Used for washing parts and assemblies of various equipment, welding various materials... Ultrasound is used to produce suspensions, liquid aerosols and emulsions. To obtain emulsions, for example, a mixer-emulsifier UGS-10 and other devices are produced. Methods based on the reflection of ultrasonic waves from the interface between two media are used in devices for hydro-localization, flaw detection, medical diagnostics, etc.

Among other possibilities of ultrasound, it should be noted its ability to process hard brittle materials to a given size. In particular, ultrasonic treatment is very effective in the manufacture of parts and holes of complex shape in such items as glass, ceramics, diamond, germanium, silicon, etc., the processing of which is difficult by other methods.

The use of ultrasound in the restoration of worn parts reduces the porosity of the deposited metal and increases its strength. In addition, warpage of elongated weld-on parts, such as engine crankshafts, is reduced.

Ultrasonic cleaning of parts

Ultrasonic cleaning of parts or objects is used before repair, assembly, painting, chrome plating and other operations. Its use is especially effective for cleaning parts with a complex shape and hard-to-reach places in the form of narrow slots, slots, small holes, etc.

Industry produces big number installations for ultrasonic cleaning differing design features, bath capacity and power, for example transistor ones: UZU-0.25 with an output power of 0.25 kW, UZG-10-1.6 with a power of 1.6 kW, etc., thyristor UZG-2-4 with an output power of 4 kW and UZG-1-10 / 22 with a power of 10 kW. The operating frequency of the installations is 18 and 22 kHz.

Ultrasonic installation UZU-0.25 is designed for cleaning small parts. It consists of an ultrasonic generator and an ultrasonic bath.

Technical data of the ultrasonic unit UZU-0.25

Mains frequency - 50 Hz

Power consumed from the network - no more than 0.45 kVA

Operating frequency - 18 kHz

Output power - 0.25 kW

Internal dimensions of the working bath - 200 x 168 mm with a depth of 158 mm

On the front panel of the ultrasonic generator there is a toggle switch for switching on the generator and a lamp signaling the presence of supply voltage.

On the rear wall of the generator chassis there are: a fuse holder and two plug connectors, through which the generator is connected to the ultrasonic bath and the mains, a terminal for the generator ground.

Three packaged piezoelectric transducers are mounted in the bottom of the ultrasonic bath. The package of one transducer consists of two piezoelectric plates made of TsTS-19 material (lead zirconate titanate), two frequency-reducing pads and a central stainless steel rod, the head of which is the transducer's emitting element.

On the casing of the bath there are: a fitting, a tap handle with the inscription "Drain", a terminal for grounding the bath and a plug connector for connecting to a generator.

Figure 1 shows the principal electrical circuit ultrasonic installation UZU-0.25.

Rice. 1. Schematic diagram of the ultrasonic installation UZU-0.25

The first stage is, operating on a transistor VT1 according to a circuit with an inductive feedback and an oscillating circuit.

Electrical vibrations of an ultrasonic frequency of 18 kHz, which occur in the master oscillator, are fed to the input of the power preamplifier.

The preliminary power amplifier consists of two stages, one of which is assembled on transistors VT2, VT3, the second - on transistors VT4, VT5. Both stages of power pre-amplification are assembled according to a sequential push-pull circuit operating in a switching mode. The key operating mode of transistors allows obtaining high efficiency at a sufficiently high power.

Base circuits of transistors VT2, VT3. VT4, VT5 are connected to separate, opposite windings of transformers TV1 and TV2. This ensures push-pull operation of the transistors, that is, alternate switching on.

Automatic biasing of these transistors is provided by resistors R3 - R6 and capacitors C6, C7 and C10, C11, included in the base circuit of each transistor.

The alternating excitation voltage is supplied to the base through the capacitors C6, C7 and C10, C11, and the constant component of the base current, passing through the resistors R3 - R6, creates a voltage drop across them, which ensures reliable closing and opening of the transistors.

The fourth stage is the power amplifier. It consists of three push-pull cells on transistors VT6 - VT11, operating in switching mode. The voltage from the preamplifier is supplied to each transistor from a separate winding of the transformer TV З, and in each cell these voltages are antiphase. From the transistor cells, the alternating voltage is applied to the three windings of the TV4 transformer, where the power is added.

From the output transformer, the voltage is fed to the piezoelectric transducers AA1, AA2 and AAAZ.

Since the transistors operate in switching mode, the output voltage containing harmonics is rectangular. To isolate the first harmonic of the voltage on the converters, a coil L is connected in series with the converters to the output winding of the transformer TV4, the inductance of which is calculated in such a way that with its own capacitance of the converters it forms an oscillatory circuit tuned to the 1st harmonic of the voltage. This makes it possible to obtain a sinusoidal voltage across the load without changing the energetically favorable mode of the transistors.

