JPS63278509A - Method for controlling agitation of flocculation basin - Google Patents

Abstract

PURPOSE:To reduce the necessary controlling time while excluding visual observation and experience by controlling the agitation of a flocculation basin based on the flocculating time obtained from the quantity of transmitted light at the time of injecting a flocculant into a sampled suspension at a specified injection rate and the agitating velocity gradient. CONSTITUTION:A flocculant is injected into a suspension being rapidly agitated in a mixing basin 106, and the slow and rapid agitation in the succeeding flocculation basin 112 is controlled by the following method. Namely, a flocculant is firstly injected into the suspension sampled on the upstream side of the mixing basin, the suspension is agitated in an agitated vessel at a low velocity, the quantity of the light received from a light emitting device through the suspension is measured to obtain the flocculating time, and the velocity gradient of agitation is simultaneously obtained. The agitation of the flocculation basin is controlled based on the flocculating time, velocity gradient, amt. of the suspension flowing into the mixing basin 106, and volume of the flocculation basin 112. By this method, visual observation and experience can be excluded, and the time necessary for the control of agitation can be reduced.

Description

Detailed Description of the Invention (1) Purpose of the Invention [Field of Industrial Application] The present invention relates to a stirring control method for a flocculate formation pond, and in particular, the present invention relates to a method for controlling agitation in a flocculation pond, and in particular, the present invention relates to a method for controlling agitation in a flocculation pond, and in particular, a flocculant is injected into a collected suspension while stirring. The agitation control in the flocculation pond is performed by detecting the velocity gradient and flocculation time at which the mixing basin is applied, and by detecting the amount of suspension supplied to the mixing basin and the capacity of the flocculation basin. The present invention relates to a stirring control method for an aggregate formation pond.

[Prior Art] Conventionally, as a stirring control method for this type of aggregate formation pond, a flocculant is injected into a mixing pond which performs rapid stirring, and then aggregates are formed in an aggregate formation pond which performs slow stirring. Suspensions of clean water, industrial water, sewage, industrial waste liquid, etc. are actually sampled using a beaker, and the condition of aggregate formation is determined based on visual observation and experience of the tester. It has been proposed to adjust the agitation control in the formation basin.

[Problems to be solved] However, in the conventional agitation control method for aggregate formation ponds,
Since the agitation process in the aggregate formation pond was judged based on visual observation and experience of the tester, there was a drawback that the judgment results differed depending on the tester and it was not possible to optimize the agitation process in the aggregate formation basin. Since it takes more than 30 minutes for the formation of aggregates in the pond, it takes a lot of time to judge the state of aggregate formation, and there is a drawback that it is not possible to respond immediately to changes in the suspension. The agitation control cannot be performed with high precision, and especially when the agglomerate formation pond is divided into a plurality of regions, there is also the disadvantage that once formed agglomerates are destroyed by agitation in subsequent regions.

Therefore, in order to eliminate these drawbacks, the present invention calculates the aggregate formation time and velocity gradient when a flocculant is injected into the collected suspension at a predetermined injection rate, and adjusts the aggregate formation pond accordingly. It is an object of the present invention to provide a method for controlling agitation of an aggregate formation pond by controlling agitation.

(2) Structure of the invention [Means for solving problems] A first solution to the problem provided by the present invention is as follows.

[In a stirring control method for an aggregate formation pond, in which a flocculant is injected into a suspension while being rapidly stirred in a mixing basin, and then aggregates are formed by slow stirring in an aggregate formation basin.

(a) A first step of injecting a flocculant into the suspension collected upstream of the mixing pond and stirring it in a stirring tank.

(b) Lowered power than in the first step , condensation in the first step at a stirring speed of Stir the suspension containing the concentrate and the second step.

(c) Speed of stirring in the second step The third step is to find the gradient.

(d) At least during the second step.

In the first step, flocculant is injected. from the light-emitting device through the suspension. Amount of light received by the light receiving device and a fourth step of measuring.

(e) Received light measured in the fourth step Pour the flocculant in the first step based on the amount When aggregates form in the suspension A fifth step of determining the time, (“) supply of suspension to the mixing pond; and a sixth step of detecting the feed amount.

(g) The velocity gradient obtained in the third step, the aggregate formation time obtained in the fifth step, the supply amount of suspension detected in the sixth step, and the volume of the aggregate-forming foam. and a seventh step of controlling the agitation in the agglomerate-forming foam using the agitation control method for an agglomerate-forming pond."

The second solution to the problem provided by the present invention is as follows.

"In an agitation control method for an aggregate formation pond, in which a flocculant is injected into a suspension with rapid stirring in a mixing basin, and then aggregates are formed by slow stirring in an aggregate formation basin.

(a) Collected upstream of the mixing pond Inject flocculant into the suspension The first one is stirred in the stirring tank. process and (b) reduced agitation than in the first step; Condensation occurs in the first step at the stirring speed. Stir the suspension containing the concentrate and the second step.

(c) Speed of stirring in the second step and the third step of finding the slope.

(d) At least during the second step.

