JP7295598B1 - Coagulant addition amount adjustment device and coagulant addition amount adjustment method - Google Patents

Abstract

An object of the present invention is to adjust the amount of a flocculant added to turbid water. A coagulant addition amount adjustment device 100 includes a raw water inlet 102 that takes in a part of turbid water after addition of a coagulant, a laser sensor 108 that measures the turbid water taken in from the raw water inlet 102, and a laser sensor. and a control unit that performs processing for adjusting the addition amount of the coagulant to be added to the turbid water based on the measurement result. [Selection drawing] Fig. 2

Description

TECHNICAL FIELD The present invention relates to a coagulant addition amount adjustment device and a coagulant addition amount adjustment method.

The following muddy water treatment systems are known. In this turbid water treatment system, information on the pH value and turbidity of the treated water is acquired, and the amount of the agent for controlling the pH value and the agent for controlling the turbidity is determined according to the acquired information. , to inject the determined addition amount of the drug (for example, Patent Document 1).

JP 2021-16827 A

In the conventional turbid water treatment system, a turbidity meter equipped with an irradiation part and a light receiving part is used. was measured. As described above, when a turbidity meter is installed in a tank to measure the turbidity of water, the measuring part is immersed in turbid water and becomes dirty, which may reduce the measurement accuracy. Moreover, in order to avoid this, it is necessary to periodically clean the measurement unit, which is troublesome for maintenance. Therefore, there is a demand for a technique for solving such a problem, but conventionally, no study has been made on a technique for solving this problem.

The coagulant addition amount adjustment device according to the present invention includes a raw water inlet that takes in part of the turbid water after addition of the coagulant, a laser sensor that measures the turbid water taken in from the raw water inlet, and based on the measurement results of the laser sensor. A control unit that performs processing for adjusting the amount of coagulant to be added to the turbid water, the control unit opens the raw water inlet automatic valve to take in a part of the turbid water from the raw water inlet and the outlet automatic valve is closed, and when overflow water is detected by the overflow water detection sensor, the raw water inlet automatic valve is closed, and the measurement is performed by the laser sensor until the preset measurement time elapses. A process for adjusting the amount of coagulant added is performed, and when the measurement time elapses, an automatic drain valve is opened to drain muddy water .
The method for adjusting the amount of coagulant added according to the present invention includes a raw water inlet that takes in part of the turbid water after addition of the coagulant, a laser sensor that measures the turbid water taken in from the raw water inlet, and a measurement result by the laser sensor. A coagulant addition amount adjustment method executed by a coagulant addition amount adjustment device including a control unit that performs processing for adjusting the addition amount of the coagulant to be added to turbid water, wherein the control unit is a raw water inlet Open the automatic valve to take in part of the turbid water from the raw water inlet, close the automatic drain valve, and close the automatic valve at the raw water inlet when overflow water is detected by the overflow water detection sensor, until the measurement time elapses. Measurement is performed with a laser sensor, processing is performed to adjust the amount of coagulant to be added to the turbid water based on the measurement results of the laser sensor, and after the measurement time has elapsed, the automatic drain valve is opened to drain the turbid water. characterized by

According to the present invention, since a laser sensor capable of measuring turbid water without contact is used to measure turbid water, detection accuracy is deteriorated due to contamination of the measuring part, which has been a problem in conventional immersion type turbidity meters. It is possible to eliminate deterioration and maintenance complexity.

It is the figure which showed typically the flow of turbid water treatment in the turbid water treatment equipment using a coagulant addition amount adjusting device. It is a figure which shows the structure of one Embodiment of a coagulant addition amount adjustment apparatus. FIG. 4 is a flowchart showing the flow of a coagulant addition amount adjustment process using the coagulant addition amount adjustment device; FIG. 10 is an example of a graph showing the correlation between the measured value (%) of the laser sensor and the amount of suspended solids SS (mg/L); FIG.

The coagulant addition amount adjustment device in the present embodiment automatically adjusts the addition amount of the coagulant when treating turbid water by adding a coagulant to turbid water generated at a factory or construction site to precipitate suspended solids. used to adjust In this embodiment, muddy water is treated as follows.

