LT7159B - ULTRASONIC ACOUSTIC AGGLOMERATION CHAMBER FOR SOLID PARTICLES - Google Patents

Abstract

The ultrasonic acoustic agglomeration chamber consists of a cylindrical body (1), three ultrasonic acoustic pressure sources (2) formed from Langevin-type transducers (17) and concentrators (11), at the free ends of which are attached disk-shaped acoustic radiators (10), the mechanical bending vibrations of which create an overlapping acoustic, standing wave field, and the resonant frequency of the first bending mode of the radiators coincides with the resonant frequency of the longitudinal vibration mode. The acoustic sources (2) are attached to the body of the chamber (1) using fastening parts (3, 4) and clamping discs (5), ensuring that the free surfaces of the acoustic radiators (10) are tangent to the inner diameter of the body (15). The angular distance (16) of the acoustic pressure sources (2) with respect to the longitudinal axis of the chamber body (1) is selected so that the acoustic pressure sources (2) are evenly distributed along the perimeter of the chamber body, and the inner diameter (15) of the chamber is selected so that its ratio to the wavelength of the acoustic field is an integer.

Description

FIELD OF THE INVENTION

The invention belongs to the fields of air purification, industrial filtration and energy saving technologies. The design is intended to create acoustic agglomeration chambers for fine and ultra-fine solid particles with zero resistance to air flow and can be applied in the development of combined air filtration systems and devices, the application of which is aimed at increasing the filtration efficiency of fine and ultra-fine solid particles.

STATE OF THE ART

Traditional particulate matter filtration solutions do not always work effectively when fine and ultrafine micrometric or nanometric sized particulate matter is encountered in the filtered air stream. In order to solve this problem, acoustic agglomeration of particulate matter is applied. Acoustic agglomeration, as a primary treatment of filtered air, is applied in various industries to improve the efficiency of traditional air filtration solutions by trapping fine particulate matter by exposing them to high frequency and intensity acoustic fields. One of the research directions is the development of high frequency and high acoustic intensity acoustic agglomeration chambers, in which the generated acoustic wavelengths, acoustic pressures and their distributions in the chamber ensure the appropriate acoustic field effect on fine and ultrafine particulate matter, thus creating conditions for the agglomeration of these particles into larger sized agglomerates, which consequently improves the efficiency of traditional particulate matter filtration solutions in filtering and trapping fine particulate matter. Also, by changing the acoustic wavelengths of the acoustic fields created in the agglomeration chamber or the intensity of the acoustic pressure, the operation of the agglomeration chamber can be adjusted, taking into account the sizes of the particles dominating the air flow, ensuring conditions for more efficient formation of agglomerates of fine and ultra-fine particles.

Patent CN204619662U describes a rectangular acoustic agglomeration chamber, on opposite sides of which, through telescopic cone-shaped diffusers, six electromagnetic acoustic pressure sources are placed, which are synchronously excited by an electrical signal whose frequency can be changed from 1500 Hz to 2000 Hz, while the distance between the opposite electromagnetic acoustic pressure sources can be changed through telescopic cone-shaped diffusers. In addition, a passive particulate filter is placed at the outlet of the acoustic agglomeration chamber, while the internal free surfaces of the chamber are covered with a sound-absorbing material. The operation of the acoustic agglomeration chamber is based on three acoustic fields that are created by exciting the six electromagnetic acoustic pressure sources. Ambient air is drawn in through the chamber's intake opening and the solid particles in it are affected by these acoustic fields, which creates an agglomeration effect of solid particles, which results in the formation of agglomerates of solid particles that are retained in the chamber's outlet opening in the passive air filter, thus increasing the efficiency of this filter in retaining fine and ultra-fine solid particles.

Patent US5769913A describes an acoustic agglomeration chamber consisting of a rectangular duct on one of the surfaces of which is placed an isosceles triangular acoustic wave reflection structure, in the center of which, perpendicular to the axis of symmetry of the reflection structure, is mounted an ultrasonic acoustic pressure source consisting of an ultrasonic transducer and a stepped, disk-shaped, acoustic pressure emitter. The operation of the acoustic ultrasonic agglomeration chamber is based on the reflection of the acoustic field created by the ultrasonic acoustic pressure source, through the triangular reflection structure, into the rectangular duct. The use of a triangular acoustic field reflection structure in the agglomeration chamber ensures a longer and more uniform impact of the acoustic field on the air flow that is drawn through the intake opening of the rectangular duct, as a result of which an increased impact is obtained on the solid particles present in the drawn air flow, thus ensuring more efficient formation of solid particle agglomerates.