In the first step, flocculant is injected. from the light-emitting device through the suspension. Amount of light received by the light receiving device a fourth step of measuring; (e) Received light measured in the fourth step Pour the flocculant in the first step based on the amount The state of agglomeration of the suspended liquid is detected. The fifth step is to know.

(f) Velocity gradient obtained in the third step From the distribution, inspection is performed in the fifth step. Appropriate the known agglomeration state Determine the speed gradient as the appropriate speed gradient A sixth step of (g) Proper speed determined in the sixth step In the first step, corresponding to the degree gradient. Coagulation of suspensions injected with flocculant Determine aggregate formation time and ensure proper aggregation Seventh step as body formation time and, (h) supply of suspension to the mixing pond; and an eighth step of detecting the feed amount.

(+) The appropriate velocity gradient determined in the sixth step, the appropriate aggregate formation time determined in the seventh step, the supply amount of the suspension detected in the eighth step, and the aggregate formation pond. 8. A method for controlling agitation in an aggregate forming pond, characterized by comprising a ninth step of controlling agitation in the aggregate forming basin using a

[Function] The first stirring control method for an aggregate formation pond according to the present invention is as follows:
In an agitation control method for an aggregate formation pond, in which a flocculant is injected into a suspension with rapid stirring in a mixing basin, and then aggregates are formed by slow stirring in an aggregate formation pond. After injecting a flocculant into the suspension, the stirring speed is reduced, a velocity gradient corresponding to the reduced stirring speed is determined, and the flow is transferred from the light emitting device to the light receiving device via the flocculant-injected suspension. The amount of light received is measured, the aggregate formation time is detected from the amount of received light, the amount of suspension supplied to the mixing pond is detected, and the aggregate formation time and velocity gradient are determined from the suspension. The agitation control of the aggregate forming pond is performed according to the supply amount of the aggregate forming pond and the volume of the aggregate forming pond. This function allows the agitation control of the aggregate formation pond to be optimized in a short time while avoiding actually measuring the results of the agitation process.

Further, the second agitation control method of the flocculate formation pond according to the present invention is that after injecting the flocculant into the suspension while rapidly stirring it in the mixing basin, the flocculant is injected into the suspension and then slowly stirred in the flocculation basin. In a stirring control method for an aggregate formation pond formed by forming aggregates, a flocculant is injected into the collected suspension, the stirring speed is lowered, and a velocity gradient corresponding to the lowered stirring speed is determined, Measure the amount of light received by the light receiving device from the light emitting device through the suspension injected with the flocculant, and detect the agglomeration state of the suspension in which the flocculant is injected from the amount of received light. Of the velocity gradients, the velocity gradient that makes the agglomeration state appropriate is determined as the appropriate velocity gradient, and the agglomerate formation time of the suspension injected with the flocculant is determined in accordance with the appropriate velocity gradient to form the appropriate agglomerates. The amount of suspension supplied to the mixing pond is detected as the formation time, and the amount of the flocculation is determined according to the appropriate aggregate formation time, the appropriate velocity gradient, the amount of suspension supplied, and the volume of the aggregate formation pond. It has the function of controlling the agitation of the aggregate formation pond, and eliminates the visual observation and experience of the tester, and the agitation of the aggregate formation pond while avoiding the actual measurement of the results of the agitation process in the aggregate formation pond. In addition to the function of optimizing control in a short time, it also functions to execute stirring control in the aggregate formation pond with high precision.

[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 agitation control of an agglomerate formation pond is executed by an embodiment of the agitation control method for an agglomerate formation pond according to the present invention.

FIG. 2 is a sectional view specifically showing an example of the detection device of FIG. 1 for detecting the velocity gradient G and the aggregate formation time T in order to carry out an embodiment of the present invention.

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

FIG. 4 shows the detection of FIG. 1 for detecting an appropriate velocity gradient G♂ and an appropriate body formation time T♂ in order to carry out an embodiment of another stirring control method for an aggregate formation pond according to the present invention. FIG. 2 is a cross-sectional view specifically showing an example of the device.

Figure 5 shows the diameter d of the aggregate detected by the detection device in Figure 4;
It is a graph diagram showing the relationship between the number Nb9 body lnv and the effective density ρ and the velocity gradient G.

Figure 6 shows the supernatant water turbidity τ detected by the detection device in Figure 4;
FIG. 2 is a graph diagram showing the relationship between the sedimentation velocity S and effective density ρ of a music aggregate and the velocity gradient GL.

FIG. 7 is a sectional view showing a detection device in which four detection devices of FIG. 4 are arranged side by side.

First, let's discuss the present invention with reference to Figure 1! An actual suspension processing apparatus in which agitation control of an aggregate formation pond is executed using the 211 body formation pond agitation control method 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). 10
Reference numeral 6 denotes a mixing pond for a suspension and a flocculant, which is communicated with the landing well 102 via a supply pipe 108, and is provided with a stirring blade 110 that is rapidly rotated by a driving means, such as an electric motor 109.

