RU2262397C1 - Method of ultrasonic cleaning of surfaces and a device for its realization - Google Patents

Abstract

FIELD: ultrasonic equipment.

SUBSTANCE: the group of inventions is pertaining to ultrasonic equipment and may be used in the technological equipment at cleaning component parts in a liquid medium. The method provide for creation of conditions for a regular flow of a working actuating medium in a bath by a serial short-time switching off of emitters mounted in apexes and on the sides of regular polygons, radiuses of the given circumferences of which are aliquot to an odd number of quarters of a wave length of the ultrasonic oscillations excited in a material of the bath, on a distance from each other equal to a quarter of the length of the indicated wave. The device for realization of the method contains emitters and generators of alternating electric voltage. For formation of a regular flow of the working medium in the bath by a serial short-time witching the emitters off the generators are made autonomous, and each of the emitters is fused to an output of one generator, input of which is fused to an output of the switchboard, and the input of the switchboard is fused to the output of the processor. The group of inventions ensures an increase of efficiency of technological ultrasonic installations at the expense of decrease of a share of the power used for creation of motion of the working medium, and also a decrease of time used for cleaning at the expense of removal from a cleaned surface of decomposition products of a contaminant as they appear.

EFFECT: the group of inventions ensures increased efficiency of technological ultrasonic installations, decreased power consumption and time used for the surfaces cleaning.

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Description

The invention relates to ultrasonic technology and can be used in technological equipment when cleaning parts in a liquid medium.

Modern technical detergents work on the principle of cleavage of dirt from surfaces. When exposed to contaminated surfaces, microscopic cracks form in the contaminant layer. The cleaning solution penetrates into them and concentrates in the cavities formed between the treated surface and the contaminant. Further, the solution concentrated in the cavities creates a proppant effect and tears the pollutant from the surface. For effective operation, passive finding of parts in the washing solution is not enough. The solution should find a microcrack in the contamination and penetrate into it. Only in this situation will he be able to split off the dirt from the surface being treated, and for this he needs to create an appropriate disturbance. The most effective source of such a disturbance is ultrasound. However, when cleaning surfaces from various solid pollutants with increased adhesion and diffusion ability (carbon deposits from fuel combustion products, scale, rust, scale, etc.), to improve the efficiency and reduce the process time, it is necessary to periodically remove a thin surface from the treated surface layer of decay products of the pollutant. For this, various methods are used: sparging, swaying of the workpiece in the working medium, periodic rinsing of the treated surface with flowing working fluid. To create the movement of the working medium, mechanical devices, compressors and pumps of various types are usually used.

A known bath for ultrasonic processing in a liquid, with the emitters located at the vertices and the center of a regular hexagon, the radius of the circumference of which λ / 4 is a multiple of an odd number of quarters of the length of the transverse ultrasonic wave of transverse ultrasonic vibrations excited in the bath material [1]. This arrangement of emitters ensures uniformity of the acoustic field by eliminating the superposition of mechanical and acoustic vibrations between adjacent emitters. However, in a homogeneous acoustic field, the flow of the working medium is almost impossible due to the absence of drops in its intensity in its local areas.

Known ultrasonic transducer containing a source of three-phase alternating electric voltage with a symmetric phase shift and a radiator with several vibrators located at the vertices of equilateral triangles, conjugated by their sides [2]. In such a transducer, an instantaneous difference in the intensity of the ultrasonic field in its local areas leads to the formation of vortices in the working medium above the transducer. However, the low value of the pressure drop does not allow to create conditions for the emergence of a regular flow of the medium.

The technical result of the invention is to increase the efficiency of ultrasonic processing units by creating a regular flow of the working medium in the bath.

This result is achieved by creating a regular flow of the working medium in the bath by alternately briefly turning off the emitters installed at the vertices and sides of regular polygons, the radii of the circumscribed circles of which are a multiple of an odd number of quarters of the wavelength of ultrasonic vibrations excited in the bath material at a distance from a friend equal to a quarter of the length of the specified wave.

 This result is also achieved by the fact that the diametrically located emitters are simultaneously turned off.

 This result is also achieved by a device for ultrasonic cleaning of surfaces, containing emitters and alternating voltage generators, in which, to create a regular flow of the working medium in the bath by alternately briefly turning off the emitters, the generators are autonomous, and each of the emitters is connected to the output of one generator, the input of which connected to the output of the switch, and the input of the switch is connected to the output of the processor.

 Emitters located at the vertices and sides of regular polygons at the same distance λ / 4 from each other (Fig. 1) are connected to autonomous alternating voltage generators. Each of the generators is connected by one of its inputs to the output of the switch, providing its short-term shutdown. The frequency of shutdowns, the time period of the off state, the sequence of shutdowns of the generators sets the processor (figure 2). When the generator is turned off, the corresponding emitter is turned off. When one of the emitters is turned off in the working medium, an instantaneous pressure drop δP is created between the region of a homogeneous acoustic field of maximum intensity located above the working emitters and the region of zero field intensity located above the switched off emitter. This leads to a flow of the working medium from the high-pressure region to the low-pressure region. When you turn on the first emitter and turn off the next emitter, located next to the right or left, a new pressure drop δP appears and, as a result, the flow of the working medium into the region above the turned off emitter. Thus, the alternate shutdown of the emitters provides regularity and directionality of the flow of the working medium.

When emitters are placed at a distance equal to λ / 4, at the vertices and sides of polygons, the radii of the circumscribed circles of which are multiples of λ / 4, and at the same time, the emitters located on the same diameter of these circles are turned off alternately, the effect of regular movement of the working medium relative to the motionless work surface is achieved .

During the experimental verification of the converter at the resonant frequency of the emitters of 33 kHz with a switching frequency of the switch from 12 Hz to 1 kHz, a rather high efficiency of the converter was obtained. The flow rate of the working medium ranged from 0.5 to 5 cm / s.

EFFECT: increased efficiency of technological ultrasonic units is achieved by reducing by 50% the share of energy used to create movement of the working medium, reducing the cleaning time by 15-20% by removing pollutant decay products from the surface to be cleaned as they arise.

SOURCES OF INFORMATION

1. USSR copyright certificate No. 578127. Bathtub for ultrasonic processing. MKI V 08 V 3/12. Publ. Bull. No. 40, 1977

2. USSR copyright certificate No. 359060. Ultrasonic transducer. MKI V 06 V 1/06. Publ. Bull. No. 35, 1973

Claims (3)

1. The method of ultrasonic cleaning of surfaces, which consists in creating a regular flow of the working medium in the bath by alternately briefly turning off the emitters installed at the vertices and sides of regular polygons, the radii of the circles described are multiples of an odd number of quarters of the wavelength of ultrasonic vibrations excited in the bath material, a distance from each other equal to a quarter of the length of the specified wave. 2. The method according to claim 1, characterized in that the diametrically located emitters are simultaneously turned off. 3. Device for ultrasonic cleaning of surfaces, containing emitters and generators of alternating electric voltage, characterized in that for creating a regular flow of the working medium in the bath by alternately briefly turning off the emitters, the generators are autonomous and each of the emitters is connected to the output of one generator, the input of which is connected to the output of the switch, and the input of the switch is connected to the output of the processor.

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