The installation is powered from an alternating current with a voltage of 220 V with a frequency of 50 Hz using a power transformer TV5, which has a primary winding and three secondary windings, one of which serves to power the master generator, and the other two serve to power the remaining stages.

The master generator is powered by a rectifier assembled by (VD1 and VD2 diodes).

The power supply of the preliminary amplification stages is carried out from a rectifier assembled in a bridge circuit (diodes VD3 - VD6). The second bridge circuit on diodes VD7 - VD10 feeds the power amplifier.

A cleaning medium should be selected depending on the nature of the dirt and the materials. If trisodium phosphate is not available, soda ash can be used to clean steel parts.

The cleaning time in an ultrasonic bath ranges from 0.5 to 3 minutes. The maximum permissible temperature of the cleaning medium is 90 o C.

Before changing the washing liquid, the generator should be turned off, not allowing the converters to operate without liquid in the bath.

The cleaning of parts in an ultrasonic bath is carried out in the following sequence: the power switch is set to the "Off" position, the drain valve of the bath is set to the "Closed" position, the cleaning medium is poured into the ultrasonic bath to a level of 120 - 130 mm, the power cable plug is plugged into an electrical outlet. mains voltage 220 V.

Testing the installation: turn on the toggle switch to the "On" position, while the signal lamp should light up and a working sound of the cavitating liquid should appear. The appearance of cavitation can also be judged by the formation of the smallest movable bubbles on the bath transducers.

After testing the installation, disconnect it from the mains, load contaminated parts into the bath and start processing.

Ultrasonic installations designed for processing various parts with a powerful ultrasonic acoustic field in a liquid medium. The units UZU4-1.6 / 0 and UZU4M-1.6 / 0 allow solving the problems of fine cleaning of filters of fuel and hydraulic oil systems from carbon deposits, resinous substances, oil coking products, etc. The cleaned filters actually acquire a second life. Moreover, they can be subjected to ultrasonic treatment several times. Installations are also available low power UZSU series for cleaning and ultrasonic surface treatment of various parts. Ultrasonic cleaning processes are required in the electronic, instrument-making industry, aviation, rocket and space technology and wherever high technologically pure technologies are required.

Installations UZU 4-1,6-0 and UZU 4M-1,6-0

Ultrasonic cleaning of various filters of aircraft from resinous substances and coking products.

This method of processing is based on mechanical action on the material. It is called ultrasonic because the frequency of impacts corresponds to the range of inaudible sounds (f = 6-10 5 kHz).

Sound waves are mechanical elastic vibrations that can only propagate in an elastic medium.

When a sound wave propagates in an elastic medium, material particles perform elastic vibrations around their positions at a speed that is called oscillatory.

Thickening and thinning of the medium in a longitudinal wave is characterized by an excess, the so-called sound pressure.

The speed of propagation of a sound wave depends on the density of the medium in which it moves. When propagating in a material environment, a sound wave carries energy, which can be used in technological processes.

Advantages of ultrasonic treatment:

The possibility of obtaining acoustic energy by various techniques;

Wide range of ultrasound applications (from sizing to welding, brazing, etc.);

Ease of automation and operation;

Flaws:

Increased cost of acoustic energy compared to other types of energy;

The need to manufacture generators of ultrasonic vibrations;

The need to manufacture special tools with special properties and shape.

Ultrasonic vibrations are accompanied by a number of effects that can be used as basic ones for the development of various processes:

Cavitation, i.e. the formation of bubbles in the liquid and their bursting.

In this case, large local instantaneous pressures arise, reaching 10 8 N / m2;

Absorption of ultrasonic vibrations by a substance, in which part of the energy is converted into heat, and part is spent on changing the structure of the substance.

These effects are used to:

Separation of molecules and particles of different masses in heterogeneous suspensions;

Coagulation (enlargement) of particles;

Dispersing (crushing) a substance and mixing it with others;

Degassing of liquids or melts due to the formation of large floating bubbles.

1.1. Elements of ultrasonic installations

Any ultrasonic device (USU) includes three main elements:

Source of ultrasonic vibrations;

Acoustic speed transformer (hub);

Fastening details.

Sources of ultrasonic vibrations (UZK) can be of two types - mechanical and electrical.

Mechanical converts mechanical energy, for example, the speed of movement of a liquid or gas. These include ultrasonic sirens or whistles.

Electric sources of ultrasonic testing convert electrical energy into mechanical elastic vibrations of the corresponding frequency. There are electrodynamic, magnetostrictive and piezoelectric transducers.

The most widely used are magnetostrictive and piezoelectric transducers.

The principle of operation of magnetostrictive transducers is based on the longitudinal magnetostrictive effect, which manifests itself in a change in the length of a metal body made of ferromagnetic materials (without changing their volume) under the influence of a magnetic field.

The magnetostrictive effect is different for different materials. Nickel and permendur (an alloy of iron with cobalt) have high magnetostriction.