! ! Reference numeral 2 denotes a ms body forming pond which is communicated with the A material land 108 via a supply pipe 114, and has a desired number of regions, for example, three regions 112A, .
, 112G, each with an agitator 113A.
, ~, 113G are arranged. Wl stirrer 113A,
. . . , 113G are driven by driving means such as ift motors 1115A, .
The stirring blade 116A is rotated slowly at ~onc.

~, 116C. The flocculant is injected and mixed in the mixing pond 106 and sent to the flocculation pond 1 through the supply pipe 114.
The suspension supplied to the aggregate forming pond 112 is first slowly stirred at a rotation speed nA for a predetermined period of time by the stirring blade 116A of the stirrer 113^ in the first region, that is, the first region 112A of the aggregate formation pond 112. The stirring blade 116 of the stirrer 113B is later transferred to the second region 112B.
It is slowly stirred by B for a predetermined period of time at a rotation speed of ns, and then transferred to the third region 112C and stirred by the stirrer 113C.
The stirring blade 116c slowly stirs at a rotation speed nc for a predetermined period of time.

Reference numeral 118 denotes a sedimentation tank connected to the aggregation formation tank 112, which is the final region of the agglomeration formation tank 112, that is, the third region 11.
The suspension supplied from 2C and in which aggregates or flocs were sufficiently formed was allowed to stand still.

The aggregates or flocs are precipitated and removed. 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 in the sedimentation tank 118, the treated water is passed through the treated water pipe 124 as treated water. The data is then sent to the appropriate subsequent equipment.

130 is specifically shown in FIG. 2, and is a detection device for outputting the velocity gradient G and the aggregate formation time Tt when the flocculant is injected into the suspension at a predetermined injection rate. It is connected to the landing well 102 via a supply pipe 132 and a pump 134, and a drain pipe 133 connects to the mixing pond 106.
It is open to the public at appropriate locations.

136 is a calculation device connected to the flow meter 138 disposed in the supply pipe 108 and the detection device GL130.

The velocity gradient GL and aggregate formation time TL detected by the detection device 13G and the flow rate (
In other words, the amount supplied to the mixing pond 106) Q and the aggregate formation pond 11217 measured in advance and inputted by manual operation etc.
) 8 areas 112A, ~, 112C17) Volume si v
A.

~, vc, and other necessary information is received, and using this information, the agitation units 11113A, ~, 11:Ic installed in each area 112^, ~, 112G of the aggregate formation pond 112 are received.
The rotational speed nA, . . . , nc is calculated.

That is, the calculation device 136 calculates the velocity gradient G given by the detection device 10, the velocity gradient G at the time of aggregate formation, the velocity gradient G in the aggregate formation pond 112, and the aggregate formation time T. From the relationship (however, α is a constant), each region 112A, ~, 11 of the aggregate formation pond 112
Velocity gradient G at 2C, (A), ~, G, (c)
be a constant α,

~, α. Using G, (A) = αAG,.

G, (B) = α, G1 G, (c) = αcG.

Therefore, the velocity gradient G, (^), ~, a, (c) is calculated as follows. However, the constant α, , ~, α.

are each region 112A, ~, 112 of the aggregate formation pond 112.
Considering the stirring intensity at G, α^ ≧ αn ≧ α.

and VAaA2+VBaa"+Vc ac"=vA+vlI
+vc. Here, each area 1 of the aggregate formation pond 112
12A, ~, 112G have equal volumes, that is, vA = vfi
=vc, the constant α4. ~． There is a relationship between αC as follows: α^2+αo2+αc2=3.

The velocity gradient G, (A), ~, G, (c) is the viscosity coefficient S of the suspension, the specific gravity η, the drag coefficient C, and the stirrer tOA.
.

~, 113 (: surface MiaA1~+aC of stirring blades 116A, ~, 116G and circumferential velocity υ,, ~, υ. and volume vA, ~, VC of each area 112^, ~, 112G of aggregate formation pond 112 Since it can be expressed using , it is possible to calculate ゛ from this relationship.
The circumferential speed υ, ..., υC can be expressed as υ^ = 2πrAn^ υ6 = 2πrAn^ υc = 2πrAn^ using the number of revolutions nA, ~, nc and the radius ",, ~, rc, and thus aAtlA', ~, aCυ j is a^ v^”=Ba^ π” rs”nA”alt
υB"' = 8 a 6 π3r m"n a"ac
Since it can be calculated as uc''=8acfc''rc'nc'.

8ac π'r,'nc'=sitVca,(c)'
Cη can be calculated, and the number of revolutions nA, . . . , ne can be calculated as. Therefore, the rotational speed nA, ~n, is.

It can be calculated as However, T1 is (vA+vlI+Vc)
/Q. As a result, the rotational speed nA, . f
f1Q) can be determined.

140 is a rotation speed controller connected to the arithmetic unit 136;
Rotational speed n A +- outputted by the arithmetic unit 136
-, Stir according to fic @ 11:lA, ~, 11:I
The rotation speed of the driving means 115^, 115G of C is controlled. Reference numeral 144 denotes a flocculant supply device, which supplies flocculant to the mixing pond 10 via a supply pipe 146 according to a preset injection rate WAl.
6 and injected against the suspension.

