Flocculation floc monitoring and controlling system and sludge dewatering device

Abstract

To provide a monitoring control system for flocculated floc capable of accurately detecting and monitoring the state of flocculated floc and capable of determining a proper chemical liquid injection ratio.SOLUTION: The monitoring control system 1 for the flocculated floc monitors and controls the state of the flocculated floc when the flocculated floc is transferred to a solid-liquid separation means 100 from a flocculation mixing means 10 for forming the flocculated floc by adding a flocculant to sludge and stirring the sludge. The sludge treatment apparatus includes a sludge supply path (30) having a gutter structure that is bridged between a coagulating and mixing means (10) and a solid-liquid separation means (100) and is provided with an inclination descending from the coagulating and mixing means (10) toward the solid-liquid separation means (100) to allow sludge in which coagulated flocs are formed to flow, an imaging means (50) that captures an image of the sludge flowing through the sludge supply path (30) from above a water surface thereof to obtain image information of the coagulated flocs in the sludge, a determination means (70) that determines a formation state of the coagulated flocs based on the image information, and a flocculant addition amount control means (80) that controls an addition amount of a flocculant to the coagulating and mixing means (10) according to the determined formation state of the coagulated flocs.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a monitoring and control system for flocculation and a sludge dewatering device. [Background technology]

[0002] Conventionally, as a pretreatment for solid-liquid separation of sludge, sludge is coagulated using a polymer coagulant to form coagulated flocs. The polymer coagulant must be adjusted appropriately depending on the properties and concentration of the sludge, and for this adjustment, the state of the coagulated flocs must be monitored appropriately.

[0003] Patent Document 1 discloses a flocculation monitoring device that mixes a polymer flocculant into wastewater such as industrial wastewater or domestic wastewater in a flocculation tank (2) to grow flocs, samples a portion of the wastewater containing the flocs, and guides it to a sampling trough (10) connected to the flocculation tank (2), photographs the wastewater flowing in the sampling trough (10) with a camera (16), and recognizes the state of the flocs in the wastewater using the photographic data from the camera (16).

[0004] Patent Document 2 also discloses a method (apparatus) for injecting a flocculant, in which a flocculant is added to a raw liquid introduced into a flocculation mixing tank (5) to form flocs of suspended matter, and the state of flocculation of the flocs in the raw liquid is photographed by a television camera (15) through an observation window (14) provided in a raw liquid supply pipe (13) that transfers the raw liquid containing the flocs to a dehydrator (12), and the flocculant injection rate is adjusted based on the photographed image. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 04-148849 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-7338 Summary of the Invention [Problem to be solved by the invention]

[0006] In the above Patent Documents 1 and 2, the state of the flocs is monitored by taking images of them using a camera (16) or a television camera (15) in the sampling trough (10) or the raw liquid supply pipe (13). This makes it possible to obtain more stable and accurate image information of the flocs than when the flocs are directly observed in the flocculation tank (2) or the flocculation mixing tank (5) during high-speed stirring, and thus allows for accurate injection of the flocculant (chemical solution).

[0007] Currently, there is a demand for a method that can detect the state of flocs more stably and accurately than the above-mentioned conventional methods, and that can inject a flocculant (chemical solution) more accurately.

[0008] The present invention has been made in view of the above points, and an object of the present invention is to provide a monitoring and control system for flocculation that can more accurately detect and monitor the state of flocculation, and can determine a more appropriate chemical injection rate.

[0009] Another object of the present invention is to provide a sludge dewatering apparatus that can effectively dewater sludge by appropriately adding a flocculant and appropriately controlling the operation of a solid-liquid separator. [Means for solving the problem]

[0010] The present invention is a monitoring and control system for flocculated flocs that monitors and controls the state of the flocculated flocs when the sludge in which the flocculated flocs have been formed is transferred from a flocculating and mixing means that forms the flocculated flocs by adding a flocculant to sludge and stirring it, to a solid-liquid separation means that separates the sludge in which the flocculated flocs have been formed, and is characterized by comprising: a sludge supply path having a trough structure that is bridged between the flocculating and mixing means and the solid-liquid separation means, and that has at least a portion that slopes downward from the flocculating and mixing means toward the solid-liquid separation means, through which the sludge in which the flocculated flocs have been formed flows; and imaging means that takes an image of the sludge flowing in the sludge supply path from above the water surface, thereby obtaining image information of the flocculated flocs in the sludge. There are no particular restrictions on the sludge that can be separated into solids and liquids, and it can include sewage sludge (excess sludge, mixed raw sludge, digested sludge), human waste treatment sludge, septic tank sludge, sludge and slurry containing suspended solids such as organic waste, oil-containing wastewater, etc. This system is particularly suitable for use with highly concentrated sludge. It is suitable for sludge with a concentration of 500 mg / L or more. The solid-liquid separation means may be any means capable of separating solids and liquids, such as a screw press, a belt press, or a concentrator. The flocculant may be an inorganic flocculant or an organic flocculant. According to the present invention, the sludge on which flocs have formed is passed through a sludge supply path having a trough structure, so that even if the turbidity concentration is high like sludge, the formed flocs can be identified with high accuracy even from above the water surface. This improves the accuracy of identifying flocs in the image captured by the imaging means from above the water surface, and enables appropriate control of the amount of flocculant added to the flocculating and mixing means.

[0011] In addition to the above features, the present invention is characterized by further comprising a discrimination means for discriminating the formation state of the flocs based on the image information obtained by the imaging means, and a flocculant addition amount control means for controlling the amount of flocculant to be added to the flocculation mixing means in accordance with the formation state of the flocs discriminated by the discrimination means. It is preferable that a machine learning model be used as a discrimination means for discriminating the formation state of flocs based on captured image information. By performing image classification and segmentation using the captured images with the machine learning model, it is possible to constantly monitor the state of flocs with high accuracy. It is preferable that the amount of chemical injection (or chemical injection rate) is calculated based on the state discrimination results obtained using the implemented machine learning model, that is, control is performed to gradually adjust the chemical injection amount (or chemical injection rate) to the appropriate amount while repeatedly determining the state using the implemented machine learning model until the appropriate chemical injection amount (or chemical injection rate) is obtained.

[0012] In addition to the above features, the present invention is characterized in that the bottom surface of the inclined sludge supply channel is a horizontal flat surface in a direction perpendicular to the flow direction of the sludge flowing through the sludge supply channel. According to the present invention, the depth of the sludge flowing in the sludge supply path can be maintained uniform, the accuracy of identifying flocculated flocs using an image captured by an imaging means from above the water surface can be further improved, and the amount of flocculant added to the flocculation mixing means can be more appropriately controlled.

[0013] In addition to the above features, the present invention is characterized in that the width dimension of the sludge supply path is equal to or greater than a predetermined width dimension that prevents flocs from overlapping with each other in an image captured by the imaging means, at least when the flocs are in an appropriate state. The width of the sludge supply path in which the flocs do not overlap each other (including the case where there is little overlap) is preferably a predetermined value or more, specifically 5 cm or more. According to the present invention, the dimensions and quantity of each floc can be accurately determined, thereby improving the accuracy of identifying flocs and enabling more appropriate control of the amount of flocculant added to the flocculation mixing means.

[0014] In addition to the above features, the present invention is characterized in that the inclination angle of the sludge supply path is equal to or greater than an inclination angle at which coagulated flocs in the sludge flowing through the sludge supply path do not accumulate on the bottom surface. The gradient of the sludge supply path so that the flocs do not accumulate at the bottom is preferably a predetermined value or more, specifically 5% or more. At the same time, the gradient of the sludge supply path so that the flocs do not become too fast and are destroyed on the solid-liquid separation means side is preferably a predetermined value or less, specifically 50% or less, more preferably 35% or less. According to the present invention, the flocs in the sludge can be reliably flowed along with the sludge flow without being retained in the sludge supply path, thereby further improving the accuracy of identifying the flocs and enabling more appropriate control of the amount of flocculant added to the flocculation mixing means.

[0015] In addition to the above features, the present invention is characterized in that the depth of the sludge flowing through the sludge supply path is set to a predetermined depth or less at which flocs in the image do not overlap with each other, at least when the flocs are in an appropriate state, when the sludge flowing through the sludge supply path is imaged by the imaging means. The depth of the sludge flowing into the sludge supply path where the flocs do not overlap each other (including the case where there is little overlap) is preferably a predetermined value or less, specifically 5 cm or less. According to the present invention, the dimensions and quantity of each floc can be accurately determined, thereby improving the accuracy of identifying flocs and enabling more appropriate control of the amount of flocculant added to the flocculation mixing means.

