Cleaning laser assembly and method for removing an asbestos-containing material cover layer from metallic surfaces

Abstract

The invention relates to a cleaning laser assembly (1) and a method for removing an asbestos-containing material (2) cover layer (3) from metallic surfaces (4).

Description

[0001] Cleaning laser arrangement and method for removing a covering layer containing asbestos materials from metallic surfaces

[0002] The invention relates to a cleaning laser arrangement for removing a covering layer containing asbestos materials from metallic surfaces during a cleaning process.

[0003] Furthermore, the invention relates to a method for removing a covering layer containing asbestos-containing materials from metallic surfaces during a cleaning process, wherein during the cleaning process an asbestos fibre concentration at the workplace in the shift average value is below an asbestos fibre acceptance concentration of 10,000 asbestos fibres / m 3 , abbreviated F / m 3 , lies.

[0004] Asbestos is classified as a carcinogenic hazardous substance according to Annex VI of Regulation (EC) No. 1272 / 2008 and the German Hazardous Substances Ordinance (GefStoffV) (Category 1A) and is subject to a general ban on its use. The only exceptions are demolition, renovation, and maintenance work in accordance with Annex II No. 1 of the GefStoffV.

[0005] The following silicates with a fibrous structure are referred to as asbestos: actinolite, amosite, antophyllite, chrysotile, crocidolite, and tremolite. Asbestos-containing materials are mixtures and products containing asbestos in which the performance of an activity may lead to the formation or release of fibrous dust.

[0006] The protective measures required according to Annex I No. 2.4 of the Ordinance on Hazardous Substances and the organizational requirements for permitted activities involving asbestos or asbestos-containing materials are summarized and specified in the Technical Rules for Hazardous Substances TRGS 519 "Asbestos - Demolition, Renovation or Maintenance Work" in the version dated 31 March 2022. Reference will always be made to this version below when referring to TRGS 519. The protection of employees generally also ensures the protection of third parties and the environment.

[0007] When working with asbestos, a high level of exposure to asbestos fibers is generally assumed (worst case), so that, as a rule, all requirements of Annex I No. 2.4 of the Hazardous Substances Ordinance must be implemented. This applies in particular to:

[0008] - Existence of certain qualifications / expertise according to TRGS 519

[0009] - the regular implementation of occupational health checks

[0010] - compliance with employment restrictions

[0011] - special construction site facilities such as locks for personnel and materials

[0012] - technical ventilation measures, negative pressure maintenance

[0013] - wearing personal protective equipment

[0014] For activities involving asbestos that result in low exposure, the Hazardous Substances Ordinance (GefStoffV) permits deviations from these requirements in Annex I No. 2.1. In conjunction with the risk concept for carcinogenic substances in TRGS 910, activities with low exposure or low risk exist if it has been demonstrated that the asbestos fiber concentration at the workplace, as a shift average, is below the asbestos fiber acceptance concentration of 10,000 asbestos fibers / m 3 lies .

[0015] "Low-emission processes" according to TRGS 519 No. 2.9 are those activities with low exposure that have been tested and recognized by the authorities or by the statutory accident insurance institutions. A low-emission process is based on a standardized work procedure for which it has been demonstrated that the concentration of asbestos is safely below the acceptable level.

[0016] If the limit values ​​for other hazardous substances, e.g. mineral dust, quartz-containing dust, emissions from tar-derived materials, which may also be released as a result of the process, are not complied with, appropriate protective measures must be specified in the process description.

[0017] For the statutory accident insurance institutions, the testing and recognition of low-emission procedures according to TRGS 519 is carried out by the "Construction" department of the German statutory accident insurance (DGUV) under the leadership of the DGUV working group "Low-emission procedures according to TRGS 519 for activities involving asbestos-containing materials".