However, the detection device @13G according to the present invention
4 and the suspension from the landing well 102 via the supply pipe 132, and the velocity gradient Gt and The aggregate formation time TL is output as described below.

Both the suspension velocity gradient GL and the aggregate formation time Tt detected by the detection device 10 are given to the arithmetic unit 1136. In yt calculation system 211:16, the detection device 13
Each time the velocity gradient OL and the aggregate formation time Tt are input from 0, the aggregate formation pond 11 is changed as described above.
Rotation speed n A of stirring Jl 113A, -, 113C arranged in each area 112A, -, 112G of 2, respectively
+~+nC has been calculated.

The rotational speed n A + ~ output from the arithmetic unit l roller.

nc is given to the 1-rotation speed controller 140.

The rotational speed controller 140 controls the agitator 113A of the aggregate formation pond 112 according to the rotational speed n A + , n (, respectively).

~, 113G are driven. Here, the flocculation pond 112 is created by the mixing pond 106 and has a flocculant injection rate of WA.
A suspension that is + is being supplied.

By intermittently repeating the detection operation by the detection device 130 described above, aggregate formation in the suspension processing device can be performed with appropriate efficiency, and the processing time of the suspension can be shortened.

Further referring to FIGS. 2 and 3, the detection device 130
The configuration will be explained in detail.

1O is a batch-type stirring tank with an appropriate capacity, for example, lfL, in which a suspension containing a flocculant (hereinafter referred to as
11 (sometimes simply referred to as a suspension) is contained therein. Reference numeral 12 denotes a stirring blade disposed within the stirring tank IO, which is appropriately attached to the free end of the output shaft 16 of a drive means, for example, an electric motor 14, arranged below the stirring tank IO.

18 A suitable power supply (not shown) is provided by the beam 1Q19.
A light-emitting device connected to the Wl stirring tank 10, which is arranged on the side surface of the Wl stirring tank 10, converts light generated by a suitable light source such as a fluorescent lamp, tungsten lamp, halogen lamp, light-emitting diode, or laser emitting means into a suitable optical device. For example, the suspension 11 in the stirring tank lO is made into 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 CCD as a light receiving means, and is disposed on the side of the stirring tank 10 and receives light supplied as a parallel beam bundle by the 1 light emitting device 3!118. 0 light emitting device receiving light through suspension 11! The light given by 18.

Since the received light wave N20 is scattered or blocked by the aggregates, that is, the flocs 17 in the suspension 11, the received light wave N20 is received as scattered light or attenuated transmitted light.

The light receiving device 20 includes a light emitting device 18 to receive transmitted light.
The light emitting device 2t18 may be placed at a predetermined angle with respect to the parallel light beam from the light emitting device 2t18 in order to receive the scattered light. One light reception? In order to simplify the explanation, the light receiving device 20 may be arranged as follows.
It is assumed that the light emitting device 118 is opposed to the light emitting device 118. Although only one set of light emitting device 18 and light receiving device 20 is arranged in FIG. 2, the present invention is not limited to this, and multiple sets of light emitting device 18 and light receiving device 20 may be arranged. In particular, if the device ias and the received light wave W120 are arranged on the same horizontal plane, it is convenient for detecting the sedimentation state of the aggregates, that is, the flocs 17 with high precision.

Reference numeral 22 denotes a measuring device connected to the light receiving device 20 via a lead wire 21, which measures the amount of light received by the received light wave 2120 (hereinafter referred to as "received light amount"). In addition, the measurement bag 2122 calculates the fluctuation range of the received light amount I, (τ) before the injection of the flocculant and the received light amount ■ when flattened due to slow stirring by the stirring blade 12, from the measured received light amount I. That is, the predetermined value I
The difference between L and I□) Δ■ and the fluctuation period F are determined and output, and if desired, the amount of received light Ir(τ) after the stirring blade 12 is stopped and the settling of the flocs 17 is completed is determined. It is searched and output. In addition, the measuring device 22 measures the time from the start time t3 of slow stirring of the stirring blade 12 to the time t4 when the received light II becomes flat, that is, the aggregate formation time T (calculated from the measured received light II). It is output to ff1136 (see Figure 1).

2 is a supply pipe whose one end is opened to the agitation IfJto via the on-off valve 25, and the other end is communicated with the supply pipe 132 (see 1st [jU); 26 is connected to the flocculant supply source 28. One end of the flocculant supply pipe is connected to the other end of the on-off valve 27.
It is opened to the stirring tank IO through. Reference numeral 30 denotes a drain pipe, one end of which is opened at the bottom of the stirring tank 10, and the other end communicated with a drain pipe 133 via an on-off valve 32. 34 is a dark box, at least stirring tank lO1 light emitting device 2
118 and the light receiving device 20, and eliminates the influence of external light.

36 is a calculation device connected to the driving means 14 and the on-off valves 25.27, to which the driving means 14 gives the circumferential speed υ or rotational speed n of the stirring blade 12, and the on-off valves 25.27 give the suspension liquid. The supply amount M of the coagulant and the supply amount N of the flocculant are given, and the velocity gradient G is calculated using these information. In other words, the calculation device 5 calculates the capacity a of the stirring tank 10 (here M1N), the viscosity coefficient path of the suspension, the specific gravity η, the drag coefficient C, the surface v1a of the stirring blade 12, and the circumferential speed υ.
(that is, the number of revolutions n), the speed gradient Gt is calculated and outputted to the arithmetic unit fi 136 (see FIG. 1).

