JPH06341968A - Monitoring device for deterioration of aqueous cleaning liquid - Google Patents

Abstract

PURPOSE:To automatically and continuously measure both alkaline concentration and oil content concentration in a cleaning liquid at the same time by separating oil through a frequency generator, and measuring the conductivity of aqueous cleaning liquid. CONSTITUTION:Whole of parts are automatically actuated by the signal of a controller 1 to discharge sensor-stabilizing pure water in an oil and water separating vessel 16 to a waste liquid storing vessel 17, and liquid in a cleaning liquid introducing pipe 13 and the vessel 16 is replaced with an aqueous cleaning liquid. Substituted liquid is returned to a cleaning vessel, and the cleaning liquid is resupplied 14 to the vessel 16, and the conductivity of the liquid detected by a conductivity measuring sensor 6 for the mixed concentration of alkaline and oil contents is measured by an electric conductivity meter 2. Next, a special frequency generator 3 is actuated to vibrate oil particles at a frequency having generated 15 voltage, and the double interface 2 layer of the surface of the oil particle is thereby destroyed to lower zeta potential. The particles concentratingly grow to float on a liquid surface, and their oil content become less than 10% to show alkali concentration. This concentration is detected 6 to measure 2 conductivity. The two measured conductivities are converted into the alkali and oil content concentrations by the computing device of the controller 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based cleaning liquid deterioration monitoring device attached to a water-based cleaning machine to monitor the deterioration condition of the water-based cleaning liquid.

[0002]

2. Description of the Related Art Conventionally, in order to keep economical detergency constant, water-based washing machines and the like measure free alkalinity and total alkalinity by means of chemical analysis and maintain them. If a large amount of unsaponifiable matter (for example, mineral oil) is mixed in even if the cleaning solution is excellent even if it is a specified value, even if the alkali concentration is a specified concentration, the mixed oil interferes and complete degreasing is performed. In this case, the cleaning liquid has reached the limit of use and has deteriorated.

In order to manage this, it is not sufficient to measure and manage only the free alkalinity and the total alkalinity, and it is necessary to measure the alkali concentration together with the oil concentration and judge and maintain the result based on both results. By the way, the free alkalinity and the total alkalinity are measured by measuring the alkaline components such as silicate, caustic soda and phosphate in the detergent, and the oil content cannot be measured.

At present, there are the following methods for measuring oil content in an aqueous cleaning liquid, and all of them are carried out by manual analysis. (Salting out method) 200 ml of the washing liquid is taken in 250 ml of a graduated cylinder, sodium chloride is added until the liquid reaches 250 ml, and the graduated cylinder is turned over to dissolve the sodium chloride. At this time, unsolvable sodium chloride is generated due to supersaturation. The graduated cylinder is left standing for 24 hours, and the separated oil content and the precipitated insoluble content are measured. Generally, when the separated oil content and the precipitated insoluble content exceed 10% in total, it is judged that the cleaning liquid has deteriorated, and it is used as a guide for the renewal time of the liquid.

(Solvent extraction method) The cleaning liquid is extracted with a solvent such as n-hexane or carbon tetrachloride, and the residue after the extraction solvent is distilled is measured. However, these methods have the following problems. (a) Since it takes a long time to carry out the measurement, the measurement tends to be misdirected, and the cleaning liquid is insufficiently monitored.
(b) In manual analysis, there are cases where the operation of extracting the oil component in the cleaning liquid into the solvent is insufficient, and the measured values may vary.

On the other hand, as the automatic concentration measuring device, there are a component concentration measuring device (see JP-A-4-286948) and an alcohol concentration detecting method (see JP-A-63-150655). Since the measurement is performed at high frequency and dual wavelength, the device is complicated, and it is impossible to measure the alkali concentration and the oil concentration in the aqueous cleaning liquid by these methods.

For oil-water separation by the AC voltage method, an electric oil-water separator (see Japanese Patent Laid-Open No. 54-54973),
There are a liquid electrical treatment method (see JP-A-60-6016), a two-liquid separation method and an apparatus therefor (see JP-A-3-77603), and the like. There are no examples of measuring alkali concentration and oil concentration.

