JPS63256108A - Method for controlling injection of flocculant - Google Patents

Abstract

PURPOSE:To exclude the visual observation and experience of a tester and to optimize the injection rate of a flocculant by preparing an injection control formula while renewing the optimum injection rate of the flocculant in accordance with a certain turbidity range of a suspension, and controlling the injection of the flocculant in conformity with the formula. CONSTITUTION:A suspension is sampled, the turbidity and its corresponding injection rate of the flocculant are detected, the optimum injection rate detected in accordance with the turbidity range to which the turbidity belongs is stored in place of the oldest stored value, an injection control formula is prepared by using the stored optimum injection rate and stored in place of the former injection control formula, the injection rate of the flocculant is calculated by the new control formula in accordance with thee detected turbidity, and the flocculant is injected in accordance with the result. By this method the visual observation and experience of a tester can be excluded, the injection control formula can be renewed in accordance with a certain turbidity range, and the injection rate of the flocculant can be optimized based on the latest detected result.

Description

Detailed Description of the Invention (1) Purpose of the Invention [Industrial Field of Application] The present invention relates to a method for controlling the injection of a flocculant, and in particular to a method for controlling the injection of a flocculant depending on a certain turbidity range of a suspension. This invention relates to a flocculant injection management method that optimizes the flocculant injection rate or injection amount by creating an injection management formula while updating each, and executing flocculant injection management using the injection management formula. .

[Prior art] Conventionally, the injection control method for this type of flocculant involves collecting an appropriate amount of a suspension of tap water, industrial water, sewage, industrial waste, etc., and distributing the same amount to multiple units. Then, the injection rate of the flocculant can be optimized by adding flocculant into the column at different injection rates, stirring and leaving it to stand, and then detecting the flocculation state through visual observation and experience of the tester. Management was proposed.

[Problems to be solved] However, in the conventional flocculant injection control method, the flocculant state was detected by visual observation and experience of the tester, so the detection result of the flocculant state may differ depending on the tester, and the flocculant injection may be different depending on the tester. There is a drawback that the rate cannot always be optimized, and it takes a lot of time to detect the state of agglomeration and ultimately determine the injection rate of the flocculant.

Therefore, in order to eliminate these drawbacks, the present invention creates an injection management formula while updating the appropriate injection rate of the flocculant according to a certain turbidity range of the suspension, and uses the injection management formula to adjust the flocculant injection rate. It is an object of the present invention to provide a flocculant injection management method that optimizes the flocculant injection rate or injection amount by executing the injection management.

(2) Structure of the Invention (c) Means for Solving Problems] Means for solving problems provided by the present invention are as follows: (a)
(b) a second step of detecting the turbidity of the suspension; (c) determining the appropriate injection rate of the flocculant for the collected suspension;
a third step of intermittently detecting turbidity in accordance with when turbidity is detected in the second step and at a frequency less than or equal to the frequency at which turbidity is detected in the second step; (d) a second step; (e) storing the appropriate injection rate detected in the third step in place of the oldest stored value in the turbidity range according to the turbidity range to which the detected turbidity belongs; (f) a fifth step of creating an injection management formula using the appropriate injection rate memorized in the step and storing it in place of the previous injection management formula; (g) a seventh step of injecting the flocculant into the suspension to be treated according to the injection rate calculated in the sixth step; A method for controlling injection of a flocculant, characterized by comprising the steps of:

[Function] The flocculant injection management method according to the present invention detects the turbidity of the suspension and the appropriate injection rate of the flocculant relative to the turbidity, and performs the detected appropriate injection according to the turbidity range to which the turbidity belongs. The rate is replaced with the oldest memorized value and stored, an injection control formula is created using the memorized appropriate injection rate, and the formula is memorized instead of the previous injection control formula, and the injection is performed according to the turbidity of the suspension. The injection rate of the flocculant is calculated using a control formula, and the flocculant is injected into the suspension to be treated according to the calculated injection rate.
It acts to eliminate the tester's visual observation and experience,
It also functions to prepare an injection control formula according to a certain turbidity range, and further functions to optimize the injection rate or amount of flocculant according to the latest detection results.

[Example] Next, the present invention will be specifically described with reference to the accompanying drawings.

FIG. 1 is a sectional view showing an actual suspension processing apparatus in which injection of a flocculant is controlled by an embodiment of the flocculant injection management method of the present invention.

FIG. 2 is a cross-sectional view showing an appropriate injection rate detection device that is included in the suspension processing apparatus of FIG. .

FIG. 3 is an operational explanatory diagram for explaining the operation of the appropriate injection rate detection device of FIG. 2, and shows temporal changes in the amount of received light I.