In addition, with reference to FIGS. 2 and 3, the detection device +:
The action of IO will be explained in detail.

After opening the on-off valve 32 and removing the suspension 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 period of time, and a predetermined amount M (for example, 1 volume) 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 t1
At this point, the stirring blade I2 begins to rotate rapidly, that is, at a high speed, by the driving means, for example, the electric motor 4.

Thereafter, by opening the on-off valve 27 for a predetermined time at time t, a predetermined amount N of flocculant is released.

The flocculant is injected from the flocculant supply source 28 through the flocculant supply pipe 26 into the stirring tank IO. ! As the aggregating agent, known flocculants such as polyaluminum chloride may be used as desired, where N is, for example, N/(M+N).
is the flocculant supply pipe! Coagulant injection rate WAl according to 1144
It is set appropriately so that.

Prior to the start of rapid rotation of the stirring blade 12, 1 light emitting S device 18. The light receiving device 20 and the measuring device 22 have been started, and the received light amount I of transmitted light through the suspension in the stirring tank 10 is measured.
are being measured.

The amount of light received until time t2, that is, the time when the flocculant is supplied, is equal to the initial concentration W of suspended matter contained in the suspension.
When a predetermined amount N of flocculant is injected at time t2, which has a constant value I (τ) corresponding to Since the liquid 11 is being stirred and moved rapidly in the stirring tank IO, the amount of light received by the light receiving device 20 increases slowly.

At time tU, when the stirring blade 12 starts to be rotated at a slow speed, that is, at a low speed, aggregates, that is, flocs 17 are further formed in the suspension If, and their diameter d gradually increases, and the suspension II is slowly stirred and moved in the stirring tank 10, so the received light Qt of the received light wave 'a20 increases and decreases little by little while increasing as a whole.

When time t4 is reached, there are enough aggregates or flocs 17 in the suspension 11! ! Since the suspension 11 is slowly stirred and moved in the stirring tank 10, the amount of light received by the light receiving device 20 becomes flat, and as the aggregates, that is, the flocs 17 pass, It's a predetermined value!
, and ■□. The fluctuation period at this time is shown as F in FIG.

Further, at time t5, when the rotation of the stirring blade 12 is stopped to stop the slow stirring, the aggregates, that is, the flocs 17 formed in the suspension 11 start to settle, so that the amount of light received by the light receiving device 20 I increases and decreases little by little at time t.
0 time t6 reaching a nearly constant value tr(τ) at 6
Hereinafter, the aggregates in the suspension 11, i.e. 70 pieces I7
no longer settles, the amount of received light ■ becomes a constant value Ir (
τ) is maintained.

For example, when using a kaolin suspension made by adding 251 g of kaolin to fresh water and injecting polyaluminum chlorite at an injection rate of 15 g/l, the device measures the amount of light received by the light receiving device 20. 22, the results were as shown in FIG.

The measuring device 22 determines, based on the amount of light received by the light receiving device 20, that is, the received light 91, that the flattening starts from the time t3 when slow stirring by the stirring blade 12 starts.
In other words, the time until the formation of the aggregates 17 is completed is measured, and the calculation device fi 136 calculates the aggregate formation time Tt.
(See Figure 1).

In addition, the calculation device roller is configured to have the suspension 1
The speed gradient at of 1 is calculated and sent to the arithmetic unit g113G (see FIG. 1).

In the above, the velocity gradient GL and the aggregate formation time Tt are simply detected by the detection device fi130, but if this is optimized as follows, the aggregate formation pond 112
Stirring control can be made more efficient.

That is, the computing device 36 is also connected to the measuring device 22 and the on-off valves 25 and 27 as shown in FIG. 4, and in addition to the above, the amount of received light is 1. (τ), the fluctuation range Δ■ of the amount of received light (■), the fluctuation period F, the suspension supply amount M, the flocculant supply iN, and other necessary information are given. As a result, the arithmetic unit 36
Parameters useful for determining the state of formation of aggregates, that is, flocs I7, are calculated.

In other words, @Sosou 2236 has the fluctuation range △I of the amount of received light ■
(volts) and the constant α, calculate the diameter d (cm) of the aggregate, that is, the floc 17, as d=αΔ■, and calculate the fluctuation period F (seconds) of the received light Bi and the stirring blade 1.
Using the circumferential speed υ (17 seconds) or rotational speed n (1/second) of 2 and constants β and β°, calculate the number N of aggregates, that is, flocs 17.
b (1/am3), and using the diameter d (cm) and number Nb (1/c 3) of the aggregate, that is, the floc 17, and the constant ε, the body 1V (c
The initial concentration W of suspended matter in the suspension was calculated from the received light 1ift (τ) (volts). (g/stand) and supply 1
Injection rate W A+ of coagulant determined from 1M and N (■gi
The effective density ρ (g/cm '3) Calculate 3, and if desired, calculate the time T and the constant δ
The settling velocity S of the floc 17 is calculated using
(cm/min), and using the amount of received light xr(τ) and a constant, the supernatant water turbidity τ after the flocs 17 have settled.
(degree) is calculated as τ=in ■tcτ). Here, the relationship between the parameters calculated by the calculation device 36 and the actual agglomeration state of the flocs 17 is the diameter d or the number of Nb2 bodies 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. Incidentally, the calculation device 36 may be configured not to calculate parameters that are not used.