[0018] The object of the invention is therefore to provide both a cleaning laser arrangement and a method for removing a covering layer containing asbestos-containing materials from metallic surfaces, wherein the cleaning laser arrangement is suitable for carrying out the method in particular as a low-emission method according to TRGS 519.This object is achieved in a cleaning laser arrangement of the type mentioned at the outset in that the cleaning laser arrangement has a cleaning laser having laser optics emitting laser light and a suction device having a suction opening, wherein during the cleaning process the covering layer of the metallic surface can be removed by the laser light emitted by the laser optics, so that the asbestos-containing material can be at least partially released, wherein the suction opening is arranged adjacent to the cleaning laser, so that the removed covering layer can be sucked into the suction device via the suction opening together with the released asbestos-containing material. Ablable covering layer here means that the laser light emitted by the laser optics evaporates and / or burns and / or blasts off the covering layer of the metallic surface.Advantageously, the cleaning laser system provides a highly efficient process for removing a covering layer containing asbestos-containing materials from metallic surfaces during a cleaning operation, releasing minimal asbestos fiber concentrations. This ensures that the activities in the work area are only exposed to minimal asbestos exposure. The cleaning laser system even conveniently enables a low-emission process in accordance with TRGS 519.

[0019] Preferably, the extraction system should also have a TRGS 519 asbestos approval.

[0020] Low exposure activities are low-risk activities as defined by TRGS 910, where the asbestos acceptance concentration is 10,000 asbestos fibres / m 3is not reached (for the determination of the asbestos fibre concentration see number 4.3 paragraph 1, TRGS 519 in the version of 31 March 2022). If such activities are carried out inside buildings, it must be demonstrated after completion of all work that an asbestos fibre concentration of 500 F / m 3 and an upper Poisson value of 1000 F / m 3 in the room air is exceeded (measurement according to VDI 3492).

[0021] The term "low-emission processes" includes those activities according to 2.8 of TRGS 519 that have been tested and recognized by the authorities or by the statutory accident insurance institutions. The basis for the corresponding testing is the assessment criteria established by the Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA). The processes recognized by the statutory accident insurance institutions are published in BGI 664 with current additions (see www.dguv.de) (for the determination of the asbestos fiber concentration within the framework of the process testing, see TRGS 519, number 4.3 paragraph 2).

[0022] In a cleaning laser arrangement that is advantageous in this regard, the cleaning laser is designed as an Nd:YAG solid-state laser.

[0023] According to an additional advantageous embodiment of the cleaning laser arrangement, the power density of the cleaning laser has individual pulse powers in the range of several hundred kilowatts. The individual pulse powers are expediently greater than 200 kW, preferably greater than 500 kW, and more preferably greater than 1,000 kW. The high power densities make ablation economically viable.

[0024] According to a further advantageous development of the cleaning laser arrangement, the suction device has a collection device for the extracted asbestos-containing material. The collection device, which is designed, for example, like a vacuum cleaner bag, allows the asbestos fibers released and extracted by the laser ablation to be separately collected. Laser ablation, also called laser vaporization, is the removal of a covering layer from a surface by bombarding it with pulsed laser light, also called laser radiation. The high-power laser light used in this process leads to rapid heating and the formation of a plasma on the surface.

[0025] In this regard, the collection device of the extraction system is replaceable. Furthermore, the collection device is preferably lockable before replacement, ensuring that no asbestos fibers are released during replacement. This replaceable collection device allows for easy continuation of work without significant loss of time and proper disposal of the asbestos fibers.

[0026] The extraction system also includes a filter device, which is preferably designed as a HEPA filter. The filter device can clean the extracted air, along with the removed covering layer and the released asbestos fibers. HEPA filters (High Efficiency Particulate Air Filters) are particulate filters capable of filtering out over 99.9 percent of all dust particles larger than 0.1–0.3 micrometers (cm), such as viruses, respirable dust, mite eggs and excretions, pollen, smoke particles, asbestos, bacteria, various toxic dusts, and aerosols.

[0027] Preferably, the filter device also includes a filter shaker. The filter shaker makes it possible to clean the filter device of asbestos fibers that have accumulated on it and to collect the asbestos fibers, for example, in the collection device. The filter shaker is expediently designed as a manually operated, mechanically operated filter shaker.

