EP1038992B1 - Process and apparatus for surface treatment of parts with a solvent - Google Patents

Process and apparatus for surface treatment of parts with a solvent Download PDF

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Publication number
EP1038992B1
EP1038992B1 EP00106230A EP00106230A EP1038992B1 EP 1038992 B1 EP1038992 B1 EP 1038992B1 EP 00106230 A EP00106230 A EP 00106230A EP 00106230 A EP00106230 A EP 00106230A EP 1038992 B1 EP1038992 B1 EP 1038992B1
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EP
European Patent Office
Prior art keywords
solvent
working chamber
solvent mixture
pressure
compressor
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EP00106230A
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German (de)
French (fr)
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EP1038992A1 (en
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Reiner Wolf
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Wolf GmbH
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Wolf GmbH
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Priority claimed from DE19939032A external-priority patent/DE19939032A1/en
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Publication of EP1038992A1 publication Critical patent/EP1038992A1/en
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    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23GCLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G5/00Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
    • C23G5/02Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23GCLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G5/00Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
    • C23G5/02Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents
    • C23G5/04Apparatus

Definitions

  • the invention relates to a method for the surface treatment of parts a solvent or a solvent mixture in a working chamber, especially for cleaning parts with the features of the preamble of Claim 1, and a system for performing the method, which an evaporator and a condenser to evaporate or condense of the solvent or of the solvent mixture, with the features the preamble of claim 14.
  • solvents containing chlorinated hydrocarbons such as perchlorethylene ( " Per") and trichlorethylene ( “ Tri"), with which the metal parts are rinsed, have long been used. Since these substances are both harmful to the environment and harmful to health, the metal parts are usually treated in a tightly closable working chamber, which is vented and ventilated via an adsorption / desorption unit.
  • the parts to be cleaned are placed, for example, in perforated boxes in the working chamber, where they are immersed in the solvent or solvent mixture and, if necessary, moved. After the cleaning process, the parts usually remain in the working chamber for drying so that only the smallest possible amount of solvent gets into the environment when the chamber is opened.
  • a method and an installation in which a solvent or solvent mixture in closed circuits, optionally leading through the working chamber is held and simultaneously by means of evaporation and subsequent Condensation can be prepared, the evaporation at a first, low pressure and condensing at a second, higher pressure is basically known from WO 93/17149.
  • the invention has for its object to be an inexpensive to implement Process for the surface treatment of parts, within the scope of which gentle and energy-efficient preparation of the solvent used or solvent mixture (which of course also includes water or a mixture on an aqueous basis) is possible, as well as a plant for implementation propose the method that enables energy savings and also manages with a few units or components, so that they can be manufactured inexpensively.
  • the method according to the invention keeps the solvent or solvent mixture in closed loops, being within these loops be processed by evaporation and subsequent condensation can, the evaporation at a first, low pressure and the condensation at a second, higher pressure occurs while the working chamber can be coupled into the circuits if necessary.
  • One of the circuits of the system according to the invention comprises an evaporator and a condenser for the solvent or solvent mixture as well a compressor arranged between them, the compressor one the first low pressure on the inlet side which acts on the evaporator and a second higher output side, which acts on the capacitor Generates pressure.
  • the working chamber is in this cycle if necessary be coupled.
  • the compressor can also with the appropriate design Function of the capacitor with take over what the expenditure on equipment decreases.
  • the energy efficiency of the method can be increased significantly if distilling the solvent or solvent mixture in two stages at different pressures is carried out: Due to the thermodynamic relationships, this is possible Solvent under low pressure at low temperatures in the gaseous State over, whereas it is under higher pressure at higher temperatures changes to the liquid state of matter; the energy requirement for that Evaporation decreases accordingly if this takes place at lower pressure, at the same time the cooling capacity required for the condensation is all the smaller can be, the higher the pressure prevailing in the condenser.
  • the solvent or solvent mixture for the invention Evaporation is heated the less the lower the pressure this place is.
  • the one that follows the proposed method essentially continuous preparation of the solvent or solvent mixture can therefore preferably be carried out more gently than one Distillation under atmospheric pressure.
  • the compressor located between the evaporator and the condenser the system according to the invention provides the necessary for the invention Pressure difference between evaporator and condenser on a particularly simple and efficient way.
  • the working chamber is, if necessary, in the solvent circuit coupled in, the parts to be treated rinsed with solvent be introduced into the chamber by adding fresh solvent and after the surface treatment of the parts brought into the working chamber on others Body is re-routed.
  • working chamber not narrowly defined: A working chamber in the sense of the invention can also be formed by the part to be cleaned itself, namely when it contains sealable cavities, the inner walls of which are cleaned should. These cavities function in the process according to the invention or the corresponding system as a working chamber.
  • the first, low pressure for evaporating the solvent is preferably or solvent mixture below atmospheric pressure, preferably between about 0.001 bar and 0.95 bar, while the second, higher Pressure for condensing above atmospheric pressure is preferred is between 2 bar and 15 bar, but in particular between 3 bar and 8 bar.
  • the evaporator can heated with the waste heat of the condenser and the condenser with that cooled evaporators coming from the evaporator are cooled.
  • the simultaneous heating of the evaporator by means of external heating and cooling the Condenser by means of usually electrically operated cooling unit thereby largely or even completely eliminated. This leads to significant energy savings, which especially with aqueous systems, in particular with Use of water as a solvent, due to the high specific Heat capacity of water considerably are. No separate means must be provided as the heat transfer medium because the condensate can serve as a heat carrier.
  • the invention offers further advantages in that the working chamber directly with freshly condensed and / or vaporous solvent or solvent mixture can be applied, if desired, even under high pressure. This has a positive effect on the cleaning result, since the purity of the so in the working chamber introduced solvent is very high and that in the previous State of the art, completely unknown, high operating pressure if necessary enables additional cleaning effects.
  • the first low pressure present according to the invention can be used. Because here the evaporation of the solvent or solvent mixture is made significantly easier due to the thermodynamic relationships the drying of the parts is advantageously quick.
  • the working chamber can be ventilated with ambient air after the surface treatment become. It is useful if the working chamber immediately afterwards is sucked off - preferably at the first, low pressure -, whereby Vapor the extracted air through an adsorption filter of solvent or solvent mixture is freed and in again for aeration the working chamber can be returned. By flushing the working chamber in this way can present a very low concentration of solvent vapors opening the working chamber can be achieved, which is when using CHC solvents is essential for occupational safety.
  • the adsorption filter required especially when using CHC solvents is preferably an activated carbon filter, which also with changing pressures can be applied:
  • the loading of the activated carbon with adsorbed solvents is significantly improved if the adsorption takes place at higher pressure, while the desorption required for the regeneration of the filter of solvents is significantly facilitated if this is lower Pressure is performed. Desorption is also supported when the filter is heated during this operation, for example by the waste heat of Compressor.
  • An activated carbon filter is particularly suitable for changing pressures which the activated carbon is introduced as a bed in a tube bundle. Here is the Activated carbon is also particularly easy to heat.
  • the system should be connected to a valve for emergency ventilation, if necessary to be able to reduce existing, high pressures in the shortest possible time; this emergency vent is preferably done via the adsorption filter to reduce environmental pollution or Minimize health risks even with emergency ventilation.
  • the compressor present in the system according to the invention is preferably a Liquid ring vacuum compressor with a rotary vane pump if required can be combined.
  • the liquid ring vacuum compressor outlines all from the fact that it is operated directly with the operating fluid and the Condensation in the operating fluid takes place.
  • the solvent or solvent mixture used is preferably essentially from water or aqueous cleaners. But it can also Chlorinated hydrocarbons, especially tetrachlorethylene and / or trichlorethylene can be used as the basis for the solvent or solvent mixture. in the Other solvents, e.g. modified Alcohols. In aqueous systems, however, the one according to the invention has an effect Energy saving is most obvious because water is approx. Evaporation energy required ten times higher than, for example, tetrachlorethylene.
  • the single figure shows a schematic representation of a preferred embodiment the system according to the invention. It is a system for Cleaning metal parts using a chlorinated hydrocarbon solvent. It mainly consists of a compressor 11, an evaporator 12, a working chamber 13, a reservoir 14, a condenser 15 and an adsorption filter 16. These units are via a piping system connected, the two filters 17a and 17b, the first tank 14a and one are assigned to a second tank 14b of the storage container 14, a measuring computer 38 and contains a number of valves 19 to 37. When operating such a system with aqueous solvents, the adsorption filter 16 can be omitted.
  • the evaporator 12 and the condenser 15 are with a separate piping system connected for a heat transfer circuit, the support heater 45th for the evaporator 12, a pump 46 and a cooler 47 for the condenser 15 has.
  • the heat transfer medium used is preferably water.
  • the evaporator 12 is for continuous evaporation of the solvent provided under vacuum, at pressures from 0.01 to 0.95 bar. impurities the solvent, such as lubricants, accumulate in the bottom of the evaporator 12 on and can be drained or distilled separately if necessary.
  • the continuous evaporation under vacuum can be essential at one lower temperature than under atmospheric pressure, which on the one hand for the solvent is very gentle and on the other hand enables the evaporator 12 to operate with the waste heat of the capacitor 15. The solvent vapor is sucked in by the compressor 11.
  • the compressor 11 is a combination of a rotary vane pump and a liquid ring vacuum compressor, for continuous, multi-level compression of solvent vapors, if necessary with the addition of air is. For example, it generates a vacuum of up to 10 mbar and an overpressure of approx. 6 bar on the output side.
  • the compressed solvent vapor via a controlled three-way valve 18 either the adsorption filter 16, the condenser 15 or, controlled by the valve 23, equal to the reservoir 14 fed.
  • the condenser 15 is designed as a pressure vessel. Cooling the condenser 15 takes place via the separate heat transfer circuit with that in the evaporator 12 cooled water; if necessary, the water in the cooler 47 is previously further cooled down.
  • the solvent vapor is in the condenser 15 at pressures condensed from about 3 to 8 bar. This condenses due to the high pressure Solvent at a higher dew point temperature than under atmospheric pressure out. As a result, the water coming from the evaporator 12 is sufficient to cool the Condensate normally.
  • the condensate is in a droplet separator 39 collected and from any water that is present, in particular through Humidity occurs separately. Then the condensed solvent either via the controlled valve 24 in the reservoir 14 or passed directly into the working chamber 13 via the controlled valve 22.
  • the working chamber 13 is designed as a pressure vessel, for example with a rotatable and swiveling basket holder, in which a work basket is added is (not shown in the drawing).
  • the metal parts to be cleaned are from Hand or with an automatic loading device, preferably in Hole boxes introduced into the working chamber 13 and this by means of a sliding door 41 closed.
  • the sliding door 41 is preferred equipped with a toggle lock.
  • Liquid solvent can flow through the valve 28 from the reservoir 14, and via the valve 27 can optionally freshly condensed liquid solvent from the condenser 15, solvent vapor from the compressor 11 or purified air from the adsorption filter 16 are introduced into the working chamber 13.
  • the valve 29 enables direct Ventilation of the working chamber 13 with ambient air. Via an outlet 42 at the bottom of the working chamber 13 can solvent after the cleaning process removed from the working chamber and via the valves 30 and 31 into the reservoir 14 are directed.
  • the valve 26 finally enables a direct connection the working chamber 13 to the inlet side of the compressor 11.
  • the reservoir 14 is formed in two parts, with a first tank 14a and a second tank 14b, which are separated from one another by an overflow 44.
  • the tanks 14a and 14b are removed from the working chamber 13 in the general contaminated solvent.
  • the second tank 14b via the valve 24 fresh condensate from the condenser 15 and - for pressurization - via the valve 23 solvent vapor directly the compressor 11 are initiated. That from the second tank 14b to the first Solvent overflowing in tank 14a dilutes the solvents heated by a tank heater 43. Via the valves 34 and 28 or 35 and 28 can over liquid solvent from the tank 14a or 14b a filter 17a or 17b are pressed into the working chamber 13.
  • About the controlled Valve 32 can be the evaporator 12 liquid solvent or Evacuation of reservoir 14 - solvent vapor from the first tank 14a. There is also liquid solvent from the tanks 14a and 14b via the filters 17a and 17b and via the valves 36 and 37 into the evaporator 12 transferable.
  • the adsorption filter 16 (only required in CHC systems) is finally as Pressure vessel with an activated carbon fixed bed designed as an adsorbent.
  • the activated carbon is located as a bed in tube bundles 40.
  • the adsorption filter 16 is under pressure, whereby the absorption capacity of the activated carbon increases considerably.
  • the adsorption filter 16 is via the two three-way valves 18 and 21 directly to the compressor 11 connectable, so that it is either pressurized or vacuum can be:
  • the regeneration of the activated carbon takes place under vacuum, if necessary with additional heating of the activated carbon with the waste heat from the compressor 11 via a heating tube 48, which considerably accelerates the desorption of the solvent becomes.
  • the adsorption filter 16 can be reversed of the three-way valve 21 are connected to the condenser 15. About the Valves 27 and 20, the adsorption filter 16 can be connected to the working chamber 13, so that there passed through the adsorption filter 16 of solvent vapors cleaned air can be introduced.
  • Liquid solvent is filled into the storage container 14 via the valves 36 and 37 also reaches the evaporator 12.
  • the compressor 11 is started and the valve 33 opened so that the evaporator 12 is evacuated.
  • the pump 46 which serves to circulate the heat transfer medium water, and the auxiliary heater 45 are put into operation.
  • the water heated by the auxiliary heater 45 becomes passed through the evaporator 12, causing the liquid solvent therein evaporates and is sucked in by the compressor 11.
  • the compressor 11 compresses the suctioned solvent vapor to a pressure of approx. 3 to 8 bar. If necessary, additional air can be supplied via the valves 26 and 29.
  • the solvent vapor compressed by the compressor 11 is opened by opening the Valves 18 and 23 passed into the reservoir 14. This will result in the reservoir 14 generates an overpressure, for example with approximately 5 bar.
  • the valve 32 remains closed.
  • valves 34 and 28 By opening valves 34 and 28, liquid solvent is removed from the tank 14a pressed into the working chamber 13, since these are loaded with metal parts and the closing of the sliding door 41 is still under atmospheric pressure. In this way, rough impurities of the solvent are retained in the filter 17a. In order to flood the working chamber 13 with solvent, it can are vented to the compressor 11 via the valve 26.
  • the metal parts arranged in a work basket in the work chamber 13 are undergo primary cleaning by spraying liquid solvent.
  • a level controller (not shown) Metal parts cleaned in the immersion bath. This is preferably done under rotation and Swiveling movements of the basket in the solvent bath.
  • the one present in the storage container 14 becomes Overpressure is released via valve 32 and, if necessary, a vacuum is generated. Then the valve 30 is opened and the working chamber 13 via the Valves 19, 20 and 27 are vented so that the solvent flows into the tank 14a.
  • the compressor 11 takes care of the generation of the transport operations pressure differences used for processing the solvent, by compressing the solvent vapor drawn from the evaporator 12 conducts into the condenser 15 via the valve 18.
  • the capacitor 15 will of the water cooled in the evaporator 12, its temperature if necessary is further lowered by the additional cooler 47, cooled; the waste heat of the In turn, capacitor 15 provides for heating the evaporator 12. If the excess pressure generated by the compressor 11 in the reservoir 14 is no longer required can be fresh by closing the valve 23 and opening the valve 24 condensed solvent from the condenser 15 into the storage container 14 be initiated by means of a pressure difference. So the solvent becomes continuous distilled.
  • the freshly condensed solvent can be closed by closing valves 23 and 24 and opening the valve 22 directly and preferably under high pressure (originating from the compressor 11) passed into the working chamber 13 and sprayed there, for example become.
  • the required venting of the working chamber 13 takes place via the valve 26.
  • the condensate is of high purity, which makes it primarily suitable for the post-cleaning of the metal parts is suitable.
  • Solvent vapor can be drawn directly from the compressor via the valves 18, 23, 30 and 31 11 are passed into the working chamber, preferably under high pressure. Here, too, any necessary ventilation of the working chamber 13 takes place via valve 26. This high pressure steam rinsing is suitable for a final Fine cleaning of the metal parts and / or for heating them to a accelerate subsequent drying.
  • valve 26 the compressor 11 evacuates solvent vapor and air has entered the working chamber 13 by the loading. After reaching one Minimum pressure, valve 27 is opened at the end of the drying process, so that outside air is brought into the working chamber until atmospheric pressure is reached 13 streams.
  • the working chamber 13 is opened by opening the valves 19, 20, 26 and 27 with ambient air rinsed.
  • the solvent concentration is monitored during the air purge in that the solvent vapor / air mixture drawn off by the compressor 11 from the working chamber 13 is passed through the measuring computer 38 via the valve 25.
  • the measuring computer 38 only releases the sliding door 41 of the working chamber 13 when the prescribed limit of the solvent concentration was undershot becomes.
  • Process steps (g), (h) and (i) are in the present example one with CHC solvents operated system makes sense; when operating a system with aqueous These process steps are easily dispensable for solvents.