Further, the calculation device 36 may optionally calculate at least the diameter d, the number Nb, the body gv, the effective density ρ, the sedimentation velocity S, and the supernatant water turbidity τ after the flocs 17 have settled. One value is sequentially stored for each speed gradient G at that time, and an appropriate value of the speed gradient Gt (that is, an appropriate speed gradient) G♂ is calculated. In other words, the arithmetic unit fa36 calculates the change in the velocity gradient GL,
Diameter d9 of the aggregate or floc 17 2v, number Nb,
Corresponding to when the change in effective density ρ or sedimentation velocity S begins to become steep, or when the change in supernatant water turbidity τ approaches a minimum, the velocity gradient Gt is determined as the appropriate velocity gradient G♂,
This can be outputted to the arithmetic unit 136 (see FIG. 1 and FIGS. 4 to 6), or the arithmetic device gf36
Of the aggregate formation time Tt determined from the received light riE, the aggregate formation time TL corresponding to the appropriate velocity gradient G♂ is determined as the appropriate aggregate formation time TL, and this is determined by the arithmetic unit 113.
6 (see Figure 1 and Figures t54 to 6).

This appropriate velocity gradient G♂ and appropriate aggregate formation time TL'
If these are used as the above-mentioned velocity gradient Gt and aggregate formation time TL, respectively, the stirring control of the aggregate formation pond 112 can be made more efficient.

In addition, in FIG. 2, in the arithmetic unit roller, ! Stirring blade 12
Although the speed gradient G1 is directly calculated from the circumferential speed V, here, the speed gradient Gt may be calculated using as the circumferential speed υ.

In FIG. 4, the detection device 130 containing only one stirring l7etO was explained, but with this, a large amount of time is required to detect the music collection state, and furthermore, the appropriate speed gradient Gt
Since it takes time to detect the appropriate aggregate formation time T♂, a plurality of (four in this case) stirring tanks may be arranged in parallel as shown in FIG.

In the detection device 130 of FIG. 7, a suspension supply S (not shown) and a flocculant supply source 28 are shared.

The configuration and operation are the same as those of the detection device shown in FIG. 4, except that a calculation device 8 and a control device 40 are added, and a part of the function of the calculation device 36 is assigned to the calculation device 8. Since they are substantially the same, each member will be referred to by the same reference numeral as in the detection device of FIG. 4 (and therefore, FIG. They are numbered and their detailed description will be omitted. The letters A, B, C, and D are added to the reference numbers to distinguish between the juxtaposed stirring vessels. Open/close valve 2
5A, 25D and 27^, ~, 27D are Wl stirring tanks 10A, ~.

1 (suspension II^ in 10, ~, JJl for 110
It is opened as appropriate to match the injection rate of the concentration agent.

The computing device 38 is connected to the measurement bags fi22A, -, 22D and the computing devices 36A, -, 36D.

~, the velocity gradient G calculated in 36D (the velocity gradient Gt that makes the aggregate formation state appropriate is the appropriate velocity gradient G)
From among the aggregate formation times Tt determined as L'' and calculated by the calculation devices 36A to 36D, the aggregate formation time Tt corresponding to this appropriate velocity gradient G♂ is determined as the appropriate aggregate formation time TL''. The controller 2140 sends the appropriate velocity gradient Gt" and the appropriate aggregate formation time Tt" to the arithmetic unit 136 (see FIG. 1). stirring blade 12A
, .

In addition, in the above description, the stirrer 11:lA, ~, 113c
Although the agitation control of the agglomerate formation pond 112 is executed by controlling the rotational speed nA, ~, n (!2), the present invention is not limited to this, and the agitators 113A, ~,
, 113G rotational speed or aggregate formation pond 112A,
Agitation control of the aggregate formation pond 112 may be achieved by controlling the volume of the aggregates 112C, 112C, and the like.

(3) Effects of the invention As is clear from the above, the l! 2 The first agitation control method for the agglomerate formation pond is to inject a flocculant into the suspension while rapidly agitating it in the mixing basin, and then slowly stirring it in the agglomerate formation pond to form agglomerates. In the agitation control method for an agglomerate formation pond, (a) a first step of injecting a flocculant into a suspension collected upstream of the mixing pond and stirring it in a stirring tank; (b) a second step of stirring the suspension into which the flocculant was injected in the first step at a stirring speed lower than that of the first step; (c) a step of determining the speed gradient of stirring in the second step; 3
With the process.

