JPH0943181A - Concentration measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously and individually measure the concentration of soluble substance, that of suspension substance, and that of total solid content by using the conductivity of a liquid to be measured and by performing an operation based on the relationship between a conductivity which is obtained in advance and the concentration of the soluble substance. SOLUTION: A signal detected by a conductivity detector 2 is sent to a conductivity meter converter 4 and is inputted to a soluble substance concentration operator 6 as a conductivity signal, the concentration of the soluble substance is obtained based on a calibration curve for indicating the relationship between the conductivity which is stored in advance and the concentration of the soluble substance, and a concentration signal is outputted externally and at the same time is inputted to a suspension substance(SS) concentration operator 7. On the other hand, a signal detected by a microwave type densitometer 3 is sent to a microwave type densitometer converter 5, is converted to a total solid content (TS) concentration signal and is outputted externally, and at the same time is outputted to the operator 7. The operator 7 subtracts the concentration of the soluble substance from the TS concentration, obtains an SS concentration signal, and outputs it externally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the concentration of a liquid to be measured containing suspended solids and soluble substances, such as sewage sludge and pulp, and particularly to the concentration of soluble substances and suspended solids. The present invention relates to a concentration measuring device capable of separately and continuously measuring the concentration of a substance and the concentration of the total solid content of a suspension substance and a soluble substance.

[0002]

2. Description of the Related Art Conventionally, suspended substances (SS: Suspended Solid) such as sewage sludge and pulp are used.
As a device for measuring the concentration of the solution to be measured containing s) and a soluble substance, optical, ultrasonic, microwave, and dry weight method densitometers have been used.

However, this type of densitometer can measure either the concentration of suspended solids or the total solids (TS) concentration of the suspended solids and soluble solids.

For example, in an optical or ultrasonic densitometer, for example, as shown in the principle diagram of FIG. 7, an incident wave is scattered by particles suspended in a liquid, so that a transmitted wave is attenuated. Therefore, the concentration of the suspended substance is measured by measuring this attenuation rate.

Therefore, in an optical or ultrasonic densitometer,
Only suspended substances can be detected, and substances dissolved in the liquid cannot be detected. Some optical densitometers measure the amount of light scattered by suspended particles to measure the concentration of suspended solids, but even with this system, only suspended solids can be detected. is there.

Further, the microwave type densitometer is based on the fact that the electric constants such as the dielectric constant and the electric conductivity of the liquid to be measured change depending on the concentration. Since this electric constant changes depending on the amount of suspended substances and the amount of soluble substances, the microwave type is a concentration meter of total solids.

Therefore, the microwave type densitometer cannot measure the concentration of only the suspended substance. further,
In the dry weight method concentration meter, a certain amount of a sample is taken from the liquid to be measured and weighed, and then this sample is heated with a heater to evaporate a solvent such as water, and the weight after drying is measured. The total solid content concentration is obtained by dividing the weight after drying by the weight before drying. However, in this dried solid content, a suspended matter content and a soluble material are contained in a precipitated state.

Therefore, the dry gravimetric densitometer is a densitometer of total solids, and cannot measure the concentration of only the suspended substance. By the way, in the process of handling the liquid to be measured containing the suspended substance and the soluble substance, for example, the process such as the treatment of sewage sludge, the suspended substance and the total solid content, and the soluble substance [(total solid substance Since it is possible to better manage the concentration of (min)-(suspended substance), it is necessary to measure both the suspended substance and the total solid content.

However, as described above, the conventional densitometers of each type can measure only the concentration of the suspended solids or the total solid content, and when it is desired to individually measure the concentration, the so-called manual analysis is required. In the case of the method and sludge, there is only the method of individually measuring the suspended solids and the total solids by the manual analysis method specified in “Sewage test method”. However, this manual analysis method has a problem that the operation is complicated, skill is required, and continuous measurement cannot be performed.

[0010]

As described above, in the conventional densitometer, when measuring the concentration of the liquid to be measured containing the suspended substance and the soluble substance, either the concentration of the suspended substance or the total solid content is measured. There was a problem that it could only measure.