Abstract

Solvent treatment of parts involves using closed circuits in which solvent is regenerated by low pressure evaporation and high pressure condensation. Surface treatment of parts is carried out using a solvent or solvent mixture maintained in closed circuits which optionally pass through the treatment chamber and which regenerate the solvent by evaporation at low pressure and condensation at high pressure. An Independent claim is also included for an installation for carrying out the above process. Preferred Features: The low pressure is below atmospheric pressure, especially 0.001-0.95 bars, and the high pressure is above atmospheric pressure, preferably 2-15 (especially 3-8) bars The solvent may be water or an aqueous mixture.

Description

Die Erfindung betrifft ein Verfahren zur Oberflächenbehandlung von Teilen mit einem Lösungsmittel oder einem Lösungsmittelgemisch in einer Arbeitskammer, insbesondere zur Reinigung von Teilen mit den Merkmalen des Oberbegriffs des Patentanspruchs 1, sowie eine Anlage zur Durchführung des Verfahrens, welche einen Verdampfer und einen Kondensator zum Verdampfen bzw. Kondensieren des Lösungsmittels oder des Lösungsmittelgemischs umfaßt, mit den Merkmalen des Oberbegriffs des Patentanspruchs 14.The invention relates to a method for the surface treatment of parts a solvent or a solvent mixture in a working chamber, especially for cleaning parts with the features of the preamble of Claim 1, and a system for performing the method, which an evaporator and a condenser to evaporate or condense of the solvent or of the solvent mixture, with the features the preamble of claim 14.

Insbesondere zur Entfettung von Metallteilen werden seit längerem chlorkohlenwasserstoffhaltige Lösungsmittel eingesetzt, wie beispielsweise Perchlorethylen ("Per") und Trichlorethylen ("Tri"), mit welchen die Metallteile gespült werden. Da diese Stoffe sowohl umweltschädigend als auch gesundheitsschädlich sind, erfolgt die Behandlung der Metallteile üblicherweise in einer dicht verschließbaren Arbeitskammer, die über eine Adsorptions-/Desorptionseinheit entlüftet und belüftet wird. Die zu reinigenden Teile werden beispielsweise in Lochkästen in die Arbeitskammer eingebracht und dort in das Lösungsmittel oder Lösungsmittelgemisch eingetaucht sowie gegebenenfalls bewegt. Nach dem Reinigungsvorgang verbleiben die Teile üblicherweise noch zur Trocknung in der Arbeitskammer, damit beim Öffnen der Kammer nur eine möglichst geringe Menge an Lösungsmittel in die Umgebung gelangt.For the degreasing of metal parts, solvents containing chlorinated hydrocarbons, such as perchlorethylene ( " Per") and trichlorethylene ( " Tri"), with which the metal parts are rinsed, have long been used. Since these substances are both harmful to the environment and harmful to health, the metal parts are usually treated in a tightly closable working chamber, which is vented and ventilated via an adsorption / desorption unit. The parts to be cleaned are placed, for example, in perforated boxes in the working chamber, where they are immersed in the solvent or solvent mixture and, if necessary, moved. After the cleaning process, the parts usually remain in the working chamber for drying so that only the smallest possible amount of solvent gets into the environment when the chamber is opened.

