JP2002058910A - Flocculating/separation equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide flocculating/separation equipment which is excellent in separation efficiency of flocculated precipitates and treated water and can attain small-sizing of the equipment. SOLUTION: The flocculating/separation device is provided with a center well 10 having a bottom part communicated with the tank in the tank 2 having an opened upper part and has a tank structure with which waste water added with a flocculating agent is separated to flocculated precipitates and treated water. Further a waste water introducing means 12A, a waste water stirring means 23 and a waste water straightening means 36 are installed in the center well from an upper part to a lower part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a coagulation-sedimentation separation method in which a flocculant is added to wastewater to separate solids and suspended matter contained in the wastewater as coagulation (also referred to as coagulation-sedimentation) to obtain treated water. The present invention relates to an apparatus (hereinafter, also simply referred to as a separation apparatus).

[0002]

2. Description of the Related Art As shown in FIG. 8, a conventional coagulation / sedimentation / separation apparatus comprises a stirring tank 101 for adding a coagulant to wastewater to cause a coagulation reaction, and a sedimentation tank (sedimentation tank) for precipitating agglomerates by the coagulation reaction. ) 102. The stirring tank 1 shown in FIG.
Numeral 01 is composed of a first stirring tank 101A for adding an inorganic coagulant and stirring rapidly (high speed), and a second stirring tank 101B for adding a polymer coagulant and stirring slowly. Wastewater containing aggregates treated in the stirring tank 101 is supplied to the center well 103 of the settling tank 102.
To be sent inside.

The sedimentation tank 102 has a cylindrical body of a center well 103 at the upper center of the tank, and an outlet 104 for coagulation and sedimentation is provided at the bottom of the tank, and a drainage part 105 for treated water is provided at the upper end of the tank. Further, a stirring blade 106 for collecting the coagulated sediment and sending the collected sediment to the discharge port 104 is formed at the upper part of the discharge port 104 so as to be rotatable by a motor 107 at the upper part of the tank. The wastewater containing the condensate that has entered the center well 103 descends and the condensate precipitates at the bottom of the tank, and the treated water is discharged from the drain 105 at the upper end of the tank. Aggregate sedimentation is caused by stirring blade 1
06 is sent to the discharge port 104 by the low speed rotation, and the discharge port 1
04.

As described above, the conventional separation apparatus has a two-tank structure including the stirring tank 101 for performing the coagulation reaction on the wastewater and the sedimentation tank 102 for separating the coagulated matter generated by the coagulation reaction. General.

[0005] Conventional coagulation-sedimentation separation devices include:
(A) An inclined plate is arranged on the outer periphery of the center well of the separation tank (corresponding to the sedimentation tank) to improve the separation of the aggregate of the treated water passing through the center well and rising on the outer periphery of the center well. (2) A structure in which a stirrer is provided in the center well to promote the agglutination reaction of aggregates. (C) A rising area of the treated water on the outer periphery of the center well. There is known a structure in which a rectifying plate is disposed in a rectifying plate, a filtration layer formed of sludge is formed below the rectifying plate, and the ability to separate aggregates in the treated water is enhanced.

[0006]

However, since the coagulation reaction requires a residence time, a tank for performing the coagulation reaction needs to have a certain size, and it has been difficult to reduce the size of the entire apparatus. For this reason, a structure has been devised in which the agitation reaction is promoted by stirring in the pipe. However, this structure has a problem that a blockage of the pipe is liable to occur due to adhesion and growth of solids.
In addition, in the structure provided with the inclined plate and the rectifying plate of (a) and (c), the flow rate of the treated water in the inclined plate and the rectifying plate portion is low,
There was an obstacle that the separated aggregates were deposited or adhered and grown on the inclined plate and the current plate.

In the above-mentioned (b) in which a stirrer for promoting the agglutination reaction is provided in the center well, when the stirring is carried out so as to obtain a sufficient effect of promoting the agglutination reaction, the swirling caused by the agitation is performed. The water flow affected the water flow in the entire tank, and the suspended aggregates were lifted up in the tank in an attempt to settle, and the separation efficiency of the aggregates was reduced. Conventionally, a reduction in the size of the separation device has been desired. However, as described above, the effect of accelerating the agglutination reaction is obtained, and the swirling water flow is prevented from affecting the entire water flow in the separation tank. It was not easy to make a device.

