RU2822084C1 - Ultrasonic oscillating system for gaseous media - Google Patents

Abstract

FIELD: acoustics.

SUBSTANCE: ultrasonic oscillating system for gaseous media consists of series-arranged and acoustically connected to each other longitudinally oscillating piezoelectric transducer and an ultrasonic oscillation emitter into a gas medium in the form of a disc made of metal, the geometric dimensions of which are selected from the condition for the formation of bending vibrations at operating frequency corresponding to natural resonance frequency of piezoelectric transducer and multiple of fundamental frequency of disk radiator, on the side of the disc radiator surface, opposite to the connection with the piezoelectric transducer, at a distance of less than a quarter of the wavelength of ultrasonic oscillations in a gas medium at the fundamental frequency of the ultrasound oscillations formed by the piezoelectric transducer, horns are placed, made in the form of annular diverging truncated cones, with an opening angle of 90 degrees, on the side of the disc radiator connection with the piezoelectric transducer, an ultrasonic oscillation reflector is placed, made in the form of two concentrically located truncated cones with an opening angle of 90 degrees, cones are connected to each other and attached to the piezoelectric transducer housing at the connection point.

EFFECT: creation of ultrasonic vibrations of high intensity in gaseous media.

1 cl, 3 dwg

Description

The invention relates to the field of technology for the influence of ultrasonic vibrations (US) on gaseous media and objects in gaseous media, namely to devices for producing mechanical vibrations of ultrasonic frequency, designed to intensify the processes of cleaning gas emissions of harmful substances from industrial enterprises, capturing products obtained in a finely dispersed state for return to the production cycle, low-temperature removal of moisture from thermolabile, flammable and explosive materials, defoaming and implementation of similar processes in gaseous media, as well as for long-distance transmission of information in the ultrasonic (inaudible by humans) frequency range, use in control and security alarm systems.

The requirements of modern industries to increase efficiency, reduce energy intensity, and increase the speed of various technological processes in gaseous environments necessitate the search for new effective ways to intensify them.

One of the promising ways to intensify processes is the use of ultrasonic frequency oscillations with a high level of sound pressure (up to 150...170 dB) [1].

The effectiveness of high-intensity ultrasonic vibrations on various technological processes in gaseous media has been confirmed by numerous studies [2-5], which made it possible to establish the following:

1. The use of ultrasonic vibrations with a sound pressure level of more than 150 dB (high intensity) for the purification of industrial waste gases (in particular, for trapping and sedimentation of the finished product) makes it possible to increase the efficiency of dust collection units and increase its value to 93-97% without the use of electrostatic or bag filters.

2. The use of ultrasonic vibrations with a sound pressure level of more than 150 dB (high intensity) is effective for the deposition of aerosols of natural origin and aerosol pollution of the atmosphere, for the deposition of man-made aerosols formed during explosions, as well as for dispersing fogs over airport runways and water areas sea and river ports, over highways.

3. High efficiency of moisture removal without increasing the temperature during drying in an ultrasonic field allows you to improve the quality of the final product, increase the speed of the process and reduce energy consumption. In addition, exposure to ultrasonic vibrations with a high sound pressure level (more than 130...150 dB) has a beneficial effect on the physicochemical and consumer properties of the dried product (preserves the taste of the product, increases the shelf life and germination of seeds, etc.).

4. The use of ultrasonic vibrations with a high sound pressure level (more than 150...160 dB) for defoaming eliminates the use of chemical reagents, as well as contact with destructible foam, which ensures the sterility of the final product. In addition, the use of ultrasonic vibrations with a high level of sound pressure in the wave to extinguish foams of flammable liquids is sometimes the only possible way to eliminate them.

5. The use of ultrasonic vibrations with a high sound pressure level (more than 150 dB) ensures the highest possible efficiency (minimum energy consumption) and confidentiality (frequency range not audible to the human ear) of information transmission over long distances (more than 100...1000 m) without the use of special receiving devices (detection is carried out due to the properties of the medium - air) and communication channels.

In all cases, the implementation of processes is ensured by the use of sources of ultrasonic influence - ultrasonic oscillatory systems for gaseous media. When creating such systems, a number of complex problems are solved due to the fact that gaseous media have a low acoustic impedance and a high ultrasound absorption coefficient. To ensure effective radiation of ultrasonic vibrations (transfer of energy) into gaseous media, it is necessary that the impedances (wave impedances) of the emitter and the gaseous environment are maximally matched, and for this it is necessary to achieve the maximum level of pressure drop in the ultrasonic wave, i.e. the highest amplitude of oscillations of the emitter and narrow radiation direction (directional pattern).

