JP2005007338A - Method and apparatus for controlling injection of flocculant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for controlling the injection of a flocculant, wherein the amount of the flocculant to be added is adjusted by taking a picture of the flocculated state of a floc in an original liquid. <P>SOLUTION: The picture of the floc is taken by setting a television camera (15) at an inspection window (14) on an original liquid supplying pipe (13) connected to a dehydrator (12). The analyzable area per one floc is integrated by binarizing the taken picture by using an arithmetic unit (17). The integrated area is compared with a preset reference area by sequencer proportional control (22). The number of revolution of a flocculant injecting pump (9) is controlled on the basis of the formed state of the floc. Since the flow velocity in the pipe (13) is low and flocs are hardly superimposed on one another, an accurate picture can be taken. Since the picture of the floc itself to be supplied to the dehydrator (12) is taken, the analyzable area of the floc in a stabilized state can be obtained. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００２４】
表１はシーケンサー比例制御に入力するフロックの基準面積の解析データであって、凝集混和槽５の原液流入量（ｍ^３）に対するあらかじめ設定する凝集剤添加率（％）を、原液流入量１０ｍ^３に対する凝集剤添加率を０．２％、０．３％、０．４％の３段階に設定した。このデータに基づき、原液中の懸濁物質を凝集させ、フロックを撮影して、凝集汚泥のフロックを大きい順に２０点を平均した。そのフロック画像の面積データは、表１のとおりである。あらかじめ汚泥流入量に対する凝集剤の注入率を設定し、その原液中のフロック１個当たりの平均面積を、フロックの基準面積としてシーケンサー比例制御２２に入力してある。
【００２５】
シーケンサー比例制御２２には凝集剤注入率を増減させる比例設定値があらかじめ入力してあり、フロックの１ヶ当たりの平均解析面積が基準面積より大きい場合は、現状の設定値から凝集剤添加率を０．１％少なくし、平均解析面積が基準面積より小さい場合、現状の設定値から凝集剤添加率を０．１％多くするようにしてある。シーケンサー比例制御２２は演算装置１７から送信されるフロックの１ヶ当たりの平均解析面積と、設定した基準面積を比較演算し、凝集剤注入ポンプ９からの凝集剤の注入率を制御する。凝集剤注入率の上限値と下限値が設定してあり、この発明の実施例では、０．３〜１．０％、好ましくは、０．５〜０．７％としてある。凝集剤注入ポンプ９の回転数が上限値あるいは下限値に到達した時に、シーケンサー比例制御２２に併設した異常信号装置２３が、異常信号を出すようにしてある。原液の泥の質以外の要素、または全く異なった液の混入などの要素が影響を及ぼし、調整不能となっていることが考えられ、技術者が原因を調査する。なお、異常信号を警報としてもよいものである。
【００２６】
そして、凝集混和槽５に設置した撹拌機１１は、所定の回転数で撹拌するようにしてあり、この発明の実施例では、４０ｒｐｍとしてある。シーケンサー比例制御２２にはフロックの平均解析面積に対応して、凝集混和槽５に設置した撹拌機１１の可変速駆動機１０の回転数を切替える規定値（３〜５ｒｐｍ）が設定してある。シーケンサー比例制御２２は凝集剤注入ポンプ９からの凝集剤の注入率を制御すると共に、平均解析面積と基準面積を比較して、撹拌機１１の回転数を制御する。この実施例では、解析面積が基準面積より大きい場合は、撹拌機１１の回転数を３〜５ｒｐｍ規定値より増速させる。解析面積が基準面積より小さい場合は、撹拌機１１の回転数を３〜５ｒｐｍ規定値より減速させる。
【００２７】
撹拌機１１の回転数は上限値と下限値が設定してあり、撹拌機１１の回転数が規定値の上限値に上昇あるいは下限値に降下した時には、シーケンサー比例制御２２に併設した異常信号装置２３が異常信号を発するようにしてある。撹拌機１１の回転数の上限値と下限値の設定は、凝集混和槽５の大きさ、原液流量、及び濃度により異なるものであり、適宜設定すればよいものである。演算装置１７のフロックの平均面積の演算値に基づき、シーケンサー比例制御２２はフロックの平均面積が規定値になるように、凝集剤注入ポンプ９からの注入率と撹拌機１１の回転数を制御する。凝集剤注入率を変化させた場合、フロックの粒径が変化するまでの数分間の時間を考慮する。この発明の実施例では、２〜３分後に再びテレビカメラ１５で撮像するが、凝集混和槽５の容量により待機時間が変わるものである。
【００２８】