Muddy water generated at factories and construction sites is collected in raw water tanks. An initial amount of the inorganic flocculant is added to the turbid water based on the initial set value of the flocculant addition amount obtained in advance, and the mixture is stirred. In addition, addition of an inorganic flocculant is performed using a well-known method. Here, for example, it may be added with a stirrer attached to the raw water tank, or it may be added with a line mixer (pipe with a mixing stirrer) by injecting into a pipe sending to the reaction tank using a raw water pump. Alternatively, it may be sent to the reaction tank using a raw water pump and added with a reaction tank stirrer. Thereafter, an initial amount of polymer flocculant is added to the turbid water based on an initial set value for the amount of flocculant to be added that has been obtained in advance. The polymer flocculant may be added using a reactor stirrer, but when the inorganic flocculant is mixed in the reactor, a polymer reactor is provided and added. The turbid water after addition of the coagulant is transferred to the sedimentation tank, and part of the turbid water after the addition of the coagulant is taken into the coagulant addition amount adjusting device in the present embodiment. In the coagulant addition amount adjustment device, as will be described later, the turbid water taken in is measured by a laser sensor, and the addition amount of the coagulant is adjusted based on the measurement result. FIG. 1 is a diagram schematically showing the flow of turbid water treatment in a turbid water treatment facility using the coagulant addition amount adjusting device 100 according to the present embodiment.

FIG. 2 is a diagram showing the configuration of one embodiment of the coagulant addition amount adjusting device according to the present embodiment. As shown in FIG. 2, the coagulant addition amount adjustment device 100 includes a raw water inlet automatic valve 101, a raw water inlet 102, an overflow water sensor 103, an overflow port 104, an automatic drain valve 105, and a drain. It is composed of a mouth 106 , a transparent measuring section 107 , a laser sensor 108 and an upper cleaning opening 109 .

In the coagulant addition amount adjustment device 100 shown in FIG. 2, when the raw water inlet automatic valve 101 is opened, part of the turbid water after addition of the coagulant can be taken into the coagulant addition amount adjustment device 100 from the raw water inlet 102. . At this time, when the automatic drain valve 105 is closed, the turbid water that is taken in accumulates in the coagulant addition amount adjusting device 100 , and when the automatic drain valve 105 is opened, the turbid water that is taken in is discharged from the drain port 106 . The overflowed turbid water is detected by the overflow water detection sensor 103 and discharged from the overflow port 104 . In addition, a cleaning upper opening 109 for cleaning the inside of the coagulant addition amount adjustment device 100 is provided in the upper portion of the coagulant addition amount adjustment device 100 .

A transparent member such as a glass tube or a vinyl chloride tube is used for the transparent measuring section 107, and a laser sensor 108 provided in the transparent measuring section 107 can measure the muddy water inside. As the laser sensor 108, a known transmissive laser discrimination sensor is used. As a result, the laser sensor 108 can measure turbid water without contact, eliminating the problems of conventional immersion-type turbidity meters, such as deterioration in detection accuracy due to contamination of the measuring section and complicated maintenance. be able to. Furthermore, conventional turbidity meters could not accurately measure when the measurement range was exceeded, or when the turbid water was strong acid, strong alkali, or high water temperature. This problem can be solved because the measurement can be performed at

Note that the coagulant addition amount adjusting device 100 in the present embodiment includes a control unit (not shown), and the control unit controls each part of the coagulant addition amount adjusting device 100 to execute processing described later. In this embodiment, the control unit is configured as a control panel in which a CPU is stored. Sensor and timer control, measurement using a laser sensor, adjustment processing of the amount of coagulant added, etc. are performed. A touch panel is attached to the control panel, and the operator can switch between manual and automatic control of each device by touching the screen. In addition, the touch panel displays the operating state display, timer time setting, measurement value and measurement result of the laser sensor, and the like.

Preparations are made in advance before using the coagulant addition amount adjusting device 100 . The contents of the advance preparation are as follows. Perform a coagulation sedimentation test to determine the initial setting value for the amount of coagulant to be added. Grasp the correlation between the amount of suspended solids SS (mg/L) and the laser sensor measurement value (%). Grasp the correlation between injection pump output, inverter frequency and pulse signal. Enter the amount of turbid water, measurement standby time, measurement time, and injection stop value (laser sensor measurement value) in the control panel.

