WO2017207486A1

WO2017207486A1 - Method and device for cleaning industrially produced components

Info

Publication number: WO2017207486A1
Application number: PCT/EP2017/062888
Authority: WO
Inventors: Volker Hösel; Peter Hösel
Original assignee: Hösel GmbH; EMO Oberflächentechnik GmbH
Priority date: 2016-05-30
Filing date: 2017-05-29
Publication date: 2017-12-07
Also published as: EP3463699B1; EP3463699A1; DE102016109861A1

Abstract

The invention relates to a method and to a device for cleaning industrially produced metal and/or plastic components using a cleaning agent, characterised in that a mixture of at least two organic solvents and water is used as the cleaning agent, said mixture comprising at least one non-water soluble organic solvent and at least one water-soluble organic solvent. The invention also relates to a device (1) which is suitable for carrying out the method, comprising a working chamber (2) for the components to be cleaned and at least one tank (3, 4) for feeding the working chamber (2) with a solvent mixture by means of at least one supply means (5, 11) for cleaning the components.

Description

Method and device for the cleaning of industrially manufactured parts

description

The invention relates to a method for cleaning industrially manufactured parts made of metal and / or plastic.

For putting in, the invention relates to a device for cleaning of industrially manufactured parts made of metal and / or plastic, in particular to r Du rchführu ng of the method according to the invention.

E in previously known method of the type mentioned is in DE 43 29 1 78 B4 rub rubbing. The parts or objects to be cleaned are introduced into an evacuated cleaning chamber and flooded with a liquid organic solvent at a pressure of 200 mbar or below. Subsequently, the liquid solvent is withdrawn from the cleaning chamber and thereafter the solvent vapor is fed into the cleaning chamber at a pressure of 200 mbar or below at a temperature at or above the flash point of the solvent. This completes the cleaning of the objects by condensation of the solvent vapor on the objects.

There are also known in so-called hybrid cleaning systems or processes in which the parts to be cleaned are treated with an organic solvent and water in a chamber. In this case, for example, water, and subsequently, in a further method step, an organic solvent and subsequently water may again be introduced into the cleaning chamber or working chamber. Alternatively, it is also possible to use first the organic solvent, then water and then again the organic solvent. Between each of these steps, according to the prior art, a particularly time-consuming drying takes place.

Furthermore, in the case of the previously known systems or methods, all steps are carried out one after the other, which may take approximately 20 minutes in each case, so that a relatively long cleaning process results overall. If the solvent is first applied, it may be disadvantageously found that inorganic substances remaining on the parts to be cleaned are liable to adhere strongly during drying because of the relatively high temperature and are difficult to remove. If, on the other hand, water is added to the next one, it fouls relatively strongly, which leads to a shortened service life and again increased expenditure.

When an evaporator is used in the prior art to purify the process water, it requires a considerable amount of energy, or a relatively large amount of waste water to be disposed of.

In view of these disadvantages, the invention has the object of specifying a method and a device of the type mentioned above with which an improved cleaning experience can be achieved in a shorter time and with less effort.

This object is achieved according to the invention du rch a method with the features of claim 1 and you rch a device having the features of claim 21. Advantageous developments of the idea according to the invention are each the subject of dependent claims.

An inventive method for cleaning of industrially manufactured parts from metal and / or plastic using a cleaning agent is characterized in that a mixture of at least two organic solvents and water is used as the cleaning agent, which mixture does not interfere with at least one water-soluble organic solvent and at least one water-soluble organic solvent. With such a detergent, both non-water-soluble (fat-soluble) and water-soluble impurities can be removed from the components to be cleaned in one go.

Advantageously, the method includes the following steps: a) introducing parts to be cleaned into a working chamber; b) loading the working chamber with water and with a solvent mixture containing at least one first water-insoluble organic solvent and at least one second water-soluble organic solvent;

c) Clean the parts in the working chamber by means of the water-solvent mixture.

A device according to the invention for cleaning industrially manufactured parts made of metal and / or plastic, in particular for the purpose of carrying out the method according to the invention, comprising: a) a working chamber for receiving parts to be cleaned;

b) Tan kmittel to m providing water and a solvent mixture containing at least a first water-insoluble, organic solvent and at least one second wasserlösl iches, organic solvent, which tank means to m the loading of the working chamber with the water and the solvent mixture with the working chamber in Flu idverbindung stand;

c) conveying to m conveying the water and the solvent mixture in the working chamber in order to clean the parts in the working chamber by means of the water-solvent mixture.