この発明に係る凝集剤注入制御装置は上記のように構成してあり、その制御装置による凝集剤注入制御方法について説明すると、先ず、原液中の懸濁物質量の変動に対する凝集剤注入率の比例制御によるコントロール方法は、フロックの１ヶ当たりの解析面積（平均面積）が基準面積より大きい場合、凝集剤注入率の比例設定値を変更させ、凝集剤注入率を０．１％少なくし、２〜３分間待ち再測定する。まだ、解析面積が基準面積より大きい場合、上記操作を繰り返す。凝集剤注入率が下限値の０．３％に達した時、現状を維持しながら、異常信号を出す。逆に、フロックの１ヶ当たりの平均解析面積が基準面積より小さい場合は、凝集剤の注入率０．１％を増加させ、２〜３分間待ち再測定する。凝集剤の注入率が上限値の１．０％になった時は、現状維持しながら異常信号を出す。異常信号が表示され、或いは警報があった時には、技術者が原因を調査する。平均解析面積が基準面積の範囲内（０．３〜１．０％）にある時には、現時点の凝集剤注入率を維持しながら、テレビカメラ１５で連続撮影してフロックの状態を監視する。
【００２９】
脱水機１２に定量の原液を供給して比例制御を使わない場合には、フロックの平均解析面積が基準面積より大きくなった時に、凝集剤供給量を現状より設定値０．１％少なくし、２〜３分間待ち再測定する。まだ平均解析面積が基準面積より大きい時は、上記操作を繰り返し、凝集剤注入率の下限値０．３％に達した場合は現状維持しながら異常信号を出す。逆に、平均解析面積が基準面積より小さい場合は、凝集剤注入ポンプ９の回転数を増加させ、凝集剤注入率を０．１％増加させて２〜３分間待ち再測定する。凝集剤の注入率が上限値の１．０％となった時には、凝集剤の注入率を維持しながら異常信号を出す。異常信号が表示され、或いは警報があった時には、技術者が原因を調査する。
【００３０】
凝集剤注入率の比例制御と撹拌機回転によるコントロール方法は、平均解析面積が基準面積より大きい場合には、凝集剤注入比率を規定量の０．１％を減少させ、２〜３分間待ち再測定する。まだ平均解析面積が基準面積より大きい時には、撹拌機１１の回転数は所定の回転数４０ｒｐｍを維持しながら、凝集剤注入比率を０．１％減少させる。上記の操作を繰り返しまだ平均解析面積が基準面積より大きい場合は、撹拌機１１の回転数を規定値の３〜５ｒｐｍ速める。弱い大きいフロックは、撹拌機１１の回転数を増やして小さくし、凝集剤を撹拌混合してフロックを強くする。撹拌機１１の回転数が上限値となった時には、異常信号を出す。逆に平均解析面積が基準面積より小さい場合には、凝集剤の注入率を設定値の０．１％増加させ、２〜３分間待ち再測定する。凝集剤の注入率が上限値１．０％、になった場合、撹拌機１１の回転を規定値の３〜５ｒｐｍ下げる。撹拌機１１の回転数は下限値を設定しておき、下限値に達してもフロックが小さい場合は異常信号を出す。異常信号が表示され、或いは警報があった時には、技術者が原因を調査する。
【００３１】
【発明の効果】
以上のように、この発明の凝集剤注入制御方法並びにその制御装置は、凝集混和槽から出た配管ラインで懸濁物質のフロックを面積で撮影するので、フロックの重なりが少なくなり、信頼性の高いフロックの解析面積が得られる。配管ラインの流速も適度に下がり、タンク圧入を行うので脈動も少なくなり、テレビカメラの撮影が容易となる。即ち、凝集混和槽等でフロックを撮影する従来技術にあっては、槽の奥行きによるフロックの重なりと、撹拌機の回転により正確な撮影ができない欠点がある。そして、凝集状態をフロックの数で評価する従来装置は、濃度が変わればフロック数が変わり、凝集混和槽ではフロックの重なりがあり、正確な撮影ができないものであるが、この発明に係る凝集剤注入制御方法にあっては、脱水機の原液供給管に含まれるフロックの大きさを撮影し、フロックの２値画像からのフロック１個当たりの平均面積を計算し、その平均解析面積とあらかじめ設定したフロックの基準面積と比較して適正値を計算し、フロックの形成状況に基づき凝集剤の注入率を制御するもので、フロック同士の重なりによる測定誤差が解除され、安定したフロックの状態で解析面積が測定できる。脱水機に供給するフロックそのものを撮影するので信頼性が高くなる。
【００３２】
凝集剤注入制御方法を実施するための制御装置は、原液供給管の検視窓にテレビカメラと、撮影したフロック１個当たりの平均解析面積を積算する演算装置と、平均解析面積と基準面積を比較して指令信号を発信するシーケンサー比例制御と、指令信号に基づき作動させる凝集剤注入ポンプを設けたので、配管内の流速は凝集混和槽の撹拌機によるフロックの撹拌速度ほど速くなく、正確にフロックの撮影が行える。そして、シーケンサー比例制御に異常信号装置を併設し、凝集剤注入率の上限値と下限値で異常信号を発信させるので、調整不可能となる状態が察知でき、技術者の原因の調査が可能となり、凝集剤注入制御装置の自動化が行なえる。
【図面の簡単な説明】
【図１】この発明に係る凝集剤注入制御装置に用いる機器類の構成図である。
【図２】この発明に係る凝集剤注入制御装置の画像解析制御フローである。
【図３】テレビカメラで撮影した懸濁物質のフロックの画像であって、図３（ａ）は小さいフロック、図３（ｂ）は最適フロック、図３（ｃ）は過大なフロックを示す。
【符号の説明】
５ 凝集混和槽
９ 凝集剤注入ポンプ
１１ 撹拌機
１２ スクリュープレス
１３ 原液供給管
１４ 検視窓
１５ テレビカメラ
１７ 演算装置
２２ シーケンサー比例制御
２３ 異常信号装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flocculant injection control method for adjusting the flocculant injection rate by photographing the agglomeration state of clean water sludge, sewage sludge, industrial wastewater sludge, and the like, and an improvement of the control device.