(d) at least in the second step, a fourth step of measuring the amount of light received from the light emitting device to the light receiving device via the suspension into which the flocculant was injected in the first step; a fifth step of determining the aggregate formation time of the suspension into which the flocculant was injected in the first step from the amount of received light measured in the fourth step;

(f) a sixth step of detecting the amount of suspension supplied to the mixing pond;

(g) Velocity gradient obtained in the third step and 1! obtained in the fifth step! and a seventh step of controlling the agitation in the aggregate formation pond using the J aggregate formation time, the supply amount of the suspension detected in the step tIS8, and the volume of the aggregate formation pond. .

(i) It has the effect of eliminating the visual observation and experience of the tester, and (ii) it has the effect of shortening the time required to control stirring of the aggregate formation pond.

Further, the second agitation control method of the flocculate formation pond according to the present invention is that after injecting the flocculant into the suspension while rapidly stirring it in the mixing basin, the flocculant is injected into the suspension and then slowly stirred in the flocculation basin. A stirring control method for an aggregate formation pond formed by forming aggregates includes: (a) an rtSl step in which a flocculant is injected into the suspension collected upstream of the mixing pond and the mixture is stirred in a stirring tank; .

(b) a second step of stirring the suspension into which the flocculant was injected in the first step at a stirring speed lower than that of the first step; and (c) a speed gradient of stirring in the second step. The third step is to find
With the process.

(d) at least in the second step, a fourth step of measuring the amount of light received from the light emitting device to the light receiving device via the suspension into which the flocculant was injected in the first step; A fifth step detects the agglomeration state of the suspension into which the flocculant was injected in the first step from the amount of received light measured in the fourth step.
With the process.

From among the velocity gradients found in the third CD step,! 8
(g) a first step corresponding to the appropriate speed gradient determined in the sixth step; Find the aggregate formation time of the suspension injected with the flocculant, and check the appropriateness! (h) an eighth step of detecting the amount of suspension supplied to the #2 blend; (i) an appropriate velocity gradient determined in the sixth step; The agitation control in the aggregate formation pond is performed using the appropriate aggregate formation time determined in the seventh step, the supply amount of the suspension detected in the eighth step, and the volume of the aggregate formation pond. In addition to the effects (i) and (ii) above, (
iii) It has the effect of highly accurate stirring control of the aggregate formation pond.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an actual suspension processing apparatus in which agitation control of an agglomerate formation pond is executed according to an embodiment of the agitation control method for an agglomerate formation pond according to the present invention, and FIG. A sectional view specifically showing an example of the detection device shown in FIG. 1 for detecting the velocity gradient Gt and the aggregate formation time TL in order to carry out an embodiment of the invention, and FIG. 3 is a cross-sectional view showing the detection device shown in FIG. 2. FIG. 4 is an operation explanatory diagram for explaining the operation of the apparatus, and FIG. A cross-sectional view specifically showing an example of the detection device shown in FIG. 1 that detects T♂, and FIG. Figure 6 is a graph showing the relationship between the velocity gradient Gt and the velocity gradient GL. The graph shown in FIG. 7 is a sectional view showing a detection bag in which four detection devices of FIG. 4 are arranged side by side. 102・・・・・・・・・・・・・・・Waterfall well +
06・・・・・・・・・・・・・・・Mixing pond +1
2・・・・・・・・・・・・・・・ Aggregate formation pond +18・・・・・・・・・・・・・・・Settling basin 1
20・・・・・・・・・・・・・・・Filtration pond 13
0・・・・・・・・・・・・・・・Detection device 13
5・・・・・・・・・・・・・・・ Arithmetic device 13
8・・・・・・・・・・・・・・・・・・Flow meter 140
・・・・・・・−・・・・・・・・・・Rotation speed controller 1
44・・・・・・・・・・・・・・・Flocculant supply device lO・・・・・・・・・・・・・・・・Stirring tank 11...・・・・・・・・・・・・・・・・・・Suspension I2・・・・・・・・・・・・・・・・・・Stirring blade 14・・・・・・・・・・・・・・・・・・・・・
Driving means 16・・・・・・・・・・・・・・・・・・
・Output shaft 18・・・・・・・・・・・・・・・・・・
・Light-emitting device 20・・・・・・・・・・・・・・・・・・
・・Light receiving device 22・・・・・・・・・・・・・・・・
・・・Measuring device 24・・・・・・・・・・・・・・・
・・・・Supply pipe 25.27・・・・・・・・・・・・・
・・・Opening/closing valve 26・・・・・・・・・・・・・・・・・・
・・・a Additive supply pipe 28 ・・・・・・・・・・・・・・・
...Flocculant supply source 30...
・・・－・・・・・・Drain pipe 32・・・・・・・・・・・・
......Opening/closing valve 34...
・・・・・・・・・Dark box 36.38・・・・・・・・・
...... Arithmetic device 40 ......
・・・・・・Control device patent applicant Ebara Infilco Co., Ltd. Ebara Research Institute Co., Ltd. Agent Patent attorney Takashi Kudo G% (+
/sec) Figure 6 G% (1/sec)

Claims (8)