It is an object of the present invention to provide a coagulation / sedimentation / separation apparatus which can cope with coagulation / sedimentation and treated water and can be reduced in size.

[0009]

Means for Solving the Problems In order to achieve the above-mentioned object, the invention according to claim 1 is provided in a tank having an open upper part.
An apparatus having a tank structure in which a bottom is provided with a center well communicating with the inside of a tank, and a wastewater added with a flocculant is separated into a flocculated sediment and treated water. It is characterized in that stirring means and wastewater rectification means are provided.

According to the first aspect of the present invention, the wastewater containing the flocculant introduced into the center well is promoted by the agitation of the wastewater stirring means to become the wastewater containing the aggregate.
This wastewater is rectified by the wastewater rectification means at the bottom and flows down to the bottom of the tank. Since wastewater containing aggregates (this wastewater is treated water) flows down through the wastewater rectification means, there is no agglomeration of aggregates at the bottom of the tank, so that separability between treated water and aggregates is good. . In the invention of claim 1, since the center well having the waste water stirring means and the waste water rectification means is provided in the tank, it is not divided into two separate tanks as in the related art.
The coagulated sediment can be satisfactorily separated and separated from the treated water in one tank, and the apparatus can be made compact.

According to a second aspect of the present invention, in order to achieve the above object, the coagulated sediment in the wastewater flowing down through the wastewater rectification means of the center well is formed at the bottom of the tank. It is characterized in that a sedimentation guiding means for leading to the discharge port is provided.

According to the second aspect of the present invention, the coagulated sediment in the wastewater flowing down from the center well is sent to the sediment discharge port by the sedimentation induction means and removed from the tank.

According to a third aspect of the present invention, in order to achieve the above object, in the second aspect of the present invention, the sedimentation inducing means at the bottom of the tank is moved at such a low speed that the coagulated sediment is not wound into the tank. Features.

According to the third aspect of the present invention, since the sediment inducing means in the tank is moved at a low speed, the wastewater containing the coagulated sediment which has exited the center well can smoothly coagulate and sediment without rolling up the coagulated sediment at the bottom of the tank. Can be sent to the outlet.

[0015]

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG. First, the structure of the coagulation / sedimentation / separation apparatus 1 will be described with reference to FIG. The tank body 2 of the separation device 1 has a conical bottom surface 2A projecting outward and an upper end opening 2B.
And the shape. A central portion of the conical bottom surface 2A is a concave portion 4 also serving as a sediment discharge port 3, and a sediment extracting pipe 5 is connected to the concave portion 4. A drain gutter 6 is provided around the inner peripheral surface of the tank body 2 near the opening 2B for flowing the overflow of the treated water, and a drain port 7 is provided in a part of the drain gutter 6, and a drain pipe is provided in the discharge port 7. 8 are connected.

In the center of the tank body 2, a center well 10 formed of a cylindrical body is disposed vertically with its lower part communicating with the bottom of the tank body 2. The upper end of the center well 10 is fixed to a crosspiece 11 provided laterally in the opening 2B of the tank body 2. As shown in FIG. 2, the upper part of the center well 10 has a three-stage structure of a bar member 11, a middle bar member 11A, and an upper bar member 11B.

On the upper side of the center well 10, an introduction pipe 12A of a waste water conduit 12 (see FIG. 4) for introducing waste water into the center well 10 is provided horizontally. The wastewater conduit 12 is provided with a wastewater feed pump 13 (see FIG. 4) so that wastewater can be introduced into the center well 10.

As shown in FIGS. 1 and 2, the center well 1
0, a rotary shaft 15 is inserted from above the opening 2B of the tank body 2 to the recess 4 of the bottom surface 2A of the tank body (2).
Bearing 17 and bearing 1 attached to middle stage member 11A
8 rotatably supported.

Near the bottom surface of the rotary shaft 15 in the tank, a blade 16 serving as a precipitation inducing means is attached. The blade 16 is formed obliquely so as to rotate close to the bottom surface 2A. As shown in FIG. 2, the upper end of the rotating shaft 15 is connected to the lower drive shaft 20 of the dual shaft motor 20 fixed to the upper rail member 11B.
A is connected to the motor A via a coupling 21, and the rotating shaft 15 is rotatable at a low speed by the drive of the double shaft motor 20.

