JP5271942B2 - Sludge treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sludge treatment apparatus and a sludge treatment method adjusting an amount of addition of a coagulant and the rotation speed of a coagulant agitator by imaging the coagulation state of flock in sludge raw liquid. <P>SOLUTION: The sludge treatment apparatus includes: an imaging part 11 imaging the coagulated flock passing through a sludge raw water feed pipe 33; a conversion part 18 binarizing the image of the coagulated flock imaged by the imaging part 11 and forming a binary image; a calculation part 13 calculating a reference area of the coagulated flock based on the measured area of the coagulated flock that is the area of the coagulated flock displayed on the binary image formed by the conversion part 18 and an initial coagulant adding rate set in advance; a comparing part 14 comparing the measured area of the coagulated flock with the reference area of the coagulated flock; a control part 15 controlling the rotation speeds of a coagulant feed pump 29 and the coagulant agitator 21 according to the comparison result by the comparing part 14; and an output part 16 generating an alarm according to the comparison result by the comparing part 14. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention, clean water sludge, based on the aggregated state of flocs contained in the sludge concentrate of such sewage sludge and industrial wastewater sludge, to sludge treatment how to control the rotational speed of the flocculant addition rate and stirrer.

  The agglomeration treatment of sludge generated from the water treatment process is a pre-stage process for efficiently treating the sludge, and is a step of agglomerating suitable for dehydration by adding a flocculant to the sludge. If the state of sludge aggregation in this coagulation treatment step is good, the water content of the sludge after dehydration can be reduced. For this reason, it is important in the dehydration process to measure the coagulation state of sludge and add an appropriate amount of coagulant to achieve the best coagulation state.

Conventionally, sludge stock solutions containing suspended solids such as sewage sludge, sewage sludge, industrial wastewater sludge, etc., reduce the moisture content of dehydrated sludge by adding flocculants to form suspended flocs. I am trying. In order to control the aggregated state of suspended solids in the sludge stock solution, the aggregated state of suspended solids in the coagulation mixing tank, that is, the flocs that aggregate the suspended solids are photographed, and the captured image is binarized. There is a method of controlling the addition rate of the flocculant by analyzing the agglomeration state of the suspended substance based on the floc ratio obtained in this way (see, for example, Patent Document 1). Here, depending on the type of sludge, the sludge undiluted solution has different behavior regarding the relationship between the total area of the coagulating flocs and the cake moisture of the dewatered cake dehydrated by the dehydrator with respect to the increase / decrease of the addition rate of the flocculant added to the sludge undiluted solution. With the conventional control method of the flocculant addition rate, it is possible to control the flocculant addition rate with respect to the sludge stock solution exhibiting the characteristics shown in FIG. That is, as a premise of control over the flocculant addition rate, the size of the flocculent floc is proportional to the amount of flocculant added, and the larger the flocculant floc, the larger the gap in the captured image. Therefore, the total area of aggregation flocs in one image is inversely proportional to the amount of aggregation agent added. This tendency becomes prominent particularly when binarization is performed based on the luminance signal of the captured image. Further, the cake moisture is not generally proportional to the flocculant addition rate, and when the flocculant floc is generated at the optimum flocculant addition rate, the cake moisture after dehydration also decreases. Therefore, when an example of the control of the conventional flocculant addition rate is shown, the cake moisture decreases most when the flocculant addition rate is around 0.6% as shown in FIG. when 6% as a reference of flocculant addition rate, a) der area of flocs was measured during operation 55000 or lever, when the current flocculant addition rate to the left than the reference flocculant addition rate It can be considered that by increasing the flocculant addition rate, it can be controlled to approach the reference flocculant addition rate which is the optimum flocculant addition rate. In addition, if the floc area measured during operation is 55000 or less , the current flocculant addition rate is considered to be on the right of the standard flocculant addition rate, and by reducing the flocculant addition rate, It can be controlled to approach the standard flocculant addition rate, which is the optimum flocculant addition rate.

  However, depending on the type of sludge stock solution, there are some which have the behavior shown in FIG. 9 regarding the relationship between the total area of the aggregated flocs and the cake moisture of the dehydrated cake dehydrated by the dehydrator. That is, the total area of coagulation flocs in one image is a sludge stock solution that is not inversely proportional to the amount of coagulant added.

  For such a sludge stock solution, it is impossible to control the flocculant addition rate even if a conventional method for controlling the flocculant addition rate is used. That is, as shown in FIG. 9, since the moisture content of the cake is the lowest when the flocculant addition rate is around 0.6%, the floc of the floc measured during the operation is determined using the flocculant addition rate at this time as the standard flocculant addition rate. When the area is 56000, there is a problem that the flocculant addition rate cannot be controlled because it cannot be determined whether to increase or decrease the flocculant addition rate in order to approach the reference flocculant addition rate.

Japanese Patent No. 4238898

In view of the above problems, the present invention, the aggregation state of the flocs in the sludge concentrate measured with high accuracy, sludge treatment side to prevent control and abnormal operation the amount and stirring intensity condensation mixing tank flocculant The purpose is to provide the law.

In order to achieve the above object, the present invention comprises a flocculent mixing tank for storing a sludge raw liquid supplied by a sludge raw liquid supply pump and a flocculant supplied by a flocculant supply pump, and stirring the sludge raw liquid and the flocculant in the coagulation mixing tank. The present invention relates to a sludge treatment method for controlling a sludge treatment apparatus having a coagulant stirrer that performs a dewatering process in which a sludge stock solution containing a coagulation floc that is a suspended substance formed in a coagulation mixing tank is supplied through a sludge stock solution supply pipe. That is, in the sludge treatment method of the present invention, (a) the imaging unit images the aggregated floc passing through the sludge stock solution supply pipe, and (b) the conversion unit captures the aggregated floc image captured by the imaging unit. A gradation binary image is generated based on the gradation information that the image capturing unit has, and a luminance binary image is generated based on the information on the luminance of the image from the aggregated flock image captured by the imaging unit. Is set in advance in the vicinity of the initial flocculant addition rate in the luminance aggregation floc average area, which is an average value of a plurality of luminance aggregation floc measurement areas calculated for the same flocculant addition rate. was calculated luminance flocs average area for each different flocculant addition indices in the ratio, the minimum value among the plurality of luminance floc average area and luminance flocs reference area, luminance aggregation floppy The flocculant rate at the reference time area calculating a reference coagulant addition ratio to calculate the gradation floc reference area based on the reference flocculant ratio conversion unit at any flocculant ratio is generated gradation calculates a gradation floc measuring area on the basis of the binary image, out calculate the error rate is the percentage of the difference between the gradation floc measuring area against the gradation flocs reference area, the comparator unit (d) The gradation aggregation floc measurement area and the gradation aggregation floc reference area are compared, and the rotation speed of the flocculant stirrer is compared with the predetermined maximum rotation speed and minimum rotation speed. and Saritsu erroneous that by the calculating unit, in accordance with the comparison result by the comparison unit, to control the rotational speed of at least coagulant supply pump to the gradation floc measuring area gradation flocs reference area, the ( ) The output part is agglomerating agent Rotational speed of the machine is characterized in that issue a warning if it becomes less than the maximum or speed or minimum number of revolutions predetermined.

According to the present invention, the aggregation state of the flocs in the sludge concentrate was measured to high accuracy, to provide a sludge treatment how to prevent control and abnormal operation the amount and stirring intensity condensation mixing tank flocculant be able to.

1 is a block diagram of a sludge treatment apparatus according to a first embodiment of the present invention. It is the schematic of the sludge processing apparatus which concerns on the 1st-3rd embodiment of this invention. It is the schematic of the sludge processing apparatus which concerns on the 1st-3rd embodiment of this invention. It is a calculation flowchart figure of the reference | standard flocculant addition rate by the brightness | luminance reference | standard binarization conversion which concerns on the 1st-3rd embodiment of this invention. It is a calculation flowchart figure of the gradation aggregation flock reference area by the gradation reference binarization conversion according to the first to third embodiments of the present invention. It is a flowchart figure of the sludge processing method which concerns on the 1st-3rd embodiment of this invention. It is a flowchart figure of the sludge processing method which concerns on the 1st-3rd embodiment of this invention. It is a graph which shows the characteristic of the conventional sludge stock solution which concerns on the 1st-3rd embodiment of this invention. It is a graph which shows the characteristic by the brightness | luminance reference | standard of the sludge stock solution which concerns on the 1st-3rd embodiment of this invention. It is a graph which shows the characteristic by the gradation reference | standard of the sludge stock solution which concerns on the 1st-3rd embodiment of this invention. It is a graph which shows the characteristic by the gradation reference | standard of the sludge stock solution which concerns on the 1st-3rd embodiment of this invention. It is a graph which shows the characteristic by the gradation reference | standard of the sludge stock solution which concerns on the 1st-3rd embodiment of this invention. It is a flowchart figure of the sludge processing method which concerns on the modification of the 1st Embodiment of this invention. It is a graph of the sludge treatment method which concerns on the 2nd Embodiment of this invention. It is a graph of the sludge treatment method which concerns on the 2nd Embodiment of this invention. It is a flowchart figure of the sludge processing method which concerns on the 2nd Embodiment of this invention. It is a block diagram of the sludge processing method which concerns on the 3rd Embodiment of this invention. It is a flowchart figure of the sludge processing method which concerns on the 3rd Embodiment of this invention. It is a block diagram of the sludge treatment method which concerns on the 4th Embodiment of this invention. It is a flowchart figure of the sludge processing method which concerns on the 4th Embodiment of this invention.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and the configuration of the apparatus and system is different from the actual one. Therefore, a specific configuration should be determined in consideration of the following description. In addition, it is a matter of course that portions having different configurations are included between the drawings.