Also, the measurement time is the time during which the laser sensor 108 is used for measurement, and is calculated in advance as follows. In the present embodiment, the measurement time is calculated according to the coagulation sedimentation rate of the waste water treatment machine to be used. For example, if the coagulant sedimentation speed is 3 m/hour and the height of the coagulant addition amount adjusting device 100 is 30 cm, then 30 cm/300 cm×60 minutes=6 minutes. In this embodiment, the measurement time is set in seconds, so 6 minutes×60 seconds=360 seconds, and 360 seconds is input to the device. The height of the coagulant addition amount adjusting device 100 is the distance from the laser part of the laser sensor 108 to the piping position of the overflow water detection sensor 103 . The wastewater treatment equipment is selected based on the amount of turbid water, treatment conditions, etc., and the coagulation sedimentation rate varies depending on the wastewater treatment equipment used.

FIG. 3 is a flow chart showing the flow of the coagulant addition amount adjustment process using the coagulant addition amount adjustment device 100 according to the present embodiment. Processing by the coagulant addition amount adjusting device 100 according to the present embodiment will be described below with reference to FIG. The coagulant addition amount adjusting apparatus 100 has an "on" button and an "off" button, and the processing shown in FIG. 3 is started when the "on" button is turned on by the operator. Further, the processing shown in FIG. 3 ends when the "off" button is turned on by the operator.

In the coagulant addition amount adjusting device 100, in step S10, the control unit opens the raw water inlet automatic valve 101 and closes the drain outlet automatic valve 105 to take in part of the turbid water after addition of the coagulant. As a result, turbid water after addition of the coagulant flows into the coagulant addition amount adjusting device 100 from the raw water inlet 102 only when the raw water pump is in operation.

In step S20, the controller determines whether overflow water is detected by the overflow water detection sensor 103 or not. If the determination in step S20 is affirmative, the process proceeds to step S30. If overflow occurs, the overflow water is drained from the overflow port 104 .

In step S<b>30 , the control unit closes the raw water inlet automatic valve 101 . The time from when the control unit performs control to close the raw water inlet automatic valve 101 to when the raw water inlet automatic valve 101 actually closes is a standby time.

In step S<b>40 , the control section starts measurement by the laser sensor 108 . In the coagulant addition amount adjusting device 100 in the present embodiment, the laser sensor 108 is provided in the transparent measurement section 107 such as a glass tube or a vinyl chloride tube as described above, and the turbid water passing through the transparent measurement section 107 is 108 can be measured. Since the measured value of the laser sensor 108 is the amount of light received (%) with respect to the amount of laser irradiation, the amount of light received (%) changes depending on the degree of turbidity of the muddy water. Therefore, based on the measured value of the laser sensor 108, the sedimentation speed of flocculated flocs in muddy water and the degree of turbidity of the supernatant water after sedimentation of flocculated flocs can be grasped. For example, if the laser sensor 108 is used, the measurement becomes possible when the amount of suspended solids SS is 100 or less.

In step S50, the controller determines whether or not the measurement by the laser sensor 108 has ended. In the present embodiment, the control unit determines that the measurement by the laser sensor 108 is completed when the measurement time calculated in advance as described above has elapsed since the measurement by the laser sensor 108 was started. Here, for example, it is assumed that the measurement by the laser sensor 108 ends when 360 seconds have passed since the measurement by the laser sensor 108 started. If the determination in step S50 is affirmative, the process proceeds to step S60.

In step S60, the control unit performs processing for adjusting the addition amount of the coagulant to be added to the turbid water based on the measurement result by the laser sensor 108 when the measurement is completed. In the present embodiment, the measured value (%) of the laser sensor 108 is compared with a preset determination threshold to determine whether the determination result is OK or NG. The threshold for determination will be described below.