Surprisingly, it has been found by extensive experiments by the Applicant that in the course of the process according to the invention demixing (a demulsification) of the water / solvent mixture (hereinafter also referred to as cleaning agent) occurs, with the second, water-soluble organic solvent becoming free of oil when water comes along. In this way, grease or oil-containing (organic) contaminants on the one hand and inorganic contaminants on the other hand can be eliminated in principle in one operation, which results in corresponding time and cost advantages. Also in energetic terms, the process according to the invention is advantageous, since the repeated drying known from the prior art, which is correspondingly energy-consuming, is unnecessary.

As a cleaning agent according to the invention a mixture of at least two organic solvents and water is used. A further development of the According to the inventive method provides that the water-solvent mixture or the cleaning agent in addition still contains a clean ing amplifier, such as a surfactant and / or an amine. In this way, the cleaning effect can be strengthened in a conventional manner.

E ine another development of the method according to the invention provides that in Sch ritt c) a rolling of the parts and / or the water-solvent mixture in the working chamber takes place in order to improve the cleaning effect and to this end a dispersion (with liquid components specifically an emulsion) of the components of the water-solvent mixture.

In the course of another development of the method according to the invention, it is provided that the parts are removed from the working chamber or the water-solvent mixture (the cleaning agent) is discharged from the working chamber at the end of step c). In particular, the water-solvent mixture can be fed to an evaporator to recover all the constituents of the cleaning agent (first solvent, second solvent and water). Alternatively, however, a plurality of evaporators can be used in order to reduce recovery.

E ine a corresponding development of the device according to the invention is characterized by you rch evaporator means and capacitor means in Flu idverbindung with the Tan kmittel and the working chamber.

Yet another further development of the method provides that the parts to be cleaned are optionally pre-cleaned with an organic solvent, in particular the first solvent, the second solvent or another solvent, before or after the step a) in the working chamber be introduced or were.

Furthermore, it can be provided that in step b) the water-solvent mixture or the cleaning agent is introduced in liquid form into the working chamber wi rd. The temperature is preferably below the flash point to at least one of the two solvents. A particularly preferred embodiment of the method according to the invention provides that, at least during steps b) and c), a pressure and a temperature are generated and maintained in the working chamber so that no explosive mixture of air and solvent vapor is produced.

Furthermore, it is generally not necessary to introduce the water and the solvents in already mixed form in the working chamber, but also comes a separate loading of the working chamber with the water and / or solvents into consideration.

A particularly preferred embodiment of the method according to the invention provides that subsequently, i. after step c), the working chamber is evacuated and at least one organic solvent in liquid, vapor or mixed liquid-vapor state at a negative pressure to the environment, preferably at a pressure of 400 mbar or 200 mbar or lower and with a temperature at or above the Flash point of the solvent in question is fed into the evacuated working chamber and the cleaning is completed by condensation of the solvent vapor on the parts. This essentially corresponds to step b) of claim 1 from DE 4329178 B4, which has proved to be particularly effective and advantageous in order to achieve a good cleaning result. The above-mentioned solvent may be the first, the second or another suitable solvent.

Additionally or alternatively, it may be provided that, following step c) hot water at a temperature of preferably above 50 ° C is introduced into the working chamber, wherein preferably in both cases, first the water-solvent mixture was discharged from the working chamber.

To complete the cleaning process, the cleaned parts can then be dried. This drying can be done in the working chamber itself, but without the invention being limited thereto.

As already mentioned, it can be provided in the development of the method according to the invention that, after cleaning, the water Solvent mixture or the cleaning agent is purified by evaporation and / or filtration and prepared for reuse.

A corresponding development of the device according to the invention is characterized by you rch filter means for the water and for the first and second solvents in fluid communication with the Tan kmittel and the working chamber.

Although treatment by means of an evaporator or several evaporators may be preferred, purification or treatment, in particular, is also a matter of ion exchanger or (reverse osmosis) osmosis in the context of the invention. Basically Techni ken can be applied, as they also come to r desalting of water to m use and the skilled person are known per se.

