RU2796645C2 - Plasma treatment device and method for adjusting the size of the contact surface of the plasma treatment device to the dimensions of the surface to be treated - Google Patents

Abstract

FIELD: plasma technology.

SUBSTANCE: in a plasma treatment device for conducting a plasma dielectric barrier discharge on a surface to be treated, containing a flat electrode block (4) having a processing side and a control block (11), which supplies at least one electrode (19) of the electrode block (4) with a high-voltage an alternating potential for generating the power necessary to produce a plasma between said at least one electrode (19) and the counter electrode forming the reference potential. At least one electrode (19) receiving said high-voltage alternating potential is shielded by a flat dielectric (7) at least from the processing side. The flat electrode block is made with the possibility of reducing the dimensions of its contact surface on the surface to be treated to adjust to the dimensions of the surface to be treated. Correction of the contact surface of the flat electrode block (4) does not cause problems due to the fact that the control block (11) contains a device (14) for determining the size of the contact surface to be corrected and a control device for setting the power output to at least one specified electrode (19) in depending on the size of the contact surface.

EFFECT: increased efficiency of plasma treatment.

10 cl, 13 dwg

Description

The present invention relates to a plasma treatment apparatus for conducting a plasma dielectric barrier discharge on a surface to be treated, which comprises a flat electrode assembly having a treatment side and a control unit that supplies at least one electrode of the electrode assembly with a high voltage alternating potential for the power required for producing a plasma between said at least one electrode and a counter electrode that creates a reference potential, wherein said at least one electrode receiving said high-voltage alternating potential is shielded with a flat dielectric at least from the processing side, and moreover, the flat electrode block is made with the possibility of reducing the dimensions its contact surface on the surface to be processed to adjust to the dimensions of the surface to be processed.

The present invention further relates to a method for adjusting the size of the contact surface of a flat electrode unit having a treatment side of a plasma treatment device for conducting a plasma dielectric barrier discharge on the surface to be treated to the dimensions of the surface to be treated, wherein the control unit supplies to said at least one electrode of the electrode unit a high voltage alternating potential for the power required to produce a plasma between said at least one electrode and a counter electrode creating a reference potential, wherein said at least one electrode receiving said high voltage alternating potential is shielded at least on the processing side by a flat dielectric, and moreover the specified contact surface of the electrode block is reduced to adjust for the dimensions of the surface to be treated.

Plasma treatment devices for conducting a plasma dielectric barrier discharge on a surface to be treated are known in numerous embodiments. At the same time, a prerequisite for the formation of plasma on the surface to be treated is the supply of a high-voltage alternating potential to at least one electrode of the electrode unit of the plasma treatment device. The electrode block can then have one or more electrodes, to which an alternating voltage potential is applied, either a ground electrode is provided or the surface to be treated serves as a counter electrode, if the material of the surface to be treated has sufficient conductivity. An example of a counter electrode forming a reference potential is a treatment on a human or animal body, which, if necessary as a "floating" counter electrode, only forms a slightly fluctuating reference potential.

If the electrode block itself contains a counter electrode having a reference potential, then an alternating field arises between said at least one electrode controlled by said high-voltage alternating potential and the counter electrode, which leads to plasma formation on the surface of the electrode block. The plasma treatment carried out in this way is less intensive than when using the surface to be treated as a counter electrode.

It has long been known to flatten electrode blocks in order to be able to treat a large surface, wherein such an electrode block can rest directly on the surface to be treated with its contact surface. In this case, this contact surface can be provided with spacer elements so that between the surface to be processed and the dielectric shielding the electrode, a gas space or an air space for the formation of the plasma is defined.

For production reasons, it is not economical to produce electrode blocks in a wide range of sizes in order to ensure that the size of the electrode block and its contact surface match well with the maximum possible number of sizes of the surface to be treated. This problem arises in particular when said surface to be treated is a wound surface on a living body, since this wound surface can have very different dimensions.

It is known from DE 10 2014 220 488 A1 to connect various electrode assemblies to the control unit of a plasma treatment device. In this case, it is possible to equip this electrode unit with a chip in whose memory the electrical signals required for this electrode unit and, if necessary, for special applications are stored. In this case, the corresponding size of the produced electrode block can also be taken into account. However, this implies that the electrode blocks are pre-produced in various sizes, whereby the aforementioned disadvantages arise.