Aus der DE-Zeitschrift "JOT 1997/3", Seiten 48 bis 52, ist beispielsweise eine Anlage zur Oberflächenbehandlung von Teilen mit Chlorkohlenwasserstoffen bekannt, bei welcher die zu behandelnden Teile in eine Arbeitskammer eingebracht werden und diese dann mit flüssigen Chlorkohlenwasserstoffen geflutet wird. Nach dem Reinigungsvorgang wird das Lösungsmittel in einen Vorratstank abgelassen und der Reinigungsvorgang gegebenenfalls wiederholt. Zur anschließenden Trocknung der gereinigten Metallteile wird die Arbeitskammer evakuiert, und abgesogene Lösungsmitteldämpfe werden zum größten Teil in einem Kondensator auskondensiert sowie in den Vorratstank zurückgeführt. Die aus der Arbeitskammer abgesogene Luft mit ihrem Restgehalt an Lösungsmitteldämpfen wird nicht über eine Adsorptions-/Desorptionseinheit aus der Anlage ausgeleitet, sondern in einem Volumenpuffer zwischengespeichert und zur späteren (Wieder-)Belüftung der Arbeitskammer verwendet. Zur regelmäßigen Aufbereitung des Lösungsmittels durch Destillation umfaßt diese bekannte Anlage außerdem einen Verdampfer mit nachgeschaltetem Kondensator.From the DE magazine "JOT 1997/3", pages 48 to 52, for example, one Plant for surface treatment of parts with chlorinated hydrocarbons known in which the parts to be treated are introduced into a working chamber are then flooded with liquid chlorinated hydrocarbons becomes. After the cleaning process, the solvent is placed in a storage tank drained and the cleaning process repeated if necessary. To the subsequent one Drying of the cleaned metal parts, the working chamber is evacuated, and drawn solvent vapors are largely in one Condenser condensed out and returned to the storage tank. The Air extracted from the working chamber with its residual content of solvent vapors does not have an adsorption / desorption unit from the system derived, but buffered in a volume buffer and for later (Re) ventilation of the working chamber used. For regular preparation of the solvent by distillation comprises this known plant also an evaporator with a downstream condenser.

Ein Verfahren und eine Anlage, in der ein Lösungsmittel oder Lösungsmittelgemisch in geschlossenen, wahlweise durch die Arbeitskammer führenden Kreisläufen gehalten wird und gleichzeitig mittels Verdampfen und anschließendem Kondensieren aufbereitet werden kann, wobei das Verdampfen bei einem ersten, niedrigen Druck und das Kondensieren bei einem zweiten, höheren Druck erfolgt, ist grundsätzlich aus der WO 93/17149 bekannt.A method and an installation in which a solvent or solvent mixture in closed circuits, optionally leading through the working chamber is held and simultaneously by means of evaporation and subsequent Condensation can be prepared, the evaporation at a first, low pressure and condensing at a second, higher pressure is basically known from WO 93/17149.

Der Erfindung liegt die Aufgabe zugrunde, ein kostengünstig zu realisierendes Verfahren zur Oberflächenbehandlung von Teilen, in dessen Rahmen eine schonende und energieeffiziente Aufbereitung des verwendeten Lösungsmittels oder Lösungsmittelgemischs (das selbstverständlich auch Wasser oder ein Gemisch auf wässriger Basis sein kann) möglich ist, sowie eine Anlage zur Durchführung des Verfahrens vorzuschlagen, die eine Energieeinsparung ermöglicht und außerdem mit wenigen Aggregaten bzw. Bauteilen auskommt, so daß sie kostengünstig gefertigt werden kann.The invention has for its object to be an inexpensive to implement Process for the surface treatment of parts, within the scope of which gentle and energy-efficient preparation of the solvent used or solvent mixture (which of course also includes water or a mixture on an aqueous basis) is possible, as well as a plant for implementation propose the method that enables energy savings and also manages with a few units or components, so that they can be manufactured inexpensively.

Diese Aufgabe wird erfindungsgemäß durch ein Verfahren mit den Merkmalen des beigefügten Patentanspruchs 1 sowie durch eine Anlage mit den Merkmalen des beigefügten Patentanspruchs 14 gelöst.This object is achieved according to the invention by a method with the features of the appended claim 1 and by a system with the features of the attached claim 14 solved.

Vorteilhafte Weiterbildungen des Verfahrens sind in den Ansprüchen 2 bis 13 niedergelegt, bevorzugte Ausgestaltungen der erfindungsgemäßen Anlage ergeben sich aus den Ansprüchen 15 bis 28. Advantageous developments of the method are in claims 2 to 13 deposited, preferred configurations of the system according to the invention result themselves from claims 15 to 28.

Das Verfahren nach der Erfindung hält das Lösungsmittel oder Lösungsmittelgemisch in geschlossenen Kreisläufen, wobei es innerhalb dieser Kreisläufe mittels Verdampfen und anschließendem Kondensieren aufbereitet werden kann, wobei das Verdampfen bei einem ersten, niedrigen Druck und das Kondensieren bei einem zweiten, höheren Druck erfolgt, während die Arbeitskammer bedarfsweise in die Kreisläufe einkoppelbar ist.The method according to the invention keeps the solvent or solvent mixture in closed loops, being within these loops be processed by evaporation and subsequent condensation can, the evaporation at a first, low pressure and the condensation at a second, higher pressure occurs while the working chamber can be coupled into the circuits if necessary.

Einer der Kreisläufe der erfindungsgemäßen Anlage umfaßt einen Verdampfer und einen Kondensator für das Lösungsmittel oder Lösungsmittelgemisch sowie einen zwischen diesen angeordneten Verdichter, wobei der Verdichter einen eingangsseitigen, den Verdampfer beaufschlagenden, ersten niedrigen Druck und einen ausgangsseitigen, den Kondensator beaufschlagenden, zweiten höheren Druck erzeugt. Die Arbeitskammer ist bedarfsweise in diesen Kreislauf einkoppelbar. Der Verdichter kann bei entsprechender Ausgestaltung auch die Funktion des Kondensators mit übernehmen, was den apparativen Aufwand mindert.One of the circuits of the system according to the invention comprises an evaporator and a condenser for the solvent or solvent mixture as well a compressor arranged between them, the compressor one the first low pressure on the inlet side which acts on the evaporator and a second higher output side, which acts on the capacitor Generates pressure. The working chamber is in this cycle if necessary be coupled. The compressor can also with the appropriate design Function of the capacitor with take over what the expenditure on equipment decreases.

Erfindungsgemäß ist erkannt worden, daß die Energieeffizienz des Verfahrens ganz wesentlich erhöht werden kann, wenn das Destillieren des Lösungsmittels oder Lösungsmittelgemischs in zwei Stufen bei unterschiedlichen Drücken durchgeführt wird: Aufgrund der thermodynamischen Zusammenhänge geht das Lösungsmittel unter geringem Druck bei niedrigen Temperaturen in den gasförmigen Zustand über, wohingegen es unter höherem Druck bei höheren Temperaturen in den flüssigen Aggregatzustand wechselt; der Energiebedarf für das Verdampfen sinkt dementsprechend, wenn dieses bei geringerem Druck erfolgt, wobei gleichzeitig die für das Kondensieren benötigte Kühlleistung um so kleiner sein kann, je höher der im Kondensator herrschende Druck ist.According to the invention, it has been recognized that the energy efficiency of the method can be increased significantly if distilling the solvent or solvent mixture in two stages at different pressures is carried out: Due to the thermodynamic relationships, this is possible Solvent under low pressure at low temperatures in the gaseous State over, whereas it is under higher pressure at higher temperatures changes to the liquid state of matter; the energy requirement for that Evaporation decreases accordingly if this takes place at lower pressure, at the same time the cooling capacity required for the condensation is all the smaller can be, the higher the pressure prevailing in the condenser.

Ferner muß das Lösungsmittel oder Lösungsmittelgemisch zum erfindungsgemäßen Verdampfen um so weniger erhitzt werden, je niedriger der Druck an dieser Stelle ist. Die nach dem vorgeschlagenen Verfahren erfolgende, im wesentlichen kontinuierliche Aufbereitung des Lösungsmittels oder Lösungsmittelgemischs kann also vorzugsweise schonender vorgenommen werden, als eine Destillation unter atmosphärischem Druck. Furthermore, the solvent or solvent mixture for the invention Evaporation is heated the less the lower the pressure this place is. The one that follows the proposed method, essentially continuous preparation of the solvent or solvent mixture can therefore preferably be carried out more gently than one Distillation under atmospheric pressure.

Der zwischen dem Verdampfer und dem Kondensator angeordnete Verdichter der erfindungsgemäßen Anlage stellt den für die Erfindung erforderlichen Druckunterschied zwischen Verdampfer und Kondensator auf besonders einfache und effiziente Weise her.The compressor located between the evaporator and the condenser the system according to the invention provides the necessary for the invention Pressure difference between evaporator and condenser on a particularly simple and efficient way.

Die Arbeitskammer wird nach der Erfindung bedarfsweise in den Lösungsmittelkreislauf eingekoppelt, wobei die zu behandelnden Teile mit Lösungsmittel gespült werden, indem frisches Lösungsmittel in die Kammer eingeleitet und nach der Oberflächenbehandlung der in die Arbeitskammer verbrachten Teile an anderer Stelle wieder ausgeleitet wird. Hierbei ist der Begriff "Arbeitskammer" nicht eng definiert: Eine Arbeitskammer im Sinne der Erfindung kann durchaus auch durch das zu reinigende Teil selbst gebildet werden, nämlich dann, wenn es abdichtbare Hohlräume enthält, deren Innenwandungen gereinigt werden sollen. Diese Hohlräume fungieren im Rahmen des erfindungsgemäßen Verfahrens bzw. der entsprechenden Anlage dann als Arbeitskammer.According to the invention, the working chamber is, if necessary, in the solvent circuit coupled in, the parts to be treated rinsed with solvent be introduced into the chamber by adding fresh solvent and after the surface treatment of the parts brought into the working chamber on others Body is re-routed. Here the term "working chamber" not narrowly defined: A working chamber in the sense of the invention can also be formed by the part to be cleaned itself, namely when it contains sealable cavities, the inner walls of which are cleaned should. These cavities function in the process according to the invention or the corresponding system as a working chamber.