Figure 4 shows the diameter d of the aggregate obtained from the operation diagram in Figure 3.
, number n2 volume V and effective density ρ and flocculant injection rate WA
1 is a graph diagram showing the relationship between

Figure 5 shows the supernatant water turbidity τ obtained from the operation diagram in Figure 3.
, is a graph diagram showing the relationship between the settling velocity S and effective density ρ of the aggregate and the injection rate WA1 of the flocculant.

FIG. 6 is a sectional view showing an appropriate injection rate detection device in which four appropriate injection rate detection devices shown in FIG. 2 are arranged side by side.

FIGS. 7(a) to 7(c) are graphs showing the results of flocculant injection management performed in the suspension processing apparatus of FIG. 1 according to an embodiment of the present invention.

First, with reference to FIG. 1, an actual suspension processing apparatus in which injection of a flocculant is controlled by the flocculant injection management method of the present invention will be described.

Reference numeral 102 denotes a landing well, into which a suspension is supplied via a supply pipe 104 from an appropriate suspension supply source (not shown). 1.
06 is a coagulant mixing pond connected to the landing well 102 via a supply pipe 108, and is driven by a driving means such as an electric motor 1.
A stirring blade 110 that is rapidly rotated by a stirring blade 09 is also provided. Reference numeral 112 denotes an aggregate formation pond that is connected to the mixing pond 106 via a supply pipe 114, and has three areas 112A,
112G, each having a driving means such as an electric motor 115A.

~, stirring blade 116A rotated slowly by 115G
.

~116C are arranged. The mixed liquid of the flocculant and suspension formed in the mixing pond 106 and supplied to the flocculation basin 112 through the supply pipe 114 is first fed to the flocculant formation basin 1.
The stirring blade 11 in the first region 112^ of the 12
6A for a predetermined period of time, and then transferred to the second region 112B where it is slowly stirred for a predetermined period of time by stirring blades 116B.

Furthermore, the stirring blade 116G is transferred to the third region 112C.
The mixture is slowly stirred for a predetermined period of time. 118 is a sedimentation tank connected to the aggregate formation tank 112,! The mixed solution of the flocculant and the suspension in which the flocs are sufficiently formed, supplied from the third region 112C of the flocculation pond 112, is allowed to settle, and the flocs, or flocs, are settled and removed. are doing. A filtration tank 120 is connected to the outlet of the sedimentation tank 118 via a supply pipe 122, and after removing minute aggregates, that is, flocs that could not be removed by the sedimentation tank 118, the treated water is passed through the treated water pipe 12 as treated water.
4 to subsequent appropriate equipment.

Reference numeral 130 denotes a device for detecting the appropriate injection rate of the flocculant shown in FIG. 2 or FIG.
It is open to the mixing pond 106 and the like. 136 is a calculation device connected to the appropriate injection rate detection device 130;
32 or another turbidity meter 139 attached to the supply pipe 108. Depending on the size of.

Appropriate injection rate WA detected by the appropriate injection rate detection device 130
,” is selected. In other words, the arithmetic unit 13
6 is turbidity τ. is the predetermined value τ. When the turbidity is in a range smaller than l (i.e., a low turbidity range corresponding to the dry season or winter season), the turbidity τ. Fixed value τ. 82 (>τo11) (i.e., high turbidity range corresponding to the typhoon period)
and the turbidity τ. is the predetermined value τ. ■ and τ. (i.e., the intermediate turbidity range that occurs during normal periods)
The appropriate injection rate WA! ” in place of the oldest data in a different memory location, and set it as the latest data.The computing device 136 determines the appropriate injection rate for each of the low turbidity range, medium turbidity range, and high turbidity range. It holds an appropriate number (for example, 5) of data regarding WA, *.Arithmetic unit 1:16 holds an appropriate injection rate wA,
Each time the data is updated, an injection management formula % is created for calculating the flocculant injection rate WA+ using the data stored in each turbidity range (A and B are constants). The calculation device 13
6 indicates that the turbidity meter 138 or 13
The injection rate WAl of the flocculant is determined by the above formula according to the turbidity τ given by 9.

140 is a multiplier connected to the arithmetic unit 136 and the flow meter 142, and multiplies the injection rate WAl outputted by the arithmetic unit 136 and the flow rate detected by the flow meter 142, that is, the supply ff1Q to the mixing basin 106. By this, the injection amount of flocculant is calculated.

144 is a flocculant supply device connected to the multiplier 140;
Supply an amount of flocculant according to the injection amount calculated by the multiplier 140? 146 to the mixing basin 106 and injected into the suspension.

Then, the suspension is collected from the landing well 102 via the pump 134 and the supply pipe 132, and the appropriate injection rate detection device 130 according to the present invention calculates the appropriate injection rate wA,'' of the flocculant, as described below. .

The turbidity meter 138 attached to the supply pipe 132 or another turbidity meter 139 attached to the supply pipe 108 measures the turbidity τ of the suspension. has been measured to be relatively frequent.