[0016] In addition to the above features, the present invention is characterized in that the flocculant addition amount control means determines a chemical injection rate X of the flocculant and a rate of change K by which to increase or decrease the chemical injection rate X, and if the discrimination means determines that the chemical injection rate X of the flocculant is appropriate based on the state of floc formation when the flocculant is operated at the chemical injection rate X, the chemical injection rate X of the flocculant is maintained. On the other hand, if the discrimination means determines that the chemical injection rate X of the flocculant is excessive based on the state of floc formation when the flocculant is operated at the chemical injection rate X of the flocculant, the chemical injection rate X is reduced from the chemical injection rate X by the rate of change K to set a new chemical injection rate X. On the other hand, if the discrimination means determines that the chemical injection rate X of the flocculant is too low, the chemical injection rate X is increased from the chemical injection rate X by the rate of change K to set a new chemical injection rate X, and when changing to the new chemical injection rate X, the rate of change K is halved to set a new rate of change K; this process is repeated until the chemical injection rate X of the flocculant is determined to be appropriate. According to the present invention, the number of times the chemical injection rate is changed is reduced, making it possible to reach an appropriate chemical injection rate in a shorter time than when the appropriate chemical injection rate is obtained by gradually increasing or decreasing the chemical injection rate. Furthermore, when an appropriate chemical injection rate is obtained by gradually increasing or decreasing the chemical injection rate, the amount of change in the chemical injection rate per change is small, and the change in the flocculated flocs per change is also small, making it difficult to determine whether the appropriate state has been reached. However, by using the present invention, the amount of change in the chemical injection rate per change can be made larger, and the change in the flocculated flocs per change is also larger, making it easier to determine whether the appropriate state has been reached.

[0017] In addition to the above features, the present invention is characterized in that the flocculant addition amount control means determines a chemical injection rate X of the flocculant, and when it is determined that the chemical injection rate X of the flocculant is appropriate from the state of flocculation formation determined by the discrimination means when the system is operated at the chemical injection rate X of the flocculant, the means maintains the chemical injection rate X of the flocculant, and when it is determined that the chemical injection rate X of the flocculant is excessive from the state of flocculation formation determined by the discrimination means when the system is operated at the chemical injection rate X of the flocculant, the means adjusts the chemical injection rate X based on the degree of flocculation formation determined by the discrimination means. The chemical injection rate X is increased by the change rate K, and the chemical injection rate X is reduced from the chemical injection rate X by the change rate K to set a new chemical injection rate X; on the other hand, if the chemical injection rate X of the flocculant is determined to be too low, the chemical injection rate X is increased from the chemical injection rate X by the change rate K to set a new chemical injection rate X; and this operation at the new chemical injection rate X is repeated until the chemical injection rate X of the flocculant is determined to be appropriate. Even with this configuration, an appropriate drug injection rate can be achieved in a short time. It is preferable that the rate of change K is determined to be a large value when the degree of excess or deficiency of the chemical injection rate X of the flocculant is large, and is determined to be a small value when the degree of excess or deficiency is small.

[0018] In addition to the above features, the present invention is characterized in that the flocculant addition amount control means predetermines a chemical injection rate X of the flocculant and a rate of change K by which to reduce the chemical injection rate X; and if the moving average of the output values ​​of the discrimination means of the floc formation state when operating at the chemical injection rate X of the flocculant continues for a certain period of time within a predetermined range A that is on the excessive side of the appropriate range, the means changes the chemical injection rate X to a new chemical injection rate X by reducing the chemical injection rate X by the rate of change K, repeating this process until the moving average is determined to be in a predetermined range B that is on the insufficient side of the predetermined range A within the appropriate range; on the other hand, if the result of this repetition determines that the chemical injection rate X of the flocculant is below the predetermined range B that is on the insufficient side, the means changes the chemical injection rate X to a new chemical injection rate X by increasing the chemical injection rate X by the rate of change K, repeating this process until it is determined to be in the predetermined range B that is on the insufficient side. This configuration effectively reduces the chemical injection rate, thereby reducing costs.

[0019] The present invention relates to a sludge dewatering apparatus having a flocculation and mixing means for adding a flocculant to sludge and stirring the sludge to flocculate the sludge to form flocs, and a solid-liquid separation means for performing solid-liquid separation of the sludge from which the flocs have formed, the apparatus also comprising: a monitoring and control system for the flocs; a second imaging means for obtaining image information of the sludge separated by the solid-liquid separation means or a third imaging means for obtaining image information of the state of the separated liquid separated by the solid-liquid separation means; and an operation control means for controlling the operation of the solid-liquid separation means using the image information of the sludge obtained by the second imaging means or the image information of the state of the separated liquid obtained by the third imaging means. The state of the separated liquid includes information on the state of the aggregated flocs remaining in the separated liquid, as well as the degree of turbidity and color of the separated liquid. According to the present invention, an image of sludge flowing through the sludge supply path is captured by an imaging means (first imaging means) to control the amount of flocculant added, thereby obtaining appropriate flocculated flocs. At the same time, the second or third imaging means can appropriately control the operation of the solid-liquid separation means, thereby achieving appropriate solid-liquid separation. Of course, the first imaging means may primarily control the amount of flocculant added, and the second or third imaging means may control the operation of the solid-liquid separation means while also controlling the amount of flocculant added secondary to the first imaging means. In other words, since the amount of flocculant added is appropriately controlled primarily by the first imaging means, the information obtained by the second or third imaging means does not need to be used to adjust the amount of flocculant added, and can be used primarily to control the operation of the solid-liquid separation means, thereby enabling more appropriate solid-liquid separation in the sludge dewatering apparatus. [Effects of the Invention]

[0020] According to the present invention, the quality of the state of the flocs can be detected and monitored more accurately, and a more appropriate chemical injection rate can be determined. Furthermore, according to the present invention, the dewatering of sludge in the sludge dewatering apparatus can be effectively carried out by appropriately adding a flocculant and appropriately controlling the operation of the solid-liquid separation means. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic diagram showing an example of a monitoring and control system 1 (solid-liquid separation device 1A) for flocs. [Figure 2] 2 is a schematic cross-sectional view of a main part of a sludge supply channel 30 (a schematic cross-sectional view taken along the line AA in FIG. 1). [Figure 3] FIG. 2 is a diagram showing an example of an operation flow of a solid-liquid separator 1A equipped with a monitoring and control system 1 for flocs. [Figure 4] FIG. 10 is a diagram specifically illustrating a method for determining an appropriate chemical injection rate X. [Figure 5] 1 is a schematic diagram showing a sludge dewatering apparatus 1B that is a specific example of a solid-liquid separation apparatus 1A that uses a monitoring and control system 1 for flocs. [Figure 6]1A and 1B are photographs of flocs in Example 1 when the amount of flocculant injected is insufficient, appropriate, and excessive. [Figure 7] 10A and 10B are diagrams showing images taken when the state of aggregated flocs is normal and abnormal in Example 2. [Figure 8] 10A and 10B are diagrams showing images taken in cases where the state of aggregated flocs is excessively large, adequately large, and too small in a comparative example. [Figure 9] FIG. 10 is a diagram showing another example of the operation flow of the solid-liquid separator 1A equipped with the monitoring and control system 1 for flocs. [Figure 10] FIG. 10 is an operational flow diagram for setting a drug injection rate within an appropriate range to a rate closer to an under-injection rate. [Figure 11] 10 is a diagram showing an example of determining a rate of change K from a moving average value in the operation flow shown in FIG. 9. FIG. [Figure 12] FIG. 11 is a diagram showing an example of adjusting the chemical injection rate using the operation flow of FIG. 10. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a schematic diagram showing an example of a flocculation control system 1 according to one embodiment of the present invention. As shown in the figure, the flocculation control system 1 is a device that monitors and controls the state of flocs formed in sludge when the sludge is transported from a flocculation / mixing means 10 to a solid-liquid separation means 100. The system is configured to include a sludge supply path 30 that spans between the flocculation / mixing means 10 and the solid-liquid separation means 100 and through which the sludge on which the flocs have formed flows, an imaging means 50 that captures images of the sludge flowing through the sludge supply path 30 from above the water surface, a discrimination means 70 that discriminates the state of floc formation in the sludge based on image information obtained by the imaging means 50, a monitoring means 75 that has functions of confirming and saving the images captured by the imaging means 50 and output values ​​of the image discrimination results, and issuing an alarm, and a flocculant addition amount control means 80 that controls the amount of flocculant added to the flocculation / mixing means 10 in accordance with the state of floc formation discriminated by the discrimination means 70.