[0002]
[Prior art]
Conventionally, a stock solution containing suspended solids has added flocculants to form flocs of suspended solids to reduce the water content of dehydrated sludge. As a control device for the aggregated state of suspended substances in the stock solution, the aggregated state of suspended substances in the coagulation mixing tank is photographed, or a part of the stock solution and the flocculant is supplied to a small test tank. A sludge agglomeration processing apparatus that captures a binarized image of flocs obtained by agglomerating suspended substances and analyzes the agglomerated state of the suspended solids by the number of flocs is known as described in Patent Document 1, for example. is there. Also, a control device that obtains the average particle size of the aggregate group from the binarized image is known as described in Patent Document 2.
[0003]
[Patent Document 1]
Japanese Patent No. 3136554 (paragraph numbers 0012 to 0016, FIG. 1)
[Patent Document 2]
Japanese Examined Patent Publication No. 6-61410 (Claim 1, FIG. 1)
[0004]
[Problems to be solved by the invention]
The conventional sludge flocculation treatment apparatus is not affected by flocs, and has an advantage that the flocculation state can be automatically measured online and the addition amount can be automatically adjusted. However, in the case where the aggregation state of the suspended substance is evaluated by the number of flocs, if the concentration is changed, the floc number is changed even when the flocculant is added at the same rate. As for the means for measuring the particle size, the floc shape is irregular and it is difficult to evaluate the particle size. The flocculent mixing tank and the test tank have floc overlap due to the depth of the tank, so that accurate photographing cannot be performed. Since the agitator is rotating, the flock moves quickly, and there is a disadvantage that photography cannot be performed. The present invention provides a flocculant injection control method and a control apparatus for photographing a floc size in a pipe in which a TV camera is disposed in a raw material piping line, and flocs are overlapped and the flow rate is reduced to an appropriate flow rate without pulsation. provide.
[0005]
[Means for Solving the Problems]
The flocculant injection control method according to the present invention is a sludge treatment apparatus that adds flocculant to a stock solution in a flocculent mixing tank to form a floc of suspended solids and supplies the stock solution to a dehydrator. The size of the floc in the stock solution supply pipe is taken, the luminance signal is converted into an electric signal, the floc magnitude is binarized from the electric signal, and one floc from the binary image of the floc The average analysis area is calculated, the average analysis area is compared with the preset floc reference area, the appropriate value is calculated, and the proportional setting value flocculant injection rate is controlled based on the floc formation status. The flow rate of the stock solution in the supply pipe is appropriately reduced, and the thickness of the liquid layer of the stock solution is also reduced. Overlap between flocs is reduced, and accurate shooting is possible. Furthermore, since the floc supplied to the dehydrator is photographed, the reliability is improved.
[0006]
According to the second aspect of the flocculant injection control method, the floc in the stock solution supply pipe is photographed every predetermined time, and the binarized data is averaged several times, and the analysis area of the floc is set in advance. It calculates the appropriate value compared with the standard area, changes the coagulant injection rate by increasing or decreasing the rotation speed of the coagulant injection pump, and measures again after a few minutes. Is released, and the analysis area can be measured in a stable flock state.
[0007]
The invention according to claim 3 of the flocculant injection control method changes the flocculant injection rate with respect to fluctuations in the amount of suspended solids contained in the stock solution, compares the average analysis area of flocs with the reference area, and calculates the average analysis. When the area is larger than the reference area, the rotational speed of the flocculant injection pump is decreased, and when the average analysis area reaches the upper limit of the reference area, the current flocculant injection rate is maintained and the average analysis area is still Is larger than the reference area, and when this operation is repeated and the coagulant injection rate reaches the set lower limit value, an abnormal signal is output while maintaining the rotational speed of the coagulant injection pump. It is possible to automate the flocculant injection control method.
[0008]
The invention according to claim 4 of the flocculant injection control method changes the flocculant injection rate with respect to fluctuations in the amount of suspended solids in the stock solution, compares the average analysis area of the floc and the reference area, and the average analysis area is When the average area is less than the lower limit of the reference area, the current coagulant injection rate is maintained and the analysis area is still the reference area. When the coagulant injection rate reaches a set upper limit value by repeating this operation smaller, an abnormal signal is output while maintaining the rotational speed of the coagulant injection pump.
[0009]
The invention according to claim 5 of the flocculant injection control method compares the average analysis area of the flock with the reference area when supplying a constant stock solution amount to the dehydrator, and if the average analysis area is larger than the reference area, When the average injection area is within the upper limit of the reference area, the current coagulant injection rate is maintained, and the above procedure is repeated to reach the lower limit set by the coagulant injection rate. When this occurs, an abnormal signal is output while maintaining the rotation speed of the flocculant injection pump.The abnormal signal may cause mixing of liquids with different properties of the stock solution, affecting the elements of the mud and cannot be adjusted. Can be detected, and the cause of the engineer can be investigated.