In this embodiment, the relationship between the measured value of the laser sensor 108, that is, the amount of light received (%) with respect to the amount of laser irradiation and the amount of suspended solids SS (mg/L) is obtained in advance. FIG. 4 shows an example of a graph showing the correlation between the measured value (%) of the laser sensor 108 and the amount of suspended solids SS (mg/L). In the present embodiment, based on the correlation between the measured value (%) of the laser sensor 108 and the amount of suspended solids SS (mg/L) as shown in FIG. A threshold value (%) is set in advance for determining whether is OK or NG. For example, if the suspended solids amount SS, which is a general discharge standard, is set to 25 mg / L, based on the correlation between the measured value (%) of the laser sensor 108 and the suspended solids amount SS (mg / L) , the measured value of the laser sensor 108, which serves as the discharge standard, is calculated to be 46%. In the present embodiment, the determination threshold value is set to 46%, for example, and the control unit determines the determination result as NG when the measured value of the laser sensor 108 is smaller than 46%. If the amount of suspended solids SS is greater than 25 mg/L, it is judged as NG. Further, the control unit sets a threshold value so that the determination result is determined to be OK when the measured value of the laser sensor 108 is 46% or more. As a result, if the amount of suspended solids SS is 25 mg/L or less, it is determined to be OK.

When the determination result is NG, the control unit controls to increase the amount of the coagulant added to the turbid water by a predetermined amount. For example, the amount of polymer flocculant added per 1 L of turbid water is controlled to increase by 1 mg. Also, the amount of the inorganic flocculant added per 1 L of turbid water is controlled to be increased by 10 mg. On the other hand, when the determination result is OK three times in a row, the control unit controls the amount of the coagulant added to the turbid water to decrease by a predetermined amount. For example, the amount of polymer flocculant added per 1 L of turbid water is controlled to be reduced by 1 mg. Also, the amount of the inorganic flocculant added per 1 L of turbid water is controlled to be reduced by 10 mg.

In step S70, the control unit opens the drain port automatic valve 105. FIG. As a result, the muddy water taken into the coagulant addition amount adjusting device 100 is drained from the drain port 106 .

In step S80, the controller waits until the next measurement starts. An arbitrary number of seconds is set in advance as the waiting time until the start of the next measurement. In this embodiment, for example, 15 sec is set as the next measurement start waiting time, and the control unit repeats the processing from step S10 after waiting for 15 seconds. As described above, when the operator turns on the "OFF" button, the process ends.

According to the embodiment described above, the following effects can be obtained.
(1) The coagulant addition amount adjustment device 100 includes a raw water inlet 102 that takes in part of the turbid water after addition of the coagulant, a laser sensor 108 that measures the turbid water taken in from the raw water inlet 102, and measurement by the laser sensor. and a control unit that performs processing for adjusting the addition amount of the coagulant to be added to the turbid water based on the result. As a result, the laser sensor 108 can measure turbid water without contact, eliminating the problems of conventional immersion-type turbidity meters, such as deterioration in detection accuracy due to contamination of the measuring section and complicated maintenance. be able to. Furthermore, conventional turbidity meters could not accurately measure when the measurement range was exceeded, or when the turbid water was strong acid, strong alkali, or high water temperature. This problem can be solved because the measurement can be performed at

(2) The control unit compares the measured value of the laser sensor 108 with a predetermined determination threshold to determine whether the determination result is OK or NG, and if the determination result is NG, is controlled to increase the amount of coagulant added to turbid water by a predetermined amount, and when the judgment result is OK three times in a row, the amount of coagulant added to turbid water is controlled to decrease by a predetermined amount. I made it As a result, it is possible to grasp the aggregation floc sedimentation rate of muddy water and the degree of turbidity of the supernatant water after flocculation sedimentation based on the measurement value of the laser sensor 108. The amount of coagulant added can be adjusted according to the degree of turbidity of the supernatant water.

(3) The coagulant addition amount adjusting device 100 further includes a transparent measuring section 107 made of a transparent member, and the laser sensor 108 measures turbid water passing through the transparent measuring section 107 . As a result, the supernatant water after the SS portion of the muddy water has settled can be measured via the transparent measuring section 107 without bringing the laser sensor 108 into contact with the muddy water.

(4) The measurement time by the laser sensor 108 was calculated in advance according to the coagulation sedimentation speed of the wastewater treatment machine used. Thereby, the measurement accuracy of the laser sensor 108 can be improved.