The package of a magnetostrictive transducer is a core made of thin plates, on which a winding is placed to excite an alternating electromagnetic field of a high frequency in it.

The principle of operation of piezoelectric transducers is based on the ability of some substances to change their geometric dimensions (thickness and volume) in an electric field. The piezoelectric effect is reversible. If a plate made of piezoelectric material is subjected to compression or tension deformation, then electric charges will appear on its edges. If the piezoelectric element is placed in a variable electric field, then it will deform, exciting in environment ultrasonic vibrations. A vibrating plate made of piezoelectric material is an electromechanical transducer.

Piezoelements based on barium titanium, lead zirconate-titanium are widely used.

Acoustic speed transformers (concentrators of longitudinal elastic vibrations) can have different shape(fig. 1.1).

Rice. 1.1. Hub shapes

They serve to match the parameters of the transducer with the load, to attach the vibrating system and to introduce ultrasonic vibrations into the area of ​​the processed material. These devices are rods of various cross-sections, made of materials with corrosion and cavitation resistance, heat resistance, resistance to aggressive media.

1.2. Technological use ultrasonic vibrations

In industry, ultrasound is used in three main areas: force action on material, intensification and ultrasonic testing processes.

Forceful action on the material

It is applied for mechanical processing hard and superhard alloys, obtaining stable emulsions, etc.

The most commonly used are two types of ultrasonic treatment at characteristic frequencies of 16-30 kHz:

Dimensional processing on machine tools using tools;

Cleaning in baths with a liquid medium.

The main working mechanism of the ultrasonic machine is the acoustic unit (Fig. 1.2). It is designed to set the working tool in vibrational motion. The acoustic unit is powered by an electric oscillator (usually a lamp), to which winding 2 is connected.

The main element of the acoustic unit is a magnetostrictive (or piezoelectric) converter of the energy of electrical vibrations into the energy of mechanical elastic vibrations - vibrator 1.

Rice. 1.2. Acoustic unit of ultrasonic installation

The vibrations of the vibrator, which is variably lengthened and shortened with an ultrasonic frequency in the direction of the magnetic field of the winding, are amplified by a concentrator 4 attached to the end of the vibrator.

A steel tool 5 is attached to the concentrator so that a gap remains between its end and the workpiece 6.

The vibrator is placed in an ebonite casing 3, where running cooling water is supplied.

The tool must be in the shape of the specified hole section. A liquid with the smallest grains of abrasive powder is supplied to the space between the end face of the tool and the workpiece surface being processed from the nozzle 7.

From the vibrating end face of the tool, the abrasive grains acquire a high speed, hit the surface of the part and knock out the smallest chips from it.

Although the productivity of each blow is negligible, the productivity of the installation is relatively high, which is due to the high vibration frequency of the tool (16-30 kHz) and the large number of abrasive grains moving simultaneously with high acceleration.

As the layers of material are removed, the tool is automatically fed.

The abrasive fluid is fed into the processing area under pressure and flushes out processing waste.

With the help of ultrasonic technology, operations such as piercing, chiselling, drilling, cutting, grinding and others can be performed.

Ultrasonic baths (Fig. 1.3) are used to clean surfaces metal parts from corrosion products, oxide films, mineral oils, etc.

The operation of an ultrasonic bath is based on the use of the effect of local hydraulic shocks that occur in a liquid under the action of ultrasound.

The principle of operation of such a bath is as follows: the workpiece (1) is immersed in a tank (4) filled with a liquid detergent medium (2). The emitter of ultrasonic vibrations is a diaphragm (5) connected to a magnetostrictive vibrator (6) using an adhesive composition (8). The bath is installed on a base (7). Waves of ultrasonic vibrations (3) propagate in working area where the processing takes place.

Rice. 1.3. Ultrasonic bath

Ultrasonic cleaning is most effective when removing contaminants from hard-to-reach cavities, depressions and small channels. In addition, this method manages to obtain stable emulsions of such liquids immiscible by conventional methods as water and oil, mercury and water, benzene and others.

Ultrasonic equipment is relatively expensive, therefore it is economically expedient to use ultrasonic cleaning of small-sized parts only in conditions of mass production.

Intensification of technological processes

Ultrasonic vibrations significantly change the course of some chemical processes. For example, polymerization at a certain sound intensity is more intense. With a decrease in the strength of sound, the reverse process is possible - depolymerization. Therefore, this property is used to control the polymerization reaction. By changing the frequency and intensity of ultrasonic vibrations, you can provide the required reaction rate.

In metallurgy, the introduction of elastic oscillations of ultrasonic frequency into melts leads to a significant crushing of crystals and an acceleration of the formation of build-ups during crystallization, a decrease in porosity, an increase in the mechanical properties of solidified melts and a decrease in the content of gases in metals.