  The following embodiments of the present invention exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is the material and shape of the component parts. The structure, arrangement, etc. are not specified as follows. The technical idea of the present invention can be variously modified within the technical scope described in the claims.

(First embodiment)
<Functional configuration of sludge treatment equipment>
As shown in FIGS. 1 and 2 , the sludge treatment apparatus according to the first embodiment of the present invention captures an image pickup unit 11 that picks up the flocs passing through the sludge stock solution supply pipe 33 and the image pickup unit 11 picks up the image. A conversion unit 12 that binarizes an image of the aggregation floc and generates a binary image, an aggregation floc measurement area that is an area of the aggregation floc displayed in the binary image generated by the conversion unit 12, and a preset initial aggregation A calculation unit 13 that calculates the aggregated floc reference area based on the agent addition rate, and a comparison unit 14 that compares the aggregated floc measurement area that is the area of the aggregated floc calculated after the start of the operation of the dehydrator 35 with the aggregated floc reference area The controller 15 that controls the rotation speed of the flocculant supply pump 29 and the flocculant stirrer 21 according to the comparison result by the comparison unit 14 and the alarm according to the comparison result by the comparison unit 14. And a power unit 16.

  The sludge treatment apparatus 100 according to the first embodiment of the present invention controls a sludge stock solution having sludge properties as shown in FIG. As shown in FIG. 8, in the sludge properties related to the conventional sludge stock solution control, the aggregation floc measurement area decreases as the flocculant addition rate increases. However, in the sludge properties of the sludge stock solution shown in FIG. 9, the increase / decrease relationship is reversed centering on a flocculant addition rate of 0.6% and an aggregation floc measurement area of 55000 pixels. Here, the aggregated floc measurement area is the number of pixels of the aggregated floc image.

  The imaging unit 11 captures an image of the inside of the visual examination device 45 through the visual examination window 34 shown in FIG. 2 and outputs it as an image. The inspection apparatus 45 is disposed in the sludge stock solution supply pipe 33 connected to the dehydrator 35, and includes an inspection window 34 at an arbitrary position. The imaging unit 11 can employ the TV camera 31 and the CCD camera shown in FIG.

  The conversion unit 12 binarizes the aggregated flock image captured by the imaging unit 11 and generates a binary image. The conversion unit 12 includes a gradation conversion unit 18 and a luminance conversion unit 19. The gradation converting unit 18 binarizes the aggregated floc image based on the gradation information included in the image. Further, the luminance conversion unit 19 binarizes the aggregated floc image based on the luminance information included in the image. The binary image converted by the gradation conversion unit 18 is referred to as “gradation binary image”, and the binary image converted by the luminance conversion unit 19 is referred to as “brightness binary image”.

  The calculation unit 13 calculates an “aggregated floc measurement area” from the data binarized by the conversion unit 12. Here, the “flocculation floc measurement area” is an area of the aggregation floc displayed on the image calculated by the calculation unit 13 based on the binary image of the aggregation floc converted by the conversion unit 12. In particular, the area of the entire aggregated floc displayed in the image is referred to as “total aggregated floc area”. The area per unit aggregated floc, obtained by dividing the “total aggregated floc area” by the number of aggregated flocs displayed in the image calculated by the calculation unit 13, is referred to as “aggregated floc single area”. As the “flocculation floc measurement area”, either “aggregation floc total area” or “aggregation floc single area” can be applied.

  Further, the calculation unit 13 calculates the aggregated floc measurement area for a plurality of times at the same flocculant addition rate in advance, calculates an “aggregated floc average area” that is an average value of the aggregated floc measurement areas for the plurality of times, Based on the “average area”, the “aggregated floc reference area” is calculated. Here, the area of the aggregated floc displayed in the “luminance binary image” captured after the start of the operation of the dehydrator 35 is the “luminance aggregated floc measurement area” and the area of the aggregated floc displayed in the “gradation binary image”. Is the “gradation aggregation floc measurement area”. For the same flocculant addition rate, the average value of luminance aggregation floc measurement area for the preset number of times is “luminance aggregation floc measurement area”, and the average value of gradation aggregation floc measurement area is “gradation”. It is referred to as “aggregated floc average area”.

  The calculation unit 13 calculates a luminance aggregation floc average area for each of a plurality of coagulant addition rates different from each other at a “preset ratio” in “near the initial coagulant addition rate”, and calculates the plurality of calculated luminances The area having the smallest value in the average aggregated floc area is defined as “luminance aggregated floc reference area”. “Near the initial flocculant addition rate” refers to a degree within the range of ± 0.3% of the initial flocculant addition rate RP [0]. The “predetermined ratio” is a difference between adjacent flocculant addition ratios and refers to about 0.01% to 0.1%. For example, in all seven stages including “initial flocculant addition rate” and increased / decreased by 0.02%, 0.04% and 0.06% before and after “initial flocculant addition ratio”, the flocculant flocs in each stage The calculating unit 13 calculates the average area. The number of samples when averaging at each stage of the flocculant addition rate is appropriately determined according to the type of sludge stock solution, user experience, and calculation speed. The image of the aggregation floc as a sample is captured at intervals of 10 to 60 seconds at each stage of the aggregation agent addition rate. Based on the captured image, the calculation unit 13 calculates the area of each aggregated floc as a sample. Based on the calculation result, seven aggregated floc average areas are obtained. The obtained average aggregated floc area is defined as “aggregated floc reference area”.

  Further, when the calculation unit 13 preliminarily calculates the value of the first flocculant addition rate in the vicinity of the reference flocculant addition rate, the calculation unit 13 calculates the first value in the vicinity of the reference flocculant addition rate. The average floc floc area with respect to the flocculant addition rate of the flocculant and the flocculent floc average area at the second flocculant addition rate different from the first flocculant addition rate set in advance are compared. Determine the rate of flocculant addition to the average floc area. Further, the calculation unit 13 calculates and compares the aggregated floc average area with respect to a plurality of the flocculant addition ratios in the vicinity of the flocculant addition ratio from the determined value of the flocculant addition ratio, and the aggregated goods having the minimum aggregated floc average area Determine the rate of addition. Such a process can be repeated until the aggregated floc average area converges as a minimum value, and the converged aggregated floc average area value can be used as the aggregated floc reference area.

  The “reference flocculant addition rate” is the flocculant addition rate when the “aggregation floc reference area” is calculated. The “reference flocculant addition rate” calculated by the sludge treatment apparatus 100 according to the first embodiment of the present invention corresponds to the “luminance aggregation floc reference area”. Further, the aggregation floc measurement area calculated from the “gradation binary image” captured at the “reference flocculant addition rate” is defined as “gradation aggregation floc reference area”. Furthermore, the “initial flocculant addition rate” is an arbitrary flocculant addition rate determined under a certain condition, and is obtained based on accumulated experience values obtained by operating the sludge treatment apparatus 100 in the past. decide.

  The comparison unit 14 compares the “aggregated floc measurement area” and the “aggregated floc reference area”. The comparison unit 14 according to the first exemplary embodiment of the present invention includes a “gradation aggregation floc measurement area” calculated by the calculation unit 13 based on a binary binary image, and an addition of a flocculant when calculating a luminance aggregation floc reference area. The “gradation aggregation floc reference area” calculated by the calculation unit 13 based on the gradation binary image at the reference aggregation agent addition rate, which is the rate, is compared.

Based on the comparison result between the “gradation aggregation floc measurement area” and the “gradation aggregation floc reference area” by the comparison unit 14, the control unit 15 determines the addition amount of the flocculant by the flocculant supply pump 29 shown in FIG. Control. Further, the control unit 15 controls the rotation speed of the coagulant stirrer 21 provided in the coagulation mixing tank 25 based on the comparison result by the comparison unit 14.

  Details will be described below with reference to FIGS. As shown in FIG. 9, with respect to the sludge stock solution processed by the sludge treatment apparatus 100 according to the embodiment of the present invention, the brightness conversion is performed based on the brightness information included in the image as the addition rate of the flocculant added to the sludge stock solution increases. The luminance aggregation floc measurement area calculated by the calculation unit 13 is reduced from the luminance binary image converted by the unit 19, and the luminance aggregation floc measurement is performed with an increase in the flocculant addition rate equal to or greater than the threshold, with a specific flocculant addition rate as a threshold. The area increases. In addition, for the sludge stock solution processed by the sludge treatment apparatus 100 according to the embodiment of the present invention, the cake moisture of the dehydrated cake treated by the dehydrator 35 decreases with the increase in the addition rate of the flocculant added to the sludge stock solution, When the specific flocculant addition rate is exceeded, the cake moisture increases as the flocculant addition rate increases. The flocculant addition rate corresponding to when the luminance aggregation floc measurement area takes the minimum value and the flocculant addition rate corresponding to when the cake moisture takes the minimum value are almost the same value. That is, in order to treat the sludge undiluted solution in an optimum state where the cake moisture is minimized, the flocculant addition rate measured during the operation of the sludge treatment apparatus 100 needs to be the same as the reference flocculant addition rate. However, since the sludge properties change during the operation of the sludge treatment apparatus 100, the measured luminance aggregation floc measurement area changes even if the addition amount of the flocculant is constant. Therefore, in order to realize high-quality processing, it is necessary to control the luminance aggregation floc measurement area measured during operation to approach the minimum value. Note that the luminance aggregation floc measurement area calculated by the calculation unit 13 exhibits the same characteristics both in the total area of the entire aggregation floc and in the luminance aggregation floc single area that is an area per unit aggregation floc.

  Here, FIG. 10 shows the characteristics of the sludge stock solution similar to FIG. 9 indicated by the gradation aggregation floc measurement area calculated by the calculation unit 13 based on the gradation information included in the sludge stock solution image and the flocculant addition rate. . As shown in FIG. 10, as the flocculant addition rate increases, the gradation aggregation floc measurement area simply increases. Therefore, by comparing the gradation aggregation floc reference area corresponding to the reference flocculant addition ratio and the gradation aggregation floc measurement area, the basic flocculant addition ratio during operation can be easily and quickly determined. Control close to is possible. That is, in FIG. 10, when the gradation aggregation floc measurement area> the gradation aggregation floc reference area, the flocculant addition rate during operation can be made closer to the reference flocculant addition rate by reducing the flocculant addition rate. Become. Further, when the gradation aggregation floc measurement area is smaller than the gradation aggregation floc reference area, it is possible to bring the flocculant addition rate during operation closer to the reference flocculant addition rate by increasing the flocculant addition rate.

  However, as shown in FIG. 9, in the characteristics of the luminance-based sludge stock solution based on the luminance information, the flocculant corresponding to a specific luminance aggregation floc measurement area value, for example, a luminance aggregation floc measurement area value around 56000 Since there are two types of addition rate values, the flocculant addition rate during operation is increased in order to approach the reference flocculant addition rate only by comparing the size of the luminance aggregation floc measurement area and the luminance aggregation floc reference area. It is impossible to judge whether or not to decrease.

Therefore, the comparison unit 14 according to the first exemplary embodiment of the present invention compares the “gradation aggregation floc measurement area” with the “gradation aggregation floc reference area”. FIG. 10 is a graph showing the characteristics of the sludge stock solution with respect to the total area of the aggregated flocs. As shown in FIGS. 11 and 12, the area per unit aggregated floc is obtained by dividing the total aggregated floc area by the number of aggregated flocs. Since the same graph shape is shown even with a certain luminance aggregation floc single area, the control unit 15 according to the first embodiment of the present invention can perform the same control.

  That is, the sludge treatment apparatus 100 according to the first embodiment of the present invention calculates the gradation aggregation floc corresponding to the reference flocculant addition rate calculated based on the gradation information included in the image captured by the imaging unit 11. By comparing the reference area with the gradation aggregation floc measurement area measured during operation of the sludge treatment apparatus 100 and calculated based on the gradation information, it is possible to carry out optimum treatment of the sludge stock solution quickly and easily. It becomes.

Next, when processing the sludge stock solution having the characteristics shown in FIG. 9, the control unit 15 obtains the result of comparison by the comparison unit 14 as gradation aggregation flock measurement area> gradation aggregation floc reference area and calculation unit. When the “error rate” expressed by Equation (1) exceeds “predetermined specific value” (hereinafter referred to as “error default value”), the amount of flocculant added is decreased. Thus, the flocculant supply pump 29 is controlled so that the flocculant addition rate decreases. That is, at this time, the control unit 15 decreases the rotation speed of the coagulant supply pump 29 so that the coagulant addition rate is decreased by a “preset value”. Here, the “error rate” is the ratio of the difference of the gradation aggregation flock measurement area to the gradation aggregation flock reference area. When the error rate of the gradation aggregation floc measurement area with respect to the gradation aggregation floc reference area is ε, the gradation aggregation floc measurement area is gFAm, and the gradation aggregation floc reference area is gFA, the following equation is established.
ε = {(gFAm−gFA) / gFA} × 100 (1)

  When the error rate is equal to or less than the predetermined error value, the control unit 15 maintains the rotational speed of the coagulant supply pump 29 and continues to maintain the coagulant addition rate. Here, the “preset value” is an adjustment width when the gradation aggregation floc measurement area approaches the gradation aggregation floc reference area, and may be set to 0.05% based on the experience value so far. It can be set to 0.01%.

  Further, when the gradation aggregation floc measurement area is smaller than the gradation aggregation floc reference area and the error rate is larger than the error default value, the control unit 15 increases the rotation speed of the aggregation agent supply pump 29, The flocculant addition rate is controlled to increase by a preset value. When the gradation aggregation floc measurement area is larger than the gradation aggregation floc reference area and the error rate is larger than the error default value, the control unit 15 reduces the number of rotations of the aggregation agent supply pump 29 to thereby increase the aggregation agent. Control is performed so that the addition rate decreases by a preset value.

  Here, the “default error value” is a value related to a difference between the aggregated floc measurement area and the aggregated floc reference area. Further, it is a value that is negligible as an error caused by accuracy in an actual device or the like, and is a minute value that does not actually affect the determination of the reference aggregation addition rate.

  Subsequently, after the control unit 15 performs control to reduce the coagulant addition rate, when the coagulant addition rate after the decrease is equal to or less than the preset minimum coagulant addition rate, the output unit 16 described in detail later gives an alarm. Is output. Further, when the reduced flocculant addition rate is greater than the minimum flocculant addition rate, the control unit 15 controls the flocculant addition rate to be further reduced by reducing the rotational speed of the flocculant supply pump 29. After the control unit 15 performs control to increase the flocculant addition rate, when the increased flocculant addition rate is equal to or higher than the preset maximum flocculant addition rate, the control unit 15 rotates the rotation speed of the flocculant stirrer 21. By reducing the flocculant addition rate, the control unit 15 controls the rotational speed of the flocculant supply pump 29 when the increased flocculant addition rate is smaller than the maximum flocculant addition rate. It is controlled so as to further increase the flocculant addition rate after the increase.

  When the error rate is equal to or less than the predetermined error value, the control unit 15 maintains the rotation speed of the coagulant stirrer 21, the gradation aggregation floc measurement area is smaller than the gradation aggregation floc reference area, and the error rate is When the error is larger than the predetermined value, the control unit 15 can reduce the rotation speed of the flocculant stirrer 21 to bring the flocculant addition rate during operation closer to the reference flocculant addition rate. When the gradation aggregation floc measurement area is larger than the gradation aggregation floc reference area and the error rate is larger than the error default value, the control unit 15 increases the number of rotations of the aggregating agent agitator 21 during operation. It is also possible to bring the flocculant addition rate close to the reference flocculant addition rate.

  When an abnormality occurs in the sludge treatment apparatus 100 under certain conditions, the output unit 16 provides information on the abnormal state to the user of the sludge treatment apparatus 100. Here, the “certain condition” may be a case where the difference between the aggregate floc reference area and the aggregate floc measurement area reaches an abnormal value, or the error rate of the aggregate floc measurement area with respect to the aggregate floc reference area It is also possible that the difference between the error and the error default value reaches an abnormal value. Here, the “abnormal value” refers to various values when a user who is skilled in handling can clearly determine that an abnormal state has occurred in the original specifications of the sludge treatment apparatus 100 during the treatment of the sludge treatment apparatus 100. Points to the value.

  The output method and output format are suitable for calling the user of the sludge treatment apparatus 100 to call attention. For example, it is possible to output a video signal and display an image and a character on the display unit, and it is also possible to output a sound signal and output a sound.

  The storage device 17 stores the aggregated floc measurement area calculated by the calculation unit 13, the aggregated floc reference area, the reference flocculant addition rate, the error rate and the error default value, the comparison result compared by the comparison unit 14, and the like. To the control unit 15 and the like.

  The storage device 17 shown in FIG. 1 of the sludge treatment apparatus 100 according to the embodiment of the present invention supports management of the imaging unit 11, the conversion unit 12, the calculation unit 13, the comparison unit 14, the control unit 15, and the output unit 16. Is stored, and the addition amount of the coagulant input by a user interface means (not shown) based on the user's instruction, the stirring intensity of the coagulant stirrer 21 in the coagulant mixing tank 25, and the like are stored. Further, an image of the aggregated flock captured and output by the imaging unit 11 and data obtained by binarizing the image by the conversion unit 12 are also stored. Furthermore, a program related to management of data calculation processing by the imaging unit 11, the conversion unit 12, the calculation unit 13, the comparison unit 14, the control unit 15, the output unit 16, and the like is read and executed by a central processing unit (not shown) of the sludge processing apparatus 100. By doing so, the imaging unit 11, the conversion unit 12, the calculation unit 13, the comparison unit 14, the control unit 15, the output unit 16, and the like are mounted on the sludge treatment apparatus 100.

