JP2002522647A - Automatic adjustment and control of cleaning bath - Google Patents

Abstract

  (57) [Summary] A method for monitoring a cleaning bath, wherein at least two analyzes of (i) surfactant content analysis, (ii) inorganic carbon and / or total organic carbon loading analysis, and (iii) alkalinity analysis are programmed. (B) starting additional supply of supplemental components and / or one or more bath treatment means, based on the results of the analysis; and / or A method characterized in that a result of the analysis and / or data derived from the result of the analysis is sent to a location located at a different location from the device for performing the analysis.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a cleaning bath, especially a cleaning bath in the automobile manufacturing industry or the metal processing industry.
Cleaning bath).
The essence of the invention is that at least two parameters are automatically analyzed in a program-controlled manner, and the results of the analysis and / or the data derived from the results of the analysis are separated from the vicinity of the cleaning bath. It is to send to the place. Based on the results of the analysis, in a program-controlled manner or in response to requests from remote locations,
Further analysis and / or bath treatment measures can be initiated. Furthermore, based on the results of the analysis, the control means can be started in a program-controlled manner or on demand. In this case, the remote location may be set, for example, at a higher process control system, at the control center of the plant where the cleaning bath is located, or at a location outside the plant.

[0002] Cleaning metal parts before further processing is a standard practice in the metal processing industry. Metal parts may be contaminated, for example, by pigment stains, dust, metal grind, corrosion protection oils, refrigerants or deformants. Prior to further treatment, for example, prior to corrosion protection (eg, phosphating, chromating, anodizing, reactions with fluoride complexes, etc.), or prior to painting, these impurities are properly cleaned. Need to be removed by the oxidizing solution. For this purpose, a spraying, dipping or compounding process can be used.

[0003] Industrial detergents in the metal processing industry are generally alkaline (pH in the range of 7 or more, for example in the range of 9-12). The basic components of these cleaning agents are alkalis (hydroxides of alkali metals, carbonates, silicates, phosphates,
Borate), and nonionic and / or anionic surfactants. Detergents may comprise, as additional auxiliary components, complexing agents (gluconates, polyphosphates, salts of amino acids, such as ethylenediaminetetraacetate or nitrilotriacetate, salts of phosphonic acids, such as hydroxyethanediphosphonic acid, phosphonobutanetricarboxylic acid Or other phosphonic or phosphonocarboxylic acids), corrosion protection means, for example salts of carboxylic acids having 6 to 12 carbon atoms, alkanolamines and foam inhibitors, for example closed ends having 6 to 16 carbon atoms in the alkyl group. It may contain alcohol or alkoxylate having a group. If the cleaning bath does not contain a nonionic surfactant, a cationic surfactant can also be used.

[0004] Detergents are generally nonionic surfactants, such as ethoxylates, propoxylates and / or ethoxylates of alcohols or alkoxylates having 6 to 16 carbon atoms in the alkyl radical with closed end groups. / Propoxylate. Alkyl sulfates and alkyl sulfonates are widely used as anionic surfactants. Alkylbenzenesulfonates can also be of interest, but these are problematic from an environmental point of view. In particular, cationic alkyl ammonium compounds having at least one alkyl group and 8 or more carbon atoms are suitable as cationic surfactants.

[0005] The alkali in the cleaning bath contributes to the cleaning ability of the cleaning bath. For example, alkalis saponify impurities, such as fats, thereby rendering them water-soluble. These provide for the removal of insoluble dust particles from metal surfaces,
The adsorption of H ions imparts a negative charge to the surface, thereby causing an electrostatic repulsion. As a result of such a reaction, and possibly by its effects,
The alkalinity is consumed and over time the cleaning action disappears. Thus, conventionally, the alkalinity of the cleaning bath is checked at a predetermined time and, if necessary, is replenished with a new active ingredient or completely refreshed. The check is done manually
Alternatively, the measurement is performed partially using an automatic titrator. In this case, the alkalinity is checked, generally by titration with a strong acid. The operator evaluates the alkalinity based on the acid consumption and initiates the necessary measures, such as replenishing the bath or renewing the bath. This conventional method today requires the operator to be near the cleaning bath for the required monitoring time. The shorter the required monitoring interval, the greater the demand on the operator for monitoring measurements. EP-A-8
No. 06244 discloses a method for automatically analyzing the pH of a solution and automatically adding (administering) an acid or alkali solution when the solution deviates. The purpose in this document is to maintain the pH of the liquid flow at a predetermined value. In this method, no acid-base titration was performed. It is necessary to monitor the functional characteristics of the plant on site. The pH measurement process and the means of administration cannot be intervened remotely.

[0006] It is known in the prior art to manually analyze nonionic surfactants, for example, in an aqueous treatment solution in a cleaning bath, using a color indicator. Traditionally, this has been done by adding a reagent that forms a colored complex with a nonionic surfactant to a sample taken from the process solution. The colored complex is preferably extracted into an organic solvent that is not compatible with water in all proportions, and the absorption of light at a specific wavelength is measured photometrically. For example, tetrabromophenolphthalein ethyl ester can be used as a reagent for forming a colored complex. Prior to extraction into the organic solvent, preferably into the chlorinated hydrocarbon, a buffer system to pH 7 is added to the treatment solution.

[0007] It is also known to analyze nonionic surfactants in the presence of ionic surfactants. In this case, the ionic surfactant is separated from the sample by the ion exchange device. Nonionic surfactant not bound to the ion exchanger is analyzed by refractive index on the solution exiting the exchanger column. Preferably, the refractive index is measured as a function of the elution time, the whole (integral) of the part of the curve deviating from the refractive index of the pure eluent is determined, and this total (integral) is compared with the value obtained from the calibration measurement. Compare.

[0008] In another embodiment, the method includes measuring an extreme value of the refractive index and comparing it to a calibration curve to determine the surfactant content therefrom. Anionic and cationic surfactants in aqueous solutions are described, for example, in "Hyamin
(Registered trademark) 1622 "(= N-benzyl-N, N-dimethyl-N-4 (1,1,3,3
-Tetramethyl-butyl) -phenoxy-ethoxyethylammonium chloride) and potentiometric endpoint measurement. For this purpose, a known amount of Na-dodecyl sulphate is added to the sample, titration is carried out using Hyamin, and the end point of the titration is determined using an ion-sensitive electrode.

In another embodiment, the anionic surfactant can be analyzed by titration with 1,3-didecyl-2-methylimidazolium chloride. An electrode having an ion-sensitive membrane is used as a detector. The potential of the electrode is a function of the concentration of the measured ion in the solution. Although this surfactant analysis involves significant expenditure in terms of personnel costs, plant workers add one or more additional components to the process solution based on the results. The method thus requires an operator at the plant location, at least at the time of the surfactant analysis. Therefore, it is personnel intensive, especially in the case of multi-level operation. Further expenditures are required to document the results on quantity control and quantity reservation.

[0010] As a result of the cleaning process, soil components detached from the surface accumulate in the cleaning solution. Pigment soiling can lead to loading of inorganic carbon. Corrosion protection oils, cooling lubricants or deforming agents, such as drawing grease, and / or dissolved or extracted organic coating materials, etc., can lead to the loading of total organic carbon in the cleaning solution. Most of this total organic carbon is present in the form of mineral oils, mineral fats or fats derived from animal or vegetable oils, so "fat loading" of the cleaning solution
Most of such fats are present in emulsified form in the cleaning solution. However, fats of animal or vegetable origin are at least partially removed by the alkaline cleaning solution. Hydrolysis products may also be present in dissolved form in the cleaning solution.If the total organic carbon loading in the cleaning solution is high, fats should be cleaned. It will not be possible to ensure that the cleaning solution is liberated to the extent necessary for the components, otherwise,
When the cleaned part is removed from the cleaning solution, it is possible for grease to adhere back to the cleaned part. Therefore, it is necessary to keep the fat loading of the cleaning solution below a critical maximum, which may depend on the further use of the cleaned part and the components of the cleaning solution. In the case of high fat loading, it is also possible to increase the surfactant content of the cleaning solution in order to improve the fat dissolving ability of the cleaning solution. Alternatively, the bath treatment is started to reduce fat loading of the cleaning solution. This is necessary in any case at the predetermined upper limit of fat loading. In the simplest case, the cleaning solution is partially or completely disposed of and replaced or replaced by a fresh cleaning solution. However, due to the wastewater thereby generated and the need for fresh water, it is necessary to separate the fats and oils from the cleaning solution and to continue to use the cleaning solution, possibly supplemented with active ingredients. Can be Devices suitable for this purpose, such as separators or membrane filtration devices, are known in the art.