Patent CN118403455A describes an ultrasonic multi-frequency multi-stage acoustic agglomeration chamber for solid particles, which consists of two or more stages in which acoustic fields of different frequencies and intensities are created using ultrasonic piezoelectric acoustic field sources of different operating frequencies, which consist of piezoelectric Lajevin-type transducers and disk-shaped acoustic pressure radiators, while acoustic wave reflectors are placed on the opposite side of the chamber, thus ensuring uniform distribution of the created acoustic fields in the stages of the agglomeration chamber. The operation of the agglomeration chamber is based on the stepwise exposure of solid particles contained in the air drawn into the chamber to acoustic fields of different frequencies and intensities, which are created in separate stages of the chamber using different ultrasonic piezoelectric acoustic pressure sources, thus creating conditions for the formation of solid particle agglomerates with different acoustic characteristics and thus ensuring secondary or tertiary growth of solid particle agglomerates.

THE ESSENCE OF THE INVENTION

The aim of the invention is to improve the acoustic field characteristics of an ultrasonic agglomeration chamber and the acoustic pressure distribution in the chamber.

The purpose of the invention is achieved by the fact that the ultrasonic agglomeration chamber consists of a cylindrical body, three ultrasonic piezoelectric Langevin-type transducers, at the ends of which disk-shaped acoustic pressure emitters are permanently attached, thus forming ultrasonic acoustic pressure sources that are synchronously excited by a single harmonic electrical signal.

In order to improve the acoustic pressure characteristics of the ultrasonic agglomeration chamber, the geometric characteristics of the disk-shaped acoustic radiators and piezoelectric Langevin-type transducers are mutually coordinated so that the resonant frequency of the first longitudinal vibration mode of the Langevin-type transducers coincides with the resonant frequency of the first bending vibration mode of the disk-shaped acoustic radiator mounted on it.

In order to improve the acoustic pressure distribution in the agglomeration chamber volume and the acoustic characteristics of the chamber, ultrasonic acoustic pressure sources are arranged at equal intervals around the outside of the cylindrical housing. This arrangement ensures a uniform distribution of acoustic pressure throughout the chamber volume and improves its acoustic characteristics due to the overlap of the three acoustic fields.

DESCRIPTION OF DRAWINGS

The figures of the drawings are provided as a reference to possible embodiments of the invention and are not intended to limit the scope of the invention. None of the figures provided should be considered limiting, but only as possible examples of embodiments of the invention.

Fig. 1 a,b Ultrasonic particle acoustic agglomeration chamber:

- isometric view of an ultrasonic particle acoustic agglomeration chamber;

(b) - exploded view of the ultrasonic particle acoustic agglomeration chamber;

Fig. 2 a, b Ultrasonic acoustic pressure source:

- isometric view of an ultrasonic acoustic pressure source;

(b) - exploded view of the ultrasonic acoustic pressure source;

Fig. 3 Excitation scheme of ultrasonic acoustic pressure sources;

DRAWINGS - description of marked objects

- camera body;

- ultrasonic acoustic pressure source;

- lower part of the fortification;

- upper part of the fortification;

-pressure disc;

- pressure disc mounting screw;

- pressure disc fastening nut;

- fastening screw for fastening parts;

- fastening nut for fastening parts;

- acoustic emitter;

- concentrator;

- piezoelectric ring;

- counterweight;

- electrical signal generator;

- inner diameter of the camera body;

- angular distance;

- Langevin type transducer.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the ultrasonic acoustic agglomeration chamber is described with reference to the drawings, but the technical implementation of the chamber is not limited to the presented method. Various implementation methods, modifications and improvements are possible.

