DE19926084B4 - Suction device and device containing a suction device - Google Patents

Abstract

suction for sucking air from the surface of an object (1), for example a workpiece to be cleaned or a sample table, with a suction tube (65), which is the object (1) in the plane of the surface Completely surrounds and along his Inner circumference gas passage openings characterized in that the suction tube (65) has a kidney-shaped cross section with a recess along its outer periphery having.

Description

The present invention relates to a suction device and to a device for the treatment, in particular for the cleaning of surfaces by means of a CO ₂ snow jet. Such suction devices and devices are used in the optical industry, medical technology, the pharmaceutical industry, the painting technique, the micro and precision engineering for the treatment of surfaces, including the treatment of soft surface coatings, gels and the like. The basis of this treatment or cleaning process is the cleaning by means of CO ₂ -iscrystals. The method is also used for the dry local cleaning of particulate and cinematic impurity of structured and composed of elements of different materials surfaces to the submicron range.

The progressive miniaturization with simultaneous hybridization of assemblies requires a cleaning process that allows local cleaning of functional surfaces without contaminating adjacent areas by cross-contamination. The use of conventional cleaning methods, such as ultrasound or the use of aggressive chemicals is due to material incompatibilities only rarely possible. Blasting with CO ₂ particles is an interesting alternative here.

CO ₂ ice cleaning is a dry, deep-cold, residue-free blasting process with a wide range of applications. In principle, dry ice blasting can be divided into two different processes - cleaning with airborne dry ice pellets and cleaning with CO ₂ snow.

The Blasting with dry ice pellets is since 1987 for paint stripping and Cleaning of aircraft components and aircraft used. Especially because of the property of dry ice during the cleaning process to sublimate and thus no contaminated detergent too left, parts could be cleaned in the installed state and cleaning costs on aircraft are reduced by up to 50%.

today The blasting with dry ice pellets has already been in many areas such as B. the Entlackung of aircraft, the facade cleaning or the Eliminate gross contamination on machines enforced. His Strength the residue-free cleaning It plays especially in the assembly cleaning already installed Plants off.

The cleaning effect is fundamentally based on three mechanisms. On the one hand, when the CO ₂ crystals impinge on the surface, the contamination or the coating on the surface is strongly supercooled, as a result of which they shrink and become brittle. Due to the different thermal expansion of the base material and contamination or coating stresses arise so that the connection between the pollution and the base material is loosened or dissolved. Furthermore, the embrittled impurity is further released and mechanically removed by the impulse transmitted by the CO ₂ pellets. Finally, the material removed by the dry ice pellets is held in suspension by the sublimated CO ₂ and possibly further supporting gas and transported away from the cleaning zone.

The Blasting method using dry ice pellets is for example in "edged or round, Metal salts and carbon dioxide pellets are exotic compounds in the Blasting technique "from Reinhold Schäfer in Machine Market Würzburg 98 (1992).

A disadvantage of the blasting technique using dry ice pellets is that the cooling during and after the cleaning carried out a recontamination of the surface by deposition previously contained in the air and remaining during the drying of the CO ₂ ice film remaining substances. In particular, the ambient moisture precipitates on the cooled surface following the radiation, so that the object to be cleaned becomes moist.

Alternatively, instead of dry ice pellets, dry ice crystals can also be used as blasting agents. In this case, a jet of CO ₂ snow is generated, which is blasted at high speed onto the surface to be cleaned.

In order to prevent the held by resublimation the humidity during the cleaning icing of the surface through which a further cleaning action of the CO ₂ snow crystals difficult to be prevented, two methods are known in the prior art. On the one hand, a heated plate is used as a base for the items to be cleaned in order to reheat the items as quickly as possible after the dry ice jet has been swept over. The effectiveness of this method as an individual measure is partially greatly impaired by the material, the geometry and the size of the cleaning material or not at all. Alternatively, the CO ₂ snow jet may be surrounded by a sheath jet that is heated. As a result, when passing over a surface through the CO ₂ jet, the surface is immediately replaced by the support beam warms, so that the condensation of the humidity is reduced or prevented. However, this method causes an undesirable heating of the CO ₂ ice jet by the warm support beam, so that the effectiveness of the blasting process is impaired. Such a method is in the US 5,725,154 A described.

