WO2012165996A1

WO2012165996A1 - Piezoelectric device for ultrasonic cleaning baths

Info

Publication number: WO2012165996A1
Application number: PCT/RU2011/000650
Authority: WO
Inventors: Олег Григорьевич ПАВЛЕНКО
Original assignee: Pavlenko Oleg Grigorievich
Priority date: 2011-06-01
Filing date: 2011-08-26
Publication date: 2012-12-06

Abstract

The invention relates to ultrasonic cleaning of aviation filters for hydraulic, fuel and oil systems. The piezoelectric device for ultrasonic cleaning baths comprises, connected to one another in series: a passive lining consisting of steel; piezoelectric elements attached to the passive lining and connected electrically to an ultrasonic oscillations frequency generator; and a radiating lining consisting of aluminium or an aluminium alloy or Duralumin in the form of a truncated cone which is attached by the smaller base to the piezoelectric element. The ratio of the height of the passive lining to the height of the radiating lining is equal to or greater than unity given a number of piezoelectric elements which is equal to two or more pairs. Whereas the piezoelectric device is capable of being attached to a bath with washing liquid for the item to be cleaned or of being submersed in a bath with washing liquid for the item to be cleaned.

Description

PIEZOELECTRIC DEVICE FOR ULTRASONIC

BATH CLEANING

Technical field

The invention relates to ultrasonic cleaning of contaminated parts and assemblies, including aviation filters and filter elements for hydraulic, fuel and oil systems of aircraft (aircraft - aircraft and helicopters), in a washing liquid using technological effects of developed cavitation. The predominant consideration of aviation filters, primarily, is caused both by their use to ensure flight safety of aircraft, and by the fact that for comparative analysis of the effectiveness of various existing piezoelectric installations it is useful to test aviation filters as cleaned parts, since their cleaning is strictly regulated by metrological standards .

State of the art

For decades, the only type of ultrasonic equipment used to clean aircraft filters in aviation has been the magnetostrictive type. The piezoelectric type of installations produced in the world since 1950 was not used for cleaning aviation filters in aviation.

03.22.1996, Pavlenko O.G. patented a utility model (RU N ° 3704, V08VZ / 12, published on March 16, 1997) (adopted as a prototype), in which it was first proposed to use piezoelectric plants to clean aircraft filters.

This patent describes a piezoelectric device for ultrasonic cleaning of aviation filters and filter elements, containing one ultrasonic generator, N power amplifiers, the outputs of which are connected respectively to the inputs of N ultrasonic transducers, a bath with a washing solution, N - 1 ultrasonic generators, N frequency-locked units and N protection blocks overload, and the output of each ultrasonic generator is connected to the input of the corresponding overload protection unit, the output of which is connected to the input of the corresponding power amplifier, to the control input of each ultrasonic generator is connected the output of the corresponding frequency control unit, connected by its input to the electrical output of the corresponding ultrasonic transducer, while the transducers themselves are mounted on a removable frame, which, depending on the configuration and size of the workpieces Aviation filters can be placed inside the bathtub in an arbitrary position, and each ultrasonic transducer contains emitting and passive overlays, between which piezoelectric elements are located.

This patent was the result of a two-year prior verification and trial operation at the Sheremetyevsk Aviation Technical Center of a piezoelectric installation for cleaning air filters, created by the inventor. A feature of the patented device and its method of action is that the weight, energy and price parameters were reduced by 10 times compared to magnetostrictive cleaning units.

Further development of this topic in terms of optimizing the electrical parameters of piezoelectric installations is reflected in patents RU NsNs 2193932, 2193931, 2193930, 49740. However, these patents relate to improving the designs of generators for piezoelectric devices and identifying new operational applications, and improvement of the design of the piezoelectric emitters was not considered.

The practice of using piezoelectric installations for cleaning contaminated elements and assemblies shows the need to control and account for the consumed electrical energy in relation to the ultrasonic process that provides cleaning. This is due not only to savings energy, but also because cleaning under stationary conditions requires the deployment of aircraft directly at the location of the treatment plant, and the cleaning process itself requires a fairly long time. Such restrictions seriously affect the flight schedule of aircraft.

The solution to the problem is effective and for quick guaranteed cleaning is associated not only with the design of the generator itself, but also with the piezoelectric emitting device. As a rule, ultrasonic cleaning devices use an ultrasonic transducer containing emitting and passive plates, between which a pair of piezoelectric elements is located. This design of the piezoelectric device is shown in the drawings for the patent RU .Ns 3704 and RU 60791 (H01L41 / 083, H04R17 / 10, published on January 27, 2007, patent holder O.G. Pavlenko). But in the patent RU -N ° 60791 for the first time a drawing of a piezoelectric device was given, in which four pairs of piezoelectric elements are located between the radiating and passive plates. This example is one of the essential points and considered the possibility of increasing the pairs of piezoelectric elements to solve the problem of increasing the frequency range and increasing the efficiency of ultrasonic radiation and the apparatus (installation) as a whole. These studies show the possibility and necessity of optimizing both the design of the piezoelectric device and its dimensions to increase efficiency, reduce energy consumption and minimize overall weight indicators. This will make it possible to move from bulky, ineffective and time-consuming stationary treatment plants to small-sized devices that can be powered by an on-board source and allow cleaning on board the aircraft in the shortest possible time.