Detailed description of the ultrasonic acoustic agglomeration chamber: The ultrasonic acoustic agglomeration chamber consists of three ultrasonic acoustic pressure sources (2) which are formed from three Langevin-type transducers (17) each of which consists of two piezoelectric rings (12) which are placed between a counterweight (13) and a concentrator (11) while disc-shaped acoustic radiators (10) are permanently placed at the free ends of the concentrators (11). The geometric characteristics of the disc-shaped acoustic radiators (10) and the Langevin-type transducers (17) are selected so that the resonant frequency of the first bending vibration mode of the disc-shaped radiators (10) coincides with the resonant frequency of the first longitudinal vibration mode of the Langevin-type transducer (17). The ultrasonic acoustic pressure sources (2) are fixed through the upper and lower mounting parts (2, 4), which are attached to the chamber body (1) through the mounting screws of the mounting parts and the nuts of the mounting parts (8, 9) in such a way that the outer surfaces of the acoustic radiators (10) and the inner diameter (15) of the chamber body (1) coincide tangentially until the ultrasonic acoustic pressure sources (2) are fixed to the upper mounting part (4) through the pressure discs (5) using the pressure disc screws and nuts (6, 7) through friction force. The angular distance (16) of the ultrasonic acoustic pressure sources (2) around the longitudinal axis of symmetry of the chamber housing (1) is selected so that it is the same among all ultrasonic acoustic pressure sources (2), and the inner diameter (15) of the chamber housing is selected so that the ratio of the acoustic wavelength of each ultrasonic acoustic pressure source (2) to the inner diameter (15) of the housing is an integer.

Description of the operation of the ultrasonic acoustic agglomeration chamber:

In the ultrasonic acoustic agglomeration chamber, three overlapping acoustic fields of high intensity are formed when all three ultrasonic acoustic pressure sources (2) Langevin transducers (17) are synchronously affected by an electrical signal generator (14) with a harmonic electrical signal, the frequency of which is selected to coincide with the resonant frequencies of the ultrasonic acoustic pressure sources (2) while the amplitude of the electrical signal is selected to ensure an acoustic pressure suitable for the acoustic agglomeration process. Longitudinal mechanical vibrations are excited in the Langevin transducers (17), which are transformed into bending vibrations of the acoustic radiator (10) in a direction perpendicular to the radiator plane, as a result of which overlapping acoustic fields are created.

The overlapping of the generated acoustic fields is obtained in the chamber (1), which ensures the multidirectional effect of the acoustic fields on the solid particles until the ratio of the length of the generated acoustic waves to the inner diameter of the housing (15) is an integer, which ensures the effect of a standing wave in the inner diameter of the chamber housing.

Application example of ultrasonic acoustic agglomeration chamber:

Ultrasonic acoustic agglomeration chamber can be applied in industrial air purification systems where there is a need to agglomerate fine and ultra-fine solid particles in the air stream, thus increasing the possibility of their filtration by mechanical, electrostatic or other types of filters. Ultrasonic acoustic agglomeration chamber can be used in industrial air filtration systems used in metallurgical, chemical or pharmaceutical production processes, in order to reduce environmental pollution by fine or ultra-fine solid particles.

Claims (4)

DEFINITION OF THE INVENTION 1. Ultrasonic acoustic agglomeration chamber consisting of a chamber body (1), three ultrasonic acoustic pressure sources (2), three upper and lower mounting parts (3,4) and three pressure discs (5) interconnected by fastening bolts and nuts (8,9) of the mounting parts and fastening bolts and nuts (6,7) of the pressure discs, characterized in that the angular arrangement of the ultrasonic acoustic pressure sources (2) around the longitudinal axis of symmetry of the chamber body (1), synchronously exciting the three ultrasonic acoustic pressure sources (2), forms three overlapping acoustic fields in the inner diameter (15) of the chamber body. 2. Ultrasonic acoustic agglomeration chamber according to claim 1, characterized in that the ultrasonic acoustic pressure source (2) consists of a piezoelectric Langevin type transducer (17), at one end of which an acoustic pressure emitter (10) is permanently attached. 3. Ultrasonic acoustic agglomeration chamber according to claim 1, characterized in that the inner diameter (15) of the chamber body (1) is selected such that the ratio of the acoustic wavelengths generated by the acoustic pressure sources (2) to the inner diameter (15) of the chamber body is an integer, and the geometric characteristics of the piezoelectric Langevin transducer (17) and the acoustic radiator (10) are selected such that the resonant frequency of the first bending vibration mode of the acoustic radiator (10) coincides with the resonant frequency of the first longitudinal vibration mode of the Langevin transducer (17). 4. Ultrasonic acoustic agglomeration chamber according to claim 1, characterized in that the acoustic pressure sources (2) are mounted so that the outer flat surface of the disk-shaped acoustic radiator (10) coincides with a tangent line to the inner diameter (15) of the chamber body (1).