Combination nozzle for blasting a component

Abstract

The present invention relates to a combination nozzle (50) for blasting a component with a volumetric flow (VS) of dry-ice particles (A) and an additive, in particular a solvent (B), the combination nozzle (50) comprising a mixing nozzle (54), a volumetric-flow nozzle (55) and a dispensing unit (56). The volumetric-flow nozzle (55) and the dispensing unit (56) each open into an inner volume (54.3) of the mixing nozzle (54) and generate the volumetric flow (VS).

Description

[0001] COMBINED NOZZLE FOR RADIATION OF A COMPONENT

[0002] DESCRIPTION

[0003] Technical field

[0004] The present invention relates to a combination nozzle for irradiating a component.

[0005] State of the art

[0006] Machine components are frequently subjected to high mechanical and / or thermal stresses during their manufacture and operation. As a result of these stresses, the components can wear out, corrode, or develop cracks. Therefore, particularly in the field of turbomachinery, such as turbofan engines for aircraft, their components are subjected to non-destructive testing at prescribed intervals.

[0007] A common method for non-destructive testing is the so-called "penetrant testing." Here, the component is first cleaned to remove contaminants that may have accumulated during operation, particularly from lubricating oils and greases (so-called "surface cleaning"). A penetrant is then applied to the component's surface to make surface defects visible, such as cracks or cavities. The penetrant adheres to these defects, for example, due to capillary action, making them clearly visible during subsequent visual inspection. Before the visual inspection, the surface can be cleaned to remove excess penetrant; at any defects, the penetrant will ooze out ("bleed"), making the defects clearly visible.

[0008] To improve the detection rate, for example, after the initial visual inspection, a so-called "re-wiping" with a brush can be performed on areas that were conspicuous during the first visual inspection. A genuine defect will then bleed. In some cases, the penetrant test may also include a so-called "re-development," in which a developer is applied again after the re-wiping, e.g., a non-aqueous wet developer or a developer powder.

[0009] Description of the invention

[0010] The present invention is based on the technical problem of providing an advantageous device for irradiating a component.

[0011] This is achieved according to the invention with the combination nozzle according to claim 1. In this nozzle, an additive, e.g., a solvent, is added to a volumetric flow of dry ice particles. This can, for example, improve the abrasive cleaning effect, particularly on oily or greasy component surfaces. The combination nozzle allows process parameters, such as the pressure of the volumetric flow and the contact time on the component surface, to be controlled or adjusted, which can be advantageous, for example, with regard to reproducibility. The metering of the additive, especially the solvent, within the combination nozzle can also enable good process control and, for example, a robust design.

[0012] The combination nozzle can be particularly useful in the context of the penetrant test described above. For example, if the dry ice / solvent stream is used instead of a brush for "wiping" (see above), excessive removal of the previously applied penetrant—i.e., washing it out of defects, especially small cracks—can be prevented. The increased reproducibility and objectivity can also be advantageous for automation, allowing component testing with reduced intervention or even entirely without human intervention.

[0013] Preferred embodiments are found throughout the disclosure and particularly in the claims, although the description of features does not always differentiate between the various claim categories. For example, if a penetrant test with the combination nozzle is described, this is to be understood as a disclosure of a corresponding method and a corresponding use, and vice versa. Irradiation with the volume flow of dry ice particles, i.e., carbon dioxide (CO2) particles, can enable gentle surface cleaning without CO2 residues, since the CO2 particles sublimate within a short time after impacting the component surface, i.e., they change directly from a solid to a gaseous state. If, in comparison, sand or plastic were used as an abrasive medium, the surface could be damaged or contaminants could remain, e.g., in the form of sand or plastic dust.

[0014] With regard to penetrant testing, the inventors observed undesirable washout, particularly during the subsequent wiping process, when the penetrant is mechanically removed, for example, with a brush soaked in solvent. This manual process is also difficult to automate, and the process parameters (e.g., speed and solvent quantity) then depend heavily on the individual tester. Partial washout can be detrimental, at least with regard to comparability.

[0015] The additive added to the dry ice or CO2 flow in the combination nozzle is preferably a solvent. This solvent is particularly suitable for dissolving oils, especially for penetrant testing. Suitable solvents include, for example, alcohols such as ethanol, n-butanol, isopropanol, and / or methanol (improving the cleaning effect of the CO2 particles, which then remove the compounds dissolved by the solvent).