An object of the present invention is to measure the concentration of a soluble substance, the concentration of a suspended substance, and the concentration of total solids separately and continuously when measuring the concentration of a liquid to be measured containing a suspended substance and a soluble substance. An object of the present invention is to provide a concentration measuring device capable of performing the above.

[0012]

In order to achieve the above object, in an apparatus for measuring the concentration of a solution to be measured containing a suspended substance and a soluble substance, first, in the invention corresponding to claim 1, Using the conductivity detection means for detecting the conductivity of the measurement liquid and the value of the conductivity detected by the conductivity detection means, the calculation is performed based on the relational expression between the conductivity and the soluble substance concentration obtained in advance. And a soluble substance concentration calculating means for calculating the concentration of the soluble substance.

In the invention according to claim 2, the conductivity determined in advance using the conductivity detecting means for detecting the conductivity of the liquid to be measured and the value of the conductivity detected by the conductivity detecting means. A soluble substance concentration calculating means for calculating the concentration of the soluble substance by performing an operation based on the relational expression between the rate and the soluble substance concentration, and a total solid content concentration detecting means for detecting the total solid content concentration of the liquid to be measured. , Based on the soluble substance concentration calculated by the soluble substance concentration calculation means and the total solid content concentration detected by the total solid content concentration detection means, the calculation of (total solid content concentration-soluble substance concentration) is performed. And a suspension substance concentration calculating means for calculating the concentration of the suspension substance.

Further, in the invention corresponding to claim 3, the conductivity determined in advance using the conductivity detecting means for detecting the conductivity of the liquid to be measured and the value of the conductivity detected by the conductivity detecting means. And a soluble substance concentration calculating means for calculating the concentration of the soluble substance by performing a calculation based on the relational expression between the rate and the concentration of the soluble substance, and a suspended substance concentration detecting means for detecting the concentration of the suspended substance in the liquid to be measured. , (Suspended substance concentration + soluble substance concentration) is calculated based on the soluble substance concentration calculated by the soluble substance concentration calculation means and the suspended substance concentration detected by the suspended substance concentration calculation means. And a total solid content concentration calculating means for calculating the total solid content concentration.

On the other hand, in the invention corresponding to claim 4, in the concentration measuring device of the invention according to any one of claims 1 to 3, a part of the suspended solid (solid content) in the liquid to be measured is used. (Filtering or fibrous material) is added to detect the conductivity of the filtrate by the filtering means.

Further, in the invention according to claim 5, in the concentration measuring device of the invention according to claim 4, backwashing means for backwashing the filter to wash away solid matters and fibrous matters adhering to the filter. Is added.

[0017]

Therefore, first, in the concentration measuring device of the invention according to claim 1, the conductivity detecting means detects the conductivity of the liquid to be measured, and the soluble substance concentration calculating means calculates the value of the conductivity. Is used to calculate the concentration of the soluble substance by performing an arithmetic operation from the relational expression between the conductivity and the concentration of the soluble substance which is obtained in advance.

Thus, the concentration of the soluble substance can be measured. In the concentration measuring device of the invention corresponding to claim 2, the conductivity detecting means detects the conductivity of the liquid to be measured, and the soluble substance concentration calculating means uses this conductivity value in advance. The concentration of the soluble substance is calculated by calculating from the relational expression between the obtained conductivity and the concentration of the soluble substance. Further, the total solid content concentration detecting means detects the total solid content concentration of the liquid to be measured, and the suspended solid concentration calculating means, the soluble substance concentration calculated above and the total solid content concentration detected above. From (total solid content concentration-soluble substance concentration), the concentration of the suspended substance is calculated.

Thus, the concentration of the soluble substance, the concentration of the suspended substance, and the concentration of the total solid content can be measured separately and continuously. Further, in the concentration measuring device of the invention corresponding to claim 3, the conductivity detecting means detects the conductivity of the liquid to be measured, and the soluble substance concentration calculating means uses the value of the conductivity in advance. The concentration of the soluble substance is calculated by calculating from the relational expression between the obtained conductivity and the concentration of the soluble substance. In addition, with suspended substance concentration detection means,
The concentration of suspended solids in the liquid to be measured is detected, and the total solid content concentration calculating means calculates the concentration of the soluble substances calculated above and the concentration of the suspended solids detected above (suspended substance concentration + solubility Substance concentration) to calculate the total solid content concentration.