[0008]

By the way, in order to monitor the deterioration of the water-based cleaning liquid, it is necessary to continuously and automatically simultaneously measure the alkali concentration and the oil content concentration in the cleaning liquid.
As is well known, there are (a) infrared absorption characteristics around 3 μm based on C—H bond, (b) oil and water emulsification characteristics, and (c) ultraviolet absorption characteristics for automatic measuring devices for oil concentration in wastewater. ,
(d) Although a measuring device has been devised for measuring substances that emit fluorescence when irradiated with ultraviolet rays, there is no water-based cleaning liquid deterioration monitoring device that automatically simultaneously measures the alkali concentration and oil content concentration in the water-based cleaning liquid.

The present invention has been made in consideration of such circumstances. Since the alkali concentration and the oil concentration in the aqueous cleaning liquid cannot be measured by the low frequency and high frequency dual wavelength measuring methods, a frequency oscillator is used. By separating the oil and measuring the conductivity of the water-based cleaning liquid with a conductivity meter, it is an object to provide a water-based cleaning liquid deterioration monitoring device capable of continuously and automatically measuring the alkali concentration and the oil concentration in the water-based cleaning liquid at the same time. To do.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a monitoring device attached to a water-based cleaning machine to monitor the deterioration status of a water-based cleaning liquid, a controller, a frequency oscillator electrically connected to the controller, and an electrode. A plate, an electric conductivity meter electrically connected to the controller, an arithmetic unit provided in the controller, an oil / water separation container, a pure water storage container, a water-based cleaning machine, and a water-based cleaning machine Supply means for supplying a fixed amount of the cleaning liquid from the cleaning tank to the oil-water separation container, a separation means for separating the liquid in the oil-water separation container into oil-water, and the conductivity of the liquid separated in the oil-water separation container is measured. Supply means for converting the electric conductivity into a concentration, a discharging means for discharging the liquid in the oil / water separation container, and a constant amount of pure water in the pure water storage container for supplying to the oil / water separation container. And the pure water in the oil / water separation container is stirred. Is an aqueous cleaning liquid deterioration monitoring apparatus characterized by comprising a stirring means for.

[0011]

In the present invention, all the members are automatically turned ON-OF at regular time intervals by the signal sent from the controller.
It operates like F. Therefore, supply a fixed amount of cleaning liquid and pure water to the oil / water separation container, oil separation by a frequency oscillator in the oil / water separation container, measurement of conductivity, conversion of conductivity to alkali concentration and oil concentration, printing of data, alarm It is possible to automatically operate an alarm device consisting of sounds and alarm lamps, discharge waste liquid, and clean the oil / water separation electrode plate / conductivity sensor and oil / water separation container with pure water.

In the present invention, in order to continuously and automatically measure the alkali concentration and the oil concentration in the aqueous cleaning liquid, the alkaline concentration of the cleaning liquid used in advance is set to 2, 4, 6, 8, 10 (Vol.
%), And the oil content to be degreased for each concentration is added with 2, 4, 6, 8, 10 (Vol%) to prepare a mixed standard solution of alkali and oil. The conductivity of this mixed standard solution is measured to determine the relationship between the alkali concentration and the oil content concentration. This relation is stored in an arithmetic unit (not shown) in the controller, and the dielectric constants of the actual alkali concentration and oil concentration of the cleaning liquid are converted into concentrations. This will be described in more detail with reference to FIG. FIG. 2 is a characteristic diagram showing the relationship between the alkali concentration and the oil concentration of the cleaning liquid in order to easily understand the measurement of the present invention. FIG. 3 is a characteristic diagram showing the relationship between the alkali concentration and the oil content concentration of an aqueous cleaning liquid that is actually used.

The measuring method of the monitoring device according to the present invention will be described below with reference to FIG. First, the conductivity δ ₁ of a cleaning liquid in which a detergent having an alkali concentration and a washed oil component are mixed is measured. This is 1 mS (microsiemens). At this time, it is necessary that the separation ratio of the alkali component and the oil component is 90% or more. Next, the cleaning liquid is separated from oil by a frequency oscillator, left for a certain period of time, and then once again the conductivity δ
Measure ₂ . This is set to 3 mS. Since 90% or more of the oil content was removed from the measured value of δ ₂ , the conductivity of the oil content hardly contributes, and if any of the conductivity values of the alkali concentration alone is applicable, the corresponding concentration is the alkali of the cleaning liquid. Indicates the concentration (3 Vol%). The oil concentration is indicated by the point that intersects with the conductivity of δ ₁ (1 mS) along the diagram for obtaining the alkali concentration in the previous period, and the oil concentration (4 Vol
%) Can be obtained from the horizontal axis. All of these are density-converted from the relationship stored in an arithmetic unit (not shown) in the controller, and displayed on the printer as density.