(5) The control unit opens the raw water inlet automatic valve 101 to take in part of the turbid water from the raw water inlet 102, closes the drain outlet automatic valve 105, and when the overflow water detection sensor 103 detects overflow water. Close the raw water inlet automatic valve 101, measure with the laser sensor 108 until the measurement time elapses. Based on the measurement results, perform processing for adjusting the amount of coagulant added to the turbid water, and the measurement time elapses. Then, the drain port automatic valve 105 was opened to drain the muddy water. As a result, part of the turbid water can be taken in from the raw water inlet 102 and measured by the laser sensor 108, and the addition amount of the coagulant can be adjusted based on the measurement result.

(6) After opening the drain port automatic valve 105, the controller starts the next measurement after a preset standby time has elapsed. As a result, the next measurement can be started after waiting for the turbid water to be discharged from the coagulant addition amount adjusting device 100 .

(7) Furthermore, according to the coagulant addition amount adjusting device 100 of the present embodiment, the following effects can also be obtained.
(a) Labor saving By adopting a turbid water non-contact sensor, the measuring part of the sensor is less likely to get dirty, which reduces the labor and time required for cleaning.
The same operation as the coagulation sedimentation test (jar test and cylinder test) is performed automatically and continuously.
Since it is a device, the labor and time required for testing can be saved.
(b) Ensuring stable treated water quality Since there is no restriction on the measurement range, there is no increase in treated water turbidity due to deviation from the range.
Since the flocculated floc sedimentation velocity is measured by the laser sensor 108, it is possible to accurately adjust the amount to be added without being affected by individual observations, and to more reliably treat turbid water.
Since the quality of the treated water SS can be checked before the sedimentation tank, it is possible to detect deterioration of the treated water at an early stage due to troubles in the coagulant addition amount adjustment device and large fluctuations in the turbidity of the water.

-Modified example-
The coagulant addition amount adjusting device of the embodiment described above can also be modified as follows.
(1) In the above-described embodiment, the control unit controls the amount of coagulant added to turbid water to decrease by a predetermined amount when the determination result is OK three times in a row. However, the condition for controlling the amount of coagulant to be added to muddy water to decrease by a predetermined amount is not limited to the case where the judgment result is OK three times in succession. For example, when the judgment result is OK once, the amount of coagulant added to the muddy water may be controlled to decrease by a predetermined amount, or when the judgment result is OK several times in a row other than three times Alternatively, the amount of flocculant added to the turbid water may be controlled to decrease by a predetermined amount.

(2) In the embodiment described above, an example was explained in which the control unit controls the amount of coagulant added to muddy water to increase by a predetermined amount when the determination result is NG. However, the condition for controlling the amount of coagulant to be added to turbid water to increase by a predetermined amount may be the case where the judgment result is NG for a predetermined number of times. For example, the amount of the coagulant to be added to the turbid water may be controlled to increase by a predetermined amount when the determination result is NG for two consecutive times.

It should be noted that the present invention is not limited to the configurations in the above-described embodiments as long as the characteristic functions of the present invention are not impaired. Also, the configuration may be a combination of the above-described embodiment and a plurality of modifications.

100 Coagulant addition amount adjustment device 101 Raw water inlet automatic valve 102 Raw water inlet 103 Overflow water detection sensor 104 Overflow port 105 Drain port automatic valve 106 Drain port 107 Transparent measurement part 108 Laser sensor 109 Upper opening for cleaning

Claims (14)