[0010]
The invention according to claim 6 of the flocculant injection control method compares the average analysis area of the flock with the reference area when supplying a constant stock solution amount to the dehydrator, and if the average analysis area is smaller than the reference area, When the average analysis area reaches within the lower limit of the reference area by increasing the rotation speed of the agent injection pump, the current coagulant injection rate is maintained, and the above operation is repeated to set the upper limit of the coagulant injection rate When the value is reached, an abnormal signal is output while maintaining the rotational speed of the coagulant injection pump.
[0011]
According to the seventh aspect of the flocculant injection control method, when the calculated average analysis area of flocs is larger than the reference area, the flocculant injection rate is decreased and at the same time the rotation speed of the stirrer of the flocculent mixing tank is increased. When the average analysis area reaches within the upper limit of the reference area, the current coagulant injection rate and the rotation speed of the stirrer are maintained, and the above operation is repeated until the coagulant injection rate is set to the lower limit value set. When it reaches, it will give an abnormal signal while maintaining the rotation speed of the flocculant injection pump and the stirrer, and the floc may be weak and large, but rather it is better to increase the rotation of the stirrer and make a small floc There is also. If the floc is strong but too small, the rotation speed of the stirrer can be reduced and the floc can be increased.
[0012]
The invention according to claim 8 of the flocculant injection control method increases the flocculant injection rate when the calculated floc analysis area is smaller than the reference area, and simultaneously decreases the rotation speed of the stirrer of the flocculent mixing tank, When the analysis area of the floc reaches the lower limit of the reference area, while maintaining the current flocculant injection rate and the rotation speed of the stirrer, the above operation is repeated and the flocculant injection rate reaches the lower limit set. When this occurs, an abnormal signal is output while maintaining the rotation speed of the flocculant injection pump and the agitator.
[0013]
The invention according to claim 9 of the flocculant injection control device for carrying out the above control method supplies the stock solution and the flocculant to the sealed flocculent mixing tank, and the flocs of the suspended substances contained in the stock solution are supplied. In the stock solution supply device that forms and feeds the stock solution to the dehydrator at the tank pressure of the agglomeration tank, an inspection window is provided in the stock solution supply pipe connected to the dehydrator, and the size of the floc of suspended solids is photographed in the inspection window And a computing device that binarizes the captured flock images and integrates the average analysis area per floc, and compares the average analysis area of the integrated flock with a preset reference area. In addition, a sequencer proportional control that sends a command signal based on the flock formation status and a flocculant injection pump that controls the rotation speed based on the command signal are provided. No fast as stirring rate of floc by agitator, it can be performed accurately captured floc. The pulsation of the undiluted solution is reduced by the tank press-fitting.
[0014]
The invention according to claim 10 of the flocculant injection control device changes the flocculant injection rate of the proportional setting value with respect to the fluctuation of the suspended solids contained in the stock solution, and performs an average analysis per floc of the stock solution supply pipe Comparing the area with the reference area to control the rotation speed of the flocculant injection pump, and an abnormal signal device is added to the sequencer proportional control to send an abnormal signal at the upper and lower limits of the flocculant injection rate. Thus, it is possible to detect a state in which adjustment is impossible due to the abnormal signal, the cause of the engineer can be investigated, and the flocculant injection control device can be automated.
[0015]
According to the eleventh aspect of the flocculant injection control device, when supplying a constant stock solution amount to the dehydrator, the average analysis area of the floc of the stock solution supply pipe is compared with the reference area, and the rotation speed of the flocculant injection pump is compared. And an abnormal signal device in the sequencer proportional control, and an abnormal signal may be transmitted at the upper limit value and the lower limit value of the coagulant injection rate, and managed between the upper limit value and the lower limit value, The cause of the engineer can be investigated.
[0016]
The invention according to claim 12 of the flocculant injection control device compares the average analysis area of the floc and the reference area, and when the average analysis area is larger than the reference area, the rotation speed of the flocculant injection pump is increased, While reducing the rotation speed of the stirrer in the coagulation mixing tank, when the average analysis area of the floc is smaller than the reference area, the rotation speed of the flocculant injection pump is decreased and at the same time the rotation speed of the stirrer is increased. Even if it is large, a weak floc can be strengthened, and a floc that is too small can be enlarged. It can reduce the amount of polymer and strengthen the stirring.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The flocculant injection control method and the control device thereof according to the present invention are configured as described above, and set in advance a proportional value of the flocculant injection rate with respect to fluctuations in the stock solution supply amount and concentration, and The flocs in the stock solution extracted with the tank pressure are imaged, the average area of the flocs of suspended solids is calculated, and is input in advance to the computer as a reference area. Then, the stock solution supplied to the dehydrator from the coagulation / mixing tank is imaged from a sight tube provided in the piping line, the size of the floc is photographed once every 15 to 30 seconds, and the luminance signal is converted into an electrical signal. This flock image is binarized by an arithmetic device, averaged four times of binarized data (data for 1 to 2 minutes), and polymer increase / decrease is evaluated by a computer. Immediately after changing the flocculant supply amount, wait for 2 to 3 minutes before starting to shoot. By comparing the average analysis area per floc calculated in this way with the reference area, the flocculant injection rate is varied according to the average analysis area, and proportional control of the flocculant injection rate with respect to the floc in the stock solution I do.