Thus, the concentration of the soluble substance, the concentration of the suspended substance, and the concentration of the total solid content can be measured separately and continuously. On the other hand, in the concentration measuring device of the invention according to claim 4, when measuring the concentration of the soluble substance, the concentration of the suspended substance, and the concentration of the total solid content, the suspended substance in the liquid to be measured is filtered by the filter means. By removing a part (large solid content or fibrous content as seeds) of the filtrate and measuring the conductivity of the filtrate, the conductivity can be stably measured for a long period of time.

Further, in the concentration measuring apparatus of the invention according to claim 5, the filter means removes the solid content and the fibrous content of the suspended substance in the liquid to be measured, and the conductivity of the filtrate is adjusted. When the measurement is performed, the backwashing means backwashes the filter to wash away the solid content and the fibrous content attached to the filter, so that the conductivity can be stably measured for a longer period of time.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the principle of the present invention will be described. As a result of measuring and investigating the relationship between the soluble substance concentration and the conductivity of the sewage sludge, it was found that the present invention has an extremely good linear relationship as shown in FIG. This is because in the case of sewage sludge, since most of the soluble substances are salts such as NaCl, they are ionized in water to increase the conductivity. Further, similar to the sewage sludge, if the solution to be measured is such that the soluble substance is almost a salt, the soluble substance concentration and the conductivity have an extremely good linear relationship, as in the case shown in FIG. It is in.

Therefore, in the present invention, the conductivity of the liquid to be measured is detected using a conductivity meter, and the detected conductivity value is used to determine the conductivity and the soluble substance concentration as shown in FIG. The concentration of the soluble substance can be calculated by performing the calculation based on the relational expression with.

Further, as shown in the block diagram of FIG. 2 as one form of its principle configuration, a conductivity meter and a total solid content concentration meter such as a microwave type or a dry weight method for detecting the total solid content concentration are shown. An apparatus in which the total solid content concentration detection value and the soluble substance concentration obtained from the electrical conductivity are set to (total solid content concentration-
The soluble substance concentration = suspended substance concentration) is calculated to obtain the suspended substance concentration, and the total solid content concentration value and the suspended substance concentration value are output. The soluble substance concentration value may also be output.

Further, as shown in the block diagram of FIG. 3 as another form of the principle configuration, a conductivity meter and a suspended substance concentration meter such as an optical type or an ultrasonic type for detecting the suspended substance concentration are provided. An apparatus combining the above is configured to calculate (suspended substance concentration + soluble substance concentration = total solid content concentration) from the suspended substance concentration detected value and the soluble substance concentration obtained from the conductivity to calculate the total solid content. Determine the concentration and output the suspended solids concentration value and total solids concentration value. The soluble substance concentration value may also be output.

An embodiment of the present invention based on the above principle will be described below in detail with reference to the drawings. (First Embodiment) FIG. 4 is a block diagram showing an example of the overall configuration when the concentration measuring device of the present embodiment is applied to the measurement of sewage sludge concentration.

That is, as shown in FIG. 4, the concentration measuring apparatus of the present embodiment detects the conductivity attached to the sewage sludge piping line 1 through which the sewage sludge, which is the liquid to be measured containing the suspended substance and the soluble substance, flows. Vessel 2, a microwave type densitometer 3 which is a means for detecting the concentration of all solids, a conductivity meter converter 4,
It comprises a soluble substance concentration calculator 6, a microwave type concentration meter converter 5, and a suspended substance concentration calculator (SS concentration calculator) 7.

Here, the conductivity detector 2 detects the conductivity of the sewage sludge which is the liquid to be measured. The microwave densitometer 3 detects the total solid content concentration (TS concentration) of the sewage sludge that is the liquid to be measured.

On the other hand, the conductivity meter converter 4 converts the detection signal from the conductivity detector 2 into a conductivity signal and outputs it. Further, the soluble substance concentration calculator 6 stores in advance a calibration curve showing the relationship between the conductivity and the soluble substance concentration as shown in FIG. 1, and based on this calibration curve,
The calculation is performed using the value of the conductivity signal from the conductivity meter converter 4 to calculate the concentration of the soluble substance.