Further, as shown in FIG.
A stirring blade 23 as a waste water stirring means is disposed at a position below the inlet of the introduction pipe portion 12 </ b> A in the inside 0. The stirring blade 23 is attached to a lower part of a rotary cylinder 22 which is externally mounted on the rotary shaft 15 and has an upper part rotatably supported. As shown in FIG. 2, the upper part of the rotary cylinder 22 is supported by the bearing 24 on the crosspiece member 11, and the driven wheel 25 is attached to the upper end.

On the other hand, as shown in FIG. 2, on one side of the double-shaft motor 20, a vertically oriented transmission shaft 26 is supported by upper fixing members 27 and bearings 28 and 29 attached to the beam member 11. ing. An upper sprocket 30 of the transmission shaft 26 is rotatably connected to a drive sprocket 31 attached to an upper drive shaft 20B of the double shaft motor 20 by a chain 32. Also, transmission shaft 2
6 is connected to the driven wheel 25 of the rotating cylinder 22 by a chain 34. The rotation of the stirring blade 23 of the rotary cylinder 22 by the driving of the double shaft motor 20 causes the rotation of the rotary shaft 1.
The drive wheel 31, the upper wheel 30, the lower wheel 33, and the driven wheel 25 are rotated so as to rotate at a predetermined high speed from the blade body 16 of FIG.
Gear ratio is set. The rotation of the double-shaft motor 20 causes the blade 16 to rotate at a low speed via the rotary shaft 15, and the stirring blade 23 to rotate at a high speed via the rotary cylinder 22.

The stirring blades 23 in the center well 10
A rectifying means 36 for rectifying waste water swirled by the stirring blades 23 and flowing down from the lower end of the center well 10 is attached to a lower portion of the center well. The flow straightening means 36 has a thick plate structure 38 in which a number of flowing water holes 37 to 37 are vertically formed. The planar shape of the flowing water holes 37 to 37 in the thick plate structure 38 is, for example, a lattice-shaped flowing water hole 37A in the thick plate structure 38 in FIG. 3A and a honeycomb-shaped flowing water in the thick plate structure 38 in FIG. The hole 37B and the thick plate structure 38 in FIG. 3C can be formed as radial water holes 37C. Note that FIG.
G in (B) and (C) is a shaft hole of the rotating shaft 15. In this example, grid-shaped water holes 37A to 37A are used.

The wastewater conduit 12 of the separation apparatus 1 is provided with a coagulant supply means and a chemical supply means for pH adjustment. As shown in FIG. 4, a flow measuring device 40 is interposed in the wastewater conduit 12, and the amount of wastewater supplied to the separation device 1 can be measured.

On the other hand, as shown in FIG. 4, a first coagulant tank 42 containing an inorganic coagulant, an alkali tank 44 containing an alkali agent for pH adjustment, and an acid agent for pH adjustment are provided near the waste water conduit 12. The inserted acid tank 46 is arranged, and each feed pump 42A,
Supply conduits 42B, 44B, 44A, 46A, respectively.
46B is led to the suction side of the wastewater feed pump 13 so that each chemical can be supplied to the wastewater in the wastewater conduit 12.

The discharge side of the wastewater feed pump 13 has p
An H measuring device 48 is arranged to measure the pH of the wastewater, and the measured value controls the feed pump 46A of the acid tank 46 to adjust the pH of the wastewater. A second coagulant tank 50 containing a polymer coagulant is disposed near the discharge side of the wastewater feed pump 13.
The polymer flocculant can be supplied to the wastewater of the waste water pipe 12 through the supply conduit 50B via A.

Next, examples of use of the separation apparatus 1 will be described with reference to FIGS.
This will be described with reference to FIG. Now, the wastewater feed pump 13 interposed in the wastewater conduit 12 and the two-axis motor 20 of the separation device 1 are in an operating state. Further, the feed pumps 42A, 44A, 46A, 50A of the first coagulant tank 42, the alkali tank 44, the acid tank 46, and the second coagulant tank 50 are also in a state where they can be operated. Thus, the flow rate of the waste water in the waste water conduit 12 is measured by the flow measuring device 40, and the supply conduits 42B, 44B,
46B adds an inorganic coagulant, an alkaline agent, or an acid agent to the wastewater. Next, after the pH of the wastewater is measured by the pH measuring device 48, the polymer flocculant is added through the supply conduit 50B.

