PARTICLE COLLECTING DEVICE HAVING A CLEANING UNIT, AND CLEANING METHOD FOR A PARTICLE COLLECTING DEVICE

Abstract

A particle collecting device for collecting particles from surfaces for a particle analysis within the context of testing the technical cleanliness of test bodies, in particular work pieces and machines, with a cleaning unit.

Claims

1. A particle collecting device (1) for collecting particles from surfaces for a particle analysis when testing the technical cleanliness of test objects in a suction mode of the particle collecting device (1), the particle collecting device (1) comprising: a suction line (12) configured for aspirating a particle/air mixture from a surface to be tested; and a particle collection unit (120) configured to filter out aspirated particles of the particle/air mixture before it reaches a vacuum source (8), wherein the particle collecting device (1) comprises a cleaning unit (101) configured in such a manner that the particle collecting device (1) can be rinsed in a rinsing mode of the particle collecting device (1) by aspirating a cleaning liquid, in order to flush out particles accumulated during suction mode.

2. The particle collecting device according to claim 1, wherein the particle collecting device (1) comprises a second particle collection unit (121) for collecting the particles, the first particle collection unit (120) being a filter holder (25) or a centrifugal separator (11), and the second particle collection unit (121) being a filter holder (25), and the filter holder (25) being configured to hold an exchangeable analysis filter.

3. The particle collecting device according to claim 2, wherein the suction line (12) for aspirating the particle/air mixture from the surface to be tested is connected to the centrifugal separator (11) in such a manner that the aspirated particle/air mixture rotates in the centrifugal separator (11) and the particles can be flung against a wall and thus be separated in suction mode, the centrifugal separator (11) comprising a seat (100) for attaching a collecting vessel (17) for collecting the separated particles in a detachable manner, and wherein the centrifugal separator (11) comprises an immersion tube (22) to which a vacuum supply line (9) is connected in such a manner that the air suctioned out of the centrifugal separator (11) and flowing through the vacuum supply line (9) in suction mode flows through the analysis filter, which is disposed in the filter holder (25) and serves to retain the particles on a particle collecting surface of the analysis filter, before reaching the vacuum source (8).

4. The particle collecting device according to claim 3, wherein the suction line (12) is connected to the centrifugal separator (11) in a detachable manner, and the vacuum supply line (9) is connected to the filter holder (25) in a detachable manner, the suction line (12) being configured in such a manner that it can be replaced with the vacuum supply line (9) in order to implement the rinsing mode while the centrifugal separator (11) is bypassed in a fluid-conducting manner.

5. The particle collecting device according to claim 1, wherein the cleaning unit (101) comprises a liquid storage unit (102) configured to provide a cleaning liquid which is detachable or a separate component from the particle collecting device (1), and/or the liquid storage unit (102) has a storage capacity of 5 l.

6. The particle collecting device according to claim 5, wherein the liquid storage unit (102) is in operative connection with the suction line (12) in such a manner that the cleaning liquid can be aspirated by means of the suction line (12) in rinsing mode.

7. The particle collecting device according to claim 3, wherein the cleaning unit (101) comprises an adapter unit (103) configured for being connected to the centrifugal separator (11) in a detachable manner via the seat (100) for exchanging the collecting vessel (17) attached to the centrifugal separator (11) in a detachable manner.

8. The particle collecting device according to claim 7, wherein the adapter unit (103) comprises a connecting hose (105) having a switchable valve (104), the valve (104) being switchable between a fluid-conducting state and a fluid-blocking state.

9. The particle collecting device according to claim 8, wherein the connecting hose (105) forms a fluid-conducting channel section (122) between the centrifugal separator (11) and the vacuum source (8) when the valve (104) is in the fluid-conducting state, the valve (104) being switched to the fluid-blocking state in rinsing mode.

10. The particle collecting device according to claim 1, wherein the cleaning unit (101) comprises a membrane suction end portion (106) configured to be connected to the suction line (12) in a suction-air-conducting manner when in a connected state, a suction opening (62) formed by the suction line (12) and serving to aspirate the particle/air mixture being covered by an air-permeable membrane (123) in the connected state for aspirating a pure air mixture, which contains no particles.

11. The particle collecting device according to claim 10, wherein the particle collecting device (1) comprises a dry mode in addition to the rinsing mode, the membrane suction end portion (106) being connected to the suction line (12) in a suction-air-conducting manner in dry mode, and the membrane suction end portion (106) being bypassed in a suction-air-conducting manner and/or not being connected in a suction-air-conducting manner for aspirating the cleaning liquid in rinsing mode.

12. The particle collecting device according to claim 1, wherein the particle collecting device (1) comprises control means (107) configured to the effect that: in rinsing mode, the valve (104) is switched to the fluid-blocking state and the cleaning liquid can be aspirated from the liquid storage unit (102) through the suction line (12) for rinsing the particle collecting device (1); and in dry mode, the valve (104) is switched to the fluid-conducting state and the suction line (12) can aspirate air through the membrane suction end portion (106).