[0028] The cleaning laser arrangement advantageously has an extraction device with a suction power of greater than 3 kW, preferably greater than 5 kW, and more preferably greater than 7 kW. Suction powers of this magnitude ensure reliable extraction of the asbestos fibers during the cleaning process. The extraction device is preferably designed as a vacuum extraction system. The negative pressure prevailing in the extraction device during the vacuum ensures that the asbestos fibers, once extracted, remain in the collection device of the extraction device.

[0029] According to an additional advantageous embodiment of the cleaning laser arrangement, the cleaning laser arrangement has a housing, wherein the housing is designed such that the cleaning laser remains free of asbestos during the cleaning process. In this regard, the housing is designed as a casing. Furthermore, it is possible to form the housing from a tubular film having a defined thickness, expediently from a 100 μm thick LDPE tubular film. Other tubular films with thicknesses, for example in the range from 50 μm to 250 μm are also conceivable. Due to the housing, the cleaning laser is preferably not exposed to asbestos, so that it can still be used for other applications outside the asbestos sector.

[0030] Furthermore, the cleaning laser arrangement has a control device with a control function, which is expediently configured to automatically adapt the extraction flow of the extraction device to the parameters of the cleaning laser. Adapting the extraction device is advantageous because, for example, a higher energy density and a shorter pulse length may release more asbestos fibers. In particular, a higher power density and / or shorter pulse length can lead to stronger extraction. The control device thus automatically and optimally adjusts the extraction flow of the extraction device.

[0031] The control device is advantageously configured to trigger a follow-up run of the extraction system after the cleaning process has been completed. This ensures that after the cleaning process has stopped, the extraction system continues to extract the work area for a certain period of time, thereby also extracting any asbestos fibers that may have been released but not extracted.

[0032] According to an advantageous embodiment of the cleaning laser assembly, the cleaning assembly has a holding device on which the cleaning laser can be arranged such that it always has the same distance from the metallic surface having the cover layer. With a constant distance to the metallic surface, it is sufficient to parameterize the cleaning laser before the cleaning process. Furthermore, it is easier to control the feed of the cleaning assembly during the cleaning process. Furthermore, the workload for the operator is also reduced. The holding device is expediently designed as an industrial robot.

[0033] Furthermore, the problem is solved by a method of the type mentioned above in that the top layer is removed using a cleaning laser arrangement comprising a cleaning laser with a laser optic that emits laser light and an extraction device with an extraction opening. The level of asbestos fiber exposure is to be determined by workplace measurements in accordance with TRGS 402 in conjunction with DIN EN 689. This is described by the measurement result of the average asbestos fiber concentration (shift average) based on an 8-hour work shift.Removing the top layer using a cleaning laser system provides a highly efficient method for removing a top layer containing asbestos-containing materials from metallic surfaces during a single cleaning process, releasing minimal concentrations of asbestos fibers, so that workers in the work area are exposed to only minimal asbestos exposure. A particularly advantageous method in this regard is a low-emission process according to TRGS 519.

[0034] According to an additional advantageous embodiment of the method, during the cleaning process, the removed covering layer, together with the released asbestos-containing material, is sucked into the extraction device through a suction opening. This ensures that only a low concentration of asbestos fibers is released.

[0035] According to a further advantageous method, the cleaning laser is designed as an Nd:YAG solid laser and emits non-visible infrared laser light, also referred to as laser radiation. The infrared laser light is preferably emitted at a wavelength of 1,064 nm. Surprisingly, it has been found that an Nd:YAG solid laser with an emitted wavelength of 1,064 nm delivers optimal removal results for the covering material containing asbestos. In an additional preferred development of the method, the power density of the cleaning laser arrangement has individual pulse powers in the range between 200 kW and 2,000 kW and the pulse lengths are in the range from 50 ns to 200 ns. The combination of power density and pulse length in the aforementioned ranges results in significant heating of the surface during the pulse.The power density is preferably a few hundred kilowatts, in particular between 200 kW and 500 kW. Since heat conduction into the volume of the covering layer is comparatively slow, the quickly introduced heat cannot usually dissipate. Thus, the surface of the covering layer containing the asbestos material is heated to such an extent that it enters a plasma state. This plasma can become so dense that it absorbs a large part of the laser light, thus protecting the underlying surface from further heating. The cleaning laser arrangement ensures optimal ablation of the covering layer.