Here, if desired, one of the turbidimeters 138 and 139 may be removed.

The appropriate injection rate wA,'' and the turbidity τ are both provided to the calculation device 136.The calculation device 136 calculates the turbidity τ.
. is the predetermined value τ. 11. τ. 2 and its turbidity τ.

It is determined which of the low turbidity range, medium turbidity range, and high turbidity range the turbidity belongs to. As a result of this judgment,
Turbidity τ. Within the low turbidity range, medium turbidity range, or high turbidity range where the
, "instead of the oldest data and updated to the latest data.Furthermore, the arithmetic unit 136 stores the updated turbidity range (for example, medium turbidity range) of the data in the memory containing the latest data. An injection management formula % formula % is created using the data and stored in place of the previous injection management formula.

The computing device gl 136 obtains the turbidity τ from the turbidity meter 138 or 139. Each time is input, the injection rate WA+ is calculated and output based on the injection management formula.

The injection rate WAI output from the arithmetic unit 136 is detected by a flow meter 142 in a 1 multiplier 140 .

It is multiplied by f& amount Q to obtain the injection amount R8 of the flocculant.

A flocculant is supplied from the flocculant supply device m144 to the mixing basin 106 according to the injection amount R'', and is injected into the suspension.

By intermittently repeating the two series of operations, the flocculant injection rate in the suspension processing device can be substantially adjusted to the appropriate injection rate.
A.'', which can shorten the processing time of the suspension and avoid unnecessary injection of flocculant.

To explain with more specific numerical values, the turbidity τ of the suspension
According to the advanced IT injection control method, the flocculant injection rate WAI is changed as shown in Figure 7(b) according to the change in the turbidity τ of the suspension. It has been managed more appropriately than the comparative example, and as a result, the turbidity τ of the treated water discharged from the sedimentation tank 118 can be improved compared to the comparative example as shown in FIG. 7(c).

Further, the configuration of the appropriate injection rate detection device 130 will be explained in detail with reference to FIGS. 2 to 6.

The IO is a batch-type stirring tank having an appropriate capacity, for example, a capacity of 1/2, and contains a mixed liquid 11 of a suspension and a flocculant. A stirring blade 12 is disposed in the stirring tank IO, and is appropriately attached to the free end of an output shaft 16 of a driving means, for example, an electric motor 14, arranged below the stirring tank 10.

18 is connected to an appropriate power source by the lead wire 19 (IJ not shown)
A light receiving device δ connected to the stirring tank 1o is arranged on the side surface of the stirring tank 1o, and receives light generated by an appropriate light source such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a light emitting diode, or a laser emitting means. For example, the mixed liquid 11 in the stirring tank 10 is transmitted as a parallel beam of light through a slit.
is supplied to.

20 is a phototransistor and a photodiode.

This is a light receiving device that includes an appropriate photoelectric conversion element such as CdS or COD as a light receiving means, and is disposed on the side of the stirring tank 1o. Since the light given by the light emitting device 18 receiving the light through the light receiving device 11 is scattered or blocked by the aggregates, that is, the flocs 17 in the mixed liquid II, the light receiving device 2o receives the scattered light or the attenuated transmitted light. is receiving light.

The light receiving device 20 is connected to the light receiving device 18 in order to receive the transmitted light.
The light emitting device 18 may be placed at a predetermined angle with respect to the parallel beam from the light emitting device 18 in order to receive scattered light. Two light receiving devices g! izo may be placed. In order to simplify the explanation, the light receiving device 20 will be described below as follows.
It is assumed that the light receiving device 18 is opposed to the light receiving device 18. In addition, in FIG. 2, only one set of the light receiving device 18 and the light receiving device 20 are arranged, but the present invention is not limited to this.
A plurality of sets of the light-emitting device 18 and the light-receiving device fi20 may be arranged.The light-emitting device 18 and the light-receiving device 20 may form an aggregate, that is, a flock 1, especially if they are arranged on the same horizontal plane.
It is convenient for measuring the sedimentation state of 7.

A measurement device 22 is connected to the light receiving device 20 via a lead wire 21, and measures the amount of light received by the light receiving device 2120 (hereinafter referred to as "received light amount"). In addition, the measuring device 22 determines the amount of received light I before the injection of the flocculant from the measured amount of received light I.
, (τ) and the fluctuation range of the received light amount I when flattened due to slow stirring by the stirring blade 12 (i.e., the predetermined value IL
and! , (difference between ,
) and the time T from when the slow stirring by the stirring blade 12 stops until the received light amount I becomes flat may be determined and output.