By the way, in order to measure the alkali concentration and the oil concentration, it is necessary to separate the cleaning liquid into the alkali component and the oil component, and it depends largely on the frequency oscillator. The operation is as follows. Generally, when oil is mixed in an aqueous solution, most of it floats as an oil phase on the liquid surface, but at a water-based washing station in which a surfactant is mixed, it is emulsified and a minute amount of water is contained in the liquid. Floats as oil particles. The floating oil droplets form an interfacial double layer on the surface and carry a charge called zeta potential. In a normal state, due to Coulomb (repulsive force) due to this electric charge, the small oil droplets are stably suspended in the aqueous solution, and it is difficult to separate them without floating on the interface.

The frequency oscillator is for applying an AC voltage having a predetermined frequency of 4 V to 10 V to the electrode plate in the oil / water separation container, and the oil particles vibrate according to the frequency of the applied voltage.
Due to the vibration of the potential from the outside and the vibration of the surface portion of the particle, the interface double layer on the oil particle surface is destroyed and the zeta potential is lowered. That is, the repulsive force is reduced, the oil particles attract each other and aggregate to grow into large oil droplets, and the oil particles float on the liquid surface by their own buoyancy, so that the amount of oil in the cleaning liquid is 90%.
% To 95% is removed, and the cleaning liquid becomes almost alkaline.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. Reference numeral 1 in the figure is a controller having an arithmetic unit (not shown) inside. An electric conductivity meter 2 and a special frequency oscillator 3 are electrically connected to the controller 1, respectively. The electric conductivity meter 2 includes a printing device 4 and an alarm device 5.
And the sensor 6 are electrically connected. Further, in the controller 1, a waste liquid electromagnetic valve 8 attached to a waste liquid discharge pipe 7, a pure water pump 10 attached to a pure water supply pipe 9,
A stirrer 11, a liquid replacement solenoid valve 12 attached to the waste liquid discharge pipe 7, and a water-based cleaning liquid supply metering pump 14 attached to the cleaning liquid introduction pipe 13 are electrically connected to each other. The sensor 6 is arranged in an oil / water separation container 16 together with an oil / water separation electrode plate 15. A waste liquid storage container 17 is connected to the oil / water separation container 16 via a waste liquid discharge pipe 7 on the side where the waste liquid electromagnetic valve 8 is interposed. Pure water supply pipe 9
A pure water storage container 18 is communicated with the. In the figure, reference numeral 19 is a cleaning liquid overflow container, reference numeral 20 is a cleaning liquid overflow pipe communicating with the cleaning liquid overflow container 19, and reference numeral 21 is a rotor mounted on the stirring device 11.

The measurement of the alkali concentration and the oil concentration of the water-based cleaning liquid by the monitoring device having the above structure is performed as follows. When the power of the controller 1 is turned on, the electric conductivity meter 2 and the printer 4 are powered on and stabilized. Prior to measuring the alkali concentration and the oil concentration, the waste liquid solenoid valve 8 is activated by a signal from the controller 1, and the sensor stabilizing pure water in the oil / water separation container 16 passes through the waste liquid discharge pipe 7 to form a waste liquid storage container. 17
Is discharged to. The metering pump 14 for supplying the cleaning liquid is operated by a signal from the controller 1, and the cleaning liquid in the cleaning tank (not shown) of the water-based cleaning device passes through the cleaning liquid introducing pipe 13 to separate the oil-water separation container
16 and the inside of the cleaning liquid introducing pipe 13 are replaced with liquid. The liquid replacement solenoid valve 12 is activated by a signal from the controller 1, and the liquid replaced liquid is returned to the cleaning tank (not shown) of the water cleaning machine through the waste liquid discharge pipe 7.

The metering pump 14 for supplying the cleaning liquid is activated again by a signal from the controller 1, and the cleaning liquid in the cleaning tank (not shown) of the water-based cleaning device passes through the cleaning liquid introducing pipe 13 to separate the oil-water separation container.
Supplied to 16. The electric conductivity meter 2 and the conductivity measuring sensor 6 are activated by a signal from the controller 1, and the conductivity of the mixed concentration of the alkali component and the oil component detected by the conductivity measuring sensor 6 inserted in the cleaning liquid. Is measured by the electric conductivity meter 2 and stored in an arithmetic unit (not shown) in the controller 1.