<Equipment configuration of sludge treatment equipment>
As shown in FIGS. 2 and 3, the apparatus configuration of the sludge treatment apparatus 100 according to the embodiment of the present invention stores a sludge stock solution containing suspended solids and a sludge storage tank 22 in which a stirrer 26 is disposed. And a sludge stock solution supply pump 23 for press-fitting a certain amount of sludge stock solution into the bottom of the coagulation mixing tank 25 from the press-fitting pipe 24, and a polymer dissolution tank 27 in which a stirrer 26 is provided and the flocculant is stored. A flocculant supply pump 29 for adding a variable capacity flocculant in the range of 0.3 to 1.0% from the polymer dissolution tank 27 to the sludge stock solution in the press-fitting pipe 24, and a sludge stock solution supplied by the sludge stock solution supply pump 23 The flocculant mixing tank 25 for storing the flocculant supplied by the flocculant supply pump 29, and the flocculant stirrer 21 connected to the stirrer motor 30 for stirring the sludge stock solution and the flocculant in the flocculent mixing tank 25; Agglomerated flocs which are suspended substances formed in the tank 25 Sludge stock containing comprises a dehydrator 35 is fed through the sludge solution feed pipe 33. The flocculant stirrer 21 disposed in the flocculation mixing tank 25 can stir the sludge stock solution and the flocculant at a speed of usually 40 rpm, and can increase and decrease the speed in steps of 3 to 5 rpm.

  In addition, the sludge treatment apparatus 100 according to the embodiment of the present invention is configured so that the sludge stock solution to which the flocculant of the flocculent mixing tank 25 is added is stirred by the flocculant stirrer 21 so that the suspended solids contained in the sludge stock solution are mixed. Aggregated flocs are formed, and the dehydrator 35 separates and discharges the aggregated flocs formed from the sludge stock solution supplied from the sludge stock solution supply pipe 33. In addition, the sludge treatment apparatus 100 includes a sludge stock solution supply pipe 33 that supplies a sludge stock solution containing aggregated flocs to the dehydrator 35 at a tank pressure, and a visual inspection device 45.

Further, as shown in FIG. 3 , an imaging television camera 31 that captures an image of the inside of the visual examination device 45 through the visual examination window 34 of the visual examination device 45 and outputs it as an image, and binarizes the image to calculate an aggregation floc measurement area and the like. The calculation device 44, the aggregated floc measurement area and the aggregated floc reference area are compared, a control signal is output according to the comparison result, and the coagulant supply pump 29, the coagulant stirrer 21 and And a sequencer proportional control device 42 for controlling the abnormality signal device 43.

Connected to the coagulation mixing tank 25 is a sludge stock solution supply pipe 33 that supplies the formed sludge stock solution containing the aggregated floc to the screw press 32 of the dehydrator 35. In the embodiment of the present invention, the screw press 32 is used as the dehydrator 35, but a known dehydrator such as a centrifugal dehydrator or a belt-type dehydrator can also be used. The sludge stock solution is pressed into the screw press 32 at the tank pressure of the coagulation mixing tank 25 by using the press-fitting pressure into the coagulation mixing tank 25 by the sludge raw material supply pump 23, and the aggregated flocs that are the aggregated suspended material are broken by pulsation. I am trying not to. The sludge stock solution supply pipe 33 is provided with a viewing window 34 that enables imaging of the state of the aggregated floc. The viewing window 34 can be circular or polygonal. The television camera 31 is disposed at a position 10 to 40 cm away from the inspection window 34 disposed in the sludge stock solution supply pipe 33. The television camera 31 corresponding to the imaging unit 11 shown in FIG. 1 captures the aggregated floc passing through the sludge stock solution supply pipe 33 once every 15 to 30 seconds, and converts the luminance signal into a digital signal. Luminance information of the electrical signal is transmitted to the controller 37, the controller 37 transmits an image of flocs to the arithmetic unit 44. The image luminance information of the aggregated floc group transmitted from the television camera 31 is stored in the image board 38 of the arithmetic unit 44 shown in FIG. This image information is binarized in accordance with more luminance level to the binarization circuit 39.

The binarized aggregated floc group image information is input to the arithmetic circuit 40 to calculate the aggregated floc measurement area, the aggregated floc reference area, and the like. Area information for flocs that have been transmitted from the arithmetic unit 44 to the signal converter 41 converts the digital signal into an analog signal, is sent to the sequencer proportional control device 42. The sequencer proportional control device 42 compares various areas of the flocculation flocs based on the comparison information of the flocculant addition rate with respect to the fluctuation of the suspended solid amount in the sludge stock solution and the fluctuation of the concentration inputted in advance. The number of rotations of the flocculant stirrer 21, the flocculant supply pump 29, and the abnormal signal device 43 are controlled.

  When the aggregation floc measurement area is excessive, the sequencer proportional control device 42 reduces the aggregation floc measurement area by reducing the addition rate of the flocculant or increasing the rotation speed of the flocculant stirrer 21. Move closer to the reference area. Further, when the aggregation floc measurement area is very small, the sequencer proportional controller 42 increases the aggregation floc measurement area by increasing the addition rate of the flocculant or decreasing the rotation speed of the flocculant stirrer 21. Close to the aggregate floc reference area.

<Calculation method of reference flocculant addition rate by luminance reference binarization conversion>
Next, the sludge treatment apparatus according to the first embodiment of the present invention, the method for determining the reference flocculant addition rate by calculating the aggregation floc measurement area based on the luminance information included in the image of the aggregation floc, This will be described with reference to the flowchart of FIG.

  Here, “initial flocculant addition rate” is RP [0], “initial luminance flocculant floc area” is bFA [0], “flocculating agent addition rate difference” is α, and “nth flocculant addition rate” is RP [ n], “nth luminance aggregation floc area” is bFA [n], “reference flocculant addition rate” is RP, “luminance aggregation floc reference area” is bFA, and “nth luminance aggregation floc average area” is ave (bFA). [N]), “the number of sampling times when calculating the average area” is a. The “nth luminance aggregation floc average area” is the average value of the luminance aggregation floc measurement area for the number of samplings at the nth flocculant addition rate, and the following equation holds.

ｂＦＡ＝ｍｉｎ｛ａｖｅ（ｂＦＡ［ｎ］）｝、ｎ＝０〜ｎ ・・・（４）
また、式（４）は、初期輝度凝集フロック平均面積の値ａｖｅ（ｂＦＡ［０］）、第１輝度凝集フロック平均面積の値ａｖｅ（ｂＦＡ［１］）、・・・、第ｎ輝度凝集フロック平均面積の値ａｖｅ（ｂＦＡ［ｎ］）の中の最小値が「凝集フロック基準面積」であることを示す。 α = RP [n + 1] −RP [n], α = 0.01 to 0.1 (2)

bFA = min {ave (bFA [n])}, n = 0 to n (4)
In addition, the equation (4) is obtained by using an initial luminance aggregation floc average area value ave (bFA [0]), a first luminance aggregation floc average area value ave (bFA [1]),. The minimum value among the average area values ave (bFA [n]) is the “aggregated floc reference area”.

  (A) In step S101 shown in FIG. 4A, the luminance conversion unit 19 uses the luminance information included in the image of the aggregated floc images at the aggregation agent addition rates RP [0] to RP [n] captured by the imaging unit 11. Are converted into a binary luminance image (based on the luminance reference), and the calculation unit 13 calculates luminance aggregation flock measurement areas bFA [0] to bFA [n] from the converted luminance binary image. At this time, the calculation unit 13 calculates the luminance aggregation floc measurement area bFA [n] a times at the same aggregation agent addition rate RP [n]. Here, “a” is an arbitrary value set in advance, and an optimum value is empirically set depending on the calculation load and calculation speed of the sludge treatment apparatus 100, the accuracy of the calculation result, and the like. The calculation unit 13 repeats the calculation of a times of the luminance aggregation floc measurement area bFA [n] for each of n = 0 to n. “N” is a variable from 1 to an arbitrary value set in advance, and from step S101 to step S105, the process is repeated with an increment of 1 from 1 to n. Similarly to “a”, the optimum value of “n” is set empirically depending on the calculation load and the calculation speed of the sludge treatment apparatus 100, the accuracy of the calculation result, and the like.

  (B) In step S102, the calculation unit 13 calculates the average value ave (bFA [0]) to ave (bFA [n) of the aggregating floc measurement areas for the flocculant addition rates RP [0] to RP [n]. ]) Respectively. In step S103, the calculation unit 13 determines the minimum value from the average values ave (bFA [0]) to ave (bFA [n]) calculated in n = 0 to n, and in step S104, the calculation unit 13 The determined minimum value is defined as the aggregated floc reference area bFA. In step S105, the calculation unit 13 recognizes the flocculant addition rate at the time of calculating the flocs floc reference area corresponding to bFA as the reference flocculant addition rate.