[0036] According to a further advantageous method, the suction device comprises a filter device, wherein the filter device further comprises a filter shaker suitable for cleaning the filter device. This ensures that the suctioned-off, removed covering layer can always be optimally filtered together with the asbestos-containing materials, and that the filter device does not become clogged with asbestos fibers, for example.

[0037] According to an additional preferred embodiment of the method, the cleaning laser arrangement has a control device with a control functionality that is configured to automatically adapt an extraction flow of the extraction device to a parameterization of the cleaning laser. Adapting the extraction device is advantageous because, for example, with a higher energy density and a shorter pulse length, more asbestos fibers may be released by the laser ablation during the cleaning process. In particular, a higher power density and / or shorter pulse length can lead to stronger extraction. The control device thus automatically adapts the extraction flow of the extraction device to optimally suit the laser ablation.

[0038] The control device is advantageously configured to trigger a follow-up run of the extraction system after the cleaning process has ended. This ensures that after the cleaning process has stopped, the extraction system continues to extract the work area for a certain period of time, thereby also removing any asbestos fibers that may have been released and not extracted. The follow-up run lasts between 30 seconds and 10 minutes.

[0039] Furthermore, according to an additional embodiment of the preferred method, the cleaning laser arrangement has a control device with a control functionality, wherein the control device is configured to activate the suction device when the cleaning laser is switched on. This ensures that the suction device is switched on during a cleaning process with the cleaning laser, thus always vacuuming away the removed covering layer together with the asbestos-containing material.

[0040] The invention is explained in more detail below using the attached drawing, which shows

[0041] Figure 1 shows a schematic representation of an embodiment of a preferred cleaning arrangement. Fig. 1 shows a schematic representation of an exemplary embodiment of a cleaning arrangement 1 for removing a covering layer 3 containing asbestos-containing materials 2 from metallic surfaces 4 during a cleaning process.

[0042] The following silicates with fibrous structure, actinolite, amosite, antophyllite, chrysotile, crocidolite and tremolite are referred to as asbestos.

[0043] Asbestos-containing materials 2 are mixtures and products containing asbestos where the performance of an activity may lead to the formation or release of fibrous dust.

[0044] The cleaning laser arrangement 1 has a cleaning laser 5, which has a laser optics 7 emitting a laser light 6, and a suction device 9 having a suction opening 8. The suction opening 8 is arranged adjacent to the cleaning laser 5, so that the cover layer 3 removed during the cleaning process by the laser light 6 emitted by the laser optics 7 is sucked together with the at least partially released asbestos-containing material 2 via the suction opening 8 into the suction device 9.

[0045] In this method, the cover layer 3 is removed from the metallic surface 4 by bombardment with pulsed laser light 6, forming a plasma. The cleaning laser 5 is expediently designed as an Nd:YAG solid-state laser 10. The Nd:YAG solid-state laser 10 emits non-visible infrared radiation with a wavelength of 1,064 nm. Other cleaning lasers 5 with shorter emission wavelengths are also conceivable in principle, but these are generally less effective in removing the cover layer 3 containing asbestos-containing material 2.

[0046] To remove the cover layer 3 at economically viable removal rates, high power densities with single-pulse powers in the range of several hundred kilowatts are required. The cleaning laser 5 used in the embodiment shown is a CLIO OO laser cleaning system from Clean Lasersysteme GmbH with the OSH80 laser optics. The nominal power of the CLIO OO laser cleaning system is 1,000 W; the single-pulse power density of the cleaning laser 5 used in the embodiment is several hundred kilowatts.