Conventionally, it is common practice to visually evaluate the cleaning efficiency of a cleaning solution based on the result of cleaning. The plant operator evaluates the cleaning efficiency and takes necessary measures, such as refilling or renewing the bath. This current routine operation requires the operator to be near the cleaning solution for the required monitoring time. The shorter the required monitoring interval, the greater the demand on the operator for a visual evaluation.

In the prior art, individual control parameters of the cleaning solution are analyzed in a programmed manner, the results of the analysis are sent to a remote location, and based on the results of the analysis,
It has already been proposed to start the control measurement and / or bath treatment means from a remote location or automatically in a programmed manner. A method for automatically monitoring and controlling the surfactant content in the process aqueous solution is described in H3267 and describes the loading of carbon-containing compounds in the cleaning aqueous solution.
The automated analysis of the cleaning solution is described in H3268, and the automatic monitoring and control of the cleaning solution by alkalinity analysis is described in German Patent Application DE 198 02 725.7. The present invention is based on these methods in that they are related to these applications. The methods by which individual analyzes can be performed are described in detail in the above three documents. Accordingly, the contents of these three documents are considered to be part of the disclosure content of this specification.

It is an object of the present invention to facilitate monitoring, and preferably control, of a cleaning bath without requiring an operator to be at the location of the cleaning bath. The measuring device used preferably has a self-check function and a self-calibration function, and preferably sends an alarm signal to a remote place in the case of failure. Furthermore, it is preferred that the functional properties of the measuring device and the result of the measurement can be checked from a remote point. Furthermore, the measuring process and the bath treatment means can be intervened from remote points. Desired remote monitoring reduces personnel costs for bath control and bath monitoring of the cleaning bath. In this case, at least two parameters can be analyzed, from which the soil loading and / or functional properties of the cleaning bath can be detected. By taking into account several measured variables, a more purposeful bath treatment means can be started than is possible if only one measured variable is known.

[0014] The purpose of this is to programmatically control at least two of the following analyzes: (i) analysis of surfactant content; (ii) analysis of inorganic and / or total organic carbon loading; and (iii) analysis of alkalinity. (A) depending on the results of the analysis, additional supply of supplemental components and / or starting one or more bath treatment means; and / or (b) results of the analysis and / or Alternatively, it is achieved by a method of monitoring a cleaning bath, characterized in that the data resulting from the analysis is sent to at least one remote location located at a location different from the location of the device performing the analysis.

For example, both surfactant content and inorganic and / or total organic carbon loading can be analyzed. Alternatively, the surfactant content and alkalinity can be analyzed. Alternatively, loading and alkalinity of total organic and / or inorganic carbon can be analyzed. However, in order to fully understand the current state of the state of the cleaning bath, it is preferable to analyze all three parameters. Certain methods of performing these analyzes in a program-controlled manner are described in detail in the aforementioned references. The analysis can be performed substantially simultaneously or sequentially.

The result of the analysis can be recorded on an information storage medium. Additionally or alternatively, the result may be the basis for further calculation. The result of the analysis or the result of the further calculation is the remote destination ("remote location (rem
ote location) "), where it is recorded and / or output again on the information storage medium. "Remote location" or "remote location" for the method of the present invention
When referred to, it should be understood that these terms are not locations that are in direct contact with the processing solution, or at least not locations that are directly visible. The distant point, for example, as part of the overall process for surface treatment of metal articles,
It may be a central process control system or the like that monitors and controls the cleaning bath as a division of business. The “remote point” may be a monitoring control center that performs monitoring and control of the entire process, and may be arranged in a room separate from the processing bath, for example. The "remote point" may be outside the plant where the cleaning bath is located. In this way, a specialist outside the plant in which the treatment bath is located can check and control the treatment bath. As a result, there are very few cases where an expert needs to be at the cleaning bath location.

Suitable data lines through which analysis results and control commands can be communicated are available from the prior art. "Outputting the results of an analysis or the results of further calculations" is understood to mean sending the results to a higher-level process control system or displaying them on a screen or printing them out for human understanding. Should be. The point where the result is displayed or output on the screen
It may correspond to a “distant point”. It is preferred that the results of individual analyzes recorded on the information storage medium at least at predetermined time intervals can be subsequently evaluated, for example in the form of a quality assurance check. However, the result of the analysis need not necessarily be output directly or recorded on the information storage medium. The results of those analyzes can be used directly as a basis for further calculations, or the results of those further calculations can be displayed or recorded. For example, instead of the content at that time, the trend of the concentration or their relative change can be displayed on the screen. The content at that time is referred to as "% of the standard content.
Or "% of maximum content".

[0018] In this case, the remote location is at least 5 minutes away from the device for performing the analysis.
It may be located at a distance of 00 m. In particular, the location may be located outside the plant where the cleaning bath to be monitored is operated. In this way, remote monitoring is provided without requiring an operator to be in close proximity to the cleaning bath.

Here, when a new analysis result and / or data derived from the analysis result is obtained, the analysis result and / or data derived from the analysis result are automatically transferred to a remote location. Set to communicate to In another aspect, the transmission of the results of the analysis and / or the data derived from the results of the analysis to a remote location may be set to occur on demand from the remote location.

On the other hand, each analysis is repeated at predetermined time intervals. Alternatively, the process control system can be configured to repeat each analysis at shorter time intervals if the difference between the results of two consecutive analyzes is greater. Here, the analysis of the second measurement variable is started when the analysis of the first measurement variable is within a predetermined critical value or when a predetermined change occurs in the value between the two analysis of this measurement variable. You can also set to do. Thus, the start of the analysis of one measurement variable can depend on the result of the analysis of another measurement variable.

[0021] In other words, the method of the present invention is characterized in that the first analysis selected from analysis (i), (ii) and (iii) determines whether the value exceeds a predetermined maximum value or falls below a predetermined minimum value, Alternatively, the second analysis selected from the analysis (i), (ii) and (iii) is performed in a program-controlled manner when a result is obtained which deviates from the immediately preceding result of the first analysis by a predetermined minimum value. Can be implemented. As a matter of course, the analysis can be set to be performed in response to a request from a remote place.

In one embodiment, the method of the invention comprises, in a program-controlled manner, (i) performing an analysis of surfactant content, comprising: (a) collecting a predetermined amount of sample from the aqueous treatment solution; (B) separating, if desired, the solid material from the sample; (c), if desired, bringing the sample to a predetermined rate or a rate determined by the results of a preliminary analysis. (D) separating and stripping the volatile compounds by selective adsorption, electrochemical and chromatographic methods for the analysis of the surfactant content; and detecting the volatile compounds. Or by altering the interaction of the sample with the electromagnetic radiation in proportion to the surfactant content and measuring the change in this interaction.