Disclosure of invention

The present invention is directed to solving the technical problem of changing the parameters of piezoelectric emitters and their working conditions in a liquid medium. The technical result achieved in this case is to increase the efficiency of the piezoelectric device for ultrasonic cleaning, including such parts as aviation filters, filter elements and filter bags by reducing cleaning time while improving the quality of cleaning itself and increasing the reliability of operation by increasing the efficiency of the device and reducing heating emitters.

The specified technical result is achieved in that in a piezoelectric transducer for ultrasonic cleaning baths containing a passive steel plate in series, piezoelectric elements connected electrically with a generator and a radiating plate of aluminum or aluminum alloy made in the form of a truncated cone, a smaller base attached to the piezoelectric element, the radiating and passive plates are made of different heights, the ratio of the height of the passive plate to the height of the radiating plate is selected p or more units when the number of pairs of piezoelectric elements is two or more.

These features are significant and are interconnected with the formation of a stable set of essential features sufficient to obtain the desired technical result.

Description of the figures of the drawings

The present invention is illustrated by specific examples of execution, which, however, are not the only possible, but clearly demonstrate the ability to achieve the desired technical result.

In FIG. 1 is a diagram of a piezoelectric device;

FIG. 2 - piezoelectric device, the first example of the placement of the piezoelectric emitter;

FIG. 3 - a piezoelectric device, a second example of the placement of a piezoelectric emitter; FIG. 4 - portable immersion sealed piezoelectric device;

FIG. 5 is a piezoelectric device with focusing piezoelectric emitters of a structure according to the present invention;

FIG. 6 is an example of using a portable piezoelectric device for any capacity.

The best embodiments of the invention

The piezoelectric device for ultrasonic cleaning in a liquid medium of nodes and elements of any type and any structural complexity, including such critical nodes as aviation filters and filter elements, shown in figure 1, can improve the efficiency of the piezoelectric device for ultrasonic cleaning and expand the frequency range the functioning of piezoelectric emitters and reduce cleaning time while improving the quality of the cleaning itself.

This piezoelectric device contains at least one piezoelectric emitter (if there are several channels, then each channel has a separate piezoelectric emitter) made in the form of a prefabricated structure consisting of a passive plate 1 made of steel, piezoelectric elements 2 connected in series (a set of piezoelectric elements is performed in equal to two pairs of piezoelectric elements or more than two pairs of these elements) (made in the form of piezoceramic washers), which are electrically connected to the generator 3 form Hovhan frequency ultrasonic vibrations, and the radiating laths 4 of aluminum or aluminum alloy, constructed as a truncated cone, the small base attached to the piezoelement. A feature of the emitter according to this utility model is that as a result of experiments, a new relationship between design parameters of the emitter elements. Moreover, the radiating and passive pads are made of different heights.

A feature of the emitter according to the present invention is that as a result of the experiments, a new relationship is established between the design parameters of the emitter elements and the number of piezoelectric elements in the set to increase the efficiency and reduce the heating of the emitter. So, the radiating and passive plates are made of different heights, the ratio of the height of the passive steel plate h ₂ to the height of the emitter hi is equal to or more than one. Unlike typical piezoelectric transducers for cleaning air filters, in which only one pair of piezoelectric elements is used and in which the radiating aluminum plate is larger in height of the back steel plate.

It allowed:

1. Increase the efficiency of the device.

2. To increase the operating frequency range of the radiation compared with the emitter made with one pair of piezoelectric elements.

3. Increase efficiency.

4. To reduce the heating of the emitter and increase the reliability of its operation. The absolute value of the frequency is selected by increasing or decreasing the height of the radiating and passive plates. With an increase in the absolute dimensions of the heights of these parts and an increase in the number of piezoelectric elements, the frequency of the transducer will be less, and vice versa, with a decrease in the absolute dimensions of these parts, the frequency of the transducer will be greater.

Unlike typical piezoelectric transducers for cleaning air filters, in which only one pair of piezoelectric elements is used and in which the radiating aluminum plate is higher in height than the back steel creature of the claimed utility model, it consists in increasing the number of pairs of piezoelectric elements and changing the ratio of the heights of the pads. The device allows to increase the efficiency of the device and reduce the heating of the emitter and increase the reliability of its operation.