An advantage in the use of evaporators with respect to ion exchangers or the like may consist in the fact that any purifying booster additives can be recovered as a result.

The detergent preferably contains, based on the proportion of the water-soluble organic solvent, a water content of at least about 10 vol%, preferably at least about 30 vol%, most preferably at least about 50 vol%.

More preferably, the cleaning agent contains, based on the total amount of water-soluble organ ischemic solvent and water, 10 to 90 vol .-% n water-soluble organic solvent.

Particularly suitable is a mixing ratio between non-water-soluble solvent and the total amount of the water-soluble solvent and water of about 10:90, preferably 30:70, most preferably 50:50.

In particular, the quantitative ratio of the first solvent, second solvent and water can be about 1: 1: 1, whereby in principle I can say that the mixture remains functional longer in the context of the invention, the more water it contains. The mixing ratios can be - as mentioned - set when filling the working chamber. This is done by pumping the individual constituents of the cleaning agent, such as the organic solvents, water and optionally other substances, from separate (storage) containers or tank means, in the respectively required amount, and thereby combining them into the desired detergent mixture.

In the course of yet another development of the method according to the invention, it can be provided that the first solvent and / or the second solvent are each a solvent mixture, the constituents of the respective mixture then each having the basic properties of the first solvent (water-insoluble). or of the second solvent (water-soluble). Furthermore, certain additives, such as surfactants, amines or the like may be added to the water used.

Since the first solvent and the second solvent separate after performing part cleaning due to their respective properties, wherein the first solvent organic pollutants (oils, fats) and the second solvent has absorbed inorganic contaminants, in principle, a physical-mechanical separation of the mixture can be performed For example, by means of an overflow or a targeted lowering down. Such a separation can be used in addition to the already mentioned evaporation and / or filtration.

A corresponding development of the device according to the invention is characterized by separation means for oil and / or water in fluid communication with the evaporator and condenser means.

Especially for the first, water-insoluble solvent, the quantitative ratio or an absolute amount can be chosen so that a sufficient phase thickness (after separation) results to correspond to a known or assumed degree of contamination of the parts to be cleaned, ie completely absorb the pollution in question , Yet another development of the method according to the invention may involve generating and maintaining a negative pressure relative to the environment at least during steps e) and c) in the working chamber. If the ambient pressure is about 1 bar, it can be provided, without limitation, that a negative pressure with an absolute value of about 100 mbar or about 200 mbar to 400 mbar is generated in the working chamber. This is used in particular for explosion protection.

A corresponding development of the device according to the invention is characterized by pressure generating means in fluid communication with the evaporator and condenser means and / or with the working chamber.

Alternatively, however, it can also be provided that, at least during steps b) and c), an overpressure relative to the environment is generated and maintained in the working chamber. The overpressure can be, for example, up to 1 bar above the ambient pressure.

As already mentioned, the cleaning agent preferably comprises at least one water-soluble organic solvent, the water-soluble organic solvent containing more than 5% by volume (20% by volume, 30% by volume, 50% by volume). ) dissolves in water, and at least one non-water-soluble organic solvent, wherein the non-water-soluble organic solvent in a proportion of less than 5 vol .-%, preferably <1% by volume, more preferably <0, 1 vol. -%, dissolved in water. With such a detergent, both non-water-soluble (fat-soluble) and water-soluble impurities can be removed from the components to be cleaned.

As solvents for the cleaning agent, organic solvents are used, such as:

Hydrocarbons (RH) such as n-hexane, petrol, benzene, benzene homologues such as styrene, suitably aliphatic hydrocarbons containing from 5 to 18 carbon atoms, such as cyclic saturated hydrocarbons and straight or branched chain saturated or unsaturated hydrocarbons, preferably cycloalkanes, n Paraffins, iso- paraffins or (test) gasolines (such as Stoddard solvent), or aromatic hydrocarbons, such as toluene or xylene;

Alcohols (-OH), such as methanol, ethanol, isobutanol, propanol, isopropanol, phenol, hexanol, alkoxypropanols or alkoxyethanols;

Ketones (R-CO), such as acetone, methyl ketone (MEK), methyl isobutyl ketone (MIBK);

Esters, such as alkyl lactates, dibasic esters, commercially available mixtures of dibasic esters;

Ethers, such as dipropylene glycol monomethyl ether (DPM), diethyl ether or hydroxy ether;

- carboxylic acids (R-COOH), such as formic acid, acetic acid;

- glycols (HO-R-OH), such as ethanediol (ethylene glycol, glycol), propanediol (propylene glycol), diethylene glycol, triethylene glycol;

Amino compounds (R-NCOH), such as aniline, β-naphthylamine, benzidine;

Amides, such as dimethylformamide (DMF),

Hydrocarbon sulfur compounds such as dimethyl sulfoxide (DMSO), carbon disulfide, and

cyclic siloxanes containing, suitably, 6 to 8 ring atoms, or a mixture of two or more such compounds.