Piezoelectric ultrasonic oscillatory systems are the most widely used for intensifying processes in various technological environments. However, the ultrasonic influence with a sound pressure level of more than 150 dB, necessary for carrying out processes in gaseous media, cannot be provided by classical piezoelectric ultrasonic oscillatory systems. This limits the possibilities of industrial application of ultrasound in gaseous media and necessitates the creation of new devices based on a more effective principle of creating high-intensity ultrasonic vibrations.

Among the well-known piezoelectric ultrasonic oscillatory systems [6-10], designed to intensify technological processes in gaseous media, the one closest to the proposed one in design and technical essence is the ultrasonic oscillatory system according to the patent [11], adopted as a prototype.

An ultrasonic oscillatory system for gaseous media, adopted as a prototype, consists of a sequentially located and acoustically interconnected longitudinally oscillating piezoelectric transducer and an emitter of ultrasonic vibrations into a gaseous environment in the form of a disk made of metal, the geometric dimensions of which are selected from the condition of the formation of bending vibrations at the working stage. frequency corresponding to the natural resonant frequency of the piezoelectric transducer and a multiple of the fundamental frequency of the disk emitter.

To effectively generate ultrasonic vibrations in gaseous media, the emitter is made in the form of a metal disk capable of performing bending vibrations at frequencies that are multiples of the fundamental frequency of the emitter. The choice of titanium alloys as the metal used ensures maximum structural strength. The piezoelectric transducer is made according to the well-known Langevin transducer circuit and consists of sequentially placed and acoustically connected reflective frequency-reducing pads of a cylindrical shape, piezoelectric elements and a working frequency-reducing pad, which can be made with a variable diameter (concentrator) to provide amplification of ultrasonic vibrations created by the piezoelements . The piezoelectric transducer performs longitudinal vibrations at a resonant frequency determined by the longitudinal size (length) of the entire structure. Longitudinal vibrations arriving at the emitter are converted into bending vibrations, which are emitted into the gaseous environment. The main disadvantages of the prototype are as follows: 1. The known ultrasonic oscillating system is practically unsuitable for technological purposes, since it is not capable of providing high efficiency of ultrasonic influence. This is due to the fact that during bending vibrations of a disk of constant cross-section, neighboring sections vibrate in antiphase, i.e. the central zone of a disk emitter of a certain diameter (determined by the thickness and properties of the metal) oscillates with a phase coinciding with the oscillation phase of the transducer, the next annular zone of the disk emitter oscillates with the opposite phase at the fundamental frequency of the transducer, and each subsequent odd annular zone oscillates with the phase corresponding to the transducer, and each subsequent even-numbered ring zone oscillates with the phase opposite to the converter.

Due to this property of the flexural-oscillating emitter, the radiation of neighboring zones that create oscillations with opposite phases is compensated at a certain distance from the emitter and cannot provide the required ultrasonic effect on the objects being processed.

In practice, this leads to the impossibility of forming ultrasonic vibrations with a sound pressure level of more than 130 dB even at a distance of 1 m from the emitter;

2. The known ultrasonic oscillatory system is practically unsuitable for transmitting vibrations over significant distances, since it ensures the formation of a very wide directional pattern (characteristics). This happens because the radiation from neighboring zones occurs with opposite phases and is compensated at a certain distance from the emitter. Therefore, the known ultrasonic oscillatory system is characterized by a very wide radiation pattern (more than 15...30 degrees) and a large number of generated side lobes of the radiation pattern (formed by the radiation of ring zones oscillating with different phases).

3. When trying to increase the amplitude of oscillations of the emitter by increasing the amplitude of oscillations of the transducer to generate ultrasonic oscillations with a sound pressure level of more than 130 dB, the metal is destroyed in places of maximum mechanical stress (between zones oscillating in antiphase), which leads to failure of the emitter .

Thus, the device adopted as a prototype does not allow the formation of ultrasonic vibrations with a sound pressure level of more than 130 dB, ensuring their propagation over long distances to intensify technological processes in gaseous environments with the maximum possible efficiency, in the maximum possible volumes and at the maximum possible distances from emitter.