A disadvantage of the blasting method using CO ₂ -snow crystals is that they have a much lower pulse than the dry ice pellets with a diameter of several millimeters, so that the cleaning effect compared to dry ice pellets is considerably lower.

In the US 5 725 154 A It is proposed to generate an inductive magnetic field to compensate for the charging of the flowing liquid CO ₂ . The ionization due to charge separation during the expansion of the CO ₂ and the crystallization of the CO ₂ snow is not compensated.

The problem with all these prior art processes is the cross-contamination of surface areas due to the erosion produced elsewhere by the CO ₂ ice jet.

The US 4,594,747 discloses a device by means of which, for example, animal hair can be sucked from a table. For this purpose, the table is provided with a circumferential shelf, which tapers funnel-shaped on a suction pump below the table. In this way, the pet hairs are sucked off the side of the table edge down.

The DE 28 31 961 A1 relates to a parts washing device with a tub, are washed in the parts to be cleaned by means of solvent-based detergent. The trough has along its edge a U- or C-shaped channel to prevent vapors that are heavier than air from overflowing over the edge of the tub.

task The present invention is a suction device and a To provide this containing jet device, with the surfaces easy and reliable treated without recondensation of water or cross-contamination, in particular can be radiated.

These The object is achieved by the suction device according to claim 1 and the Device according to claim 14 solved. Advantageous developments of the jet tool according to the invention and the Device according to the invention become dependent claims given. According to the invention can suction device according to the invention and the device according to the invention as in the claims 42 to 44 can be used.

By the suction device according to the invention is advantageously the radiated, sublimated CO ₂ and the high-volume support or pressure jet, which flows without further deflection from the sample table, collected and then sucked from there, whereby a cross-contamination of other surface areas is reliably minimized. The suction device according to the invention also does not generate any whirl or the like outside of the suction device itself, so that the laminar flow of the inflowing air is not disturbed and its purity is reliably maintained.

All in all results in a very high efficiency with short treatment time using the device according to the invention and the suction device according to the invention. Further advantageous properties are a simpler, more compact Unit design, a high device safety, low Plants, - operating and maintenance costs, a high degree of automation, Good reproducibility of the cleaning result and easy handling the device and the suction device.

The development according to the invention of the blasting device with the blasting tool according to the invention achieves the following improvements:
On the one hand, a very high jet velocity is achieved by using a Laval nozzle, so that the very small ice crystals can be shot through the forming on the surface to be cleaned gas cushion. Furthermore, the static charge of the carbon dioxide solid snow, which is a problem in the cleaning of electronic components, is canceled by the ionization device. Furthermore, a laminar flow is generated in the cleaning chamber through the nozzle and by the inventive device of the cleaning device, so that no dirt nests are formed within the cleaning system. In particular, the beam diameter is extremely low, so that it is suitable for use in microsystems and precision engineering and the system can be used flexibly in the production of microsystems. The blasting tool is fully movable and the cleaning process can be easily automated. Overall, a high efficiency results in a short cleaning time.

Overall, a fast and icing-free cleaning of components during production is possible by eliminating complicated and expensive cleaning preparations by the device according to the invention. With the dry ice blasting process according to the invention, a plurality of Materials should be cleaned, provided that they withstand the short-term temperature shock. There are only minor limitations to the structures involved, as dry ice blasting, as with all blasting processes, is a line of sight process. Therefore, only surfaces can be cleaned, which lie in the beam direction. The cleaning of blind undercuts is not possible or only very limited. The same applies to depressions with a relatively large aspect ratio, which fill relatively quickly with sublimed CO ₂ and thus impede or even prevent the further penetration of the ice crystals.

in the The following will be an example of a suction device according to the invention and a Device according to the invention described. It will be in all Figures like parts with the same reference numerals.