[0023] The discrimination means 70, monitoring means 75, and flocculant addition amount control means 80 constitute the control means 90. The flocculation / mixing means 10, solid-liquid separation means 100, and the entire flocculation / floc monitoring and control system 1 constitute the solid-liquid separation apparatus 1A. The discrimination means 70, monitoring means 75, and flocculant addition amount control means 80 may each be located in a personal computer at the site where the flocculation / mixing means 10 or solid-liquid separation means 100 is installed, or may be located in a server on the cloud and discrimination, monitoring, and addition amount control may be performed remotely using an internet connection. The discrimination means 70, monitoring means 75, and flocculant addition amount control means 80 may also be configured on the same personal computer, or one may be configured on a personal computer and the others on a cloud server, and various modifications are possible.

[0024] The flocculation and mixing means 10 is a device that forms flocculated flocs by adding a flocculant to raw sludge (sludge) and stirring it, and is configured by installing an agitator 13 that is driven to rotate by a motor M inside the flocculation and mixing tank 11, and also installing a raw sludge supply pipe 15 that supplies raw sludge into the flocculation and mixing tank 11, and a flocculant supply pipe 17 that supplies a flocculant. A flocculant injection pump P that adjusts the injection amount (injection rate) of the flocculant is attached midway through the flocculant supply pipe 17.

[0025] Raw sludge is the original sludge before the formation of coagulated flocs, and includes sewage sludge (excess sludge, mixed raw sludge, digested sludge), human waste treatment sludge, septic tank sludge, sludge / slurry containing suspended solids such as organic waste, and high-concentration sludge such as oil-containing wastewater. It is sludge with a sludge concentration of 500 mg / L or more, but sludge with a concentration below that is also acceptable.

[0026] The flocculant may be an inorganic flocculant, an organic flocculant, or a combination of an inorganic flocculant and an organic flocculant.

[0027] The solid-liquid separation means 100 is a device that separates solids and liquids from sludge in which flocs have been formed in the flocculation and mixing means 10, and may be any device (means) that separates solids and liquids in sludge, such as a screw press dehydrator, a belt press dehydrator, a thickener (a rotating disk type dewatering device, an elliptical plate type solid-liquid separator [for example, a Slit Saver manufactured by Kendensha Co., Ltd.], pressurized flotation, or atmospheric flotation), as long as it has a configuration in which the flocculation and mixing means 10 is included in the upstream stage.

[0028] The sludge supply path 30 spans between the flocculating and mixing means 10 and the solid-liquid separation means 100, with a slope that descends from the flocculating and mixing means 10 side toward the solid-liquid separation means 100 side, and is configured to allow sludge to flow from the flocculating and mixing means 10 toward the solid-liquid separation means 100. Figure 2 is a schematic cross-sectional view of a main part of the sludge supply path 30 (schematic cross-sectional view taken along line AA in Figure 1). As shown in the figure, the sludge supply path 30 has a trough structure with a U-shaped cross section, and its bottom surface 31 is a horizontal flat surface that extends in a direction perpendicular to the flow direction of the sludge flowing within the sludge supply path 30.

[0029] In this example, the sludge supply path 30 is structured so that the entire path slopes (descends) linearly from the flocculation and mixing means 10 side toward the solid-liquid separation means 100 side, but it may also be configured so that at least a portion of it has a descending section so that the sludge can flow from the flocculation and mixing means 10 toward the solid-liquid separation means 100.

[0030] The inclination angle of the sludge supply path 30 can be changed as desired by an inclination angle adjustment mechanism (not shown). The inclination value is preferably a downward gradient of 5 to 50%, and more preferably a downward gradient of 5 to 35%.

[0031] Here, the relationship between the sludge supply path 30 and the sludge flowing through the sludge supply path 30 will be explained. In this embodiment, the sludge concentration of the raw sludge is set to a high concentration of 500 mg / L or more. In other words, in the case of highly concentrated sludge, coagulated flocs flow densely through the sludge supply path 30. Therefore, in order to configure the sludge supply path 30 so that the coagulated flocs can be properly imaged even in such a case, the inclination angle, width, shape, etc. of the sludge supply path 30 are determined. That is, the width (inner width) L1 of the gutter constituting the sludge supply path 30 is set to 5 to 10 cm or more, and as described above, the gradient of the gutter is set to 5% or more and 50% or less (even 35% or less). Furthermore, as described above, the bottom surface 31 of the sludge supply path 30 is a horizontal, flat surface facing in a direction perpendicular to the flow direction of the sludge flowing through the sludge supply path 30.

[0032] By making the bottom surface 31 a horizontal, flat surface as described above, the depth of the sludge flowing in the sludge supply path 30 is made uniform in each part, and as a result, the state of the aggregated flocs in the image captured by the imaging means 50 from above the water surface is made uniform in each part, improving the accuracy of their identification.

[0033] On the other hand, widening the gutter width slows the linear velocity and simultaneously shallows the water depth, while narrowing it increases the linear velocity and simultaneously deepens the water depth. Furthermore, if the gutter gradient is made smaller, the linear velocity slows down and flocs tend to accumulate on the bottom surface 31, but if it is made too large, the linear velocity becomes too fast and flocs are destroyed on the solid-liquid separation means 100 side.

[0034] Therefore, in this embodiment, as described above, the width (inner width) L1 of the gutter is widened to 5 cm or more to make the water depth shallow, and the bottom surface 31 is flattened as described above to make the flow uniform in each section. As a result, the flocs in the sludge flowing in the gutter do not touch (or are not hidden) each other in the front, back, left, right (toward the water surface) and up and down (in the depth direction), allowing for more accurate detection and identification of the size and quantity of each floc in the image capture. This allows for more appropriate control of the amount of flocculant added to the flocculating and mixing means 10. In other words, the width L1 of the sludge supply channel 30 is set to a width L1 such that, when the sludge flowing in the sludge supply channel 30 is imaged by the imaging means 50, the flocs do not overlap each other (including cases where there is little overlap), at least when the formed flocs are in an appropriate state.

[0035] As described above, the flow rate of the sludge flowing in the sludge supply path 30 varies depending on the gradient of the gutter, but if flocs accumulate on the bottom surface 31 of the gutter, it is not possible to accurately image the state of floc formation, and therefore in this embodiment the gradient (inclination angle) of the gutter is set to 5% or more as an inclination angle at which flocs do not accumulate on the bottom surface 31. If the gradient of the gutter is too large, the flow rate becomes too fast as described above, and flocs are destroyed on the solid-liquid separation means 100 side, so the gradient is set to 50% or less, or further 35% or less.

[0036] The depth of the sludge flowing in the sludge supply path 30 varies depending on the amount of sludge supplied, the width of the gutter, and the gradient of the gutter, but at least when the formed flocs are appropriate, when the sludge flowing in the sludge supply path 30 is imaged by the imaging means 50, it is preferable that the depth be such that the flocs do not overlap each other in the image (including cases where there is little overlap), and in this embodiment it is 5 cm or less.

[0037] In order to remove fouling (suspended matter) such as coagulated flocs, it is preferable to install a cleaning mechanism in the sludge supply path 30 that periodically applies cleaning water to the bottom surface 31 and inner surface of the trough to clean them. In this case, intermittent cleaning is even more preferable.

[0038] As shown in Figures 1 and 2, the imaging means 50 is installed above the sludge supply path 30 and takes an image of the sludge D flowing in the sludge supply path 30 from above the water surface D1, thereby obtaining image information of the flocculated flocs D2 in the sludge D. The image captured by the imaging means 50 is transmitted to the discrimination means 70. The captured image may be a still image or a video image. A portion of the image data input to the discrimination means 70 can be cut out and used for calculation. It can also be input in a compressed form.