13. A cleaning method for cleaning a particle collecting device (1) for collecting particles from surfaces for a particle analysis when testing the technical cleanliness of test objects, in particular work pieces, machines and/or printed circuit boards, the cleaning method comprising the following steps: bringing a cleaning unit (101) into operative contact with the particle collecting device (1); rinsing a suction line (12) and a particle collection unit (120) with the cleaning liquid in a rinsing mode.

14. The cleaning method according to claim 13, further comprising rinsing a centrifugal separator (11) and/or a filter holder (25) with the cleaning liquid in order to flush out accumulated particles.

15. The cleaning method according to claim 13, further comprising the following steps: removing an analysis filter from the filter holder (25); bringing the suction line (12) into operative contact with a liquid storage unit (102) containing the cleaning liquid; bringing an adapter unit (103) into operative contact with the centrifugal separator (11) by means of a seat (100) of the centrifugal separator (11); connecting a free end of a connecting hose (105) to the vacuum source (8) in a fluid-conducting manner, the other end of the connecting hose (105) ending in the adapter unit (103); switching a valve (104) disposed in the connecting hose (105) to a fluid-blocking state; activating a rinsing mode of the particle collecting device (1) for aspirating the cleaning liquid using the suction line (12); deactivating the rinsing mode; connecting a membrane suction end portion (106) to the suction line (12); switching the valve (104) to the fluid-conducting state; activating the dry mode for suctioning fluid residue out of the particle collecting device (1) and for discharging liquid backed up in the centrifugal separator (11) via the connecting hose (105); deactivating the dry mode.

16. The particle collecting device according to claim 1, wherein the test objects comprise work pieces, machines and/or printed circuit boards.

17. The particle collecting device according to claim 1, wherein the cleaning unit (101) is configured in such a manner that the suction line (12) and the particle collection unit (120) can be rinsed in the rinsing mode.

18. The particle collecting device according to claim 3, wherein the seat (100) comprises a threaded connection (52).

19. The particle collecting device according to claim 12, wherein, in the rinsing mode, the cleaning liquid can be aspirated through the suction line (12) for rinsing the modules transporting the particle/air mixture.

20. The particle collecting device according to claim 19, wherein the modules for transporting the particle/air mixture comprise the suction line (12), the centrifugal separator (11), the immersion tube (22), the vacuum supply line (9) and/or the filter holder (25).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Other advantages, features and details of the invention are apparent from the following description of preferred exemplary embodiments and from the drawings.

[0036] FIG. 1a, FIG. 1b: are schematic illustrations of a preferred embodiment of the particle collecting device according to the invention, which comprises a cleaning unit for rinsing particle residue from the particle collecting device; and

[0037] FIG. 2a, FIG. 2b: are additional schematic illustrations of the particle collecting device from FIGS. 1a/b, cleaning now being carried out using only the suction line and the filter holder.

DETAILED DESCRIPTION

[0038] In the Figures, identical elements and elements having the same function are labeled with the same reference signs.

[0039] FIG. 1a shows a schematic illustration of a particle collecting device 1 for collecting particles from surfaces for a particle analysis when testing the technical cleanliness of test objects, in particular work pieces, machines and/or printed circuit boards, according to a preferred embodiment of the present invention.

[0040] Illustrated particle collecting device 1 comprises a cleaning unit 101, which is in operative contact with particle collecting device 1. Particle collecting device 1 comprises a first particle collection unit 120, which is a centrifugal separator 11, and a second particle collection unit 121, which is a filter holder 25, for a suction mode for aspirating a particle/air mixture from the surface of the test object. Filter holder 25 is configured for accommodating an exchangeable analysis filter; in suction mode, the particle/air mixture flows through the analysis filter before reaching a vacuum source 8 in order to deposit the particles on a particle collecting surface formed by the analysis filter.

[0041] Furthermore, cleaning unit 101 comprises an adapter unit 103, which is in operative contact with centrifugal separator 11 via a seat 100, which is a threaded connection 52. Adapter unit 103 comprises a connecting hose 105, which is schematically illustrated in the Figures and has a switchable valve 104, which can be switched between a fluid-conducting state and a fluid-blocking state. Connecting hose 105 is in fluid-conducting contact not only with adapter unit 103 but also with filter holder 25, which is why connecting hose 105 is in operative connection with vacuum source 8; in the case at hand, vacuum source 8 is formed by a wet vacuum cleaner 92.

[0042] Furthermore, illustrated cleaning unit 101 comprises a liquid storage unit 102, which is schematically illustrated in the Figures as a bucket, which contains a cleaning liquid for implementing the rinsing mode according to the invention.