[0018]
If the concentration changes, the number of flocs changes even with the addition of the same rate of flocculant, so the aggregated state of the suspended matter is evaluated by the floc area. If analysis is performed using the size of the floc, the size of the floc contained in the pipe can be binarized more accurately. Even when the stock solution is supplied at a constant amount, the average analysis area per floc is compared with the reference area, and the flocculant injection rate is varied according to the average analysis area. Further, in the control method using the coagulant proportional injection and the rotation of the stirrer, the flocculant injection ratio is increased or decreased by a specified amount, and the rotation speed of the stirrer stirred at a predetermined speed is changed. When the coagulant injection rate and the rotation speed of the stirrer reach the upper limit value or the lower limit value, an abnormal signal is issued and the technician investigates the situation.
[0019]
【Example】
The flocculant injection control device according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of equipment used in the flocculant injection control device, and a stock solution containing suspended substances is provided with an agitator 1. The stock solution is stored in the stock solution storage tank 2, and a fixed amount of the stock solution is press-fitted from the press-fit pipe 4 to the bottom of the sealed coagulation and mixing tank 5 by the stock solution supply pump 3. The flocculant is stored in a polymer flocculant dissolution tank 7 provided with a stirrer 6 and added to the stock solution of the press-fitting pipe 4 by a variable capacity flocculant injection pump 9 in the range of 0.3 to 1.0%. And it supplies to the tank bottom of the aggregation mixing tank 5. FIG. The flocculant injection pump 9 can increase or decrease the addition rate of the flocculant stepwise by 0.1%. The flocculant may be directly supplied to the flocculent mixing tank 5. The agglomeration and mixing tank 5 is provided with a stirrer 11 connected to a variable speed driving machine 10, and the stock solution and the polymer flocculant are usually stirred at a speed of 40 rpm, and the speed is increased and decreased at 3 to 5 rpm stepwise. Is possible.
[0020]
As shown in FIG. 1, a stock solution supply pipe 13 is connected to the upper part of the agglomeration mixing tank 5 to feed a stock solution in which flocks are formed to a screw press 12 of a dehydrator. Utilizing the press-fitting pressure of the stock solution supply pump 3 into the coagulation mixing tank 5, the stock solution is pressed into the screw press 12 at the tank pressure of the coagulation mixing tank 5 so that the flocs of the aggregated suspended solids are not broken by pulsation. is there. An inspection window 14 is provided for photographing the state of flocs of the suspended substance aggregated in the stock solution supply pipe 13. A television camera 15 is installed at a position 30 to 40 cm away from the inspection window 14 of the stock solution supply pipe 13. FIG. 2 is an image analysis control flow of the flocculant injection control device. The size of the floc of the suspended substance in the stock solution supply pipe 13 is photographed once every 15 to 30 seconds by the TV camera 15, and the luminance signal is obtained. Convert to digital signal. The luminance information of the electrical signal is transmitted to the controller 16, and the controller 16 transmits the flock image to the arithmetic device 17. The image brightness information of the flock group transmitted from the TV camera 15 is stored in the image board 18 of the arithmetic unit 17. This image information is binarized by the binarization circuit 19 according to the luminance level.
[0021]
The binarized flock group image information is input to the average area calculation circuit 20, and the binarized data is averaged four times (1-2 minutes data) to obtain the average value of the flock group area. The average area per floc is defined as the average analysis area on one screen. The reason for the number of times of measurement is that there is an overlap between flocs in a single measurement and there is a measurement error. The more the number of measurements, the more accurate it is. However, for the purpose of fast operation, about 4 times is appropriate. The processing result of the average area calculation circuit 20 is sent from the calculation device 17 to the signal converter 21, converts the digital signal into an analog signal, and transmits it to the sequencer proportional control 22. In the sequencer proportional control 22, flocs in the stock solution extracted in advance from the coagulation mixing tank 5 are photographed, and the average area of the suspended flocs is calculated and input to the sequencer proportional control 22 as a reference area. And the proportional value of the injection rate of the flocculant with respect to the fluctuation | variation of the amount of suspended solids in a stock solution and the fluctuation | variation of a density | concentration is preset.
[0022]
3 (a), 3 (b), and 3 (c) are floc images of the suspended matter taken with the television camera 15, and the image in FIG. 3 (a) is a small floc, and the addition rate of the flocculant Or the rotational speed of the stirrer must be slowed down to obtain the optimum floc of FIG. It is also conceivable to reduce the rotational speed of the stirrer while increasing the addition rate of the flocculant. The image in FIG. 3 (c) is an excessive floc, and it is necessary to reduce the addition rate of the flocculant or to increase the rotation speed of the stirrer to obtain the optimum floc in FIG. 3 (b). In this case, it is also conceivable to increase the rotational speed of the stirrer while reducing the addition rate of the flocculant.