In the proposed ultrasonic oscillatory system for gaseous media, consisting of a sequentially located and acoustically interconnected longitudinally oscillating piezoelectric transducer and an emitter of ultrasonic vibrations into a gaseous environment in the form of a disk made of metal, the geometric dimensions of which are selected from the condition of the formation of bending vibrations at the operating frequency, corresponding to the natural resonant frequency of the piezoelectric transducer and a multiple of the fundamental frequency of the disk emitter, on the side of the surface of the disk emitter opposite to the connection with the piezoelectric transducer, at a distance of less than a quarter of the wavelength of ultrasonic oscillations in a gaseous medium, at the main frequency of the ultrasonic oscillations generated by the piezoelectric transducer, horns are placed, made in the form of annular diverging truncated cones, with an opening angle of 90 degrees, and the diameter of the smaller base of the central cone and each subsequent odd cone corresponds to the diameter of the surface of the disk emitter, oscillating with a phase coinciding with the oscillation phase of the transducer and increases to a diameter corresponding to the maximum diameter of the annular zone of the disk emitter, oscillating with the opposite phase at the fundamental frequency of the converter, following the central one and each subsequent even annular divergent truncated cone located above the zone oscillating with the phase opposite to the converter has a diameter of a smaller base at the surface of the disk emitter, corresponding to the diameter of the zone of the disk emitter oscillating with the opposite phase at the main frequency of the transducer, increased by half the wavelength of ultrasonic oscillations in a gaseous medium and increases to a diameter corresponding to the maximum diameter of the next annular zone of the surface of the disk emitter, oscillating with a phase opposite to the phase of the transducer, on the side of the connection of the disk emitter with the piezoelectric transducer, at a distance of less than a quarter of the wavelength Ultrasonic vibrations in a gas environment contain a reflector of ultrasonic vibrations, made in the form of two concentrically located truncated cones with an opening angle of 90 degrees; the cones are interconnected and attached at the junction to the piezoelectric transducer body.

In the proposed device, the task of increasing the efficiency of an ultrasonic oscillatory system intended for the implementation of technological processes in gaseous media is achieved through:

- using a disk that performs flexural oscillations as a radiator (providing the highest possible energy output of ultrasonic oscillations, since the wave impedance of a flexural-oscillating emitter is better than a longitudinally oscillating one, consistent with the wave impedance of the gaseous medium), placing horns in front of the radiating surfaces, made and located in such a way in such a way that oscillations with the same phase are formed at the output of them. Thus, the radiation of the flexural-oscillating emitter is actually converted into the radiation of a longitudinally oscillating emitter, which forms a plane wave with a constant phase, and the diameter of the emitting surface, due to the use of oscillations on the side of the connection with the converter, doubles.

Thus, by ensuring the uniformity of radiation of ultrasonic vibrations over the newly formed radiation surface (at a certain distance from the disk metal emitter, equal to the height of the cone horns), mutual compensation of vibrations at certain distances from the emitter is eliminated, and it is possible to form standing wave modes and resonant amplification at the use of counter-directed emitters or reflection from obstacles, since the vibrations created by the proposed device are sinusoidal.

The essence of the proposed technical solution is illustrated in Figs. 1-3. Figure 1 shows a design diagram of a known ultrasonic oscillatory system for intensifying processes in gaseous media (coagulation, drying, defoaming, atomization) to explain the principles of the formation of ultrasonic vibrations by a bending-oscillating emitter and the directional pattern of emitted vibrations generated by such a system. Figure 2 shows a sketch of the proposed ultrasonic oscillatory system with a disk-shaped emitter and horn devices that ensure the emission of ultrasonic oscillations into the space in front of the emitter with one phase, as well as the directional pattern of the emitted oscillations formed by such a system. Figure 3 shows the practical design of the proposed ultrasonic oscillating system for gas media with a bending-oscillating emitter and a system of phase-equalizing cone horns.

The known ultrasonic oscillatory system (Fig. 1) for gaseous media consists of a sequentially located and acoustically interconnected longitudinally oscillating piezoelectric transducer 1 and an emitter 2 of ultrasonic vibrations into a gaseous environment in the form of a disk made of metal, the geometric dimensions of which are selected from the condition of the formation of bending vibrations at the operating frequency corresponding to the natural resonant frequency of the piezoelectric transducer 1 and a multiple of the fundamental frequency of the disk emitter 2.