Ultrasonic process control

With the help of ultrasonic vibrations, it is possible to continuously monitor the progress of the technological process without carrying out laboratory analyzes samples. For this purpose, the dependence of the parameters of the sound wave on physical properties environment, and then by the change in these parameters after the action on the environment with sufficient accuracy to judge its state. As a rule, low-intensity ultrasonic vibrations are used.

By changing the energy of the sound wave, it is possible to control the composition of various mixtures that are not chemical compounds. The speed of sound in such media does not change, and the presence of suspended matter impurities affects the absorption coefficient of sound energy. This makes it possible to determine the percentage of impurities in the starting material.

By the reflection of sound waves at the interface between the media ("transillumination" with an ultrasonic beam), it is possible to determine the presence of impurities in the monolith and create ultrasonic diagnostic devices.

Conclusions: ultrasound - elastic waves with a vibration frequency from 20 kHz to 1 GHz, inaudible human ear... Ultrasonic installations are widely used for processing materials due to high-frequency acoustic vibrations.

Holders of the patent RU 2286216:

The invention relates to devices for ultrasonic cleaning and processing of suspensions in powerful acoustic fields, in particular for dissolution, emulsification, dispersion, as well as devices for receiving and transmitting mechanical vibrations using the effect of magnetostriction. The installation contains an ultrasonic rod magnetostrictive transducer, a working chamber made in the form of a metal cylindrical pipe, and an acoustic waveguide, the emitting end of which is hermetically connected to the bottom of the cylindrical pipe by means of an elastic sealing ring, and the receiving end of this waveguide is acoustically rigidly connected to the emitting surface of the ultrasonic rod transducer ... An annular magnetostrictive emitter is additionally introduced into the installation, the magnetic circuit of which is acoustically rigidly pressed onto the tube of the working chamber. The ultrasonic installation forms a two-frequency acoustic field in the processed liquid medium, which provides an increase in the intensification of the technological process without reducing the quality of the final product. 3 C.p. f-ly, 1 dwg

The invention relates to devices for ultrasonic cleaning and processing of suspensions in powerful acoustic fields, in particular for dissolution, emulsification, dispersion, as well as devices for receiving and transmitting mechanical vibrations using the effect of magnetostriction.

A device is known for introducing ultrasonic vibrations into a liquid (DE patent No. 3815925, V 08 V 3/12, 1989) by means of an ultrasonic sensor, which is fixed with a sound-emitting cone by means of a hermetically insulating flange in the bottom zone inside the liquid bath.

The closest technical solution to the proposed is an ultrasonic installation of the type UZVD-6 (A.V. Donskoy, OKKeller, G.S.Kratysh "Ultrasonic electrotechnological installations", Leningrad: Energoizdat, 1982, p. 169), containing a rod ultrasonic transducer, a working chamber made in the form of a metal cylindrical pipe, and an acoustic waveguide, the emitting end of which is hermetically connected to the lower part of the cylindrical pipe by means of an elastic sealing ring, and the receiving end of this waveguide is acoustically rigidly connected to the emitting surface of the rod ultrasonic transducer.

The disadvantage of the identified known ultrasonic installations is that the working chamber has a single source of ultrasonic vibrations, which are transmitted to it from the magnetostrictive transducer through the end of the waveguide, the mechanical properties and acoustic parameters of which determine the maximum allowable radiation intensity. Often, the received intensity of radiation of ultrasonic vibrations cannot meet the requirements of the technological process in relation to the quality of the final product, which makes it necessary to extend the time of ultrasonic treatment of the liquid medium and leads to a decrease in the intensity of the technological process.

Thus, the ultrasonic devices, analogue and prototype of the claimed invention identified in the course of the patent search, when implemented, do not ensure the achievement of the technical result, which consists in increasing the intensification of the technological process without reducing the quality of the final product.

The proposed invention solves the problem of creating an ultrasonic installation, the implementation of which ensures the achievement of the technical result, which consists in increasing the intensification of the technological process without reducing the quality of the final product.

The essence of the invention lies in the fact that in an ultrasonic installation containing a rod ultrasonic transducer, a working chamber made in the form of a metal cylindrical pipe, and an acoustic waveguide, the emitting end of which is hermetically connected to the bottom of the cylindrical pipe by means of an elastic sealing ring, and the receiving end of this waveguide acoustically rigidly connected to the emitting surface of the rod ultrasonic transducer; additionally, an annular magnetostrictive emitter is introduced, the magnetic circuit of which is acoustically rigidly pressed onto the tube of the working chamber. In addition, an elastic sealing ring is attached to the radiating end of the waveguide in the area of ​​the displacement assembly. In this case, the lower end of the magnetic circuit of the annular radiator is located in the same plane with the radiating end of the acoustic waveguide. Moreover, the surface of the radiating end of the acoustic waveguide is made concave, spherical, with a sphere radius equal to half the length of the magnetic circuit of the annular magnetostrictive emitter.