  Next, FIG. 4B is a flowchart showing an algorithm in the calculation method of the reference flocculant addition rate by the luminance reference binarization conversion corresponding to FIG. 4A.

  Routines R11-1 to 11-2 are a subroutine of an iterative process for calculating the luminance aggregation floc measurement area by repeating a times at the same flocculant addition rate RP [n]. Routines R12-1 to 12-2 are repetitive processing subroutines that repeatedly calculate the luminance aggregation floc average area for each of different aggregation agent addition rates RP [0],..., RP [n].

  In step S11, the imaging unit 11 images the sludge stock solution. In step S <b> 12, the luminance conversion unit 19 converts the image captured by the imaging unit 11 into a luminance binary image based on the luminance. In step 13, the calculation unit 13 calculates a luminance aggregation floc measurement area bFA [n] from the luminance binary image. In the routines R11-1 to 11-2, the calculation unit 13 calculates bFA [n] a times. In step S14, the calculation unit 13 calculates the luminance aggregation flock average area ave (bFA [n]), which is an average value of bFA [n] at a times.

In the routines R12-1 to 12-2, the calculation unit 13 calculates the luminance aggregation flock average area ave (bFA [n]) at n = 0 to n, respectively. In step S15, the calculation unit 13 determines the minimum value from the luminance aggregation flock average areas ave (bFA [0]) to ave (bFA [n]), and sets the minimum value min {bFA [n]} to the luminance aggregation. Set to the flock reference area bFA. In step S16, the calculation unit 13 recognizes the aggregation addition rate when bFA is calculated as the reference aggregation agent addition rate.
<Calculation method of gradation aggregation flock reference area by gradation reference binarization conversion>
Next, a method in which the sludge treatment apparatus according to the embodiment of the present invention controls the size of the aggregate floc will be described with reference to the flowchart of FIG.

  Here, “grayscale aggregation floc reference area” is gFA, “i-th gradation aggregation floc measurement area” is gFA [i], “i-th gradation aggregation floc average area” is ave (gFA [i]), “ The number of sampling times when calculating the average area is b. The “i-th gradation aggregation floc average area” is an average value of gradation aggregation floc measurement areas for the number of samplings at the i-th aggregation agent addition rate, and the following equation holds.

ｇＦＡ＝ａｖｅ（ｇＦＡ［ｉ］）｝、ｉ＝０〜ｎ ・・・（６）

gFA = ave (gFA [i])}, i = 0 to n (6)

  In the following description of the processing, the area of the aggregated floc is described as the total area that is the area of the entire aggregated floc, but is the area per unit aggregated floc obtained by dividing the total area of the aggregated floc by the number of aggregated flocs. It is possible to carry out the processing using a single area.

  (A) In step S201 shown in FIG. 5A, the gradation conversion unit 18 converts the aggregate floc image at the reference coagulant addition rate RP captured by the imaging unit 11 based on the gradation information included in the image (floor). A tone gradation flock measurement area gFA [i] is calculated from the converted tone binary image. At this time, the calculation unit 13 calculates the gradation aggregation floc measurement area gFA [i] b times at the reference aggregation agent addition rate RP. Here, “b” is an arbitrary value set in advance, and an optimum value is empirically set according to the ability of the sludge treatment apparatus 100 regarding the calculation load and calculation speed, the accuracy of the calculation result, and the like. “I” is an arbitrary value from 1 to n, and is a value determined when the reference flocculant addition rate is reached as shown in step S16 of FIG. 4B.

  (B) In step S202, the calculation unit 13 calculates an average value ave (gFA [i]) of b times of the gradation aggregation floc measurement area at the reference aggregation agent addition rate RP. In step S203, the calculation unit 13 determines the gradation aggregation flock average area ave (gFA [i]) as the gradation aggregation flock reference area gFA.

  Next, FIG. 5B is a flowchart corresponding to FIG. 5A, showing an algorithm in a method for calculating a gradation aggregation flock reference area by gradation reference binarization conversion.

  Routines R21-1 to 21-2 are subroutines of an iterative process for calculating the gradation aggregation floc measurement area by repeating b times at the reference aggregation agent addition rate RP.

(A) In step S21, the imaging unit 11 images the sludge stock solution. In step S22 , the gradation converting unit 18 converts the image captured by the image capturing unit 11 into a gradation binary image based on the gradation. In step 23, the calculation unit 13 calculates the gradation aggregation flock measurement area gFA [i] from the gradation binary image. In routine R21-1 to 21-2, the calculation unit 13 calculates gFA [i] b times. In step S24, the calculation unit 13 calculates a gradation aggregation flock average area ave (gFA [i]), which is an average value of gFA [i] at b times.

(B) In step S25, the gradation aggregation flock average area ave (gFA [i]) is determined as the gradation aggregation flock reference area .
<Aggregating floc control method by sludge treatment equipment>
Next, a method in which the sludge treatment apparatus 100 according to the first embodiment of the present invention controls the size of the aggregated floc will be described with reference to the flowcharts of FIGS. 6 and 7.

  (A) In step S301, based on a user instruction, the storage device 17 shown in FIG. 1 stores an initial setting value input by an interface unit (not shown). The initial set values used when the sludge treatment apparatus 100 according to the embodiment of the present invention controls the size of the flocculation floc are the initial sludge stock solution flow rate Qs [0], the initial sludge stock solution concentration D [0], and the initial flocculation. The agent addition rate RP [0], the maximum coagulant addition rate RPmax, the minimum coagulant addition rate RPmin, the initial stirring rotational speed AR [0], the maximum stirring rotational speed ARmax, the minimum stirring rotational speed ARmin, and the like. Here, if the sludge treatment apparatus 100 is operating normally, the stirring rotational speed AR of the flocculant stirrer 21 changes within the range of the allowable stirring rotational speed where the lower limit is ARmin and the upper limit is ARmax. Therefore, when it is outside the range of the allowable stirring rotation speed, that is, when AR <ARmin and AR> ARmax, the sludge treatment apparatus 100 can determine that some abnormality has occurred.

  (B) In step S302, the dehydrator 35 starts operation for sludge treatment. In step S303, the imaging unit 11 shown in FIG. 1 (the television camera 31 shown in FIG. 2) takes an image of the aggregated floc contained in the sludge stock solution passing through the sludge stock solution supply pipe 33 through the inspection window 34, and the conversion unit 12 has it. The luminance conversion unit 19 binarizes and converts the captured image into a luminance binary image, and the calculation unit 13 calculates the luminance aggregation flock reference area bFA based on the luminance binary image. In step S304, the calculation unit 13 calculates a reference flocculant addition rate RP based on the luminance aggregation floc reference area bFA. In step S305, the calculation unit 13 calculates the gradation aggregation flock reference area gFA based on the reference aggregation agent addition rate RP. In step S306, the calculation unit 13 calculates the gradation aggregation flock measurement area gFA [n] at an arbitrary aggregation agent addition rate RP [n].

  (C) In step S307, the comparison unit 14 compares the error rate of the gradation aggregation flock measurement area with respect to the gradation aggregation flock reference area and the error specified value β. Here, the gradation aggregation flock measurement area gFA [n] calculated by the calculation unit 13 in step S306 is applied, and the error rate of FA [n] is expressed as (gFA [n] −gFA) × 100 / gFA. . When the error rate of gFA [n] with respect to gFA is β or less, in step S308, the control unit 15 controls the flocculant supply pump 29 shown in FIG. Continue driving. If the error rate of gFA [n] is larger than β, in step S309, the comparison unit 14 determines the gradation aggregation floc measurement area gFA [n] and the gradation aggregation floc reference area gFA at the aggregation agent addition rate RP [n]. And compare. When gFA [n] is equal to or less than gFA, in step S310, the control unit 15 instructs the flocculant supply pump 29 shown in FIG. 2 so that the flocculant addition rate increases to RP [n + 1].

  (D) Subsequently, in step S311 shown in FIG. 7, the comparison unit 14 determines the flocculant addition rate RP [n + 1] after instructing the increase in step S310 and the maximum aggregation stored in the storage device 17 shown in FIG. The agent addition rate RPmax is compared. When RP [n + 1] is smaller than RPmax, in step S312, the control unit 15 controls the flocculant supply pump 29 shown in FIG. 2 so that the flocculant addition rate increases from RP [n] to RP [n + 1]. In step S313, the calculation unit 13 calculates the gradation aggregation flock measurement area gFA [n + 1] at the flocculant addition rate RP [n + 1], and the process proceeds to step S307 shown in FIG. The error rate of gFA [n + 1] with respect to β is compared with β. If RP [n + 1] is greater than or equal to RPmax in step S311, the control unit 15 instructs the coagulant stirrer 21 to decrease the rotational speed in step S314.