[0047] In an unrealized embodiment, a handheld OSH80 or Eff iScan optics and quick-change fiber were used. The single-pulse power densities used were greater than 200 kW, and in particular greater than 500 kW.

[0048] The pulse lengths are typically in the range of 50 ns to 200 ns. In the embodiment, a pulse length in the order of magnitude of 100 ns was chosen so that a significant heating of the surface 4 can take place during the pulse. Since heat conduction into the volume of the covering layer 4 is comparatively slow, the rapidly introduced heat cannot usually be dissipated, so that the covering layer 3 heats up to such an extent that it enters the plasma state. This plasma can become so dense that it absorbs a large part of the laser light 6, thus protecting the underlying surface from further heating.

[0049] The extraction device 9 is preferably designed as a vacuum extraction system. In this embodiment, the extraction device 9 used is a DG50EXP asbestos extraction system with asbestos approval according to TRGS519 from Delf in Industrial Vacuums, which has a suction power of 5 kW.

[0050] In other realized embodiments a suction power of 3 kW or 7 kW was used.

[0051] Furthermore, the suction device 9 has a collecting device 11 for the extracted asbestos-containing material 2. The collecting device 11 of the suction device 9 is preferably replaceable. Furthermore, the collecting device is designed such that it can be closed dust-tight during replacement, thus preventing the escape of asbestos-containing material 2.

[0052] Furthermore, the suction device 9 has a filter device 12, wherein the filter device 12 is expediently designed as a HEPA filter 13 of filter class H14. Additionally arranged on the filter device 12 is a filter shaker 14, which mechanically cleans the filter device 12 through manual operation.

[0053] In the embodiment shown, the cleaning laser arrangement 1 has an optional housing 15. The housing 15 is designed such that the cleaning laser 5 does not come into contact with the asbestos-containing material 2 during the cleaning process, i.e. remains asbestos-free. The housing 15 can optionally be designed, for example, as a housing 16, as shown in the embodiment, or as a tubular film. When using a tubular film, an LDPE tubular film with a thickness in the range of 50 / zm to 200 / zm, particularly preferably 100 / zm, of sufficient length is preferably used. In this embodiment, the cleaning laser arrangement 1 additionally has a control device 17 having a control functionality.The control device 17 is configured, among other things, to automatically adapt the suction flow of the suction device 9 to the parameterization of the cleaning laser 5 and / or to trigger a run-on of the suction device 9 after the cleaning process has ended and / or to switch on the suction device 9 when the cleaning laser 5 is switched on. If the cleaning laser arrangement does not have a control device 17, the suction device 9 should always be set to the maximum suction power.

[0054] Furthermore, the cleaning arrangement 1 has a holding device 18 on which the cleaning laser 5 can be arranged. The holding device 18, expediently a mobile frame or, as shown in the embodiment, an industrial robot 19 having several robot arms 23 arranged so as to be movable relative to one another, ensures that the laser optics 6 of the cleaning laser 5 always has the same distance 20 from the metallic surface 4 having the cover layer 3. In addition, the holding device 18 ensures a definite feed 22 of the cleaning laser 5. This significantly improves the quality of the laser cleaning compared to a hand-held cleaning laser 5.

[0055] The method for removing a covering layer 3 containing asbestos-containing materials 2 from metallic surfaces 4 during a cleaning process, wherein during the cleaning process an asbestos fiber concentration at the workplace in the shift average value is below an asbestos fiber acceptance concentration of 10,000 F / m 3 is characterized by the removal of the cover layer 3 by means of a cleaning laser arrangement 5, which has a cleaning laser 5 with a laser optics 7 emitting laser light 6 and a suction device 9 with a suction opening 8. The suction device 9 is suitable for sucking the cover layer 3 evaporated during the cleaning process together with the released asbestos-containing material 2 through a suction opening 8 into the suction device 9. The process is expediently a low-emission process according to TRGS 519.