The technical result is achieved as follows. A rod ultrasonic transducer is a source of ultrasonic vibrations that provide required parameters the acoustic field in the working chamber of the installation for performing the technological process, which ensures the intensification and quality of the final product. An acoustic waveguide, the emitting end of which is hermetically connected to the bottom of the cylindrical pipe, and the receiving end of this waveguide is acoustically rigidly connected to the emitting surface of the ultrasonic rod transducer, provides the transmission of ultrasonic vibrations into the processed liquid medium of the working chamber. In this case, the tightness and mobility of the connection is ensured due to the fact that the radiating end of the waveguide is connected to the lower part of the working chamber tube by means of an elastic sealing ring. The mobility of the connection provides the possibility of transferring mechanical vibrations from the transducer through the waveguide to the working chamber, into the liquid processed medium, the possibility of performing the technological process, and, consequently, obtaining the required technical result.

In addition, in the claimed installation, the elastic sealing ring is fixed at the emitting end of the waveguide in the zone of the displacement node, in contrast to the prototype, in which it is installed in the zone of the displacement antinode. As a result, in the prototype installation, the O-ring dampens vibrations and reduces the Q-factor of the vibrating system, and therefore reduces the intensity of the technological process. In the declared installation, the O-ring is installed in the area of ​​the displacement unit, so it does not affect the vibrating system. This allows you to pass more power through the waveguide compared to the prototype and thereby increase the radiation intensity, therefore, intensify technological process without compromising the quality of the final product. In addition, since in the claimed installation the O-ring is installed in the area of ​​the assembly, i.e. in the zone of zero deformations, it does not collapse from vibrations, retains the mobility of the connection of the radiating end of the waveguide with bottom pipes of the working chamber, which allows you to maintain the radiation intensity. In the prototype, the sealing ring is installed in the zone of maximum deformation of the waveguide. Therefore, the ring gradually collapses from vibrations, which gradually reduces the radiation intensity, and then breaks the tightness of the connection and disrupts the operation of the installation.

The use of an annular magnetostrictive emitter allows realizing a high conversion power and a significant radiation area (A.V. Donskoy, OK Keller, G.S. intensification of the technological process without reducing the quality of the final product.

Since the pipe is cylindrical, and the magnetostrictive emitter introduced into the installation is made annular, it is possible to press the magnetic core onto the outer surface of the pipe. When the supply voltage is applied to the winding of the magnetic wire, a magnetostrictive effect occurs in the plates, which leads to deformation of the annular plates of the magnetic circuit in the radial direction. In this case, due to the fact that the pipe is made of metal, and the magnetic circuit is acoustically rigidly pressed onto the pipe, the deformation of the annular plates of the magnetic circuit is transformed into radial oscillations of the pipe wall. As a result, the electrical vibrations of the exciting generator of the annular magnetostrictive emitter are converted into radial mechanical vibrations of the magnetostrictive plates, and due to the acoustically rigid connection of the radiation plane of the magnetic circuit with the pipe surface, mechanical vibrations are transmitted through the pipe walls into the processed liquid medium. In this case, the source of acoustic vibrations in the processed liquid medium is the inner wall of the cylindrical tube of the working chamber. As a result, an acoustic field with a second resonant frequency is formed in the claimed installation in the treated liquid medium. In this case, the introduction of an annular magnetostrictive emitter in the claimed installation increases, in comparison with the prototype, the area of ​​the emitting surface: the emitting surface of the waveguide and part of the inner wall of the working chamber, on the outer surface of which an annular magnetostrictive emitter is pressed. An increase in the area of ​​the radiating surface increases the intensity of the acoustic field in the working chamber and, therefore, makes it possible to intensify the technological process without reducing the quality of the final product.

The location of the lower end of the magnetic circuit of the annular radiator in the same plane with the radiating end of the acoustic waveguide is the best option, since its placement below the radiating end of the waveguide leads to the formation of a dead (stagnant) zone for the ring transducer (ring radiator - pipe). Placing the bottom end of the magnetic circuit of the annular radiator above the radiating end of the waveguide reduces the efficiency of the annular converter. Both options lead to a decrease in the intensity of the effect of the total acoustic field on the processed liquid medium, and, consequently, to a decrease in the intensification of the technological process.