Another aspect of the method of the present invention is that (ii) analyzing the loading of inorganic carbon and / or total organic carbon in a program-controlled manner, comprising: (a) cleaning aqueous solution (B) separating solid material from the sample, if desired, and / or homogenizing the solid material; (c) presetting, if desired, Diluting the sample with water to the proportions determined by the proportions or the results of the preliminary analysis; and (d) analyzing the inorganic carbon and / or total organic carbon content in the samples using known methods. And

Depending on the form of sub-step (d), inorganic carbon (IC), total organic carbon (TOC)
), Or their sum. As part of the analysis, if only the lipophilic substance is extracted from the cleaning solution and an extraction method that can be analyzed in the subsequent steps is used, the ratio of the lipophilic substance in the cleaning bath should be detected. Can also. Another aspect of the invention is (iii) analyzing the alkalinity of the cleaning bath in a program-controlled manner by acid-base reaction using an acid, comprising: (B) separating solid material from the sample, if desired; (c) selecting whether free alkalinity and / or total alkalinity should be analyzed; and (D) titrating a sample by adding an acid, or titrating by a sample using an acid as a starting material.

The amount of sample taken in each sub-step (a) can also be pre-programmed into the control section of the measuring device used in the method. It is also preferred that the size of the sample volume can be varied from a remote point. In addition, the control program can be set to determine the amount of sample to be used, depending on the results of previous measurements. For example, if the content of the substance to be analyzed in the cleaning bath is small,
The sample volume can also be selected to be large. Therefore, the accuracy of the analysis can be optimized.

It is preferred to separate the solid material from the sample in each optional sub-step (b) between the sampling and the actual measurement. This step is not necessary if the solids loading of the cleaning solution is very small. However, if the solids content is high, the valve of the measuring device can be closed or the sensor can be contaminated. Therefore, it is advantageous to separate the solid material from the sample. This can be done automatically by filtration or by using a cyclone or centrifugation.

Prior to analysis of the selected parameters, if desired, the sample is diluted with water to a preset ratio or to a ratio determined by the results of a preliminary analysis. In sub-step (d), the actual analysis is performed according to various methods as described below.

In the simplest case, the method of the present invention is operated to repeat a particular analysis after a predetermined time interval. The predetermined time interval depends on the requirements of the operator of the processing solution and may be a desired time interval ranging from minutes to days. To ensure quality, the predetermined time interval may be, for example, in the range of 5 minutes to 2 hours. For example, the measurement can be performed every 15 minutes.

The method of the present invention provides that if the difference between the results of two consecutive analyses is greater,
It can also be performed to repeat a particular analysis at shorter time intervals.
Thus, the control system for the method of the invention can itself determine whether the time interval between individual analyzes should be lengthened or shortened. Of course, the indication information about the time interval to be selected when there is a difference between successive analyzes has to be preset in the control system.

Here, two or three analyzes selected from the analyzes (i), (ii) and (iii) do not always need to be always performed in this sequence. One analysis may be performed more frequently than another. It may be the case that one parameter is actually shown to change more rapidly than the other parameters. For example, surfactant content can be analyzed more frequently than alkalinity. Alternatively, the decision whether to perform another analysis can be programmed to be based on the results of the first analysis. For example, it may be set so that the analysis of alkalinity is not performed until the carbon content of the cleaning bath exceeds a predetermined limit value. Or
The alkalinity analysis may be performed only when the surfactant content of the cleaning bath is below a predetermined lower limit. In this way, it is possible to select, for example, whether it is necessary to add only a surfactant component or a builder component to the cleaning bath.

Further, the method of the present invention can be carried out in such a manner that a specific analysis is performed at a desired time according to an external request. In this way, rapid monitoring of the detergent content, alkalinity and / or fat loading of the cleaning solution can be performed if quality problems are identified in subsequent process steps.
The measurement of the selected analytical variables is thus performed in a time-controlled manner (fixed time intervals) or in an event-controlled manner (after a change has been confirmed Can be done).

I) Analysis of Surfactant Content The method of the present invention can be configured such that the surfactant whose content in the processing solution is to be analyzed is a nonionic surfactant. Regarding the analysis of such a surfactant, in the sub-step (d), the interaction between the sample and electromagnetic radiation is changed in proportion to the content of the nonionic surfactant, and the change in this interaction is changed. Can also be added to determine the amount of

For example, the reagent may consist of a complex of two substances A and B, in which case the nonionic surfactant replaces substance B with the substance A and It may form a complex and thus change the color or fluorescent properties of substance B. For example, the substance B may form a dye or a fluorescent substance capable of forming a complex with, for example, dextran or starch as examples of the substance A. As a component of the complex, substance B has a particular color or fluorescent property. If this component is replaced from the complex, these properties will change. By measuring light absorption or fluorescence radiation, it is possible to detect how much of the substance B has not formed a complex with the substance A. In this case, substance A is selected so that substance B is displaced from the complex by adding a nonionic surfactant, and instead forms a complex with the nonionic surfactant. Thus, the amount of substance B excluded from the complex with substance A is proportional to the amount of nonionic surfactant added. From the change in fluorescence or absorbance caused by the amount of the separated substance B, the amount of the added nonionic surfactant can be estimated.

For example, a salt of a cationic dye containing a tetraphenylborate anion can be used as a reagent. The nonionic surfactant can exclude the dye from this salt when converted to a cationic complex with barium by adding barium ions. This method of converting a nonionic surfactant to a positively charged complex and thus making it available for the reaction in response to a cation is known in the art as "activation" of a nonionic surfactant. It is called.
This method is described, for example, by Vytras K., Dvorakova V and Zeeman I in "Analyst
114, p. 1435 et seq. (1989). The amount of cationic dye released from the reagent is proportional to the amount of nonionic surfactant present. During this release, the dye's absorption spectrum If a change occurs, the amount of dye released can be analyzed by measuring the appropriate absorption band photometrically.

This assay uses as a reagent a salt of a cationic dye that is soluble only in an organic solvent that is immiscible with water, while the released dye itself is water-soluble and If the phase is colored, it can be simplified. Of course, it is also possible to adopt the opposite arrangement: using a water-soluble salt of an organic dye, wherein the dye to be released is only soluble in the organic phase. By releasing the dye for exchange with a nonionic surfactant and extracting each released dye into a separate phase, the dye can be analyzed optically in a simple manner. This analysis method is also suitable for the analysis of a cationic surfactant. In that case, the above-mentioned "activation" by the barium cation is not necessary, since the cationic surfactant is already positively charged.

In addition, the reagents can include substances that form complexes with the anionic surfactants having different color or fluorescent properties to become free reagents. For example, the reagent may be colorless in the optical domain, and the complex with the nonionic surfactant may absorb electromagnetic vibrations in the optical domain and thus have a color. Alternatively, the maximum value of the light absorption of the unbound reagent, and thus the color, is different from the color of the complex with the nonionic surfactant. However, the reagents can also exhibit certain fluorescent properties that change when they form a complex with a nonionic surfactant. For example, a free agent has fluorescent properties and can also lose its fluorescent properties by forming a complex with a nonionic surfactant. In all cases, the concentration of the complex of the nonionic surfactant and the reagent can be analyzed by measuring the light absorption at the wavelength to be measured or by measuring the fluorescent radiation, and thus the nonionic surfactant The concentration of the agent itself can also be analyzed.

Preferably, in sub-step (d), the reagent is added to form a complex between the reagent and the nonionic surfactant, and the complex is converted to an organic solvent that is immiscible with water in any proportion. Can be extracted inside. The complex of the nonionic surfactant and the added reagent is then extracted into an organic solvent that is immiscible with water in all proportions. This can be done by mixing the two phases vigorously, for example by infiltration or preferably by stirring. After this extraction step, the mixing of the two phases is terminated, causing a phase separation between the aqueous phase and the organic phase. If desired, the integrity of the phase separation can be monitored by any suitable means (measurement), for example by measurement of turbidity by light absorption or scattering or by analysis of electrical conductivity (measurement).