Next, the special frequency oscillator 3 is activated by the signal from the controller 1 to generate a potential on the oil / water separation electrode plate 15. The cleaning liquid vibrates the oil particles according to the frequency of the potential generated on the oil / water separation electrode plate 15, destroys the interface double layer on the particle surface, and lowers the zeta potential. Then, the particles agglomerate and grow, and float on the liquid surface with self-confident buoyancy, and the amount of oil in the cleaning liquid becomes 10% or less, indicating an alkali concentration. After a certain period of time, the electric conductivity meter 2 and the conductivity measuring sensor 6 are activated again by the signal from the controller 1, and the electric conductivity of the alkali concentration is measured by the conductivity measuring sensor 6 inserted in the cleaning liquid. It is measured by the gyro 2 and stored in an arithmetic unit (not shown) in the controller 1. The two electric conductivities stored in the arithmetic unit (not shown) in the controller 1 are converted into an alkali concentration and an oil concentration by a signal from the controller 1, and the alkali concentration and the oil concentration are respectively transferred to the printer 4. Printed.

When the printing of the printer 4 is stopped by the signal from the controller 1, the solenoid valve 8 for waste liquid is operated by the signal from the controller 1, and the measured cleaning liquid in the oil / water separation container 16 is discharged to the drain pipe for waste liquid. It flows down through 7 and is discharged to a waste liquid storage container 17. The pure water pump 10 is activated by the signal from the controller 1,
A certain amount of pure water is supplied from the pure water storage container 18 to the oil / water separation container 16 through the pure water supply pipe 9. The stirrer 11 is activated by the signal from the controller 1, and the rotor 21 stirs pure water to stir and wash the surface of the oil / water separation electrode plate 15, the conductivity measuring sensor 6 and the inner wall of the oil / water separation container 16. . When the stirring is stopped by the signal from the controller 1, the electromagnetic valve 8 for waste liquid is activated,
The cleaning liquid that has been measured in the oil / water separation container 16 is the waste liquid discharge pipe 7
And is discharged to the waste liquid storage container 17. The cleaning and the replacement of the aqueous cleaning solution can be set by the controller 1 so that the cleaning can be automatically repeated any number of times. When the waste liquid solenoid valve 8 is stopped by the signal from the controller 1, the pure water supply metering pump 10 is operated and pure water is stored in the oil / water separation container 16.
The pure water supply metering pump 10 is stopped by a signal from the controller 1. The stored pure water has a function of stabilizing the conductivity measuring sensor 6. Further, it prevents the dirt from adhering to the oil / water separation electrode 15. This operation returns the device to the initial state. When the alkali concentration and the oil concentration measured by the electric conductivity meter 2 reach the preset deterioration concentration range, the alarm device 5 including an alarm sound and an alarm lamp is activated to notify the deterioration.

The electric conductivity meter 2 in this apparatus has a structure in which one kind is selected from the mixed standard solution of alkali content and oil content, the conductivity of alkali content and oil content is measured as described above, and the controller 1 calculates in advance. The alkali concentration and the oil concentration are calculated from the relationship stored in the device (not shown). When the respective concentrations are not within ± 5% of the standard solution, a mixed standard solution is prepared again and the arithmetic unit of the controller 1 ( (Not shown).

In the monitoring device of the present invention, it is premised that 100% oil is separated so as not to be affected by the determination of the alkali concentration, but as a result of actually separating with a frequency oscillator, the following "Table 1" is obtained. As shown, the separation was not 100% but 90% to 95%. As a result, the alkaline concentration shows a low value with a variation of around 10% with respect to the mixed standard solution, but the alkaline concentration in a normal cleaning device is constantly fluctuating, and a difference of approximately 10% is entirely in control of the cleaning liquid. It doesn't matter.

[0023]

[Table 1]

It should be noted that, when measuring the present apparatus, it is impossible to measure the alkali concentration and the oil content concentration of the cleaning liquid when cleaning the oil containing the alkaline agent such as the water-soluble cutting oil. This is because the conductivity tends to increase as the amount of oil in the cleaning liquid increases as shown in FIG. 4, and does not decrease as shown in FIGS. 2 and 3. This is because the conductivity of the alkali concentration in which the cutting oil is dissolved contributes more than the conductivity of the oil concentration, and even if this oil is separated by the frequency oscillator, the alkali concentration in which the cutting oil is dissolved This is because it does not indicate Further, the intersection point as shown in FIG. 2 is not determined due to the influence of the alkali concentration to which the oil content concentration is added, and the oil content concentration cannot be obtained.