Since the emitting surface of the annular magnetostrictive emitter is a cylindrical wall, the sound energy is focused, i.e. the concentration of the acoustic field is created along the axial line of the pipe, onto which the magnetic core of the emitter is pressed. Since the emitting surface of the ultrasonic rod transducer is made in the form of a concave sphere, this emitting surface also focuses the sound energy, but near a point that lies on the centerline of the pipe. Thus, at different focal lengths, the foci of both emitting surfaces coincide, concentrating powerful acoustic energy in a small volume of the working chamber. Since the lower end of the magnetic circuit of the annular radiator is located in the same plane with the radiating end of the acoustic waveguide, in which the concave sphere is made with a radius equal to half the length of the magnetic circuit of the annular magnetostrictive radiator, the focusing point of the acoustic energy lies in the middle of the axial line of the pipe, i.e. in the center of the working chamber of the installation powerful acoustic energy is concentrated in a small volume ("Ultrasound. Little Encyclopedia", chief ed. I.P. Golyanin, Moscow: Soviet encyclopedia, 1979, pp. 367-370). In the area of ​​focusing the acoustic energies of both emitting surfaces, the intensity of the effect of the acoustic field on the processed liquid medium is hundreds of times higher than in other areas of the chamber. A local volume is created with a powerful intensity of exposure to the field. Due to the local powerful intensity of the impact, even difficult-to-machine materials are destroyed. In addition, in this case, powerful ultrasound is diverted from the walls, which protects the walls of the chamber from destruction and contamination of the processed material by the product of wall destruction. Thus, making the surface of the radiating end of the acoustic waveguide concave, spherical, with a sphere radius equal to half the length of the magnetic circuit of the annular magnetostrictive emitter, increases the intensity of the effect of the acoustic field on the processed liquid medium, and, consequently, provides intensification of the technological process without reducing the quality of the final product.

As shown above, in the claimed installation, an acoustic field with two resonance frequencies is formed in the treated liquid medium. The first resonant frequency is determined by the resonant frequency of the rod magnetostrictive transducer, the second - by the resonant frequency of the ring magnetostrictive emitter pressed onto the tube of the working chamber. The resonant frequency of the annular magnetostrictive emitter is determined from the expression lcp = λ = c / fres, where lcp is the length of the center line of the magnetic circuit of the emitter, λ is the wavelength in the material of the magnetic circuit, c is the speed of elastic vibrations in the material of the magnetic circuit, fres is the resonant frequency of the emitter (A. Donskoy, OKKeller, G.S.Kratysh "Ultrasonic electrotechnological installations", Leningrad: Energoizdat, 1982, p. 25). In other words, the second resonant frequency of the installation is determined by the length of the center line of the annular magnetic circuit, which in turn is determined by the outer diameter of the working chamber pipe: the longer the center line of the magnetic circuit, the lower the second resonant frequency of the installation.

The presence of two resonant frequencies in the declared installation allows to intensify the technological process without reducing the quality of the final product. This is explained as follows.

Under the action of an acoustic field in the processed liquid medium, acoustic flows arise - stationary vortex flows of a liquid that arise in a free inhomogeneous sound field. In the declared installation in the processed liquid medium, two types of acoustic waves are formed, each with its own resonant frequency: a cylindrical wave propagates radially from inner surface pipes (working chamber), and a plane wave propagates along the working chamber from bottom to top. The presence of two resonant frequencies enhances the effect of acoustic flows on the processed liquid medium, since at each resonance frequency its own acoustic flows are formed, which intensively mix the liquid. This also leads to an increase in the turbulence of acoustic flows and to an even more intensive mixing of the processed liquid, which increases the intensity of the effect of the acoustic field on the processed liquid medium. As a result, the technological process is intensified without reducing the quality of the final product.

In addition, under the influence of the acoustic field in the processed liquid medium, cavitation occurs - the formation of ruptures of the liquid medium where there is a local decrease in pressure. As a result of cavitation, vapor-gas cavitation bubbles are formed. If the acoustic field is weak, the bubbles resonate, pulsate in the field. If the acoustic field is strong, the bubble collapses after the period of the sound wave (ideal case), since it falls into the region of high pressure created by this field. When the bubbles collapse, they generate strong hydrodynamic disturbances in the liquid medium, intense radiation of acoustic waves and cause destruction of the surfaces of solids bordering on the cavitating liquid. In the claimed installation, the acoustic field is more powerful than the acoustic field of the prototype installation, which is explained by the presence of two resonant frequencies in it. As a result, in the claimed installation, the probability of collapse of cavitation bubbles is higher, which enhances cavitation effects and increases the intensity of the effect of the acoustic field on the processed liquid medium, and therefore provides an intensification of the technological process without reducing the quality of the final product.

The lower the resonant frequency of the acoustic field, the larger the bubble, since the period at the low frequency is large and the bubbles have time to grow. The life of a bubble during cavitation is one period of frequency. When the bubble collapses, it creates powerful pressure. The larger the bubble, the more high pressure is created when it is slammed. In the declared ultrasonic installation, due to the two-frequency sounding of the processed liquid, cavitation bubbles differ in size: larger ones are the result of exposure to a liquid medium of low frequency, and small ones - of high frequency. When cleaning surfaces or processing a suspension, small bubbles penetrate into cracks and cavities of solid particles and, collapsing, form micro-shock effects, weakening the integrity of a solid particle from the inside. Larger bubbles, collapsing, provoke the formation of new microcracks in solid particles, further weakening the mechanical bonds in them. The solid particles are destroyed.