It demonstrate

1 the blasting method according to the invention;

2 a device according to the invention;

3 an extraction device according to the invention;

4 a section through the suction device according to the invention 3 ;

5 an inventive blasting tool;

6 a cleaning result according to the method of the invention; and

7 a further cleaning result according to the inventive method.

1 schematically shows the inventive method. A surface of an object 1 for example, a sample table is filled with CO ₂ ice crystals (CO ₂ snow) 3 from a spray nozzle 2 irradiated. The CO ₂ snow forms a CO ₂ jet 5 that a pollution 4 from the surface of the object 1 radiates. There are two mechanisms of action. A describes a mechanism of action in which a CO ₂ crystal 3 on the surface of the object 1 impinges and thereby the contamination 4 forcing off. With b another mechanism is described, in which the CO ₂ snow crystal on the surface of the object 1 hits and sublimates there. In this sublimation, the gas pressure causes contamination 4 from the surface of the object 1 dissolved and is taken from the effluent CO ₂ .

2 shows an inventive device for treating, in particular for blasting surfaces.

This device according to the invention has a cleaning chamber 36 in which a sample table 1 and a blasting tool 2 for producing a CO ₂ snow jet 5 are arranged and are surrounded by laminar flowing air. The usually perpendicular to the sample carrier 1 aligned gas jet 5 from the blasting tool 2 is used on the mostly flat cleaning objects or on the sample table 1 itself deflected by 90 ° and flows radially from the point of impact and parallel to the sample table 1 from. Due to the high flow velocity and the resulting gas volume, it is not possible to suck off the loosened material locally at the site of action. The extraction of the process gases is therefore outside the sample table 1 by means of the flow trap 21 facing the side of the sample table 1 is arranged in the plane of its surface and the sample table completely surrounding. This flow trap 21 that starts as surface flow 35 effluent CO ₂ , that of the CO ₂ snow jet 5 on the surface of the sample table 1 is generated laterally.

The sample table 1 is movable in all three dimensions, via a heater 22 heated and is from below via a valve 24 and a vacuum connection 23 connected to a vacuum line. The sample table 1 consists of a metallic perforated plate, so that by means of this negative pressure to be radiated objects on the surface of the sample table 1 can be fixed. There is also a controller 25 for the heating 22 of the sample table 1 provided to bring it to a constant temperature.

In the sample chamber becomes a laminar flow 6 generated along the walls 36 the cleaning chamber and in the direction of the CO ₂ snow jet 5 flows.

The jet tool 2 is over a cooler 26 , a filter 27 and a high pressure valve 28 liquid CO ₂ from a CO ₂ tank 34 fed. In the same way, the blasting device 2 via a fitting with pressure reducer 32 , a high pressure valve 30 and another valve 31 gaseous N ₂ from a N ₂ tank 33 fed. The two high pressure valves 28 and 30 are connected to a controller 29 connected.

• 1. Eine mit Reinstluft durchströmte Reinigungskammer 36 (z.B. Reinheitsklasse 1 gemäß VDI 2083 Blatt 1, Strömungsgeschwindigkeit 0,4 m/s),
• 2. ein Strahlwerkzeug 2 mit einer Beschleunigungs- und Mischdüse sowie einer Ionisierungseinheit (nicht gezeigt),
• 3. der Absaugvorrichtung 21,
• 4. einer Aufbereitungsanlage (nicht gezeigt) für das von der Absaugvorrichtung 21 abgesogene Gas, und
• 5. einem beheizten Probentisch 1.