After this operation, an actual measurement of the nonionic surfactant content is made. For this purpose,
The organic phase containing the complex of the nonionic surfactant and the added reagent is exposed to electromagnetic radiation that can interact with the complex dissolved in the organic phase. For example, visible light or ultraviolet light can be used as the electromagnetic radiation, and the absorption of the complex by the nonionic surfactant and the added reagent is analyzed. However, for example, it is also conceivable to use an agent whose complex with a nonionic surfactant provides a characteristic signal in nuclear magnetic resonance or electron spin resonance. The intensity of the signal can also be related to the concentration of the complex, expressed as a reduction in electromagnetic oscillations in the appropriate (absorption) frequency band. Instead of the absorption effect, the concentration can be analyzed using the emission effect.
For example, select a reagent whose complex with a nonionic surfactant in an organic solvent absorbs electromagnetic radiation of a specific wavelength, and instead emits electromagnetic radiation of a longer wavelength, and whose intensity can also be measured. You can also. An example in this regard is to measure fluorescent radiation when illuminating the sample with visible or ultraviolet light.

In principle, the mixing of the interaction between the organic solvent and the electromagnetic radiation can be carried out immediately after completing the phase separation, in the same vessel in which the phase separation has taken place. However, depending on the measurement method used to analyze the interaction of the organic phase with the electromagnetic radiation, it is preferred to direct or supply the organic phase or part thereof through a line to the actual measuring device. In particular, in this way, a suitable cuvette for the measurement can also be provided. Therefore, a preferred embodiment of the present invention is to separate the organic phase from the aqueous phase and supply it to the measuring device according to sub-step (f). For this separation of the organic phase, it is particularly advantageous that the organic solvent, which is immiscible with water in all proportions, consists of a halogen-containing solvent having a higher density than water. After phase separation, the organic phase is located in the lower part of the vessel,
Can be extracted from the bottom part.

For example, dichloromethane or halogenated hydrocarbons with a higher boiling point, in particular chlorinated fluorocarbons, for example trifluorotrichloroethane, are used as halogen-containing solvents. After use, these solvents must be disposed of in accordance with local regulations. Since this is costly, the used solvent can be reprocessed, for example, treated with activated carbon, and / or distilled and reused in the measurement process.

In a preferred embodiment of the present invention, a substance which causes a color reaction with a nonionic surfactant in an organic phase can be added as a reagent. Light absorption at a given wavelength can also be measured as the interaction of electromagnetic radiation with an organic phase. Conventional photometers are also suitable for this purpose. For example, it is necessary to add a buffer system in the region of pH 7 to the sample of the treatment aqueous solution. Such a buffer system may consist, for example, of an aqueous solution of hydrogen phosphate and dihydrogen phosphate. In this case, the operation is preferably performed so that the amount of the buffer solution substantially exceeds the amount of the surfactant-containing treatment solution of the sample.

When using tetrabromophenolphthalein ethyl ester as a color reagent, the measurement of light absorption in sub-step (g) is 610
It is preferably performed at a wavelength of nm. In a preferred embodiment using 3,3,5,5-tetrabromophenolphthalein ethyl ester as a color former, the content of nonionic surfactant can be analyzed as follows: 3,3 in 100 ml of ethanol. An indicator solution containing 100 mg of 3,5,5-tetrabromophenolphthalein ethyl ester is prepared. A buffer solution is also prepared by mixing 200 ml of a commercially available buffer solution (potassium dihydrogen phosphate / disodium hydrogen phosphate) for adjusting pH 7 and 500 ml of a trimolecular potassium chloride solution in 1000 ml of water.

To perform the analysis, start with 18 ml of the buffer solution in a suitable container. 2 ml for this
Add indicator solution. To this is added 50 μl of sample solution. After stirring the mixed solution for 3 minutes, 20 ml of dichloromethane are added. Then, put the medicine 1
Mix vigorously for minutes. Thereafter, it takes about 20 minutes, for example, but waits for phase separation. Thereafter, the organic phase is separated and measured at a wavelength of 610 nm with a photometer. As a cuvette for analysis, for example, a 10 mm cuvette is suitable. The surfactant content of the sample solution is determined with reference to the calibration curve. If the analysis is unreliable due to low surfactant content, the amount of sample used for the measurement (v
olume) can be increased. If the surfactant content is high and the light absorption exceeds 0.9, it is advantageous to dilute the sample before measurement.

Regardless of the method selected, the correlation between the concentration of the nonionic surfactant and the intensity of the measurement signal is established by performing a calibration in advance using a known concentration of the surfactant solution, Need to be recorded. When measuring light absorption, calibration can also be performed with a suitable colored glass. Deriving the surfactant content of the sample by adding a known concentration of surfactant / agent complex or by multiplexing and remeasurement of the interaction with electromagnetic radiation instead of a prior calibration. it can.

Instead of analyzing the interaction of the agent or complex bound by the nonionic surfactant with electromagnetic radiation from the agent or complex binding to the nonionic surfactant, it is analyzed chromatographically for the content of nonionic surfactant. It is also possible. For this purpose, it is preferable to first separate the fats and oils that may be present in the sample. Thereafter, the sample, which may optionally comprise an ionic surfactant, is fed to an anion and / or cation exchange column, preferably in the form of a column for high pressure / liquid chromatography. The concentration of the nonionic surfactant in the solution is preferably analyzed by separating the ionic surfactant, discharging the ionic surfactant from the exchanger, and measuring the refractive index. In this case, it is preferable to perform quantitative evaluation by an external standard method. The measurement is carried out by comparing the solvent containing the substance to be analyzed from the measuring cell of the detector with the pure solvent from the control cell. Water or water-methanol mixture is used as the solvent.

Before starting a series of measurements, it is necessary to calibrate the ion exchange system in HPLC form and flush the detector control cell with solvent for 20 minutes.
For calibration, solutions with different concentrations of nonionic surfactant to be analyzed are used. The calibration solution and the sample solution need to be degassed in an ultrasonic bath for 5 minutes before being injected into a system, for example, in HPLC form. The defined degassing is important for the refractive index sensitivity for different solvent qualities.

If methanol is added to the sample solution before transfer to an ion exchange column in HPLC form, insoluble salts may precipitate. Before supplying this sample to a system in the form of HPLC, it is necessary to filter the sample with a micro filter or the like. This method is known for off-line analysis of unsulfonated (unsulfated) components in organic sulfates or sulfonates (DIN EN 8799).

The following method is also suitable for the analysis of nonionic surfactants: The nonionic surfactant is separated from the hydrogen halide, preferably hydrogen iodide, to form a volatile alkyl halide, preferably iodide. This produces an alkyl. Volatile alkyl halides are separated by blowing a gas stream into the sample and detected in a suitable detector. An "electron capture detector" is an example of a suitable detector for this purpose. This method is known as a laboratory method characteristic of fatty alcohol ethoxylate (DGF Standard Method H-III17 (1994)). The surfactant may be an anionic surfactant. The content in the sample solution is analyzed in sub-step (d), preferably electrochemically. For this purpose,
The anionic surfactant is titrated with a suitable reagent, after which a change in the electrical potential of the suitable measuring electrode occurs.

For example, in this case, the pH of the sample is set in the range of 3 to 4, preferably about 3.5, the sample is titrated with a titrant in the presence of an ion-sensitive membrane electrode, and the electrode potential is measured. The change in is measured. The sensitivity of this method can be improved by adding an alcohol having 1 to 3 carbon atoms, preferably an alcohol containing methanol to the sample. 1,3-Didecyl-2-methylimidazolium chloride is a preferred and preferred titrant. An ion-sensitive membrane electrode, preferably a membrane electrode with a PVC membrane, acts as a measuring electrode. Such electrodes are known as "high sensitive electrodes"
sense electrode). A silver electrode is preferably used as a reference electrode. The potential is created by an interaction as specific as possible between the ions in the measuring solution to be analyzed and the ion carriers contained in the PVC membrane. This interaction results in the transfer of the measured ions from the measured solution into the membrane in the form of an equilibrium reaction, thus creating a difference in the electrical potential at the measured solution / membrane phase boundary. This difference in potential can be measured potentiometrically (independently of the current) using a reference electrode.
The extent to which ions flow from the measured solution into the membrane depends on the concentration. The relationship between the measured ion concentration and the electrical potential is theoretically explained by the Nernst 'equation. However, it is preferred that the relationship between the electrode potential and the measured ion concentration be determined by calibration using a control solution, due to possible disturbances and the like.

