METHOD FOR OPERATING A TREATMENT SYSTEM, TREATMENT SYSTEM, AND USE OF A TREATMENT SYSTEM

Abstract

The invention relates to a method for operating a treatment system, by means of which an optimized workpiece treatment is facilitated. The method for operating a treatment system comprises the following steps: guiding workpieces through a treatment basin filled with a treatment medium in order to treat the workpieces; rinsing the workpieces with a rinsing medium while and/or after the workpieces are removed from the treatment basin; and producing the rinsing medium from the treatment medium, wherein the rinsing medium is produced using a preparation device preferably by filtering, in particular nano-filtering, the treatment medium.

Claims

1. Method for operating a treatment system, comprising: guiding workpieces through a treatment basin filled with a treatment medium in order to treat the workpieces; rinsing the workpieces with a rinsing medium while and/or after the workpieces are removed from the treatment basin, wherein the rinsing medium is produced from the treatment medium.

2. Method according to claim 1, wherein the rinsing medium is produced by filtering, in particular nano-filtering, the treatment medium.

3. Method according to claim 2, wherein the treatment medium is separated into a permeate and a retentate by filtering, in particular nano-filtering, and wherein the permeate is used as a rinsing medium, in particular without any after-treatment of the permeate subsequent to the filtering.

4. Method according to claim 2, wherein the treatment medium is separated into a permeate and a retentate by filtering, in particular nano-filtering, and wherein the permeate is used as a rinsing medium, wherein at least approximately 50%, in particular at least approximately 75%, preferably at least approximately 95%, of the substances required for treating the workpieces are separated from the treatment medium during filtering, wherein the substances required for treating the workpieces preferably comprise one or more of the following substances: at least one organoalkoxysilane and/or at least one hydrolysis product and/or condensation product thereof, at least one zirconium compound, titanium compound, and/or hafnium compound, manganese ions, copper ions, and/or fluoride, in particular free fluoride.

5. Method according to claim 1, wherein the treatment medium is film-forming and comprises, as film-forming components, at least one zirconium compound, titanium compound, and/or hafnium compound, in particular at least one zirconium compound, and at least one organoalkoxysilane and/or at least one hydrolysis product and/or condensation product thereof, so that and/or wherein the treatment medium is or forms a zirconium oxide-based thin-film system.

6. Method according to claim 1, wherein an epoxy resin and/or phenolic resin for producing and/or forming a coating is produced using the treatment medium and/or wherein, using the treatment medium, the workpieces are provided with a film which comprises an epoxy resin and/or phenolic resin or is formed from an epoxy resin and/or phenolic resin.

7. Method according to claim 1, wherein the treatment medium has a pH value of at least approximately 4, in particular at least approximately 4.5, preferably at least approximately 5, prior to filtering, in particular nano-filtering, the same.

8. Method according to claim 1, wherein the treatment medium has a pH value of at most approximately 6, in particular at most approximately 5.5, preferably at most approximately 5, prior to filtering, in particular nano-filtering, the same.

9. Method according to claim 1, wherein the rinsing medium has a pH value of at least 4, in particular at least 4.5, preferably at least 5, prior to the application thereof onto the workpieces.

10. Method according to claim 1, wherein a flux of a membrane used for filtering, in particular nano-filtering, is at most approximately 50 l/m.sup.2 h, in particular at most approximately 35 l/m.sup.2 h.

11. Treatment system for treating workpieces, wherein the treatment system comprises: a treatment basin which is filled or can be filled with a treatment medium in order to treat the workpieces; a rinsing device for applying a rinsing medium to the workpieces; a preparation device for producing the rinsing medium from the treatment medium, wherein the rinsing medium is producible using the preparation device preferably by filtering, in particular nano-filtering, the treatment medium.

12. Treatment system according to claim 11, wherein the treatment system comprises two serially arranged pump devices for driving the treatment medium and/or the rinsing medium, wherein an intermediate filter device, in particular a cartridge filter device, is arranged between the two pump devices, and wherein at least one pump device is open-loop and/or closed-loop controllable by a control device in such a way that an increasing pressure drop in the intermediate filter device, which results from an increasing load factor of the intermediate filter device with increasing operating time, is compensated.

13. Treatment system according to either claim 11, wherein the preparation device comprises one or more membrane modules for filtering, in particular nano-filtering, the treatment medium, wherein the membrane modules, in particular parallel to one another, allow a passage of the treatment medium through them.

14. Treatment system according to claim 11, wherein the preparation device comprises one or more membrane modules for filtering, in particular nano-filtering, the treatment medium, wherein the membrane modules each comprise one or more thin-film composite membranes which preferably have an active separating layer made of polyamide and/or a MWCO (molecular weight cut-off) of at least 100 Da.

15. Treatment system according to claim 11, wherein the preparation device comprises a single pressure pipe stage.

16. Treatment system according to claim 11, wherein the preparation device comprises a pretreatment device which is arranged upstream of one or more membrane modules of the preparation device with respect to a flow direction of the treatment medium, wherein the pretreatment device comprises a separation device for separating particulate contents of the treatment medium.

17. Use of a treatment system according to claim 11 for carrying out a method according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0075] FIG. 1 is a schematic illustration of a treatment system in which a conventional rinsing device is provided; and

[0076] FIG. 2 is a schematic illustration of a treatment system corresponding to FIG. 1, in which a preparation device is provided for producing a rinsing medium from treatment medium.

[0077] Identical or functionally equivalent elements are provided with the same reference signs in all figures.