  (E) Subsequently, in step S315, the comparison unit 14 compares the stirring rotational speed AR, which is the rotational speed of the flocculant stirrer 21, with the maximum stirring rotational speed ARmax and the minimum stirring rotational speed ARmin. If it is below or above ARmax, that is, when the stirring rotation speed AR is outside the range of the allowable stirring rotation speed, in step S316, the output unit 16 determines that the stirring rotation speed AR at step S315 is an abnormal value. An alarm is output, and the process proceeds to step S303 shown in FIG. The alarm may be voice or video, or a combination thereof.

  (F) If the stirring rotational speed AR is larger than ARmin and smaller than ARmax in step S315, that is, if the stirring rotational speed AR is within the range of the allowable stirring rotational speed, in step S317, the control unit 15 performs aggregation. The agitator motor 30 shown in FIG. 2 is controlled so as to change the agitator rotation speed AR to an arbitrary rotation speed set in advance so that the agent addition rate RP [n] becomes RP [n + 1]. Subsequently, in step S318, the calculation unit 13 calculates the gradation aggregation floc measurement area gFA [n + 1] at the aggregation agent addition rate RP [n + 1]. In step S319, the comparison unit 14 compares the error rate of the gradation aggregation flock measurement area gFA [n + 1] calculated by the calculation unit 13 with respect to the gradation aggregation flock reference area gFA and the error default value β.

  (G) If the error rate of gFA [n + 1] with respect to gFA is smaller than −β in step S319, in step S320, the gradation aggregation flock measurement areas gFA [n + 1] and RP [ The gradation aggregation flock measurement area gFA [n + 2] in n + 2] is compared. If gFA [n + 1] is smaller than gFA [n + 2] in step S320, the process proceeds to step S314. If gFA [n + 1] is equal to or greater than gFA [n + 2], the process proceeds to step S303 shown in FIG. In step S319, when the error rate of gFA [n + 1] with respect to gFA is larger than β, in step S321, the controller 15 causes the stirrer motor 30 shown in FIG. 2 so that the rotational speed of the flocculant stirrer 21 increases. And the process proceeds to step S315.

  (H) In step S319, when the magnitude of the error rate of gFA [n + 1] with respect to gFA is β or less, in step S322, the control unit 15 causes the stirrer motor to maintain the rotational speed of the flocculant stirrer 21. 30 and the process proceeds to step S306 shown in FIG. Next, in step S309 shown in FIG. 6, when gFA [n] is larger than gFA, in step S323, the control unit 15 changes the flocculant addition rate to FIG. 2 so as to decrease to PR [n−1]. The indicated flocculant supply pump 29 is instructed. Subsequently, in step S324, the comparison unit 14 compares the reduced flocculant addition rate RP [n-1] in step S323 with the minimum flocculant addition rate RPmin stored in the storage device 17 illustrated in FIG. When RP [n−1] is equal to or less than RPmin, the output unit 16 illustrated in FIG. 1 outputs an alarm in step S325, and the process proceeds to step S303.

  (I) When RP [n−1] is larger than RPmin in step S324, the controller 15 causes the aggregation shown in FIG. 2 so that the flocculant addition rate decreases to RP [n−1] in step S326. The agent supply pump 29 is controlled. Subsequently, in step S327, the calculation unit 13 calculates the gradation flocculant addition rate gFA [n−1] at the flocculant addition rate RP [n−1], and then proceeds to step S307. The unit 14 compares β with an error rate of gFA [n−1] with respect to gFA.

  As described above, the sludge treatment apparatus according to the first embodiment of the present invention performs the optimum sludge treatment by controlling the flocculant addition rate so as to quickly and easily produce the optimum moisture sludge cake. It is possible. In order to carry out the optimum sludge treatment, it is necessary that the flocculant addition rate of the sludge stock solution maintains the reference flocculant addition rate so that the sludge cake maintains an optimal amount of water. In order to maintain the reference flocculant addition rate, the aggregation floc measurement area needs to maintain the aggregation floc reference area.

  That is, in the sludge, which is the property of the simple downward-sloping graph shown in FIG. 8, when controlling the reference flocculant addition rate, if the aggregate floc measurement area is 60000, it is close to the aggregate floc reference area 55000. In addition, the flocculant addition rate is controlled to decrease. By increasing the rotation speed of the flocculant supply pump 29 and increasing the supply amount of the flocculant, it is possible to control the flocculant addition rate in the sludge stock solution to be close to the reference flocculant addition rate.

  Further, if the aggregated floc measurement area is 52000, the flocculant addition rate is controlled to decrease to approach the aggregated floc reference area of 55000. By reducing the rotation speed of the coagulant supply pump 29 and reducing the supply amount of the coagulant, it is possible to control the coagulant addition rate in the sludge stock solution to be close to the reference coagulant addition rate. However, in the sludge having the properties shown in FIG. 9, when the floc floc measurement area is around 57000, there are a plurality of corresponding flocculant addition ratio values across the reference flocculant addition ratio. It is impossible to determine the increase or decrease.

  However, when the aggregated floc measurement area is calculated based on the gradation standard, the aggregated floc measurement area and the flocculant addition rate correspond one-on-one as shown in FIG. Shown in a simple relationship. Therefore, by examining the relationship between the aggregated floc measurement area calculated based on the gradation reference and the aggregated floc reference area, it is possible to quickly and easily maintain the reference flocculant addition rate.

  Next, FIG. 10 and FIG. 11 both show the relationship between the aggregation floc measurement area calculated based on the density reference and the flocculant addition rate. However, while FIG. 10 shows the relationship between the aggregated floc total area, which is the area of the entire aggregated floc displayed in the image, and the flocculant addition rate, FIG. 11 shows the number of aggregated flocs displayed in the image. The relationship between the coagulation floc single area which is the area per unit coagulation floc excluding the coagulation floc total area and the coagulant addition rate is shown. As shown in FIG. 11 and FIG. 12, the aggregated floc single area simply increases with an increase in the coagulant addition rate, similarly to the aggregated floc total area, so the aggregated floc single area is applied to the aggregated floc measurement area. However, it is possible to appropriately control the flocculant addition rate.

(Modification of the first embodiment)
As shown in FIG. 13, the sludge treatment apparatus according to the modification of the first embodiment of the present invention differs from FIG. 7 in steps S411, S414, S415, and S419. Further, steps S412 , S413 , S416 to S418 and S420 to S424 shown in FIG. 13 are the same as steps S312 to S316 and S318 to S322 shown in FIG. 7.

That is, in the sludge treatment apparatus 100 according to the modification of the first embodiment of the present invention, in step S411 shown in FIG.
(A) The comparison unit 14 compares the flocculant addition rate RP [n + 1] after instructing an increase in step S310 shown in FIG. 6 with the “aggregating agent addition rate stirring reference value RPar”. Here, the “aggregating agent addition rate stirring reference value RPar” is a value equal to or less than the maximum aggregating agent addition rate RPmax, and a threshold value when the control unit 15 shown in FIG. 1 rotates the agglomeration stirrer 21 shown in FIG. It is. Similar to the maximum coagulant addition rate RPmax, this value is preset when the sludge treatment apparatus 100 is operated, and is stored in the storage device 17 shown in FIG. The “flocculating agent addition rate stirring reference value RPar” is set in consideration of an empirical value in the conventional treatment, and a value of about 70 to 100% of the maximum flocculant addition rate RPmax is appropriate. It can be changed flexibly as appropriate depending on the performance of the apparatus 100 and the like.

  (B) If RP [n + 1] is smaller than RPar in step S411, the controller 15 shows in FIG. 2 that the flocculant addition rate increases from RP [n] to RP [n + 1] in step S412. The flocculant supply pump 29 is controlled, and in step S413, the calculation unit 13 calculates the gradation aggregation floc measurement area gFA [n + 1] at the flocculant addition rate RP [n + 1], and the process proceeds to step S307 shown in FIG. The comparing unit 14 compares the error rate of gFA [n + 1] with respect to gFA and β.

  (C) If RP [n + 1] is greater than or equal to RPar in step S411, the flocculant addition rate RP [n + 1] is compared with the maximum flocculant addition rate RPmax in step S414. In step S414, when the coagulant addition rate RP [n + 1] is equal to or greater than the maximum coagulant addition rate RPmax, in step S415, the output unit 16 determines that the coagulant addition rate RP [n + 1] at step S414 is an abnormal value. An alarm is output, and the process proceeds to step S303 shown in FIG.

  (D) When the flocculant addition rate RP [n + 1] is smaller than the maximum flocculant addition rate RPmax in step S414, the control unit 15 instructs to reduce the rotational speed of the flocculant stirrer 21 in step S416. . In step S417, the comparison unit 14 determines that the stirring agent rotation rate AR is larger than ARmin and smaller than ARmax, that is, when the stirring rotation number AR is within the allowable stirring rotation number, in step S419, the flocculant addition rate 2 is increased so that RP [n + 1] increases from RP [n + 1] to RP [n + 2], and the stirrer rotation speed AR is changed to an arbitrary rotation speed set in advance. The agitator motor 30 shown in FIG. 2 is controlled.

