RU2313408C1 - Device for ultrasonic cleaning of items - Google Patents

Abstract

FIELD: ultrasonic engineering.

SUBSTANCE: device can be sued in different branches of industry fro cleaning different parts from pollution and for domestic appliances for cleaning textile items. Device has radiators belonging to the same plane, which radiators are connected to ac voltage generator. Generator is made for change in frequency within f_l-f_h range. Irradiators are chosen with resonant frequencies belonging to f_l-f_h frequency range, where f_l is lower value of frequency and f_h is higher value of frequency of frequency range.

EFFECT: improved efficiency; reduced cost of operation.

4 dwg

Description

The invention relates to ultrasound equipment and can be used in various industries for cleaning various parts from contaminants, as well as in everyday life for cleaning textile products.

Modern ultrasonic washing devices work on the principle of creating a sufficiently powerful ultrasonic field in the entire volume of the washing liquid. Under the influence of ultrasound, the detergent effectively penetrates into the pollution due to the formation of microcracks and pores in it and detaches it from the surface being treated. However, to increase the efficiency of cleaning, it is necessary to create a movement of the working medium. In industrial plants, various methods of mechanical mixing are used to create an orderly movement of the working fluid. The proposed device allows you to create an ordered movement of the working fluid by creating an inhomogeneous acoustic field in the volume of the working fluid. The inhomogeneity of the field leads to the appearance of increased pressure in the local areas of the volume of the working fluid. The liquid under the action of the pressure difference flows from the high pressure region to the low region.

A well-known bath for ultrasonic processing in liquid, with the emitters located at the vertices and center of a regular hexagon, the radius of the circumference described is a multiple of an odd number of quarters of the length of the transverse ultrasonic wave excited in the bath material (USSR Author's Certificate No. 578127, MKI: B08B 3/12). This arrangement of emitters provides a uniform 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 differences in its intensity in its local areas, which leads to insufficient quality cleaning of products.

A known ultrasonic transducer containing a source of three-phase AC voltage with a symmetrical phase shift and a radiator with several vibrators located at the vertices of equilateral triangles conjugated by their sides (USSR Author's Certificate No. 359060, MKI: V06V 1/06).

In such a transducer, the inhomogeneity of the acoustic field leads to the formation of vortices and creates a certain pressure drop. However, the magnitude of this difference is not large enough to create an ordered movement of the working fluid, which also negatively affects the quality of cleaning products.

The closest in technical essence to the claimed is a device for ultrasonic cleaning of surfaces, containing emitters and generators of alternating electric voltage, 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 is connected to the output of the switch, and the input of the switch is connected to the output of the processor (RF Patent for the invention No. 2262 397, IPC: B08B 3/12).

A disadvantage of the known device is the need to use in its design a large number of generators corresponding to the number of emitters and a switch. This significantly increases the cost of its production and increases its cost. A disadvantage of the known device is its high power consumption.

The invention is aimed at solving the problem of creating an economical device for cleaning products while ensuring high quality cleaning products.

The problem is solved in that in the device for ultrasonic cleaning of products containing emitters lying in the same plane, connected to an alternating voltage generator, according to the invention, the generator is configured to change the frequency in the range f _n -f _in , and the emitters are selected with resonant frequencies from a given frequency range, where f _n is the lower frequency value from the frequency range, f _{in the} upper frequency value. As a generator, a oscillating frequency generator can be used, and some emitters can have the same resonant frequency. In addition, in one embodiment of the device, emitters with the same resonant frequency can be located on the radii of concentric circles at a distance from each other equal to a quarter of the wavelength for the average frequency of the operating range f _n -f _in .

The technical result obtained by using the invention is to eliminate the disadvantages of the prototype listed above, and ultimately provides an intensification of the process and, as a result, a decrease in the duration of the cleaning process while reducing energy consumption by 10-15% and obtaining high quality cleaning.

The invention is illustrated by drawings, where figure 1 schematically shows the inventive device with N emitters, where N is the serial number of the emitter, figure 2 is one of the options for the location of the emitters, figure 3 is a special case of the device, figure 4 is a block -schema oscillating frequency generator (GKCh). The positions denote: 1 - the master oscillator of the oscillating frequency, 2 - the node forming the time delay, 3 - the pre-amplifier 4 - output stage, 5 - the network rectifier with a filter, 6 - the power supply of the control circuit, 7 - emitter, 8 - generator, 9 - processor, 10 - oscillating frequency generator (GKCh).