DETAILED DESCRIPTION OF THE DRAWINGS

[0078] A first embodiment, shown in FIG. 1, of a treatment system designated as a whole by 100 is, for example, an immersion treatment system 102 for treating workpieces 104.

[0079] The workpieces 104 are vehicle bodies 106, for example.

[0080] In particular, a protective layer, for example a corrosion protective layer, or some other coating can be applied to the workpiece 104 using the treatment system 100.

[0081] For this purpose, the treatment system 100 comprises a treatment basin 108 which is filled with a treatment medium 110 and into which the workpiece 104 can be immersed.

[0082] The treatment medium 110 is in particular a thin-film system for coating workpieces 104.

[0083] The thin-film system is in particular a zirconium oxide-based thin-film system.

[0084] If the workpieces 104 are now removed from the treatment basin 108, the use of such a thin-film system can in particular result in a more extensive coating of the workpiece 104 in the regions in which the treatment medium 110 still adheres to the workpiece 104, for example in the form of drops or runouts on a surface of the workpiece 104.

[0085] This can result in an impairment of the coating quality.

[0086] The treatment system 100 therefore preferably comprises a rinsing device 112, by means of which a rinsing medium 114 can be applied to the workpiece 104.

[0087] The rinsing medium 114 allows in particular an immediate removal of the treatment medium 110 from the workpiece 104 in order to stop a coating process immediately after the removal of the workpiece 104 from the treatment basin 108.

[0088] As a result, a mixture of rinsing medium 114 and treatment medium 110 is produced, which, depending on the composition of the treatment medium 110 and/or of the rinsing medium 114, may have to be disposed of or processed in a complex manner.

[0089] If the rinsing medium 114 together with the treatment medium 110 rinsed off from the workpiece 104 is simply introduced into the treatment basin 108, a dilution of the treatment medium 110 or some other chemically different composition of the treatment medium 110 can result, which can impair the treatment process.

[0090] A second embodiment of a treatment system 100 shown in FIG. 2 therefore preferably comprises a preparation device 116, by means of which rinsing medium 114 can be produced from the treatment medium 110.

[0091] In particular, the treatment medium 110 can be materially separated using the preparation device 116, in order in particular to separate off the film-forming components of the treatment medium 110. The treatment medium 110 which is at least approximately completely freed from the coating components can then be used as a rinsing medium 114.

[0092] Both parts separated from one another using the preparation device 116 can be brought together in the treatment basin 108, which results in a substantially constant composition of the treatment medium 110 in the treatment basin 108.

[0093] The preparation device 116 preferably comprises a pretreatment device 118 and/or an intermediate filter device 120.

[0094] Using the pretreatment device 118 and/or the intermediate filter device 120, it is possible, in particular, to separate particulate components, for example suspended matter, etc. from the treatment medium 110.

[0095] One or more membrane modules 122 of the preparation device 116, which separate a portion of the liquid that can be used as a rinsing medium 114 from the treatment medium 110, are preferably protected from coarse contamination using the pretreatment device 118 and/or the intermediate filter device 120.

[0096] The preparation device 116 preferably comprises a plurality of pump devices 124.

[0097] In particular, a pump device 124 is arranged upstream of the pretreatment device 118 and/or the intermediate filter device 120.

[0098] A further pump device 124 can be arranged downstream of the pretreatment device 118 and/or the intermediate filter device 120 and/or upstream of the one or more membrane modules 122.

[0099] Finally, a pump device 124 can be provided downstream of the one or more membrane modules 122, for example.

[0100] The pump devices 124 can in particular be open-loop and/or closed-loop controllable as a function of a differential pressure upstream or downstream of the one or more membrane modules 122.

[0101] In particular, a pressure difference that varies in the one or more membrane modules 122 due to varying impurities can be compensated by the pump device 124. In this way, a predetermined amount of rinsing medium can be reliably provided.

[0102] In the embodiment of the treatment system 100 shown in FIG. 2, a continuous, low-maintenance and efficient treatment operation preferably results.

[0103] In particular, only a small amount of additional treatment medium 110, liquid, for example fully desalinated water, and/or coating components of the treatment medium 110 is required, for example using a feed device 126, in order to maintain a continuous treatment operation.

[0104] It can be advantageous to maintain a predetermined pH value range of the treatment medium 110 and/or of the rinsing medium 114 so that the preparation device 116 reliably provides a medium that can be used as a rinsing medium 114. In particular, a nanofiltration membrane can be provided as the membrane in one or more membrane modules 122, which allows a pH value of the rinsing medium 114 of at least 4, for example at least 4.5, if the pH value of the treatment medium 110 is, for example, between approximately 4 and 5, and a retention of the film-forming components of the treatment medium 110 is at least approximately 60%, for example at least approximately 90%, in particular approximately 98%.

[0105] By maintaining the stated pH value range, it is possible in particular to prevent the rinsing medium 114 from loosening or otherwise damaging the coating adhering to the workpiece 104.

[0106] The preparation device 116 is preferably dimensioned and designed in such a way that a single pressure pipe stage is provided. In this way, the effort for chemical rinsing can preferably be reduced. In particular, a fully automatic mode of operation of the preparation device 116 is possible.

[0107] Incidentally, the second embodiment of the treatment system 100 shown in FIG. 2 corresponds in terms of structure and function to the embodiment shown in FIG. 1 so that reference is made to the above description. In further embodiments (not shown), any combination of features of the embodiments described above can be provided, optionally in combination with individual or multiple features of the introduction to the description.