During emulsification, dissolution and mixing, large bubbles destroy intermolecular bonds in the components of the future mixture, shortening the chains, and form conditions for small bubbles for further destruction of intermolecular bonds. As a result, the intensification of the technological process increases without reducing the quality of the final product.

In addition, in the claimed installation, as a result of the interaction of acoustic waves with different resonance frequencies in the treated liquid medium, beats occur due to the superposition of two frequencies (the principle of superposition), which cause a sharp instantaneous increase in the amplitude of the acoustic pressure. At such moments, the impact power of the acoustic wave can be several times higher than the specific power of the installation, which intensifies the technological process and not only does not reduce, but improves the quality of the final product. In addition, a sharp increase in the amplitude of the acoustic pressure facilitates the supply of cavitation nuclei to the cavitation zone; cavitation increases. Cavitation bubbles, forming in pores, irregularities, surface cracks solid in suspension form local acoustic currents, which intensively mix the liquid in all microvolumes, which also makes it possible to intensify the technological process without reducing the quality of the final product.

Thus, from the foregoing it follows that the claimed ultrasonic installation, due to the possibility of forming a two-frequency acoustic field in the treated liquid medium, when implemented, ensures the achievement of the technical result, which consists in increasing the intensification of the technological process without reducing the quality of the final product: the results of cleaning surfaces, dispersing solid components in a liquid, the process of emulsification, mixing and dissolution of the components of the liquid medium.

The drawing shows the declared ultrasonic installation. The ultrasonic installation contains an ultrasonic rod magnetostrictive transducer 1 with an emitting surface 2, an acoustic waveguide 3, a working chamber 4, a magnetic core 5 of an annular magnetostrictive emitter 6, an elastic sealing ring 7, a pin 8. Holes 9 are provided in the magnetic core 5 for performing an excitation winding (not shown) ... The working chamber 4 is made in the form of a metal, for example steel, cylindrical pipe. In an example of the installation, the waveguide 3 is made in the form of a truncated cone, in which the emitting end 10 by means of an elastic sealing ring 7 is hermetically connected to the lower part of the tube of the working chamber 4, and the receiving end 11 is axially connected by a pin 8 with the emitting surface 2 of the converter 1. Magnetic core 5 made in the form of a package of magnetostrictive plates in the form of rings, and acoustically rigidly pressed onto the pipe of the working chamber 4; in addition, the magnetic circuit 5 is equipped with an excitation winding (not shown).

An elastic sealing ring 7 is fixed on the emitting end 10 of the waveguide 3 in the area of ​​the displacement unit. In this case, the lower end of the magnetic circuit 5 of the annular radiator 6 is located in the same plane with the radiating end 10 of the acoustic waveguide 3. Moreover, the surface of the radiating end 10 of the acoustic waveguide 3 is made concave, spherical, with a sphere radius equal to half the length of the magnetic circuit 5 of the annular magnetostrictive radiator 6.

As a rod ultrasonic transducer, for example, an ultrasonic magnetostrictive transducer of the PMS-15A-18 type (BT3.836.001 TU) or PMS-15-22 9SYUIT.671.119.003 TU) can be used. If the technological process requires higher frequencies: 44 kHz, 66 kHz, etc., then the rod transducer is based on piezoceramics.

The magnetic circuit 5 can be made of a material with negative striction, for example, nickel.

The ultrasonic installation works as follows. Supply voltages are applied to the excitation windings of the converter 1 and the annular magnetostrictive emitter 6. The working chamber 4 is filled with the liquid medium 12 to be treated, for example, to perform dissolution, emulsification, dispersion, or it is filled with a liquid medium into which parts are placed for cleaning surfaces. After the supply voltage is applied in the working chamber 4, an acoustic field with two resonant frequencies is formed in the liquid medium 12.

Under the influence of the generated two-frequency acoustic field in the treated medium 12, acoustic flows and cavitation arise. In this case, as shown above, cavitation bubbles differ in size: larger ones are the result of exposure to a liquid medium of low frequency, and small ones - of high frequency.

In a cavitating liquid medium, for example, when dispersing or cleaning surfaces, small bubbles penetrate into cracks and cavities of the solid component of the mixture and, collapsing, form micro-shock effects, weakening the integrity of the solid particle from the inside. Bubbles of a larger size, collapsing, break the particle weakened from the inside into small fractions.

In addition, as a result of the interaction of acoustic waves with different resonance frequencies, beatings occur, leading to a sharp instantaneous increase in the amplitude of the acoustic pressure (to an acoustic shock), which leads to an even more intensive destruction of layers on the surface to be cleaned and to an even greater crushing of solid fractions in the treated liquid. medium when receiving a suspension. At the same time, the presence of two resonant frequencies enhances the turbulence of acoustic flows, which contributes to more intensive mixing of the processed liquid medium and more intensive destruction of solid particles both on the surface of the part and in suspension.