24 is a supply pipe whose one end is opened to the stirring tank 1o via an on-off valve 25, and the other end is connected to the supply pipe 132 (see Fig. 1), and 26 is a supply pipe whose one end is connected to the flocculant supply source 28. This is a flocculant supply pipe with one end communicating with the other, and the other end opening into the stirring tank IO via an on-off valve 27. 30 is a drain pipe, one end of which is opened at the bottom of the stirring tank IO, and the other end of which is connected to the on-off valve 3.
2 to the drainage pipe 133, and the stirring tank IO
Remove the detected mixed liquid 11 from (see Figure 1), 3
4 is a dark box with at least a stirring tank 10. It houses the light emitting device 18 and the light receiving device 2i20, and eliminates the influence of external light.

36 is the drive means 14, the measurement wave Hz, and the on-off valve 25.27
The peripheral speed ν of the stirring blade 12 is obtained from the driving means 14 by a calculation device connected to the driving means 14, and the fluctuation width ΔI and fluctuation period F of the received light amount Ii (τ) and the received light amount ■ are obtained from the measurement wave 2222. If desired, the amount of received light (Etc) and the time T are also given, and the supply amount M of the suspension liquid and the supply amount N of the flocculant from the on-off valves 25 and 27 are also given. The arithmetic unit 36 operates on aggregates or flocs 17.
The parameters for determining the agglomeration state of That is, the arithmetic unit 36 calculates the fluctuation range ΔI(
volt) and the constant α to calculate the aggregate or floc 1
Calculate the diameter d (c■) of 7 as d=α△I, and calculate the fluctuation period F (seconds) of the received light amount I and the stirring blade 1.
Using the circumferential speed ν (17 seconds) of 2 and the constant β, calculate the number n (1/c ff) of the aggregates or flocs 17, and then calculate the diameter d (cm) and the number n ( 1
/c■3) and the constant ε, calculate the aggregate, i.e., the body gI V (ckakuko) of the flonc 17, as ■=εd'3n, and find it from the received light NkI, (τ) (volts). Initial concentration W ~ (g/m) of suspended solids in the suspension and supply amount M
, the flocculant injection rate WA+ (mg/cross) obtained from N, the number n (1/cm') of flocs 17, the diameter d, the constant γ, and the coefficient a specific to the flocculant. The effective density ρ (g/c) of the flocs 17 is calculated, and if desired, the settling velocity S (c
/min), and using the amount of received light xr(τ) and constant λ, the supernatant water turbidity τ after the aggregates, that is, flocs 17, have settled.
(degrees) is calculated as τ;λIf(τ). Here, the relationship between the parameters calculated by the arithmetic unit 36 and the actual aggregation state of the aggregates, that is, the flocs 17, is the diameter d or an2 body diameter V.

Effective density ρ, sedimentation velocity S, supernatant water turbidity are closely related in this order, so if it is desired to accurately detect the flocculation state of flocs 17, the latter parameter may be used. Furthermore, if it is desired to detect the aggregation state more precisely, a combination of a plurality of parameters may be used.

38 is another arithmetic device connected to the arithmetic device 36, which calculates the aggregate, that is, the floc 1 calculated by the arithmetic device 36.
At least one of the diameter d of 7, the number n9 bodies gv, the effective density ρ, the settling speed S, and the supernatant water turbidity τ after the flocs 17 have settled, to the flocculant injection rate WAI at that time. The calculation unit 38 calculates the appropriate value WA," of the injection rate of the flocculant to the suspension at this time. In other words, the calculation device 38 calculates the appropriate value WA," The flocculant injection rate WAI (computing unit 36
(given by Corresponding to the beginning, the flocculant injection rate WAI is determined as the appropriate injection rate WAl'''.

In addition, with reference to FIGS. 2 to 5, the operation of the appropriate injection rate detection device 1 will be explained in detail.

After opening the on-off valve 32 and removing the mixed liquid 11 remaining in the stirring tank 10 through the drain pipe 30, the on-off valve 32 is closed.

The on-off valve 25 is opened for a predetermined time, and a predetermined amount M (for example, 1 liter) of the suspension is supplied into the stirring tank 10 from a suspension supply source (not shown) via the supply pipe 24.

When the supply of the suspension into the stirring tank 10 is completed, time t,
At this point, the stirring blade 12 begins to rotate rapidly, that is, at a high speed, by the driving means, for example, the electric motor 14.

Thereafter, by opening the on-off valve 27 for a predetermined time at time t2, a predetermined amount of flocculant is supplied to the flocculant supply source 2.
8 into the stirring tank 10 via the flocculant supply pipe 26. As the IJ collector, known flocculants such as polyaluminum chloride may be used as desired.

Prior to the start of rapid rotation of the stirring blade 12, the light emitting device 1
8. The light receiving device 20j5 and the measuring device 22 have been started, and the received light amount I of the transmitted light is measured through the suspension in the stirring tank lo.
, (τ) are measured and stored in the arithmetic unit 36.

