Flocculation control device, sludge treatment equipment, sludge coagulation equipment, sludge thickening equipment, flocculation control method, and program

Abstract

To provide a floc state control device, a sludge treatment facility, a sludge coagulation facility, a sludge concentration facility, a floc state control method, and a program, that can easily determine a rotation speed of a stirrer according to a sludge treatment condition and appropriately control a floc state.SOLUTION: A floc state control device comprises: a rotation speed determination part that determines a rotation speed of an agitator that stirs sludge using a determination method that determines the rotation speed according to a processing condition for the sludge; a chemical injection rate control part that controls a chemical injection rate of the flocculant added to the sludge in order to bring flocs of the sludge stirred by the agitator operating at the determined rotation speed into an appropriate state using a coagulant; a rotation speed control part that controls the rotation speed after controlling the chemical injection rate in order to bring the flocs into the appropriate state; and a correction part that corrects the determination method based on the rotation speed when a state of a floc reaches the appropriate state by controlling the rotation speed.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a floc state control device, a sludge treatment facility, a sludge aggregation facility, a sludge thickening facility, a floc state control method, and a program.

Background Art

[0002] Solid-liquid separation devices are used in facilities such as water treatment plants for the purpose of concentrating or dewatering treated substances such as sludge. As such a solid-liquid separation device, for example, there is a concentration device that supplies a treated substance to which a flocculant is added into a cylindrical filtration screen, rotates a screw disposed within the filtration screen to filter the treated substance, and discharges the filtrate. In devices that perform processing on treated substances such as solid-liquid separation devices, the state of the treated substance greatly affects the processing performance. The state of the treated substance is, for example, the state of aggregated sludge (e.g., flocs). Therefore, various techniques have been proposed to appropriately control the state of the treated substance in order to enhance the processing performance of the device.

[0003] For example, Patent Document 1 below discloses a technique for controlling the state of flocs by evaluating the state of flocs based on an image of the flocs passing through a sludge stock solution supply pipe that exits an aggregation mixing tank, and controlling the injection amount of the flocculant and the rotational speed of a stirrer that stirs the sludge and the flocculant according to the evaluation result.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The rotation speed of the agitator, which is set before controlling the rotation speed according to the state of the floc as disclosed in the above-mentioned Patent Document 1, is determined by a person based on empirical rules and taking into consideration the sludge treatment conditions. However, sludge treatment conditions can change depending on the type of sludge being treated. Furthermore, sludge treatment conditions are diverse, including the amount of sludge to be treated, the mixing ratio of the sludge, the temperature of the sludge, and the concentration of the sludge. Therefore, it was difficult for a person to determine the optimal rotation speed while considering all the sludge treatment conditions each time they changed.

[0006] In view of the above-mentioned problems, the object of the present invention is to provide a floc state control device, a sludge treatment facility, a sludge flocculation facility, a sludge thickening facility, a floc state control method, and a program that can easily determine the rotation speed of a stirrer according to the sludge treatment conditions and appropriately control the state of the flocs. [Means for solving the problem]

[0007] To solve the above-mentioned problems, a floc state control device according to one aspect of the present invention controls the rotation speed of a stirrer that agitates sludge, Using information showing the relationship between the sludge treatment conditions and the rotation speed The rotation speed determination unit, A coagulated sludge image acquisition unit acquires an image of the coagulated sludge, which contains flocs obtained by coagulating the sludge with a coagulant after it has been stirred by the agitator operating at the determined rotational speed, in a coagulation mixing tank to which the sludge is transported from the agitator; an analysis unit analyzes the degree of gaps between multiple flocs present in the evaluation target area of ​​the coagulated sludge image and evaluates the chemical injection rate of the coagulant or the rotational speed based on the analysis results; and adjusts the degree of gaps to a target degree according to the evaluation result of the chemical injection rate. before Recording medication A drug injection rate control unit that controls the injection rate, before After controlling the drug injection rate The degree of the gap becomes the target degree. A rotation speed control unit that controls the rotation speed, and by controlling the rotation speed The degree of the aforementioned gap is the target degree. Based on the rotational speed at that time, information It comprises a correction unit that corrects the error, The processing conditions are the amount of sludge to be processed, the mixing ratio of the sludge, the temperature of the sludge, or the concentration of the sludge; the information showing the relationship between the processing conditions of the sludge and the rotation speed is a relational expression or a table; the degree of voids indicates a numerical value relating to the size of the voids and the number of voids; the chemical injection rate is the addition ratio of the coagulant, and is the ratio of the solid weight of the coagulant to the solid weight of the sludge. .

[0008] A sludge treatment facility according to one aspect of the present invention includes a flocculation control device.

[0009] A sludge flocculation facility according to one aspect of the present invention is equipped with a flocculation state control device.

[0010] A sludge thickening facility according to one aspect of the present invention is equipped with a flocculation control device.

[0011] The floc state control method according to one aspect of the present invention includes a rotation speed determination unit that determines the rotation speed of a stirrer for stirring sludge, Using information showing the relationship between the sludge treatment conditions and the rotation speed a rotation speed determination process for determination, A coagulated sludge image acquisition process in which a coagulated sludge image acquisition unit acquires an image of coagulated sludge containing flocs obtained by coagulating the sludge, which has been stirred by the agitator operating at the determined rotation speed, in a coagulation mixing tank to which the sludge is transported from the agitator; and an analysis process in which an analysis unit analyzes the degree of gaps between multiple flocs present in the evaluation target area of ​​the coagulated sludge image and evaluates the chemical injection rate of the coagulant or the rotation speed based on the analysis results. a chemical injection rate control unit, Depending on the evaluation results of the drug injection rate, the degree of the gap will be adjusted to the target degree. the Recording medication chemical injection rate control process for controlling the injection rate, and a rotation speed control unit ,before after controlling the chemical injection rate The degree of the gap becomes the target degree. a rotation speed control process for controlling the rotation speed, and a correction unit, based on the rotation speed when the The degree of the aforementioned gap is the target degree. is achieved by the control of the rotation speed, information corrects the The processing conditions are the amount of sludge to be processed, the mixing ratio of the sludge, the temperature of the sludge, or the concentration of the sludge; the information showing the relationship between the processing conditions of the sludge and the rotation speed is a relational expression or a table; the degree of voids indicates a numerical value relating to the size of the voids and the number of voids; the chemical injection rate is the addition ratio of the coagulant, and is the ratio of the solid weight of the coagulant to the solid weight of the sludge. .

[0012] A program according to one aspect of the present invention causes a computer to function as a rotation speed determination means for determining the rotation speed of a stirrer for stirring sludge, Using information showing the relationship between the sludge treatment conditions and the rotation speed a rotation speed determination means for determination, A means for acquiring a coagulated sludge image of the coagulated sludge containing flocs obtained by coagulating the sludge, which has been stirred by the agitator operating at the determined rotational speed, with a coagulant, in a coagulation mixing tank to which the sludge is transported from the agitator; an analysis means for analyzing the degree of gaps between multiple flocs present in the evaluation target area of ​​the coagulated sludge image and evaluating the chemical injection rate of the coagulant or the rotational speed based on the analysis results; and adjusting the degree of gaps to a target degree according to the evaluation result of the chemical injection rate. the Recording medication chemical injection rate control means for controlling the injection rate, before after controlling the chemical injection rate The degree of the gap becomes the target degree. a rotation speed control means for controlling the rotation speed, and a correction means for correcting the The degree of the aforementioned gap is the target degree. based on the rotation speed when the information is achieved by the control of the rotation speed, The processing conditions are the amount of sludge to be processed, the mixing ratio of the sludge, the temperature of the sludge, or the concentration of the sludge; the information showing the relationship between the processing conditions of the sludge and the rotation speed is a relational expression or a table; the degree of voids indicates a numerical value relating to the size of the voids and the number of voids; the chemical injection rate is the addition ratio of the coagulant, and is the ratio of the solid weight of the coagulant to the solid weight of the sludge. .

Advantages of the Invention

[0013] According to the present invention, it is possible to easily determine the rotation speed of the stirrer according to the sludge treatment conditions and appropriately control the state of the floc.

Brief Description of the Drawings

[0014] [Figure 1] It is a diagram showing an example of the configuration of a sludge treatment facility according to an embodiment of the present invention.<000009o> [Figure 2] It is a diagram showing an example of the functional configuration of a PC according to an embodiment of the present invention. [Figure 3] It is a diagram showing an example of a flocculated sludge image according to an embodiment of the present invention. [Figure 4] It is a diagram showing an example of a flocculated sludge image according to an embodiment of the present invention. [Figure 5] It is a diagram showing an example of an aggregated sludge image according to an embodiment of the present invention. [Figure 6] It is a diagram showing an example of a histogram according to an embodiment of the present invention. [Figure 7] It is a diagram showing an example of a histogram according to an embodiment of the present invention. [Figure 8] It is a diagram showing an example of a histogram according to an embodiment of the present invention. [Figure 9] It is a diagram showing an example of the relationship between the chemical injection rate of a flocculant and the gap area according to an embodiment of the present invention. [Figure 10] It is a diagram showing an example of the relationship between the gap area and the heating efficiency according to an embodiment of the present invention. [Figure 11] It is a flowchart showing an example of the processing flow in a PC according to an embodiment of the present invention. [Figure 12] It is a flowchart showing an example of the detailed processing flow in the analysis process of the degree of gaps according to an embodiment of the present invention. [Figure 13] It is a diagram showing a specific example according to an embodiment of the present invention.

Mode for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0016] <1. Configuration of Sludge Treatment Equipment> First, referring to FIG. 1, the configuration of the sludge treatment equipment according to the present embodiment will be described. FIG. \alpha is a diagram showing an example of the configuration of the sludge treatment equipment according to an embodiment of the present invention.