[0023]
[Table 1]

[0024]
Table 1 shows analysis data of the standard area of floc input to the sequencer proportional control, and the flocculant addition rate (%) set in advance with respect to the stock solution inflow amount (m ³ ) of the coagulation mixing tank 5 is determined as the stock solution inflow amount 10 m ^3. The flocculant addition rate was set to three levels of 0.2%, 0.3%, and 0.4%. Based on this data, suspended substances in the stock solution were agglomerated, flocs were photographed, and the flocs of agglomerated sludge were averaged over 20 points in descending order. The area data of the flock image is as shown in Table 1. The injection rate of the flocculant with respect to the sludge inflow rate is set in advance, and the average area per floc in the stock solution is input to the sequencer proportional control 22 as the floc reference area.
[0025]
In the sequencer proportional control 22, a proportional set value for increasing / decreasing the flocculant injection rate is input in advance, and when the average analysis area per floc is larger than the reference area, the flocculant addition rate is determined from the current set value. When the average analysis area is smaller than the reference area by 0.1%, the flocculant addition rate is increased by 0.1% from the current set value. The sequencer proportional control 22 compares the average analysis area per floc transmitted from the arithmetic unit 17 with the set reference area, and controls the injection rate of the flocculant from the flocculant injection pump 9. An upper limit value and a lower limit value of the flocculant injection rate are set, and in the embodiment of the present invention, the upper limit value and the lower limit value are set to 0.3 to 1.0%, preferably 0.5 to 0.7%. When the rotation speed of the coagulant injection pump 9 reaches the upper limit value or the lower limit value, the abnormality signal device 23 provided in the sequencer proportional control 22 outputs an abnormality signal. Factors other than the quality of the mud in the stock solution or factors such as mixing of completely different fluids may have affected and may not be adjustable, and the engineer will investigate the cause. The abnormal signal may be used as an alarm.
[0026]
And the stirrer 11 installed in the coagulation mixing tank 5 is made to stir at predetermined rotation speed, and is 40 rpm in the Example of this invention. The sequencer proportional control 22 is set with a specified value (3 to 5 rpm) for switching the rotation speed of the variable speed drive 10 of the stirrer 11 installed in the coagulation mixing tank 5 corresponding to the average analysis area of flocs. The sequencer proportional control 22 controls the injection rate of the flocculant from the flocculant injection pump 9 and compares the average analysis area with the reference area to control the rotation speed of the stirrer 11. In this embodiment, when the analysis area is larger than the reference area, the rotational speed of the stirrer 11 is increased from a specified value of 3 to 5 rpm. When the analysis area is smaller than the reference area, the rotational speed of the stirrer 11 is decelerated from a specified value of 3 to 5 rpm.
[0027]
An upper limit value and a lower limit value are set for the rotation speed of the stirrer 11, and when the rotation speed of the stirrer 11 rises to the upper limit value of the specified value or falls to the lower limit value, an abnormal signal device attached to the sequencer proportional control 22 23 emits an abnormal signal. The setting of the upper limit value and the lower limit value of the rotation speed of the stirrer 11 varies depending on the size of the agglomeration mixing tank 5, the stock solution flow rate, and the concentration, and may be set as appropriate. The sequencer proportional control 22 controls the injection rate from the coagulant injection pump 9 and the rotation speed of the stirrer 11 so that the average area of the floc becomes a specified value based on the calculated value of the average area of the floc of the arithmetic unit 17. . When the flocculant injection rate is changed, a time of several minutes until the floc particle size changes is taken into consideration. In the embodiment of the present invention, the image is picked up again by the television camera 15 after 2 to 3 minutes, but the waiting time varies depending on the capacity of the agglomeration mixing tank 5.
[0028]
The flocculant injection control device according to the present invention is configured as described above, and the flocculant injection control method by the control device will be described. First, the proportion of the flocculant injection rate to the variation in the amount of suspended solids in the stock solution When the analysis area (average area) per floc is larger than the reference area, the proportional setting value of the flocculant injection rate is changed to reduce the flocculant injection rate by 0.1%. Wait ~ 3 minutes and remeasure. If the analysis area is still larger than the reference area, the above operation is repeated. When the coagulant injection rate reaches 0.3% of the lower limit, an abnormal signal is issued while maintaining the current state. On the contrary, when the average analysis area per floc is smaller than the reference area, the flocculant injection rate is increased by 0.1% and the measurement is waited for 2 to 3 minutes. When the injection rate of the flocculant reaches 1.0% of the upper limit, an abnormal signal is issued while maintaining the current state. When an abnormal signal is displayed or there is an alarm, an engineer investigates the cause. When the average analysis area is within the range of the reference area (0.3 to 1.0%), the TV camera 15 is continuously photographed to monitor the flock state while maintaining the current flocculant injection rate.
[0029]
When supplying a fixed amount of undiluted solution to the dehydrator 12 and not using proportional control, when the average analysis area of the floc becomes larger than the reference area, the flocculant supply amount is reduced by 0.1% from the current state, Wait 2-3 minutes and remeasure. When the average analysis area is still larger than the reference area, the above operation is repeated, and when the lower limit of the flocculant injection rate reaches 0.3%, an abnormal signal is output while maintaining the current state. Conversely, when the average analysis area is smaller than the reference area, the rotation speed of the coagulant injection pump 9 is increased, the coagulant injection rate is increased by 0.1%, and the measurement is waited for 2 to 3 minutes. When the coagulant injection rate reaches 1.0% of the upper limit, an abnormal signal is output while maintaining the coagulant injection rate. When an abnormal signal is displayed or there is an alarm, an engineer investigates the cause.