Thus, the device according to the invention described in the core consists of the following components:

• 1. A clean air flow through with clean air chamber 36 (eg purity class 1 according to VDI 2083 Part 1, flow rate 0.4 m / s),
• 2. a jet tool 2 with an accelerating and mixing nozzle and an ionizing unit (not shown),
• 3. the suction device 21 .
• 4. a treatment plant (not shown) for that of the suction device 21 sucked gas, and
• 5. a heated sample table 1 ,

This device according to the invention generates a low-turbulence clean air flow in the cleaning chamber 36 , which is directed so that the jet tool 2 in front of the sample table 1 lies and the sample table 1 is flowed perpendicular bouncing. In combination with the suction device 21 Therefore, an uncontrollable contamination from the air due to the injection effect of the cleaning jet is avoided. At the same time prevents dirt from forming in the area of the entire system with time.

The jet tool 2 consists essentially of two nozzles integrated into one another: on the one hand, a capillary as the first nozzle, through which the carbon dioxide liquefied under high pressure is passed. At the flared end of the capillary liquid carbon dioxide exits, with about 55% of the mass evaporated by expansion and about 45% solidifies by resublimation into small crystals, the CO ₂ ice snow. The amount of effluent CO ₂ can be adjusted by variation and the capillary diameter.

On the other hand, the jet tool 2 a second nozzle concentrically enclosing the first nozzle and the capillary. This second nozzle is a Laval nozzle which discharges ultrapure, dry compressed gas (N ₂ ) at room temperature. By this compressed gas on the one hand, the dry ice snow beam is supported and further bundled and accelerated to a parallel beam.

This pressure or support beam can be started or terminated with a time delay to the CO ₂ snow jet, so that when switching on the CO ₂ snow jet after the start of the compressed gas jet, the ambient air is kept away from the cleaning point. Thus, the condensation of humidity at the cooled by the cleaning jet cleaning point is successively prevented. For the same purpose, the support beam can be switched off only after the CO ₂ snow jet.

Of the support beam from dry compressed gas leads furthermore, that the Substrate surface after the cleaning is heated quickly at the cleaning point.

The extraction of the material detached from the dry ice jet directly at the point of action, is not possible due to the high flow rate and the resulting gas volume with a conventional suction device. Therefore, a suction device according to the invention 21 used.

3 shows a cross section through the plane of the sample table 1 , The sample table 1 is completely from a suction pipe 65 the suction device 21 in the level of the sample table 1 surround. The usually perpendicular to the sample carrier aligned gas jet 5 is deflected by 90 ° on the mostly flat cleaning objects or on the sample table itself and flows radially from the point of impact on the surface of the object or the sample table as a laminar flow 35 from. The extraction of the process gases takes place in the suction device according to the invention 21 therefore only outside the sample table. As in 4 can be seen, the suction tube points 65 a kidney-shaped cross-section with indentations in the plane of the sample table 1 on. On the side of the sample table 1 this indentation is open as a gas inlet opening. The from the sample table 1 outgoing gas 35 consequently hits the inner wall of the suction ring 65 and will, supported by the center kink 66 due to the kidney-shaped constriction in the plane of the sample table 1 , deflected upwards or downwards. Due to the geometry of this flow trap 21 This is done at high speed from the sample stage 1 outgoing process gas 35 (Compressed gas, CO ₂ gas, abraded particles 4) in one to the corners of the suction ring 65 flowing swirl flow 63 transferred. In the corners of the suction ring 65 There are fans 61 that with the suction ring 65 via suction openings 64 keep in touch. These fans generate a suction volume flow through a suction channel 60 , which supports the flow of this jet flow and prevents backflow to the sample carrier.

The openings 64 between the suction ring 65 and the suction channel 60 are located above and below the middle bend 66 so that the formed vertebrae 63 be sucked off.