Next, it should be noted that a liquid obtained by washing oil containing amine such as rust preventive oil was separated by a frequency oscillator, but only 50% could be obtained under the separation conditions of "Table 1". It is necessary to separate under the separation conditions shown in "Table 2."

[0026]

[Table 2]

As described above, the above-mentioned water-based cleaning liquid deterioration monitoring device has the controller 1 and the controller 1 as shown in FIG.
A special frequency oscillator 3 electrically connected to the controller 1, an oil / water separation electrode plate 15, an electric conductivity meter 2 electrically connected to the controller 1, and an arithmetic unit provided in the controller 1. An oil / water separation container 16, a pure water storage container 18, a supply means for supplying a predetermined amount of cleaning liquid from the cleaning tank of the water-based cleaning machine to the oil / water separation container 16, and a liquid in the oil / water separation container for oil / water separation. Separation means, measuring means for measuring the conductivity of the liquid separated in the oil / water separation container 16, conversion means for converting the conductivity into concentration, and discharge means for discharging the liquid in the oil / water separation container 16. A supply means for supplying a fixed amount of pure water in the pure water storage container 18 to the oil / water separation container 16, and the oil / water separation container
It is configured to include a stirrer 11 having a rotor 21 that stirs the pure water inside 16. Therefore, according to the present invention, it is possible to automatically continuously measure the alkali concentration and the oil concentration of the cleaning liquid used in the water-based washing machine and the like, and the operator does not have to worry about the measurement, and the measurement of the alkali concentration and the oil concentration is possible. There is no variation in value. As a result, it is possible to reliably monitor the deterioration of the water-based cleaning liquid, reduce the consumption of the cleaning liquid while prolonging the life of the device and preventing adverse effects such as reverse contamination of the work (work) to be cleaned. it can. Further, the device of the present invention can be used alone in a laboratory or the like.

[0028]

As described above in detail, according to the present invention,
Since the low-frequency and high-frequency dual-wavelength measurement methods cannot measure the alkali concentration and oil concentration in the water-based cleaning solution, the frequency oscillator is used to separate the oil and the conductivity meter measures the conductivity of the water-based cleaning solution. Thus, it is possible to provide a water-based cleaning liquid deterioration monitoring device capable of continuously and automatically measuring the alkali concentration and the oil content concentration in the water-based cleaning liquid.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a water-based cleaning liquid deterioration monitoring device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between an alkali concentration and an oil concentration of a cleaning liquid related to the monitoring device of FIG.

FIG. 3 is a characteristic diagram showing the relationship between the alkali concentration and the water-insoluble oil concentration of an aqueous cleaning solution that is actually used.

FIG. 4 is a characteristic diagram showing a relationship between an alkali concentration and a water-soluble oil content concentration when water-soluble cutting oil is washed with an aqueous cleaning liquid.

[Explanation of symbols]

1 ... Controller, 2 ... Electrical conductivity meter, 3 ... Special frequency oscillator, 4 ... Printer, 5 ... Alarm device,
6 ... Sensor for measuring conductivity, 7 ... Discharge pipe for waste liquid,
8 ... solenoid valve for waste liquid, 9 ... pure water supply pipe, 10 ... pure water pump, 11 ... stirring device, 12 ... solenoid valve for liquid replacement,
13 ... Cleaning liquid introduction pipe, 14 ... Metering pump, 15 ... Pure water separation electrode plate, 16 ... Oil water separation container, 17 ... Waste liquid storage container, 18 ... Pure water storage container, 19 ... Cleaning liquid overflow container, 21 ... Rotor.

Claims (1)

[Claims] 1. A monitoring device attached to a water-based cleaning machine for monitoring deterioration of a water-based cleaning liquid, a controller, a frequency oscillator electrically connected to the controller, an electrode plate,
An electric conductivity meter electrically connected to the controller, an arithmetic unit provided in the controller, an oil / water separation container, a pure water storage container, a water cleaning machine, and a cleaning tank of the water cleaning machine. Supply means for supplying a predetermined amount of cleaning liquid to the oil-water separation container, separation means for separating the oil in the oil-water separation container into oil-water, and measuring means for measuring the conductivity of the liquid separated in the oil-water separation container And a conversion means for converting the conductivity into the concentration,
Discharging means for discharging the liquid in the oil / water separation container, supply means for supplying a certain amount of pure water in the pure water storage container to the oil / water separation container, and stirring means for stirring the pure water in the oil / water separation container A water-based cleaning liquid deterioration monitoring device comprising: