JPS61111111A - Flocculation controller - Google Patents

Abstract

PURPOSE:To flocculate stably at all times by measuring the brightness level of a floc, discriminating the quality of the formed floc, and operating appropri ately the amt. of a flocculant to be injected and the agitating power of a flocculator on the basis of said discrimination. CONSTITUTION:A camera device 100 for transducing the brightness signal of the image of floc 34 into an electric signal is arranged in a flocculation pond 30. The picture processing of the image of the floc 34 is carried out by a picture processing device 110 on the basis of said electric signal, and the characteristic values of the brightness level distribution of the floc are calculated. Besides, the amt. A of a flocculant to be injected by a flocculant injector 22 is calculated in a flocculant injection controller 200 by receiving the signal of said characteris tic values of the brightness level distribution of the floc. The injection of the flocculant is operated by the flocculant injector 22 in correspondence with the signal A. Meanwhile, each number of revolutions of agitating motors 32A, 32B, and 32C is controlled by an agitation controller 300 receiving the signal of said characteristic value of the brightness level distribution of the flocs.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a control device for floc formation in a floc formation pond (mixing pond) of a water purification plant.

[Background of the Invention In water purification plants, turbid substances in raw water are flocculated to form flocs, and these flocs are allowed to settle. For this reason, it is essential to monitor flocs in the floc formation pond (mixing pond).

Conventionally, flocs were monitored visually several times a day by water treatment plant maintenance managers. Because it relies on visual inspection, even if it is possible to qualitatively determine the size of flocs, it is not possible to accurately determine the quality of floc formation.

On the other hand, recently, industrial television cameras (ITVs) have been used to monitor flocs in floc formation ponds.
As described in Japanese Patent Application No. 143296, a method for identifying flocs by binarizing flocs and water using a photoelectric conversion device has also been devised. When determining the particle size of the flocs from the binarized flocs to determine the quality of floc formation, the floc particle size is used as a basis for determining the quality of the floc formation. but,
Even if the floc has a large particle size, it is not optimal if the floc density is low. This is because flocs with low density settle at a slow rate in the sedimentation basin, and in addition, the micro flocs that make up the flocs are left behind during the sedimentation process. This is because it flows into the suitable area and becomes a load, causing the excessively suitable area to be blocked.

As described above, there is a drawback that it is not possible to form flocs optimally just by knowing the particle size of the flocs.

[Object of the Invention] An object of the present invention is to provide a floc formation control device that can stably form flocs with good sedimentation properties in a floc formation pond (mixing pond) of a water purification plant.

[Summary of the Invention] When flocs have a high density and a large particle size, they have good sedimentation properties.Although a method for recognizing flocs by binarizing flocs is known, the idea of focusing on the brightness level of flocs is There wasn't one before.

The present invention measures the luminance level of flocs using image processing technology and controls the floc formation process based on this measured value to form optimal flocs. That is, there is a close relationship between floc formation and the luminance level distribution of flocs, and this is used to control floc formation.

[Embodiment of the Invention] An embodiment of the present invention is shown in FIG. 1. In FIG. 1, raw water taken from a river etc. passes through a settling basin (not shown) and reaches the landing well 10. Coarse particles are sedimented and removed. The fine particles do not settle in the landing well 10, and the raw water containing these fine particles is led to the rapid mixing basin 20. Rapid mixing pond 20
A stirrer 21 is provided. In addition, rapid mixing pond 2
A flocculant is injected from the flocculant injector 22 into 0. In the rapid mixing pond 20, suspended fine particles become micro flocs by the action of a flocculant. The flocculation pond 30 is provided with three stirring paddles 31A, 31B, and 31C, and these stirring paddles 31A, 31B, and 31C are rotationally driven by stirring motors 32A, 32B, and 32G, respectively. Between the stirring paddles 31A, 31B, and 31G is a rectifying wall 33A.

It is separated by 33B. The micro flocs that have flowed into the flocculation pond 3o from the rapid mixing basin 20 flow down in the flocculation basin 30 one after another, stirring paddles 31A, 31B,
The mixture is sequentially stirred by 31G. While the minute flocs sequentially flow down the floc formation pond 30, the flocs collide and coalesce with each other, forming a large floc 34. In this manner, the particle size of the flocs gradually increases while passing through the floc formation pond 30.

Inside the floc formation pond 30 is an imaging bag that converts the luminance signal of the image of the floc 34 into an electrical signal! ! Zo.

The image processing device 110 processes images of the flock 34 based on electrical signals obtained by the imaging device 100. conduct.

Calculate the characteristic value of the brightness level distribution.

The flocculant injection control bag [200 receives the signal of the characteristic value of the floc brightness level distribution calculated by the image processing device 110 and calculates the flocculant injection amount A of the flocculant injection machine 22. The flocculant injection amount of the flocculant injector 22 is controlled according to the signal A.