A raw water inlet for taking in part of the turbid water after addition of the flocculant;
a laser sensor for measuring turbid water taken in from the raw water inlet;
A control unit that performs processing for adjusting the amount of coagulant to be added to turbid water based on the measurement result of the laser sensor ,
The control unit opens the raw water inlet automatic valve to take in part of the turbid water from the raw water inlet, closes the drain outlet automatic valve, and closes the raw water inlet automatic valve when overflow water is detected by the overflow water detection sensor. is closed, and processing is performed to adjust the amount of coagulant to be added to the turbid water based on the measurement results obtained by measuring with the laser sensor until the preset measurement time elapses, and when the measurement time elapses, the above A coagulant addition amount adjustment device characterized by opening an automatic drain port valve to drain turbid water . In the flocculant addition amount adjusting device according to claim 1,
The control unit compares the measured value of the laser sensor with a preset determination threshold to determine whether the determination result is OK or NG, and if the determination result is NG, muddy water The amount of flocculant added to is controlled to increase by a predetermined amount, and when the judgment result is OK, the amount of flocculant added to turbid water is controlled to decrease by a predetermined amount Addition of a flocculant characterized by quantity regulator. In the flocculant addition amount adjusting device according to claim 2,
A coagulant addition amount adjustment device, wherein the control unit controls the amount of coagulant added to turbid water to increase by a predetermined amount when the determination result is NG for a predetermined number of times in succession. In the flocculant addition amount adjusting device according to claim 2,
The control unit controls the amount of coagulant to be added to the turbid water so as to decrease by a predetermined amount when the judgment result is OK for a predetermined number of times in succession. In the coagulant addition amount adjusting device according to any one of claims 1 to 4,
further comprising a transparent measuring section made of a transparent member,
The coagulant addition amount adjusting device, wherein the laser sensor measures turbid water passing through the transparent measurement section. In the coagulant addition amount adjusting device according to any one of claims 1 to 4,
A coagulant addition amount adjustment device, wherein the measurement time by the laser sensor is calculated in advance according to the coagulation sedimentation speed of the waste water treatment machine to be used. In the coagulant addition amount adjusting device according to any one of claims 1 to 4 ,
The coagulant addition amount adjusting device, wherein the control unit starts the next measurement after a preset standby time has elapsed after the automatic drain valve is opened. A raw water inlet for taking in part of the turbid water after addition of the flocculant;
a laser sensor for measuring turbid water taken in from the raw water inlet;
A coagulant addition amount adjustment method executed by a coagulant addition amount adjustment device including a control unit that performs processing for adjusting the addition amount of coagulant to be added to turbid water based on the measurement result by the laser sensor. hand,
The control unit opens the raw water inlet automatic valve to take in part of the turbid water from the raw water inlet, closes the drain outlet automatic valve, and closes the raw water inlet automatic valve when overflow water is detected by the overflow water detection sensor. is closed, and processing is performed to adjust the amount of coagulant to be added to the turbid water based on the measurement results obtained by measuring with the laser sensor until the preset measurement time elapses, and when the measurement time elapses, the above A method for adjusting the amount of coagulant to be added, which comprises opening an automatic valve for a drain port to drain turbid water. In the method for adjusting the amount of flocculant added according to claim 8 ,
The control unit compares the measured value of the laser sensor with a predetermined determination threshold to determine whether the determination result is OK or NG, and if the determination result is NG, The amount of flocculant added to turbid water is controlled to increase by a predetermined amount, and when the judgment result is OK, the amount of flocculant added to turbid water is controlled to decrease by a predetermined amount. method of adjusting the amount of agent added. In the method for adjusting the amount of flocculant added according to claim 9 ,
A method for adjusting the amount of coagulant to be added, wherein the control unit controls the amount of coagulant to be added to turbid water to increase by a predetermined amount when the determination result is NG for a predetermined number of times in succession. In the method for adjusting the amount of flocculant added according to claim 9 ,
A method for adjusting the amount of coagulant to be added, wherein the control unit controls the amount of the coagulant to be added to the turbid water so as to decrease by a predetermined amount when the judgment result is OK for a predetermined number of times in succession. In the method for adjusting the amount of coagulant added according to any one of claims 8 to 11 ,
A method for adjusting the amount of coagulant to be added, wherein the laser sensor measures turbid water passing through a transparent measuring section made of a transparent member. In the method for adjusting the amount of coagulant added according to any one of claims 8 to 11 ,
A method for adjusting the amount of coagulant to be added, wherein the measurement time by the laser sensor is calculated in advance according to the coagulation sedimentation speed of the waste water treatment machine to be used. In the method for adjusting the amount of coagulant added according to any one of claims 8 to 11 ,
A method for adjusting the amount of coagulant to be added, wherein the control unit starts the next measurement after a preset waiting time has passed after opening the automatic drain valve.

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