Apart from anionic surfactants, cationic surfactants can also be analyzed in the processing solution to be monitored. For this purpose, a method suitable for the analysis of anionic surfactants can be used. In this method too, the analysis is performed electrochemically: a predetermined amount of Na-dodecyl sulphate is added to the sample and Hyamin (N-
The sample is titrated with benzyl-N, N-dimethyl-N-4 (1,1,3,3 tetramethyl-butyl) -phenoxy-ethoxyethylammonium chloride) and an electrode sensitive to ionic surfactants Use to determine the end point of the titration.

In addition to the methods already described, a method of adsorbing a surfactant to a suitable surface and measuring the effect of the surfactant coating the surface is also suitable for the analysis of the surfactant. Coating the surface with a surfactant below the saturation limit can be considered to be proportional to the surfactant concentration, so after properly calibrating, the surfactant- The content can be estimated.

For example, a surfactant can be adsorbed on the surface of a crystal oscillator, and a change in the oscillation frequency of the crystal oscillator can be measured. Alternatively, an optical conductor
The surfactant can be adsorbed on a suitably pretreated surface of the (optical conductor). This results in a change in the refractive index when light passes from the optical conductor to the surrounding medium, resulting in a change in the conductivity of the optical conductor for light. Depending on the index of refraction, light in the optical conductor may be attenuated to varying degrees or, if total internal reflection is lost, no longer appear at the end of the optical conductor. By comparing the light intensity obtained from the end of the optical conductor with the light intensity provided at the beginning of the optical conductor, it is possible to determine the extent to which the surface of the optical conductor is covered by the surfactant, Therefore, the concentration of the surfactant in the surrounding medium can be determined. At certain thresholds of surfactant concentration, total reflection decay occurs, which can likewise be used to characterize the surfactant content of the processing solution.

Ii) Analysis of carbon loading Analysis of the loading of inorganic and / or total organic carbon is described in German Patent H32
68 can be performed as described in detail. Prior to analysis of this parameter, it is advantageous to homogenize the sample, for example by vigorous stirring. As a result, organic impurities considered to be present in the form of coarse oil droplets can be uniformly and finely distributed. If necessary, in sub-step (c), dilute the sample with water at a certain ratio. This ratio can be fixed or can be changed from a remote point. However, the dilution ratio can also be determined depending on the results of a preliminary analysis of the content of inorganic carbon and / or total organic carbon. This ensures that the carbon content of the sample solution is in a range that allows for optimal analysis using the selected method. In sub-step (d), the inorganic carbon and / or total organic carbon, for example, it is converted to CO _2, the resulting CO ₂ can be analyzed by quantitative measurements.

The conversion of carbon to CO ₂ by oxidation can be performed, for example, by burning at high temperature in the gas phase. Preferably, the high temperature during combustion is above about 600 ° C, for example about 680 ° C. The combustion is preferably performed using oxygen gas or air in a reaction pipe using a catalyst. Suitable catalysts include, for example, noble metal oxides or other metal oxides, such as vanadate, vanadium oxide, chromium oxide, manganese oxide or iron oxide. Platinum or palladium attached to aluminum oxide can also be used as a catalyst. This method can directly provide CO ₂ containing combustion gas can be measured CO ₂ content therein as described below.

Instead of combustion in the gas phase, the conversion of carbon to CO ₂ by wet chemistry can also be carried out. In this case, a strong chemical oxidizing agent, such as hydrogen peroxide or peroxodisulfate, is used to oxidize the carbon of the sample. If desired, this wet chemical oxidation reaction can be promoted using a catalyst of the type described above and / or using ultraviolet light. In this case, if necessary, it is preferable to remove generated CO ₂ from the acidified sample for quantitative measurement by an air stream. Bonded carbon in the form carbonate or CO ₂ can also be detected similarly.

Irrespective of the method by which gaseous CO ₂ is produced, it can be measured quantitatively by one of the following methods. If the sample volume is known, then the inorganic carbon and / or total organic carbon content in the cleaning solution can be calculated. Alternatively, if the inorganic carbon is not present or has been removed, the results of the analysis are given in the form of fat loading per liter of cleaning bath, using a predetermined conversion factor.

Various methods known in the prior art can be used to analyze the CO ₂ content of the resulting air stream. For example, a gas can be passed through the sorbent solution, and the weight increase of the sorbent solution can be measured, for example. For example, CO ₂
An aqueous solution of potassium hydroxide, which absorbs water to form potassium carbonate, is suitable for this purpose. Another way to measure weight gain is to measure the change in conductivity of the absorbing solution, or to measure the change in alkalinity after CO ₂ absorption.

The produced CO ₂ can be absorbed by a suitable solid substance and the increase in weight can be measured. For example, soda asbestos is suitable for this purpose. Of course, by using the absorbent solution and a solid absorber, when no longer be bound longer CO _2, it is necessary to replace both the absorbent solution and a solid absorber. However, it is easier to measure the CO ₂ content of the gas quantitatively by measuring the infrared absorption for an automated process. The measurement of infrared absorption can be performed, for example, at a wavelength of 4.26 μm (corresponding to a wave number of 2349 cm ⁻¹ ). Devices capable of measuring infrared absorption and burning a sample are known from the prior art. Shimadzu's TOC system is one example.

As the optical analysis of the CO ₂ content of the gas and the combustion gas discharged from the sample, not only an infrared spectrometer operating in a dispersive manner but also a non-dispersive photometer can be used. It is known as a "NDIR (non-dispersive infrared analyzer)" device. Such a device is described, for example, in DE-A-4405 881. In this analytical method, the proportion of carbon obtained from the intentionally added active ingredient in the cleaning solution is detected. Such examples include surfactants, organic corrosion inhibitors and organic complexing agents. However, their content in the cleaning solution is also known as being within certain limits of variation, but can be defined independently. The percentage of total organic carbon derived from these active ingredients can be subtracted from the results of the analysis. Therefore, the ratio obtained from the mixed impurities is determined. In fact, in this case, it is not very important in the carbon analysis to take into account the proportion of carbon present in the form of the active ingredient. Rather, it is often sufficient to fix the upper limit of the carbon content of the cleaning solution, taking into account the active ingredient content. Therefore, the carbon analysis will determine if the carbon loading is below or above this maximum limit.