[0043] When cleaning particle collecting device 1, suction line 12 is first immersed in the cleaning liquid of liquid storage unit 102. Then, valve 104 is switched into the fluid-blocking state to ensure that no cleaning liquid can flow via connecting hose 105.

[0044] Subsequently, the rinsing mode of particle collecting device 1 is activated by activating vacuum source 8; in the present embodiment of particle collecting device 1 according to the invention, vacuum source 8 is formed by a vacuum cleaner 92, as mentioned above. Switching on vacuum cleaner 92 causes suction line 12 to aspirate the cleaning liquid, which flows into centrifugal separator 11, from where it flows through filter holder 25, which does not comprise an analysis filter, via immersion tube 22 and the vacuum supply line.

[0045] Advantageously, the cleaning liquid flushes stuck and/or deposited particles out of the particle collecting device. After flowing through vacuum supply line 9 and filter holder 25, the cleaning liquid is collected in a storage unit (not shown) of vacuum cleaner 92.

[0046] Furthermore, various tests and measurements have shown that the advantageous use of adapter unit 103 makes a total amount of approximately 1 l of cleaning liquid sufficient in order to fully clean particle collecting device 1. In this context, it is to be advantageously noted that this means that multiple rinsing processes can be carried out for cleaning particle collecting device 1 before the storage unit formed by vacuum cleaner 92 is completely filled with the cleaning liquid. As a result, the rinsing mode can advantageously be implemented multiple times at any location between tests for determining the technical cleanliness.

[0047] After implementing the rinsing mode of particle collecting device 1, a dry mode of particle collecting device 1 is implemented, which is schematically illustrated in FIG. 1b.

[0048] For implementing the dry mode, which preferably follows immediately after the rinsing mode, vacuum cleaner 92 has to be deactivated first in order to end the suction mode or the rinsing mode. Then, a membrane suction end portion 106 is connected to the end of suction line 12 in such a manner that suction opening 62 of suction line 12 is completely covered by an air-permeable membrane 123 of membrane suction end portion 106.

[0049] After membrane suction end portion 106 has been connected in a suction-air-conducting manner, valve 104 is switched to the fluid-conducting state. Then, vacuum cleaner 92 is turned on to activate vacuum source 8.

[0050] Finely porous membrane 123 of membrane suction end portion 106 ensures that pure air only is aspirated by suction line 12 in dry mode of particle collecting device 1 since no additional particles can be aspirated from the environment through membrane 123. Furthermore, valve 104 of connecting hose 105 is switched to the fluid-conducting state in dry mode in order to form a fluid-conducting channel section 122. This has the result that cleaning liquid can also be suctioned off through connecting hose 105 in order to fully discharge the cleaning liquid backed up in centrifugal separator 11 because of the constructive design. In addition to the cleaning liquid backed up in centrifugal separator 11, any fluid residue is also discharged from particle collecting device 1 in dry mode, which is why a new suction mode for determining the technical cleanliness can be implemented immediately after ending the dry mode of particle collecting device 1 without the risk of humid particle clumps forming in particle collecting device 1 because of liquid residue.

[0051] FIGS. 2a and 2b show the particle collecting device 1 known from FIGS. 1a and 1 b, only suction line 12 and filter holder 25 being cleaned. Such a cleaning is advantageous whenever surfaces with few and/or small particles have been analyzed before since centrifugal separator 11, which is intended for filtering out large particles, is bypassed in a suction-air-conducting manner in suction mode in this case by connecting suction line 12 directly to filter holder 25 in a suction-air-conducting manner and not to centrifugal separator 11.

[0052] In this case, too, cleaning initially takes place in a rinsing mode, which is schematically illustrated in FIG. 2a and in which cleaning liquid is aspirated from a liquid storage unit 102 via suction line 12.

[0053] After implementing the rinsing mode, suction line 12 is also connected to membrane suction end portion 106, as schematically illustrated in FIG. 2b, in order to prevent a continued aspiration of particles from the environment in the subsequent dry mode.

[0054] As a result, the present invention allows a generic particle collecting device 1 to be cleaned thoroughly and quickly in a surprisingly simple manner; also, multiple cleanings of the particle collecting device can be carried out between measurements for determining the technical cleanliness in field use or in the case of an autarkic operation of particle collecting device 1.

REFERENCE SIGNS

[0055] 1 particle collecting device [0056] 8 vacuum source [0057] 9 vacuum supply line [0058] 11 centrifugal separator [0059] 12 suction line [0060] 22 immersion tube [0061] 25 filter holder [0062] 52 threaded connection [0063] 62 suction opening [0064] 92 vacuum cleaner [0065] 100 seat [0066] 101 cleaning unit [0067] 102 liquid storage unit [0068] 103 adapter unit [0069] 104 valve [0070] 105 connecting hose [0071] 106 membrane suction end portion [0072] 123 air-permeable membrane