Further, the microwave densitometer converter 5 is
The detection signal from the microwave densitometer 3 is converted into a total solid content concentration signal (TS concentration signal) and output. Furthermore, the suspended substance concentration calculator 7 calculates, based on the soluble substance concentration calculated by the soluble substance concentration calculator 6 and the value of the total solid content concentration signal from the microwave type densitometer converter 5, The calculation of (total solid content concentration-soluble substance concentration) is performed to calculate the concentration of the suspended substance, and the suspended substance concentration signal (SS concentration signal) is output.

Next, the operation of the concentration measuring apparatus of the present embodiment constructed as above will be described. In FIG. 4, the signal detected by the conductivity detector 2 is sent to the conductivity meter converter 4, and is input from the conductivity meter converter 4 to the soluble substance concentration calculator 6 as a conductivity signal. The soluble substance concentration calculator 6 stores in advance a calibration curve showing the relationship between the electrical conductivity and the soluble substance concentration as shown in FIG. 1, and based on this calibration curve, the conductivity value is used to determine the solubility. The concentration of the active substance is obtained, and this concentration signal is input to the suspended substance concentration calculator 7.

On the other hand, the signal detected by the microwave type densitometer detector 3 is sent to the microwave type densitometer converter 5, and in this microwave type densitometer converter 5, the total solid content concentration signal (TS concentration signal ), Is output to the outside as a TS concentration signal, and is input to the suspended substance concentration calculator 7.

Further, the suspension substance concentration calculator 7 calculates (concentration of total solid content-concentration of soluble substance) = suspension substance concentration and outputs it as a suspension substance concentration signal (SS concentration signal) to the outside. It

The soluble substance concentration calculator 6 may output the soluble substance concentration signal independently. As described above, the concentration measuring device according to the present embodiment includes the conductivity detector 2 for detecting the conductivity of the sewage sludge, which is the liquid to be measured containing the suspended substance and the soluble substance, and the sewage sludge, which is the liquid to be measured. Microwave type densitometer 3 which is a total solid content concentration detecting means for detecting the total solid content concentration (TS concentration) of, and a conductivity detector 2
A conductivity meter converter 4 for converting the detection signal from the sensor into a conductivity signal and outputting the conductivity signal, and a calibration curve showing the relationship between the conductivity and the concentration of the soluble substance are stored, and the conductivity meter is based on this calibration curve. The soluble substance concentration calculator 6 for calculating the concentration of the soluble substance by performing calculation using the value of the conductivity signal from the converter 4 and the detection signal from the microwave densitometer 3 are the total solid content concentration signals. Microwave type densitometer converter 5 for converting and outputting (TS concentration signal), soluble substance concentration calculated by the soluble substance concentration calculator 6 and total solid content from the microwave type densitometer converter 5 Based on the value of the concentration signal, (total solid content concentration-
The concentration of the soluble substance is calculated to calculate the concentration of the suspended substance, and the suspended substance concentration calculator 7 outputs a suspended substance concentration signal (SS concentration signal).

Therefore, when measuring the concentration of sewage sludge, which is the liquid to be measured containing suspended substances and soluble substances, the concentration of soluble substances, the concentration of suspended substances (SS concentration), and the concentration of total solids (TS concentration) It is possible to separately obtain and as measured values and to continuously measure.

As a result, the above-mentioned conventional problems can be solved, the process can be managed finely, and the process operation efficiency can be improved.

(Second Embodiment) FIG. 5 is a block diagram showing an example of the overall structure when the concentration measuring apparatus of this embodiment is applied to the measurement of sewage sludge concentration.

That is, as shown in FIG. 5, the concentration measuring apparatus according to the present embodiment detects the conductivity, which is attached to the sewage sludge piping line 11 through which the sewage sludge which is the liquid to be measured containing the suspended substance and the soluble substance flows. Device 12, an ultrasonic densitometer 13 as a suspended matter concentration detecting means, and a conductivity meter converter 14
, Soluble substance concentration calculator 16, ultrasonic type densitometer converter 15, total solids concentration calculator (TS concentration calculator) 17
It is composed of

Here, the conductivity detector 12 detects the conductivity of the sewage sludge which is the liquid to be measured. The ultrasonic densitometer 13 detects the concentration of suspended matter (SS concentration) in the sewage sludge, which is the liquid to be measured.

