Floc state control device, sludge treatment facility, floc state control method, and program

Abstract

To provide a flock state control device, a sludge treatment facility, a flock state control method and a program capable of suitably controlling the state of flocks at a place capable of easily performing imaging from the inside of piping at a latter stage and early performing the adjustment of a flocculant without diluting the concentration of sludge and adding a new device for reducing the overlapping of the flocks.SOLUTION: A flock state control device comprises: a flocculated sludge image acquisition part for acquiring a flocculated sludge image obtained by imaging flocculated sludge including flocks in which sludge is flocculated by a flocculant in a flocculation mixing tank; a gap area acquisition part for acquiring a gap area showing an area of a gap generated between the plurality of flocks based on the acquired flocculated sludge image; and a chemical feed rate control part for controlling the chemical feed rate of the flocculant so that the acquired gap area reaches a target area.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a floc state control device, sludge treatment equipment, 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 objects to be treated such as sludge. As such a solid-liquid separation device, for example, there is a concentration device that supplies an object to be treated with a flocculant added thereto into a cylindrical filtration screen, rotates a screw disposed in the filtration screen to filter the object to be treated, and discharges the filtrate. Generally, increasing the amount of flocculant added tends to promote solid-liquid separation of the object to be treated. In controlling the injection amount of such a flocculant, for example, there is a method of imaging sludge in a flocculation mixing tank or the like and controlling the injection amount of the flocculant according to the formation state of the flocculated sludge (for example, floc) (for example, the area of the floc).

[0003] For example, Patent Document 1 below discloses a technique for photographing flocs of suspended substances in a pipe line exiting a flocculation mixing tank and evaluating the flocculated sludge. In this technique, for example, the suspended substances contained in the raw liquid supply pipe of a dehydrator are imaged, the average area of the flocs for several times or the average area per floc is calculated from the binary image of the flocs shown in the captured image, and the appropriate value of the injection amount of the flocculant is calculated by comparing the average area with a preset reference area of the flocs.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the technology described in Patent Document 1, when the flocs shown in the captured image overlap with other flocs, the area of each floc cannot be accurately calculated. In this case, the injection amount of the flocculant cannot be appropriately calculated, and the state of the flocs cannot be appropriately controlled. In order to reduce the overlap of the flocs, it is conceivable to dilute the sludge concentration, but it is necessary to separately provide a dilution device. Alternatively, in order to reduce the overlap of the flocs shown in the captured image, a television camera is installed in the pipe line of the stock solution, and it is necessary to capture the size of the flocs in a pipe where the overlap of the flocs is small and the flow rate is moderate without pulsation.

[0006] In view of the above problems, an object of the present invention is to easily capture images from the subsequent pipe without diluting the sludge concentration or adding a new device to reduce the overlap of the flocs, and to adjust the flocculant earlier. It is an object of the present invention to provide a floc state control device, a sludge treatment facility, a floc state control method, and a program capable of appropriately controlling the state of flocs at a possible location.

Means for Solving the Problems

[0007] In order to solve the above problems, a floc state control device according to an aspect of the present invention includes a coagulated sludge image acquisition unit that acquires a coagulated sludge image obtained by imaging coagulated sludge including flocs coagulated by a flocculant in a coagulation mixing tank, Using a machine learning model that determines the region of the gaps formed between the plurality of the flocs in the flocculated sludge image and the region other than the region of the gaps, a region determination unit determines the region of the gaps and the region other than the region of the gaps in the acquired flocculated sludge image, and the area of the region determined to be the region of the gaps is calculated as the following A gap area acquisition unit that indicates the area of the gap Calculated as And a chemical injection rate control unit that controls the chemical injection rate of the flocculant so that the acquired gap area becomes a target area. , and the machine learning model is a model that performs machine learning using semantic segmentation to determine whether each pixel of the input flocculated sludge image is in the region of the gaps or in the region other than the region of the gaps It has.

[0008] A sludge treatment facility according to an aspect of the present invention includes a floc state control device.

[0009] A floc state control method according to an aspect of the present invention includes a coagulated sludge image acquisition process in which a coagulated sludge image acquisition unit acquires a coagulated sludge image obtained by imaging coagulated sludge including flocs coagulated by a flocculant in a coagulation mixing tank, The region determination unit uses a machine learning model that determines the region of the gaps formed between the plurality of the flocs in the flocculated sludge image and the region other than the region of the gaps, and determines the region of the gaps and the region other than the region of the gaps in the acquired flocculated sludge image in a region determination process The gap area acquisition unit isThe area of the region determined to be the region of the gaps is calculated as the following The gap area indicating the area of the gap Calculated as It includes a gap area acquisition process of acquiring the gap area, and a chemical injection rate control process in which the chemical injection rate control unit controls the chemical injection rate of the flocculant so that the acquired gap area becomes the target area. , and the machine learning model is a model that performs machine learning using semantic segmentation to determine whether each pixel of the input flocculated sludge image is in the region of the gaps or in the region other than the region of the gaps .

[0010] A program according to an aspect of the present invention causes a computer to function as a flocculated sludge image acquisition means for acquiring a flocculated sludge image obtained by imaging flocculated sludge containing flocs in which sludge is flocculated by a flocculant in a flocculation mixing tank, Using a machine learning model that determines the region of the gaps formed between the plurality of the flocs in the flocculated sludge image and the region other than the region of the gaps, a region determination means determines the region of the gaps and the region other than the region of the gaps in the acquired flocculated sludge image, and the area of the region determined to be the region of the gaps is calculated as the following The gap area indicating the area of the gap Calculated as a gap area acquisition means for acquiring the gap area, and a chemical injection rate control means for controlling the chemical injection rate of the flocculant so that the acquired gap area becomes the target area. , and the machine learning model is a model that performs machine learning using semantic segmentation to determine whether each pixel of the input flocculated sludge image is in the region of the gaps or in the region other than the region of the gaps .

Advantages of the Invention

[0011] According to the present invention, it is possible to appropriately and earlier control the state of the flocs without diluting the concentration of the sludge or adding a new device.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0014] <1. Configuration of Sewage Sludge Treatment Equipment> First, with reference to FIG. 1, the configuration of the sewage sludge treatment equipment according to this embodiment will be described. FIG. 1 is a diagram showing an example of the configuration of the sewage sludge treatment equipment according to an embodiment of the present invention.

[0015] As shown in FIG. 1, the sewage sludge treatment equipment of this embodiment includes, for example, a coagulation mixing tank 1, a thickener 2, a dehydrator 3, a camera 10, a PC (Personal Computer) 20, and a PLC (Programmable Logic Controller).

[0016] (1) Coagulation Mixing Tank 1 The coagulation mixing tank 1 is equipment for adding a coagulant B to sludge A such as sewage sludge like mixed raw sludge generated from a sewage treatment plant and supplied, and coagulating it. As shown in FIG. 1, sludge A is supplied to the coagulation mixing tank 1 from a high-speed mixer 1A. 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 sludge A. A stirring blade 1b is attached to a rotating shaft 1a along the central axis of the high-speed mixer 1A, and a motor 1c is provided at the upper part. In the high-speed mixer 1A, the rotating shaft 1a and the stirring blade 1b are rotated by the motor 1c, so that the sludge A and the coagulant B are stirred and mixed. The agglomeration mixing tank 1 is provided with a bottomed cylindrical agglomeration tank 1C having a central axis extending in the vertical direction, in which sludge A mixed with flocculant B is supplied and held from the bottom. In this agglomeration tank 1C, stirring blades 1e are attached to a rotating shaft 1d along the central axis of the agglomeration tank 1C, and the rotating shaft 1d and the stirring blades 1e are rotated by a motor 1f provided in the upper part of the agglomeration tank 1C, so that stirring means 1D for stirring and mixing sludge A and flocculant B is provided. The agglomerated sludge C containing flocs stirred and mixed with flocculant B by this stirring means 1D is withdrawn from the upper part of the agglomeration tank 1C and supplied to the thickener 2.

[0017] (2) Thickener 2 The thickener 2 is a facility for thickening the agglomerated sludge C in which the solid content has been agglomerated to a certain extent by the agglomeration mixing tank 1. The thickener 2 in the present embodiment is a vertical filtration thickener, and is provided with a bottomed cylindrical thickening tank 2A having a central axis extending in the vertical direction, similar to the agglomeration tank 1C, in which the agglomerated sludge C supplied from the agglomeration mixing tank 1 is held. The agglomerated sludge C is supplied into the thickening tank 2A from the upper part of the thickening tank 2A. However, the body of this thickening tank 2A is a thickening filtration screen 2a formed by a wedge wire, punching metal, etc., and the outer periphery of this thickening filtration screen 2a is a jacket-shaped filtrate chamber 2b.

[0018] Further, in this thickening tank 2A, a screw 2d is attached to a rotating shaft 2c along the central axis of the thickening tank 2A, and conveying means 2B for conveying the agglomerated sludge C is provided by rotating the rotating shaft 2c and the screw 2d by a motor 2e provided in the upper part of the thickening tank 2A. The agglomerated sludge C supplied from the upper part of the thickening tank 2A is conveyed downward by this conveying means 2B, while moisture is separated and thickened by the thickening filtration screen 2a, and is withdrawn from the bottom of the thickening tank 2A and supplied to the thickened sludge supply path 4 as thickened sludge D.

[0019] Note that the bottoms of this thickening tank 2A and the above-mentioned agglomeration tank 1C are formed in a frustum shape that tapers downward. Further, the moisture separated from the agglomerated sludge C by the thickening filtration screen 2a is accommodated in the filtrate chamber 2b and treated as return water E.

[0020] Furthermore, in the present embodiment, concentrated warm water F in the range of a temperature of 50°C or higher and lower than 100°C, preferably in the range of 60°C or higher and 90°C or lower, is supplied to the concentrator 2 by the pump 2C and mixed with the flocculated sludge C supplied from the flocculation mixing tank 1. The concentrator 2 may be supplied with the concentrated warm water F by, for example, concentrated warm water supply means (not shown), or the drainage J discharged from the drain pipe 3H of the dehydrator 3 may be supplied as the concentrated warm water F.

[0021] Here, the rotating shaft 2c of the conveying means 2B of the concentrator 2 is in the shape of a hollow cylinder, and a large number (a plurality) of through holes are formed in the cylindrical wall portion of the rotating shaft 2c. Then, the concentrated warm 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 and mixed with the flocculated sludge C supplied and held in the concentration tank 2A from the flocculation mixing tank 1. Thereby, in the present embodiment, in this concentrator 2, the flocculated sludge C is heated, the protein is heat-denatured, the water that has been retained is separated, and is discharged as the return water E together with the concentrated warm water F, and the concentrated sludge D is concentrated to a predetermined concentration.

[0022] A pump 4A for sending the concentrated sludge D to the dehydrator 3 is provided in the concentrated sludge supply path 4 to which the concentrated sludge D concentrated in this way is supplied, and a high-speed mixer 4B is provided between the pump 4A and the dehydrator 3. An aggregating agent G such as an inorganic aggregating agent such as ferric polysulfate (PFS) or a polymer aggregating agent is supplied to the high-speed mixer 4B by the pump 4C and added to and mixed with the concentrated sludge D.

[0023] (3) Dehydrator 3 The dehydrator 3 is a facility for dehydrating the concentrated sludge D that has been concentrated by the concentrator 2 and to which the flocculant G has been added and mixed. In the dehydrator 3, a filter screen 3B for filtering the concentrated sludge D is disposed within the casing 3A. Of the plurality of spaces within the casing 3A separated by this filter screen 3B, the concentrated sludge D is supplied to the first space 3A1. The dehydrator 3 in the present embodiment is a vertical screw press, and moreover, it includes an inner filter screen 3a as the second filter screen 3B that is disposed within the casing 3A in a cylindrical or conical shape centered on an axis extending in the vertical direction and coaxial with the casing 3A. Further, the dehydrator 3 includes an outer filter screen 3b that is disposed within the casing 3A at an interval outside the inner filter screen 3a in a cylindrical or conical shape coaxial with the inner filter screen 3a. Further, the dehydrator 3 includes a ribbon screw 3d that is spirally twisted around the above axis and is accommodated between the inner filter screen 3a and the outer filter screen 3b, and is relatively rotated around the above axis with respect to the inner filter screen 3a and the outer filter screen 3b by a motor 3c.

[0024] And the space between these inner filter screen 3a and outer filter screen 3b is the above first space 3A1 and the concentrated sludge D is supplied, and the space inside the inner filter screen 3a and the space within the casing 3A outside the outer filter screen 3b are the second space 3A2. To this second space 3A2, dehydration warm water H having a temperature in the range of 50°C or more and less than 100°C, desirably in the range of 60°C or more and 90°C or less, is supplied by a pump 3P from dehydration warm water supply means (not shown). Incidentally, these inner filter screen 3a and outer filter screen 3b are also formed by wedge wire, punching metal, or the like.

[0025] 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 through a supply pipe 3f connected to an annular plate-shaped 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 conveyed upward by the relative rotation of the ribbon screw 3d while water is separated by the inner filtration screen 3a and the outer filtration screen 3b.

[0026] Also, an annular plate-shaped substrate 3C is disposed at the upper part inside the casing 3A, and the outer filtration screen 3b is attached and fixed to the inner peripheral part of this substrate 3C. Further, a lid 3D is disposed at the upper opening of the casing 3A above this substrate 3C. The inner filtration screen 3a is attached and fixed to this lid 3D, and the motor 3c is disposed on this lid 3D and rotates the ribbon screw 3d through a cylindrical screw support that covers the upper part of the inner filtration screen 3a. In this embodiment, the inner filtration screen 3a and the outer filtration screen 3b are fixed to the casing in this way, and the ribbon screw 3d is rotated by the motor 3c. Conversely, the ribbon screw 3d may be fixed and the inner filtration screen 3a and the outer filtration screen 3b may be rotated, or the ribbon screw 3d and the inner filtration screen 3a and the outer filtration screen 3b may be rotated in opposite directions to each other.

[0027] Furthermore, the upper space inside the casing 3A between these substrate 3C and the lid 3D is a discharge chamber 3E, and the annular upper opening of the first space 3A1 in this discharge chamber 3E is a discharge port 3F. A pressing ring 3G having a frustum-shaped outer peripheral surface centered on the above axis that slopes upward as it goes toward the outer peripheral side is disposed at this discharge port 3F. The dewatered sludge I dehydrated from the concentrated sludge D with water separated while being conveyed upward by the ribbon screw 3d in the first space 3A1 flows out into the discharge chamber 3E while being pressed by the pressing ring 3G at the discharge port 3F and is discharged.

[0028] Also, in this embodiment, the dewatered warm water H is supplied from the bottom of the casing 3A into the second space 3A2 within the casing 3A. The dewatered warm water H thus supplied into the second space 3A2 heats the concentrated sludge D within the first space 3A1. As a result, the water that had been retained due to the heat denaturation of the protein in the concentrated sludge D separates out. It is filtered by the inner filtration screen 3a and the outer filtration screen 3b and is discharged as drainage J from the drain pipe 3H that rises from the second space 3A2, together with the dewatered warm water H that has been cooled by heating the concentrated sludge D.

[0029] (4) Camera 10 The camera 10 acquires an image (still image or moving image) of the flocculated sludge C containing the flocs in which the sludge A has been flocculated by the flocculant B in the flocculation tank 1C. The camera 10 is communicably connected to the PC 20 and transmits the image of the flocculated sludge C taken (hereinafter also referred to as the "flocculated sludge image") to the PC 20. The position where the camera 10 is provided may be any position as long as it can image the flocculated sludge C. For example, as shown in FIG. 1, the camera 10 is provided above the flocculation tank 1C so as to be able to image the inside of the flocculation tank 1C. Note that the position where the camera 10 is provided is not limited to above the flocculation tank 1C. Also, the camera 10 may be provided inside the flocculation tank 1C or outside the flocculation tank 1C as long as it can image the inside of the flocculation tank 1C. Further, the camera 10 may image the flocculated sludge C with the timing of shooting being when the stirring blade 1e of the stirring means 1D provided in the flocculation tank 1C is at a fixed-point position. In this case, for example, by shooting immediately after the stirring blade 1e of the stirring means 1D provided in the flocculation tank 1C passes through the shooting position of the camera 10, it becomes easier to shoot an image in a state where the flocs are stationary or the movement of the flocs is slow.

[0030] (5) PC 20 The PC 20 is a device that controls the state of the flocs in the flocculated sludge C formed in the flocculation mixing tank 1 and is an example of a floc state control device. The floc state control device may be, for example, a server device. PC20 receives the flocculated sludge image captured by camera 10 from camera 10. The PC20 according to this embodiment determines and controls the state of the flocs based on the flocculated sludge image received from camera 10 as an example. PC20 is communicably connected to PLC30. PC20 transmits a control signal for controlling the state of the flocs to PLC30. The PC20 according to this embodiment transmits, as an example, a signal for controlling the rotation speed of pump 1B or a signal for controlling the rotation speed of motor 1c of high-speed mixer 1A to PLC30. By controlling the rotation speed of pump 1B, the amount of flocculant B supplied from pump 1B to high-speed mixer 1A can be controlled. Thereby, the dosing rate of flocculant B added to sludge A can be controlled. By controlling the rotation speed of motor 1c of high-speed mixer 1A, the rotation of the rotating shaft 1a and stirring blades 1b of high-speed mixer 1A can be controlled. Thereby, the mixing condition of sludge A and flocculant B in high-speed mixer 1A can be controlled.

[0031] As another embodiment, PC20 may transmit a signal for controlling the rotation speed of motor 1f of stirring means 1D to PLC30. By controlling the rotation speed of motor 1f of stirring means 1D, the rotation of the rotating shaft 1d and stirring blades 1e of stirring means 1D can be controlled. Thereby, the mixing condition of sludge A and flocculant B in stirring means 1D can be controlled.

[0032] (6)PLC30 PLC30 is a device that controls the operation of the controlled object. PLC30 controls the operation of the controlled object based on the control signal received from PC20. The control signal includes, for example, a control value indicating the control amount of each controlled object. The controlled object is, for example, pump 1B and motor 1c of high-speed mixer 1A. When the controlled object is pump 1B, PLC30 controls the rotation speed of pump 1B based on the control signal received from PC20. Also, when the controlled object is motor 1c of high-speed mixer 1A, PLC30 controls the rotation speed of motor 1c of high-speed mixer 1A based on the control signal received from PC20.

[0033] <Functional Configuration of the 2.PC> As described above, with reference to FIG. 1, the configuration of the sludge treatment facility has been described. Subsequently, with reference to FIGS. 2 to 7, the functional configuration of the PC20 will be described. FIG. 2 is a diagram showing an example of the functional configuration of the PC according to an embodiment of the present invention. As shown in FIG. 2, the PC20 includes an input unit 210, a communication unit 220, a storage unit 230, an output unit 240, and a control unit 250.

[0034] (1) Input Unit 210 The input unit 210 has a function of receiving input from the user. The input unit 210 is realized by an input device such as a keyboard, a mouse, a touch panel, etc. The input device may be a device that the PC20 is pre-equipped with as hardware, or a device externally connected to the PC20.

[0035] (2) Communication Unit 220 The communication unit 220 has a function of transmitting and receiving various information. For example, the communication unit 220 receives the aggregated sludge image from the camera 10. Also, the communication unit 220 transmits a control signal to the PLC30.

[0036] (3) Storage Unit 230 The storage unit 230 has a function of storing various information. The storage unit 230 is composed of a storage medium, for example, an HDD (Hard Disk Drive), a NAS (Network Attached Storage), an SSD (Solid State Drive), a flash memory, an EEPROM (Electrically Erasable Programmable Read Only Memory), a RAM (Random Access read / write Memory), a ROM (Read Only Memory), or any combination of these storage media.

[0037] (4) Output Unit 240 The output unit 240 has a function of outputting various types of information. The output unit 240 is realized, for example, by a display device such as a display. The display device may be a device that the PC 20 is pre-equipped with as hardware, or a device externally connected to the PC 20.

[0038] (5) Control unit 250 The control unit 250 has a function of controlling the overall operation of the PC 20. The control unit 250 is realized, for example, by causing the CPU (Central Processing Unit) that the PC 20 is equipped with as hardware to execute a program. As shown in FIG. 2, the control unit 250 includes a flocculated sludge image acquisition unit 251, an image selection unit 252, a region determination unit 253, an interstice area acquisition unit 254, a chemical injection rate control unit 255, and a rotation speed control unit 256.

[0039] (5-1) Flocculated sludge image acquisition unit 251 The flocculated sludge image acquisition unit 251 has a function of acquiring a flocculated sludge image. For example, the flocculated sludge image acquisition unit 251 acquires the flocculated sludge image captured by the camera 10 and transmitted to the PC 20 and received by the communication unit 220 of the PC 20.

[0040] Here, with reference to FIGS. 3 to 5, the relationship between the state of the flocs and the area of the interstices formed between the flocs will be described. FIGS. 3 to 5 are diagrams showing an example of a flocculated sludge image.

[0041] FIG. 3 shows a flocculated sludge image 40 in which the average value of the area of each interstice is 150. The interstice formed in the flocculated sludge shown in the flocculated sludge image 40 is, for example, the interstice 41. FIG. 4 shows a flocculated sludge image 50 in which the average value of the area of each interstice is 600. The interstice formed in the flocculated sludge shown in the flocculated sludge image 50 is, for example, the interstice 51. FIG. 5 shows a flocculated sludge image 60 in which the average value of the area of each interstice is 1000. The interstice formed in the flocculated sludge shown in the flocculated sludge image 60 is, for example, the interstice 61.