[0017] Note: In the above translation, \(\alpha\) should be replaced with the actual figure number mentioned in the original text (it seems there is a reference to "Figure 1" in the original text that should be used instead of \(\alpha\) in a more accurate translation). Also, the <0000xxx> tags are left unchanged as per the requirement.As shown in Figure 1, the sludge treatment equipment of this embodiment includes, for example, a coagulation and mixing tank 1, a thickener 2, a dewatering machine 3, a camera 10, a PC (Personal Computer) 20, and a PLC (Programmable Logic Controller) 30. The sludge treatment equipment includes a sludge coagulation unit and a sludge thickening unit. The sludge coagulation unit includes, for example, a coagulation and mixing tank 1, a camera 10, a PC 20, and a PLC 30. The sludge thickening unit includes, for example, a coagulation and mixing tank 1, a thickener 2, a camera 10, a PC 20, and a PLC 30.

[0018] (1) Coagulation mixing tank 1 The coagulation and mixing tank 1 is a device that coagulates sludge A, such as mixed raw sludge generated and supplied from a sewage treatment plant, by adding a coagulant B. As shown in Figure 1, sludge A is supplied to the coagulation and mixing tank 1 from a high-speed mixer 1A (an example of a stirrer for agitating sludge). A coagulant B (for example, a polymer coagulant) is supplied to the high-speed mixer 1A by a pump 1B and added to and mixed with the sludge A. The high-speed mixer 1A has a rotating shaft 1a along its central axis to which stirring blades 1b are attached, and a motor 1c is provided at the top. In the high-speed mixer 1A, the motor 1c rotates the rotating shaft 1a and stirring blades 1b, stirring and mixing the sludge A and coagulant B. The coagulation and mixing tank 1 includes a bottomed cylindrical coagulation tank 1C with a vertically extending central axis into which sludge A mixed with coagulant B is supplied from the bottom and held. The coagulation tank 1C is equipped with a stirring means 1D (an example of a stirrer for stirring sludge) in which stirring blades 1e are attached to a rotating shaft 1d along the central axis of the coagulation tank 1C, and the rotating shaft 1d and stirring blades 1e are rotated by a motor 1f provided at the top of the coagulation tank 1C, thereby stirring and mixing the sludge A and coagulant B. The coagulated sludge C, which contains flocs that have been stirred and mixed with coagulant B by this stirring means 1D, is withdrawn from the top of the coagulation tank 1C and supplied to the thickener 2.

[0019] (2) Concentrator 2 The thickener 2 is equipment for thickening the flocculated sludge C, which has been flocculated to a certain extent by the flocculation and mixing tank 1. The thickener 2 in this embodiment is a vertical filtration thickener and is equipped with a bottomed cylindrical thickening tank 2A ​​having a central axis extending vertically, similar to the flocculation tank 1C, which holds the flocculated sludge C supplied from the flocculation and mixing tank 1. The flocculated sludge C is supplied into the thickening tank 2A ​​from the top of the tank. However, the body of the thickening tank 2A ​​is made of a thickening filtration screen 2a formed of wedge wire or perforated metal, and the outer circumference of this thickening filtration screen 2a is a jacket-shaped filtrate chamber 2b.

[0020] Furthermore, the thickening tank 2A ​​is provided with a conveying means 2B that transports the flocculated sludge C by rotating the rotating shaft 2c and the screw 2d with a motor 2e located at the top of the thickening tank 2A. The flocculated sludge C supplied from the top of the thickening tank 2A ​​is transported downward by this conveying means 2B, and while the water is separated and the sludge is concentrated by the thickening filtration screen 2a, it is drawn out from the bottom of the thickening tank 2A ​​and supplied to the thickened sludge supply passage 4 as concentrated sludge D.

[0021] Furthermore, the bottoms of the thickening tank 2A ​​and the coagulation tank 1C are formed in a frustoconical shape that narrows in diameter towards the bottom. In addition, the water separated from the coagulated sludge C by the thickening filtration screen 2a is collected in the filtrate chamber 2b and treated as return water E.

[0022] Furthermore, in this embodiment, concentrated hot water F, having a temperature in the range of 50°C to less than 100°C, preferably in the range of 60°C to 90°C, is supplied to the concentrator 2 by pump 2C and mixed with the coagulated sludge C supplied from the coagulation mixing tank 1. The concentrator 2 may be supplied with concentrated hot water F by, for example, a concentrated hot water supply means (not shown), or the wastewater J discharged from the drain pipe 3H of the dewatering machine 3 may be supplied as concentrated hot water F.

[0023] In this configuration, the rotating shaft 2c of the conveying means 2B of the concentrator 2 is a hollow cylindrical shape, and numerous through holes are formed in the cylindrical wall of the rotating shaft 2c. The concentrated hot water F is supplied into the rotating shaft 2c from the lower end of the rotating shaft 2c and ejected from the through holes, and is supplied to the coagulated sludge C that is supplied from the coagulation mixing tank 1 into the concentrator 2A and held there, where it is mixed. As a result, in this embodiment, the coagulated sludge C is heated in the concentrator 2, the proteins are thermally denatured, the retained water is separated and discharged as return water E together with the concentrated hot water F, and the concentrated sludge D is concentrated to a predetermined concentration.

[0024] The concentrated sludge supply channel 4, to which the concentrated sludge D is supplied, is equipped with a pump 4A that sends the concentrated sludge D to the dewatering machine 3, and a high-speed mixer 4B is provided between the pump 4A and the dewatering machine 3. A flocculant G, such as an inorganic flocculant like polyferric sulfate (PFS) or a polymer flocculant, is supplied to the high-speed mixer 4B by a pump 4C and added to and mixed with the concentrated sludge D.

[0025] (3) Dehydrator 3 The dewatering machine 3 is equipment for dewatering concentrated sludge D, which has been concentrated by the concentrator 2 and to which a coagulant G has been added and mixed. In the dewatering machine 3, a filtration screen 3B for filtering the concentrated sludge D is arranged inside the casing 3A, and the concentrated sludge D is supplied to the first space 3A1, one of the multiple spaces inside the casing 3A separated by this filtration screen 3B. The dewatering machine 3 in this embodiment is a vertical screw press and is equipped with an internal filtration screen 3a, which is a second filtration screen 3B, arranged inside the casing 3A in a cylindrical or conical shape centered on an axis extending vertically in the same axis as the casing 3A. The dewatering machine 3 is also equipped with an external filtration screen 3b, which is arranged inside the casing 3A at a distance from the internal filtration screen 3a, in a cylindrical or conical shape coaxial with the internal filtration screen 3a. Furthermore, the dewatering machine 3 is equipped with a ribbon screw 3d that is spirally twisted around the axis and housed between the inner filter screen 3a and the outer filter screen 3b, and is rotated relative to the inner filter screen 3a and the outer filter screen 3b around the axis by a motor 3c.

[0026] The space between the inner filtration screen 3a and the outer filtration screen 3b is designated as the first space 3A1, to which concentrated sludge D is supplied. The space inside the inner filtration screen 3a and the space inside the casing 3A outside the outer filtration screen 3b are designated as the second space 3A2. Dewatered hot water H, with a temperature in the range of 50°C to less than 100°C, preferably 60°C to 90°C, is supplied to this second space 3A2 by a pump 3P from a dewatered hot water supply means (not shown). The inner filtration screen 3a and the outer filtration screen 3b are also formed from wedge wire, perforated metal, etc.

[0027] The casing 3A is a bottomed cylindrical shape centered on the above axis. The concentrated sludge D is supplied from the bottom of the casing 3A to the first space 3A1 via a supply pipe 3f connected to an annular connecting plate 3e that connects the bottoms of the inner filtration screen 3a and the outer filtration screen 3b. The supplied concentrated sludge D is transported upward by the relative rotation of the ribbon screw 3d, and water is separated by the inner filtration screen 3a and the outer filtration screen 3b.

[0028] Furthermore, a ring-shaped substrate 3C is disposed in the upper part of the casing 3A, and the outer filter screen 3b is attached and fixed to the inner circumference of this substrate 3C. In addition, a lid 3D is disposed in the upper opening of the casing 3A above the substrate 3C, and the inner filter screen 3a is attached and fixed to this lid 3D. The motor 3c is positioned on this lid 3D and rotates the ribbon screw 3d via a cylindrical screw support that covers the upper part of the inner filter screen 3a. In this embodiment, the inner filter screen 3a and the outer filter screen 3b are fixed to the casing and the ribbon screw 3d is rotated by the motor 3c. However, the ribbon screw 3d may be fixed and the inner filter screen 3a and the outer filter screen 3b may be rotated, or the ribbon screw 3d and the inner filter screen 3a and the outer filter screen 3b may be rotated in opposite directions.

[0029] Furthermore, the upper space within the casing 3A between the substrate 3C and the lid 3D is designated as the discharge chamber 3E, and the annular upper opening of the first space 3A1 in this discharge chamber 3E is designated as the discharge port 3F. A compression ring 3G having a frustoconical outer surface centered on the aforementioned axis that extends upward as it approaches the outer circumference is disposed at this discharge port 3F. The dewatered sludge I, which has been separated from the concentrated sludge D as it is transported upward through the first space 3A1 by the ribbon screw 3d, flows out of the discharge port 3F into the discharge chamber 3E while being compressed by the compression ring 3G and is discharged.

[0030] In this embodiment, the dewatered hot water H is also supplied from the bottom of the casing 3A to the second space 3A2 inside the casing 3A. The dewatered hot water H supplied to the second space 3A2 heats the concentrated sludge D in the first space 3A1, causing the proteins in the concentrated sludge D to denature, separating the water that had been retained. This water is then filtered by the internal filtration screen 3a and the external filtration screen 3b, and together with the dewatered hot water H that has been cooled by heating the concentrated sludge D, it is discharged as wastewater J from the drain pipe 3H rising from the second space 3A2.

[0031] (4) Camera 10 Camera 10 captures images (still or moving images) of the flocculated sludge C, which contains flocs formed when sludge A is flocculated by coagulation agent B in the coagulation tank 1C. Camera 10 is connected to PC 20 for communication and transmits the captured images of the flocculated sludge C (hereinafter also referred to as "flocculated sludge images") to PC 20. The camera 10 can be installed at any location as long as it can image the flocculated sludge C. For example, as shown in Figure 1, the camera 10 is installed at the top of the flocculation tank 1C so as to be able to image the inside of the flocculation tank 1C. However, the location of the camera 10 is not limited to the top of the flocculation tank 1C. The camera 10 may also be installed inside or outside the flocculation tank 1C, as long as it can image the inside of the flocculation tank 1C. Furthermore, the camera 10 may be configured to image the flocculated sludge C when the stirring blades 1e of the stirring means 1D installed in the flocculation tank 1C are at a fixed position. In this case, for example, by taking a picture immediately after the stirring blades 1e of the stirring means 1D installed in the flocculation tank 1C pass the camera 10's shooting position, it becomes easier to capture images of the flocs when they are stationary or moving slowly.

[0032] (5) PC20 PC20 is a device that controls the state of flocs in the flocculated sludge C formed in the flocculation mixing tank 1, and is an example of a flocculation state control device. The flocculation state control device may be, for example, a server device. PC20 receives the flocculated sludge image captured by camera 10 from camera 10. In this embodiment, PC20 determines and controls the state of flocs based on the flocculated sludge image received from camera 10, as an example. For example, PC20 determines the state of flocs by analyzing the degree of gaps between multiple flocs present in the evaluation target area from the flocculated sludge image. The evaluation target area is the area in the flocculated sludge image that is subject to evaluation, and may be the entire area shown in the flocculated sludge image or a part of the area shown in the flocculated sludge image. The degree of gaps is information indicating the extent of gaps present in the evaluation target area. For example, the degree of gaps may be the area of ​​the gap, the diameter (diameter or radius) of the gap, the length (width) of the gap, or the number of gaps.

[0033] The PC20 detects the degree of pores from the obtained coagulated sludge image and performs numerical analysis on this degree of pores to obtain information indicating the characteristic quantities of the pores (hereinafter also referred to as "feature quantity information"). The feature quantity information includes, for example, the average area of ​​the pores, the diameter distribution of the pores, calculated values ​​based on the number of pores, information classifying the degree of pores into classes (hereinafter also referred to as "classification information"), and an image showing the classification information as a histogram (hereinafter also referred to as "histogram image"). The average void area represents the average area of ​​all detected voids. The diameter distribution of gaps can be represented by, for example, the mode diameter, median diameter, and mean diameter. The mode diameter is the diameter (diameter or radius) that appears most frequently among the detected gap diameters. The median diameter is the diameter at which the cumulative frequency of detected gap diameters (diameter or radius) reaches 50%. The mean diameter represents the average of the detected gap diameters (diameter or radius). The calculated value based on the number of gaps is, for example, a value calculated from the number of gaps detected. Classification information is information that divides the degree of gap into multiple classes through numerical analysis, and shows each class and the frequency or ratio corresponding to each class. The frequency corresponding to each class is, for example, the number of features assigned to each class. The ratio corresponding to each class is the ratio of the number of features assigned to each class. A histogram image is a visual representation of a data point where the degree of slack is divided into multiple classes through numerical analysis, and the relationship between each class and the corresponding frequency or ratio is shown. Based on the calculated gap characteristics, PC20 determines the appropriateness of the gap degree and assesses the state of the floc.

[0034] PC20 is connected to PLC30 for communication. PC20 transmits control signals to PLC30 to control the state of the flock. In this embodiment, PC20 transmits, as an example, a signal to control the rotation speed of pump 1B, or a signal to control the rotation speed of motor 1c of high-speed mixer 1A to PLC30. By controlling the rotation speed of pump 1B, the amount of coagulant B supplied from pump 1B to high-speed mixer 1A can be controlled. This allows control of the chemical injection rate of coagulant B added to sludge A. The chemical injection rate is the proportion of coagulant added, which is the weight of solid coagulant relative to the weight of solid sludge. By controlling the rotation speed of the motor 1c of the high-speed mixer 1A, the rotation of the rotating shaft 1a and the stirring blades 1b of the high-speed mixer 1A can be controlled. This allows for control of the mixing ratio of sludge A and coagulant B in the high-speed mixer 1A.

[0035] In another embodiment, the PC20 may transmit a signal to the PLC30 to control the rotation speed of the motor 1f of the stirring means 1D. By controlling the rotation speed of the motor 1f of the stirring means 1D, the rotation of the rotating shaft 1d and the stirring blades 1e of the stirring means 1D can be controlled. This makes it possible to control the degree of mixing of sludge A and coagulant B in the stirring means 1D.

[0036] (6) PLC30 PLC30 is a device that controls the operation of controlled objects. PLC30 controls the operation of controlled objects based on control signals received from PC20. The control signals include, for example, control values ​​that indicate the controlled quantities for each controlled object. The controlled objects are, for example, pump 1B and motor 1c of high-speed mixer 1A. When the controlled object is pump 1B, PLC30 controls the rotational speed of pump 1B based on control signals received from PC20. Similarly, when the controlled object is motor 1c of high-speed mixer 1A, PLC30 controls the rotational speed of motor 1c of high-speed mixer 1A based on control signals received from PC20.

[0037] <2. PC Functional Configuration> The configuration of the sludge treatment facility has been described above with reference to Figure 1. Next, the functional configuration of PC20 will be described with reference to Figures 2 to 10. Figure 2 is a diagram showing an example of the functional configuration of PC20 according to an embodiment of the present invention. As shown in Figure 2, the PC20 consists of an input unit 210, a communication unit 220, a storage unit 230, and an output unit. It comprises a 240 and a control unit 250.

[0038] (1) Input section 210 The input unit 210 has the function of receiving input from the user. The input unit 210 is implemented by an input device such as a keyboard, mouse, or touch panel. This input device may be a device that the PC 20 has built into the hardware, or it may be a device that is externally connected to the PC 20.

[0039] (2) Communications Unit 220 The communication unit 220 has the function of sending and receiving various types of information. For example, the communication unit 220 receives images of coagulated sludge from the camera 10. The communication unit 220 also transmits control signals to the PLC 30.

[0040] (3) Storage section 230 The storage unit 230 has the function of storing various types of information. The storage unit 230 is composed of a storage medium, such as an HDD (Hard Disk Drive), NAS (Network Attached Storage), SSD (Solid State Drive), flash memory, EEPROM (Electrically Erasable Programmable Read Only Memory), RAM (Random Access read / write Memory), ROM (Read Only Memory), or any combination of these storage media.

[0041] (4) Output section 240 The output unit 240 has the function of outputting various types of information. The output unit 240 is implemented by, for example, a display device such as a display. This display device may be a device that the PC 20 has pre-installed as hardware, or it may be a device that is externally connected to the PC 20.

[0042] (5) Control unit 250 The control unit 250 has the function of controlling the overall operation of the PC 20. The control unit 250 is implemented, for example, by causing the CPU (Central Processing Unit) that the PC 20 has as hardware to execute a program. As shown in Figure 2, the control unit 250 includes a coagulated sludge image acquisition unit 251, an image selection unit 252, a region determination unit 253, an analysis unit 254, a chemical injection rate control unit 255, a rotation speed determination unit 256, a rotation speed control unit 257, and a correction unit 258.

[0043] (5-1) Coagulated sludge image acquisition unit 251 The agglomerated sludge image acquisition unit 251 has the function of acquiring agglomerated sludge images. For example, the agglomerated sludge image acquisition unit 251 acquires the agglomerated sludge images that the camera 10 captures and transmits to the PC 20, and the communication unit 220 of the PC 20 receives and acquires the agglomerated sludge images.

[0044] Here, with reference to Figures 3 to 5, the relationship between the state of the flocs and the degree of voids between the flocs will be explained. Figures 3 to 5 show examples of aggregated sludge images. As an example, Figures 3 to 5 show an example where the degree of voids is the area of ​​the voids, and the feature quantity is the average area of ​​the voids.

[0045] Figure 3 shows an image 40 of flocculated sludge where the average area of ​​each void is 150. The voids present in the flocculated sludge shown in image 40 are, for example, voids 41. Figure 4 shows an image 50 of flocculated sludge where the average area of ​​each void is 600. The voids present in the flocculated sludge shown in image 50 are, for example, voids 51. Figure 5 shows an image 60 of flocculated sludge where the average area of ​​each void is 1000. The voids present in the flocculated sludge shown in image 60 are, for example, voids 61.

[0046] In Figures 3 to 5, the amount of coagulant injected increases in the order of coagulated sludge image 40, coagulated sludge image 50, and coagulated sludge image 60. Comparing coagulated sludge image 40, coagulated sludge image 50, and coagulated sludge image 60, it can be seen that increasing the amount of coagulant injected increases the average area of ​​each pore, and decreasing the amount of coagulant injected decreases the average area of ​​each pore. From this, it is possible to determine the quality of the flocs based on the area of ​​the pores (hereinafter also referred to as "pore area") rather than the area of ​​the flocs themselves. Furthermore, Figures 3 to 5 show that, regarding the diameter of the pores, increasing the amount of flocculant injected increases the diameter of each pore, while decreasing the amount of flocculant injected decreases the diameter of each pore. Regarding the number of pores, increasing the amount of flocculant injected decreases the number of pores, while decreasing the amount of flocculant injected increases the number of pores. Thus, it is also possible to determine the quality of the flocs based on the diameter of the pores (hereinafter also referred to as "pore diameter") or the number of pores (hereinafter also referred to as "pore number") rather than the diameter or number of flocs. When flocs overlap with other flocs, it is impossible to accurately calculate the degree of flocs (area, diameter, number, etc.). Using inaccurate floc degrees makes it impossible to accurately understand the state of the flocs. On the other hand, the degree of gaps is not affected by floc overlap, so the degree of each individual gap can be calculated with high accuracy. Therefore, by using the degree of gaps instead of the degree of flocs, it is possible to understand and control the state of the flocs with greater accuracy.