[0039] The imaging means 50 is preferably one that can adjust the shutter speed and frame rate in order to photograph the flocs in the flowing sludge. The imaging means 50 may be a monochrome type, but is preferably one that can photograph in color. The lens of the imaging means 50 can be changed as desired. Since flocs may scatter, a transparent plate or filter may be placed between the camera and lens that make up the imaging means 50.

[0040] An illumination means 60 is installed near the imaging means 50 (see FIG. 2). The illumination means 60 illuminates the portion of the sludge D flowing through the sludge supply path 30 that the imaging means 50 is to image. This makes it possible to clearly image the aggregated flocs D2 in the sludge D even if the sludge D has a high degree of turbidity.

[0041] The discrimination means 70 discriminates the state of formation of flocs in the sludge and the chemical injection rate based on the image information transmitted from the imaging means 50. For example, it discriminates the chemical injection rate into three states: "insufficient," "appropriate," and "excessive," and discriminates the state of formation of flocs into "normal," "abnormal," "excessive," "appropriate," "insufficient," etc.

[0042] The discrimination means 70 classifies and discriminates the image information input from the imaging means 50 using an image classification model (image discrimination model, machine learning model) that inputs the image information and outputs the state of the sludge (state of formation of coagulated flocs). Examples of machine learning algorithms include the SVR method (support vector regression), the PLS method (partial least squares), the deep learning method, the random forest method, and the decision tree method. In this embodiment, a deep learning method using a CNN (convolutional neural network) as the network structure is adopted, but the present invention is not limited to this. Image recognition techniques include classification, object detection, and segmentation.

[0043] In this embodiment, classification is adopted, but the present invention is not limited to this. The machine learning method may be supervised learning or unsupervised learning. The input image may be a color still image, or a still image obtained by cutting out a part of video data. Image recognition is performed on the formation state of aggregated flocs in the image information (and turbidity, the same applies below) at a predetermined time interval, for example, once every 20 seconds, and the state (number, size, and area proportion of aggregated flocs) is output as a numerical value.

[0044] The state of floc formation can be determined by image classification, by object detection using the number and size of flocs in the image, or by segmentation using the ratio (area ratio) of the flocculated floc area to the separated water area. Depending on which of these criteria is met, it can be determined whether the amount of flocculant added is insufficient, appropriate, or excessive.

[0045] The constructed machine learning model may be updated periodically (for example, when starting daily driving) or at any timing (for example, when changing driving patterns). The number of machine learning models installed may be one or more (for example, one input image may be discriminated using multiple models, or multiple imaging means 50 may be installed and images captured by each imaging means 50 may be discriminated using a different model). The machine learning model may be constructed by the discrimination means 70, or a machine learning model constructed by another computer may be transplanted into the discrimination means 70.

[0046] Figure 6 shows an example of the state of an image captured by the imaging means 50 (an example of Example 1 described below). The left side shows a state in which the flocs have not been formed to an appropriate size for solid-liquid separation, i.e., a state in which the addition rate (addition amount) of flocculant is too low. The center shows a state in which the flocs have been formed to an appropriate size for solid-liquid separation, i.e., a state in which the addition rate (addition amount) of flocculant is appropriate. The right side shows a state in which the flocs have been formed to a size that is larger than the appropriate size for solid-liquid separation, i.e., a state in which the addition rate (addition amount) of flocculant is excessive.

[0047] In the case of properly flocculated flocs shown in the center, the external shape of each individual floc can be seen and their dimensions can be determined. On the other hand, in the case of insufficiently flocculated flocs shown on the left, the flocs are a collection of fine particles that have not yet fully formed into flocs, and it is unclear to distinguish between the individual unformed flocs or their dimensions. In the case of excessively flocculated flocs shown on the right, the flocs tend to come into contact with each other, making it difficult to see the external shape of each individual floc and their dimensions.

[0048] If the amount of flocculated flocs is insufficient, solid-liquid separation cannot be performed effectively in the subsequent solid-liquid separation means 100. If the amount of flocculated flocs is excessive, this generally means that the chemical injection rate (hereinafter also referred to as "chemical injection rate") is excessive, which increases the chemical cost, and also deteriorates the water content of the dewatered sludge and the solid recovery rate in the subsequent solid-liquid separation step in the subsequent solid-liquid separation means 100, due to the stickiness of the chemical that did not react with the sludge caused by the excess chemical, which deteriorates the gravity filterability and the detachability of the dewatered cake.

[0049] The monitoring means 75 displays and confirms images captured by the imaging means 50 and output values ​​of the discrimination results of the discrimination means 70 on a monitoring screen, and also saves these data. It also issues alarms to the alarm means 77. The monitoring means 75 may be installed on a personal computer as described above, or on a cloud server. In the case of a cloud server, remote monitoring is possible via a network connection such as the Internet. The monitoring screen of the monitoring means 75 can display graphs of images and videos captured by the imaging means 50 and output results, graphs calculated from the output results, graph legends, alarms, control thresholds, and the like. The monitoring means 75 can also perform calculations using the output results (such as moving averages of output results, weighting by multiplying with a coefficient, or obtaining a majority vote of multiple output results).

[0050] The alarm means 77 may be installed on-site where the solid-liquid separation means 100 and the like are installed, or may be installed in a central control room, or may be installed in a mobile terminal carried by an operator or the like. The alarm may be issued by voice, light, text (email), sound, or any other means that appeals to the five senses. In this example, the alarm notification to the alarm means 77 is configured to be sent from the monitoring means 75, but it may also be sent from another device of the control means 90 (such as the discrimination means 70).

[0051] The flocculant addition amount control means 80 controls the amount of flocculant added to the flocculating / mixing means 10 depending on the state of floc formation determined by the determination means 70. That is, if the determination result of the determination means 70 is "appropriate," the operation of the flocculant injection pump P is maintained so as to maintain the current flocculant addition rate (amount added). If the determination result of the determination means 70 is "too low," the flocculant injection pump P is operated so as to increase the flocculant addition rate (amount added). If the determination result of the determination means 70 is "excessive," the flocculant injection pump P is operated so as to decrease the flocculant addition rate (amount added). In this embodiment, the following method is used as a method for controlling the flocculant addition rate (amount added) to an appropriate addition rate (amount added).

[0052] 3 is a diagram showing an example of the operation flow of the solid-liquid separation apparatus 1A equipped with the above-mentioned flocculation control system 1. When starting operation of the solid-liquid separation apparatus 1A, first, the chemical feeding rate (chemical injection rate) of the flocculant supplied to the flocculation mixing tank 10 is set to a predetermined chemical feeding rate X (step 1-1), and then the operation of the flocculation mixing means 10 and the solid-liquid separation means 100 is started (step 1-2). At the same time, the rate of change K of the chemical feeding rate X is set to 0.5 pt (step 1-3) and stored.

[0053] Here, the chemical feeding rate (%) means the amount of chemical per sludge volume (unit: g), and is calculated using the following formula: Chemical dosing rate (%) = [[Chemical dissolution concentration (%) × Chemical supply amount (m 3 ) / [Sludge concentration (%) x sludge supply amount (m 3 )] x 100 It is expressed as:

[0054] That is, the agitator 13 is driven by the motor M to agitate the raw sludge introduced into the flocculation mixing tank 11, and at the same time, the flocculant injection pump P is driven in response to a command from the flocculant addition amount control means 80 so that the chemical feeding rate becomes X. As a result, flocs are formed in the sludge in the flocculation mixing tank 11, and the sludge with the flocs formed thereon flows through the sludge supply path 30 and is introduced into the solid-liquid separation means 100. The sludge introduced into the solid-liquid separation means 100 is separated into a solid fraction and a liquid fraction.

[0055] Here, the sludge flowing through the sludge supply path 30 is imaged by the imaging means 50 (step 1-4), and the image information is transmitted to the discrimination means 70. The imaging area of ​​the sludge supply path 30 by the imaging means 50 must be an area that allows the state of the flocs and separated water to be discriminated in an image or video, and is set to 25 cm 2 It is desirable that the distance is 100cm or more to improve the accuracy of image classification. 2 More preferably, it is equal to or greater than this.