Bevorzugterweise liegt der erste, niedrige Druck für das Verdampfen des Lösungsmittels oder Lösungsmittelgemischs unterhalb des Atmosphärendrucks, vorzugsweise zwischen etwa 0,001 bar und 0,95 bar, während der zweite, höhere Druck für das Kondensieren oberhalb des Atmosphärendrucks vorzugsweise zwischen 2 bar und 15 bar, insbesondere jedoch zwischen 3 bar und 8 bar liegt. Die Vorteile der Erfindung gegenüber dem bisherigen Stand der Technik, in welchem üblicherweise bei Atmosphärendruck gearbeitet wird, kommen dann besonders vorteilhaft zum Tragen: Insbesondere der Siedepunkt des Lösungsmittels oder Lösungsmittelgemischs liegt dann niedriger als bisher üblich, so daß nicht nur beim Heizen des Verdampfers Energie eingespart werden kann, sondern auch eine wesentlich schonendere Aufbereitung der Lösungsmitel resultiert. Umgekehrt verhält es sich beim Kondensieren des Lösungsmittels oder Lösungsmittelgemischs; hier ist die Kondensationstemperatur gegenüber dem bisher Bekannten deutlich erhöht, so daß zum einen der Aufwand für die Kühlung des Kondensators deutlich kleiner wird und zum anderen das Lösungsmittel oder Lösungsmittelgemisch nicht mehr so stark heruntergekühlt werden muß; die Temperaturunterschiede sind insgesamt viel geringer.The first, low pressure for evaporating the solvent is preferably or solvent mixture below atmospheric pressure, preferably between about 0.001 bar and 0.95 bar, while the second, higher Pressure for condensing above atmospheric pressure is preferred is between 2 bar and 15 bar, but in particular between 3 bar and 8 bar. The advantages of the invention over the prior art, in which Usually working at atmospheric pressure is particularly important advantageous to wear: especially the boiling point of the solvent or solvent mixture is then lower than usual so far not only can energy be saved when heating the evaporator, but also This also results in a much gentler preparation of the solvents. The reverse is true when condensing the solvent or Solvent mixture; here is the condensation temperature compared to that previously known significantly increased, so that on the one hand the cost of cooling of the capacitor becomes significantly smaller and secondly the solvent or solvent mixture no longer needs to be cooled down as much; the overall temperature differences are much smaller.

Im Rahmen der Erfindung ist vorgesehen, für das Verdampfen des Lösungsmittels oder Lösungsmittelgemischs zumindest teilweise die beim Kondensieren erzeugte Wärme zu verwenden. Wenn man einen Wärmeträgerkreislauf zwischen dem Verdampfer und dem Kondensator einrichtet, kann der Verdampfer mit der Abwärme des Kondensators erhitzt und der Kondensator mit dem aus dem Verdampfer kommenden, abgekühlten Wärmeträger gekühlt werden. Das gleichzeitige Erhitzen des Verdampfers mittels Fremdheizung und Kühlen des Kondensators mittels üblicherweise elektrisch betriebenem Kühlaggregat kann dadurch größtenteils oder gar ganz entfallen. Dies führt zu signifikanten Energieeinsparungen, die vor allem bei wässrigen Systemen, also insbesondere bei Verwendung von Wasser als Lösungsmittel, aufgrund der hohen spezifischen Wärmekapazität von Wasser beträchtlich sind. Als Wärmeträger muß hierbei kein separates Mittel bereitgestellt werden, denn das Kondensat kann hier als Wärmeträger dienen.Within the scope of the invention it is provided for the evaporation of the solvent or solvent mixture at least partially that when condensing to use generated heat. If you have a heat transfer circuit between sets up the evaporator and the condenser, the evaporator can heated with the waste heat of the condenser and the condenser with that cooled evaporators coming from the evaporator are cooled. The simultaneous heating of the evaporator by means of external heating and cooling the Condenser by means of usually electrically operated cooling unit thereby largely or even completely eliminated. This leads to significant energy savings, which especially with aqueous systems, in particular with Use of water as a solvent, due to the high specific Heat capacity of water considerably are. No separate means must be provided as the heat transfer medium because the condensate can serve as a heat carrier.

Insbesondere im Anfahrbetrieb der erfindungsgemäßen Anlage kann es dennoch sinnvoll sein, eine zusätzliche Stützheizung für den Verdampfer und/oder einen zusätzlichen Kühler für den Kondensator einzusetzen.In particular when starting up the system according to the invention, it can nevertheless be useful, an additional support heater for the evaporator and / or use additional cooler for the condenser.

Weitere, erhebliche Vorteile ergeben sich, wenn der Transport des Lösungsmittels oder Lösungsmittelgemischs innerhalb der entsprechenden Anlage mittels der im Kreislauf herrschenden Druckunterschiede erfolgt. Zusätzliche Pumpen entfallen hierdurch; der Transport und die Steuerung des Lösungsmittelflusses erfolgt dann nur noch durch entsprechendes Steuern von Ventilen. Wenn ein zwischen dem Verdampfer und dem Kondensator angeordneter Verdichter für den erfindungsgemäßen Druckunterschied sorgt, entfallen Flüssigkeitspumpen für den Betrieb der erfindungsgemäßen Anlage sogar ganz: Der Verdichter ist in einem Abschnitt der Anlage angebracht, in welchem das Lösungsmittel oder Lösungsmittelgemisch in gasförmigem Aggregatzustand vorliegt. Der apparative Aufwand für die gesamte Anlage wird hierdurch vermindert; auch die Rohrquerschnitte für den Lösungsmitteltransport können vorteilhaft klein gehalten sein.Further, significant advantages arise when transporting the solvent or solvent mixture within the corresponding system by means of the Circulation prevailing pressure differences takes place. Additional pumps are not required therethrough; the transport and control of the solvent flow then takes place only by controlling valves accordingly. If a between Evaporator and the condenser arranged compressor for the invention Pressure difference, liquid pumps are no longer required for the operation of the Plant according to the invention even completely: The compressor is in a section of the Plant attached in which the solvent or solvent mixture in gaseous state of matter is present. The equipment effort for the whole Plant is thereby reduced; also the pipe cross-sections for solvent transport can advantageously be kept small.

Vor allem dann, wenn der vom Verdichter erzeugte erste, niedrige Druck unterhalb und der zweite, höhere Druck oberhalb des Atmosphärendrucks liegt, ergeben sich im Zusammenspiel mit einer Belüftung bzw. Entlüftung der Arbeitskammer mit Umgebungsluft (bei Atmosphärendruck) vorteilhafte Möglichkeiten des Lösungsmitteltransports. Insbesondere hierbei hat es sich als zweckmäßig erwiesen, wenn mindestens ein Vorratsbehälter für das Lösungsmittel oder Lösungsmittelgemisch vorhanden ist, über den die Ankopplung der Arbeitskammer in den Lösungsmittelkreislauf erfolgt. Dieser Vorratsbehälter kann unter wechselnden Drücken betrieben werden: So kann er beispielsweise beim Einleiten von Lösungsmittel in die Arbeitskammer mit dem zweiten, höheren Druck und beim Rückfließen des Lösungsmittels in den Vorratsbehälter mit dem ersten, niedrigen Druck beaufschlagt werden, welche dann beide einen Druckunterschied zum wahlweise in der Arbeitskammer herrschenden Atmosphärendruck erzeugen. Especially when the first low pressure generated by the compressor is below and the second, higher pressure is above atmospheric pressure in interaction with ventilation of the working chamber with ambient air (at atmospheric pressure) advantageous possibilities of solvent transport. In particular, it has proven to be useful if at least a storage container for the solvent or solvent mixture is available is via which the coupling of the working chamber into the solvent circuit he follows. This reservoir can operate under changing pressures For example, when introducing solvent into the Working chamber with the second, higher pressure and when the solvent flows back into the reservoir with the first, low pressure which then both have a pressure difference to either in the working chamber generate prevailing atmospheric pressure.

Zur Grobreinigung des Lösungsmittels oder Lösungsmittelgemischs ist es zweckmäßig, mindestens einen Filter vorzusehen, durch den das Lösungsmittel hindurch geleitet wird. Vor allem Feststoffverunreinigungen wie Metallspäne oder dergleichen sind auf diese Weise am einfachsten aus dem Lösungsmittelkreislauf zu entfernen.For rough cleaning of the solvent or solvent mixture, it is advisable to to provide at least one filter through which the solvent passes is directed. Above all, solid contaminants such as metal chips or the like are the easiest way to remove them from the solvent circuit.

Weitere Vorteile bietet die Erfindung dadurch, daß die Arbeitskammer direkt mit frisch kondensiertem und/oder dampfförmigem Lösungsmittel oder Lösungsmittelgemisch beaufschlagt werden kann, wenn gewünscht, sogar unter hohem Druck. Dies wirkt sich positiv auf das Reinigungsergebnis aus, da die Reinheit des so in die Arbeitskammer eingebrachten Lösungsmittels sehr hoch ist und der im bisherigen Stand der Technik noch völlig unbekannte, hohe Betriebsdruck gegebenenfalls zusätzliche Reinigungseffekte ermöglicht.The invention offers further advantages in that the working chamber directly with freshly condensed and / or vaporous solvent or solvent mixture can be applied, if desired, even under high pressure. This has a positive effect on the cleaning result, since the purity of the so in the working chamber introduced solvent is very high and that in the previous State of the art, completely unknown, high operating pressure if necessary enables additional cleaning effects.

Für die Trocknung der oberflächenbehandelten Teile in der Arbeitskammer kann wiederum der erfindungsgemäß vorhandene, erste, niedrige Druck verwendet werden. Da hier die Verdampfung des Lösungsmittels oder Lösungsmittelgemischs aufgrund der thermodynamischen Zusammenhänge deutlich erleichtert ist, erfolgt die Trocknung der Teile vorteilhaft schnell.For drying the surface-treated parts in the working chamber again the first low pressure present according to the invention can be used. Because here the evaporation of the solvent or solvent mixture is made significantly easier due to the thermodynamic relationships the drying of the parts is advantageously quick.