Suitably, organic solvents are used which have a flash point which is below their boiling point at atmospheric pressure and which have a boiling point of 100 ° C. or less at an absolute pressure of 1 mbar or more. The organic solvents preferably have a flash point in the range of 40 ° C to 100 ° C. The flash point of particularly suitable organic solvents is in the range of 55 ° C to 100 ° C and more preferably in the range of 61 ° C to 100 ° C.

The cleaning agent preferably also comprises one or more additives selected from the group consisting of surfactants, amines, pH buffers, dispersants, inorganic solvents, such as ammonia solutions or inorganic acids, which have already been pointed out.

In a preferred embodiment of the invention, a mixture comprising as cleaning agent

30-35% by volume of aliphatic hydrocarbon having 9 to 13 carbon atoms;

30-35 vol.% DPM;

1 -5% by volume of diethylamine;

Rest of water

used.

Pressure and temperature are preferably selected in the inventive cleaning method so that no explosive mixture of air and the solvent vapors can form.

In the course of another development of the method according to the invention, it can preferably still be provided that ultrasound is applied to the working chamber and its contents at least during step c) in order to promote the dispersion of the constituents of the cleaning agent and to improve the cleaning effect. In this way, the achievable cleaning effect can be increased.

A corresponding development of the device according to the invention is characterized by ultrasound generating means in operative connection with the working chamber in order to apply ultrasound to the working chamber and its contents.

A preferred "minimum equipment" of the device according to the invention comprises at least one tank (tank means) for the water-solvent mixture, a working chamber for carrying out the actual cleaning, preferably with a circulation for producing a dispersion of the added solvents and the water, and an evaporator to recover the solvent used and the water.

Further features and advantages of the invention will become apparent from the following description of exemplary embodiments with reference to the drawing.

The single figure shows schematically an embodiment of the device 1 according to the invention, wherein optional components are shown in phantom.

The device 1 comprises, in addition to a working chamber 2, at least one detergent tank 3 containing the cleaning agent used (two different solvents and water) ("tank 1"); the further tank-marked tank 4 ("tank 2") is like the corresponding one Line, conveyor, filter and valve means (also shown in phantom) - optional. At least the tank 3 is in fluid communication with the working chamber 2 via suitable line, conveying 5, filter 6.1, 6.2 and valve means (not all designated), so that the cleaning agent from the tank 3 can be introduced into the working chamber 2, for example by flooding (in particular via the fine filter 6.2) or by injection. The working chamber 2 can also be charged with the parts to be cleaned (not shown). It can further be designed to realize a circulation process, so that no segregation of the detergent takes place by the detergent by means of the conveyor (pump) 5 from the working chamber 2 via the filter means 6.1, 6.2 and the working chamber 2 (or the tank 3) again is fed, for which purpose the valve means are to be controlled suitably, which is known in the art.

According to the embodiment shown in FIG. 1, an evaporator 7 is arranged in fluidic operative connection with the working chamber 2, so that a cleaning and recovery of the individual components of the cleaning agent is possible. The filter means 6.1, 6.2 switched into the circulation for the cleaning agent serve to clean the cleaning agent of soiling. The provision of a separate coarse filter 6.1 is not absolutely necessary. The tank 1 has at reference 3a an overflow for the operation of the device 1 in the clean ing of parts oily first, water-insoluble solvent, which overflow 3a is in operative connection with the evaporator 7, to allow continuous operation in operation of the particular solvent in question ,

For the purpose of recovering the water-solvent mixture used or of its constituents, the evaporator 7 is connected to a condenser 8, which in turn is in operative connection with separator means 9 and a vacuum pump 1 0. Separator 9a may be provided to recover the water insoluble solvent, the other separator 9b to recover the water soluble solvent (and water) without limiting the invention to such an embodiment.

At the working chamber 2 can not be arranged ultrasound means shown to urge the contents of the working chamber 2 currency end of the cleaning process with ultrasound. Furthermore, the at least the working chamber includes means for setting a working temperature (not shown).

The working chamber 2 is also directly in operative connection with the evaporator 7 (at reference numeral 7a), u m a vapor phases cleaning of parts to be cleaned - especially after they have been cleaned with the cleaning agent, as described above.

By means of the Vakuumpu mpe 1 0 then a (Vakuu m-) drying of the parts in the working chamber 2 du you rchgeführt. For putting in addition, it can be used to E instellen a certain pressure in the working chamber 2.

In an advantageous optional embodiment of the device 1 with a second tank 4, this tank ("Tan k 2") may be filled with an organic solvent, preferably with a water-insoluble solvent, most preferably the first solvent, which also contains in the cleaning agent used The solvent in tank 4 may contain additives, such as anti-corrosives or lipid-replacers, and the relevant tank k 4 is represented by appropriate piping, conveying 1 1, filter 12 and valve means (shown in phantom, not all designated) ) - in Wirkverbindu ng. Tan k 4 and tank 3 may be cascaded, as shown. Otherwise, the plant part "share" with the tank 3 and the optional plant part with the tank 4 at least the working chamber 2, the evaporator 7, the coarse filter 6.1 and the condenser-separator arrangement 8, 9 with the vacuum pump 10, without the invention would be limited to this.

In operation, the described variant of the device 1 initially works analogously to the variant without tank 4 and the associated further means to perform a cleaning. Subsequently, the relevant solvent can be introduced into the working chamber 2 from the tank 4, for example by injection, in order to keep the consumption small. As a result, water residues can be removed, so-called "dewatering." The solvent used can be removed via the filter means 6.1, 6.2 into the tank 3 and / or the tank 4. Additionally or alternatively, the solvent used can be passed through the water separator 9a If the tank 3 is operated, it will be advisable to supply the solvent at the top, because there will be the relevant solvent layer of the first solvent, after which the working chamber 2 can be (partially) filled with the solvent from tank 4, the solvent being applied to a tank The working chamber 2 can be (partially) evacuated for this purpose, preferably by means of the vacuum pump 10. This helps to evaporate any remaining water remaining on the cleaned parts Coarse filter 6.1 circulated, which can be used for recovery Solvent on the evaporator 7 and the condenser-separator arrangement 8, 9 (the water 9a) are guided.

There may be an additional (hot) water tank for flushing purposes, which is not shown in the figure. In principle, the tank 4 can alternatively be used accordingly. In conjunction with the tank means 3, 4 and / or the working chamber 2 tempering (not shown) may be provided to adjust the temperature of the detergent / solvent targeted.

Claims

claims

Process for the purification of industrially manufactured parts from metal and / or plastic using a cleaning agent, characterized in that a mixture of at least two organic solvents and water is used as cleaning agent, which mixture contains at least one non-water-soluble organ aqueous solvent and at least one water-soluble organic solvent.

Method according to claim 1, with the steps:

a) introducing parts to be cleaned in a working chamber (2); b) loading the working chamber (2) with water and with a solvent mixture containing at least a first water-insoluble, organic solvent and at least one second water-soluble, organic solvent;

c) Clean the parts in the working chamber (2) by means of the water-solvent mixture.

Method according to claim 1 or 2,

dadu rch characterized in that in step c) a rolling of the parts and / or the Wasser-Lösu ngsmittelgemisches in the working chamber (2).

Method according to one of claims 1 to 3,

dadu rch characterized in that at the end of step c) d the parts removed from the working chamber (2) or the water-solvent mixture is discharged from the working chamber (2).

Method according to claim 4,

dadu rch marked that subsequently

The working chamber (2) is evacuated and at least one organic solvent in a vaporous state at a Unterd jerk to the environment, preferably at a pressure of 400 mbar, 200 mbar or lower, with a tempera r at or above the flash point of the relevant Solvent into the evacuated working chamber (2). feeds and the cleaning is completed by condensation of the solvent vapor on the parts, wherein the negative pressure and / or the temperature is chosen such that no explosive mixture is formed.