[0030]
When the average analysis area is larger than the reference area, the control method by proportional control of the flocculant injection rate and the agitator rotation reduces the flocculant injection ratio by 0.1% of the specified amount and waits for 2 to 3 minutes. taking measurement. When the average analysis area is still larger than the reference area, the flocculant injection ratio is decreased by 0.1% while maintaining the rotation speed of the agitator 11 at a predetermined rotation speed of 40 rpm. If the average analysis area is still larger than the reference area by repeating the above operation, the rotational speed of the stirrer 11 is increased by 3 to 5 rpm, which is a specified value. The weak large floc is made small by increasing the number of rotations of the stirrer 11, and the floc is strengthened by stirring and mixing the flocculant. When the rotational speed of the agitator 11 reaches the upper limit value, an abnormal signal is output. On the contrary, when the average analysis area is smaller than the reference area, the injection rate of the flocculant is increased by 0.1% of the set value, and the measurement is waited again for 2 to 3 minutes. When the injection rate of the flocculant reaches the upper limit value of 1.0%, the rotation of the stirrer 11 is lowered by the specified value of 3 to 5 rpm. A lower limit value is set for the rotational speed of the agitator 11, and an abnormal signal is output if the floc is small even if the lower limit value is reached. When an abnormal signal is displayed or there is an alarm, an engineer investigates the cause.
[0031]
【The invention's effect】
As described above, since the flocculant injection control method and the control apparatus according to the present invention photograph the flocs of suspended solids in the area of the piping line coming out of the flocculent mixing tank, the floc overlap is reduced and the reliability is improved. High flock analysis area can be obtained. The flow speed of the piping line is also reduced moderately and tank press-fitting reduces pulsation, making it easier to shoot with a TV camera. In other words, the conventional technique for photographing flocs in an agglomeration mixing tank or the like has a drawback that accurate photographing cannot be performed due to floc overlap due to the depth of the tank and rotation of the stirrer. The conventional apparatus for evaluating the aggregation state by the number of flocs changes the number of flocs if the concentration changes, and flocs overlap in the agglomeration mixing tank, so that accurate photographing cannot be performed. In the injection control method, the size of the floc contained in the stock solution supply pipe of the dehydrator is photographed, the average area per floc is calculated from the binary image of the floc, and the average analysis area is set in advance. Compared with the standard area of the flocs calculated, an appropriate value is calculated, and the injection rate of the flocculant is controlled based on the floc formation status. The measurement error due to the overlap of flocs is released, and analysis is performed in a stable floc state. The area can be measured. Since the flock supplied to the dehydrator is photographed, the reliability increases.
[0032]
The control device for carrying out the flocculant injection control method compares the average analysis area and the reference area with a television camera and an arithmetic unit that accumulates the average analysis area per captured flock in the inspection window of the stock solution supply pipe Since a sequencer proportional control that sends a command signal and a flocculant injection pump that operates based on the command signal are provided, the flow rate in the pipe is not as fast as the floc stirring speed of the stirrer in the flocculent mixing tank, Can be taken. In addition, an abnormal signal device is added to the sequencer proportional control, and an abnormal signal is transmitted with the upper and lower limits of the coagulant injection rate, so it is possible to detect the situation where adjustment is impossible, and the cause of the engineer can be investigated. The flocculant injection control device can be automated.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of devices used in a flocculant injection control device according to the present invention.
FIG. 2 is an image analysis control flow of the flocculant injection control device according to the present invention.
FIGS. 3A and 3B are images of suspended flocs taken with a television camera, in which FIG. 3A shows a small floc, FIG. 3B shows an optimal floc, and FIG. 3C shows an excessive floc.