On the other hand, the conductivity meter converter 14 converts the detection signal from the conductivity detector 12 into a conductivity signal and outputs it. Further, the soluble substance concentration calculator 16 stores in advance a calibration curve showing the relationship between the conductivity and the soluble substance concentration as shown in FIG. 1, and based on this calibration curve, conductivity meter conversion is performed. The calculation is performed using the value of the conductivity signal from the container 14 to calculate the concentration of the soluble substance.

Further, the ultrasonic densitometer converter 15 converts the detection signal from the ultrasonic densitometer 13 into a suspended substance concentration signal (SS concentration signal) and outputs it. Furthermore, the total solid content concentration calculator 17 calculates, based on the soluble substance concentration calculated by the soluble substance concentration calculator 16 and the value of the suspended substance concentration signal from the ultrasonic densitometer converter 15, The calculation of (concentration of suspended substance + concentration of soluble substance) is performed to calculate the concentration of the total solid content, and the total solid content concentration signal (TS concentration signal) is output.

Next, the operation of the concentration measuring apparatus of the present embodiment constructed as above will be described. In FIG. 5, the signal detected by the conductivity detector 12 is the conductivity meter converter 14
Is sent to the soluble substance concentration calculator 16 as a conductivity signal from the conductivity meter converter 14. The soluble substance concentration calculator 16 stores in advance a calibration curve showing the relationship between the electrical conductivity and the soluble substance concentration as shown in FIG. 1, and based on this calibration curve, the conductivity value is used to determine the dissolution. The concentration signal of the solid substance is calculated, and this concentration signal is used as the total solid concentration calculator 17.
Is input to

On the other hand, the signal detected by the ultrasonic type densitometer detector 13 is sent to the ultrasonic type densitometer converter 15, and in this ultrasonic type densitometer converter 15, the suspended substance concentration signal (SS concentration signal ), Is output to the outside as an SS concentration signal, and is input to the total solids concentration calculator 17.

Further, in the total solid content concentration calculator 17,
(Suspension substance concentration + Soluble substance concentration) = Total solid content concentration is calculated and output to the outside as a total solid content concentration signal (TS concentration signal).

The soluble substance concentration calculator 16 may independently output the soluble substance concentration signal.
As described above, the concentration measuring device according to the present embodiment includes the conductivity detector 12 that detects the conductivity of the sewage sludge, which is the liquid to be measured containing the suspended substance and the soluble substance, and the sewage sludge, which is the liquid to be measured. 1. An ultrasonic densitometer 13 for detecting the concentration of suspended solids (SS concentration), a conductivity meter converter 14 for converting the detection signal from the conductivity detector 12 into a conductivity signal and outputting the same, and FIG. The calibration curve showing the relationship between the conductivity and the concentration of the soluble substance as shown in FIG. 3 is stored, and the calculation is performed using the value of the conductivity signal from the conductivity meter converter 14 based on this calibration curve, Ultrasonic concentration meter conversion for converting the detection signal from the soluble substance concentration calculator 16 for calculating the concentration of the soluble substance and the ultrasonic concentration meter 13 into a suspension substance concentration signal (SS concentration signal) and outputting the signal. Dissolution calculated by vessel 15 and soluble substance concentration calculator 16 Substance concentration and ultrasonic densitometer transducer 1
Based on the value of the suspended solids concentration signal from 5, the calculation of (suspended solids concentration + soluble substance concentration) is performed to calculate the concentration of total solids, and the total solids concentration signal (TS concentration signal) is calculated. It is composed of a total solid content concentration calculator 17 for outputting.

Therefore, when measuring the concentration of sewage sludge, which is the liquid to be measured containing suspended substances and soluble substances, the soluble substance concentration, total solids concentration (TS concentration), and suspended substance concentration (SS concentration) It is possible to separately obtain and as measured values and to continuously measure.

As a result, the above-mentioned conventional problems can be solved, the process can be managed finely, and the process operation efficiency can be improved.

(Third Embodiment) FIG. 6 is a block diagram showing an example of the overall structure when the concentration measuring apparatus of this embodiment is applied to the measurement of sewage sludge concentration. Will be omitted and the description will be omitted, and only different parts will be described here.