Method according to claim 4 or 5,

characterized in that subsequently

hot water at a temperature of preferably above 50 ° C in the working chamber (2) is introduced.

Method according to one of claims 4 to 6,

characterized in that subsequently

the cleaned parts are subjected to drying. Method according to claim 7,

characterized in that

the drying in the working chamber (2) takes place.

Method according to one of claims 1 to 8,

characterized in that

after cleaning, the water-solvent mixture is purified by evaporation and / or filtration and prepared for reuse.

Method according to one of claims 1 to 9,

characterized in that

the first solvent having a content of less than 5% by volume, preferably less than 1% by volume, most preferably less than 0.1% by volume, is soluble in water, and

the second solvent is in a proportion of more than 5% by volume, preferably more than 20% by volume, most preferably more than 30% by volume or more than 50% by volume, soluble in water.

Method according to one of claims 1 to 10,

characterized in that

the cleaning agent preferably, based on the proportion of water-soluble of organic solvent, a water content of at least about 10% by volume, preferably at least about 30% by volume, most preferably at least about 50% by volume. contains.

Method according to one of claims 1 to 11,

characterized in that

the water-solvent mixture has a mixing ratio between non-water-soluble solvent and the total of the water-soluble solvent and water of about 10:90, preferably 30:70, most preferably 50:50.

13. The method according to any one of claims 1 to 12,

characterized in that

before step b) the parts are pre-cleaned with a solvent, preferably an organic solvent.

Method according to one of claims 1 to 13,

characterized in that

at least during the steps b) and c) in the working chamber (2) a negative pressure relative to the environment is generated and maintained.

Method according to one of claims 1 to 14,

characterized in that

at least during the steps b) and c) in the working chamber (2) generates and maintains overpressure relative to the environment.

Method according to one of claims 1 to 15,

characterized in that

at least during steps b) and c) a pressure and a temperature is generated and maintained in the working chamber (2) so that no plosionable mixture of air and solvent vapor is formed.

17. The method according to any one of claims 1 to 16,

characterized in that

the organic solvents have a flashpoint in the range of 40 ° C to 100 ° C, preferably 55 ° C to 100 ° C, most 61 ° C to 100 ° C, possess.

18. The method according to any one of claims 1 to 17,

characterized in that

the water-solvent mixture further comprises one or more additives selected from the group comprising surfactants, amines, pH buffers, dispersants, inorganic solvents.

Method according to one of claims 1 to 18,

characterized in that

comprising as a water-solvent mixture a mixture

30-35% by volume of aliphatic hydrocarbon having 9 to 13 carbon atoms,

30-35 vol.% DPM,

1 -5 vol.% Diethylamine and

Rest of water

is used.

Method according to one of claims 1 to 19,

characterized in that

at least during step c), the working chamber (2) and its contents are subjected to ultrasound.

21. Device (1) for cleaning industrially manufactured parts made of metal and / or plastic, in particular according to the method according to one of the preceding claims, comprising:

a) a working chamber (2) for receiving parts to be cleaned; b) tank means (3, 4) for providing water and a solvent mixture comprising at least a first water-insoluble organic solvent and at least a second water-soluble, organic solvent, which tank means (3, 4) for charging the working chamber (2) with the water and the solvent mixture are in fluid communication with the working chamber (2); c) conveying means (5, 1 1) for conveying the water and the solvent mixture in the working chamber (2) for the purpose of cleaning the parts in the working chamber (2) by means of the water-solvent mixture.

22. Device (1) according to claim 21,

further characterized by

Filter means (6.1, 6.2, 12) for the water and for the first and second solvents in fluid communication with the tank means (3, 4) and the working chamber (2).

23. Device (1) according to claim 21 or 22,

further characterized by

Evaporator means (7) and condenser means (8) in fluid communication with the tank means (3, 4) and the working chamber (2).

24. Device (1) according to one of claims 21 to 23,

further characterized by

Depositing means (9, 9a, 9b) in fluid communication with the evaporator (7) and condenser means (8).

25. Device (1) according to one of claims 21 to 24,

further characterized by

Pressure generating means (10) in Fiuidverbindung at least with the evaporator (7) and / or capacitor means (8) and / or with the working chamber (2).

26. Device (1) according to one of claims 21 to 25,

further characterized by

Ultrasonic generating means in operative connection with the working chamber (2).