Here, in step S419, the control unit 15 controls the rotational speeds of the coagulant supply pump 29 and the coagulant stirrer 21 at the same time. However, each control is performed individually, and the causal relationship related to each other in the control method or the like. There is no. Moreover, each control method changes greatly with sludge property etc. In other words, the flocculant addition rate is 0 . The rotational speed of the flocculant supply pump 29 can be controlled to increase by 2%, and the rotational speed of the flocculating stirrer 21 can be controlled to decrease by 5% . It is also possible to control the rotational speed of the coagulant supply pump 29 so as to increase by 1% and to control the rotational speed of the coagulant stirrer 21 to decrease by 3%.

  As described above, the sludge treatment apparatus according to the modification of the first embodiment of the present invention controls the flocculant addition rate by using the flocculant supply pump 29 and the flocculant agitator 21 in combination, Adjustment and control can be performed more quickly than when only one of them is controlled. Further, fine control during the control can be easily realized by controlling with the two parameters of the rotation speed of the flocculant supply pump 29 and the rotation speed of the agitation stirrer 21. Furthermore, by using the coagulant stirrer 21 at the same time, it is possible to reduce the amount of the expensive coagulant addition rate used by the coagulant supply pump 29 in large quantities, and realize a significant cost reduction during the processing operation. it can.

(Second Embodiment)
The sludge treatment apparatus according to the second embodiment of the present invention performs sludge treatment on sludge whose properties vary. On the other hand, the sludge treatment apparatus according to the first embodiment of the present invention performs treatment on sludge having a constant property. Although the standard flocculant addition rate and the flocs floc reference area vary depending on the sludge property change, in order to perform more appropriate and accurate sludge treatment, the sludge treatment apparatus 100 is used for the reference flocculant addition rate that varies sequentially. It is necessary to control the flocculant addition rate during operation.

  Therefore, the sludge treatment apparatus 100 according to the second embodiment of the present invention calculates a new reference flocculant addition rate each time the sludge properties change, and the calculated new reference flocculant addition rate. Control the flocculant addition rate. Here, the variation in the sludge property is determined by comparing the difference in the aggregate floc measurement area with respect to each of the reference flocculant addition rates measured before and after a certain period and a preset “sludge property variation allowable value”.

  That is, if the difference in the floc floc measurement area at each reference flocculant addition rate measured before and after a certain period is greater than the `` sludge property variation allowable value '', the sludge property has changed, and the reference flocculant addition rate after a certain period is Adopted as a new reference flocculant addition rate, if it is below the “sludge property fluctuation allowable value”, the reference flocculant addition rate before a certain period is adopted as it is. The “sludge property variation allowable value” is determined based on the degree of influence on the treatment result when the sludge treatment is executed at the initial constant value, despite the change in the reference flocculant addition rate.

  Here, if the aggregated floc measurement area measured before the “certain period” is FA [n], the aggregated floc measurement area measured after the “certain period” is FA [n + 1], and the sludge property variation allowable value is χ, If │FA [n + 1] -FA [n] │ ≦ χ, it is judged that there is no change in sludge properties. If │FA [n + 1] -FA [n] │> χ, changes in sludge properties occur. The reference flocculant addition rate at that time is calculated and set as a new reference flocculant addition rate. Further, the aggregation floc measurement area FA [n] can be applied to the luminance aggregation floc measurement area bFA [n] or the gradation aggregation floc measurement area gFA [n].

  Furthermore, the “certain period” is a time zone having a certain length in which sludge properties are expected to fluctuate, and may be 3 hours or 1 day depending on the sludge treatment environment. The sludge treatment apparatus 100 continues the sludge treatment operation except in cases where the operation is forced to be interrupted due to occurrence of trouble or maintenance. Therefore, the sludge treatment apparatus 100 continuously inspects the sludge property variation at intervals of “a certain period” during operation.

  In this manner, the reference flocculant addition rate is reset every time the sludge property changes.

  An example of resetting the reference flocculant addition rate due to changes in sludge properties will be described with reference to FIGS.

  First, FIG. 14 shows a state in which the sludge property indicating the relationship between the flocculant addition rate represented by the solid line and the aggregation floc measurement area is changed to the sludge property represented by the broken line. As represented by the solid line, the reference flocculant addition rate at which the aggregated floc measurement area is minimized before sludge property change is RP corresponding to bFA [n] at which the luminance aggregated floc measurement area is minimized. However, as represented by a broken line, after the sludge property change, the luminance aggregation floc measurement area corresponding to RP is bFA [n + 1], which changes from the minimum value of the luminance aggregation floc measurement area before the sludge property change. The minimum value of the luminance aggregation floc measurement area after sludge property change is bFA '[n], and therefore the reference flocculant addition rate corresponding to bFA' [n] is RP '.

  Here, | FA [n + 1] −FA [n] | ≦ χ, and if the difference does not affect the sludge treatment after sludge property change, the reference flocculant addition rate maintains the RP and continues the operation treatment However, if │FA [n + 1] -FA [n] │> χ and the flocculant addition rate maintains the state of RP, the sludge cake moisture cannot be processed to an appropriate state. By setting 'as a new reference flocculant addition rate, it becomes possible to continue appropriate operation processing after sludge property change.

  Subsequently, | FA [n + 1] −FA [n] |> χ, and when the sludge properties change, in order to approach the new reference flocculant addition rate, the flocculant addition rate is increased or decreased. Is a problem. Focusing on the gradation flocculant addition rate shown in FIG. 14, at the reference flocculant addition rate RP, the gradation aggregation floc measurement area changes from a solid line gFA [n] to a broken line gFA [n + 1]. From the relationship of simple increase in which the coagulation floc measurement area and the coagulant addition rate are uniquely determined, bFA ′ [n] −bFA [n] ≦ 0 when gFA [n + 1] ≧ gFA [n]. Is clear. Therefore, when gFA [n + 1] ≧ gFA [n], the control unit 15 reduces the number of rotations of the flocculant supply pump 29 and decreases the flocculant addition rate, thereby providing a new reference flocculant addition rate. Control to be close to.

  Similarly, in FIG. 15, the gradation aggregation floc measurement area changes from gFA [n] to gFA [n + 1] before and after the sludge property change in a state of gFA [n + 1] ≦ gFA [n]. At that time, it is clear that bFA ′ [n] −bFA [n] ≧ 0. Therefore, when gFA [n + 1] ≦ gFA [n], the control unit 15 increases the rotation speed of the coagulant supply pump 29 and increases the coagulant addition rate, thereby providing a new reference coagulant addition rate. Control to be closer to.

  That is, as shown in FIGS. 14 and 15, before and after the sludge property change, the control unit 15 changes the rotation speed of the flocculant supply pump 29 when the gradation aggregation floc measurement area is gFA [n + 1] ≧ gFA [n]. By reducing the number of rotations of the flocculant supply pump 29 when gFA [n + 1] ≦ gFA [n], it can be controlled to maintain an appropriate constant reference flocculant addition rate. It can be seen that it is possible to carry out various sludge treatments.

  Next, the sludge treatment apparatus according to the second embodiment of the present invention will be described with reference to the flowchart of FIG. 16 for a method for calculating the reference flocculant addition rate when fluctuations in sludge properties occur.

  (A) In step S501, the calculation unit 13 calculates the luminance aggregation floc measurement area at the reference flocculant addition rate at regular intervals. In step S502, the calculation unit 13 calculates the difference between the luminance aggregation flock measurement areas before and after a certain interval. In step S503, the comparison unit 14 compares the difference calculated in step 502 with the sludge property fluctuation allowable value.

  (B) If the difference is equal to or greater than the sludge property variation allowable value in step S504, the comparison unit 14 determines that the sludge property variation has occurred, and in step S505, the calculation unit 13 determines that after a certain interval in step S502. The reference flocculant addition rate corresponding to the luminance aggregation floc measurement area is set as a new reference flocculant addition rate. In step S504, if the difference is smaller than the sludge property variation allowable value, the comparison unit 14 determines that there is no sludge property variation, and proceeds to step S502.

  As described above, the sludge treatment apparatus according to the second embodiment of the present invention restarts the new standard flocculant addition rate when the optimum sludge treatment is affected by fluctuations in the sludge properties above a certain level. By setting, optimum sludge treatment can be carried out. Further, it is possible to quickly and easily determine the increase / decrease in the rotation speed of the flocculant supply pump 29 from the comparison of the gradation aggregation floc measurement area before and after the change of the sludge property.

(Third embodiment)
As shown in FIG. 17, the sludge treatment apparatus according to the third embodiment of the present invention further includes an approximation unit 131 and a differential analysis unit 132 in the sludge treatment apparatus according to the second embodiment of the present invention. . As shown in FIG. 17, the approximation unit 131 and the differential analysis unit 132 constitute a calculation unit 13.

  The approximating unit 131 functions a graph showing the relationship between the luminance aggregation floc measurement area and the flocculant addition rate as an approximate expression.

  The differential analysis unit 132 calculates a local minimum value from the mathematical formula obtained by the approximation unit 131 as a function. As shown in FIG. 9, in the graph of the luminance aggregation floc measurement area that draws a downwardly convex curve, the minimum value is the minimum value. Therefore, the reference flocculant addition rate can be obtained by calculating the flocculant addition rate corresponding to the luminance aggregation floc measurement area that is the minimum value from the mathematical formula approximated by the approximation unit 131.