[0047] (5-2) Image selection unit 252 The image selection unit 252 has the function of selecting an image more suitable for controlling the state of flocs from the coagulated sludge images acquired by the coagulated sludge image acquisition unit 251. For example, the image selection unit 252 performs image processing on the coagulated sludge images acquired by the coagulated sludge image acquisition unit 251 to detect the velocity vectors of the flocs using optical flow (OF). Then, the image selection unit 252 selects a coagulated sludge image according to the detection result of the floc velocity vectors by optical flow.

[0048] Specifically, the image selection unit 252 uses optical flow to detect the velocity vectors (i.e., the movement of the flocs) of the flocs from the flocculated sludge images (multiple still or moving images) of the flocculated sludge inside the flocculated mixing tank 1 acquired by the flocculated sludge image acquisition unit 251, and acquires a flocculated sludge image when the vector value of the detected floc velocity vector falls below a predetermined threshold. The vector value is, for example, the sum of the x or y components of the multiple detected velocity vectors. Alternatively, it may be the magnitude (absolute value) of the velocity vector, or it may be the average value rather than the sum of the x or y components of the velocity vector. Preferably, the predetermined threshold is, for example, a value that allows determination that the flocs inside the flocculated mixing tank 1 are stationary, or a value that allows determination that the movement of the flocs is slow.

[0049] With this configuration, the image selection unit 252 can select and acquire images of flocculated sludge when the flocs are stationary or when the flocs are moving slowly. In other words, the image selection unit 252 can exclude images of flocculated sludge that are fluid and unclear due to the stirring effect in the flocculation mixing tank 1. As a result, the PC20 can use agglomerated sludge images in which the flocs are clearer when controlling the state of the flocs, thereby improving the accuracy of floc state control compared to when using agglomerated sludge images in which the flocs are not clear.

[0050] (5-3) Area determination section 253 The region determination unit 253 has the function of determining the regions of gaps and regions other than gaps in the evaluation target region based on the coagulated sludge image. For example, the region determination unit 253 uses a machine learning model to determine the regions of gaps and regions other than gaps in the evaluation target region of the coagulated sludge image acquired by the image selection unit 252. This machine learning model is a trained model that has learned the relationship between the regions of gaps and regions other than gaps in the evaluation target region of the coagulated sludge image.

[0051] The machine learning model used by the region determination unit 253 is a pre-trained model that uses semantic segmentation (SS) to determine whether each pixel in the input coagulated sludge image is in a void region or a non-void region. This pre-trained model uses, for example, images in which a person has previously colored "void regions" and "non-void regions" with different colors as training data. This model is created by training a neural network model that can classify "void regions" and "non-void regions" from the original image in the same way as the training data, using machine learning techniques, and automatically extracting features for classification.

[0052] The region determination unit 253 receives the coagulated sludge image acquired by the image selection unit 252 as input to a trained model that has been machine-learned using semantic segmentation. The trained model outputs the result of classifying each pixel of the input coagulated sludge image into either the "interstitial region" or the "region other than the interstitial region". The region determination unit 253 acquires the result output by the trained model as the determination result.

[0053] The region determination unit 253 may classify each pixel of the coagulated sludge image into either "interstitial regions" or "regions other than interstitial regions" by image processing such as binarization, instead of using the pre-trained model described above. The region determination unit 253 may also perform preprocessing on the coagulated sludge image using a Gaussian filter.

[0054] (5-4) Analysis Department 254 The analysis unit 254 has a function to evaluate the chemical injection rate or rotation speed based on the coagulated sludge image. When evaluating the chemical injection rate after the sludge has been agitated at a rotation speed determined by the rotation speed determination unit 256 (described later), the analysis unit 254 evaluates the chemical injection rate based on the coagulated sludge image acquired after the sludge has been agitated at this rotation speed. When evaluating the chemical injection rate after it has been controlled by the chemical injection rate control unit 255 (described later), the analysis unit 254 evaluates the chemical injection rate based on the coagulated sludge image acquired after the chemical injection rate control. When evaluating the rotation speed after it has been controlled by the rotation speed control unit 257 (described later), the analysis unit 254 evaluates the rotation speed based on the coagulated sludge image acquired after the rotation speed control. Specifically, the analysis unit 254 evaluates the chemical injection rate and rotation speed based on the degree of voids between multiple flocs present in the evaluation area of ​​the coagulated sludge image. In the evaluation, the analysis unit 254 detects the degree of voids from the coagulated sludge image and determines whether this degree of voids is appropriate. If the degree of voids is appropriate, the flocs are in an appropriate state, and the analysis unit 254 evaluates that the chemical injection rate or rotation speed at that time is appropriate. On the other hand, if the degree of voids is not appropriate, the flocs are not in an appropriate state, and the analysis unit 254 evaluates that the chemical injection rate or rotation speed at that time is not appropriate.

[0055] More specifically, the analysis unit 254 first analyzes the degree of voids based on the coagulated sludge image. For example, the analysis unit 254 analyzes the degree of voids between multiple flocs present in the evaluation area based on the coagulated sludge image acquired by the image selection unit 252. Specifically, the analysis unit 254 analyzes the degree of voids in the areas determined to be void areas in the coagulated sludge image based on the determination results acquired by the area determination unit 253. As an example, the analysis unit 254 detects and analyzes the size of the void area, the size of the void diameter (diameter or radius), the number of voids, etc. Furthermore, if multiple gaps are consecutive, the analysis unit 254 treats the multiple gaps as a single gap and detects the degree of the gap.

[0056] The analysis unit 254 analyzes the features of the gap based on the detected gap degree. Based on the gap feature information obtained by numerical analysis of the detected gap degree, the analysis unit 254 determines the appropriateness of the gap degree and outputs the determination result as the analysis result. For example, the analysis unit 254 determines whether the gap degree is appropriate or not using a classification model that classifies the appropriateness of the gap degree based on the gap feature information. This classification model is, for example, a trained model that has learned the relationship between gap feature information and the appropriateness of the gap degree through machine learning. The classification model used by the analysis unit 254 is, for example, a model that has been trained using machine learning such as a support vector machine (SVM) or a random forest. The analysis unit 254 determines whether the degree of the gap is appropriate based on the classification result output by inputting feature information to the classification model.

[0057] For example, suppose the analysis unit 254 inputs the average area of ​​the gap as feature information to the classification model. In this case, the classification model outputs a judgment result indicating whether the degree of the gap (in this case, the area) is appropriate or not, based on the input average area of ​​the gap. Then, the analysis unit 254 determines whether the degree of the gap is appropriate or not based on the judgment result output from the classification model. Furthermore, suppose the analysis unit 254 inputs classification information as feature information into the classification model. In this case, the classification model outputs a judgment result indicating whether the relationship between each class of the degree of slack and the frequency or ratio corresponding to each class is appropriate, based on the input classification information. The analysis unit 254 then determines whether the degree of slack is appropriate based on the judgment result output from the classification model. Furthermore, suppose the analysis unit 254 inputs the histogram image as feature information to the classification model. In this case, the classification model outputs a judgment result indicating whether the relationship between each class of the degree of spacing and the frequency or ratio corresponding to each class is appropriate, based on the shape of the histogram shown by the input histogram image. Then, the analysis unit 254 determines whether the degree of spacing is appropriate based on the judgment result output from the classification model.

[0058] Here, the relationship between classification information and histograms will be explained with reference to Figures 6 to 8. Figures 6 to 8 show examples of histograms according to an embodiment of the present invention. In the graphs (histograms) shown in Figures 6 to 8, the horizontal axis represents the class, and the vertical axis represents the frequency. In Figures 6 to 8, as an example, the degree of the gap is the radius of the gap, the class on the horizontal axis represents the class based on the size of the gap radius, and the frequency on the vertical axis represents the number of radii (i.e., the number of gaps) divided into each class.

[0059] Figure 6 shows a histogram for the case where the number of voids detected in the evaluation area of ​​the flocculated sludge image was 165, the average radius was 9.9, and the top three voids in terms of radius size were 42.6, 33.7, and 33.1. Figure 7 shows a histogram for the case where the number of voids detected in the evaluation area of ​​the flocculated sludge image was 71, the average radius was 10.3, and the top three voids in terms of radius size were 37.0, 34.5, and 33.6. Figure 8 shows a histogram for the case where the number of voids detected in the evaluation area of ​​the flocculated sludge image was 179, the average radius was 7.9, and the top three voids in terms of radius size were 30.4, 25.6, and 21.9.

[0060] Using the histograms and classification models shown in Figures 6 to 8, we performed an actual determination of whether the degree of slack was appropriate. The result was that the degree of slack for the histogram in Figure 6 was deemed appropriate, while the degree of slack for the histograms in Figures 7 and 8 was deemed inappropriate. The histogram in Figure 7 shows 71 gaps, which is significantly fewer than the 165 gaps in the histogram in Figure 6, where the degree of gaps was judged to be appropriate. In the histogram in Figure 8, the average radius is 7.9, which is significantly smaller than the average radius of 9.9 in the histogram in Figure 6, where the degree of gap was judged to be appropriate. The same applies to the sizes of the top three radii. Based on the above, the classification model correctly determines the appropriateness of the degree of gap in the histograms in Figures 7 and 8, assuming that the degree of gap in the histogram in Figure 6 is considered appropriate.

