fibrillation of the pulp fibres • replacement and/or enhancement of beating and/or

refining stages• using less energy than conventional beating

processes • fibre strength is maintained and chemical reactions

(such as TDF bleaching) are assisted

Industrial Applications

• enhancing the breakdown of wood chip into pulp or for the breakdown of used paper into pulp for reprocessing into recycled paper

•extracting of dirt, oil, printed inks (de-inking), colorants, or lacquer from paper during the process of recycling (fibre cleaning)

•Dewatering

•reduction of microbes in whitewater

•spaying liquids onto the manufactured paper (such as coating)

•homogenizing or dispersing of paper slurries

Industrial Applications

• Generator• Generates electrical oscillations of ultrasonic frequency (e.g. above

20kHz)

• Transducer• Electro-mechanical component, that converts electrical oscillations

into mechanical vibrations. • The electrical oscillations are generated by the generator. The

mechanical vibrations are transmitted to the sonotrode

• Sonotrode• Mechanical component, that transmits the ultrasonic vibrations

from the transducer to the material to be sonified.• It has to be mounted really tightly to avoid frictions and losses

Working principle of Sonicators.

Thank youCourtesy: Hielscher Ultrasonics GmbH