On the other hand, it is made by the stirring control department! ! ! 300 is an image processing bag fl! 11
In response to the signal of the characteristic value of the floc luminance level distribution calculated at 0, the rotation speeds Nr(A), Nr(B), and Nr(C) of the stirring motors 32A, 32B, and 32C are controlled. The rotational speed Nr of the stirring motors 32A, 32B, and 32G may be the same or different. This is determined by the water treatment plant.

When the rotation speeds Nr of the stirring motors 32A, 32B, and 32C are different, the motor speed on the upstream side is higher than that on the downstream side.

Stirring paddles 31A, 31B are provided by stirring motors 32A, 32B, 32C, respectively.

31C is driven at the rotational speed.

The flocs 34 formed in the floc formation basin 30 flow into the settling basin 40 and are settled and removed. The supernatant water from which the flocs 34 have been removed flows into the filter basin 50. In the vi oversuitable area 0, the remaining minute flocs that were not removed in the settling tank 4o are filtered and removed. The water that has passed through the vI battery 50 is supplied to consumers through a drainage pond (not shown), a reservoir (not shown), and the like.

FIG. 2 shows a detailed diagram of an example of the imaging device 100 and the image processing device 110.

The ITV 130 fixed in the airtight container 120 is exposed to a lens 111 made of transparent material such as glass using a close-up lens 131.
The image of the flocs 34 in the floc formation pond 30 is enlarged and recognized through the 16 window 121.

Wiper 1 driven by wiper driving bag [123
22 is ll! I! Observation window 121 and back screen 1
24 It is designed to operate periodically to remove dirt from the surface. The pack screen 124 is provided to accurately recognize flock groups with high contrast, and is installed in front of the observation window 121 by back screen fixtures 124A and 124B fixed to the airtight volume 120.

The back screen 124 is preferably a dark color in order to accurately recognize white flocks with high contrast, and the light-shielding cover 142 darkens the area around where the ITv 130 is placed to keep the illuminance from only the lamp 140 under a certain condition. It is set up for the purpose of By providing the light-shielding cover 142, the image of the flock group will not be affected by changes in surrounding illuminance.

A plurality of lamps 140 are installed, and irradiate the flocks 34 from many sides. In addition, in FIG. 2, an illuminance controller 141 is provided to keep the illuminance constant even without providing the light shielding cover 142, and the illuminance is controlled to be constant at appropriate times according to changes in the surrounding illuminance. lamp 14
In order to accurately recognize flocs regardless of their movement, an instantaneous light-emitting stroboscope or the like may be used. Baffle board 125A, 125B
, 125G in the floc formation pond 30.

It is installed to suppress the movement of water as much as possible and not to block the lighting. Therefore, an image of a group of flocs in a flowing state can be recognized with high accuracy.

The brightness information of the flock image captured by ITV130 is provided by IT.
Image recognition function via V controller 132
Device! ! 150. The ITV controller 132 also has a function of giving a timing signal to the ITV 130 to determine the timing to take out luminance information.0 The image recognition control device t160 is an image recognition device! The number of times of flock recognition by 150 is controlled.

Monitoring of the floc formation status using these devices is carried out once every 10 minutes to 1 hour, since it rarely changes rapidly in a short period of time.

Next, the image information of the flock group is sent to the image recognition device 11150.
The operation performed by signal processing will be explained below.

Figure 3 is a schematic diagram of flocs when the floc formation is good, the fourth column shows the distribution of the brightness level of one floc at this time, and Figure 5 is a schematic diagram of the flocs when the floc formation is poor. FIG. 6 shows the distribution of the luminance level of one flock at this time. When floc formation is good in this way, compact, high-density flocs (with good sedimentation properties) are formed, and the boundary between flocs and water is clear. On the other hand, when a large amount of flocculant is injected, the boundary between floc and water is unclear.

The flock group is white, so the brightness level is high.

On the other hand, since the background puck screen 124 is black, the brightness level of the water is low.The brightness level is displayed in 256 levels, for example, where the brightness is low at the top of the vertical axis and high at the bottom.Since the flock 34 is white, The luminance level of the flock becomes higher. Namely.

The portion where the luminance level becomes a valley in the downward direction represents the floc.

In a state of high density and good floc formation, the boundary between the floc and water is clear, so the brightness level changes rapidly at this boundary. On the other hand, when flocs with low density are formed due to inappropriate coagulant injection, the boundary between the flocs and water is unclear, so the brightness level changes gradually at this boundary. In this way, it is possible to determine whether the floc formation is good or not based on the distribution of the luminance level of the flocs.

FIG. 7 is a histogram of brightness levels where the horizontal axis is the brightness level and the vertical axis is the number of pixels. Since the method of obtaining the histogram is well known as a publicly known technique, detailed explanation will be omitted. In FIG. 7, (a) shows the case where floc formation is good. That is, as shown in FIG. 4, the brightness level of the floc part and the brightness level of the water part are clear, so The level distribution becomes a sharp peak.