[0056] Furthermore, if the amount of sludge containing flocs supplied relative to the width dimension L1 of the gutter that constitutes the sludge supply path 30 is too great, the depth of the sludge flowing through the gutter will increase, and the flocs will overlap each other. Conversely, if the amount is too small, even if the appropriate amount of flocs has been formed, the flocs will not flow smoothly and will accumulate at the bottom, causing blockages. Therefore, as mentioned above, it is desirable to keep the depth of the sludge when it is supplied to the gutter to 5 cm or less, and more preferably 3 cm or less. However, as mentioned above, if the water depth is too shallow, there is a risk that the flocs will accumulate, so the width and gradient of the gutter relative to the amount of sludge supplied are determined so as to achieve a predetermined water depth that will not cause accumulation.

[0057] The discrimination means 70 discriminates the state of formation of coagulated flocs in the sludge (step 1-5), and if it is "appropriate", it moves from "Y" in step 1-5 to step 1-6, and since no alarm is currently being issued, it moves directly to step 1-7 (skips), and since operation continues, it returns to step 1-3 via "N" in step 1-7 and repeats the above steps.

[0058] Here, the sludge supply path 30 through which the sludge on which flocs have formed flows has a trough structure, so even if the turbidity concentration is high like sludge, the formed flocs can be easily identified from above the water surface. This improves the accuracy of identifying flocs by the image capture screen from above the water surface by the imaging means 50, and enables appropriate control of the amount of flocculant added to the flocculating and mixing means 10.

[0059] On the other hand, if the state of floc formation in the sludge is determined to be "inappropriate" in step 1-5, the process moves from "N" in step 1-5 to step 1-8, and after an alarm is issued, the appropriate chemical dosing rate X is determined using the following method.

[0060] That is, in step 1-9, it is determined whether the discrimination result is "excessive" or "insufficient." If it is "excessive," the chemical dosing rate X is decreased by the change rate K (=0.5 pt) (step 1-10). If it is "insufficient," the chemical dosing rate X is increased by the change rate K (=0.5 pt) (step 1-11). The chemical dosing rate X is changed to these increased or decreased values, and the coagulant addition amount control means 80 drives the coagulant injection pump P at the new chemical dosing rate X.

[0061] Then, operation is carried out at this changed chemical feeding rate X for a predetermined time (the time until the formation state of the aggregated flocs at the changed chemical feeding rate X stabilizes, in this example, 5 minutes), and then the rate of change K is changed to half, 0.25 pt (step 1-12), and the process returns to step 1-4.

[0062] In steps 1-4 and 1-5, the image information captured by the imaging means 50 is again discriminated by the discrimination means 70, and if it is "appropriate", the process proceeds from "Y" in step 1-5 to step 1-6, the alarm is cleared, and then the process returns to step 1-4 via "N" in step 1-7, and the above steps are repeated. That is, the operation of the solid-liquid separation apparatus 1A continues at the new chemical feeding rate X.

[0063] On the other hand, if the state of floc formation in the sludge is still determined to be "inappropriate" in step 1-5, the process proceeds from "N" in step 1-5 to step 1-8, where the alarm continues to be issued. In step 1-9, it is determined whether the determination result is "excessive" or "insufficient." If it is "excessive," the chemical dosing rate X is decreased by the change rate K (=0.25 points) (step 1-10). If it is "insufficient," the chemical dosing rate X is increased by the change rate K (=0.25 points) (step 1-11). The chemical dosing rate X is changed to the increased or decreased value, and the coagulant addition amount control means 80 drives the coagulant injection pump P at the new chemical dosing rate X. Operation is performed using this changed chemical dosing rate X for a predetermined time (5 minutes), after which the change rate K is halved to 0.13 points (step 1-12), and the process returns to step 1-4. The above operation is repeated until the determination result in step 1-5 is "appropriate."

[0064] Figure 4 is a diagram specifically illustrating how to determine the appropriate chemical dosing rate X using the above method. For example, if the process proceeds from steps 1-1, 2, 3, and 4 to step 1-5, and the current chemical dosing rate X is point (1), and the appropriate chemical dosing rate X at that time is the chemical dosing rate X at point (4), then step 1-5 will result in inappropriate "N," so the process proceeds to steps 1-8 and 1-9. The determination result of step 1-9 will be insufficient "N," so the process proceeds to step 1-11, where the chemical dosing rate X is increased by the change rate K (=0.5 pt), and after 5 minutes have passed, the change rate K (=0.25 pt) is set in step 1-12, and the process returns to step 1-4. At this time, the chemical dosing rate X is point (2) as shown in Figure 5.

[0065] Next, since the result of step 1-5 is inappropriate "N", the process proceeds to steps 1-8 and 1-9, and since the result of step 1-9 is excessive "Y", the process proceeds to step 1-10, where the chemical dosing rate X is decreased by K (=0.25 points), and after 5 minutes have passed, the change rate is set to K (=0.13 points) in step 1-12, and the process returns to step 1-4. At this time, the chemical dosing rate X is at point (3) shown in Figure 5.

[0066] Next, since the result of step 1-5 is inappropriate "N", the process proceeds to steps 1-8 and 1-9, and since the result of step 1-9 is excessive "Y", the process proceeds to step 1-10, where the chemical dosing rate X is decreased by K (=0.13 pt), and after 5 minutes have passed, the change rate is set to K (=0.07 pt) in step 1-12, and the process returns to step 1-4. At this time, the chemical dosing rate X reaches point (4) in Figure 5, which is the appropriate chemical dosing rate X.

[0067] Next, since the result of step 1-5 is appropriate "Y", the process proceeds to step 1-6, and after the alarm is stopped, the process proceeds from "N" in step 1-7 to step 1-3, where the rate of change K is returned to 0.5 pt, and the current dosing rate X is maintained until the judgment result in step 1-5 becomes inappropriate "N" (steps 1-3 to 1-7 are repeated).

[0068] When the above method is used to obtain an appropriate drug injection rate, the number of times the drug injection rate needs to be changed is reduced, and it is possible to reach the appropriate drug injection rate in a shorter time than when the appropriate drug injection rate is obtained by gradually increasing or decreasing the drug injection rate.

[0069] Furthermore, when an appropriate chemical dosing rate is determined by gradually increasing or decreasing the chemical dosing rate, the amount of change in each dosing rate change is small, and the change in the flocculated flocs after each change is also small, making it difficult to determine whether the appropriate state has been reached (there are more cases where the chemical dosing rate X is at the extreme end of the range of chemical dosing rates X that are determined to be appropriate, and in such cases it is difficult to determine whether the state is appropriate). However, by using the above method, the amount of change in the chemical dosing rate can be made large, and the change in the flocculated flocs after each change is also large, making it easier to determine whether the appropriate state has been reached.

[0070] For example, if there is a large amount of foam in the sludge in the image captured by the imaging means 50 in step 1-4, an antifoaming agent may be added. The antifoaming agent may be added in the flocculation / mixing means 10, the sludge supply path 30, or the flocculating agent supply pipe 17. The residence time from the injection point of the antifoaming agent to the photographing of the flocculated flocs is preferably 10 to 15 seconds or more, at which time the antifoaming effect is apparent.

[0071] As described above, the flocculation control system 1 includes the sludge supply path 30 having a trough structure that extends from the flocculation and mixing means 10 toward the solid-liquid separation means 100 at a downward incline and allows sludge on which flocs have formed to flow to be passed; the imaging means 50 that takes images of the sludge flowing in the sludge supply path 30 from above the water surface to obtain image information of the flocs in the sludge; the discrimination means 70 that discriminates the state of floc formation based on the image information obtained by the imaging means 50; and the flocculant addition amount control means 80 that controls the amount of flocculant to be added to the flocculation and mixing means 10 in accordance with the state of the flocs discriminated by the discrimination means 70. Therefore, even in sludge with a high turbidity concentration, such as sludge, the formed flocs can be identified from above the water surface of the sludge flowing in the trough that constitutes the sludge supply path 30. This improves the accuracy of identifying flocs by the imaging means 50 and enables appropriate control of the amount of flocculant to be added to the flocculation and mixing means 10.

[0072] Furthermore, according to the above-mentioned flocculation monitoring and control system 1, the bottom surface 31 of the inclined sludge supply channel 30 is made into a horizontal flat surface in a direction perpendicular to the flow direction of the sludge flowing through the sludge supply channel 30, so that the depth of the sludge can be maintained uniform in the width direction, the accuracy of identifying flocculation flocs in the image captured by the imaging means 50 from above the water surface D1 can be further improved, and more appropriate control of the amount of flocculant added to the flocculation and mixing means 10 can be performed.