As an example, we consider a disk emitter that performs bending oscillations on the mode (third) of the main oscillations, which has two zones (central 3 and outer 4), oscillating with a phase corresponding to the oscillation phase of the piezoelectric transducer 1 and an annular zone 5 located between them, oscillating with phase opposite to the oscillation phase of piezoelectric transducer 1.

During bending vibrations of a disk of constant cross-section, annular zones 3 and 4 oscillate in phase, and annular zone 5 oscillates in antiphase, i.e. the central zone of a disk emitter of a certain diameter (determined by the thickness and properties of the metal) oscillates with a phase coinciding with the oscillation phase of the transducer, the next annular zone of the disk emitter oscillates with the opposite phase at the fundamental frequency of the transducer, and each subsequent even annular zone oscillates with the phase opposite to the transducer, and each subsequent odd annular zone oscillates with the phase corresponding to the converter. This is conventionally illustrated in Fig. 1 by the shown propagating sinusoidal oscillations 6 with different initial phases.

Thanks to this property of the flexural-oscillating emitter, the radiation of neighboring zones having opposite phases is compensated at some distance from the emitter, forming a wide radiation pattern 7 (about 30 degrees), shown in Fig. 1. For this reason, the known oscillatory system does not provide the required propagation in space and ultrasonic influence on the objects being processed.

The proposed ultrasonic oscillatory system for gaseous media (Fig. 2) also consists of a sequentially located and acoustically interconnected longitudinally oscillating piezoelectric transducer 1 and an emitter 2 of ultrasonic vibrations into a gaseous environment in the form of a disk made of metal, the geometric dimensions of which are selected from the condition of the formation of bending oscillations at an operating frequency corresponding to the natural resonant frequency of the piezoelectric transducer 1 and a multiple of the fundamental frequency of the disk emitter 2.

As an example of the proposed system, we also consider a disk radiator that performs bending vibrations at the third mode of fundamental vibrations, i.e. as well as the known device, which has two zones (central 3 and outer 4) oscillating with a phase corresponding to the oscillation phase of the piezoelectric transducer 1 and an annular zone 5 located between them, oscillating with a phase opposite to the oscillation phase of the piezoelectric transducer 1.

In the proposed device, during bending vibrations of a disk of constant cross-section, as in the known device, adjacent zones 3 and 4 oscillate in phase, and the annular zone 5 oscillates in antiphase, i.e. the central zone of a disk emitter of a certain diameter (determined by the thickness and properties of the metal) oscillates with a phase coinciding with the oscillation phase of the transducer, the next annular zone of the disk emitter oscillates with the opposite phase at the fundamental frequency of the transducer, and each subsequent even annular zone oscillates with the phase opposite to the transducer, and each subsequent odd annular zone oscillates with the phase corresponding to the converter.

However, in the proposed device, on the side of the surface of the disk emitter 2, opposite to the connection with the piezoelectric transducer 1, at a distance of less than a quarter of the wavelength of ultrasonic oscillations in a gaseous environment, at the main frequency of the ultrasonic oscillations generated by the piezoelectric transducer, horns 8, 9 and 10 are placed, made in the form ring diverging truncated cones, with an opening angle of 90 degrees, and the diameter of the smaller base of the central cone 8 and each subsequent odd cone 9 corresponds to the diameter of the surface of the disk emitter, oscillating with a phase coinciding with the oscillation phase of the transducer and increases to a diameter corresponding to the maximum diameter of the annular zone of the disk emitter oscillating with the opposite phase at the fundamental frequency of the converter. Next to the central one 8 and each subsequent even annular divergent truncated cone 9 located above the zone oscillating with the phase opposite to the converter has a diameter of a smaller base at the surface of the disk emitter corresponding to the diameter of the zone of the disk emitter oscillating with the opposite phase at the fundamental frequency of the converter, increased by half the wavelength of ultrasonic oscillations in a gaseous medium (i.e. equal to the height of cone 1, increased by half the wavelength a/2) and increases to a diameter corresponding to the maximum diameter of the next annular zone of the surface of the disk emitter, oscillating with a phase opposite to the phase of the transducer. On the side of the connection of the disk emitter with the piezoelectric transducer, at a distance of less than a quarter of the wavelength of ultrasonic vibrations in a gaseous medium, an ultrasonic vibration reflector is placed, made in the form of two concentrically located truncated cones 11 and 12 with an opening angle of 90 degrees, the cones are connected to each other and attached to the connection point to the piezoelectric transducer body.