The invention is a device containing N emitters 7 lying in the same plane, and an alternating voltage generator 8, and for creating a wave-like motion of the working medium in the bath by successive excitation of the emitters, the generator is made in the form of a controlled generator with the ability to change the frequency in the range f _n - f _in , where f _n - the lower limit of the range, af _in - the upper limit (figure 1). A change in the frequency of the generator is controlled by the processor 9, while the change in frequency can be performed both discretely and continuously. The emitters are connected to the generator in parallel and have different resonant frequencies f _n from the frequency range f _n -f _in . The numerical values of the parameters f _n and f _{in are} determined by the resonant characteristics of the emitters used. The device may use both piezoceramic and magnetostrictive emitters. Several emitters with the same resonant frequency can be used in the device at once, and they can be arranged in an orderly manner, for example, in the order of increasing the resonant frequency or arbitrarily. One of the options for the ordered arrangement of emitters can be their placement in one plane, for example, on the bottom of the bath in a radial direction from the center of the bottom of the bath. The distance between adjacent emitters of the radial direction can be selected equal to a quarter of the wavelength for the average frequency of the operating range f _n -f _in (size A), while at the same radius there are emitters having the same resonant frequency f _n (figure 2) . A special case is the use of the apparatus swept frequency generator f _n -f _range, wherein the processor of the device can be excluded (Figure 3).

The device works as follows: the generator converts the voltage of the mains into an alternating voltage of the frequency that is set by the processor. This alternating voltage is supplied simultaneously to all emitters. Emitters convert electrical energy into acoustic wave energy. If the frequency of the generator coincides with the resonant frequency of one emitter or group of emitters, then the amplitude of their oscillations becomes greater than the amplitude of the oscillations of the other emitters. This leads to the formation of vortices in the volume of the working fluid above these emitters. A pressure differential ΔP is created between the region of the small acoustic field and the region with its maximum intensity. There is a wavelike movement of the working fluid from the high-pressure region to the low-pressure region. When the generator frequency changes, emitters with a different resonance frequency are located in a different region, and the process repeats. When using a swept frequency generator is a continuous range of frequencies f _n -f scanning _in the bottom up and vice versa. In the case of an ordered arrangement of emitters, depending on their resonant frequency, they are sequentially excited and accordingly directed movement of the working fluid is created.

The inventive design was implemented in a laboratory setup. The controlled generator was made in the form of a generator of a sweeping frequency range f _n -f _in . The generator is assembled according to a typical circuit consisting of the following main units: a master oscillator of the oscillating frequency 1, a node for generating a time delay 2, a preliminary amplifier 3, an output stage 4, as well as a network rectifier with a filter 5 and a power supply 6 of the control circuit. The control circuit includes nodes 1-3 (figure 4). Six emitters with a diameter of 50 mm with resonant frequencies of 40, 42, 44, 46, 48, 50 kHz, made of PZT-19 piezoceramics with silver plates, are connected in parallel with the generator. To prevent a short circuit, the emitters were sealed with a waterproof elastic sealant. The emitters were placed at the bottom of the bathtub in random order. The oscillator oscillation band was 10 kHz (f _n - 40 kHz, f _in - 50 kHz), the oscillation period was 5 seconds. When scanning a given frequency range, sequential excitation of the emitters occurred and a wave-like motion of the liquid in the bath volume was created.

The inventive device, in addition to improving the above characteristics, improves the cleaning performance.

Claims (4)

1. Device for ultrasonic cleaning of products containing emitters lying in the same plane, connected to an alternating voltage generator, characterized in that the generator is configured to change the frequency in the range f _n -f _in , and the emitters are selected with resonant frequencies from the frequency range f _n -f _in where f _n is the lower frequency value from the frequency range, f _{in the} upper frequency value. 2. The device according to claim 1, characterized in that the oscillating frequency generator is selected as the generator. 3. The device according to claim 1 or 2, characterized in that some of the emitters have the same resonant frequency. 4. The device according to claim 3, characterized in that the emitters with the same resonant frequency are located on the radii of concentric circles at a distance from each other, equal to a quarter of the wavelength for the average frequency of the operating range f _n -f _in .

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