[0073] Furthermore, according to the above-described floc monitoring and control system 1, the width dimension L1 of the sludge supply path 30 is set to a predetermined width dimension L1 such that, when the sludge flowing through the sludge supply path 30 is imaged by the imaging means 50, the flocs in the image do not overlap (there is little overlap), at least when the flocs are in an appropriate state. This allows the dimensions and quantity of each floc to be accurately determined, further improving the accuracy of identifying flocs in the image captured by the imaging means 50, and enabling more appropriate control of the amount of flocculant added to the flocculating and mixing means 10.

[0074] Furthermore, according to the above-described floc monitoring and control system 1, the inclination angle of the sludge supply path 30 is set to an angle equal to or greater than the angle at which flocs in the sludge flowing through the sludge supply path 30 do not remain on the bottom surface 31, so that the flocs in the sludge can be reliably carried away along with the flow of the sludge, thereby further improving the accuracy of identifying the flocs.

[0075] In the above example, an alarm is issued when the discrimination means 70 determines that the condition is not "appropriate." However, the configuration may also be such that an alarm is issued when an abnormality occurs, such as when the amount of flocculant cannot be controlled to achieve an appropriate floc state even when adjusted using the above method.

[0076] Next, an example and a comparative example of the above-described floc monitoring and control system 1 will be described. Example 1: The experiment was carried out under the following conditions: Target sludge: human waste treatment sludge (9000mg / L) Flocculant: Polymer flocculant Procedure: The injection rate of polymer flocculant was increased and decreased, and images of flocculated flocs were taken when the amount of flocculant injected was too little, too much, and appropriate. The images are shown in Figure 6. Sludge supply channel 30 trough structure: width (L1) 60cm, floc-containing sludge supply volume 12m 3 / h, gradient 5%, water depth 5cm Algorithm used to build machine learning models: CNN (convolutional neural network) Result: Correct answer rate 0.89

[0077] Example 2: The experiment was carried out under the following conditions: Target sludge: Primary sludge (4300mg / L), excess sludge (4400mg / L), mixed sludge (4600mg / L) Flocculant: Polymer flocculant Operation: The injection rate of polymer flocculant was increased and decreased, and images of flocs in normal and abnormal states were taken. The images are shown in Figure 7. Sludge supply channel 30 trough structure: width (L1) 50cm, floc-containing sludge supply volume 10m 3 / h, gradient 5%, water depth 3cm Algorithm used to build machine learning models: CNN (convolutional neural network) Result: Accuracy rate 0.95

[0078] Comparative Example: The experiment was carried out under the following conditions: Target sludge: digested sludge (10,000 mg / L) Flocculant: Polymer flocculant Operation: The injection rate of polymer flocculant was increased and decreased, and photographs of the flocs were taken when the flocs were too large, too small, and in the appropriate floc state. The photographed images are shown in Figure 8. Sludge supply channel 30 trough structure: width (L1) 60 cm, floc-containing sludge supply volume 1.3 m 3 / h, gradient 1%, water depth 6cm Algorithm used to build machine learning models: CNN (convolutional neural network) Result: Accuracy rate 0.74

[0079] conclusion In the above Examples 1 and 2, by using an appropriate gutter structure (width 50 to 60 cm, gradient 5%, and water depth 3 to 5 cm), overlapping of the flocs to be photographed was suppressed, making it easier to distinguish the different appearances of the flocs, and thus improving the accuracy of image discrimination.

[0080] On the other hand, in the comparative example, the slope of the gutter (1%) was gentle and the depth of the sludge flowing through the gutter (6 cm) was deep, so it was not possible to prevent the flocs being photographed from overlapping, making it difficult to distinguish the state of each floc, and the accuracy of image discrimination was low.

[0081] Figure 5 is a schematic diagram of a sludge dewatering apparatus 1B, which is one specific example of the solid-liquid separation apparatus 1A. In this figure, parts that are the same as or equivalent to those of the solid-liquid separation apparatus 1A shown in Figure 1 are given the same reference numerals (with the addition of "B"), and detailed explanations thereof will be omitted. Note that matters other than those explained below are the same as those in the embodiment shown in Figures 1 to 4.

[0082] As shown in the figure, the sludge dewatering apparatus 1B is configured to include a flocculation and mixing means 10B, a monitoring and control system 1 for the flocculation (sludge supply path 30B, imaging means 50B, and control means 90B), a solid-liquid separation means (hereinafter referred to as "concentrator") 100B, and a separated liquid tank 130B.

[0083] The flocculating and mixing means 10B has a configuration equivalent to that of the flocculating and mixing means 10 shown in Fig. 1. The configurations of the sludge supply path 30B and the imaging means (hereinafter referred to as "first imaging means") 50B that constitute the flocculated floc monitoring and control system 1 are also equivalent to the configurations of the sludge supply path 30 and the imaging means 50 shown in Fig. 1.

[0084] The concentrator 100B is a concentrator configured so that solids (sludge) are transported on rotating elliptical plates, and separated from the liquid by dropping a separated liquid between the plates. A second imaging means 101B is installed in a position to capture an image of the state of the solids (sludge) from above as it is transported on the elliptical plates. The separated liquid (separated liquid) is collected at the bottom of the concentrator 100B and stored in a separated liquid tank 130B. A third imaging means 131B is installed in the separated liquid tank 130B in a position to capture an image of the state of the separated liquid stored therein.

[0085] The images captured by the first, second, and third imaging means 50B, 101B, and 131B are transmitted to the control means 90B. In addition to the functions of the control means 90 (such as the discrimination means 70, monitoring means 75, and flocculant addition amount control means 80) shown in Fig. 1, the control means 90B has at least a discrimination means for discriminating the image captured by the second imaging means 101B, a discrimination means for discriminating the image captured by the third imaging means 130B, and an operation control means for controlling the operation of the concentrator 100B using the discrimination results of the discrimination means for the second and third imaging means 101B and 131B.

[0086] The image captured by the second imaging means 101B is used by a discrimination means to determine the state of the concentrated sludge (such as the moisture content) using machine learning.The image captured by the third imaging means 131B is used by a discrimination means to determine the state of the separated liquid (such as the number and area of ​​flocs that could not be separated in the separated liquid, and the degree of turbidity and color of the separated liquid) using machine learning.Using both of these discrimination results, the operating state of the concentrator 100B (such as the rotation speed of the elliptical plate) is controlled using an operation control means.

[0087] That is, the sludge dewatering apparatus 1B introduces raw sludge into the flocculation mixing tank 11B, and simultaneously drives the motor M to rotate the agitator 13B in response to a control signal from the control means 90B, and controls the operation of the flocculant injection pump P in response to a control signal from the control means 90B, thereby supplying flocculant to the flocculation mixing tank 11B at a predetermined chemical feeding rate. As a result, flocs are formed in the flocculation mixing tank 11B, and the sludge with the flocs formed therein is flowed into the sludge supply path 30, its state is imaged by the first imaging means 50B, and as described above, the image data is sent to the control means 90B, which determines the chemical feeding rate and controls the flocculant injection pump P so as to achieve the determined chemical feeding rate. In this way, sludge with appropriate flocs formed therein can be introduced into the thickener 100B.

[0088] The sludge introduced into the concentrator 100B undergoes solid-liquid separation, during which the state of the sludge is imaged by the second imaging means 101B and the image data is sent to the control means 90B. Meanwhile, the separated liquid after solid-liquid separation in the concentrator 100B is discharged into the separated liquid tank 130B, during which the state of the separated liquid is imaged by the third imaging means 131B and the image data is sent to the control means 90B.

[0089] The imaging data obtained by the second and third imaging means 101B, 131B is discriminated by each discrimination means within the control means 90B, and if it is determined that the solid-liquid separation state is not appropriate, the control means 90B performs control such as changing the operating state of the concentrator 100B, for example, the rotation state of the elliptical plate.

[0090] That is, for example, even if the imaging data obtained by the third imaging means 131B indicates that there are a large or small number of unseparated flocs, as long as the flocculating floc monitoring and control system 1 is adding flocculant at an appropriate dosage rate, it is clear that the cause lies not in the flocculant dosage rate but in the concentrator 100B, and the operation of the concentrator 100B can be controlled. Of course, the imaging data obtained by the second and third imaging means 101B, 131B may also be used to control the amount of flocculant added.