In order to overcome these shortcomings, electrode blocks have already been proposed in which the contact surface can be reduced in order to adjust to the respective surface to be treated. An electrode block is known from EP 2 723 447 B1, which consists of a narrow strip wound in a spiral manner, in which at least one electrode extends in the longitudinal direction of this strip. The reduction in this essentially circular contact surface is achieved by shortening this helically twisted strip by cutting off part of the length of the strip forming the outer coil (outer coils). Safe contact with the remaining electrode block is made at the cut end. Such a device is known from DE 10 2017 104 852 A1, according to which the helical strip can form a square or rectangular electrode block and can be provided with predetermined fracture points, in which shortening of the strip length is possible by tearing off. Here, too, there is a touch-protected contact with the strip at the point of separation.

The problem with shrinkable electrode blocks is that the adjustment of the power per unit area after reducing the contact surface of the electrode block must be done manually and depends on the experience of the operator.

Therefore, the object of the present invention is to provide improved power correction per unit area also in reducible electrode assemblies.

To solve this problem, according to the invention, a device for plasma treatment of the kind mentioned at the beginning is proposed, characterized in that the control unit has a device for determining the size of the contact surface to be corrected and a control device for adjusting the power supplied to said at least one electrode, depending on the specified size of the contact surface.

The problem is further solved by means of a method of the kind mentioned at the outset, which is characterized in that the size of the reduced surface is determined by means of a control unit, and accordingly the power supplied to said at least one electrode is adjusted depending on the set size of the contact surface. .

According to the invention, it is thus provided to mechanically reduce the contact surface of the electrode block in order to adjust to the dimensions of the surface to be treated and then provide for the adjustment of the electric power supplied by the control unit to the electrode block, according to this reduced surface. To this end, said control unit is provided with a device for determining the size of the contact surface to be corrected and with a control device for adjusting the corresponding power supplied to said at least one electrode, so that the adjustment of the electric power required to obtain plasma, under the now existing contact surface of the electrode block possible in such a way that the plasma power per unit surface for all installed contact surfaces will be approximately the same. In this way, it can be prevented that an effective plasma cannot be obtained due to insufficient electrical power, or that damage occurs on the surface to be treated due to too powerful plasma, which, in particular, could lead to painful consequences on body surfaces.

Said control unit is preferably designed and equipped in such a way that the determination of the size of the contact surface of the electrode unit takes place after the electrode unit is connected to the control unit, in particular connected to the control unit in an operable form.

Determination of the size of the contact surface can be carried out in several ways, and the contact surface is always understood as the effective contact surface of the electrode block.

If the flat electrode block is made in the form of a strip with at least one electrode of a given width extending in the longitudinal direction between the first end and the second end, so that the length of the strip forms the size of the contact surface, then, according to the invention, said device for determining the size of the contact surface can be a detecting device for the length of the strip. In this case, the control unit can output an electrical test signal to the electrode, which can be input into the electrode as losslessly as possible at the first end and reflected at the other end, the second end. Thus, the corresponding reflected wave was superimposed on the wave introduced at a given frequency on the electrode. By changing the frequency of the test signal, it is now possible to determine when the injected signal will attenuate due to the superposition of the reflected signal on it. With a suitably large output wavelength, increasing the frequency would lead to a shortening of the wavelength, so that the first attenuation of the signal is a measure of the length of the strip forming the electrode block, if the frequency and, accordingly, the wavelength are known, since this attenuation occurs for the first time when the band length corresponds to a quarter of the wavelength (?/4). Thus, the control device requires a frequency generator, with which the frequency, respectively, the wavelength can be continuously adjusted. Further, a detector is also needed for the electrical signal in order to detect said (first) attenuation. The control block must read the indicated frequency or the indicated wavelength at which the attenuation occurred. According to the set length of the strip and thus the set size of the contact surface, the electrical parameters can be adjusted in order to achieve a maximum constant power per unit area for plasma formation.

Alternatively, starting from the control device, it is possible to fix the reduced electrode block with the help of a camera and, by appropriate interpretation of the images, determine the size of the reduced electrode block, and then set the power supplied by the control block.