Die Arbeitskammer kann nach der Oberflächenbehandlung mit Umgebungsluft belüftet werden. Hierbei ist es zweckmäßig, wenn die Arbeitskammer gleich anschließend abgesaugt wird - vorzugsweise beim ersten, niedrigen Druck -, wobei die abgesaugte Luft über einen Adsorptionsfilter von Lösungsmittel- oder Lösungsmittelgemischdämpfen befreit wird und für eine erneute Belüftung wieder in die Arbeitskammer zurückgeführt werden kann. Durch ein solches Spülen der Arbeitskammer kann eine sehr niedrige Konzentration von Lösungsmitteldämpfen vor dem Öffnen der Arbeitskammer erreicht werden, was bei Verwendung von CKW-Lösungsmitteln für die Arbeitssicherheit unerläßlich ist.The working chamber can be ventilated with ambient air after the surface treatment become. It is useful if the working chamber immediately afterwards is sucked off - preferably at the first, low pressure -, whereby Vapor the extracted air through an adsorption filter of solvent or solvent mixture is freed and in again for aeration the working chamber can be returned. By flushing the working chamber in this way can present a very low concentration of solvent vapors opening the working chamber can be achieved, which is when using CHC solvents is essential for occupational safety.

Der insbesondere bei Verwendung von CKW-Lösungsmitteln erforderliche Adsorptionsfilter ist vorzugsweise ein Aktivkohlefilter, der ebenfalls mit wechselnden Drücken beaufschlagt werden kann: Die Beladung der Aktivkohle mit adsorbierten Lösungsmitteln wird deutlich verbessert, wenn die Adsorption bei höherem Druck erfolgt, während die zur Regeneration des Filters turnusmäßig notwendige Desorption von Lösungsmitteln deutlich erleichtert wird, wenn diese unter niedrigerem Druck durchgeführt wird. Zusätzlich unterstützt wird die Desorption, wenn der Filter während dieses Arbeitsgangs beheizt wird, beispielsweise durch die Abwärme des Verdichters. Besonders geeignet für wechselnde Drücke ist ein Aktivkohlefilter, bei welchem die Aktivkohle als Schüttung in Rohrbündel eingebracht ist. Hier ist die Aktivkohle auch besonders leicht beheizbar.The adsorption filter required especially when using CHC solvents is preferably an activated carbon filter, which also with changing pressures can be applied: The loading of the activated carbon with adsorbed solvents is significantly improved if the adsorption takes place at higher pressure, while the desorption required for the regeneration of the filter of solvents is significantly facilitated if this is lower Pressure is performed. Desorption is also supported when the filter is heated during this operation, for example by the waste heat of Compressor. An activated carbon filter, is particularly suitable for changing pressures which the activated carbon is introduced as a bed in a tube bundle. Here is the Activated carbon is also particularly easy to heat.

Die Anlage sollte mit einem Ventil zur Notentlüftung verbunden sein, um eventuell vorhandene, hohe Drücke in kürzester Zeit abbauen zu können; diese Notentlüftung erfolgt vorzugsweise über den Adsorptionsfilter, um Umweltbelastungen oder Gesundheitsgefahren auch bei einer Notentlüftung zu minimieren.The system should be connected to a valve for emergency ventilation, if necessary to be able to reduce existing, high pressures in the shortest possible time; this emergency vent is preferably done via the adsorption filter to reduce environmental pollution or Minimize health risks even with emergency ventilation.

Der in der erfindungsgemäßen Anlage vorhandene Verdichter ist bevorzugt ein Flüssigkeitsringvakuumverdichter, der bei Bedarf mit einer Drehschieberpumpe kombiniert werden kann. Der Flüssigkeitsringvakuumverdichter zeichnet sich vor allem dadurch aus, daß er direkt mit der Betriebsflüssigkeit betrieben wird und die Kondensation in der Betriebsflüssigkeit stattfindet.The compressor present in the system according to the invention is preferably a Liquid ring vacuum compressor with a rotary vane pump if required can be combined. The liquid ring vacuum compressor outlines all from the fact that it is operated directly with the operating fluid and the Condensation in the operating fluid takes place.

Das verwendete Lösungsmittel oder Lösungsmittelgemisch besteht vorzugsweise im wesentlichen aus Wasser oder wässrigen Reinigern. Es können aber auch Chlorkohlenwasserstoffe, insbesondere Tetrachlorethen und/oder Trichlorethylen als Basis für das Lösungsmittel oder Lösungsmittelgemisch eingesetzt werden. Im Rahmen der Erfindung können auch noch andere Lösungsmittel, z.B. modifizierte Alkohole, verwendet werden. Bei wässrigen Systemen wirkt sich allerdings die erfindungsgemäße Energieeinsparung am deutlichsten aus, da Wasser eine ca. zehnmal höhere Verdampfungsenergie benötigt, als beispielsweise Tetrachlorethen.The solvent or solvent mixture used is preferably essentially from water or aqueous cleaners. But it can also Chlorinated hydrocarbons, especially tetrachlorethylene and / or trichlorethylene can be used as the basis for the solvent or solvent mixture. in the Other solvents, e.g. modified Alcohols. In aqueous systems, however, the one according to the invention has an effect Energy saving is most obvious because water is approx. Evaporation energy required ten times higher than, for example, tetrachlorethylene.

Ein Ausführungsbeispiel der Erfindung wird nun anhand der beigefügten Zeichnung näher beschrieben und erläutert.An embodiment of the invention will now be described with reference to the accompanying drawings described and explained in more detail.

Die einzige Figur zeigt eine schematische Darstellung einer bevorzugten Ausführungsform der erfindungsgemäßen Anlage. Es handelt sich um eine Anlage zur Reinigung von Metallteilen mittels eines chlorkohlenwasserstoffhaltigen Lösungsmittels. Sie besteht in der Hauptsache aus einem Verdichter 11, einem Verdampfer 12, einer Arbeitskammer 13, einem Vorratsbehälter 14, einem Kondensator 15 und einem Adsorptionsfilter 16. Diese Aggregate sind über ein Rohrleitungssystem verbunden, das zwei Filter 17a und 17b, die einem ersten Tank 14a und einem zweiten Tank 14b des Vorratsbehälters 14 zugeordnet sind, einen Meßcomputer 38 sowie eine Anzahl von Ventilen 19 bis 37 enthält. Beim Betrieb einer solchen Anlage mit wässrigen Lösungsmitteln kann der Adsorptionsfilter 16 entfallen.The single figure shows a schematic representation of a preferred embodiment the system according to the invention. It is a system for Cleaning metal parts using a chlorinated hydrocarbon solvent. It mainly consists of a compressor 11, an evaporator 12, a working chamber 13, a reservoir 14, a condenser 15 and an adsorption filter 16. These units are via a piping system connected, the two filters 17a and 17b, the first tank 14a and one are assigned to a second tank 14b of the storage container 14, a measuring computer 38 and contains a number of valves 19 to 37. When operating such a system with aqueous solvents, the adsorption filter 16 can be omitted.

Der Verdampfer 12 und der Kondensator 15 sind mit einem separaten Rohrleitungssystem für einen Wärmeträgerkreislauf verbunden, das eine Stützheizung 45 für den Verdampfer 12, eine Pumpe 46 und einen Kühler 47 für den Kondensator 15 aufweist. Der verwendete Wärmeträger ist bevorzugt Wasser.The evaporator 12 and the condenser 15 are with a separate piping system connected for a heat transfer circuit, the support heater 45th for the evaporator 12, a pump 46 and a cooler 47 for the condenser 15 has. The heat transfer medium used is preferably water.

Der Verdampfer 12 ist für eine kontinuierliche Verdampfung des Lösungsmittels unter Vakuum, bei Drücken von 0,01 bis 0,95 bar vorgesehen. Verunreinigungen des Lösungsmittels, wie Schmierstoffe, reichem sich dabei im Sumpf des Verdampfers 12 an und können bei Bedarf abgelassen oder separat ausdestilliert werden. Die kontinuierliche Verdampfung unter Vakuum kann bei einer wesentlich niedrigeren Temperatur erfolgen als unter Atmosphärendruck, was einerseits für das Lösungsmittel sehr schonend ist und andererseits ermöglicht, den Verdampfer 12 mit der Abwärme des Kondensators 15 zu betreiben. Der Lösungsmitteldampf wird vom Verdichter 11 angesaugt.The evaporator 12 is for continuous evaporation of the solvent provided under vacuum, at pressures from 0.01 to 0.95 bar. impurities the solvent, such as lubricants, accumulate in the bottom of the evaporator 12 on and can be drained or distilled separately if necessary. The continuous evaporation under vacuum can be essential at one lower temperature than under atmospheric pressure, which on the one hand for the solvent is very gentle and on the other hand enables the evaporator 12 to operate with the waste heat of the capacitor 15. The solvent vapor is sucked in by the compressor 11.

Der Verdichter 11 ist eine Kombination aus Drehschieberpumpe und Flüssigkeitsringvakuumverdichter, der für eine kontinuierliche, mehrstufige Komprimierung von Lösungsmitteldämpfen, gegebenenfalls unter Beimischung von Luft, geeignet ist. Er erzeugt beispielsweise eingangsseitig ein Vakuum von bis zu 10 mbar und ausgangsseitig einen Überdruck von ca. 6 bar. Der komprimierte Lösungsmitteldampf wird über ein angesteuertes Dreiwege-Ventil 18 entweder dem Adsorptionsfilter 16, dem Kondensator 15 oder, gesteuert über das Ventil 23, gleich dem Vorratsbehälter 14 zugeführt. The compressor 11 is a combination of a rotary vane pump and a liquid ring vacuum compressor, for continuous, multi-level compression of solvent vapors, if necessary with the addition of air is. For example, it generates a vacuum of up to 10 mbar and an overpressure of approx. 6 bar on the output side. The compressed solvent vapor via a controlled three-way valve 18 either the adsorption filter 16, the condenser 15 or, controlled by the valve 23, equal to the reservoir 14 fed.