[0091] In other words, since the amount of flocculant to be added can be appropriately controlled mainly by the first imaging means 50B, etc., and appropriate flocculated flocs can be formed, the information obtained by the second imaging means 101B and / or the third imaging means 131B does not need to be used to adjust the amount of flocculant to be added, and can be used mainly to control the operation of the concentrator 100B, thereby allowing for more appropriate solid-liquid separation in the sludge dewatering apparatus 1B.

[0092] Furthermore, for example, when the imaging data obtained by the third imaging means 131B indicates that there are a large or small number of flocs that could not be separated, and the flocculation monitoring and control system 1 determines that the flocculant is inappropriate and changes the chemical feeding rate, the operating state of the concentrator 100B may be maintained as is until the chemical feeding rate becomes appropriate, and the operating state of the concentrator 100B may be changed after the flocculation monitoring and control system 1 determines that the flocculation agent is appropriate. In this way, it is preferable that the control means 90B controls the control of the flocculation monitoring and control system 1 and the operation control of the condenser 100B in a mutually associated manner.

[0093] In the above-mentioned sludge dewatering apparatus 1B, two imaging means, the second imaging means 101B and the third imaging means 131B, are installed to capture images of the respective states of the solid-liquid separated sludge and separated liquid, but the state of solid-liquid separation may be detected by installing only one of them.

[0094] Next, another example of the operation flow of the solid-liquid separator 1A will be described. In the operation flow of the solid-liquid separation apparatus 1A shown in FIG. 3, an example has been described in which the change rate K is halved in step 1-12 in order to change the chemical feeding rate X to an appropriate state. However, in this operation flow, instead, the change rate K is set to a value corresponding to the output result of the discrimination means 70.

[0095] 9 is a diagram showing another example of the operation flow of the solid-liquid separation apparatus 1A equipped with the above-described flocculation control system 1. In the operation flow shown in the figure, the same procedure as the operation flow described using FIG. 3 is followed: first, the dosing rate of the flocculant to be supplied to the flocculation mixing tank 10 is set to a predetermined dosing rate X (step 2-1), and then the operation of the flocculation mixing means 10 and the solid-liquid separation means 100 is started (step 2-2). Next, the sludge flowing through the sludge supply path 30 is imaged by the imaging means 50 (step 2-3), and the image information is sent to the discrimination means 70.

[0096] The discrimination means 70 discriminates the state of formation of coagulated flocs in the sludge (step 2-4), and if it is "appropriate", operation continues as is (from "Y" in step 2-4, skip step 2-5, go through "N" in step 2-6 and return to step 2-3, and repeat the above steps).

[0097] On the other hand, if the state of floc formation in the sludge is determined to be "inappropriate" in step 2-4, the process moves from "N" in step 2-4 to step 2-7, and after an alarm is issued, the appropriate chemical dosing rate X is determined using the following method.

[0098] That is, in step 2-8, it is determined whether the discrimination result is "excessive" or "insufficient," and if it is "excessive" ("Y" in step 2-8), the rate of change K according to the output value of the discrimination means 70 is determined and set (step 2-9). The rate of change K to be determined at this time is determined based on the moving average of the output value of the formation state of the flocs output by the discrimination means 70 or the output probability value.

[0099] Here, the moving average of the output value refers to the average value of the classification results for images taken over a specified period of time (e.g., 3 minutes) in order to increase the reliability of the image classification results using machine learning, etc., and the output probability value refers to an index of the degree of reliability of the classification results calculated by the machine learning algorithm.

[0100] Specifically, the rate of change K is determined based on the table shown in FIG. 11. In this example, if the moving average value is assumed to be between 0.25 and 0.75, and the moving average value is significantly higher, for example, at 0.9 or higher, the rate of change K is set to 0.4 pt; if the moving average value is moderately high, the rate of change K is set to 0.3 pt; and if the moving average value is not so high, the rate of change K is set to 0.2 pt. This results in the rate of change K corresponding to the output of the determination means 70. Then, in step 2-10, the chemical dosing rate X is reduced by the rate of change K, and the chemical dosing rate X is changed to this reduced value. The coagulant addition amount control means 80 drives the coagulant injection pump P at the new chemical dosing rate X.

[0101] On the other hand, if the result is "insufficient" ("N" in step 2-8), the process proceeds to step 2-11, where the rate of change K is calculated and set according to the output value of the discrimination means 70. The rate of change K calculated here is determined based on the moving average of the output values ​​of the floc formation state output by the discrimination means 70 or the output probability value. Specifically, based on the table shown in FIG. 11, for example, if the moving average value is significantly low, such as 0.1 or more, the rate of change K is set to 0.4 pt; if it is moderately low, the rate of change K is set to 0.3 pt; and if it is not so low, the rate of change K is set to 0.2 pt. Then, in step 2-12, the chemical dosing rate X is increased by the rate of change K, and the chemical dosing rate X is changed to this increased value. The coagulant addition amount control means 80 drives the coagulant injection pump P at the new chemical dosing rate X. Using the above operation flow, an appropriate chemical injection rate can be achieved in a short time.

[0102] Next, we will explain the operational flow for adjusting the drug injection rate to be further under-adjusted even though the drug injection rate is appropriate within the appropriate range. Figure 10 is an operational flow diagram for when the state "Y" remains in step 1-5 of Figure 3, that is, when the drug injection rate is continuously maintained within the appropriate range, but is set to be further under-adjusted within that appropriate range.

[0103] The operation flow of Fig. 10 is inserted, for example, between steps 1-5 to 1-7 of Fig. 3. Fig. 12 is a diagram showing an example of adjusting the chemical injection rate using the operation flow of Fig. 10.

[0104] In this example, the appropriate range is set to 0.25 to 0.75 as the moving average value of the output of the discrimination means 70, the range A where the chemical injection rate X is excessive is set to 0.6 to 0.75, and the range B where the chemical injection rate X is insufficient is set to 0.3 to 0.6. The rate of change X is also set to a small value of 0.1 pt.

[0105] First, in step 3-1, if the discrimination result (moving average value of output) of the discrimination means 70 is maintained at 0.6 or more and less than 0.75 (i.e., in the excessive range A) for 15 minutes, i.e., for a certain period of time ("Y" in step 3-1), the chemical injection rate X is reduced by the change rate K (=0.1 pt) (step 3-2).

[0106] Next, after a predetermined time (e.g., 5 minutes) has elapsed, if the judgment result of the discrimination means 70 is greater than 0.6 ("Y" in step 3-3), the process returns to step 3-2 and further reduces the dosing rate X by the change rate K (=0.1 pt); on the other hand, if the judgment result of the discrimination means 70 is less than 0.6 ("N" in step 3-3), the process proceeds to step 3-4.

[0107] In step 3-4, if the discrimination result of the discriminating means 70 is in the under-range B of 0.3 or more and less than 0.6, the state is maintained as it is ("Y" in step 3-4).

[0108] On the other hand, in step 3-4, if the discrimination result of the discrimination means 70 is less than 0.3, which is below the range B on the under-level side ("N" in step 3-4), the drug dosing rate X is increased by the change rate K (=0.1 pt) (step 3-5), and the increase in the drug dosing rate is repeated until the moving average value of the output of the discrimination means 70 falls into the range on the under-level side (0.3 or more) ("N" in step 3-6).

[0109] Figure 12 is a diagram showing an example of adjusting the chemical injection rate according to the operation flow shown in Figure 10. In this figure, the horizontal axis represents time, and the vertical axis represents the discrimination result (moving average value of the output of the discrimination means 70). The appropriate range of the discrimination result is 0.25 to 0.75, but in this example, the discrimination result for issuing an alarm is 0.85 or more and 0.2 or less. This is because if an alarm is issued immediately when the appropriate range is exceeded, the number of alarms may increase too much.

[0110] In Figure 12, if the discrimination result remains at or above 0.6 for 15 minutes, although it is within the appropriate range, then at point (1), the chemical dosing rate X is reduced by the change rate K (= 0.1 pt). Five minutes later, at point (2), the discrimination result is still at or above 0.6, so the chemical dosing rate X is further reduced by the change rate K (= 0.1 pt). Five minutes later, at point (3), the discrimination result is still at or above 0.6, so the chemical dosing rate X is further reduced by the change rate K (= 0.1 pt). Five minutes later, at point (4), the discrimination result is between 0.3 and 0.6, so the chemical dosing rate X maintains its current value. According to this operation flow, the chemical injection rate can be kept low, which leads to cost reduction.