[Claims] (1) In an agitation control method for an aggregate formation pond, in which a flocculant is injected into a suspension while being rapidly stirred in a mixing basin, and then aggregates are formed by slow stirring in an aggregate formation basin. (a) a first step of injecting a flocculant into the suspension collected upstream of the mixing pond and stirring it in a stirring tank; (b) agitation that is lower than the first step; (c) a third step of determining the speed gradient of the stirring in the second step;
(d) At least in the second step, a fourth step of measuring the amount of light received by the light emitting device to the light receiving device via the suspension into which the flocculant was injected in the first step. (e) a fifth step of determining the aggregate formation time of the suspension into which the flocculant was injected in the first step from the amount of received light measured in the fourth step; a sixth step of detecting the supply amount of the suspension; (g) the velocity gradient determined in the third step, the aggregate formation time determined in the fifth step, and the suspension detected in the sixth step; a seventh step of controlling agitation in the aggregate forming pond using the supply amount of the aggregate forming pond and the volume of the aggregate forming pond. (2) In an agitation control method for an aggregate formation pond, in which a flocculant is injected into a suspension while being rapidly stirred in a mixing basin, and then aggregates are formed by slow stirring in an aggregate formation basin. (a) a first step of injecting a flocculant into the suspension collected upstream of the mixing pond and stirring it in a stirring tank; (b) agitation that is lower than the first step; (c) a third step of determining the speed gradient of the stirring in the second step;
(d) At least in the second step, a fourth step of measuring the amount of light received by the light emitting device to the light receiving device via the suspension into which the flocculant was injected in the first step. (e) a fifth step for detecting the agglomeration state of the suspension into which the flocculant was injected in the first step from the amount of received light measured in the fourth step;
(f) A sixth step of determining, from among the velocity gradients determined in the third step, a velocity gradient that makes the aggregation state detected in the fifth step appropriate as the appropriate velocity gradient; (g) In response to the appropriate velocity gradient determined in the sixth step, the aggregate formation time of the suspension in which the flocculant was injected in the first step is determined, and the seventh step is determined as the appropriate aggregate formation time. (h) an eighth step of detecting the amount of suspension supplied to the mixing pond; (i) detecting the appropriate velocity gradient determined in the sixth step and the appropriate coagulation determined in the seventh step; and a ninth step of controlling the stirring in the aggregate formation pond using the aggregate formation time, the supply amount of the suspension detected in the eighth step, and the volume of the aggregate formation pond. A stirring control method for an aggregate formation pond, characterized by: (3) (i) In the fifth step, the aggregation state of the suspension 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 second step. and (ii) in the sixth step, a velocity gradient corresponding to when the change in the number of aggregates starts to become steep is determined as an appropriate velocity gradient.
2) Agitation control method for an aggregate formation pond as described in section 2). (4) (i) In the fifth step, by calculating the diameter of the aggregate from the fluctuation range when the amount of received light is flattened,
Detecting the aggregation state of the suspension, and (ii) determining, in the sixth step, a velocity gradient corresponding to when the change in the diameter of the aggregate starts to become steep as an appropriate velocity gradient. Claim No. (
The method for controlling agitation in an aggregate formation pond according to item 2) or item (3). (5) (i) In the fifth step, calculate the number of aggregates from the fluctuation period when the amount of received light is flattened and the stirring speed in the second step, and the width of fluctuation when the amount of received light is flattened. (ii) detecting the agglomeration state of the suspension by calculating the diameter of the aggregates from the number of aggregates and calculating the volume of the aggregates from the number and diameter of the aggregates; The aggregate formation pond according to claim (2), characterized in that the velocity gradient corresponding to when the changes in the number, diameter, and volume of aggregates start to become steep is determined as the appropriate velocity gradient. Stirring control method. (6) (i) In the fifth step, the number of aggregates is calculated from the fluctuation period when the amount of received light is flattened and the stirring speed in the second step, and the width of fluctuation when the amount of received light is flattened. The aggregation state of the suspension can be determined by calculating the diameter of the aggregates from the above, 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. and (ii) in the sixth step, a velocity gradient corresponding to when the change in the number and diameter of the aggregates begins to become steep and the change in effective density begins to become slow is determined as the appropriate velocity gradient. A stirring control method for an aggregate formation pond according to claim (2). (7) (i) In the fifth step, calculate the supernatant water turbidity after the aggregates have been precipitated from the amount of received light when the amount of received light becomes flat after the stirring in the second step is stopped. (ii) In the sixth step, the velocity gradient corresponding to when the change in supernatant water turbidity starts to become minimum is determined as the appropriate velocity gradient. Characteristic Claim No. (2)
A stirring control method for an aggregate formation pond as described in Section 1. (8) (i) In the fifth step, the aggregation of the suspension is determined by calculating the sedimentation rate of the aggregate from the time from when the stirring in the second step is stopped until the amount of received light becomes flat. Claims characterized in that the state is detected, and (ii) in the sixth step, a velocity gradient corresponding to when the change in sedimentation velocity of the aggregate starts to become steep is determined as an appropriate velocity gradient. The method for controlling agitation in an aggregate formation pond according to item (2).