If the electrode block consists of a plurality of sections with electrodes of the same design, between which there are lines of a given separation, so that the reduction of the contact surface occurs by separating one or more sections, then these sections can be provided with different coding, which can be read by the control unit using a reading detector . By recognizing the coding of that portion of the remaining electrode block from which one or more portions have been separated, then the size of the remaining electrode block can be directly determined and applied to adjust the electrode block. At the same time, said coding can be formed in any form, for example, mechanically - in the form of elevations or recesses, optically - in the form of a bar code, QR code, etc., magnetically - with a permanent magnet, or electronically. For electronic education, it is possible, in particular, to use transponders in these areas.

The present invention will be discussed in more detail below for a better understanding with reference to the exemplary embodiments shown in the drawings, which do not limit the scope of the claims in any way. The drawings show the following.

Fig. 1 is a perspective view of an electrode block formed from several identical sections with a connected housing containing a power source and a control unit,

Fig. 2 is the image of FIG. 1 with top case removed,

Fig. 3 is a plan view of the device of FIG. 2,

Fig. 4 top view of FIG. 3 devices in which an (optionally) shortened electrode block is connected to the body,

Fig. 5 is the perspective view of FIG. 2 for short electrode block,

Fig. 6 is a perspective view similar to FIG. 2 for the second embodiment, in which the sections of the electrode block have different mechanical coding,

Fig. 7 is a plan view of the device of FIG. 6,

Fig. 8 is a section along the line A-A in FIG. 7,

Fig. 9 is a perspective view similar to FIG. 5 for the second embodiment,

Fig. 10 is a plan view of the housing to which the electrode block is connected, formed from a spirally wound strip,

Fig. 11 is a side view of the device of FIG. 10,

Fig. 12 is a horizontal section through the housing along line B-B in FIG. eleven,

Fig. 13 is a vertical section of the housing and the electrode unit along the line A-A in FIG. 10.

A first embodiment of the plasma treatment apparatus according to the invention is shown in FIG. 1 - Fig. 5. An electrode block 4 is connected to the closed body 1, consisting of the lower part 2 of the body and the upper part 3 of the body, with the creation of an electrical contact. The electrode block 4 in the exemplary embodiment shown consists essentially of 6 identical sections 5, which are connected to each other along lines 6 of a predetermined separation. Sections 5 are flat sections, which on their upper side and lower side are formed by a dielectric 7, which in the embodiment shown has through holes 8. Sections 5 are exemplarily rectangular and on their longitudinal edges 9, which are perpendicular to the lines 6 of the desired separation, have flat adhesive strips 10 with which the electrode unit 4 can be attached to the surface to be treated, such as the skin of a human or animal body. The section 5 furthest from the body 1 is provided with an additional adhesive strip 10a running parallel to the lines 6 of the desired separation.

On FIG. 2 shows the housing 1 with the upper housing part 3 removed so that only the lower housing part is visible. In the housing 1 there is a control unit 11, which, through two high-voltage coils 12a, 12b, along the corresponding lines 13a, 13b, supplies two high-voltage signals to the electrode unit 4. The housing 1 also contains a detection device 14, with which an electrical signal can be applied to at least one of the lines 13a, 13b, as long as a high voltage signal is not yet conducted along these lines 13a, 13b.

On FIG. 2 next to the vertical side walls of the lower housing part 2, screw fasteners 15 can be seen with which the upper housing part 3 can be screwed to the lower housing part.