Placing horns in the proposed device in front of the radiating surfaces of a bending-oscillating metal disk, made and located in such a way that oscillations with the same phase are formed at the output of them, ensures the formation of a plane wave with a constant phase, and the diameter of the emitting surface, due to the use of oscillations from the side connection to the converter is doubled.

Thus, by ensuring the uniformity of radiation of ultrasonic vibrations over the newly formed radiation surface, mutual compensation of vibrations at certain distances from the emitter is eliminated. At a distance of 1 m from the emitter, the formation of ultrasonic oscillations with a sound pressure level of at least 150 dB and a radiation pattern of less than 5 degrees 7 is ensured, even when using an emitter oscillating at the 3rd vibration mode (100 mm in diameter). When using disk emitters with a diameter of more than 300 mm, performing ultrasonic vibrations at modes 5...7 of vibration, radiation with a sound pressure level of at least 165...170 dB is ensured.

The proposed device, when intensifying processes in gaseous media, operates as follows: the generator is turned on, electrical oscillations, the frequency of which corresponds to a given harmonic component (maximum frequency) of oscillations of the disk emitter, are fed to the electrodes of the piezoelectric elements, where the electrical oscillations of the supplied frequency are converted by all piezoelements into longitudinal oscillations converter, longitudinal vibrations are supplied to the emitter and excite it at a resonant frequency corresponding to one of the modes or harmonic components of the fundamental frequency of bending vibrations of the emitter in the form of a disk.

The generated radiation provides energetic exposure to ultrasonic vibrations with a sound pressure level of more than 150 dB at a given frequency in gaseous media. The impact is carried out until the necessary technological conditions are established (enlargement of particles to the required size, the required degree of moisture removal during drying, maintaining the required level of foam, as well as for transmitting information over the required distances).

To determine the effectiveness of exposure to high-intensity ultrasonic vibrations in gaseous media, a prototype was created (Fig. 3) and tests were carried out, which made it possible to establish that the level of sound pressure of vibrations generated using an ultrasonic oscillatory system with a radiator in the form of a disk or rectangular plate, at a distance 1 m was at least 150 dB. The given values show the effectiveness of the proposed technical solution and the prospects for its application. Serial production of this device is planned for 2024.

List of literature used in drawing up the application

1. Sources of powerful ultrasound [Text] / ed. L.D. Rosenberg. - M.: Nauka, 1967. - 265 p.

2. Ultrasonic coagulation chamber for work in aggressive environments [Text] / V.N. Khmelev, A.V. Shalunov, K.V. Shalunova. Collection of scientific papers “Modern problems of radio electronics” / Ed. A.I. Gromyko, A.V. Sarafanova. - Krasnoyarsk: IFC SFU, 2009. - P. 232-235.

3. Ultrasonic coagulation on the basis of piezoelectric vibrating system with focusing radiator in the form of step - variable plate [Text] / Khmelev V.N., Galakhov A.N., Tsyganok S.N., Lebedev A.N., Shalunov A.V., Khmelev M.V. 11th Annual International Conference and Seminar on Micro/Nanotechnologies and Electron, EDM'2010 - Proceedings: Altai 2010. pp. 376-379.

4. Development of piezoelectric ultrasonic oscillatory systems for intensification of processes in gaseous media [Text] / Khmelev V.N., Tsyganok S.N., Shalunov A.V., Lebedev A.N., Khmelev S.S., Galakhov A. N. News of Tula State University. Technical science. 2010. No. 1. pp. 148-157.

5. Method of coagulation of foreign particles in gas flows [Text] pat.2447926 Ross. Federation: IPC B01D 51/08, B03D 3/04 / Khmelev V.N., Shalunov A.V., Tsyganok S.N., Barsukov R.V., Shalunova K.V., Galakhov A.N.; patent holder: State educational institution of higher professional education “Altai State Technical University named after. I.I. Polzunov" (AltSTU); application No. 2010123572/05 dated 06/09/2010; published 04/20/2012.

6. Acoustic transducer system [Text]: Pat. 4768615 USA: MPK7 G10K 11/26; G10K 13/00; H04R 1/28; H04R 1/34; G10K 11/00; G10K 13/00; H04R 1/28; H04R 1/32 / Steinebrunner Edwin, Berger Wolfram (Germany); Patent holder: Endress u. Hauser GmbH u. Co. (Germany); application: No. 07/007102 dated January 27, 1987; published: 09/06/1988.