The extraction volume of the fans 61 is via a speed control constantly the sum of laminar supply air gas flow 6 (please refer 2 ) and purge gas stream 5 customized. The supply air flow is determined by the free cross-sectional area of the suction ring 65 and the supply air velocity (velocity of the purest gas stream 6 ). The calculation of the cleaning gas flow 5 takes place essentially on the basis of the diameter of the capillary 42 the CO ₂ supply, the geometry of the Laval nozzle 51 and the form of the pressure / support gas in a conventional manner.

The extracted gas is then removed by the fans 61 to a process exhaust system 62 blown, where the extracted air can be cleaned, processed and / or reused.

5 shows a cross section through an inventive blasting tool, which will now be described in more detail.

The jet tool consists essentially of two nozzles integrated into one another: a capillary 42 through which the liquefied under high pressure CO ₂ is passed and at the conically enlarged end 49 the CO ₂ expands. This produces a mixture of gas and dry ice snow. The proportion of snow is approximately 45% of the total mass flowing out. The amount of effluent CO ₂ can be varied by varying the diameter of the capillary 42 be set.

Furthermore, the capillary 42 Concentric of a special Laval nozzle 51 enclosed, from the over a line 56 supplied dry compressed gas (pure air or pure nitrogen) supersonic flows out. This compressed gas jet bundles the steel from dry ice snow into a parallel jet and accelerates it. In addition, the ambient air is kept away from the cleaning point by this pressurized gas support jet and the substrate surface is heated again quickly after cleaning. The condensation of humidity is thus successfully prevented.

The Laval nozzle 51 is determined by the outer contour of a nozzle needle 45 holding the capillary 42 contains and through the inner contour of a nozzle head 46 educated. The Laval nozzle 51 can by changing the minimum cross section by moving the nozzle needle 45 relative to the nozzle head 46 finely adjusted and optimally adjusted. The fixation is then carried out by placing suitable spacers between one on the nozzle needle 45 arranged flange 43 and the nozzle head 46 ,

Both the liquid CO ₂ and the compressed gas is via the nozzle needle 45 fed. The compressed gas then flows to calm over four inlet side of the Laval nozzle 51 arranged star-shaped holes in the antechamber of the Laval nozzle 51 , From the Lavaldüse the compressed gas flows with supersonic, twist-free and symmetrical.

The CO ₂ gets over the capillary 42 fed into the channel of the nozzle needle 45 to be led. A stopper 48 at the bottom of the nozzle needle 45 centers the capillary 42 and at the same time seals the compressed gas channel downwards. At the upper end of the compressed gas channel through the CO _{2 line} 40 and their screwing 41 locked.

Because the CO ₂ due to pressure change within the geometry of the Laval nozzle 51 would change the state of matter, the two nozzles, the Laval nozzle 41 and those at the end of the capillary 42 trained snow-nozzle 49 arranged so that the supporting gas is added to the finished dry ice snow jet. Otherwise, the function of the jet tool would not be guaranteed.

The entire system is sealed by two seals, namely a package 44 with flange 43 and a thin metal foil between the nozzle head 46 and a connection plate 55 ,

At the end of the nozzle is a metal ring 50 with three ionization peaks through an insulator 47 Isolated, attached via a high voltage cable 53 connected to a controllable ionizer. About the ionization peaks of the metal ring 50 becomes the highly negative charge of the CO ₂ jet upon crystallization of CO ₂ at the exit of the capillary 42 compensated by continuous deionization.

Furthermore, the capillary 42 grounded by means of a ground cable, so that the charge separation in the peripheral layer of flowing through the capillary liquid CO _{2 is} raised in mind.

With This system has already been replaced by different parts from the microsystem or precision engineering successfully cleaned. These include, for example contact surfaces of micro switches, nozzle elements from the printing technology, on a ceramic carrier constructed microchips and Stamped parts for the construction of switching elements. Both particulate deposits were formed as well as biotic and / or abiotic coating such as fingerprints or thin Removed paint layers.