[0061] The analysis unit 254 may also perform numerical analysis on the degree of the gap after excluding at least one degree (e.g., the maximum value) in descending order of degree or at least one degree (e.g., the minimum value) in descending order of degree. If there are multiple consecutive gaps, the analysis unit 254 treats the multiple gaps as a single gap and ranks the degree of the gaps. Then, the analysis unit 254 excludes the higher and lower ranked degree of the gaps and performs numerical analysis on the degree of the gaps. For example, if the degree of the gap is the gap area, the analysis unit 254 excludes the largest and smallest areas from the areas of each of the multiple gaps and then calculates the average area of ​​the gaps as a feature. This allows the analysis unit 254 to reduce errors in judgment caused by noise (e.g., debris and bubbles in the sludge) and fluctuations (e.g., the effects of agitation) when imaging the coagulated sludge.

[0062] The analysis unit 254 may determine whether the degree of the gap is appropriate without using a classification model. For example, the analysis unit 254 may determine whether the degree of voids is appropriate by comparing a threshold value, which serves as a criterion for determining whether the degree of voids is appropriate, with the value indicated by the feature information. This threshold value is set by the user based on, for example, past operating results of the sludge treatment facility. The value indicated by the feature information changes depending on the stirring speed, sludge concentration, etc. As a result, the relationship between the appropriate amount of chemical to be injected (chemical injection rate) and each value also changes. Therefore, the user will conduct actual operation (trial run, etc.) of each device (tank size, stirring device shape, etc.) to determine an appropriate threshold value that results in an appropriate amount of chemical to be injected. Furthermore, the analysis unit 254 may determine whether the degree of voids is appropriate by image recognition processing. Specifically, the analysis unit 254 compares the first coagulated sludge image obtained after controlling the rotation speed with a second coagulated sludge image in which the floc state was previously determined to be appropriate, using image recognition processing. If, as a result of the comparison, the floc state shown in the first coagulated sludge image is close to the floc state shown in the second coagulated sludge image, the analysis unit 254 evaluates that the rotation speed at which the first coagulated sludge image was acquired was appropriate. The analysis unit 254 performs image recognition processing, for example, using a convolutional neural network (CNN).

[0063] If, after evaluating the rotational speed multiple times, no rotational speed is determined to have an appropriate gap, the analysis unit 254 evaluates a more appropriate rotational speed from among the multiple rotational speeds set during control. For example, the analysis unit 254 determines that the appropriate degree of pores is calculated by multiplying the degree of pores showing the maximum value among the degrees of pores shown in each of the multiple coagulated sludge images obtained by controlling the rotation speed multiple times by a predetermined ratio. The analysis unit 254 then evaluates that the rotation speed at which the appropriate degree of pores is obtained, i.e., the rotation speed at which the coagulated sludge image showing the appropriate degree of pores is acquired, is appropriate. The predetermined ratio is calculated by dividing the degree of pores that was determined to be in an appropriate state among the degrees of pores obtained based on multiple coagulated sludge images, based on past experience of controlling the rotation speed multiple times, by the degree of pores showing the maximum value. Assume that no coagulated sludge image showing the appropriate degree of pore size, calculated by multiplying the maximum pore size by a predetermined ratio, has been acquired. In this case, the analysis unit 254 selects from the acquired coagulated sludge images an image showing the degree of pore size closest to the calculated appropriate degree of pore size. The analysis unit 254 may then evaluate whether the rotation speed at which the selected coagulated sludge image was acquired is an appropriate rotation speed. Alternatively, the analysis unit 254 may consider the rotation speed calculated by multiplying the rotation speed at which the coagulated sludge image showing the maximum pore size was acquired by a predetermined ratio as an appropriate rotation speed.

[0064] Furthermore, if, after evaluating the rotation speed multiple times, no rotation speed is determined to have an appropriate degree of pore size, the analysis unit 254 may evaluate a more appropriate rotation speed from among the multiple rotation speeds set during control by performing image recognition processing on multiple coagulated sludge images. In this case, the analysis unit 254 uses, for example, a CNN to compare multiple first coagulated sludge images obtained by controlling the rotation speed multiple times with a second coagulated sludge image in which the floc state was previously determined to be appropriate, using image recognition processing. As a result of the comparison, the analysis unit 254 evaluates that the rotation speed at which the first coagulated sludge image showing a floc state closer to the floc state shown in the second coagulated sludge image was obtained is appropriate.

[0065] Furthermore, if, after evaluating the rotation speed multiple times, no rotation speed is determined to have an appropriate degree of pore size, the analysis unit 254 may use a classification model to evaluate a more appropriate rotation speed from among the multiple rotation speeds set during control. In this case, the analysis unit 254 determines the most appropriate degree of pore size among the various pore sizes based on the feature information in each of the multiple coagulated sludge images obtained by controlling the rotation speed multiple times, and evaluates that the rotation speed that results in the most appropriate degree of pore size is appropriate.

[0066] (5-5) Drug injection rate control unit 255 The chemical injection rate control unit 255 has the function of controlling the chemical injection rate of the coagulant based on the analysis results of the degree of pores. The chemical injection rate control unit 255 controls the chemical injection rate of the coagulant added to the sludge in order to bring the state of the flocs formed by the coagulant on the sludge agitated by the agitator operating at the rotation speed determined by the rotation speed determination unit 256 (described later) to an appropriate state. For example, if the analysis unit 254 determines that the degree of voids is not appropriate, the chemical injection rate control unit 255 controls the chemical injection rate of the coagulant so that the degree of voids becomes the target degree. For example, the chemical injection rate control unit 255 determines the rotation speed of the pump 1B to bring the degree of voids closer to the target degree based on the relationship between the chemical injection rate of the coagulant and the degree of voids. Then, the chemical injection rate control unit 255 transmits a control signal indicating the determined rotation speed of the pump 1B from the communication unit 220 to the PLC 30.

[0067] Here, with reference to Figure 9, the relationship between the chemical injection rate of the coagulant and the degree of voids will be explained. Figure 9 is a diagram showing an example of the relationship between the chemical injection rate of the coagulant and the void area according to an embodiment of the present invention. In Figure 9, as an example, an example is shown in which the degree of voids is the void area. In the graph shown in Figure 9, the horizontal axis represents the chemical injection rate (%) of the coagulant, and the vertical axis represents the void area. As shown in the graph in Figure 9, the void area increases as the drug injection rate increases. However, once the drug injection rate of the coagulant reaches a certain level, the void area decreases if the drug injection rate increases further. This is presumed to be because the flocs disperse due to over-injection, resulting in a smaller floc diameter.

[0068] The chemical injection rate control unit 255 controls the chemical injection rate of the coagulant so that the void area becomes the target area, based on the relationship between the chemical injection rate of the coagulant and the void area as shown in Figure 9. For example, suppose the target area is set to 1300 as shown in Figure 9. If the void area is smaller than 1300, the chemical injection rate control unit 255 can bring the void area closer to the target area by increasing the chemical injection rate of the coagulant. On the other hand, if the void area is larger than 1300, the chemical injection rate control unit 255 may bring the void area closer to the target area by increasing the chemical injection rate of the coagulant, or it may bring the void area closer to the target area by decreasing the chemical injection rate of the coagulant.

[0069] Here, we will explain how to set the target degree. For example, the target degree is set considering the operating efficiency of the equipment located downstream of the coagulation mixing tank 1. As an example, the target degree is set to maximize the operating efficiency. The equipment downstream of the coagulation and mixing tank 1 is, for example, the concentrator 2 shown in Figure 1. If the concentrator 2 is a general-purpose concentrator, the operating efficiency is the concentration efficiency of the concentrator 2. If the concentrator 2 is a heated concentrator, the operating efficiency is the heating efficiency of the concentrator 2. The heating efficiency is calculated, for example, by the following equation (1). Heating efficiency (%) = ΔTact / ΔTide × 100 …(1) In equation (1) above, ΔTact = Concentrated sludge temperature - Original sludge temperature …(2) ΔTide=(T1×Q1+T2×Q2) / (Q1+Q2) …(3) In equation (3) above, T1 is the raw sludge temperature (coagulated sludge temperature), T2 is the hot water temperature, Q1 is the concentrated sludge flow rate, and Q2 is the hot water flow rate.

[0070] Here, with reference to Figure 10, the relationship between the degree of void and heating efficiency will be explained. Figure 10 is a diagram showing an example of the relationship between void area and heating efficiency according to an embodiment of the present invention. In Figure 10, as an example, the degree of void is shown as the void area. In the graph shown in Figure 10, the horizontal axis represents the void area, and the vertical axis represents the heating efficiency (%). The trends in the graphs shown in Figure 10 indicate that heating efficiency tends to increase as the void area increases. However, beyond a certain point in the void area, heating efficiency tends to decrease if the void area increases further. This means that heating efficiency can also decrease if the flocs are too large.

[0071] The chemical injection rate control unit 255 controls the chemical injection rate of the coagulant so that the degree of voids becomes the degree that maximizes heating efficiency, based on the relationship between the degree of voids and heating efficiency as shown in Figure 10. For example, in the example graph shown in Figure 10, heating efficiency is maximized when the void area is around 1250. That is, the target area is set to around 1250. Then, the chemical injection rate control unit 255 controls the chemical injection rate of the coagulant in the same manner as in the example in Figure 9 so that the void area approaches the target area of ​​around 1250.

[0072] Furthermore, the target degree may be set according to the sludge concentration. For example, the chemical injection rate control unit 255 sets a target degree according to the sludge concentration and controls the chemical injection rate of the coagulant so that the degree of pores approaches the target degree. This eliminates the need to adjust the sludge concentration to control the state of the flocs. In other words, the state of the flocs can be controlled without adjusting the sludge concentration by diluting the sludge or adding new equipment.