The amount of received light I until time t2, that is, the time when the flocculant is supplied, is a constant value 1. (τ) When a predetermined amount N of flocculant is injected at time t2, the mixed liquid ll
Since aggregates, that is, flocs 17 are gradually formed within the stirring tank 10, and the mixed liquid 11 is rapidly stirred and moved within the stirring tank 10, the amount of light received by the light receiving device 20 increases slowly.

At time t3, when the stirring blade 12 starts to rotate at a slow speed, that is, at a low speed, aggregates or flocs 17 are further formed in the mixed liquid ll, and the diameter d thereof increases, and the mixed liquid ll'b<agitation. As the light is slowly stirred and moved in the tank 1O, the amount of light received by the light receiving device 20 does not increase or decrease little by little, but increases as a whole.

When time t4 is reached, the flocs 17 are sufficiently agglomerated in the mixed liquid 11 and their Ba does not change, and the mixed liquid 11 is being stirred and moved slowly in the stirring tank lo, so the light receiving device The amount of light received at 2120 becomes flat and reaches the predetermined value IL as the aggregates, that is, the flocs 17 pass through.
and I□.

Further, at time 1S, when the rotation of the stirring blade 12 is stopped to stop the stirring, the aggregates, that is, the flocs 17 formed in the mixed liquid 11 start to settle, so that the amount of light received by the light receiving device 2120 gradually decreases. While increasing and decreasing, time t6
After 0 time t6 when ir(τ) reaches a substantially constant value, the aggregates, that is, flocs 17 in the liquid mixture 11 no longer settle, so the amount of received light I maintains a constant value xrC).

For example, the amount of light received by the light receiving device 20 I when using a kaolin suspension containing 25 g of Risozon added to No. 12 Maki and injecting polyaluminum chloride at an injection rate of IS pupil g/l. When measured using the measuring device 22, the results were as shown in FIG.

Thereafter, the calculation device 36 calculates the diameter d, number n2 volume V, and effective density ρ of the flocs 17 as described above, and further calculates the settling velocity S and supernatant water turbidity τ if desired. . Using these parameters calculated by the calculation device 36, the aggregation state of the aggregates, that is, the flocs 17 can be detected as described above.

The diameter d, the number n1, the volume V, and the effective density ρ of the aggregate, that is, the floc 17, calculated by the calculation device 36.

The settling velocity S and the supernatant water turbidity τ are stored in the calculation unit 38 with respect to the flocculant population rate WAl.

The arithmetic unit 2238 calculates the diameter d of the aggregate, that is, the floc 17.
2 The injection rate W of the flocculant when the change in the volume V or the effective density p starts to become steep, or when the change in the number n, sedimentation rate S or supernatant water turbidity τ starts to become slow.
AI is determined as "appropriate injection rate wA," and output as desired.

I will explain the basis for this in more detail in January. That is, each time the above-mentioned measurements and calculations are repeated using, for example, a kaolin suspension prepared by adding 25 g of kaolin to 1 M fresh water, the diameter d of the aggregates or flocs 17, the number n1 bodies V, and the effective When the density ρ was calculated and plotted against the flocculant injection rate WAI, the result shown in FIG. 4 was obtained.

Similarly, using the kaolin suspension, each time the above-mentioned measurements and calculations are repeated, 1 aggregate or floc
When the effective density ρ, sedimentation rate S, and supernatant water turbidity τ of No. 7 were calculated and plotted against the flocculant injection rate wA□, FIG. 5 was obtained.

As is clear from FIGS. 4 and 5, as the flocculant injection rate WAI changes, the flocs 1
7 diameter d, number n2 volume V, effective density ρ and sedimentation velocity S
and supernatant water turbidity τ are changing. To be more specific, the injection rate wAI of the flocculant is the predetermined value WA1” (here] Omg
/See) If the number n of aggregates, i.e., flocs 17, does not change much, or the diameter dg and body size V become relatively large, the effective density ρ decreases, and unstable aggregates, i.e. It is determined that flocs 17 are formed. In addition, the injection rate WAl of the flocculant is its predetermined value WA
If it becomes more than ``I'', the sedimentation velocity S of the flocs 17 or the supernatant water turbidity τ after settling of the flocs 17 will not change much, and the flocculant injection rate WAI or its predetermined value WA will not change much. However, as the injection amount of 2S collector increases, the aggregates, i.e., flocs 1
It can be judged that the amount of coagulated precipitate in No. 7 cannot be increased, which is not preferable.

On the other hand, the flocculant injection rate WAI is the predetermined value wAl”
, the aggregate or floc 1
The number n of 7 has become extremely large, its diameter d and volume 2 have also become extremely small, and the effective density ρ has increased, so it can be concluded that relatively stable aggregates, that is, flocs 17, have been formed. Ru.