[0060] Alternatively, the lipid substance (in an organic solvent that is immiscible with water in all proportions)
By extracting lipophilic substances), the proportion of total organic carbon present in the form of lipid substances (lipophilic substances) can also be determined. When the solvent is evaporated, lipid substances (
(Lipophilic substance) remains and can be analyzed by gravimetric methods. However, if preferred, the infrared absorption of lipid substances (lipophilic substances) in the extract can also be analyzed by photometric methods. In particular, halogenated hydrocarbons can be used as organic solvents that are immiscible with water in all proportions. A preferred example is 1,1,2-trichlorotrifluoroethane. This analysis method is based on DIN
38409, part 17, but in contrast to this method, the proportion of lipid substances (lipophilic substances) in the sample can be determined in the organic solvent without relying on gravimetric methods following evaporation of the organic solvent. Is analyzed by the photometric analytical method. Quantitative analysis, DIN
Preferably, the measurement is performed by measuring the infrared absorption of lipid substances (lipophilic substances) in the extract at the characteristic vibration frequency of the CH ₂ group, as specified in 38409, part 18. In this case, it is advantageous that the organic solvent used for the extraction does not itself contain a CH ₂ group. For example, an infrared absorption band at 3.42 μm (2924 cm ⁻¹ ) can be used for this photometric analysis. All organic substances that contain CH ₂ groups and can be extracted into organic solvents can be detected. Surfactants may also be present in the cleaning solution. If this surfactant is not detected, it can be measured independently by another method and subtracted from the overall result. If necessary, the partition coefficient of the surfactant between the cleaning solution and the organic solvent, which is immiscible with water in all proportions, must be determined in advance. However, in practice, it may be sufficient to further take into account the surfactant component and to fix the maximum allowable lipid substance (lipophilic substance) loading of the cleaning solution. If this maximum value is exceeded, bath treatment means (measurement) is started.

As part of this method, it is advantageous to calibrate the infrared spectrometer with a known amount of lipid substances (lipophilic substances). For example, 400-500 mg of methyl palmitate in 100 ml of 1,1,2-trichlorotrifluoroethane
Can be calibrated. This calibration solution can also be used to monitor the function of the IR photometer.

In this case, it is preferable to first add a phosphoric acid-magnesium sulfate solution to a sample of the cleaning solution. The solution is 85% by weight in deionized water.
It can be prepared by dissolving 125 ml of phosphoric acid and 220 g of crystalline magnesium sulfate, and adding deionized water to make up to 1000 g. The sample solution is mixed with about 20 ml of the phosphoric acid-magnesium sulfate solution. Thereafter, 50 ml of an organic solvent immiscible with water in all proportions, preferably 1,1,2-trichlorotrifluoroethane, are added. The aqueous and organic phases are mixed, causing phase separation and separating the organic phase. Preferably, the organic phase is further washed with a phosphoric acid-magnesium sulfate solution, causing a phase separation again, and separating the organic phase. This is transferred to a measurement cuvette, and infrared absorption is measured at a vibration frequency of a CH ₂ group. A suitable measuring cuvette is, for example, a quartz glass cuvette having a coating thickness of 1 mm. By comparing with the calibration curve, it also includes the blind value of the photometer and the lipid substances (lipophilic substances) in the sample based on infrared absorption
Can be measured.

In practicing the method of the present invention, it may be desirable to detect both inorganic carbon and total organic carbon (TOC). This is the case, for example, when burning a sample to analyze its carbon content. In this case, if CO ₂ is separated from the carbonate at the selected combustion temperature, carbon in the form of carbonate or dissolved CO ₂ is further detected. If no further inorganic carbon is measured in such a case, the sample can be acidified and the resulting CO ₂ can be removed by purging with a gas, for example air or nitrogen. This may be desirable in special cases, such as measuring only the "fat loading" of the cleaning bath. When the carbon content present in the form of lipophilic substances is analyzed by the extraction method described above, inorganic carbon is not automatically detected. Volatile organics can also be removed from the sample before sub-step (d) by purging with a gas, for example air or nitrogen. For example, volatile solvents are thus eliminated before carbon analysis.

Iii) Analysis of alkalinity The analysis of alkalinity can be carried out as described in German Patent Application DE 198 02 725.7. In sub-step (c), in particular in this method, a choice is made whether to analyze free alkalinity and / or total alkalinity. This can be incorporated into the program flow so that it does not change. For example, both free alkalinity and total alkalinity can be analyzed in an analysis cycle. However, the program may decide to analyze one of these two values more frequently than the other. That is, for example, the case where previous analysis indicates that one of the two values changes more rapidly than the other. Of course, the choice of whether to analyze free alkalinity or total alkalinity can also be made upon external request. An "external request" is to be understood as an intervention in an automated analysis process, performed manually by a data line or by a higher-level program control system.

The terms “free alkalinity” and “total alkalinity” are not necessarily clearly defined and are treated in various ways by each user. For example,
To analyze free or total alkalinity, a specific pH value must be titrated to that value, for example a value of pH 8 for free alkalinity and a value of pH 4.5 for total alkalinity. be able to. These preselected pH values need to be input to the control system for the automated analysis process. Instead of a specific pH value, a color change range of a specific indicator may be selected in order to define the free alkalinity and the total alkalinity. Alternatively, the inflection point of the pH curve can be selected and defined as the equivalent point for free alkalinity or total alkalinity.

The alkalinity is analyzed in sub-step (d) using an acid-base reaction with an acid. It is preferred to select a strong acid for this purpose. In this case, the sample can be titrated by adding the acid to a predetermined standard for free alkalinity or total alkalinity. Alternatively, one can start with the acid and titrate the acid with the sample. Various sensors are suitable for the subsequent acid-base reaction of the cleaning solution using the acid for titration. In the current state of the art, it is preferable to use a pH-sensitive electrode, for example a glass electrode. This gives a pH dependent voltage signal which can be further analyzed. The use of such electrodes is particularly simple with regard to the device and is therefore preferred.

However, following the acid-base reaction of sub-step (d), the pH due to electromagnetic radiation
Indicators that can measure dependent interactions can also be used. For example,
The indicator may be a typical indicator capable of photometrically measuring a color change. Alternatively, an optical sensor can be used. It consists, for example, of a film of an inorganic or organic polymer containing a fixed dye, which changes color at a specific pH. For a typical indicator, the color change is based on the principle that hydrogen ions or hydroxyl ions, which can diffuse into the film, react with the dye molecules. Changes in the optical properties of the film can be analyzed photometrically. Alternatively, films whose refractive index changes as a function of pH, for example organic polymers, can be used. For example, coating an optical conductor with such a polymer results in total internal reflection at one of the refractive index thresholds in the optical conductor, thus transmitting the light beam. However, if no other total reflection of the index threshold occurs, the light beam exits the optical conductor. At the end of the optical conductor, it can be detected whether light is transmitted through the optical conductor. Such a device is known as an "optrode".

Inorganic or organic solid substances whose electrical properties change with the pH of the surrounding solution can also be used as sensors. For example, ionic conductors whose conductivity is a function of the concentration of H + or OH- ions can be used. By measuring the DC or AC conductivity of the sensor, the pH of the surrounding medium can also be estimated.

Calibration / Control Measurements The method of the present invention is such that the measurement device used for each analysis can be self-monitored and, if necessary, can be self-calibrated. For this purpose, after a predetermined time interval or after a predetermined number of analyses or according to external requirements, by means of controlled measurements using one or more standard solutions, the functionalities of the measuring device used are It can also be provided so that characteristics can be checked. Standard solutions with known values of the parameters to be analyzed are measured for checking purposes. This check is most practical when a standard cleaning solution having a composition as close as possible to the composition of the cleaning solution to be checked is used as the standard solution.

If, during the control measurement of the standard solution, the measuring device measures a value which deviates from the reference content by a predetermined minimum amount, the measuring device issues an alarm signal locally or preferably at a remote location. In this case, the alarm signal may include an intervention proposal selected by the control program of the measuring device or by a higher-level process control system.

An important feature of checking the functional properties of an alkalinity measuring device involves monitoring the sensors used. For example, this sensor has p
H-sensitive electrodes, especially glass electrodes, are included. If a buffer solution is used as a standard solution, the electrode produces a predetermined voltage, that voltage corresponds to a predetermined time interval, and its gradient (= voltage change as a function of pH change) It can be checked whether it is within a desired range. Otherwise, the measurement device issues an alarm signal locally or, preferably, at a remote location. In this case, the alarm signal may include an intervention proposed by the control program of the measuring device or by a higher-level process control system. For example, suggestions may include cleaning or replacing the electrodes.