  As the sludge properties change, the differential analysis unit 132 recalculates the minimum value from the mathematical formula approximated by the approximation unit 131, so that a new reference flocculant addition rate can be determined.

  Next, a method by which the sludge treatment apparatus according to the third embodiment of the present invention calculates the reference flocculant addition rate will be described with reference to the flowchart of FIG.

  In step S <b> 601, the approximating unit 131 performs an approximate expression using a function of a graph indicating the relationship between the luminance aggregation floc measurement area and the flocculant addition rate. In step S602, the differential analysis unit 132 calculates a minimum value from the approximate expression in step S601. In step S603, the differential analysis unit 132 calculates the flocculant addition rate corresponding to the luminance aggregation floc measurement area that is the minimum value from the approximate expression obtained in step S601. In step S604, the control unit 15 sets the flocculant addition rate calculated in step S603 as the reference flocculant addition rate.

Here, steps S601 to 604 can also be applied to the reference flocculant addition rate that is newly set when the property variation occurs. That is, in step S505 shown in FIG. 16, it is possible to apply the method shown in FIG. 18, instead of applying the method shown in FIG.

  As described above, the reference flocculant addition rate calculation method according to the third embodiment of the present invention is compared with the reference flocculant addition rate calculation method according to the first embodiment of the present invention. Since the number of processes is small, and the load for calculating the gradation aggregation floc measurement area can be reduced as compared with the calculation method of the reference flocculant addition rate according to the second embodiment of the present invention, it is quick and easy. It is possible to calculate the reference flocculant addition rate.

(Fourth embodiment)
As shown in FIG. 19, the sludge treatment apparatus according to the fourth embodiment of the present invention further includes a mobile calculation unit 133 in the sludge treatment apparatus according to the third embodiment of the present invention. As shown in FIG. 19, the approximation unit 131, the differential analysis unit 132, and the mobile calculation unit 133 constitute a calculation unit 13.

  In the sludge treatment method according to the fourth embodiment of the present invention, it is assumed that the luminance aggregation floc measurement area-coagulant addition rate curve approximated by the approximation unit 131 has moved in parallel before and after the sludge property change. The assumptions applied to the fourth embodiment of the present invention are clearly valid in considering sludge treatment, considering the accumulation of empirical data.

The mobile calculation unit 133 assumes that the graph y = f (x) approximated by the approximation unit 131 is translated after the sludge property change is yb = f (xa). Moreover, the movement type | formula calculation part 133 calculates a and b by applying arbitrary two points | pieces after sludge property fluctuation | variation to the numerical formula after a parallel movement.

  Next, a method by which the sludge treatment apparatus according to the fourth embodiment of the present invention calculates a new reference flocculant addition rate after sludge property change will be described with reference to the flowchart of FIG.

  In step S701, assuming that the graph approximated by the approximating unit 131 before the sludge property change has moved in parallel after the sludge property change, the mobile calculation unit 133 calculates the graph after the parallel movement. In step S702, the differential analysis unit 132 calculates a minimum value from the approximate expression in step S701. In step S703, the differential analysis unit 132 calculates the flocculant addition rate corresponding to the luminance aggregation floc measurement area that is the minimum value from the approximate expression obtained in step S701. In step S704, the control unit 15 sets the flocculant addition rate calculated in step S703 as the reference flocculant addition rate.

  As explained above, the calculation method of the new reference flocculant addition rate after the sludge property change according to the fourth embodiment of the present invention is the method after the sludge property change according to the third embodiment of the present invention. Compared with the new calculation method of the reference flocculant addition rate, the approximation unit 131 does not need to calculate the approximate expression of luminance aggregation floc measurement area−coagulant addition rate again after the sludge property change. Can be reduced.

(Other embodiments)
As mentioned above, although this invention was described by embodiment of this invention, it should not be understood that the statement and drawing which make a part of this indication limit this invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art. It goes without saying that the present invention includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 100, 101 , 102 ... Sludge processing apparatus 11 ... Imaging part 12 ... Conversion part 13 ... Calculation part 14 ... Comparison part 15 ... Control part 16 ... Output part 17 ... Storage device 18 ... Gradation conversion part 19 ... Luminance conversion part

Claims (7)

A flocculent mixing tank for storing a sludge stock solution supplied by a sludge stock solution supply pump and a flocculant supplied by a flocculant supply pump, a flocculant stirrer for stirring the sludge stock solution and the flocculant in the coagulation mixing tank, and the coagulation agent A sludge treatment method for controlling a sludge treatment apparatus having a dehydrator in which the sludge stock solution containing agglomerated floc that is a suspended substance formed in a mixing tank is supplied through a sludge stock solution supply pipe,
The imaging unit images the aggregation floc passing through the sludge stock solution supply pipe,
The conversion unit generates a gradation binary image based on the gradation information of the image from the image of the aggregation flock captured by the imaging unit, and the image of the aggregation flock captured by the imaging unit. Generating a luminance binary image based on the luminance information of the image,
In the luminance aggregation floc average area, which is an average value of a plurality of luminance aggregation floc measurement areas calculated by the number of times set in advance by the calculation unit for the same aggregation agent addition rate, a preset value in the vicinity of the initial aggregation agent addition rate is preset. has been said to calculate the luminance flocs average area for each different flocculant addition indices in the ratio, the minimum value among the plurality of luminance floc average area and luminance flocs reference area, the luminance aggregation the flocculant rate when calculating floc reference area as a reference coagulant addition ratio to calculate the gradation floc reference area based on the reference flocculant addition rate, generated by the conversion unit at any flocculant ratio The gradation aggregation flock measurement area is calculated on the basis of the gradation binary image, and the gradation aggregation flock measurement area with respect to the gradation aggregation flock reference area is calculated. To calculate the error rate is the ratio of the minute,
The comparison unit compares the gradation aggregation floc measurement area with the gradation aggregation floc reference area, and compares the rotation speed of the flocculant stirrer with the predetermined maximum rotation speed and minimum rotation speed,
In accordance with the error rate by the calculation unit and the comparison result by the comparison unit, the control unit at least of the flocculant supply pump sets the gradation aggregation flock measurement area to the gradation aggregation flock reference area. Control the rotation speed,
Output unit, issuing an alarm when the rotational speed of the coagulant agitator falls below the maximum or speed or minimum rotation speed determined in advance,
A method for treating sludge. The sludge treatment method according to claim 1,
If the error rate is equal to or less than a predetermined error value that is a specific value set in advance, the control unit maintains the rotation rate of the flocculant supply pump to maintain the flocculant addition rate ,
When the gradation aggregation floc measurement area is larger than the gradation aggregation floc reference area and the error rate is larger than the error default value, the control unit reduces the rotation speed of the aggregation agent supply pump. by the value previously set the flocculant ratio is reduced,
When the gradation aggregation floc measurement area is smaller than the gradation aggregation floc reference area and the error rate is larger than the error default value, the control unit increases the rotation speed of the aggregation agent supply pump. is increased by a preset value the flocculant constant,
A method for treating sludge. The sludge treatment method according to claim 2 ,
If the previous SL controller reduces the pre Symbol flocculant addition rate, in the case of less than the minimum flocculant addition rate flocculant ratio after reduction preset an alarm output unit, flocculant after the reduction the rate is the minimum flocculant greater than additive rate is lower the rotational speed of the coagulant supply pump before Symbol controller,
If the previous SL controller increases the previous SL flocculant ratio, if flocculant rate after the increase is smaller than the preset flocculant constant agitation reference value increases the rotation speed of the coagulant supply pump When the increased flocculant addition rate is equal to or greater than the flocculant addition rate stirring reference value and smaller than the maximum flocculant addition rate, the control unit further reduces the rotational speed of the flocculant stirrer.
A method for treating sludge. A sludge treatment method according to any one of claims 1 to 3,
When the control unit increases the flocculant constant, if flocculant rate after increasing over more than up to flocculant ratio, the output unit is issued a warning,
A method for treating sludge. The sludge treatment method according to claim 1 ,
When the error rate is equal to or less than a predetermined error value that is a specific value set in advance, the control unit maintains the rotation speed of the flocculant stirrer,
When the gradation aggregation floc measurement area is smaller than the gradation aggregation floc reference area and the error rate is larger than the error default value, the control unit decreases the rotation speed of the flocculant stirrer,
When the gradation aggregation floc measurement area is larger than the gradation aggregation floc reference area and the error rate is larger than the error default value, the control unit increases the rotation speed of the flocculant stirrer.
A method for treating sludge. A sludge treatment method according to any one of claims 1 to 5,
The aggregated floc measurement area is the total area of the entire aggregated floc displayed in the image .
A method for treating sludge. The sludge treatment method according to any one of claims 1 to 6,
The aggregate floc measurement area is an area per unit aggregate floc obtained by dividing the total area of the entire aggregate floc displayed in the image by the number of aggregate flocs displayed in the image.
The calculation unit further calculates the number of aggregated flocs displayed in the image and the area per unit aggregated floc.
Sludge processing how, characterized in that.

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