On FIG. 3 shows a top view of the structure in the lower part 2 of the housing and a horizontal section of the electrode block 4. A power source 16 can be connected to the housing 1, which supplies voltage to the control unit 11 in the housing 1. The microcontroller 17 is located in the control unit, which generates high-frequency control pulses that in the signal conditioning stage 18 are prepared in such a way that the outputs of both high-voltage coils 12a, 12b are given a series of high-frequency pulses, each of which has high-frequency oscillations, strongly damped in amplitude. The pulse repetition frequency usually lies between 1 kHz and 20 MHz. On FIG. 3 schematically shows that the output signals of the high voltage coils 12a, 12b, which are the secondary coils of a high voltage transformer, are respectively applied to one of the partial electrodes 19a, 19b of the electrode 19. These partial electrodes extend mirror-symmetrically with respect to the center line 20 of the sections 5 in the longitudinal direction of the electrode block. 4. The width of the partial electrodes 19a, 19b in the region of the predetermined separation line 6 is reduced stepwise. The partial electrodes 19a, 19b are provided with (here circular) holes 21, which are coaxial with the through holes 8 of the dielectric, however, have a larger diameter, so that these through holes 8 of the dielectric pass through the electrode 19 through and form a passage channel, which, along the height of the electrode 19, has formed by dielectric 7 wall. It is thus ensured that a fluid, in particular a liquid, can pass through these through holes without the liquid coming into contact with the electrode 19. Said electrode unit 4 is thus also suitable for application to a wound on human or animal skin. , and through these through holes can be discharged wound discharge.

Said electrode 19, which - as shown - can be formed by two or more partial electrodes 19a, 19b, is embedded in the dielectric 7 and is therefore shielded against contact, in particular with respect to the surface to be treated. Applying a high voltage RF potential to the electrode results in a high voltage field between the electrode 19 and the surface to be treated, which acts as a counter electrode (ground electrode). Both partial electrodes 19a and 19b are supplied with mirror-symmetric high voltage signals, which result in the sum signal being zero. This is achieved, for example, by the fact that both high-voltage coils 12a, 12b are controlled by identical control signals, but wound in opposite directions, so that signals of opposite polarity are generated at the output of both coils. In the area of partial electrodes, this would lead to an increase in the plasma field, while these fields are already compensated for at some distance, so that the harmful effect of high-frequency signals on the environment is greatly reduced.

It goes without saying that the implementation of the electrode 19 with two partial electrodes is in many cases preferred, however, is not necessary for the implementation of the present invention. It can also be implemented with one solid electrode 19.

It is also possible that the partial electrodes are controlled such that one partial electrode receives a high frequency AC voltage signal while the other electrode forms a counter electrode as a ground electrode. This embodiment is useful if the surface to be treated is not suitable as a counter electrode due to the material of the body having this surface, for example because it does not have the required conductivity. In this case, the partial electrodes do not have to be located next to each other, as shown in FIG. 3, but according to the already known scheme, they can also be stacked on top of each other so that a dielectric layer is placed between the two electrodes.

On FIG. 4 shows a construction in which the electrode block 4 is formed by only two sections 5 connected to each other, so that this electrode block 4 forms with respect to the electrode block 4 of FIG. 3 a significantly smaller contact surface to the (not shown) surface to be treated.

In order for the control unit not to supply the smaller electrode unit 4 of FIG. 4 with the same electric power as the large electrode block 4 of FIG. 3, the size of the contact surface is determined by the detection device 14 when this electrode unit 4 is connected to the control unit 11 in the housing 1. To do this, the detection device 14 applies an electrical signal to at least one of the partial electrodes 19a, 19b. This electrical signal of the detection device 14 at the free end of the partial electrodes 19a, 19b, i. e. at the end remote portion 5 is reflected, so that a superposition of the sent signal on the reflected signal can occur. The detecting device 14 can be configured to send out a continuous harmonic electrical signal whose frequency (wavelength) can be adjusted. This frequency can be adjusted so that a first attenuation of the sum signal can be detected. This attenuation occurs if the length of the electrode block 4 corresponds to a quarter wavelength. Thus, according to the set wavelength, at which the first attenuation of the total signal occurs, it is possible to determine the length of the electrode block 4. Since the presented electrode block 4 has a length proportional to the contact surface, using the microcontroller 17 as a control device of the control unit 11, you can adjust the amplitude control signal - and thereby set the electrical power available to the plasma field depending on the size of the contact surface.

Accordingly, the electrode block 4 of FIG. 4 is supplied with a different electrical power than the electrode unit 4 of FIG. 3. Construction for the small electrode block 4 of FIG. 4 is shown in FIG. 5 in perspective.

The person skilled in the art will appreciate that the illustrated external power supply 16 is optional. It is possible to install an autonomous power supply in the housing, which is powered by rechargeable or non-rechargeable batteries, and high-frequency AC voltage signals are generated in a known manner by a vibration transducer or an oscillatory circuit with a pulse control. Further, high voltage signals can already be applied to the control unit 11, for which, however, the use of lines with high voltage protection is required.