[0073] (5-6) Rotation speed determination unit 256 The rotation speed determination unit 256 has the function of determining the rotation speed of the agitator that agitates the sludge. The agitator that agitates the sludge, whose rotation speed is determined by the rotation speed determination unit 256, is, for example, a high-speed mixer 1A. In this case, the rotation speed determination unit 256 determines the rotation speed of the motor 1c of the high-speed mixer 1A. However, the example is not limited to this, and the agitator that stirs the sludge, which is the target of rotation speed determination by the rotation speed determination unit 256, may be the coagulation mixing tank 1, and the rotation speed determination unit 256 may determine the rotation speed of the motor 1f of the stirring means 1D.

[0074] The rotation speed determination unit 256 determines the rotation speed according to a determination method that determines the rotation speed according to the sludge treatment conditions. Sludge treatment conditions include, for example, the amount of sludge to be treated, the mixing ratio of the sludge, the temperature of the sludge, and the concentration of the sludge. The determination method involves using information that shows the relationship between sludge treatment conditions and rotation speed to determine the rotation speed. This information is, for example, a relational expression set based on the user's experience or past operating results. Such an expression is, for example, equation (4) below. Y = aX + b …(4) In equation (4) above, X is the treatment condition, Y is the rotation speed, a is the coefficient, and b is the constant term. For example, if the sludge treatment condition is the amount of sludge to be treated, the relationship is an equation that shows the relationship between the amount of sludge to be treated (X) and the rotation speed (Y).

[0075] The relational expression is corrected by the correction unit 258, which will be described later. For example, the relational expression is corrected by the correction unit 258 based on the rotational speed at which the floc state becomes appropriate through rotational speed control. When the relational expression is corrected by the correction unit 258, the rotational speed determination unit 256 uses the corrected relational expression to determine the rotational speed of the agitator that agitates the sludge. The corrected relational expression is, for example, equation (5) below. Y = aX + b + c …(5) In equation (5) above, X is the processing condition, Y is the rotational speed, a is the coefficient, b is the constant term, and c is the correction term. That is, the correction unit 258, which will be described later, calculates the correction term c based on the rotational speed at which the flock state becomes appropriate through rotational speed control and corrects the relational expression.

[0076] The relational expression may be a linear equation, as in equations (4) and (5) above, or it may be a curve, such as a quadratic or cubic function. Furthermore, the information showing the relationship between sludge treatment conditions and rotation speed is not limited to relational formulas; for example, it could be a table showing the relationships between each piece of information.

[0077] (5-7) Rotation speed control unit 257 The rotation speed control unit 257 has a function of controlling the rotation speed. For example, the rotation speed control unit 257 controls the rotation speed of the agitator that agitates the sludge so that the degree of gap becomes a target degree. Specifically, the rotation speed control unit 257 controls the rotation speed of at least one of the following: the rotation speed of the agitator that agitates the sludge sent to the coagulation mixing tank 1, or the rotation speed of the agitator that agitates the coagulated sludge in the coagulation mixing tank 1.

[0078] If the agitator that stirs the sludge sent to the coagulation mixing tank 1 is a high-speed mixer 1A, the rotation speed control unit 257 controls the rotation speed of the motor 1c of the high-speed mixer 1A so that the degree of gap becomes the target degree. In this case, the rotation speed control unit 257 determines the rotation speed of the motor 1c to bring the degree of gap closer to the target degree, based on the relationship between the rotation speed of the motor 1c and the degree of gap. Then, the rotation speed control unit 257 transmits a control signal indicating the determined rotation speed of the motor 1c from the communication unit 220 to the PLC 30.

[0079] If the agitator used to agitate the flocculated sludge in the flocculation mixing tank 1 is the agitator 1D, the rotation speed control unit 257 controls the rotation speed of the motor 1f of the agitator 1D so that the degree of gap becomes the target degree. In this case, the rotation speed control unit 257 determines the rotation speed of the motor 1f to bring the degree of gap closer to the target degree, based on the relationship between the rotation speed of the motor 1f and the degree of gap. The rotation speed control unit 257 then transmits a control signal indicating the determined rotation speed of the motor 1f from the communication unit 220 to the PLC 30.

[0080] In this embodiment, in order to bring the gap degree closer to the target degree, control by the drug injection rate control unit 255 is prioritized over control by the rotation speed control unit 257. This is because controlling the drug injection rate first is more time-efficient and makes it easier to change the floc state. If the gap degree can be brought closer to the target degree by control by the drug injection rate control unit 255 alone, the rotation speed control unit 257 does not need to perform any control. On the other hand, if the gap degree cannot be brought closer to the target degree by control by the drug injection rate control unit 255 alone, the rotation speed control unit 257 controls the rotation speed.

[0081] The rotational speed control unit 257 controls the rotational speed after the drug injection rate control unit 255 controls the drug injection rate in order to bring the flocs to an appropriate state. For example, if the flocs are not brought to an appropriate state by controlling the drug injection rate control unit 255 alone, the rotational speed control unit 257 fixes the drug injection rate and controls the rotational speed. At this time, the rotational speed control unit 257 tries multiple rotational speeds by increasing and decreasing the rotational speed so that it can determine the most optimal rotational speed from among them. Furthermore, even if the floc condition is appropriate solely through the drug injection rate control by the drug injection rate control unit 255, the rotation speed control unit 257 may periodically fix the drug injection rate and control the rotation speed. For example, the rotation speed control unit 257 may control the rotation speed at predetermined timings, such as after a set period of time such as one day, one week, or one month, or at the change of seasons.

[0082] (5-8) Correction unit 258 The correction unit 258 has a function to correct the determination method based on the rotational speed at which the flock state becomes appropriate through rotational speed control. For example, if the determination method is a method that uses a relational expression, the correction unit 258 calculates a correction term and corrects the relational expression using this correction term.

[0083] As an example, suppose the rotational speed required to process sludge with a processing volume of X1 is calculated as Y1 from equation (4), where the coefficient is a1 and the constant term is b1. Suppose that when the high-speed mixer 1A is operated at this rotational speed Y1, the floc state is not appropriate with only the chemical injection rate control unit 255 controlling the chemical injection rate, so the rotational speed control unit 257 controls the rotational speed. Suppose that as a result of the rotational speed control unit 257 controlling the rotational speed, the floc state becomes appropriate when the rotational speed is Y2. In this case, the correction unit 258 calculates a correction term based on equation (5) described above. Specifically, the correction unit 258 substitutes the known coefficient a1, the constant term b1, the processing volume X1, and the rotational speed Y2 obtained as a result of the control into equation (5) to calculate the correction term c1. Then, the correction unit 258 corrects equation (4) with the calculated correction term c1 to obtain the corrected relationship.

[0084] <3. Processing Flow> The functional configuration of PC20 has been explained above with reference to Figures 2 to 10. Next, the processing flow in PC20 will be explained with reference to Figures 11 and 12.

[0085] (1) Processing flow in PC20 Figure 11 is a flowchart showing an example of the processing flow in PC20 according to an embodiment of the present invention. In Figure 11, as an example, the rotation speed control unit 257 controls the rotation speed of the motor 1c of the high-speed mixer 1A, the method for determining the rotation speed is a method using a relational expression, and the processing condition is the amount of sludge to be processed.

[0086] As shown in Figure 11, first, the rotation speed determination unit 256 of PC20 determines the rotation speed of the motor 1c of the high-speed mixer 1A according to the amount of sludge to be processed using a relational equation (step S101). Next, the analysis unit 254 of PC20 performs an analysis of the degree of the gap (step S102). Details of the analysis of the degree of the gap will be described later. The analysis unit 254 obtains a determination result of whether the degree of the gap is appropriate through the analysis of the degree of the gap.

[0087] Next, the analysis unit 254 evaluates the drug injection rate (step S103). Specifically, based on the result of the determination of the appropriateness of the degree of gap, the analysis unit 254 evaluates that the drug injection rate is appropriate if the degree of gap is appropriate, and evaluates that the drug injection rate is inappropriate if the degree of gap is not appropriate.

[0088] If the chemical injection rate is appropriate (step S104 / YES), the flocculation state is appropriate, so there is no need to control the chemical injection rate. Therefore, PC20 returns to step S102 and repeats the process for the next acquired coagulated sludge image. On the other hand, if the chemical injection rate is inappropriate (step S104 / NO), the flocculation state is inappropriate, so it is necessary to control the chemical injection rate. Therefore, PC20 proceeds to step S105.

[0089] If the process proceeds to step S105, the chemical injection rate control unit 255 of PC20 controls the chemical injection rate of the coagulant (step S105). Specifically, the chemical injection rate control unit 255 controls the chemical injection rate of the coagulant so that the degree of the gap reaches the target degree.

[0090] After controlling the drug injection rate, the analysis unit 254 checks the change in the degree of gap (step S106). The analysis unit 254 determines from the change in the degree of gap whether continuing to control the drug injection rate is effective in controlling the floc state. To make this determination, the analysis unit 254 obtains the degree of gap after controlling the drug injection rate for the most recent few times and calculates multiple changes in the degree of gap as the difference between the degree of gap before controlling the drug injection rate and the degree of gap after controlling the drug injection rate. The analysis unit 254 compares the multiple calculated changes and determines whether the change in the degree of gap due to the control of the drug injection rate has decreased. The determination of whether the change in the degree of gap has decreased is made, for example, by comparing the calculated change with a threshold or by calculating the variance. If the degree of gap change is small (step S106 / YES), controlling the drug injection rate is no longer effective in controlling the state of the floc, and control of the floc state by controlling the rotation speed is necessary. Therefore, PC20 proceeds to step S107. Also, before proceeding to S107, the drug injection rate is fixed to a predetermined value. The drug injection rate to be fixed may be the value of the drug injection rate immediately before, the optimal drug injection rate value from past performance, or a value manually entered by a person. On the other hand, if the degree of void change has not decreased (step S106 / NO), controlling the chemical injection rate is effective in controlling the state of the flocs. Therefore, the rotation speed PC20 returns the process to step S102, and the process is repeated for the next acquired coagulated sludge image.