[0042] When comparing the flocculated sludge images 40, 50, and 60 respectively, it can be seen that when the injection amount of the flocculant is increased, the average value of the area of each gap increases, and when the injection amount of the flocculant is decreased, the average value of the area of each gap decreases. From this, it can be determined whether the state of the flocs is good or bad based on the area of the gaps (hereinafter also referred to as "gap area") rather than the area of the flocs. When the flocs overlap with other flocs, the area of the flocs cannot be accurately calculated. Using the inaccurate area of the flocs, the state of the flocs cannot be accurately grasped either. On the other hand, since the gap area is not affected by the influence of floc overlap, etc., the area of each gap can be calculated accurately one by one. Therefore, by using the gap area instead of the area of the flocs, the state of the flocs can be grasped and controlled with higher accuracy.

[0043] (5-2) Image selection unit 252 The image selection unit 252 has a function of selecting an image suitable for controlling the state of the flocs from the flocculated sludge images acquired by the flocculated sludge image acquisition unit 251. For example, the image selection unit 252 performs image processing for detecting the velocity vector of the flocs using optical flow (OF) on the flocculated sludge image acquired by the flocculated sludge image acquisition unit 251. Then, the image selection unit 252 selects the flocculated sludge image according to the detection result of the velocity vector of the flocs by the optical flow.

[0044] Specifically, the image selection unit 252 uses optical flow to detect the velocity vector of the flock (i.e., the movement of the flock) from the flocculated sludge images (a plurality of still images or moving images) in the flocculation mixing tank 1 acquired by the flocculated sludge image acquisition unit 251, and acquires the flocculated sludge image when the vector value of the detected velocity vector of the flock is less than a predetermined threshold. The vector value is, for example, the total value of the x - component or y - component of the plurality of detected velocity vectors. Alternatively, it may be the magnitude (absolute value) of the velocity vector, and may be not only the total value of the x - component or y - component of the velocity vector, but also the average value. The predetermined threshold is preferably, for example, a value that can determine that the flock is stationary in the flocculation mixing tank 1, or a value that can determine that the movement of the flock is slow.

[0045] With such a configuration, the image selection unit 252 can select and acquire the flocculated sludge image when the flock is stationary or the flocculated sludge image when the movement of the flock is slow. That is, the image selection unit 252 can exclude the flocculated sludge image in which the sludge is fluid and not clear due to the influence of stirring in the flocculation mixing tank 1. Thereby, when controlling the state of the flock, the PC 20 can use the flocculated sludge image in which the flock is clearer, so that the accuracy of controlling the state of the flock can be improved compared with the case of using the flocculated sludge image in which the flock is not clear.

[0046] (5 - 3) Region determination unit 253 The region determination unit 253 has a function of determining the gap region and the region other than the gap region in the flocculated sludge image acquired by the image selection unit 252. For example, the region determination unit 253 uses a machine learning model for determining the gap region and the region other than the gap region in the flocculated sludge image to determine the gap region and the region other than the gap region in the flocculated sludge image acquired by the image selection unit 252.

[0047] The machine learning model used by the region determination unit 253 is, for example, a model obtained by performing machine learning using semantic segmentation (SS) to determine whether each pixel of the input flocculated sludge image is in the gap region or outside the gap region. For example, the model uses, as teacher data, an image in which a person has previously painted the "gap region" and "outside the gap region" in different colors. The model learns a neural network model that can classify the "gap region" and "outside the gap region" from the original image in the same way as the teacher data by using a machine learning method, and automatically extracts and creates feature amounts for classification.

[0048] The region determination unit 253 inputs the flocculated sludge image acquired by the image selection unit 252 to a learned model obtained by performing machine learning using semantic segmentation. The learned model outputs a result of classifying each pixel of the input flocculated sludge image into either the "gap region" or the "outside the gap region". The region determination unit 253 acquires the result output by the learned model as the determination result.

[0049] Note that the region determination unit 253 may classify each pixel of the flocculated sludge image into either the "gap region" or the "outside the gap region" by binarizing the flocculated sludge image without using the above-described learned model.

[0050] (5-4) Gap area acquisition unit 254 The gap area acquisition unit 254 has a function of acquiring a gap area indicating the area of the gap generated between a plurality of flocs based on the flocculated sludge image. For example, the gap area acquisition unit 254 calculates, as the gap area, the area of the region determined to be the gap region in the flocculated sludge image based on the determination result acquired by the region determination unit 253. At this time, the gap area acquisition unit 254 calculates the total area of the gap regions or the average area of the gap regions as the gap area. Note that when a plurality of gaps are continuous, the gap area acquisition unit 254 calculates the gap area by treating the plurality of gaps as one gap.

[0051] The gap area acquisition unit 254 may calculate the total area or the average area of the gap region, excluding at least one area in descending order of area or at least one area in ascending order of area, among the areas of the gap regions. When a plurality of gaps are continuous, the gap area acquisition unit 254 ranks the plurality of gaps as one gap and then performs ranking in order of area size. Then, the gap area acquisition unit 254 excludes the upper-ranked (larger area) and lower-ranked (smaller area) of the ranked gap areas and calculates the total area or the average area of the gap region. Thereby, the gap area acquisition unit 254 can reduce the determination error caused by noise (such as dust or bubbles in the sludge) or fluctuations (such as the influence of agitation) when imaging the flocculated sludge.