During emulsification and dissolution, large cavitation bubbles destroy intermolecular bonds in the components of the future mixture, shortening the chains, and form conditions for small cavitation bubbles for further destruction of intermolecular bonds. An acoustic shock wave and increased turbulence of acoustic flows, which are the results of two-frequency sounding of the treated liquid medium, also destroy intermolecular bonds and intensify the process of mixing the medium.

As a result of the combined effect of the above factors on the processed liquid medium, the performed technological process is intensified without reducing the quality of the final product. As tests have shown, in comparison with the prototype, the specific power of the claimed converter is twice as high.

To enhance the cavitation effect in the installation, an increased static pressure can be provided, which can be implemented similarly to the prototype (A.V. Donskoy, OKKeller, G.S.Kratysh "Ultrasonic Electrotechnological Installations", Leningrad: Energoizdat, 1982, p. 169) : a system of pipelines connected with the internal volume of the working chamber; compressed air cylinder; safety valve and pressure gauge. In this case, the working chamber must be equipped with a sealed cover.

1. An ultrasonic installation containing a rod ultrasonic transducer, a working chamber made in the form of a metal cylindrical pipe, and an acoustic waveguide, the emitting end of which is hermetically connected to the bottom of the cylindrical pipe by means of an elastic sealing ring, and the receiving end of this waveguide is acoustically rigidly connected to the emitting surface rod ultrasonic transducer, characterized in that an annular magnetostrictive emitter is additionally introduced into the installation, the magnetic circuit of which is acoustically rigidly pressed onto the tube of the working chamber.

2. Installation according to claim 1, characterized in that the elastic sealing ring is fixed at the radiating end of the waveguide in the area of ​​the displacement unit.

3. Installation according to claim 2, characterized in that the lower end of the magnetic circuit of the annular radiator is located in the same plane with the radiating end of the acoustic waveguide.

4. Installation according to claim 3, characterized in that the surface of the radiating end of the acoustic waveguide is made concave, spherical, with a sphere radius equal to half the length of the magnetic circuit of the annular magnetostrictive emitter.

The installation consists of a laboratory rack, an ultrasonic generator, a high-efficiency, high-Q magnetostrictive transducer and three waveguide-emitters (concentrators) to the transducer. has a stepwise regulation of output power, 50%, 75%, 100% of the rated output power. Power control and the presence in the set of three different waveguide-emitters (with a gain of 1: 0.5, 1: 1 and 1: 2) allows you to obtain different amplitudes of ultrasonic vibrations in the studied liquids and elastic media, approximately, from 0 to 80 microns at a frequency of 22 kHz.

Years of experience in manufacturing and sales ultrasonic equipment confirms the perceived need to equip all types of modern high-tech production with Laboratory facilities.

The production of nano-materials and nano-structures, the introduction and development of nano-technologies is impossible without the use of ultrasonic equipment.

With the help of this ultrasonic equipment it is possible:

• obtaining nano-powders of metals;
• use when working with fullerenes;
• investigation of the course of nuclear reactions in conditions of strong ultrasonic fields (cold fusion);
• excitation of sonoluminescence in liquids, for research and industrial purposes;
• creation of finely dispersed normalized direct and reverse emulsions;
• wood sounding;
• excitation of ultrasonic vibrations in metal melts for degassing;
• and many many others.

Modern ultrasonic dispersers with digital generators I10-840 series

Ultrasonic installation (disperser, homogenizer, emulsifier) ​​I100-840 is designed for laboratory studies of the effect of ultrasound on liquid media with digital control, with smooth adjustment, with digital selection of the operating frequency, with a timer, with the ability to connect oscillatory systems of different frequency and power and recording processing parameters into non-volatile memory.

The installation can be completed with ultrasonic magnetostrictive or piezo-thermal vibration systems with an operating frequency of 22 and 44 kHz.

If necessary, it is possible to equip the dispersant with oscillating systems for 18, 30, 88 kHz.

Ultrasonic laboratory installations (dispersants) are used:

• for laboratory studies of the effect ultrasonic cavitation on various liquids and samples placed in liquid;
• to dissolve difficult or little soluble substances and liquids in other liquids;
• for testing various liquids for cavitation strength. For example, to determine the stability of the viscosity of industrial oils (see GOST 6794-75 for AMG-10 oil);
• to study changes in the rate of impregnation of fibrous materials under the influence of ultrasound and to improve the impregnation of fibrous materials with various fillers;
• to exclude aggregation of mineral particles during hydro sorting (abrasive powders, geomodifiers, natural and artificial diamonds, etc.);
• for ultrasonic cleaning of complex products of automotive fuel equipment, nozzles and carburetors;
• for research on the cavitation strength of machine parts and mechanisms;
• and in the simplest case - as a highly intense ultrasonic washing bath. Sediments and deposits on glassware and glass are removed or dissolved in seconds.