However, in this case, the aggregates or flocs 17
The sedimentation velocity S of is small, and the supernatant water turbidity τ after sedimentation of flocs 17 is large, and therefore! 2 If the flocculant injection rate WAI or its predetermined value WA becomes significantly smaller than the flocculant injection rate WAI, it is judged that the flocculent, that is, the flocs 17, cannot be efficiently precipitated and removed even if the amount of flocculant injection can be reduced. , undesirable.

Therefore, if the predetermined value wA,'' at this time is the injection rate of the flocculant, the amount of flocculant injection can be reduced and the amount of flocculation and sedimentation of suspended matter in the suspension can be maintained at a relatively large value. Therefore, floating matter in the !J suspension can be efficiently coagulated and precipitated and removed.

For this reason, the arithmetic unit 38 determines wA,' to be the appropriate injection rate of the flocculant, as described above.

As described above, in the present invention, the injection rate of the flocculant into the suspension is controlled to be an appropriate injection rate.

In the above, we have explained the appropriate injection rate detection device 21130 that includes only one stirring tank IO (see Figs. 2 to 5), but since this requires a large amount of time to detect the agglomeration state, Multiple (here, four) as shown in Figure 6.
Two stirring tanks may be placed side by side.

The proper injection rate detection device 130 of FIG. Except that the flocculant supply source 28 and the computing device fi 38 are shared.

The structure and operation are similar to that of the appropriate injection rate detection device 130 shown in FIG.
Since the components are substantially the same as each other, the same reference numerals as those given to the appropriate injection rate detection device 130 in FIG. 2 are given to each member, and detailed explanation thereof will be omitted. Reference numbers include A, B, C,
A D sign has been added. Open/close valves 27A, ~, 27D
are open for different times, and the stirring tank 10
The injection rate of the flocculant to the mixed liquids 11^, -, 11D in A, -, ① oD is checked.

In addition, in the above description, only the case where the appropriate injection rate of flocculant is detected less frequently by the appropriate injection rate detection device 211:10 than the frequency of turbidity detection by the turbidimeters 138 and 139 has been described, but the present invention is not limited to this case, and if desired, a turbidity meter 138, 1:19
Frequency of turbidity detection and appropriate injection rate detection device 21t:to
The frequency of detection of the appropriate injection rate of the flocculant may be set to be the same as the frequency of detection of the appropriate injection rate of the flocculant.

[Effects of the Invention] As is clear from the above, the flocculant injection management method according to the present invention includes (a) a first step of collecting a suspension, and (b) detecting the turbidity of the suspension. (c) determining the appropriate injection rate of the flocculant for the collected suspension;
a third step of intermittently detecting turbidity depending on when turbidity is detected in the second step and at a frequency less than the frequency at which turbidity is detected in the second step; (cl) in the second step; a fourth step of storing the appropriate injection rate detected in the third step in place of the oldest stored value in the turbidity range according to the turbidity range to which the detected turbidity belongs; (e) a fourth step; A fifth step (f) of creating an injection management formula using the appropriate injection rate stored in the step and storing it in place of the previous injection management formula. (g) a seventh step of injecting the flocculant into the suspension to be treated according to the injection rate calculated in the sixth step; (i) It has the effect of eliminating the U-view observation and experience of the tester, and (ii) It has the effect of updating the injection control formula depending on a certain turbidity range. Furthermore, (iii) there is an effect that the injection rate or injection amount of the coagulant can be optimized according to the latest detection results.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an actual suspension processing apparatus in which the injection of a flocculant is controlled by an embodiment of the flocculant injection management method of the present invention, and FIG. A cross-sectional view showing the appropriate injection rate detection bag included in the processing bag and used to detect the appropriate injection rate of the flocculant in order to carry out an embodiment of the present invention. An operation explanatory diagram for explaining the operation of the detection device, FIG. 4 shows the relationship between the diameter d, number n1 volume V, and effective density ρ of the aggregate obtained from the operation explanatory diagram in FIG. 3 and the flocculant injection rate WAI. Figure 5 is a graph showing the relationship between the supernatant water turbidity determined from the operation diagram in Figure 3, and the sedimentation rate S and effective density ρ of the flocculent and the injection rate W of the flocculant.
Graph showing the relationship between FIG. 2 is a graph diagram showing the result of executing flocculant injection management according to an embodiment of the present invention in the suspension processing apparatus of FIG. 1. FIG. 102・・・・・・・・・・・・・・・・・・・Waterfall well 1
06・・・・・・・・−・・・・・・・・・Mixing pond 11
2・・・・・・・・・・・・・・・ Aggregate formation pond 118・・・・・・・・・・・・・・・・・・Settlement basin 1
20・・・・・・・・・・・・・・・Filtration pond 13
0-・・・・・・・・・・Appropriate injection rate detection device 136 −・・・・・−・−・・・・Computation device 1”l, 13 'l・・・・・・・・・−・・・・・・・−
Turbidity meter 140・・・・・・・・・・・・・・・ Multiplier 142・・・・・・・・・−・・・・・・・・・Flow meter 144...・・・・・・・・・・・・・・・Flocculant supply device 10・・・・・・・・・・・・・・・・・・
- Stirring tank 11・・・・・・・・・・・・・・・・・・
-Mixed liquid 12・・・・・・・・・・・・・・・・・・
・Agitating blade 14・−・・・・・・・・・・・・・・・・・・・
・・WIA operation means 16・・・・・・・・・・・・・・・
・・・・・・Output shaft 18・・・・・・・・・・・・・・・・・・
.....Light emitting device 20.....
......Light receiving device 22...
......-Measuring device 24...
−・・・・− Supply pipe 25.27・・・・・・・・・
・・・・・・Opening/closing valve 25・・・・・・・・・
...Flocculant supply pipe 28...
......Flocculant supply source 30...
・・・・・・・・・Building pipe 32・・・・・・・・・・・・
......Opening/closing valve 34...
・・・・・・・・・Dark box 36.38・・・・・・・・・
・・・・・・Patent applicant for computing device Ebara Infilco Co., Ltd. Ebara Research Institute Co., Ltd. Representative Patent attorney Takao Satoh, engineer Page 1 [F] Inventor Mitsuguchi Imai Inventor Nakajima
Mutsuo @ Inventor Chiaki Igarashi 1-6-27 Konan, Minato-ku, Tokyo Inside Ebara Infilco Corporation 1-6-27 Konan, Minato-ku, Tokyo Inside Ebara Infilco Corporation