That is, in the concentration measuring apparatus of this embodiment, as shown in FIG. 6, a filter 25 composed of, for example, a mesh or a UF membrane is provided on the pipe branching from the sewage sludge pipe line 1. The filter 25 is provided to guide the sewage sludge to the conductivity detector 2.

As a result, a part (mainly large solid content and fibrous content) of suspended matter in the sewage sludge is removed by the filter 25, and the conductivity of the filtrate is detected by the conductivity detector 2. ing.

On the other hand, the valve 21 is provided on the primary side of the filter 25 and the valve 23 is provided on the secondary side of the filter 25 on the pipe branched from the sewage sludge pipe line 1.

Further, a drain pipe is provided branching from the branch pipe, and a valve 22 is provided on the drain pipe. Further, a valve 24 communicating with the tap water supply port is provided on the secondary side of the filter 25.

Furthermore, a cleaning controller 20 for controlling the opening and closing of each of the valves 21 to 24 is provided. These constitute a backwashing means for backwashing the filter 25 to wash away the solid content and the fiber content attached to the filter 25.

Next, the operation of the concentration measuring apparatus of the present embodiment having the above-mentioned structure will be described. In addition, here
Only parts different from the operation of the first embodiment will be described.

In FIG. 6, a part of the sludge flow is branched from the sewage sludge piping line 1 and guided to the filter 25 via the valve 21 (normally open). And this filter 2
The filtrate from which large solids and fibrous components have been removed in 5 flows to the conductivity detector 2 via the valve 23 (normally open), where the conductivity is detected. The filtrate after the conductivity detection is discharged to the outside from the drain pipe.

The valve 22 provided on the primary side of the filter 25 is normally closed. Also, the filter 25
The valve 24 provided on the secondary side is normally closed. On the other hand, the cleaning controller 20 causes the filter 25
At the time of cleaning, the opening / closing of each of the valves 21 to 24 is controlled.

That is, since the primary side of the filter 25 becomes clogged due to long-term use and the filtrate cannot be sufficiently obtained, the filter 25 is periodically replaced with tap water every four hours, for example. It is preferable to perform washing. Then, at the time of this backwashing, the washing controller 20
The valves 21 and 23 are closed, the valve 22 is opened, and the valve 24 is opened to filter the tap water with the filter 25.
Of the filter 25, the solid content and the fibrous content adhering to the primary side of the filter 25 are washed away by the water pressure, and are discharged to the outside from the drain pipe through the valve 22. After completion of this backwashing operation, the valves 22 and 24 are closed,
The valves 21 and 23 are opened to return to the normal measurement state.

During backwashing, the conductivity value is held at the value just before the start of backwashing. As described above, in addition to the concentration measuring device of the first embodiment, the concentration measuring device of the present embodiment includes a part of the suspended matter of the sewage sludge (solid content or fibrous content) in the liquid to be measured. ) Is removed, and this filter 25 is backwashed to filter 2
Valves 21 to wash away solids and fibrous materials attached to 5
24 and a cleaning controller 20 for controlling the opening and closing thereof are provided.

Therefore, when measuring the concentration of sewage sludge, which is the liquid to be measured containing suspended substances and soluble substances, the soluble substance concentration, total solids concentration (TS concentration), and suspended substance concentration (SS concentration) It becomes possible to separately obtain and as measured values, and to measure continuously and stably for a longer period of time.

That is, in general, when it is attempted to continuously detect the electrical conductivity of sewage sludge, the electrode part of the detector may be clogged with large solids or fibrous components in the sewage sludge for a long time. Since it may be difficult to continuously detect the conductivity, it is possible to stably detect the conductivity for a long time by detecting the conductivity of the filtrate applied with the filter 25 as in the present embodiment. It will be possible.

As a result, the above-mentioned conventional problems can be solved, the process can be managed finely, and the efficiency of the process operation can be further improved.