[0052] (5-5) Chemical injection rate control unit 255 The chemical injection rate control unit 255 has a function of controlling the chemical injection rate of the flocculant. For example, the chemical injection rate control unit 255 controls the chemical injection rate of the flocculant so that the gap area acquired by the gap area acquisition unit 254 becomes the target area. For example, the chemical injection rate control unit 255 determines the rotation speed of the pump 1B to bring the gap area closer to the target area from the relationship between the chemical injection rate of the flocculant and the gap area. 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.

[0053] Here, with reference to FIG. 6, the relationship between the chemical injection rate of the flocculant and the gap area will be described. FIG. 6 is a diagram showing an example of the relationship between the chemical injection rate of the flocculant and the gap area according to an embodiment of the present invention. The horizontal axis of the graph shown in FIG. 6 indicates the chemical injection rate (%) of the flocculant, and the vertical axis indicates the gap area. From the graph shown in FIG. 6, it can be seen that the gap area increases as the chemical injection rate increases. However, when the chemical injection rate of the flocculant increases to a certain extent, it can be seen that the gap area decreases when the chemical injection rate of the flocculant further increases. This is presumably because the flocs are dispersed due to over-injection and the floc diameter becomes smaller.

[0054] The chemical injection rate control unit 255 controls the chemical injection rate of the flocculant so that the gap area acquired by the gap area acquisition unit 254 becomes the target area, based on the relationship between the chemical injection rate of the flocculant and the gap area as shown in FIG. 6. For example, as shown in FIG. 6, assume that the target area is set to 1300. When the gap area acquired by the gap area acquisition unit 254 is smaller than 1300, the chemical injection rate control unit 255 can bring the gap area closer to the target area by increasing the chemical injection rate of the flocculant. On the other hand, when the gap area acquired by the gap area acquisition unit 254 is larger than 1300, the chemical injection rate control unit 255 may bring the gap area closer to the target area by increasing the chemical injection rate of the flocculant, or may bring the gap area closer to the target area by decreasing the chemical injection rate of the flocculant.

[0055] Here, the setting of the target area will be described. For example, the target area is set in consideration of the operation efficiency of the equipment downstream of the agglomeration mixing tank 1. As an example, the target area is set so that the operation efficiency is maximized. The equipment downstream of the agglomeration mixing tank 1 is, for example, the thickener 2 shown in FIG. 1. When the thickener 2 is a general thickener, the operation efficiency is the thickening efficiency in the thickener 2. When the thickener 2 is a heated thickener, the operation efficiency is the heating efficiency in the thickener 2. The heating efficiency is calculated, for example, by the following formula (1). Heating efficiency (%) = ΔTact / ΔTide × 100 …(1) In the above formula (1), ΔTact = concentrated sludge temperature - raw sludge temperature …(2) ΔTide = (T1 × Q1 + T2 × Q2) / (Q1 + Q2) …(3) where, in the above formula (3), T1 is the raw sludge temperature (agglomerated sludge temperature), T2 is the warm water temperature, Q1 is the concentrated sludge flow rate, and Q2 is the warm water flow rate.

[0056] Here, with reference to FIG. 7, the relationship between the gap area and the heating efficiency will be described. FIG. 7 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. The horizontal axis of the graph shown in FIG. 7 indicates the gap area, and the vertical axis indicates the heating efficiency (%). From the trends of the graphs shown in Fig. 7, it can be seen that as the gap area increases, the heating efficiency tends to increase. However, when the gap area reaches a certain size, it can be seen that if the gap area increases further, the heating efficiency tends to decrease. That is to say, it can be said that if the floc is too large, the heating efficiency may decrease.

[0057] Based on the relationship between the gap area and the heating efficiency as shown in Fig. 7, the chemical injection rate control unit 255 controls the chemical injection rate of the flocculant so that the gap area acquired by the gap area acquisition unit 254 becomes the area where the heating efficiency is maximized. For example, in the example of the graph shown in Fig. 7, the heating efficiency is maximized when the gap area is around 1250. That is, the target area is set to be around 1250. Then, the chemical injection rate control unit 255 controls the chemical injection rate of the flocculant in the same manner as in the example of Fig. 6 so that the gap area acquired by the gap area acquisition unit 254 approaches the target area of 1250.

[0058] Also, the target area may be set according to the concentration of the sludge. For example, the chemical injection rate control unit 255 sets a target area according to the concentration of the sludge, and controls the chemical injection rate of the flocculant so that the gap area acquired by the gap area acquisition unit 254 approaches the target area. Thereby, in order to control the state of the floc, it is not necessary to adjust the concentration of the sludge. That is, the state of the floc can be controlled without diluting the sludge or adding a new device to adjust the concentration of the sludge.

[0059] (5-6) Rotation speed control unit 256 The rotation speed control unit 256 controls the rotation speed of the motor 1c of the high-speed mixer 1A that stirs the sludge sent to the agglomeration mixing tank 1 so that the gap area acquired by the gap area acquisition unit 254 becomes the target area. For example, the rotation speed control unit 256 determines the rotation speed of the motor 1c for approaching the gap area to the target area from the relationship between the rotation speed of the motor 1c and the gap area. Then, the rotation speed control unit 256 transmits a control signal indicating the determined rotation speed of the motor 1c from the communication unit 220 to the PLC 30.

[0060] Incidentally, as another embodiment, the rotation speed control unit 256 may control the rotation speed of the motor 1f of the stirring means 1D that stirs the sludge in the agglomeration mixing tank so that the gap area acquired by the gap area acquisition unit 254 becomes the target area. In this case, for example, the rotation speed control unit 256 determines the rotation speed of the motor 1f for bringing the gap area closer to the target area from the relationship between the rotation speed of the motor 1f and the gap area. Then, the rotation speed control unit 256 transmits a control signal indicating the determined rotation speed of the motor 1f from the communication unit 220 to the PLC 30.