Claims (13)

[Claims] (1) (a) First step of collecting the suspension; (b) Second step of detecting the turbidity of the suspension; (c) Proper injection of flocculant into the collected suspension. rate,
(d) in the second step, detecting the turbidity intermittently depending on when the turbidity is detected in the second step and at a frequency less than or equal to the frequency at which the turbidity is detected in the second step; a fourth step of storing the appropriate injection rate detected in the third step in place of the oldest stored value in the turbidity range according to the turbidity range to which the detected turbidity belongs; (c) a fourth step; The fifth step is to create an injection management formula using the appropriate injection rate stored in the process and store it in place of the previous injection management formula.
(f) a sixth step of calculating the injection rate of the flocculant according to the injection control formula according to the turbidity detected in the second step; (g) injection calculated in the sixth step; and a seventh step of injecting the flocculant into the suspension to be treated according to the rate. (2) The third step includes (a) a first partial step of stirring the collected suspension, and (b) a second partial step of injecting a flocculant into the suspension being stirred. , (c) a third partial step of stirring the mixture of suspension and flocculant after the injection of the flocculant at a lower stirring speed than in the first partial step; and (d) at least a third partial step. a fourth partial step of measuring the amount of light received from the light emitting device to the light receiving device via the mixed liquid during the partial step; (e) aggregation of the mixed liquid based on the amount of received light measured in the fourth partial step; (f) a sixth partial step of determining an appropriate injection rate of the flocculant according to the agglomeration state detected in the fifth partial step; Claim No. (1)
Method for controlling the injection of flocculant described in Section 1. (3) (i) In the fifth partial step, the aggregation state of the mixed liquid is detected by calculating the number of aggregates from the fluctuation period when the amount of received light becomes flat and the stirring speed in the third partial step. and (ii) in the sixth partial step, the injection rate of the flocculant corresponding to when the change in the number of aggregates starts to slow down is determined as the appropriate injection rate. The method for managing injection of a flocculant according to item (2). (4) (i) In the fifth sub-step, the aggregation state of the mixed liquid is detected by calculating the diameter of the aggregate from the fluctuation range when the amount of received light is flattened, and (ii) in the sixth sub-step Claim (2) or (3) characterized in that, in the partial step, the injection rate of the flocculant corresponding to when the change in the diameter of the aggregate starts to become steep is determined as the appropriate injection rate. ) Method for controlling the injection of flocculant described in section 2. (5) (i) In the fifth partial step, calculate the number of aggregates from the fluctuation period when the amount of received light is flattened and the stirring speed in the third partial step, and calculate the number of aggregates when the amount of received light is flattened. By calculating the diameter of the aggregate from the fluctuation width and calculating the volume of the aggregate from the number and diameter of the aggregate, the agglomeration state of the mixed liquid is detected, and (ii) in the sixth partial step, Claim 2, characterized in that the injection rate of the flocculant corresponding to when the change in the number of aggregates starts to slow down and the change in diameter and volume starts to become steep is determined as the appropriate injection rate. ) Method for controlling the injection of flocculant described in section 2. (6) (i) In the fifth partial step, calculate the number of aggregates from the fluctuation period when the amount of received light becomes flat and the stirring speed in the third partial step, and calculate the number of aggregates when the amount of received light becomes flat. By calculating the diameter of the aggregates from the fluctuation range, and calculating the effective density of the aggregates from the number and diameter of the aggregates, the suspended solids concentration of the suspension, and the injection rate of the flocculant, the flocculation of the mixed liquid is performed. (ii) In the sixth partial step, the injection rate of the flocculant corresponding to when the change in the number of aggregates starts to slow down and the change in diameter and effective density starts to become steep is determined as an appropriate injection rate. A method for managing injection of a flocculant according to claim (2), characterized in that the method comprises determining: (7) The third step includes (a) a first partial step of stirring the collected suspension, and (b) a second partial step of injecting a flocculant into the suspension being stirred. , (c) a third partial step of stirring the mixture of suspension and flocculant after the injection of the flocculant at a lower stirring speed than in the first partial step; and (d) at least a third partial step. a fourth partial step of measuring the amount of received light given from the light emitting device to the light receiving device via the mixed liquid during the partial step; (e) after the amount of received light measured in the fourth partial step is flattened; a fifth partial step of stopping stirring of the liquid mixture; (f) a sixth partial step of measuring the amount of light received by the light-emitting device through the liquid mixture in the fifth partial step;