According to the method of the present invention, when two consecutive measurements differ to a certain extent,
One or more standard solutions can be set up to check the functional properties of the measuring device used. In this way, a set deviation in the contents of the cleaning solution actually occurs, identifying whether bath treatment means (bath measurement) are required or whether they resemble defects in the measurement system. be able to.

According to the result of the check of the measuring device to be used, the analysis performed between the previously performed control measurement and the current control measurement should be accompanied by a state characteristic display indicating the reliability of these analysis. Can be. For example, if a continuous control measurement to check the used measuring device indicates that it is operating properly, the analysis is given a state characteristic of "OK". If the results of the control measurements differ by a predetermined degree to a certain degree, an intervention analysis is prepared, for example, with a "doubtful" state characteristic.

Depending on the result of checking the measuring device used, the automatic analysis of the variables to be measured is continued and / or one or more of the following actions are performed: analysis of the determined deviation, Correction, termination of the analysis of the relevant measured variables, transmission of alarm signals or status notifications to higher-level process control systems or monitoring devices and thus to remote locations. If desired, the measurement device can itself determine whether it is sufficient to function to allow all analysis to proceed or whether a deviation requiring manual intervention is identified. .

The measurement system used in the method of the present invention automatically monitors the consumption and / or level of the solvent and reagent used and the flushing solution and issues an alarm signal if below a predetermined minimum level. Is preferred. In this way, it is possible to prevent the measurement device from becoming inoperable due to a shortage of necessary chemicals. Monitoring the level is performed according to known methods. For example, a vessel containing a chemical may be placed on a scale that records the specific weight of the chemical. Alternatively, a float can be provided. Alternatively, the minimum level can be checked by a conductive electrode immersed in a vessel containing the chemical. Preferably, the alarm signal from the measuring device is transmitted to a remote location, and an appropriate measurement is started from the remote location. Generally, in the method of the present invention, the results of the analysis and / or the results of the control measurements and / or the results of the calibration and / or the status signals are continuously or at predetermined time intervals and / or on demand. And sent to a remote location. In this way, the measurer can always receive information about the current alkalinity content of the bath without having to be at the point of the cleaning bath. Depending on the results of the control measurements and analysis, measurements for the necessary corrections are made either automatically through the process control system or by manual intervention.

As part of the method of the present invention, each analysis selected from analysis (i), (ii) and (iii) may be performed after a predetermined time interval or after a predetermined number of analyses. Check the functional properties of the measuring device to be used by controlled measurement of one or more standard solutions and send the result of the check to a remote location at or on request from a remote location It is. Furthermore, a corresponding check of the functional properties of the measuring device used can be started when two consecutive measurements differ to a certain extent. The result of this check is also preferably sent to a remote location. Depending on the results of the check on the measuring device used, the analysis of the corresponding measurement variables performed between the previous control measurement and the current control measurement will give a state characteristic indication of the reliability of these analyses. It can also be attached.

In the method according to the invention, depending on the result of one or more assays selected from assays (i), (ii) and (iii), an additional supply of supplementary components and / or one or more additional components May be provided so as to start from a remote place. Alternatively or additionally, depending on the result of one or more assays selected from assays (i), (ii) and (iii), an additional supply of supplemental components and / or one or more additional components Can be provided to start the bath treatment means in a program controlled manner.

Further, in the method of the present invention, when a predetermined relationship is confirmed between the results of at least two analyzes selected from the assays (i), (ii) and (iii), the supplementary component is additionally added. The supply and / or one or more bath treatment means can also be provided to start in a programmed manner. Therefore, a specific relationship between the results of the individual analyzes (i), (ii) and (iii) is preset in the control program for the process, and when such a relationship occurs, the replacement of supplementary components Additional feeding and / or bathing means are started. Decisions in this regard are not made based on one independently measured value, but rather by measuring at least two values from various bath parameters. In this case, the relationship at the start of the measurement can be changed from a remote location, for example, to take into account the driving history. For example, if the total organic carbon is above a predetermined maximum content on the one hand and the surfactant content is below a predetermined minimum value on the other hand, means for reducing the fat loading of the cleaning bath (whole or part of the bath). And / or fat from the bath by the method of renewal, separation and / or membrane filtration
Or oil removal). Alternatively, a certain maximum value is given to the sum of the surfactant content and the fat loading, in particular, the bath treatment means is started automatically. Depending on the determined changes in the measured values or the measured values obtained, measurements for one or more of the following corrections are initiated.

Modification and Bath Treatment Means The simplest modification means is to activate the device when one or more of the specified maximums of inorganic carbon and / or total organic carbon is exceeded or in response to external requests. Further replenishment components (solutions or powders) are fed into the cleaning bath.
This can be done in an automated manner, for example, by feeding a specific amount of replenisher solution or powder into the cleaning bath based on the measured carbon content. In this case, the size of the portion to be added itself, or in the case of a fixed amount of addition, the time interval between individual additions can be varied. The supply can be effected, for example, by a supply pump or by weight control. In the method of the invention, on the other hand, if there is a certain deviation from the standard value (especially if the functional properties of the measuring device have been confirmed by control measurements), a certain amount of replenisher component is introduced into the cleaning bath. Is further supplied. Furthermore, it is provided that a bath replenishment measure is implemented when a predetermined minimum change in the carbon content has been determined. However, furthermore, this additional supply can also take place externally, for example from a remote location, independent of the current carbon content. For example, the additional supply of surfactant increases the carbon content of the cleaning bath. Based on the following analysis of carbon content,
This has to be taken into account in an appropriate manner and it is done automatically. The addition of the surfactant increases the oil and fat (oil and fat) content of the cleaning bath. Therefore, it is necessary to raise the maximum allowable carbon loading, above which the next bath treatment is started. This is provided automatically in the control program.

Instead of an additional supply of bath components, such as surfactants, or above a predetermined maximum content of inorganic carbon and / or total organic carbon, the inorganic carbon and / or total organic carbon content in the cleaning bath The bath treatment means can be started in order to reduce the temperature. Such bath treatment means are specifically aimed at reducing the fat and oil content of the cleaning bath. In the simplest case, this is done by draining the cleaning solution, wholly or partially, and replacing it with a fresh cleaning solution. However, it is more economical to separate the grease component from the cleaning solution by means known in the prior art, such as separation by a separation device or by membrane filtration. In these methods, the surfactant is at least partially discharged as well, so that the cleaning solution must be properly replenished. Initiation of these measures may not only depend on the pure carbon content of the cleaning solution, but also on certain changes in the carbon content.

For monitoring and control of surfactant content and / or alkalinity, the device may be activated by one or more by exceeding a predetermined minimum value of the content or based on external requirements. Is supplied into the cleaning bath. For example, a replenishment solution containing the active component of the cleaning solution in an appropriate ratio can be used as the replenishment component. Thus, the replenishment solution can contain not only the monitored components, but also other active components of the cleaning solution, such as surfactants, builder substances, alkalis, complexing agents and corrosion inhibitors. In another embodiment, the replenishment solution contains only surfactants or only alkalis, while other components of the cleaning solution are analyzed independently in a time-controlled or throughput-controlled manner. , And can be further supplied.

In this case, the size of the added portion itself or, if the added portion is fixed, the time interval between individual additions can be changed. The supply can be effected, for example, by a supply pump or by weight control. In the method of the invention, on the other hand, if there is a certain deviation from the standard value (especially if the functional properties of the measuring device have been confirmed by control measurements), a certain amount of replenisher component is introduced into the cleaning bath. Is further supplied. On the other hand, this additional feed can also take place, for example from a remote location, according to external requirements, independent of the surfactant and / or alkali content at the time. In another aspect of the invention, the processing solution is replenished in a throughput dependent manner using a predetermined amount of replenisher per unit throughput. For example, in the case of a cleaning bath for a car body, the amount of supplemental component added for each cleaned body can be specified. According to the present invention, the monitoring of surfactant content and alkalinity, then, depends on the result-dependent precise addition, and in some cases by interrupting the basic feed, to make this preset addition successful. It contributes to monitoring and recording and can achieve a more stationary mode of operation of the cleaning bath.