[0091] If the process proceeds to step S107, the rotation speed control unit 257 controls the rotation speed of the motor 1c of the high-speed mixer 1A (step S107). For example, the rotation speed control unit 257 increases or decreases the current rotation speed by an arbitrary amount. Next, the analysis unit 254 performs an analysis of the degree of the gap (step S108). The process in step S108 is the same as the process in step S102.

[0092] Next, the analysis unit 254 evaluates the rotation speed (step S109). Specifically, based on the result of determining the appropriateness of the gap degree, the analysis unit 254 evaluates that the rotation speed is appropriate if the gap degree is appropriate, and evaluates that the rotation speed is inappropriate if the gap degree is not appropriate.

[0093] If the rotational speed is appropriate (step S110 / YES), the flock state is appropriate, so there is no need to control the rotational speed. Therefore, PC20 proceeds to step S111. On the other hand, if the rotational speed is not appropriate (step S110 / NO), the flock state is not appropriate, so it is necessary to control the rotational speed. Therefore, PC20 returns to step S107 and repeats the rotational speed control and evaluation.

[0094] If the process proceeds to step S111, the correction unit 258 of PC20 corrects the method for determining the rotational speed (step S111). For example, the correction unit 258 calculates a correction term in the relational expression based on the rotational speed determined to be appropriate in step S110, and corrects the relational expression using this correction term. After the correction, PC20 repeats the process from step S101. In the corrected step S101, the rotation speed is determined using the corrected relational expression. This allows the user to determine an appropriate rotation speed according to the changed sludge processing volume (processing conditions) without having to correct the relational expression themselves.

[0095] (2) Detailed processing flow for analyzing the degree of gap Figure 12 is a flowchart showing an example of a detailed processing flow in the analysis process for the degree of gap according to an embodiment of the present invention.

[0096] As shown in Figure 12, first, the agglomerated sludge image acquisition unit 251 of PC20 acquires the agglomerated sludge image received by the communication unit 220 of PC20, which is captured by the camera 10 and transmitted to PC20 (step S201).

[0097] Next, the image selection unit 252 of the PC20 performs image processing on the coagulated sludge image acquired by the coagulated sludge image acquisition unit 251 to detect the velocity vectors of the flocs using optical flow (step S202). After detecting the velocity vectors of the flocs, the image selection unit 252 selects an image of the flocculated sludge according to the detection result of the velocity vectors of the flocs (step S203).

[0098] Next, the region determination unit 253 of PC20 uses a machine learning model to determine which regions are voids and which are not voids in the coagulated sludge image acquired by the image selection unit 252 (step S204).

[0099] Next, the analysis unit 254 of PC20 performs an analysis of the degree of pores (step S205). Specifically, the analysis unit 254 detects the degree of pores in the regions determined to be pore regions in the coagulated sludge image, based on the determination result by the region determination unit 253.

[0100] Next, the analysis unit 254 performs an analysis of the gap's features (step S206). Specifically, the analysis unit 254 obtains feature information indicating the gap's features by performing a numerical analysis on the degree of the gap detected by the analysis.

[0101] Next, the analysis unit 254 performs a determination of the appropriateness of the gap (step S207). For example, the analysis unit 254 inputs the gap feature information obtained by the analysis into a classification model and determines whether the gap is appropriate or not from the determination result output from the classification model. Then, PC20 finishes the analysis process for the degree of the gap.

[0102] <4. Specific Examples> The processing flow in PC20 has been explained above with reference to Figures 11 and 12. Next, a specific example will be explained with reference to Figure 13. Figure 13 is a diagram showing a specific example according to an embodiment of the present invention. In Figure 13, as an example, an example is shown in which the degree of the gap is the gap area.

[0103] Figure 13 shows the measured time-series changes in void area and drug injection rate, as well as the corresponding time-series changes in heating efficiency, when the drug injection rate is controlled so that the void area reaches the target area. The target area is set to 1250 ± 100. As shown in Figure 13, by controlling the drug injection rate so that the gap area was 1250 ± 100, the drug injection rate was in the range of 0.40% to 0.41%, as shown in the results from 14:50 to 15:50, and the heating efficiency remained at a high level with an average of 113%. Furthermore, in an experiment where the drug injection rate was not controlled and was assumed to have decreased to 0.37% due to concentration fluctuations, the void area dropped to approximately 800, as shown in the results from 15:55 to 16:20, and the heating efficiency fell below 100%. Based on the above, it can be said that by controlling the chemical injection rate to maintain an appropriate void area, high heating efficiency can be maintained. Furthermore, by maintaining an appropriate void area, it becomes possible to optimize the amount of chemical injected, enabling safe operation of the concentrator 2 and reducing the amount of chemical injected (reducing costs).

[0104] As described above, the PC20 (flocculation state control device) of this embodiment corrects the method for determining the rotation speed of the agitator that stirs the sludge according to the sludge treatment conditions, based on the rotation speed at which the flocculation state is appropriate. Therefore, even when the treatment conditions change, the PC20 can calculate the rotation speed at which the flocculation state is appropriate and set the rotation speed of the agitator to the calculated rotation speed. As a result, the user does not need to determine the optimal rotation speed considering the sludge treatment conditions based on empirical rules each time the treatment conditions change.

[0105] Therefore, the PC20 according to this embodiment makes it possible to easily determine the rotation speed of the agitator according to the sludge treatment conditions and to appropriately control the state of the flocs.

[0106] Embodiments of the present invention have been described above. Furthermore, some or all of the PC20 in the above-described embodiment may be implemented using a computer. In that case, the program for implementing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be loaded into a computer system and executed. Here, "computer system" includes hardware such as an OS and peripheral devices. Furthermore, "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and storage devices such as hard disks built into a computer system. Moreover, "computer-readable recording medium" may also include those that dynamically hold programs for a short period of time, such as communication lines used when transmitting programs via networks such as the Internet or communication lines such as telephone lines, and those that hold programs for a certain period of time, such as volatile memory inside a computer system that acts as a server or client in such cases. Furthermore, the above-mentioned program may be for implementing some of the functions described above, or it may be a program that can implement the above-mentioned functions in combination with a program already recorded in the computer system, or it may be implemented using a programmable logic device such as an FPGA (Field Programmable Gate Array).

[0107] Although embodiments of this invention have been described in detail above with reference to the drawings, the specific configuration is not limited to those described above, and various design changes can be made without departing from the spirit of this invention.

[0108] (Note 1) A rotation speed determination unit that determines the rotation speed of a stirrer for agitating sludge according to a determination method for determining the rotation speed according to the sludge treatment conditions, A chemical injection rate control unit controls the chemical injection rate of the coagulant added to the sludge in order to bring the state of the flocs formed by the coagulant flocculating the sludge, which has been agitated by the agitator operating at the determined rotational speed, to an appropriate state. To bring the state of the floc to an appropriate condition, a rotation speed control unit controls the rotation speed after controlling the drug injection rate, A correction unit corrects the determination method based on the rotational speed at which the state of the flock becomes appropriate through the control of the rotational speed, A flock state control device equipped with the following:

[0109] (Note 2) The aforementioned processing conditions are the amount of sludge to be processed, The aforementioned determination method is a method for determining the rotation speed using a relational expression that shows the relationship between the amount of sludge to be processed and the rotation speed. The flock state control device described in Appendix 1.

[0110] (Note 3) The rotational speed control unit controls the rotational speed by fixing the drug injection rate if the state of the floc cannot be brought to an appropriate state by controlling only the drug injection rate. A flock state control device as described in Appendix 1 or Appendix 2.

[0111] (Note 4) The rotation speed control unit periodically fixes the drug injection rate and controls the rotation speed. A flock state control device as described in Appendix 1 or Appendix 2.

[0112] (Note 5) A coagulated sludge image acquisition unit acquires a coagulated sludge image of the coagulated sludge containing the flocs in a coagulation mixing tank to which the sludge is transported from the agitator, An analysis unit that evaluates the chemical injection rate or the rotation speed based on the acquired coagulated sludge image, A flock state control device according to any one of the appendices 1 to 4, further comprising:

[0113] (Note 6) The analysis unit evaluates the rotation speed after control based on the degree of gaps between multiple flocs present in the evaluation target area of ​​the flocculated sludge image acquired after the control of the rotation speed. Flock state control device as described in Appendix 5.

[0114] (Note 7) The analysis unit determines that the appropriate degree of pores is calculated by multiplying the degree of pores shown in each of the multiple aggregated sludge images obtained by controlling the rotation speed multiple times by a predetermined ratio, and evaluates that the rotation speed that results in the appropriate degree of pores is appropriate. The flock state control device described in Appendix 6.

[0115] (Note 8) The predetermined ratio is a value calculated by dividing the degree of voids in which the flocculation state is determined to be appropriate, among the multiple degrees of voids obtained based on the multiple coagulated sludge images, by the degree of voids showing the maximum value. The flock state control device described in Appendix 7.

[0116] (Note 9) The analysis unit compares a plurality of first coagulated sludge images obtained by controlling the rotation speed multiple times with a second coagulated sludge image in which the floc state was previously determined to be in an appropriate state, using image recognition processing, and evaluates that the rotation speed is appropriate when the first coagulated sludge image obtained shows a floc state that is closer to the floc state shown in the second coagulated sludge image. The flock state control device described in Appendix 6.

[0117] (Note 10) The analysis unit determines the most appropriate degree of pores among the various pore sizes based on feature information indicating the pore characteristics obtained by numerical analysis of the degree of pores shown in each of the multiple coagulated sludge images obtained by controlling the rotation speed multiple times, and evaluates that the rotation speed that results in the most appropriate degree of pores is appropriate. The flock state control device described in Appendix 6.

[0118] (Note 11) The analysis unit uses a classification model that classifies the appropriateness of the degree of the gap based on the feature information, and determines the most appropriate degree of the gap based on the classification result output by inputting the feature information to the classification model. Flock state control device as described in Appendix 10.