As a further advantageous embodiment, the CO ₂ supply is designed so that short CO ₂ beam bursts can be generated. These are much more effective compared to a continuous CO ₂ jet, since higher thermal stresses are generated here compared to the longer exposure time of the dry ice jet.

6 shows an example of a cleaning with the device according to the invention. Above are encrusted nozzles of an ink jet print head shown, which have been cleaned according to the invention. In the lower part of the figure, a microchip is shown on a ceramic carrier with its scaling visible on the right side. On the left side, the cleaned area can be seen in this picture.

7 shows a lacquer layer which has been treated with the device according to the invention. The representation in 7 is 50 times larger. As can be seen, the paint layer is partly with the inventions have been removed according to the invention. Clearly, the cracking and the detachment from the base material can be seen.

Claims (44)

Suction device for extracting air from the surface of an object ( 1 ), for example, a workpiece to be cleaned or a sample table, with a suction tube ( 65 ) that the object ( 1 ) completely surrounds in the plane of the surface and along its inner periphery gas passage openings, characterized in that the suction tube ( 65 ) has a kidney-shaped cross section with a recess along its outer periphery. Suction device according to the preceding claim, characterized in that the suction tube ( 65 ) is opened along the indentation along its inner circumference as a gas passage opening. Suction device according to one of the two preceding claims, characterized in that along the outer circumference of the suction tube ( 65 ) existing indentation formed as a pointed converging, inwardly facing edge formed center bend ( 66 ) having. Suction device according to one of the preceding claims, characterized in that the cross section of the suction tube ( 65 ) is formed such that the extracted air within the tube along its cross-section vortex ( 63 ). Suction device according to one of the preceding claims, characterized in that the suction pipe ( 65 ) with at least one fan ( 61 ) for the extraction of air from the suction tube ( 65 ) connected is. Suction device according to the preceding claim, characterized in that the at least one fan ( 61 ) is adjustable in its speed. Suction device according to one of the two preceding claims, characterized in that the at least one fan ( 61 ) via openings ( 64 ) with the suction tube ( 65 ) connected to the top and / or bottom of the suction tube ( 65 ) are arranged. Suction device according to one of claims 5 to 7, characterized in that the at least one fan ( 61 ) via openings ( 64 ) with the suction tube ( 65 ), which are laterally of the middle bend ( 66 ) are arranged. Suction device according to one of the preceding claims, characterized in that the suction tube ( 65 ) is annular. Suction device according to one of claims 1 to 8, characterized in that the suction tube ( 65 ) is designed as a polygon. Suction device according to the preceding claim, characterized in that the suction tube ( 65 ) between each two adjacent corners arcuately in the direction of the object ( 1 ) is curved. Suction device according to one of the two preceding claims, characterized in that in each corner of the polygon a, preferably adjustable, fan ( 61 ) is arranged according to one of claims 6 to 9. Device for treatment, for example for cleaning, of a surface of an object ( 1 ), for example a workpiece or a sample table, characterized by blasting the surface with CO ₂ snow, a suction device for sucking off the gas flowing out of the surface and material removed from the surface according to one of the preceding claims. Device according to the preceding claim, characterized in that the suction device and the object ( 1 ) in a cleaning chamber ( 36 ) are arranged. Device according to the preceding claim, characterized in that the cleaning chamber ( 36 ) of pure air ( 6 ) is flowed through. Device according to one of the two preceding claims, characterized in that the cleaning chamber ( 36 ) of the purest air ( 6 ) turbulence, quasilaminar flows through. Device according to one of the two preceding claims, characterized in that the object ( 1 ) in the cleaning chamber ( 36 ) is arranged so that its surface of the purest air ( 6 ) has flowed perpendicular bouncing. Device according to one of claims 14 to 17, characterized in that the cleaning chamber ( 36 ) a sample table ( 1 ) for mounting a workpiece to be treated or cleaned. Device according to the preceding claim, characterized in that the sample table ( 1 ) is heated. Device after the previous one claim, characterized in that the sample table ( 1 ) is electrically heated. Device according to one of claims 18 to 20, characterized in that the sample table ( 1 ) has a flat metal plate for attachment of the workpiece to be treated or cleaned. Device according to the preceding claim, characterized in that the metal plate has a plurality of bores and a vacuum pump ( 23 ) is provided for applying a vacuum to the holes. Device according to one of claims 13 to 22, characterized that one Processing plant for aspirated and optionally contained therein particles provided is. Device according to one of claims 13 to 23, characterized by a jet device ( 2 ) for generating a jet of CO ₂ snow with a first nozzle ( 49 ) for generating a CO ₂ snow jet and a second nozzle ( 51 ) for generating a support or pressure jet, wherein the second nozzle ( 51 ) the first nozzle ( 49 ), and wherein the second nozzle ( 51 ) is a nozzle for generating a supersonic jet. Device according to the preceding claim, characterized in that the second nozzle ( 51 ) is a Laval nozzle. Device according to one of the two preceding claims, characterized in that the second nozzle ( 51 ) is designed so that it the jet of the first nozzle ( 49 ) bundles, preferably in parallel bundles, and / or accelerates. Device according to one of Claims 24 to 26, characterized in that the first nozzle ( 49 ) with a capillary ( 42 ) is connected as a supply line. Device according to the preceding claim, characterized in that the capillary ( 42 ) is electrically grounded. Device according to one of the two preceding claims, characterized in that the first nozzle ( 49 ) as a conical extension of the capillary ( 42 ) is trained. Device according to one of Claims 24 to 29, characterized in that the second nozzle ( 51 ) the first nozzle ( 49 ) concentrically encloses. Device according to one of claims 24 to 30, characterized in that the jet tool ( 2 ) a nozzle needle ( 45 ) and a surrounding nozzle head ( 46 ), wherein the first nozzle in the nozzle needle ( 45 ) is arranged. Device according to the preceding claim, characterized in that the second nozzle ( 51 ) as a gap between the nozzle needle ( 45 ) and nozzle head ( 46 ) is trained. Device according to the preceding claim, characterized in that the contour of the second nozzle ( 51 ) through the outer contour of the nozzle needle ( 45 ) and / or through the inner contour of the nozzle head ( 46 ) is trained. Device according to one of claims 31 to 33, characterized in that the nozzle needle ( 45 ) along the nozzle head ( 46 ) is displaceable. Device according to one of claims 31 to 34, characterized in that at the lower end of the nozzle needle ( 45 ) a device for storage and centering of the nozzle needle in the nozzle head ( 46 ) is arranged. Device according to one of Claims 24 to 35, characterized in that the second nozzle ( 51 ) has at its inlet a plurality of star-shaped bore for gas supply. Device according to one of claims 24 to 36, characterized in that in the jet direction behind the first nozzle ( 49 ) a device ( 50 ) is arranged for deionization of the CO ₂ snow jet. Device according to the preceding claim, characterized in that the device ( 50 ) for deionization one to the first nozzle ( 49 ) has concentric metal ring. Device according to the preceding claim, characterized characterized in that Metal ring at least one projecting into the beam area Ionisationsspitze having. Device according to one of Claims 37 to 39, characterized in that the device ( 50 ) for deionization via a high voltage cable ( 53 ) is connected to an ionizer. Device according to the preceding claim, characterized characterized in that Ionizer is adjustable. Use of a suction device and / or a device for the treatment, for example cleaning, of surfaces according to one of the preceding claims for cleaning surfaces and / or the removal of coating in the field of the optical industry, the Medical technology, the pharmaceutical industry, painting technology, microtechnology and / or precision engineering and others. Use according to the preceding claim Treatment of soft surfaces, to remove particulate, biotic and / or abiotic coatings and / or deposits and / or for removing paint layers. Use according to one of the two previous ones claims for the treatment of surfaces in the sub-micron range.