(g) a seventh partial step of detecting the agglomeration state of the liquid mixture from the amount of received light measured in the fourth partial step and the sixth partial step; (h) the seventh partial step and an eighth partial step of determining an appropriate injection rate of the flocculant according to the agglomeration state detected in the claim (1).
Method for controlling the injection of flocculant described in Section 1. (8) (i) In the seventh partial step, by calculating the supernatant water turbidity after the aggregates have been precipitated from the amount of light received when the amount of received light measured in the sixth partial step is flattened. , detecting the flocculating state of the liquid mixture, and (ii) determining the injection rate of the flocculant corresponding to when the change in supernatant water turbidity starts to slow down as the appropriate injection rate in the eighth partial step; A flocculant injection management method according to claim (7), characterized in that: (9) (i) In the seventh partial step, calculate the sedimentation rate of the aggregate from the time from the time when stirring is stopped in the fifth partial step until the amount of received light measured in the sixth partial step becomes flat. By doing so, the flocculation state of the liquid mixture is detected, and (ii) in the eighth partial step, the injection rate of the flocculant corresponding to when the change in the sedimentation rate of the aggregates starts to become slow is determined as the appropriate injection rate. A method for managing injection of a flocculant according to claim (7), characterized in that: (10) (i) In the seventh partial step, calculate the number of aggregates from the fluctuation period when the amount of received light measured in the fourth partial step is flattened and the stirring speed in the third partial step. (ii) in the eighth partial step, the injection rate of the flocculant corresponding to when the change in the number of aggregates starts to become slow is determined as the appropriate injection rate. A flocculant injection management method according to any one of claims (7) to (9). (11) (i) In the seventh partial step, the aggregation state of the mixed liquid is detected by calculating the diameter of the aggregate from the fluctuation width when the amount of received light measured in the fourth partial step becomes flat. and (ii) in the eighth partial step, the injection rate of the flocculant corresponding to when the change in the diameter of the aggregate starts to become steep is determined as the appropriate injection rate. The method for managing injection of a flocculant according to any one of items (7) to (10). (12) (i) In the seventh partial step, calculate the number of aggregates from the fluctuation period when the amount of received light measured in the fourth partial step is flattened and the stirring speed in the third partial step, Then, the diameter of the aggregate is calculated from the variation width when the amount of received light measured in the fourth partial step is flattened, and the volume of the aggregate is calculated from the number and diameter of the aggregate, thereby performing mixing. Detecting the flocculating state of the liquid, and (ii) adjusting the injection rate of the flocculant appropriately when the change in the number of aggregates starts to slow down and the change in diameter and volume starts to steepen in the eighth partial step. A method for controlling injection of a flocculant according to claim (7), characterized in that the injection rate is determined. (13) (i) In the seventh partial step, calculate the number of aggregates from the fluctuation period when the amount of received light measured in the fourth partial step is flattened and the stirring speed in the third partial step, Then, calculate the diameter of the aggregate from the fluctuation range when the amount of received light measured in the fourth partial step is flattened, and calculate the number and diameter of the aggregate, the suspended matter concentration of the suspension, and the injection of the flocculant. (ii) In the eighth partial step, the change in the number of aggregates begins to slow and the diameter and effective density of the aggregates are detected. The flocculant injection management method according to claim (7), characterized in that the flocculant injection rate corresponding to when the change starts to become steep is determined as the appropriate injection rate.