7. Electroacoustic unit for generating high sonic and ultra-sonic intensities in gases and interphases [Text]: patent. 5299175 USA: IPC7 B06B 1/02; B06B 3/04; G10K 13/00 / Gallego Juarez Juan Antonio., Rodriguez Corral German., San Emetero Prieto Jose L., Montoya Vitini Fausto (Spain); Patentee: Consejo, Superior De Investigaciones Cientificas (Spain); application No. 08/006040 dated January 19, 1993; published: 03/29/1994.

8. Macrosonic generator for the air-based industrial defoaming of liquids [Text]: patent. 7719924 B2 USA: IPC H04R 17/00; В06В 1/02; G10K 9/12; G10K 11/02; H04R 15/00 / Gallego Juarez Juan Antonio., Rodriguez Corral German., Montoya Vitini Fausto., Acosta Aparicio Victor., Riera Franco De Sarabia Enrique., Blanco Blanco Alfonso (Spain); patent holder: Insituto de Acustica (Spain); application No. 11/989544 dated July 27, 2005, published May 18, 2010.

9. Ultrasonic emitter for gaseous media [Text]: patent. 117835 Ross. Federation: MPK B06V 1/06 / Vyuginova A.A., Novik A.A.; Patent holder: Closed Joint Stock Company "Ultrasonic Technology - INLAB"; application No. 2012114036/28 dated 04/10/2012; published 07/10/2012.

10. Equipo electroacustico para la generacion de altas intensidades sonicas y ultrasonicasen gases e interfases [Text]: Pat. 2017285 Spain: MPK6 G10K 9/13 / Gallego Juarez J.A., Rodrguez Corral G., San Emeterio Prieto J.L., Montoya Vitini, F. (Spain); patent holder: Consejo superior investigacion (Spain); application: No. 8903371 dated 10/06/1989; published: 01/16/1991.

11. Ultrasonic oscillatory system for gaseous media [Text]: Utility model patent No. 132000. Ross. Federation: IPC B06B 1/00/ Khmelev V.N., Galakhov A.N., Shalunov A.V., Nesterov V.A.; Patent holder: LLC “Center for Ultrasonic Technologies of Altai State Technical University”; application No. 2013123940/28 dated May 24, 2013; published 09.10.2013 Bulletin. No. 25 - prototype.

Claims (1)

An ultrasonic oscillatory system for gaseous media, consisting of a sequentially located and acoustically interconnected longitudinally oscillating piezoelectric transducer and an emitter of ultrasonic vibrations into a gaseous environment in the form of a disk made of metal, the geometric dimensions of which are selected from the condition of the formation of bending vibrations at the operating frequency corresponding to the natural frequency resonant frequency of the piezoelectric transducer and a multiple of the fundamental frequency of the disk emitter, characterized in that on the side of the surface of the disk emitter opposite the connection with the piezoelectric transducer, at a distance of less than a quarter of the wavelength of ultrasonic oscillations in a gaseous medium at the fundamental frequency of the ultrasonic oscillations generated by the piezoelectric transducer, horns are placed, made in in the form of annular diverging truncated cones, with an opening angle of 90 degrees, and the diameter of the smaller base of the central cone and each subsequent odd cone corresponds to the diameter of the surface of the disk emitter, oscillating with a phase coinciding with the oscillation phase of the transducer, and increases to a diameter corresponding to the maximum diameter of the annular zone of the disk emitter oscillating with the opposite phase at the fundamental frequency of the transducer, following the central one and each subsequent even annular divergent truncated cone located above the zone oscillating with the phase opposite to the transducer, has a diameter of a smaller base at the surface of the disk emitter, corresponding to the diameter of the zone of the disk emitter oscillating with opposite phase at the fundamental frequency of the transducer, increased by half the wavelength of ultrasonic oscillations in a gaseous medium, and increases to a diameter corresponding to the maximum diameter of the next annular zone of the surface of the disk emitter, oscillating with a phase opposite to the phase of the transducer, on the side of the connection of the disk emitter with the piezoelectric transducer, on At a distance of less than a quarter of the wavelength of ultrasonic vibrations in a gaseous medium, an ultrasonic vibration reflector is placed, made in the form of two concentrically located truncated cones with an opening angle of 90 degrees; the cones are interconnected and attached at the junction to the piezoelectric transducer body.