[0061] Incidentally, in the present embodiment, in order to bring the gap area closer to the target area, the control by the chemical injection rate control unit 255 is preferentially performed over the control by the rotation speed control unit 256. This is because it is more time-efficient to control the chemical injection rate. If the gap area can be brought closer to the target area only by the control by the chemical injection rate control unit 255, the rotation speed control unit 256 may not perform the control. On the other hand, if the gap area cannot be brought closer to the target area only by the control by the chemical injection rate control unit 255, the rotation speed control unit 256 performs the control.

[0062] <3. Flow of processing> As described above, the functional configuration of the PC 20 has been described with reference to FIGS. 2 to 7. Subsequently, with reference to FIG. 8, the flow of processing in the PC 20 will be described. FIG. 8 is a flowchart showing an example of the flow of processing in the PC 20 according to the embodiment of the present invention. Incidentally, in FIG. 8, as an example, an example in which the rotation speed control unit 256 controls the rotation speed of the motor 1c of the high-speed mixer 1A is shown.

[0063] As shown in FIG. 8, first, the flocculated sludge image acquisition unit 251 of the PC 20 acquires the flocculated sludge image that the camera 10 has captured and transmitted to the PC 20 and that the communication unit 220 of the PC 20 has received (step S101).

[0064] Next, the image selection unit 252 of the PC 20 performs image processing for detecting the velocity vector of the flock using optical flow on the flocculated sludge image acquired by the flocculated sludge image acquisition unit 251 (step S102). After detecting the velocity vector of the flock, the image selection unit 252 selects a flocculated sludge image according to the detection result of the velocity vector of the flock (step S103).

[0065] Next, the region determination unit 253 of the PC 20 determines, using a machine learning model, the region of the gap and the region other than the region of the gap in the flocculated sludge image acquired by the image selection unit 252 (step S104).

[0066] Next, the gap area acquisition unit 254 of the PC 20 calculates, based on the determination result acquired by the region determination unit 253, the area of the region determined as the region of the gap in the flocculated sludge image as the gap area (step S105).

[0067] Next, the chemical injection rate control unit 255 of the PC 20 controls the chemical injection rate of the flocculant so that the gap area acquired by the gap area acquisition unit 254 becomes the target area (step S106). After controlling the chemical injection rate, when the gap area approaches the target area and becomes an appropriate value (step S107 / YES), the process ends. On the other hand, when the gap area after controlling the chemical injection rate is not an appropriate value (step S107 / NO), the process proceeds to step S108.

[0068] When the process proceeds to step S108, the rotation speed control unit 256 controls, for example, the rotation speed of the motor 1c of the high-speed mixer 1A that stirs the sludge sent to the flocculation mixing tank 1 so that the gap area acquired by the gap area acquisition unit 254 becomes the target area (step S108), and the process ends.

[0069] <4. Specific Example> As described above, with reference to FIG. 8, the processing flow in the PC 20 has been described. Subsequently, with reference to FIG. 9, a specific example will be described. FIG. 9 is a diagram showing a specific example according to an embodiment of the present invention.

[0070] FIG. 9 shows the time-series changes of the gap area and the chemical injection rate when the chemical injection rate is controlled so that the gap area becomes the target area, and the measured values of the time-series changes of the heating efficiency corresponding to the time-series changes. The target area is set to 1250 ± 100. As shown in Fig. 9, as a result of controlling the chemical injection rate so that the gap area becomes 1250 ± 100, as shown by the results from 14:50 to 15:50, the chemical injection rate was in the range of 0.40% to 0.41%, and the heating efficiency maintained a high level of 113% on average. In addition, as a result of conducting an experiment assuming that the chemical injection rate decreased to 0.37% due to concentration fluctuations without controlling the chemical injection rate, as shown by the results from 15:55 to 16:20, the gap area dropped to about 800, and the heating efficiency fell below 100%. From the above, it can be said that by properly maintaining the gap area by controlling the chemical injection rate, the heating efficiency can be kept high. Also, by properly maintaining the gap area, it becomes possible to optimize the chemical injection amount, safely operate the concentrator 2, and also reduce the chemical injection amount (cost reduction).

[0071] As described above, the PC20 (floc state control device) according to this embodiment includes a flocculated sludge image acquisition unit 251, a gap area acquisition unit 254, and a chemical injection rate control unit 255. The flocculated sludge image acquisition unit 251 acquires a flocculated sludge image obtained by imaging flocculated sludge containing flocs in which a flocculant and sludge are mixed in the flocculation mixing tank 1. The gap area acquisition unit 254 acquires a gap area indicating the area of the gaps generated between a plurality of flocs based on the acquired flocculated sludge image. The chemical injection rate control unit 255 controls the chemical injection rate of the flocculant so that the acquired gap area becomes the target area.

[0072] With such a configuration, the PC20 according to this embodiment can control the state of the flocs with higher accuracy using the gap area that is not affected by factors such as the overlap of the flocs. Since it is not affected by factors such as the overlap of the flocs, the state of the flocs can be controlled without diluting the sludge or adding a new device to adjust the concentration of the sludge.

[0073] Therefore, the PC20 according to this embodiment can appropriately control the state of the flock at a location where it is easier to take a picture from the subsequent piping and it is possible to adjust the flocculant earlier, without diluting the sludge concentration or adding a new device to reduce the overlap of the flock.