[0119] (Note 12) The analysis unit divides the degree of the gap into multiple classes by numerical analysis, obtains classification information indicating each class and the frequency or ratio corresponding to each class, and inputs the classification information as feature information into the classification model. Flock state control device as described in Appendix 11.

[0120] (Note 13) The analysis unit divides the degree of the gap into multiple classes by numerical analysis, obtains a histogram image showing the relationship between each class and the frequency or ratio corresponding to each class, and inputs the image as feature information into the classification model. Flock state control device as described in Appendix 11.

[0121] (Note 14) A sludge treatment facility equipped with a flocculation control device as described in any one of the appendices 1 to 13.

[0122] (Note 15) A sludge flocculation facility equipped with a flocculation control device described in any one of the appendices 1 to 13.

[0123] (Note 16) A sludge thickening facility equipped with a flocculation control device as described in any one of the appendices 1 to 13. [Explanation of symbols]

[0124] 1...Coagulation and mixing tank, 1a...Rotating shaft, 1A...High-speed mixer, 1b...Agitating blade, 1B...Pump, 1c...Motor, 1C...Coagulation tank, 1d...Rotating shaft, 1D...Agitation means, 1e...Agitating blade, 1f...Motor, 2...Concentrator, 2a...Concentration filtration screen, 2A...Concentration tank, 2b...Filtrate chamber, 2B...Conveying means, 2c...Rotating shaft, 2C...Pump, 2d...Screw, 2e...Motor, 3...Dehydrator, 3a...Internal filtration screen, 3A...Casing, 3A1...First space, 3A2...Second space, 3b...External filtration screen, 3B...Filtration screen, 3c...Motor, 3C...Substrate, 3d...Ribbon screw, 3D...Lid, 3 e...Connecting plate, 3E...Discharge chamber, 3f...Supply pipe, 3F...Discharge port, 3G...Compression ring, 3H...Drain pipe, 3P...Pump, 4...Concentrated sludge supply path, 4A...Pump, 4B...High-speed mixer, 4C...Pump, 10...Camera, 40...Coagulated sludge image, 41...Gap, 50...Coagulated sludge image, 51...Gap, 60...Coagulated sludge image, 61...Gap, 210...Input unit, 220...Communication unit, 230...Storage unit, 240...Output unit, 250...Control unit, 251...Coagulated sludge image acquisition unit, 252...Image selection unit, 253...Region determination unit, 254...Analysis unit, 255...Chemical injection rate control unit, 256...Rotation speed determination unit, 257...Rotation speed control unit, 258...Correction unit

Claims

1. A rotation speed determination unit determines the rotation speed of a stirrer that agitates sludge using information showing the relationship between the sludge treatment conditions and the rotation speed, A coagulated sludge image acquisition unit acquires an image of the coagulated sludge, which contains flocs obtained by coagulating the sludge, which has been agitated by the agitator operating at the determined rotational speed, with a coagulating agent, in a coagulation mixing tank to which the sludge is transported from the agitator. An analysis unit analyzes the degree of gaps between multiple flocs present in the evaluation area of ​​the coagulated sludge image and evaluates the chemical injection rate of the coagulant or the rotation speed based on the analysis results. A drug injection rate control unit controls the drug injection rate so that the degree of the gap becomes the target degree according to the evaluation result of the drug injection rate, A rotation speed control unit controls the rotation speed after the control of the drug injection rate so that the degree of the gap becomes the target degree, A correction unit corrects the information based on the rotational speed at which the degree of the gap reaches the target degree through the control of the rotational speed, Equipped with, The aforementioned processing conditions include the amount of sludge to be processed, the mixing ratio of the sludge, the temperature of the sludge, or the concentration of the sludge. The information showing the relationship between the sludge treatment conditions and the rotation speed is in the form of a relational expression or a table. The degree of the gap indicates a numerical value relating to the size of the gap and the number of gaps. The aforementioned chemical injection rate is the addition ratio of the coagulant, and is the ratio of the solid weight of the coagulant to the solid weight of the sludge. Flock state control device.

2. The rotational speed control unit controls the rotational speed by fixing the drug injection rate if the degree of the gap does not reach the target degree by controlling only the drug injection rate. The flock state control device according to claim 1.

3. The rotation speed control unit periodically fixes the drug injection rate and controls the rotation speed. The flock state control device according to claim 1.

4. The analysis unit evaluates the controlled rotation speed based on the degree of the gaps in the coagulated sludge image acquired after the control of the rotation speed. The flock state control device according to claim 1.

5. The analysis unit determines that the appropriate degree of pores is calculated by multiplying the degree of pores shown in each of the multiple aggregated sludge images obtained by controlling the rotation speed multiple times by a predetermined ratio, and evaluates that the rotation speed that results in the appropriate degree of pores is appropriate. The predetermined ratio is a value calculated by dividing the degree of voids that is determined to be the target degree among the multiple degrees of voids obtained based on the multiple coagulated sludge images by the degree of voids that shows the maximum value. The flock state control device according to claim 4.

6. The analysis unit compares a plurality of first agglomerated sludge images obtained by controlling the rotation speed multiple times with a second agglomerated sludge image in which the degree of the gaps was previously determined to be at the target degree, using image recognition processing, and evaluates that the rotation speed is appropriate when the first agglomerated sludge image showing a floc state closer to the floc state shown in the second agglomerated sludge image is obtained. The flock state control device according to claim 4.

7. The analysis unit determines the most appropriate degree of pores among the various pore sizes based on feature information indicating the pore characteristics obtained by numerical analysis of the degree of pores shown in each of the multiple coagulated sludge images obtained by controlling the rotation speed multiple times, and evaluates that the rotation speed that results in the most appropriate degree of pores is appropriate. The characteristic quantity of the gap is a value that changes with respect to the gap depending on the stirring speed and sludge concentration in the coagulation mixing tank. The flock state control device according to claim 4.

8. The analysis unit uses a classification model that classifies the appropriateness of the degree of the gap based on the feature information, and determines the most appropriate degree of the gap based on the classification result output by inputting the feature information to the classification model. The flock state control device according to claim 7.

9. The analysis unit divides the degree of the gap into multiple classes by numerical analysis, obtains classification information indicating each class and the frequency or ratio corresponding to each class, and inputs the classification information as feature information into the classification model. The flock state control device according to claim 8.

10. The analysis unit divides the degree of the gap into multiple classes by numerical analysis, obtains a histogram image showing the relationship between each class and the frequency or ratio corresponding to each class, and inputs the image as feature information into the classification model. The flock state control device according to claim 8.

11. A sludge treatment facility comprising a flocculation control device as described in claim 1.

12. A sludge flocculation apparatus comprising a flocculation state control device as described in claim 1.

13. A sludge thickening facility comprising a flocculation control device as described in claim 1.

14. The rotation speed determination unit determines the rotation speed of the agitator that agitates the sludge using information indicating the relationship between the sludge treatment conditions and the rotation speed, and The coagulated sludge image acquisition process involves a coagulated sludge image acquisition unit that acquires an image of the coagulated sludge, which includes flocs obtained by coagulating the sludge, which has been stirred by the agitator operating at a determined rotation speed, with a coagulating agent, in a coagulation mixing tank to which the sludge is transported from the agitator. The analysis unit analyzes the degree of gaps between multiple flocs present in the evaluation area of ​​the flocculated sludge image, and evaluates the chemical injection rate of the flocculant or the rotation speed based on the analysis results, and A drug injection rate control unit controls the drug injection rate in accordance with the evaluation result of the drug injection rate so that the degree of the gap becomes the target degree, and The rotation speed control unit, after controlling the drug injection rate, performs a rotation speed control process in which it controls the rotation speed so that the degree of the gap becomes the target degree. The correction unit performs a correction process that corrects the information based on the rotational speed at which the degree of the gap becomes the target degree through the control of the rotational speed, Includes, The aforementioned processing conditions include the amount of sludge to be processed, the mixing ratio of the sludge, the temperature of the sludge, or the concentration of the sludge. The information showing the relationship between the sludge treatment conditions and the rotation speed is in the form of a relational expression or a table. The degree of the gap indicates a numerical value relating to the size of the gap and the number of gaps. The aforementioned chemical injection rate is the addition ratio of the coagulant, and is the ratio of the solid weight of the coagulant to the solid weight of the sludge. A method for controlling the flock state.

15. Computers, A rotation speed determination means for determining the rotation speed of a stirrer that agitates sludge using information showing the relationship between the sludge treatment conditions and the rotation speed, A means for acquiring an image of coagulated sludge, which is captured in a coagulation mixing tank to which the coagulated sludge containing flocs obtained by coagulating the sludge, which has been agitated in the agitator operating at the determined rotational speed, is transported from the agitator, and the means for acquiring an image of the coagulated sludge, An analytical means for analyzing the degree of gaps between multiple flocs present in the evaluation area of ​​the coagulated sludge image, and for evaluating the chemical injection rate of the coagulant or the rotation speed based on the analysis results, A drug injection rate control means controls the drug injection rate so that the degree of the gap becomes the target degree according to the evaluation result of the drug injection rate, A rotation speed control means that controls the rotation speed after controlling the drug injection rate so that the degree of the gap becomes the target degree, A correction means for correcting the information based on the rotational speed at which the degree of the gap reaches the target degree through the control of the rotational speed, To make it function as, The aforementioned processing conditions include the amount of sludge to be processed, the mixing ratio of the sludge, the temperature of the sludge, or the concentration of the sludge. The information showing the relationship between the sludge treatment conditions and the rotation speed is in the form of a relational expression or a table. The degree of the gap indicates a numerical value relating to the size of the gap and the number of gaps. The aforementioned chemical injection rate is the addition ratio of the coagulant, and is the ratio of the solid weight of the coagulant to the solid weight of the sludge. program.

Images