On the other hand, (b) in Figure 7 shows a case where floc formation is poor (amount of coagulant injected is large), that is, as shown in Figure 6, the brightness level of the floc part and the brightness level of the water part are different. is unclear, so the distribution of brightness levels in FIG. 7 forms a gentle peak. In other words, it is good if the brightness level distribution is sharp and bright (from the right side), and conversely, it is bad if the distribution is gentle and dark (from the left side).

The flocculant injection control device 200 is an image recognition device in the image processing device 110! The moment of the histogram distribution is used as the 0 judgment N criterion for making this judgment using the histogram signal N(I) (I is the luminance level/L/) obtained from the 150. The zero-order moment M6 (area), the first-order moment Mz (average), and the second-order moment Mx (standard deviation) can be expressed by the following equations.

In this example, the brightness levels range from 1 to 256.

Coagulant injection control device! 200 calculates the flocculant injection amount A in consideration of these M, , M, and M2. That is, the calculation formula is determined by the following formula.

A=fa(M,,Ml,M,) ・−・−・・(4
) Here, fa is a function that determines the flocculant injection amount A by Mal Ml and M, and the influence of 1M0 and M is small, but
When M2 is large, the coagulant injection amount A is decreased, and conversely M
When 2 is small, the function increases the flocculant injection amount A. In this way, the flocculant injection control device! 20
0 determines the flocculant injection amount A and operates the flocculant injection machine 22.

The stirring control device [300 is a histogram signal N(1) obtained from the image recognition bag Wt15o in the image processing group W1110.
) (I is the brightness level) using a stirring motor 32A,
Manipulate the rotation speed of 32B and 32G.

The function for calculating the rotation speed Nr is as follows.

Nr=fn(Ma2M, Mi) ” ” ' (
5) Here, fn is a function that determines the rotation speed Nr by M, ML and M. Here, the influence of M4 and Ml is small, but the influence of M is large. In other words, since Mo is the total projected area of the floc, when Mo is small, it means that only small flocs are formed.
@t 1(1) 't' * t? ! 12' *
t t 6 : k I=Ct Z , t l b
1゜1 In this case, reduce the rotation speed Nr.On the other hand, when Mo is large, it means that the flocs are growing too much, so the stirring is too weak.In other words, in this case, increase the rotation speed Nr. let

In this way, when Mo is small, the rotational speed Nr is decreased, and when Mo is large, the rotational speed Nr is increased.

The stirring control device 300 calculates the rotational speed Nr of the stirring motors 32A, 32B, and 32C according to equation (5) and controls the stirring force of the floc formation pond 30 by operating the stirring paddles 31A, 31B, and 31G.

[Effects of the Invention] According to the present invention, the quality of floc formation is determined by measuring the luminance level of the flocs, and based on this, the amount of flocculant injected and the stirring force of the flocculator are appropriately controlled, so that the flocculator is always stable. For example, the flocculant injection amount and stirring force can be adjusted to suit the floc density and sedimentation properties by determining the floc density and sedimentation properties, thereby ensuring good floc formation at all times. As a result, the load on the sedimentation basin and filtration basin can be kept low.
1 energy, labor saving, and improved reliability.

[Brief explanation of the drawing]

1 and 2 are configuration diagrams showing one embodiment of the present invention, and FIG.
7 to 7 are diagrams for explaining the present invention in detail. [Brief explanation of symbols] ′ 1o...Water landing well, 20...Rapid mixing pond, 22...
Flocculant injection machine, 30... floc formation pond, 31A. 31B, 31G... Stirring paddle, 32A, 32B,
32G... Stirring motor, 100... Imaging device, 1
10...Image processing device, 2oO...Flocculant injection control 2 eyes lσθ //θ /24B 3 eyes %5 4 solids Figure 4 7 eyes Continuing from page 1) Inventor: Mori Shun 2 Hitachi University, Mika-cho 5-chome or 2-1 Factory Hitachi, Ltd. Omi 2-1 Hitachi, Ltd. Omi Procedures Amendment (Method) 1985't-March 2 1, 'j Display of the case of Gakudon Shiga, Commissioner of the License Agency, 1982 Patent Application No. 231752 Name of the invention Flock formation control device Agent

Claims (1)

[Claims] 1. A flocculation pond having a flocculant injection means and a stirring means, an imaging means for converting luminance information of an image of a group of flocs in the flocculation pond into an electrical signal, and an electric signal obtained from the imaging means. an image processing means that performs image processing of the floc group and calculates the distribution characteristics of the floc group; and an image processing means that performs image processing of the floc group and calculates the distribution characteristics of the floc group; A floc formation control device equipped with an operating means for operating