[0074] As described above, the embodiments of the present invention have been explained. Note that part or all of the PC20 in the above-described embodiments may be realized by a computer. In that case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to realize it. Here, the "computer system" shall include hardware such as an OS and peripheral devices. Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, etc., and a storage device such as a hard disk built in a computer system. Furthermore, the "computer-readable recording medium" also includes those that dynamically hold a program for a short time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, and those that hold a program for a certain time, such as volatile memory inside a computer system that becomes a server or a client in that case. Also, the above program may be for realizing a part of the above-described functions, and may further be realized in combination with a program already recorded in a computer system for realizing the above-described functions, or may be realized using a programmable logic device such as an FPGA (Field Programmable Gate Array).

[0075] As described above, the embodiments of this invention have been explained in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the gist of this invention.

Explanation of Reference Numerals

[0076] 1…Coagulation mixing tank, 1a…Rotating shaft, 1A…High-speed mixer, 1b…Agitating blade, 1B…Pump, 1c…Motor, 1C…Coagulation tank, 1d…Rotating shaft, 1D…Agitating means, 1e…Agitating blade, 1f…Motor, 2…Thickener, 2a…Concentrating and filtering screen, 2A…Concentrating 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…Cover, 3e…Connecting plate, 3E…Discharge chamber, 3f…Supply pipe, 3F…Outlet, 3G…Squeezing 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 section, 220…Communication section, 230…Memory section, 240…Output section, 250…Control section, 251…Coagulated sludge image acquisition section, 252…Image selection section, 253…Region determination section, 254…Gap area acquisition section, 255…Chemical injection rate control section, 256…Rotation speed control section

Claims

1. A flocculated sludge image acquisition unit that acquires a flocculated sludge image obtained by imaging flocculated sludge containing flocs flocculated by a flocculant in a flocculation mixing tank; An area determination unit that determines, using a machine learning model that determines an area of a gap generated between a plurality of the flocs in the flocculated sludge image and an area other than the area of the gap, an area of the gap and an area other than the area of the gap in the acquired flocculated sludge image; A gap area acquisition unit that calculates an area of an area determined to be the area of the gap as a gap area indicating the area of the gap; A chemical injection rate control unit that controls a chemical injection rate of the flocculant so that the acquired gap area becomes a target area; Comprising; The machine learning model is a floc state control device that performs machine learning to determine whether each pixel of an input flocculated sludge image is in an area of a gap or an area other than the area of the gap using semantic segmentation.

2. An image selection unit that detects a velocity vector of the flocs using optical flow based on the flocculated sludge image and acquires a flocculated sludge image when a vector value of the detected velocity vector is less than a predetermined threshold; The floc state control device according to claim 1, further comprising.

3. The gap area acquisition unit calculates the total area of the area of the gap or the average area of the area of the gap as the gap area. The floc state control device according to any one of claims 1 to 2.

4. The gap area acquisition unit calculates the total area of the area of the gap or the average area of the area of the gap by excluding at least one area in descending order of area or at least one area in ascending order of area from the areas of the area of the gap. The floc state control device according to claim 3.

5. The target area is set so that the operating efficiency in equipment located downstream of the flocculation mixing tank is maximized. The floc state control device according to any one of claims 1 to 4.

6. The target area is set according to the concentration of the sludge. The floc state control device according to any one of claims 1 to 5.

7. A rotation speed control unit that controls at least one of the rotation speed of a mixer that stirs the sludge to be sent to the flocculation mixing tank and the rotation speed of a stirrer that stirs the flocculated sludge in the flocculation mixing tank so that the acquired gap area becomes the target area. The floc state control device according to any one of claims 1 to 6, further comprising

8. A sludge treatment facility comprising the floc state control device according to any one of claims 1 to 7.

9. An aggregated sludge image acquisition process in which an aggregated sludge image acquisition unit acquires an aggregated sludge image obtained by imaging aggregated sludge containing flocs in which sludge is aggregated by a flocculant in an aggregation mixing tank, An area determination process in which an area determination unit determines, using a machine learning model that determines an area of a gap generated between a plurality of the flocs in the aggregated sludge image and an area other than the area of the gap, the area of the gap and the area other than the area of the gap in the acquired aggregated sludge image, A gap area acquisition process in which a gap area acquisition unit calculates the area of the region determined to be the region of the gap as a gap area indicating the area of the gap, A chemical injection rate control process in which a chemical injection rate control unit controls the chemical injection rate of the flocculant so that the acquired gap area becomes a target area, including The machine learning model is a floc state control method that performs machine learning using semantic segmentation to determine whether each pixel of an input aggregated sludge image is in a gap region or outside the gap region.

10. A computer, An aggregated sludge image acquisition means for acquiring an aggregated sludge image obtained by imaging aggregated sludge containing flocs in which sludge is aggregated by a flocculant in an aggregation mixing tank, An area determination means for determining, using a machine learning model that determines an area of a gap generated between a plurality of the flocs in the aggregated sludge image and an area other than the area of the gap, the area of the gap and the area other than the area of the gap in the acquired aggregated sludge image, A gap area acquisition means for calculating the area of the region determined to be the region of the gap as a gap area indicating the area of the gap, A chemical injection rate control means for controlling the chemical injection rate of the flocculant so that the acquired gap area becomes a target area, functioning as The machine learning model is a program for a model that performs machine learning using semantic segmentation to determine whether each pixel of an input aggregated sludge image is in a gap region or outside the gap region.

Images