Der Kondensator 15 ist als Druckbehälter ausgeführt. Die Kühlung des Kondensators 15 erfolgt über den separaten Wärmeträgerkreislauf mit dem im Verdampfer 12 abgekühlten Wasser; gegebenenfalls wird das Wasser im Kühler 47 zuvor noch weiter heruntergekühlt. Der Lösungsmitteldampf wird im Kondensator 15 bei Drücken von ca. 3 bis 8 bar auskondensiert. Durch den hohen Druck kondensiert das Lösungsmittel bei einer höheren Taupunkttemperatur als unter Atmosphärendruck aus. Hierdurch reicht das vom Verdampfer 12 kommende Wasser zur Kühlung des Kondensats normalerweise aus. Das Kondensat wird in einem Tropfenabscheider 39 gesammelt und von eventuell vorhandenem Wasser, das insbesondere durch Luftfeuchtigkeit anfällt, getrennt. Anschließend wird das kondensierte Lösungsmittel entweder über das angesteuerte Ventil 24 in den Vorratsbehälter 14 oder über das angesteuerte Ventil 22 direkt in die Arbeitskammer 13 geleitet.The condenser 15 is designed as a pressure vessel. Cooling the condenser 15 takes place via the separate heat transfer circuit with that in the evaporator 12 cooled water; if necessary, the water in the cooler 47 is previously further cooled down. The solvent vapor is in the condenser 15 at pressures condensed from about 3 to 8 bar. This condenses due to the high pressure Solvent at a higher dew point temperature than under atmospheric pressure out. As a result, the water coming from the evaporator 12 is sufficient to cool the Condensate normally. The condensate is in a droplet separator 39 collected and from any water that is present, in particular through Humidity occurs separately. Then the condensed solvent either via the controlled valve 24 in the reservoir 14 or passed directly into the working chamber 13 via the controlled valve 22.

Die Arbeitskammer 13 ist als Druckbehälter ausgeführt, beispielsweise mit einer dreh- und schwenkbaren Korbaufnahme, in welcher ein Arbeitskorb aufgenommen wird (in der Zeichnung nicht dargestellt). Die zu reinigenden Metallteile werden von Hand oder mit einer automatischen Beschickungsvorrichtung vorzugsweise in Lochkästen in die Arbeitskammer 13 eingebracht und diese mittels einer Schiebetür 41 verschlossen. Aus Sicherheitsgründen ist die Schiebetür 41 vorzugsweise mit einem Kniehebelverschluß ausgestattet. Über das Ventil 28 kann flüssiges Lösungsmittel aus dem Vorratsbehälter 14, und über das Ventil 27 kann wahlweise frisch kondensiertes, flüssiges Lösungsmittel aus dem Kondensator 15, Lösungsmitteldampf aus dem Verdichter 11 oder gereinigte Luft aus dem Adsorptionsfilter 16 in die Arbeitskammer 13 eingeleitet werden. Das Ventil 29 ermöglicht eine direkte Belüftung der Arbeitskammer 13 mit Umgebungsluft. Über einen Ablauf 42 am Boden der Arbeitskammer 13 kann Lösungsmittel nach dem Reinigungsvorgang aus der Arbeitskammer entnommen und über die Ventile 30 und 31 in den Vorratsbehälter 14 geleitet werden. Das Ventil 26 ermöglicht schließlich eine direkte Anbindung der Arbeitskammer 13 an die Eingangsseite des Verdichters 11.The working chamber 13 is designed as a pressure vessel, for example with a rotatable and swiveling basket holder, in which a work basket is added is (not shown in the drawing). The metal parts to be cleaned are from Hand or with an automatic loading device, preferably in Hole boxes introduced into the working chamber 13 and this by means of a sliding door 41 closed. For safety reasons, the sliding door 41 is preferred equipped with a toggle lock. Liquid solvent can flow through the valve 28 from the reservoir 14, and via the valve 27 can optionally freshly condensed liquid solvent from the condenser 15, solvent vapor from the compressor 11 or purified air from the adsorption filter 16 are introduced into the working chamber 13. The valve 29 enables direct Ventilation of the working chamber 13 with ambient air. Via an outlet 42 at the bottom of the working chamber 13 can solvent after the cleaning process removed from the working chamber and via the valves 30 and 31 into the reservoir 14 are directed. The valve 26 finally enables a direct connection the working chamber 13 to the inlet side of the compressor 11.

Der Vorratsbehälter 14 ist zweiteilig ausgebildet, mit einem ersten Tank 14a und einem zweiten Tank 14b, die durch einen Überlauf 44 voneinander getrennt sind. Die Tanks 14a und 14b werden durch aus der Arbeitskammer 13 entnommenes, im allgemeinen verunreinigtes Lösungsmittel gespeist. Darüber hinaus kann in den zweiten Tank 14b über das Ventil 24 frisches Kondensat aus dem Kondensator 15 und - zur Druckbeaufschlagung - über das Ventil 23 Lösungsmitteldampf direkt aus dem Verdichter 11 eingeleitet werden. Das vom zweiten Tank 14b in den ersten Tank 14a überlaufende Lösungsmittel verdünnt das im ersten Tank 14a befindliche, von einer Tankheizung 43 erwärmte Lösungsmittel. Über die Ventile 34 und 28 bzw. 35 und 28 kann flüssiges Lösungsmittel aus dem Tank 14a bzw. 14b über einen Filter 17a bzw. 17b in die Arbeitskammer 13 gedrückt werden. Über das angesteuerte Ventil 32 kann der Verdampfer 12 flüssiges Lösungsmittel oder - zur Evakuierung des Vorratsbehälters 14 - Lösungsmitteldampf aus dem ersten Tank 14a ansaugen. Weiterhin ist flüssiges Lösungsmittel aus den Tanks 14a und 14b über die Filter 17a und 17b sowie über die Ventile 36 und 37 in den Verdampfer 12 überführbar.The reservoir 14 is formed in two parts, with a first tank 14a and a second tank 14b, which are separated from one another by an overflow 44. The tanks 14a and 14b are removed from the working chamber 13 in the general contaminated solvent. In addition, in the second tank 14b via the valve 24 fresh condensate from the condenser 15 and - for pressurization - via the valve 23 solvent vapor directly the compressor 11 are initiated. That from the second tank 14b to the first Solvent overflowing in tank 14a dilutes the solvents heated by a tank heater 43. Via the valves 34 and 28 or 35 and 28 can over liquid solvent from the tank 14a or 14b a filter 17a or 17b are pressed into the working chamber 13. About the controlled Valve 32 can be the evaporator 12 liquid solvent or Evacuation of reservoir 14 - solvent vapor from the first tank 14a. There is also liquid solvent from the tanks 14a and 14b via the filters 17a and 17b and via the valves 36 and 37 into the evaporator 12 transferable.

Der (nur bei CKW-Anlagen erforderliche) Adsorptionsfilter 16 ist schließlich als Druckbehälter mit einem Aktivkohle-Festbett als Adsorbens ausgebildet. Die Aktivkohle befindet sich dabei als Schüttung in Rohrbündeln 40. Während der Adsorption von Lösungsmitteldämpfen steht der Adsorptionsfilter 16 unter Druck, wodurch sich die Aufnahmekapazität der Aktivkohle erheblich vergrößert. Der Adsorptionsfilter 16 ist über die beiden Dreiwege-Ventile 18 und 21 direkt mit dem Verdichter 11 verbindbar, so daß er wahlweise mit Überdruck oder mit Vakuum beaufschlagt werden kann: Die Regeneration der Aktivkohle erfolgt unter Vakuum, gegebenenfalls unter zusätzlicher Heizung der Aktivkohle mit der Abwärme des Verdichters 11 über ein Heizrohr 48, wodurch die Desorption des Lösungsmittels erheblich beschleunigt wird. Bei der Desorption kann der Adsorptionsfilter 16 durch Umsteuern des Dreiwege-Ventils 21 mit dem Kondensator 15 verbunden werden. Über die Ventile 27 und 20 ist der Adsorptionsfilter 16 mit der Arbeitskammer 13 verbindbar, so daß dort durch den Adsorptionsfilter 16 geleitete, von Lösungsmitteldämpfen gereinigte Luft eingeleitet werden kann.The adsorption filter 16 (only required in CHC systems) is finally as Pressure vessel with an activated carbon fixed bed designed as an adsorbent. The activated carbon is located as a bed in tube bundles 40. During adsorption of solvent vapors, the adsorption filter 16 is under pressure, whereby the absorption capacity of the activated carbon increases considerably. The adsorption filter 16 is via the two three-way valves 18 and 21 directly to the compressor 11 connectable, so that it is either pressurized or vacuum can be: The regeneration of the activated carbon takes place under vacuum, if necessary with additional heating of the activated carbon with the waste heat from the compressor 11 via a heating tube 48, which considerably accelerates the desorption of the solvent becomes. During desorption, the adsorption filter 16 can be reversed of the three-way valve 21 are connected to the condenser 15. About the Valves 27 and 20, the adsorption filter 16 can be connected to the working chamber 13, so that there passed through the adsorption filter 16 of solvent vapors cleaned air can be introduced.

Bei einem kritischen Zustand der Anlage (zu hoher Druck oder zu hohe Lösungsmittelkonzentration) kann Luft über ein Notentlüftungsventil 19 abgeführt werden. Normalerweise entweicht die Luft über ein Überströmventil bei Drücken von ca. 3 bis 8 bar. If the system is in a critical condition (too high pressure or too high solvent concentration) can be discharged via an emergency vent valve 19. The air normally escapes through an overflow valve at pressures of approx. 3 up to 8 bar.

Die eben beschriebene Anlage wird als Beispiel für das erfindungsgemäße Verfahren folgendermaßen betrieben:The system just described is an example of the method according to the invention operated as follows:

(a) Anfahrvorgang(a) Starting process

In den Vorratsbehälter 14 wird flüssiges Lösungsmittel gefüllt, das über die Ventile 36 und 37 auch in den Verdampfer 12 gelangt. Der Verdichter 11 wird gestartet und das Ventil 33 geöffnet, so daß der Verdampfer 12 evakuiert wird. Die Pumpe 46, die zur Umwälzung des Wärmeträgers Wasser dient, und die Stützheizung 45 werden in Betrieb genommen. Das von der Stützheizung 45 erwärmte Wasser wird durch den Verdampfer 12 geleitet, wodurch das darin befindliche flüssige Lösungsmittel verdampft und vom Verdichter 11 angesaugt wird. Der Verdichter 11 komprimiert den angesaugten Lösungsmitteldampf auf einen Druck von ca. 3 bis 8 bar. Bei Bedarf kann über die Ventile 26 und 29 zusätzlich Luft zugeführt werden.Liquid solvent is filled into the storage container 14 via the valves 36 and 37 also reaches the evaporator 12. The compressor 11 is started and the valve 33 opened so that the evaporator 12 is evacuated. The pump 46, which serves to circulate the heat transfer medium water, and the auxiliary heater 45 are put into operation. The water heated by the auxiliary heater 45 becomes passed through the evaporator 12, causing the liquid solvent therein evaporates and is sucked in by the compressor 11. The compressor 11 compresses the suctioned solvent vapor to a pressure of approx. 3 to 8 bar. If necessary, additional air can be supplied via the valves 26 and 29.