[0016] According to a preferred embodiment, the dispensing unit has an injection needle with a dispensing opening, which is arranged in the volumetric flow for dispensing the additive, in particular solvent, in a liquid state. The injection needle has, for example, an outer diameter of at most 5 mm, preferably at most 3 mm, in the region of the dispensing opening, with possible lower limits (independent of this) of at least 0.5 mm or 1 mm.

[0017] The injection needle's dispensing orifice is positioned within the flow stream in such a way that, for example, the liquid solvent is dispensed into it. This means that the flow of CO2 particles passing the dispensing orifice absorbs the escaping liquid and transports it to the component surface. The quantities dispensed, for example of the liquid solvent, into the flow stream can be in the microliter range.

[0018] In a preferred embodiment, the dispensing opening of the injection needle lies on a connecting line between the inlet and outlet openings of the mixing nozzle; it is thus arranged in the flow path. This connecting line, in particular the connecting straight line, passes through both the inlet and outlet openings of the mixing nozzle, preferably at their centers. Generally, the inlet and outlet openings of the mixing nozzle can preferably be approximately the same size.

[0019] In a preferred embodiment, the injection needle is arranged at an acute angle with respect to a downstream direction of the volume flow relative to the line connecting the inlet and outlet openings of the mixing nozzle. The term "downstream" here refers to the volume flow during the operating state of the combination nozzle. The downstream direction thus means the direction of the volume flow that flows from the inlet opening through the internal volume of the mixing nozzle and towards its outlet opening; i.e., the outlet opening is located further downstream than the inlet opening of the mixing nozzle.

[0020] According to a preferred embodiment, the combination nozzle further comprises an additional dispensing unit that also opens into the internal volume of the mixing nozzle. Thus, two dispensing units are provided, each capable of dispensing an additive into the volume flow.

[0021] In a preferred embodiment, the volumetric flow nozzle is configured in a further operating state to generate a volumetric flow from compressed air, wherein the further dispensing unit is configured in this further operating state to add a developer to the volumetric flow before it exits the outlet opening of the mixing nozzle. In a preferred embodiment, the further dispensing unit has a spray device that is arranged in the volumetric flow for dispensing the developer in a liquid or solid state. A spray device is understood here to be a nozzle that dispenses the solvent over a certain cross-section of the volumetric flow, preferably by spraying it into the volumetric flow.In simplified terms, the further output unit is therefore arranged at the volume flow in order to spray the liquid or solid developer into the volume flow; thereby, the volume flow of CO2 particles flowing past the spray device takes up the sprayed developer and transports it to the surface of building 1.

[0022] The invention also relates to a method for treating the surface of a component with a combination nozzle, in which the dry ice particles and the additive are dispensed as a combined jet from the combination nozzle onto the surface of the component. Overall, this reduces the number of tools or spray nozzles required, and several work steps can be adapted without tool changes or modifications, which is particularly advantageous with regard to automation.

[0023] The invention also relates to a method for testing a component using a penetrant test, in which i) a penetrant is applied to a surface of the component; and ii) the surface is optically detected; wherein the surface of the component is treated at least locally with the aforementioned method before and / or after step i). The treatment of the component surface according to the invention can take place before the application of the penetrant in step i) and / or after the first optical detection in step ii); before step i) this is referred to as "surface cleaning" and after step ii) as "intermediate cleaning" (as an alternative to "wiping"). During surface cleaning, any contamination resulting from the manufacture and / or operation of the component is removed from its surface.For this process, these contaminants are first (partially) dissolved by the solvent present in the flow and then removed from the component surface by a mechanical cleaning effect of the impacting CO2 particles. This surface cleaning serves as an initial cleaning step, i.e., the removal of contaminants present on the component surface, which can lead to better results with regard to the subsequent optical inspection of the surface.

[0024] The intermediate cleaning, on the other hand, takes place after the application of the penetrant and after the initial optical inspection of the component surface (i.e., after step ii) and is aimed at removing any excess penetrant from step i) from the surface without washing it out of small cracks or defects. This intermediate cleaning is preferably carried out locally in areas where penetrant was still detected in step ii).