The piezoelectric device for ultrasonic cleaning of aviation filters and filter elements is carried out in a stationary version, in which the piezoelectric emitter can be glued with a radiating pad to the bottom of the bath (Fig. 2), filled with washing liquid for the product to be cleaned, or a landing nest with a hole and an emitter of its own are formed radiating pad is fixed in this slot (Fig. 3). In the first case, the oscillations are transmitted to the washing liquid through the wall of the bath, in the second case, the emitter has direct contact with the washing liquid and the oscillations are transmitted directly to the liquid. The piezoelectric emitter can be made in the form of a sealed module (separate unit), immersed in a bath with washing liquid for the product to be cleaned (Fig. 4).

The use of such submersible (practical) or attached emitters on the bottom of the bath at an angle to each other allows one to obtain radiation focusing, which makes it possible to obtain an enhanced cleaning effect (Fig. 5)

Given the low power consumption, the piezoelectric device for ultrasonic cleaning of aviation filters and filter elements can be portable (Fig. 4), in which the piezoelectric emitter is made as a separate unit in the housing 7 and is connected to the generator of the formation of the frequency of ultrasonic vibrations by an electric cable 8 to ensure immersion of the specified emitter in a container 9 with a washing liquid. In a portable design, the emitter may have a suspension 10 for securing it when cleaning using a suitable container 9 (Fig. 6).

For the operation of the piezoelectric device, an ultrasonic generator is used, the design of which is described in RU Ν ° 3704. To increase the cleaning efficiency, the large base of the radiating lining (Fig. 1) can be made non-planar, for example, a recess with a flat bottom and an inclined wall can be made on this base, or this recess can be profiled, the surface of which is a fragment of a second-order surface. When using six or more pairs of piezoelectric elements, the cavitation mode is enhanced, despite the decrease in current consumption, compared with the use of typical traditional designs of piezoelectric emitters to obtain the same acoustic power, that is, the efficiency of the electro-acoustic system increases. This design feature of such a new emitter was noted in patent 60791 and is essential for the claimed invention.

For an ultrasonic piezoelectric device for cleaning aviation filter elements and filter bags, washing liquid or alkaline washing solutions, or liquids available on board the aircraft, for example, fuel intended for operation of engines or an engine, or oil intended for operation of oil or hydraulic systems of an aircraft, are used, and washing an ultrasonic generator included in the set of an ultrasonic piezoelectric device for cleaning aviation filter elements and filters paths, possible from airborne or ground-based sources of direct or alternating voltage.

In a bath with the required dimensions, a frame with an ultrasonic piezoelectric emitter in each of the N channels and processed aviation filter elements and filter bags are installed in a certain position, after which the washing liquid is poured into it and the supply voltage is turned on, the bath body itself can perform the function of the frame for piezoelectric emitters, when this piezoelectric emitter is installed on the bottom of the bath (or under the bottom of the bath) or on its side walls. Electrical signals generated by the generator in in the form of packs of radio pulses (or in continuous mode) of ultrasonic frequency, through the overload protection units, they are supplied to the corresponding power amplifiers and then through hermetic cables to the ultrasonic piezoelectric emitters. Using the blocks of automatic frequency adjustment introduced into the feedback circuit of each channel, the necessary adjustment of the output frequencies of the radio pulses (or continuous oscillations) of the ultrasonic generators is carried out. As a result, macro-flows with different directions of speeds and developed cavitation are created inside the washing liquid, which, ultimately, leads to an increase in the quality of cleaning aviation filter elements and filter bags.

This utility model allows for efficient high-quality cleaning of various types of filter elements and filter bags both in the erosion mode, and with the erosion-free effect or in the combined mode, depending on the requirements for products. In this case, the cleaning process is in automatic mode to control the degree of cleaning according to the testimony of a device that responds to pressure differences between the filter cavity and the environment. In this case, it becomes possible to operate the device in a wide range of frequencies, which significantly increases the intensity of the cleaning process and reduces the time of this process.

Industrial applicability

The present invention is industrially applicable, as it can be implemented using known means and techniques used in electrical engineering in the manufacture of electrical devices.

Claims

Claim

1. A piezoelectric device for ultrasonic cleaning baths, containing a passive plate made of steel connected in series, piezoelectric elements connected to a passive plate and connected electrically to the generator for generating the frequency of ultrasonic vibrations, and a radiating plate made of aluminum or aluminum alloy or duralumin, made in the form of a truncated cone, a smaller base attached to the piezoelectric element, while the radiating and passive pads are made of different heights, characterized in that about wearing the height of the passive pad to the height of the radiating pad is made equal to or greater than one when the number of piezoelectric elements is two or more pairs, while the piezoelectric device is configured to attach to the bath with washing liquid for the product to be cleaned or immersed in the bath with washing liquid for the cleaned products.

2. The piezoelectric device according to claim 1, characterized in that the surface of the larger base of the radiating lining is made non-planar.

3. The piezoelectric device according to claim 2, characterized in that in the larger base of the radiating lining there is a recess with a flat bottom and an inclined wall or a profile recess, the surface of which is a fragment of a second-order surface.