(b) Reinigen mit flüssigem Lösungsmittel(b) Clean with liquid solvent

Der vom Verdichter 11 komprimierte Lösungsmitteldampf wird durch Öffnen der Ventile 18 und 23 in den Vorratsbehälter 14 geleitet. Hierdurch wird im Vorratsbehälter 14 ein Überdruck, beispielsweise mit ca. 5 bar, erzeugt. Das Ventil 32 bleibt dabei geschlossen.The solvent vapor compressed by the compressor 11 is opened by opening the Valves 18 and 23 passed into the reservoir 14. This will result in the reservoir 14 generates an overpressure, for example with approximately 5 bar. The valve 32 remains closed.

Durch Öffnen der Ventile 34 und 28 wird flüssiges Lösungsmittel aus dem Tank 14a in die Arbeitskammer 13 gedrückt, da diese nach dem Beschicken mit Metallteilen und dem Schließen der Schiebetür 41 noch unter Atmosphärendruck steht. Hierbei werden grobe Verunreinigungen des Lösungsmittels im Filter 17a zurückgehalten. Um die Arbeitskammer 13 mit Lösungsmittel fluten zu können, kann sie über das Ventil 26 zum Verdichter 11 hin entlüftet werden.By opening valves 34 and 28, liquid solvent is removed from the tank 14a pressed into the working chamber 13, since these are loaded with metal parts and the closing of the sliding door 41 is still under atmospheric pressure. In this way, rough impurities of the solvent are retained in the filter 17a. In order to flood the working chamber 13 with solvent, it can are vented to the compressor 11 via the valve 26.

Die in einem Arbeitskorb in der Arbeitskammer 13 angeordneten Metallteile werden durch Einsprühen von flüssigem Lösungsmittel einer Primärreinigung unterzogen. Durch allmähliches Fluten der Arbeitskammer 13 mit Lösungsmittel bis zu einem von einem (nicht dargestellten) Füllstandsregler kontrollierten Füllstand werden die Metallteile im Tauchbad gereinigt. Dies geschieht vorzugsweise unter Rotationsund Schwenkbewegungen des Arbeitskorbs im Lösungsmittelbad.The metal parts arranged in a work basket in the work chamber 13 are undergo primary cleaning by spraying liquid solvent. By gradually flooding the working chamber 13 with solvent to one the level is controlled by a level controller (not shown) Metal parts cleaned in the immersion bath. This is preferably done under rotation and Swiveling movements of the basket in the solvent bath.

Zur Beendigung des Reinigungsvorgangs wird der im Vorratsbehälter 14 vorhandene Überdruck über das Ventil 32 abgebaut und gegebenenfalls ein Vakuum erzeugt. Danach wird das Ventil 30 geöffnet und die Arbeitskammer 13 über die Ventile 19, 20 und 27 belüftet, so daß das Lösungsmittel in den Tank 14a abfließt.To end the cleaning process, the one present in the storage container 14 becomes Overpressure is released via valve 32 and, if necessary, a vacuum is generated. Then the valve 30 is opened and the working chamber 13 via the Valves 19, 20 and 27 are vented so that the solvent flows into the tank 14a.

Alternativ kann auch aus dem zweiten Tank 14b, durch Öffnen der Ventile 35 und 28, gereinigt sowie die Arbeitskammer 13 durch Öffnen des Ventils 31 in den Tank 14b entleert werden.Alternatively, from the second tank 14b, by opening the valves 35 and 28, cleaned and the working chamber 13 by opening the valve 31 in the tank 14b can be emptied.

(c) Kontinuierliches Aufbereiten des Lösungsmittels(c) Continuous preparation of the solvent

Der Verdichter 11 sorgt gleichzeitig mit der Erzeugung der für die Transportvorgänge verwendeten Druckdifferenzen für eine Aufbereitung des Lösungsmittels, indem er den aus dem Verdampfer 12 abgesogenen Lösungsmitteldampf komprimiert über das Ventil 18 in den Kondensator 15 leitet. Der Kondensator 15 wird von dem im Verdampfer 12 abgekühlten Wasser, dessen Temperatur nötigenfalls durch den zusätzlichen Kühler 47 weiter abgesenkt wird, gekühlt; die Abwärme des Kondensators 15 sorgt im Gegenzug für die Heizung des Verdampfers 12. Wenn der vom Verdichter 11 erzeugte Überdruck im Vorratsbehälter 14 nicht mehr benötigt wird, kann durch Schließen des Ventils 23 und Öffnen des Ventils 24 frisch kondensiertes Lösungsmittel aus dem Kondensator 15 in den Vorratsbehälter 14 mittels Druckdifferenz eingeleitet werden. Das Lösungsmittel wird also kontinuierlich destilliert.The compressor 11 takes care of the generation of the transport operations pressure differences used for processing the solvent, by compressing the solvent vapor drawn from the evaporator 12 conducts into the condenser 15 via the valve 18. The capacitor 15 will of the water cooled in the evaporator 12, its temperature if necessary is further lowered by the additional cooler 47, cooled; the waste heat of the In turn, capacitor 15 provides for heating the evaporator 12. If the excess pressure generated by the compressor 11 in the reservoir 14 is no longer required can be fresh by closing the valve 23 and opening the valve 24 condensed solvent from the condenser 15 into the storage container 14 be initiated by means of a pressure difference. So the solvent becomes continuous distilled.

(d) Spülen mit Hochdruckkonddensat(d) Rinse with high pressure condensate

Anstatt das Lösungsmittel vom Kondensator 15 in den Vorratsbehälter 14 zu leiten, kann das frisch kondensierte Lösungsmittel durch Schließen der Ventile 23 und 24 und Öffnen des Ventils 22 direkt und vorzugsweise unter hohem Druck (herrührend vom Verdichter 11) in die Arbeitskammer 13 geleitet und dort beispielsweise eingesprüht werden. Die erforderliche Entlüftung der Arbeitskammer 13 erfolgt über das Ventil 26.Instead of passing the solvent from the condenser 15 into the reservoir 14, the freshly condensed solvent can be closed by closing valves 23 and 24 and opening the valve 22 directly and preferably under high pressure (originating from the compressor 11) passed into the working chamber 13 and sprayed there, for example become. The required venting of the working chamber 13 takes place via the valve 26.

Das Kondensat weist eine hohe Reinheit auf, wodurch es sich in erster Linie für die Nachreinigung der Metallteile eignet.The condensate is of high purity, which makes it primarily suitable for the post-cleaning of the metal parts is suitable.

(e) Spülen mit Hochdruckdampf(e) Rinsing with high pressure steam

Über die Ventile 18, 23, 30 und 31 kann Lösungsmitteldampf direkt aus dem Verdichter 11 in die Arbeitskammer geleitet werden, vorzugsweise unter hohem Druck. Auch hier erfolgt eine gegebenenfalls notwendige Entlüftung der Arbeitskammer 13 über das Ventil 26. Dieses Hochdruckdampfspülen eignet sich für eine abschließende Feinstreinigung der Metallteile und/oder zum Erhitzen derselben, um eine anschließende Trocknung zu beschleunigen.Solvent vapor can be drawn directly from the compressor via the valves 18, 23, 30 and 31 11 are passed into the working chamber, preferably under high pressure. Here, too, any necessary ventilation of the working chamber 13 takes place via valve 26. This high pressure steam rinsing is suitable for a final Fine cleaning of the metal parts and / or for heating them to a accelerate subsequent drying.

(f) Vakuumtrocknen(f) vacuum drying

Nach Beendigung des Reinigungsvorgangs werden die Metallteile vor deren Entnahme aus der Arbeitskammer 13 von Lösungsmittelresten getrocknet: Durch Öffnen des Ventils 26 evakuiert der Verdichter 11 Lösungsmitteldampf und Luft, die durch das Beschicken in die Arbeitskammer 13 gelangt ist. Nach Erreichen eines Mindestdrucks wird zur Beendigung des Trocknungsvorgangs das Ventil 27 geöffnet, so daß Außenluft bis zum Erreichen des Atmosphärendrucks in die Arbeitskammer 13 strömt.After the cleaning process is complete, the metal parts are removed before they are removed Dried from solvent residues from working chamber 13: by opening of the valve 26, the compressor 11 evacuates solvent vapor and air has entered the working chamber 13 by the loading. After reaching one Minimum pressure, valve 27 is opened at the end of the drying process, so that outside air is brought into the working chamber until atmospheric pressure is reached 13 streams.

(g) Spülen der Arbeitskammer(g) Flushing the work chamber

Um die Lösungsmittelkonzentration des Lösungsmitteldampf-Luft-Gemischs in der Arbeitskammer 13 vor dem Öffnen unter einen beispielsweise in Deutschland gesetzlich vorgeschriebenen Grenzwert von 1 g/m3 zu bringen, wird die Arbeitskammer 13 durch Öffnen der Ventile 19, 20, 26 und 27 mit Umgebungsluft gespült. Die Lösungsmittelkonzentration wird während der Luftspülung dadurch überwacht, daß das vom Verdichter 11 aus der Arbeitskammer 13 abgesogene Lösungsmitteldampf-Luft-Gemisch über das Ventil 25 durch den Meßcomputer 38 geleitet wird. In order to bring the solvent concentration of the solvent vapor / air mixture in the working chamber 13 before opening to below a legal limit of 1 g / m 3, for example in Germany, the working chamber 13 is opened by opening the valves 19, 20, 26 and 27 with ambient air rinsed. The solvent concentration is monitored during the air purge in that the solvent vapor / air mixture drawn off by the compressor 11 from the working chamber 13 is passed through the measuring computer 38 via the valve 25.

Der Meßcomputer 38 gibt die Schiebetür 41 der Arbeitskammer 13 erst frei, wenn der vorgeschriebene Grenzwert der Lösungsmittelkonzentration unterschritten wird.The measuring computer 38 only releases the sliding door 41 of the working chamber 13 when the prescribed limit of the solvent concentration was undershot becomes.