Of course, the method of the present invention requires the use of the appropriate device. This includes a control unit, for example a computer control unit,
This controls the measurement process in a time and / or event dependent manner. It is also necessary to include the reagent vessels, pipelines, valves, supply and metering devices, etc. necessary to control and measure the sample flow. These materials include:
For example, those made of high-quality steel and / or plastic can be used according to the intended use. The control electronics of the measuring device have suitable input-output interfaces so that communication with remote points can be made.

The method of the present invention, on the other hand, allows the contents of the cleaning bath to be checked on site and to initiate certain appropriate measures without manual intervention. In this way,
The reliability of the method is improved and a steady and reliable cleaning result is obtained. Deviations from the standard values can be detected early in time and corrected automatically or manually before the cleaning results are compromised. On the other hand, it is preferable to send the measurement results to a remote location and the operator or supervisor should be constantly informed about the condition of the cleaning bath, even if they are not in close proximity to the bath. Can be. Thus, the costs associated with personnel monitoring and controlling the cleaning bath can be substantially reduced. The documentation of the data obtained by the method of the invention corresponds to today's quality assurance requirements. Chemical consumption is recorded and optimized.

──────────────────────────────────────────────────の Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), AU, BG, BR, BY, CA, CN, CZ, GE, HR, HU, ID, IN, IS, JP, KG, KP, KR, KZ, LK, LT, LV, MD, MX, NO , NZ, PL, RO, RU, SG, SI, SK, TJ, TM, TR, UA, US, UZ, VN, YU, ZA (72) Inventor Wolfgang Clay Day 42113 Wuppertal, Germany Morspfat No. 17 (72) Inventor Werner Opitz Germany Day-40664 Langenfeld, Wi Neburgstrasse No. 67 (72) Inventor Roots Husemann D-42781 Hahn, Zanddornweg 7 (72) Inventor Bernd Schönzl D-40699 Erkrath, Sylchmar Wöck 21 (72) Inventor Peter Combe, Federal Republic of Germany-40724 Hilden, Clarenbachweg No. 3 (72) Inventor Detlef Bornhorst Federal Republic of Germany, Day-51429 Arnulf Villars Federal Republic of Germany Day 51503 Läsler, Auf Dem Knippen No. 6 (72) Inventor Herbert Puderbach Federal Republic of Germany Day 40724 Hilden, Clarenbachweg No. 3 (72) Inventor Hans-Willi・ Kling Germany Day-42277 Wupperta , Königsberger Straße 76th day (72) Inventor Reiner Moll Germany Day-41439 Dolmagen, Am Ringenaker 12th F term (reference) 2G052 AA11 AB05 AB06 AB12 AC16 AD42 HC39 HC43 HC44 JA06 JA20 4K053 PA02 QA04 QA05 QA06 RA07 RA21 RA64 YA05 YA17

Claims (17)

[Claims] 1. A method for monitoring a cleaning bath, comprising: (i) analysis of surfactant content, (ii) analysis of inorganic carbon and / or total organic carbon loading, and (iii) analysis of alkalinity. Performing the two analyzes in a programmatically controlled manner; and (a) starting an additional supply of supplemental components and / or one or more bath treatment means based on the results of the analysis; And / or (b) sending the results of the analysis and / or data derived from the results of the analysis to at least one remote location located at a location different from the device for performing the analysis. 2. The method according to claim 1, wherein the remote location is at least five (5) minutes from an apparatus for performing the analysis.
2. The method according to claim 1, wherein the method is arranged at intervals of 00 m. 3. When a new analysis result and / or data derived from the analysis result is determined, the analysis result and / or the data derived from the analysis result are automatically transmitted to a remote location. 3. The method according to claim 1, wherein the method comprises: 4. The method according to claim 1, wherein the result of the analysis and / or the data derived from the result of the analysis is transmitted to a remote location in response to a request from a remote location. 5. The method according to claim 1, wherein the individual analyzes are repeated at predetermined time intervals. 6. The method according to claim 1, wherein the individual analyzes are repeated at shorter time intervals when the difference between the results of two consecutive analyzes is greater. Method. 7. The method according to claim 1, wherein the analysis is performed in response to a request from a remote place. 8. The method according to claim 1, wherein the first analysis selected from the analysis (i), (ii), and (iii) results in exceeding a predetermined maximum value, lowering a predetermined minimum value, or immediately before the first analysis. Analysis results that deviate from the results by a predetermined minimum.
The method according to any one of claims 1 to 4, wherein the second analysis selected from (i), (ii) and (iii) is performed in a program-controlled manner. 9. (i) in a program-controlled manner: (a) taking a predetermined amount of sample from the treated aqueous solution; (b) separating solid material from the sample, if desired; c) if desired, diluting the sample with water to a preset ratio or a ratio determined by the results of a preliminary analysis; and (d) analyzing the surfactant content by selective adsorption, electrolysis, Separation and stripping of volatile compounds by chemical methods, chromatographic methods, and detection of volatile compounds, or the interaction of a sample with electromagnetic radiation in proportion to the surfactant content 9. A method according to any of claims 1 to 8, wherein the analysis of the surfactant content is carried out by making a change and measuring the change in this interaction. 10. (ii) in a program-controlled manner: (a) taking a predetermined amount of sample from the cleaning aqueous solution; (b) if desired, separating solid material from the sample; And / or homogenizing the solid material; (c), if desired, diluting the sample with water to a predetermined ratio or a ratio determined by the results of a preliminary analysis; and (d) a known method. The analysis of the loading of inorganic carbon and / or total organic carbon is performed by analyzing the content of inorganic carbon and / or total organic carbon in a sample by using the method. the method of. (Iii) in a program-controlled manner: (a) taking a predetermined amount of sample from the cleaning bath; (b) separating solid material from the sample, if desired; (C) choosing whether free alkalinity and / or total alkalinity should be analyzed; and (d) titrating the sample by adding an acid, or using an acid as a starting material, depending on the sample. The method according to any one of claims 1 to 8, wherein the alkalinity of the cleaning bath is analyzed by an acid-base reaction using an acid by titration. 12. For each analysis selected from analysis (i), (ii) and (iii),
At predetermined time intervals, or after a predetermined number of analyses, or on demand from a remote location, the functional characteristics of the measuring device used by the control means of one or more standard solutions are determined. The method according to any of the preceding claims, wherein the method checks and sends the result of the check to a remote location. 13. For each analysis selected from analysis (i), (ii) and (iii),
If the results of two consecutive analyses differ to a certain extent, one or more standard solutions are used to check the functional properties of the measuring device used and to send the results of the check to a remote location A method according to any of the preceding claims, characterized in that: 14. The method according to claim 1, wherein the analysis performed between the current time and the previous control measurement is accompanied by a state characteristic indication indicating the reliability of the analysis, based on the result of the check of the measuring device used. Item 14. The method according to Item 12 or 13. 15. Depending on the result of one or more analyzes selected from analyzes (i), (ii) and (iii), additional supply of supplementary components and / or one or more bath treatment means may be provided. The method according to any of the preceding claims, wherein the method is started from a remote location. 16. Depending on the result of one or more analyzes selected from analyzes (i), (ii) and (iii), additional supply of supplementary components and / or one or more bath treatment means may be provided. Starting in a program controlled manner.
15. The method according to any of 14. 17. When a predetermined relationship is confirmed between the results of at least two analyzes selected from assays (i), (ii) and (iii), additional supply of supplemental components and / or
15. A method according to any of the preceding claims, characterized in that one or more bath treatment means are started in a program-controlled manner.