[0056] Low exposure activities are low-risk activities within the meaning of TRGS 910, where the asbestos fibre acceptance concentration is 10,000 asbestos fibres / m 3 - abbreviated F / m 3 - is exceeded (for the determination of the asbestos fibre concentration see number 4.3 paragraph 1 of TRGS 519). If such activities are carried out inside buildings, it must be demonstrated after completion of all work that a fibre concentration of 500 F / m 3 and an upper Poisson ratio of 1000 F / m 3 in the room air is exceeded (measurement according to VDI 3492).

[0057] The term "low-emission processes" includes those activities according to number 2.8 of TGRS 519 that have been tested and recognized by the authorities or by the statutory accident insurance institutions. The basis for the corresponding testing is the assessment criteria established by the Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA). The processes recognized by the statutory accident insurance institutions are published in BGI 664 with current additions (see www.dguv.de) (for the determination of the asbestos fiber concentration within the framework of the process test, see number 4.3 paragraph 2, TRGS 519).

[0058] The cleaning laser arrangement 1 preferably has a cleaning laser 5 which is designed as an Nd:YAG solid-state laser 10 and emits non-visible infrared radiation, wherein the infrared laser light 6, which is also referred to as infrared radiation, is expediently emitted with a wavelength of 1,064 nm.

[0059] The power density of the cleaning laser arrangement 1 particularly has single pulse powers in the range between 200 kW and 2,000 kW, and the pulse lengths are in the range from 50 ns to 200 ns. A power density of a few hundred kilowatts, in particular from 200 kW to 500 kW, with a pulse length in the range from 80 ns to 150 ns, is particularly advantageous.

[0060] The suction device 9 has a filter device 12, wherein the filter device 12 further comprises a filter shaker 14 suitable for cleaning the filter device 12. Cleaning of the filter device 12 can be carried out manually as needed or controlled by the control device. Such cleaning can be triggered, for example, when the pressure loss occurring through the filter device 12, which can be detected in particular via a pressure difference measurement, rises above a threshold value.

[0061] Finally, the cleaning laser arrangement 1 has a control device 17 having a control functionality, which is configured to automatically adapt an extraction flow of the extraction device 9 to a parameterization of the cleaning laser 5 and / or to trigger a follow-up of the extraction device 9 after completion of the cleaning process, wherein the follow-up expediently runs between 30 s and 10 min and / or to switch on the extraction device 9 when the cleaning laser 5 is switched on.

Claims

Claims 1. Cleaning laser arrangement (1) for removing a covering layer (3) containing asbestos-containing materials (2) from metallic surfaces (4) during a cleaning process, characterized in that the cleaning laser arrangement (1) has a cleaning laser (5) having a laser optics (7) emitting a laser light (6) and a suction device (9) having a suction opening (8), wherein during the cleaning process the laser light emitted by the laser optics (7) emitted laser light (6) the cover layer (3) of the metallic surface (4) can be removed, so that the asbestos-containing material (2) can be at least partially released, wherein the suction opening (8) is arranged adjacent to the cleaning laser (5) so that the removed cover layer (3) together with the released asbestos-containing material (2) can be sucked into the suction device (9) via the suction opening (8).

2. Cleaning laser arrangement (1) according to claim 1, characterized in that the cleaning laser (5) is designed as an Nd:YAG solid-state laser (10).

3. Cleaning laser arrangement (1) according to claim 1 or 2, characterized in that the power density of the cleaning laser (5) has single pulse powers greater than 200 kW, preferably greater than 500 kW, more preferably greater than 1,000 kW.

4. Cleaning laser arrangement (1) according to one of the preceding claims, characterized in that the suction device (9) has a collecting device (11) for the suctioned-off, asbestos-containing material (2).

5. Cleaning laser arrangement (1) according to claim 4, characterized in that the collecting device (11) of the suction device (9) is replaceable.

6. Cleaning laser arrangement (1) according to one of the preceding claims, characterized in that the suction device (9) has a filter device (12), wherein the filter device (12) is expediently designed as a HEPA filter (13).

7. Cleaning laser device (1) according to claim 6, characterized in that the filter device (12) has a filter shaker (14), which is expediently designed as a manual, mechanically operated filter shaker (14).

8. Cleaning laser arrangement (1) according to one of the preceding claims, characterized in that the suction device (9) is designed as a vacuum suction device.

9. Cleaning laser arrangement (1) according to one of the preceding claims, characterized in that the suction device (9) has a suction power of greater than 3 kW, preferably greater than 5 kW, more preferably greater than 7 kW.

10. Cleaning laser arrangement (1) according to one of the preceding claims, characterized in that the cleaning laser arrangement (1) has a housing (15), wherein the housing (15) is designed such that the Cleaning laser (5) remains asbestos-free during the cleaning process.

11. Cleaning laser arrangement (1) according to claim 10, characterized in that the housing (15) is designed as a casing (16) or as a tubular film.

12. Cleaning laser arrangement (1) according to one of the preceding claims, characterized in that the cleaning laser arrangement (1) has a control device (17) having a control functionality, which is expediently configured to automatically adapt a suction flow of the suction device (9) to a parameterization of the cleaning laser (5).

13. Cleaning laser arrangement (1) according to claim 12, characterized in that the control device (17) is configured to trigger a follow-up of the suction device (9) after completion of the cleaning process.

14. Cleaning laser arrangement (1) according to one of the preceding claims, characterized in that the cleaning laser arrangement (1) has a holding device (18) on which the cleaning laser (5) can be arranged, so that it always has the same distance (20) from the cover layer (3) having a metallic surface (4).

15. Method for removing a covering layer (3) containing asbestos-containing materials (2) from metallic surfaces (4) during a cleaning operation, wherein during the cleaning operation an asbestos fibre concentration at the workplace (21) in the shift average is below an asbestos fibre acceptance concentration of 10,000 F / m 3characterized in that the removal of the cover layer (3) by means of a Cleaning laser arrangement (1) which has a cleaning laser (5) having a laser optics (7) emitting a laser light (6) and a suction device (9) having a suction opening (8).

16. Process according to claim 15, characterized in that the process is a low-emission process according to TRGS 519 in the version of 31 March 2022.

17. Method according to claim 15 or 16, characterized in that during the cleaning process the removed covering layer (3) together with the released asbestos-containing material (2) is sucked into the suction device (9) via a suction opening (8).

18. Method according to one of claims 15 to 17, characterized in that the cleaning laser (5) is designed as an Nd:YAG solid-state laser (10) and emits a non-visible infrared laser light (6).

19. Method according to claim 18, characterized in that the infrared laser light (6) is emitted with a wavelength of 1064 nm.

20. Method according to one of claims 15 to 19, characterized in that the power density of the cleaning laser arrangement (1) has single pulse powers in the range between 200 kW and 2000 kW and the pulse lengths are in the range from 50 ns to 200 ns.

21. Method according to one of claims 15 to 20, characterized in that the suction device (9) has a filter device (12), wherein the filter device (12) further comprises a filter shaker (14) which is suitable for cleaning the filter device (12).

22. Method according to one of claims 15 to 21, characterized in that the cleaning laser arrangement (1) has a control device (17) having a control functionality, which is configured to automatically adapt a suction flow of the suction device (9) to a parameterization of the cleaning laser (5).

23. Method according to one of claims 15 to 22, characterized in that the cleaning laser arrangement (1) has a control device (17) having a control functionality, wherein the control device (17) is configured to trigger a follow-up of the suction device (9) after completion of the cleaning process.

24. Method according to claim 23, characterized in that the follow-up runs between 30 s and 10 min.

25. Method according to one of claims 15 to 24, characterized in that the cleaning laser arrangement (1) has a control device (17) having a control functionality, wherein the control device (17) is configured to switch on the suction device (9) when the cleaning laser (5) is switched on.

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