(h) Reinigen der Luft im Adsorptionsfilter(h) Clean the air in the adsorption filter

Die beim Spülen der Arbeitskammer 13 vom Verdichter 11 abgesogene, Lösungsmitteldämpfe enthaltende Luft wird durch Umsteuern des Ventils 18 unter hohem Druck in den Adsorptionsfilter 16 geleitet, wo die Luft von den Lösungsmitteldämpfen befreit wird. Durch Schließen des Ventils 19 wird die gereinigte Luft zu einer gegebenenfalls notwendigen, fortgesetzten Spülung der Arbeitskammer 13 über die Ventile 20 und 27 im Kreislauf zurückgeführt, bis der vorgeschriebene Grenzwert der Lösungsmittelkonzentration unterschritten ist.The solvent vapors drawn off from the compressor 11 when the working chamber 13 is flushed air contained is by reversing the valve 18 at high Pressure is passed into the adsorption filter 16 where the air vapors from the solvent is released. By closing the valve 19, the cleaned air is closed a possibly necessary, continued flushing of the working chamber 13 returned via the valves 20 and 27 in the circuit until the prescribed The solvent concentration has fallen below the limit.

(i) Regeneration des Adsorptionsfilters(i) Regeneration of the adsorption filter

Zur Desorption des von der Aktivkohle des Adsorptionsfilters 16 aufgenommenen Lösungsmittels wird durch Schließen des Ventils 18 und Umsteuern des Ventils 21 der Behälter des Adsorptionsfilters 16 evakuiert. Der Desorptionsvorgang wird dadurch unterstützt, daß die Rohrbündel 40, welche die Aktivkohle enthalten, über das Heizrohr 48 mit der Abwärme des Verdichters 11 von außen beheizt werden.For the desorption of that absorbed by the activated carbon of the adsorption filter 16 Solvent is released by closing valve 18 and reversing valve 21 the container of the adsorption filter 16 is evacuated. The desorption process is thereby supports that the tube bundle 40, which contain the activated carbon, over the heating tube 48 are heated from the outside with the waste heat of the compressor 11.

Die Verfahrensschritte (g), (h) und (i) sind im vorliegenden Beispiel einer mit CKW-Lösungsmitteln betriebenen Anlage sinnvoll; bei Betrieb einer Anlage mit wässrigen Lösungsmitteln sind diese Verfahrensschritte ohne weiteres verzichtbar. Process steps (g), (h) and (i) are in the present example one with CHC solvents operated system makes sense; when operating a system with aqueous These process steps are easily dispensable for solvents.

BezugszeichenlisteLIST OF REFERENCE NUMBERS

1111
Verdichtercompressor
1212
VerdampferEvaporator
1313
Arbeitskammerworking chamber
1414
Vorratsbehälterreservoir
14a14a
Tank (erster)Tank (first)
14b14b
Tank (zweiter)Tank (second)
1515
Kondensatorcapacitor
1616
Adsorptionsfilteradsorption
17a17a
Filterfilter
17b17b
Filterfilter
1818
DreiwegeventilThree-way valve
19..3719..37
Ventilevalves
3838
Meßcomputermeasuring computer
3939
TropfenabscheiderDroplet
4040
Rohrbündeltube bundle
4141
Schiebetürsliding door
4242
Ablauf (von 13)Expiry (of 13)
4343
Tankheizungtank heater
4444
Überlaufoverflow
4545
StützheizungHeating support
4646
Pumpepump
4747
Kühlercooler
4848
Heizrohrheating pipe

Claims (28)

  1. Process for the surface treatment of components with a solvent or a solvent mixture in a working chamber, especially for cleaning metal components,
    wherein the solvent or solvent mixture is held in closed circuits, which optionally pass through the working chamber, and can be prepared within those circuits by means of vaporisation and subsequent condensation, the vaporisation being carried out at a first, low pressure and the condensation being carried out at a second, higher pressure,
    characterised in that
    the heat generated during the condensation is used at least partly for the vaporisation of the solvent or solvent mixture.
  2. Process according to claim 1, characterised in that the first, low pressure is kept below atmospheric pressure.
  3. Process according to either one of claims 1 and 2, characterised in that the second, higher pressure is kept above atmospheric pressure.
  4. Process according to claim 2, characterised in that the first, low pressure is kept in a range from 0.001 bar to 0.95 bar.
  5. Process according to claim 3, characterised in that the second, higher pressure is kept in a range from 2 bar to 15 bar, preferably from 3 bar to 8 bar.
  6. Process according to any one of claims 1 to 5, characterised in that a condenser used for the condensation of the solvent or solvent mixture is cooled at least partly by a heat transfer medium that is cooled during the vaporisation of the solvent or solvent mixture.
  7. Process according to any one of claims 1 to 6, characterised in that the generation of the first and the second pressure is carried out by a compressor arranged between a vaporiser and a condenser, or the condensation is effected in a compressor.
  8. Process according to any one of claims 1 to 7, characterised in that the solvent or solvent mixture is transported by means of the pressure differences prevailing in the circuit.
  9. Process according to any one of claims 1 to 8, characterised in that the solvent or solvent mixture is held in a fluid state of aggregation in at least one reservoir integrated into one of the circuits.
  10. Process according to any one of claims 1 to 9, characterised in that the surface treatment of the components in the working chamber is carried out optionally with freshly condensed solvent or solvent mixture.
  11. Process according to any one of claims 1 to 10, characterised in that the components in the working chamber are dried after their surface treatment at the first, low pressure.
  12. Process according to any one of claims 1 to 11, characterised in that when the surface treatment is complete, ambient air is admitted to the working chamber and, after the aeration, the air is extracted from the working chamber, the extracted air being freed of solvent or solvent mixture vapours by means of an adsorption filter and being returnable to the working chamber for fresh aeration, and the adsorption filter being acted upon by the second, higher pressure for adsorption of the solvent or solvent mixture and being acted upon by the first, low pressure for desorption of the solvent or solvent mixture.
  13. Process according to any one of claims 1 to 12, characterised in that water or a water-based mixture is used as solvent.
  14. Apparatus for the surface treatment of components with a solvent or a solvent mixture, especially for carrying out the process according to any one of claims 1 to 13,
    having a working chamber (13) for the surface treatment, a vaporiser (12) for vaporising the solvent or solvent mixture and a condenser (15) for condensing the vaporised solvent or solvent mixture,
    the solvent or solvent mixture being held in closed circuits, one of which contains the vaporiser (12) and the condenser (15) as well as a compressor (11) arranged between those components, the compressor (11) generating an input-side first low pressure, which acts upon the vaporiser (12), and an output-side second higher pressure, which acts upon the condenser (15), while the working chamber (13) can be coupled into the circuits as required,
    characterised in that
    between the vaporiser (12) and the condenser (15) there is provided a heat transfer medium circuit for cooling the condenser (15) and for heating the vaporiser (12).
  15. Apparatus according to claim 14, characterised in that the first, low pressure is below atmospheric pressure.
  16. Apparatus according to either one of claims 14 and 15, characterised in that the second, higher pressure is above atmospheric pressure.
  17. Apparatus according to claim 15, characterised in that the first, low pressure is in a range from 0.001 bar to 0.95 bar.
  18. Apparatus according to claim 16, characterised in that the second, higher pressure is in a range from 2 bar to 15 bar, preferably from 3 bar to 8 bar.
  19. Apparatus according to any one of claims 14 to 18, characterised in that the solvent or solvent mixture is transportable by means of the pressure differences generated by the compressor (11).
  20. Apparatus according to any one of claims 14 to 19, characterised in that there is at least one reservoir (14) for the solvent or solvent mixture.
  21. Apparatus according to claim 20, characterised in that for the introduction of solvent or solvent mixture into the working chamber (13) and/or for the discharging of solvent or solvent mixture from the working chamber (13), the reservoir (14) can be connected thereto.
  22. Apparatus according to any one of claims 14 to 21, characterised in that for the introduction of freshly condensed solvent or solvent mixture into the working chamber (13), the condenser (15) can be connected thereto.
  23. Apparatus according to any one of claims 14 to 22, characterised in that there is a valve (20) for admitting air into the working chamber (13).
  24. Apparatus according to claim 23, characterised in that for flushing the working chamber (13), the compressor (11) can be connected thereto and there is an adsorption filter (16) for cleansing air that has been extracted from the working chamber (13) of solvent or solvent mixture vapours.
  25. Apparatus according to claim 24, characterised in that the adsorption filter (16) can be acted upon by the second, higher pressure for adsorption of solvent or solvent mixture and can be acted upon by the first, low pressure for desorption of the solvent or solvent mixture.
  26. Apparatus according to either one of claims 24 and 25, characterised in that the adsorption filter (16) is an active carbon filter in which the active carbon is installed in loosely packed form in tube arrays (40).
  27. Apparatus according to any one of claims 14 to 26, characterised in that the compressor (11) is a liquid-ring vacuum compressor, or consists of a combination of a liquid-ring vacuum compressor with a rotary vane pump.
  28. Apparatus according to any one of claims 14 to 27, characterised in that the solvent or solvent mixture consists substantially of water or of aqueous cleansers.
EP00106230A 1999-03-24 2000-03-22 Process and apparatus for surface treatment of parts with a solvent Expired - Lifetime EP1038992B1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE19913244 1999-03-24
DE19913244 1999-03-24
DE19939032 1999-08-18
DE19939032A DE19939032A1 (en) 1999-03-24 1999-08-18 Process and plant for surface treatment of parts with a solvent

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EP1038992A1 EP1038992A1 (en) 2000-09-27
EP1038992B1 true EP1038992B1 (en) 2003-06-04

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Publication number Priority date Publication date Assignee Title
DE202012103894U1 (en) * 2012-10-11 2014-01-15 Dürr Systems GmbH A surface treatment device
DE102018121915B3 (en) * 2018-09-07 2020-02-13 Dyemansion Gmbh Process for the surface treatment of molded parts

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5232476A (en) * 1990-09-12 1993-08-03 Baxter International Inc. Solvent recovery and reclamation system
US5304253A (en) * 1990-09-12 1994-04-19 Baxter International Inc. Method for cleaning with a volatile solvent
US5415193A (en) * 1992-11-13 1995-05-16 Taricco; Todd Pressure controlled cleaning system
DE4329178B4 (en) * 1993-08-30 2006-11-09 EMO Oberflächentechnik GmbH Vapor cleaning
IL126862A0 (en) * 1998-01-14 1999-09-22 H M E Separation Technologies A system for collecting smoke or odors from open spaces

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ATE242344T1 (en) 2003-06-15
EP1038992A1 (en) 2000-09-27

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