[0111] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications are possible within the scope of the claims and the technical concept described in the specification and drawings. Furthermore, any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical concept of the present invention as long as it achieves the functions and effects of the present invention. For example, in the above embodiment, an example was shown in which all of the sludge containing the flocculated flocs formed by the flocculating and mixing means 10 was flowed into the sludge supply path 30. However, a configuration may also be adopted in which a portion of the sludge containing the flocculated flocs formed by the flocculating and mixing means 10 is flowed into the sludge supply path 30 and photographed by the imaging means 50, and the remaining sludge containing the flocculated flocs is transported to the solid-liquid separation means 100 via a different route.

[0112] Furthermore, the embodiments described above and shown in the drawings can be combined with each other as long as there is no contradiction in their purpose, configuration, etc. Furthermore, even a part of the description described above and the drawings can be an independent embodiment, and the embodiment of the present invention is not limited to a single embodiment combining the description described above and the drawings. [Explanation of symbols]

[0113] 1...Flocculation floc monitoring and control system, 1A...Solid-liquid separation device, 10...Flocculation and mixing means, 11...Flocculation and mixing tank, M...Motor, P...Flocculant injection pump, 13...Agitator, 15...Raw sludge supply pipe, 17...Flocculant supply pipe, 30...Sludge supply path, 31...Bottom, L1...Width dimension, 50...Imaging means, 70...Discrimination means, 75...Monitoring means, 77...Alarm means, 80...Flocculant addition Quantity control means, 90...control means, 100...solid-liquid separation means, D...sludge, D1...water surface, D2...coagulated flocs, 1B...sludge dewatering device, 10B...coagulation mixing means, 50B...first imaging means, 90B...control means, 100B...solid-liquid separation means (concentrator), 101B...second imaging means, 130B...separation liquid tank, 131B...third imaging means, X...chemical injection rate (chemical injection rate), K...change rate.

Claims

1. 1. A monitoring and control system for flocculated flocs, which monitors and controls the state of the flocs when the sludge on which the flocs have been formed is transferred from a flocculation and mixing means that adds a flocculant to sludge and stirs the sludge, to a solid-liquid separation means that separates the sludge into solid and liquid, a sludge supply path having a trough structure that spans between the flocculating and mixing means and the solid-liquid separation means, and that has at least a portion that is inclined downward from the flocculating and mixing means toward the solid-liquid separation means, through which the sludge on which the flocs have formed flows; an imaging means for capturing an image of the sludge flowing through the sludge supply path from above the water surface to obtain image information of the flocs in the sludge; A monitoring and control system for flocculation, comprising:

2. The flocculation monitoring and control system according to claim 1, a discrimination means for discriminating the formation state of the flocs based on the image information obtained by the imaging means; a flocculant addition amount control means for controlling the amount of flocculant to be added to the flocculation mixing means in accordance with the state of floc formation determined by the determination means; A monitoring and control system for flocculation, further comprising:

3. The monitoring and control system for flocculation according to claim 1 or 2, The bottom surface of the inclined sludge supply channel is a flat surface that is horizontal in a direction perpendicular to the flow direction of the sludge flowing through the sludge supply channel. A monitoring and control system for flocculation.

4. The monitoring and control system for flocculation according to claim 1 or 2, The width dimension of the sludge supply path is equal to or greater than a predetermined width dimension such that, when the sludge flowing through the sludge supply path is imaged by the imaging means, the flocs in the image do not overlap with each other, at least when the flocs are in an appropriate state. A monitoring and control system for flocculation.

5. The monitoring and control system for flocculation according to claim 1 or 2, The inclination angle of the sludge supply path is equal to or greater than the inclination angle at which flocs in the sludge flowing through the sludge supply path do not accumulate on the bottom surface. A monitoring and control system for flocculation.

6. The monitoring and control system for flocculation according to claim 1 or 2, The depth of the sludge flowing through the sludge supply path is set to a predetermined depth or less at which, when the sludge flowing through the sludge supply path is imaged by the imaging means, the flocs in the image do not overlap with each other, at least when the flocs are in an appropriate state. A monitoring and control system for flocculation.

7. The flocculation monitoring and control system according to claim 2, The flocculant addition amount control means A chemical injection rate X of the flocculant and a rate of change K by which the chemical injection rate X is increased or decreased are determined in advance, When the determination means determines that the chemical injection rate X of the flocculant is appropriate based on the state of flocculation floc formation during operation at the chemical injection rate X of the flocculant, the chemical injection rate X of the flocculant is maintained, On the other hand, if it is determined from the state of formation of flocculated flocs by the discrimination means when operating at the chemical injection rate X of the flocculant that the chemical injection rate X of the flocculant is excessive, the chemical injection rate X is reduced from the chemical injection rate X by the change rate K to set a new chemical injection rate X, and on the other hand, if it is determined that the chemical injection rate X of the flocculant is insufficient, the chemical injection rate X is increased from the chemical injection rate X by the change rate K to set a new chemical injection rate X, and when changing to the new chemical injection rate X, the change rate K is halved to set a new change rate K; this process is repeated until it is determined that the chemical injection rate X of the flocculant is appropriate. A monitoring and control system for flocculation.

8. The flocculation monitoring and control system according to claim 2, The flocculant addition amount control means The chemical injection rate X of the flocculant is determined in advance, When the determination means determines that the chemical injection rate X of the flocculant is appropriate based on the state of flocculation floc formation during operation at the chemical injection rate X of the flocculant, the chemical injection rate X of the flocculant is maintained, On the other hand, if it is determined that the chemical injection rate X of the flocculant is excessive based on the state of flocculation floc formation determined by the discrimination means when the system is operated at the chemical injection rate X of the flocculant, a rate of increase K by which the chemical injection rate X is increased is determined based on the degree of flocculation floc formation determined by the discrimination means, and the chemical injection rate X is reduced from the chemical injection rate X by the rate of change K to set a new chemical injection rate X; on the other hand, if it is determined that the chemical injection rate X of the flocculant is insufficient, a rate of decrease K by which the chemical injection rate X is reduced is determined based on the degree of flocculation floc formation determined by the discrimination means, and the chemical injection rate X is increased from the chemical injection rate X by the rate of change K to set a new chemical injection rate X; and operation at the new chemical injection rate X is repeated until it is determined that the chemical injection rate X of the flocculant is appropriate. A monitoring and control system for flocculation.

9. The flocculation monitoring and control system according to claim 2, The flocculant addition amount control means A chemical injection rate X of the flocculant and a rate of change K by which the chemical injection rate X is reduced are determined in advance, If the moving average of the output value of the floc formation state by the discrimination means when operating at the chemical injection rate X of the flocculant continues to be within a predetermined range A that is closer to excessive within the appropriate range for a certain period of time, the chemical injection rate X is changed to a new chemical injection rate X that is obtained by reducing the chemical injection rate X by the change rate K, and this is repeated until the moving average is determined to be within a predetermined range B that is closer to insufficient than the predetermined range A within the appropriate range, On the other hand, if the result of the repetition is that the chemical injection rate X of the flocculant is determined to be less than the predetermined range B on the under-injection side, the chemical injection rate X is changed to a new chemical injection rate X by increasing the chemical injection rate X by the change rate K. This is repeated until the chemical injection rate X is determined to be less than the predetermined range B on the under-injection side. A monitoring and control system for flocculation.

10. a flocculating and mixing means for adding a flocculant to the sludge and stirring the sludge to flocculate the sludge and form flocs; a solid-liquid separation means for separating the sludge in which the flocs have formed into solid and liquid; In a sludge dewatering apparatus having The floc monitoring and control system according to claim 1 or 2; a second imaging means for obtaining image information of the sludge separated by the solid-liquid separation means or a third imaging means for obtaining image information of the state of the separated liquid separated by the solid-liquid separation means; an operation control means for controlling the operation of the solid-liquid separation means using image information of the sludge taken by the second imaging means or image information of the state of the separated liquid taken by the third imaging means; and A sludge dewatering apparatus comprising:

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