In the second embodiment of the present invention, which is shown in FIG. 6 - Fig. 9, the electrode block 40 again consists of essentially the same sections 50, which can be constructed in the same way as the sections 5 according to the first embodiment. The only difference is that said sections 50 each have a correspondingly different mechanical coding 22 on their leading edge adjacent to the respective line 6 of the given separation. The sensing arms 23 in the housing 1 interact with these mechanical coding elements 22. The position of the sensing arms is recognized by the detection device 14, which can thus determine which section 50 is in contact with the control unit 11 in the housing 1. The electrode unit 40 was shortened by separating at least at least one section 50 at that end of the electrode block 4, which is opposite the section 50 with the end strip 10a for gluing. Thus, by identifying the portion 50 contacted by the control unit 11 of the body 1, the length of the remaining electrode unit 40 can be determined. Accordingly, said control unit 11 controls the electrical power that is supplied to the electrode 19. In this embodiment, said electrode 19 is the only electrode. It goes without saying that in this embodiment, too, the electrode 19 can be formed from two or more partial electrodes 19a, 19b.

The feeler arms 23 interacting with the mechanical coding elements 22, as shown in FIG. 7 - Fig. 9 are two-arm levers, which are installed pivotally on a common axis and have a downwardly curved probe 25 directed towards the electrode block 40. With the help of a pressure spring 26 acting from below on the other side of the axis 24, the probe 25 is pressed down to the surface of the section 50 inserted into the housing 1 Only the sensing arm 23 or the sensing arms 23, for which there is a mechanical coding 22 in section 50, is lifted on the probe 25, as shown in FIG. 8 and FIG. 9.

Comparison Fig. 6 and FIG. 9 shows that on the long electrode block 4 of FIG. 6 is encoded so that only the one on the right in FIG. 6 sensing lever 23, while for a short electrode block, the penultimate one in FIG. 6 section 50 encoding with two heights for both right sensing arms 23, if the electrode block 4 consists of only the last two sections 50.

The lifting of the probes 25 - and thus the change in the position of the probe arm 23 - can be detected in the usual way, for example by closing the contacts on the lever arm remote from the probe 25. It is also possible to detect using the photoelectric sensor 27 as shown in FIG. 8. If there is only one photoelectric sensor, then the interruption of the light beam by one of the levers may also indicate that the control unit 11 of the housing 1 has been contacted with the electrode unit 4 in order to perform sizing at this point in time, before the signal high voltage will be directed to electrode 19.

It is essential within the scope of the present invention to determine the size of the electrode block 4 when the electrode block 4 is in contact with the control block 11 on the housing 1 or immediately after this contact.

In the third one, shown in Fig. 10 - Fig. 13 of the embodiment of the present invention, the electrode block 4 is in the form of a spirally twisted strip, which can be cut off at any point in order to reduce the usable contact surface of the electrode block 4. there can make contact with the switch button 28, for example, due to the fact that the metal blade contact of the switch button cuts through the dielectric 7 and creates a conductive contact with the electrode 19 inside the dielectric 7. The switch button can be fixed using the slider 29, so that a protected from high-voltage breakdown connection. The housing 1 can be provided with a control unit 11 in the same manner as the housing 1 in the above-described embodiments.

It goes without saying that the exemplary embodiment of the electrode block 4 for the third embodiment is not a necessary condition, since other forms of electrodes are also possible as an electrode block, for example with a linearly straight strip.

As a detecting device 14, a camera 30 is provided in the housing 1, which is directed to the surface of the electrode block 4, so that the size of the connected electrode block 4 can be determined by means of image interpretation. It is also essential that the size of the electrode block 4 is determined after how contact with the control unit 11 in the housing 1 took place.

In all embodiments, the electrode block 4 on its contact surface on the side of the surface to be treated can be provided with spacer protrusions 31 formed in the dielectric 7, with the help of which, when adjacent to the surface to be treated, gas spaces are left in which a dielectric barrier discharge plasma can form. On FIG. 12 and FIG. 13 shows the placement of the chamber 30 above the top side of the electrode block 4.