[0025] Generally, penetrant testing is preferably performed using fluorescent penetrant testing (FPI), meaning a fluorescent penetrant is used. During optical detection, this can then be made visible, for example, by UV irradiation, which allows for good luminance contrasts. As a result, even relatively small defects where the penetrant has accumulated can be detected.

[0026] Generally, there is preferably at least one development step in which the penetrant is developed. During this process, the penetrant can, for example, become deeply embedded in a defect or create increased contrast with the surrounding surface area. In the case of a fluorescent penetrant, it can be irradiated with UV radiation before intermediate cleaning, allowing the identification of those areas on the surface where penetrant is still present. The subsequent intermediate cleaning then helps to differentiate between actual defects from which the penetrant is not removed by irradiation and residues that were not removed during the initial irradiation.According to a preferred embodiment, there is at least one further operating state in which iii) the surface is further developed after optical detection by irradiating the surface with a volume flow of compressed air and a developer.

[0027] Therefore, without any modifications to the combination nozzle, the compressed air volume flow and the penetrant can be dispensed with it in the continued operating state, allowing for (preferably local) re-engineering of specific component areas, e.g., particularly critical or difficult-to-detect areas. This enables further improved component testing and is also advantageous with regard to potential automation.

[0028] In a preferred embodiment iv) the surface is optically scanned again after re-development, i.e., a further optical inspection is carried out to assess the condition of the component.

[0029] As mentioned at the outset, the present subject matter focuses in particular on automation, which is why, in the preferred embodiment, the blasting process is robot-guided. For example, the combination nozzle from which the blasting media is dispensed can be guided along the surface by a robot arm. This allows, for example, combined with prior automated image acquisition and processing, the targeted approach to those areas that require further or intermediate cleaning to differentiate between defects and penetrant residues.

[0030] In a preferred embodiment, the tested or examined component is a component of a turbomachine; reference is also made to the remarks within the framework of the prior art assessment. In particular, components intended for installation in the gas channel, such as impeller blades and channel plates, etc., can be subjected to considerable stresses, which is why the reliable detection of defects is of particular importance. According to a preferred embodiment, the component is additively manufactured. This means that it can be built up layer by layer from a previously formless or shape-neutral material, for example, using a powder bed fusion process, based on a data model. Due to the layer-by-layer construction, the surface can be complex, which, conversely, can promote penetrant residues during penetrant testing or necessitate a particularly high level of test accuracy.Therefore, the advantages mentioned at the beginning and the associated objectification come into play to a beneficial effect.

[0031] The invention also relates to a use of the combination nozzle described above in the method described above.

[0032] Brief description of the drawings

[0033] The invention will now be explained in more detail using several exemplary embodiments, whereby the individual features within the scope of the dependent claims may also be essential to the invention in other combinations, and no distinction will be made in detail between the different claim categories.

[0034] In detail, it shows

[0035] Figure 1 shows a schematic representation of a turbofan engine, to illustrate an advantageous application environment;

[0036] Figure 2 shows a combination nozzle in an operating state;

[0037] Figure 3 shows a combination nozzle in another operating state;

[0038] Figure 4 shows the process of an intrusion test in a flowchart;

[0039] Figures 5a-c show selected steps in the penetrant testing procedure according to Figure 4 in detail. Preferred embodiment of the invention

[0040] Fig. 1 shows a turbomachine 1, specifically a turbofan engine, in axial section. The turbomachine 1 is functionally divided into compressor 1a, combustion chamber 1b, and turbine 1c. Both compressor 1a and turbine 1c are each constructed from several stages, each consisting of a guide vane and a subsequent rotor blade assembly. In compressor 1a, the intake air is compressed and then combusted with added kerosene in the downstream combustion chamber 1b. The component discussed below can be used in such a turbomachine 1; it could, for example, be a blade arranged in the compressor or hot gas channel (guide vane 5 or rotor blade 6), but it could also be a component installed elsewhere in the machine.

[0041] Fig. 2 shows a combination nozzle 50, which comprises a mixing nozzle 54, a volumetric flow nozzle 55, and a dispensing unit 56. The mixing nozzle 54 defines an internal volume 54.3 located between an inlet opening 54.1 and an outlet opening 54.2. The volumetric flow nozzle 55 opens through the inlet opening 54.1 into the internal volume 54.3 of the mixing nozzle 54 and is configured in an operating state ZI to generate a volumetric flow VS of dry ice particles A, which flows through the internal volume 54.3 of the mixing nozzle 54 in the downstream direction indicated by an arrow. The volumetric flow VS is generated in the volumetric flow nozzle 55 from liquid CO2 40 and compressed air C.