The present invention is not limited to the above embodiments, but can be implemented in the same manner as described below. (A) In the third embodiment, a filter 25 for removing a part (solid content or fibrous content) of suspended substances of sewage sludge in the liquid to be measured, and a filter 25 for backwashing the filter 25 are used. Valve 21 for flushing solids and fibrous materials adhering to 25
~ 24 and the cleaning controller 20 for controlling the opening and closing
The case where the backwashing means consisting of the above is added to the concentration measuring device of the first embodiment has been described, but the present invention is not limited to this, and the filter 25 and the backwashing means are provided in the second embodiment. It may be configured to be added to the concentration measuring device of.

(B) In the third embodiment, a part (solid content or fibrous content) of suspended substances of sewage sludge in the liquid to be measured.
The filter 25 for removing the water and the backwashing means including the valves 21 to 24 for backwashing the filter 25 to wash away the solid content and the fiber content adhering to the filter 25 and the wash controller 20 for controlling the opening and closing of the filter are used together. Although the case has been described, the present invention is not limited to this, and the backwashing means may be omitted and only the filter 25 may be provided in the concentration measuring apparatus of the first or second embodiment.

[0064]

As described above, in the device for measuring the concentration of the measured liquid containing the suspended substance and the soluble substance, first, according to the invention corresponding to claim 1, the conductivity of the measured liquid is measured. Conductivity detecting means for detecting, and using the value of the conductivity detected by the conductivity detecting means, the solubility of the soluble substance by performing a calculation based on the relational expression of the conductivity and the soluble substance concentration obtained in advance. Since a soluble substance concentration calculating means for calculating the concentration is provided, a concentration measuring device capable of measuring the concentration of the soluble substance when measuring the concentration of the solution to be measured containing the suspended substance and the soluble substance is provided. Can be provided.

According to the invention corresponding to claim 2,
Using the conductivity detecting means for detecting the conductivity of the liquid to be measured and the value of the conductivity detected by the conductivity detecting means, the calculation is performed based on the relational expression between the conductivity and the soluble substance concentration obtained in advance. The soluble substance concentration calculation means for calculating the concentration of the soluble substance, the total solid content concentration detection means for detecting the total solid content concentration of the liquid to be measured, and the soluble substance calculated by the soluble substance concentration calculation means Based on the concentration and the total solid content concentration detected by the total solid content concentration detection means, the calculation of (total solid content concentration-soluble substance concentration) is performed to calculate the concentration of the suspended substance Since it is equipped with and, the concentration of the soluble substance, the concentration of the suspended substance, and the concentration of the total solid content are measured separately and continuously when measuring the concentration of the measured liquid containing the suspended substance and the soluble substance. Possible Measuring device can be provided.

Further, according to the invention corresponding to claim 3, it is obtained in advance by using the conductivity detecting means for detecting the conductivity of the liquid to be measured and the value of the conductivity detected by the conductivity detecting means. The soluble substance concentration calculating means for calculating the concentration of the soluble substance by performing the calculation based on the relational expression between the conductivity and the concentration of the soluble substance, and the suspended substance concentration detection for detecting the concentration of the suspended substance of the liquid to be measured Means, and a calculation of (suspended substance concentration + dissolved substance concentration) based on the soluble substance concentration calculated by the soluble substance concentration calculation device and the suspended substance concentration detected by the suspended substance concentration calculation device. Since the total solid content concentration calculating means for calculating the total solid content concentration is provided, the concentration of the soluble substance, the concentration of the suspended substance, and the concentration of the suspended substance at the time of measuring the concentration of the solution to be measured containing the suspended substance and the soluble substance,
It is possible to provide a concentration measuring device capable of separately and continuously measuring the concentration of total solids.

On the other hand, according to the invention corresponding to claim 4,
In the concentration measuring device of the invention corresponding to any one of claims 1 to 3, filter means for removing a part (solid content or fibrous content) of suspended matter in the liquid to be measured is added. Since the conductivity of the filtrate is detected by the filter means, the concentration of the soluble substance, the concentration of the suspended substance, and the concentration of the total solid content are measured when measuring the concentration of the liquid to be measured containing the suspended substance and the soluble substance. It is possible to provide a concentration measuring device capable of separately and continuously measuring each of them stably for a long period of time.