It can be understood without problems that the embodiments shown can be combined in terms of the shape of the electrode block 4 used and in terms of the detection devices 14 used, and that no restrictions are imposed on said combinations. The same applies to the execution of the housing 1 and to the type of contacts between the electrode unit 4 and the control unit 11 in the housing 1, which can be implemented in any conventional way.

List of reference symbols

1 building

2 lower body

3 top case

4 electrode block

5 plots

6 lines of predetermined separation

7 dielectric

8 through holes

9 longitudinal edges

10, 10a adhesive strips

11 control unit

12a, 12b high voltage coils

13a, 13b lines

14 detecting devices

15 screw fixings

16 voltage source

17 microcontroller

18 signal conditioning stage

19a, 19b partial electrodes

20 middle line

21 holes

22 mechanical coding

23 feeler arm

24 axis

25 probe

26 pressure spring

27 photoelectric sensor

28 key switch

29 slider

30 camera

31 spacer tabs

Claims (10)

1. A device for plasma treatment for conducting a plasma dielectric barrier discharge on the surface to be treated, containing a flat electrode block (4) having a processing side, and a control block (11), which is on at least one electrode (19) of the electrode block (4 ) supplies a high voltage alternating potential for the power required to produce a plasma between said at least one electrode (19) and a counter electrode forming a reference potential, wherein said at least one electrode (19) receiving said high voltage alternating potential is at least on the processing side, it is shielded with a flat dielectric (7), and the flat electrode block is configured to mechanically reduce the size of its contact surface to the surface to be processed to adjust for the size of the surface to be processed, characterized in that the control unit (11) contains a device (14) for determining the size of the contact surface to be corrected and a control device for regulating the power supplied to the said at least one electrode (19), depending on the set size of the contact surface. 2. A device for plasma treatment according to claim 1, characterized in that the flat electrode block (4) is made in the form of a strip with at least one electrode of a given width extending in the longitudinal direction between the first end and the second end, and the length of the strip determines the size of the surface fit, and the specified device for determining the size of the fit surface contains a detecting device (14) to determine the length of the strip. 3. Plasma treatment device according to claim 2, characterized in that the detection device (14) is designed to determine the length of the strip by means of an electrical test signal transmitted to said at least one electrode. 4. Plasma treatment device according to claim 3, characterized in that the electrode (19) is configured to reflect at the second end the electrical test signal transmitted to the first end. 5. Plasma processing device according to claim 4, characterized in that the detecting device (14) contains a frequency generator designed to generate an electrical test signal, and a control device for continuously adjusting the frequency of the test signal, and a detecting device for determining the amplitude of the test signal. 6. Plasma treatment device according to claim 5, characterized in that the frequency generator is designed to generate an electrical test signal in the form of a series of harmonic waves. 7. Plasma treatment device according to claim 1, characterized in that the control unit (11) has a chamber system with at least one chamber (30) and an information processing device for determining the length and/or area of the electrode unit. 8. A device for plasma treatment according to claim 1, characterized in that the electrode block (4, 40) consists of a plurality of sections (5, 50) with electrodes of the same design, between which there are lines (6) of a given separation, so that the reduction of the surface adhesion occurs by separating one or more sections (5, 50). 9. The device for plasma treatment according to claim 8, characterized in that the sections (50) carry different codings (22), for which the control unit contains a reading detector, and the connection of the electrode unit (4) with the control unit (11) is provided in the section (50) from which one or more sections have been separated. 10. A method for adjusting the size of the contact surface of the flat electrode unit (4) of the device for plasma treatment for conducting a plasma dielectric barrier discharge on the surface to be treated to the dimensions of the surface to be treated, with at least one electrode (19) of the electrode unit ( 4) a high-voltage alternating potential is supplied by the control unit (11) for the power necessary to obtain plasma between the said at least one electrode (19) and the counter-electrode forming the reference potential, and the said at least one electrode (19) receiving the said high-voltage alternating the potential, at least on the processing side, is shielded by a flat dielectric (7), and the contact surface of the electrode block (4) is mechanically reduced to adjust for the size of the surface to be processed, characterized in that the size of the mechanically reduced surface is determined by means of the control block (11). contact and, in accordance with this, regulate the power supplied to the said at least one electrode (19), depending on the set size of the contact surface.

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