[Explanation of symbols]
5 Coagulation Mixing Tank 9 Coagulant Injection Pump 11 Stirrer 12 Screw Press 13 Stock Solution Supply Pipe 14 Viewing Window 15 Television Camera 17 Computing Device 22 Sequencer Proportional Control 23 Abnormal Signal Device

Claims (12)

In the sludge treatment apparatus that adds flocculant to the stock solution in the coagulation mixing tank (5) to form suspended substance flocs and supplies the stock solution to the dehydrator (12), the stock solution is supplied to the dehydrator (12). The size of the floc in the stock solution supply pipe (13) is photographed, the luminance signal is converted into an electric signal, the floc magnitude is binarized from the electric signal, and one floc from the binary image of the floc The average analysis area is calculated, the average analysis area is compared with a preset standard area of flocs, an appropriate value is calculated, and the flocculant injection rate of the proportional setting value is controlled based on the formation state of flocs A control method for injecting the flocculant The flocs in the stock solution supply pipe (13) are photographed every predetermined time, and the binarized data is averaged for several times, and an appropriate value is compared with the analysis area of the flocs and a preset reference area. The coagulant injection according to claim 1, wherein the coagulant injection rate is changed, the coagulant injection rate of the proportional set value is changed by increasing or decreasing the rotation speed of the coagulant injection pump (9), and remeasured after a few minutes. Control method. The flocculant injection rate for the change in the amount of suspended solids contained in the stock solution is changed, the average analysis area of the floc is compared with the reference area, and when the average analysis area is larger than the reference area, the flocculant injection pump (9 ) When the average analysis area reaches the upper limit of the reference area, the current coagulant injection rate is maintained and the average analysis area is still larger than the reference area, and this operation is repeated. The flocculant injection control according to claim 1 or 2, wherein when the flocculant injection rate reaches a set lower limit value, an abnormal signal is output while maintaining the rotational speed of the flocculant injection pump (9). Method. The flocculant injection rate for the change in the amount of suspended solids in the stock solution is changed, the average analysis area of floc is compared with the reference area, and when the average analysis area is smaller than the reference area, the flocculant injection pump (9) When the number of rotations is increased and the average analysis area reaches within the lower limit of the reference area, the current coagulant injection rate is maintained and the average analysis area is smaller than the reference area. The agglomeration according to any one of claims 1 to 3, wherein when the agent injection rate reaches a set upper limit, an abnormal signal is output while maintaining the rotational speed of the agglutinating agent injection pump (9). Agent injection control method. When supplying a constant stock solution amount to the dehydrator (12), the average analysis area of the floc is compared with the reference area. If the average analysis area is larger than the reference area, the injection rate of the flocculant is decreased and the average analysis area is When the upper limit of the reference area is reached, the current coagulant injection rate is maintained, and when the coagulant injection rate reaches the set lower limit by repeating the above operation, the coagulant injection pump (9) 3. The flocculant injection control method according to claim 1, wherein an abnormal signal is output while maintaining the rotational speed. When supplying a certain amount of stock solution to the dehydrator (12), compare the average analysis area of the floc and the reference area, and if the average analysis area is smaller than the reference area, increase the rotation speed of the coagulant injection pump (9) When the average analysis area reaches within the lower limit of the reference area, the current coagulant injection rate is maintained, and when the coagulant injection rate reaches the set upper limit by repeating the above operation, the coagulant The flocculant injection control method according to any one of claims 1, 2, and 5, wherein an abnormal signal is output while maintaining the rotation speed of the injection pump (9). When the calculated average analysis area of flocs is larger than the reference area, the flocculant injection rate is decreased, and at the same time, the rotation speed of the stirrer (11) of the agglomeration mixing tank (5) is increased. When the flocculant injection rate and the rotation speed of the stirrer (11) are maintained, the above operation is repeated and the flocculant injection rate reaches the lower limit value set. The flocculant injection control method according to any one of claims 1, 2, 3, and 5, wherein an abnormal signal is output while maintaining the rotation speed of the agent injection pump (9) and the agitator (11). . When the calculated floc analysis area is smaller than the reference area, the flocculant injection rate is increased, and at the same time, the rotation speed of the stirrer (11) of the flocculent mixing tank (5) is decreased. When the lower limit value is reached, while maintaining the current coagulant injection rate and the rotation speed of the agitator (11), the above operation is repeated, and when the coagulant injection rate reaches the set lower limit value, The flocculant injection control method according to any one of claims 1, 2, 4, and 6, wherein an abnormal signal is output while maintaining the rotational speed of the agent injection pump (9) and the agitator (11). . The stock solution and the flocculant are supplied to a closed flocculent mixing tank (5) to form a floc of suspended solids contained in the stock solution, and the stock solution is dehydrated by the tank pressure of the flocculent mixing tank (5). In the stock solution supply apparatus to be supplied to the TV, a viewing window (14) is provided in the stock solution supply pipe (13) connected to the dehydrator (12), and the viewing window (14) captures the size of the floc of the suspended substance. (15) is provided, and an arithmetic unit (17) for binarizing the captured flock image and accumulating the average analysis area per floc is provided, and the average analysis area of the accumulated frock and a preset reference area are provided. And a coagulant proportional control (22) for transmitting a command signal based on the state of floc formation and a coagulant injection pump (9) for controlling the rotational speed based on the command signal. Injection Control device. The flocculant injection rate of the set value proportional to the fluctuation of the suspended solids contained in the stock solution is changed, and the average analysis area per floc of the stock solution supply pipe (13) is compared with the reference area, and the flocculant The number of revolutions of the infusion pump (9) is controlled, and an abnormal signal device (23) is provided in addition to the sequencer proportional control (22) to transmit an abnormal signal with the upper limit value and the lower limit value of the coagulant injection rate. The flocculant injection control device according to claim 9. When supplying a constant amount of stock solution to the dehydrator (12), the average analysis area of the floc of the stock solution supply pipe (13) is compared with the reference area, and the rotational speed of the flocculant injection pump (9) is controlled, The flocculant injection control device according to claim 9, wherein an abnormal signal device (23) is provided in addition to the sequencer proportional control (22), and an abnormal signal is transmitted at an upper limit value and a lower limit value of the flocculant injection rate. The average analysis area of the floc and the reference area are compared, and when the average analysis area is larger than the reference area, the rotation speed of the flocculant injection pump (9) is increased, and at the same time, the stirrer (11 ), And when the average analysis area of flocs is smaller than the reference area, the rotation speed of the flocculant injection pump (9) is decreased and at the same time the rotation speed of the agitator (11) is increased. The flocculant injection control device according to any one of claims 9 to 11, characterized in that

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