According to the invention corresponding to claim 5,
In the concentration measuring device of the invention according to claim 4,
Since a backwashing means for washing back the filter to wash away the solids and fibrous substances adhering to the filter was added, when measuring the concentration of the solution to be measured containing suspended substances and soluble substances, the soluble substances It is possible to provide a concentration measuring device capable of measuring the concentration, the concentration of suspended solids, and the concentration of total solids separately, continuously, and stably for a longer period of time.

[Brief description of drawings]

FIG. 1 is a characteristic diagram showing the relationship between the concentration of a soluble substance and the conductivity, which is the basis of the present invention.

FIG. 2 is a block diagram showing one form of the principle configuration of the concentration measuring device according to the present invention.

FIG. 3 is a block diagram showing another form of the principle configuration of the concentration measuring device according to the present invention.

FIG. 4 is a block diagram showing a first embodiment of the concentration measuring device according to the present invention.

FIG. 5 is a block diagram showing a second embodiment of the concentration measuring device according to the present invention.

FIG. 6 is a block diagram showing a third embodiment of the concentration measuring device according to the present invention.

FIG. 7 is a principle diagram showing an example of a conventional densitometer.

[Explanation of symbols]

 1 ... Sewage sludge piping line, 2 ... Conductivity detector, 3 ... Microwave densitometer, 4 ... Conductivity meter converter, 5 ... Microwave densitometer converter, 6 ... Soluble substance concentration calculator, 7 ... SS suspended substance concentration calculator (SS concentration calculator), 11 ... sewage sludge piping line, 12 ... conductivity detector, 13 ... ultrasonic densitometer detector, 14 ... conductivity meter converter, 15 ... super Sound wave type densitometer converter, 16 ... Soluble substance concentration calculator, 17 ... Total solid content concentration calculator (TS concentration calculator), 20 ... Cleaning controller, 21, 22, 23, 24 ... Valve, 25 ... Filter .

Claims (5)

[Claims] 1. An apparatus for measuring the concentration of a liquid to be measured containing a suspended substance and a soluble substance, wherein the electric conductivity is detected by the electric conductivity detecting unit for detecting the electric conductivity of the liquid to be measured. And a soluble substance concentration calculating means for calculating the concentration of the soluble substance by performing an operation based on a relational expression between the conductivity and the soluble substance concentration obtained in advance using the value of the electrical conductivity. A concentration measuring device characterized by the above. 2. An apparatus for measuring the concentration of a liquid to be measured containing a suspended substance and a soluble substance, wherein the electric conductivity is detected by the electric conductivity detecting unit for detecting the electric conductivity of the liquid to be measured. Using the value of the conductivity, a soluble substance concentration calculating means for calculating the concentration of the soluble substance by performing a calculation based on a relational expression between the conductivity and the soluble substance concentration obtained in advance, the liquid to be measured Based on the total solid content concentration detection means for detecting the total solid content concentration of, the soluble substance concentration calculated by the soluble substance concentration calculation means and the total solid content concentration detected by the total solid content concentration detection means And a suspension substance concentration calculating means for calculating the concentration of the suspended substance by performing a calculation of (total solid content concentration-soluble substance concentration). 3. An apparatus for measuring the concentration of a liquid to be measured containing a suspended substance and a soluble substance, wherein the electric conductivity is detected by the electric conductivity detecting unit for detecting the electric conductivity of the liquid to be measured. Using the value of the conductivity, a soluble substance concentration calculating means for calculating the concentration of the soluble substance by performing a calculation based on a relational expression between the conductivity and the soluble substance concentration obtained in advance, the liquid to be measured Based on the suspended substance concentration detection means for detecting the suspended substance concentration of, and the soluble substance concentration calculated by the soluble substance concentration calculation means and the suspended substance concentration detected by the suspended substance concentration calculation means And a total solid content concentration calculating means for calculating a total solid content concentration by performing a calculation of (suspended substance concentration + soluble substance concentration). 4. The method according to any one of claims 1 to 3.
In the concentration measuring device according to the item, a part (solid content or fibrous content) of suspended matter in the measured liquid
A concentration measuring device characterized in that a filter means for removing is added, and the conductivity of the filtrate by the filter means is detected. 5. The concentration measuring device according to claim 4, wherein a backwashing means for backwashing the filter to wash away solid matter and fibrous matter adhering to the filter is added. The concentration measuring device according to claim 4.