[0042] Via the dispensing unit 56, which also opens into the internal volume 54.3 of the mixing nozzle 54, a solvent B is added to the volume flow VS in the operating state ZI of the combination nozzle 50 before it exits the outlet opening 54.2. For this purpose, the dispensing unit 56 has an injection needle 56.1 with an outlet opening 56.2 arranged in the volume flow VS. After exiting the outlet opening 54.2, the volume flow VS encounters a surface 30.1 of a component 30 to be tested (see Fig. 5a-c). Fig. 3 shows a combination nozzle 50 in a further operating state Z2. For this, the combination nozzle also includes, compared to Fig. 2, a further dispensing unit 57, which is configured to dispense a developer D. As can be seen in Fig. 3, the volume flow nozzle in the further operating state Z2 generates a volume flow VS' which consists solely of compressed air C. In the configuration shown in Fig.In the embodiment shown in Figure 3, the further dispensing unit 57 is equipped with a spray device 57.1 and is arranged on the volume flow VS' in such a way that the developer D is mixed with the volume flow VS' before it exits the dispensing opening 54.2.

[0043] Figure 4 illustrates a penetrant test 10 in a schematic flow diagram. After an optional initial irradiation 11 of the surface 30.1 of the component 30 with the volume flow VS of dry ice particles A and the solvent B, a penetrant 31 is applied to its surface 30.1 12. The applied penetrant 31 is developed 13. Subsequently, the surface 30.1 is optically scanned for the first time 14, whereby any detected defects are then treated by intermediate cleaning 15 with the volume flow VS. The penetrant is then developed a second time 16 before the surface is optically scanned again 17. Steps 11 to 17 are referred to as the operating state ZI of the combination nozzle 50.

[0044] Subsequently, the surface 30.1 is re-developed by blasting the surface 30.1 with a volume flow VS' of compressed air C and a developer D 18 and optically inspected again 19. Steps 18 and 19 are thus referred to as the further operating state Z2 of the combination nozzle 50. As detailed in the introductory description, some of the steps are optional.

[0045] Fig. 5a illustrates the first irradiation 11 in detail. The volume flow VS, containing the CO2 particles A and the solvent B, in this example ethanol, encounters any contaminants 35 present on the surface 30.1 of the component 30 to be examined and dissolves them. Fig. 5b shows the component 30 after the application 12 of the penetrant 31. As can be seen, the penetrant 31 was drawn into the two defects 32.1, 32.2 due to the capillary forces described above. In a cleaning step (e.g., spraying with solvent), the penetrant can be removed from the surface, and then the first optical inspection 14 takes place.

[0046] A subsequent intermediate cleaning step 15 is illustrated in Fig. 5c. Here, the surface 30.1 is blasted with the volume flow rate VS, thereby removing any remaining traces of the penetrant 31, as exemplified to the left of the defect 32.1, from the component surface 30.1. Conversely, due to the selected particle size, the penetrant 31 located in the two defects 32.1, 32.2 is not washed out; thus, the defects 32.1, 32.2 can still be detected.

[0047] During irradiation 11 and intermediate cleaning 15 of operating state ZI and / or irradiation 17 of further operating state Z2, the combination nozzle 50, from which the volume flow VS, VS' is discharged, can be moved along the surface 30.1 guided by a robot arm 46. The volume flow VS, VS' is discharged from the combination nozzle 50 in each instance.

[0048] REFERENCE MARK LIST

[0049] Turbomachine 1

[0050] Compressor la

[0051] Combustion chamber lb

[0052] Turbine 1c

[0053] Guide vane 5

[0054] Running shovel 6

[0055] Penetration test 10

[0056] Irradiation (first, over a surface) 11

[0057] Application of the penetrant 12

[0058] First development of the penetrant 13

[0059] Optical surface detection (first) 14

[0060] Interim cleaning 15

[0061] Further development of the penetrant 16

[0062] Optical surface detection (second) 17

[0063] Irradiation (repeated, local) 18

[0064] Optical surface detection (third) 19

[0065] Component 30

[0066] Surface area to be examined 30.1

[0067] Penetrating agent 31

[0068] Defects 32.1, 32.2

[0069] Pollution 35 liquid CO2 40

[0070] Volume flow rate VS, VS'

[0071] Combination nozzle 50

[0072] Mixing nozzle 54

[0073] Inlet opening (of the mixing nozzle) 54.1

[0074] Outlet opening (of the mixing nozzle) 54.2

[0075] Internal volume (of the mixing nozzle) 54.3

[0076] Volume flow nozzle 55

[0077] Output unit 56, further output unit 57

[0078] Spray device (of the further dispensing unit) 57.1

[0079] Injection needle (of the further dispensing unit) 57.2

[0080] Dispensing opening (of the injection needle of the further dispensing unit) 57.3 Dry ice particles A

[0081] Solvent B

[0082] Compressed air C

[0083] Developer D

Claims

REQUIREMENTS 1. Combination nozzle (50) which is configured in at least one operating state (ZI) for irradiating a component with a volume flow (VS) of dry ice particles (A) and an additive, in particular solvent (B), comprising: a mixing nozzle (54) which defines an internal volume (54.3) located between an inlet opening (54.1) and an outlet opening (54.2); a volume flow nozzle (55) which opens through the inlet opening (54.1) into the internal volume (54.3) of the mixing nozzle (54) and is configured in the operating state (ZI) to generate the volume flow (VS) from the dry ice particles (A); and an output unit (56) which also opens into the internal volume (54.3) of the mixing nozzle (54) and is configured in the operating state (ZI) to add the additive to the volume flow (VS) before it exits the outlet opening (54.2) of the mixing nozzle (54).

2. Combination nozzle (50) according to claim 1, wherein the dispensing unit (56) has an injection needle (56.1) with a dispensing opening (56.2) which is arranged for dispensing the additive in a liquid state in the volume flow (VS).

3. Combination nozzle (50) according to claim 2, wherein the dispensing opening (56.2) of the injection needle (56.1) is located on a connecting line between the inlet opening (54.1) and the outlet opening (54.2) of the mixing nozzle (54).

4. Combination nozzle (50) according to claim 2 or 3, wherein the injection needle (56.1) is arranged at an acute angle with respect to a downstream direction of the volume flow (VS) relative to a / the connecting line between the inlet opening (54.1) of the mixing nozzle (54) and the outlet opening (54.2) of the mixing nozzle (54).

5. Combination nozzle (50) according to one of the preceding claims, further comprising a further dispensing unit (57) which also opens into the internal volume (54.3) of the mixing nozzle (54).

6. Combination nozzle (50) according to claim 5, in which the volume flow nozzle (55) is configured in a further operating state (Z2) to generate a volume flow (VS') from compressed air (C), wherein the further output unit (57) is configured in the further operating state (Z2) to add a developer (D) to the volume flow (VS') before it exits the outlet opening (54.2) of the mixing nozzle (54).

7. Combination nozzle (50) according to claim 6, wherein the further dispensing unit (57) has a spray device (57.1) which is arranged for dispensing the developer (D) in a liquid or solid state in the volume flow (VS').

8. Method for acting on a surface (30.1) of a component (30) with a combination nozzle (50) according to one of the preceding claims, in which, in the operating state (ZI), the dry ice particles (A) and the additive, in particular the solvent (B), are discharged as a common jet from the combination nozzle (50) onto the surface (30.1) of the component (39).

9. Method for testing a component (30) using an indentation test (10), wherein: i) an indenter (31) is applied to a surface (30.1) of the component (30) (12); and ii) the surface (30.1) is optically detected (17); wherein the surface (30.1) of the component (30) is at least locally acted upon before and / or after step i) using a method according to claim 11.

10. Method according to claim 9, wherein in a further operating state (Z2): iii) the surface (30.1) is further developed (17) after optical detection (17) by blasting the surface (30.1) with a volume flow (VS') of compressed air (C) and a developer (D) issued from the combination nozzle (50).

11. Method according to claim 10, wherein: iv) the surface (30.1) is optically detected again (18) after re-development (17).

12. Use of a combination nozzle (50) according to one of claims 1 to 7 for irradiating a component of a turbomachine, in particular in a method according to one of claims 8 to 11.

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