As shown in FIG. 5, the wastewater H to which each treatment agent has been added is introduced into the center well 10 through the introduction pipe 12A of the separation device 1. Since the wastewater H introduced into the center well 10 is swirled by the high-speed rotation of the stirring blade 23,
The suspended matter and the like in the wastewater H are aggregated T
And turns with wastewater H. By sequentially introducing the wastewater H into the center well 10, the wastewater H containing the aggregate T flows downward, is rectified through the rectifying means 36, and is discharged from the lower part of the center well 10 to the bottom of the tank. You.

Next, as shown in FIG. 5, the wastewater H containing the aggregate T rises between the inner peripheral surface of the tank and the outer peripheral surface of the center well 10 from the bottom of the tank. During the ascent, the aggregate T becomes a sedimentary layer and is separated, and the separated wastewater H of the aggregate T overflows the upper surface as the treated water S, and the receiving trough 6
And is sent to a predetermined location by a drain pipe 8 through a drain port 7.

On the other hand, the sediment of the aggregate T is guided to the recess 4 of the bottom surface 2A by the low-speed rotation of the blade body 16 on the inner bottom surface of the tank, and is discharged to a predetermined portion by the sediment removal pipe 5.

Since the separation device 1 has the stirring blades 23 provided in the upper part in the center well 10 and the rectification means 36 provided below the stirring blades 23, the same function as the conventional stirring tank 101 shown in FIG. By agitating the separation device 1 at the upper part in the center well 10, the agglutination reaction is promoted in the wastewater to which the flocculant is added, and the wastewater containing the agglomerated matter (treated water)
It can be. Since the blade body 16 on the bottom of the tank rotates at a low speed, the generated aggregates are not broken. Also,
In the portion of the center well 10 where the wastewater is supplied from the introduction pipe portion 12A, the water flow is partially biased, but the drift can be eliminated by the stirring blades 23.

The swirling water flow generated by the stirring blades 23
6 allows the water to flow down to the bottom of the tank as rectified water,
Agglomerates do not roll up. In addition, the wing body 1
No. 6 does not wind up agglomerates due to low speed rotation. Therefore, aggregates can be favorably settled, and solid-liquid separation can be effectively performed. Therefore, according to the separation device 1 of the present embodiment, the entire device can be reduced in size.

The rectifying means 36 in the center well 10 eliminates the swirling flow generated by the stirring means (the stirring blade 23),
By making a stable and uniform downward flow, the solid-liquid separation treatment (separation of coagulated sediment and treated water) is made more efficient. In the above-mentioned conventional devices (a) and (b) in which a flow straightening plate is provided outside the center well of the separation tank, since the flow straightening plate is arranged at a portion where the flow rate of the treated water is low, the flow straightening plate is aggregated. There was an inconvenience that the current plate was closed due to the adhesion of the object and its growth. In the present embodiment, since the current plate is provided in the lower portion of the center well where the flow velocity is high, the conventional disadvantage is solved.

It is preferable that the hole 37 has a diameter of about 100 mm and a thickness of 100 mm or more. In order to obtain a stable rectification (water flow), it is desirable to provide a center well portion having a length twice or more the thickness of the rectification means below the rectification means 36.

Although the rectifying means 36 has a plate shape, the rectifying means 36 may employ an appropriate structure capable of rectifying the upper swirling flow. For example, as shown in FIG. 6 (A), a vertically oriented plate piece 55 having an inclined cutout 55A provided on the upper side is symmetrically arranged on the inner peripheral surface of the center well 10 as shown in FIG. 6 (B). It may be done. The swirling flow of the plate piece 55 is gradually decelerated by the notch portion 55A, so that the aggregate is not broken and the downward flow can be satisfactorily performed. In addition, each plate piece 5
The size and shape of the center well 10 are, for example, the width of the center well 10.
About 75 to 100% of the inner diameter of the center well 10
, The oblique angle is about 20 to 30 degrees, and the number of the plate pieces 55 is desirably four or more. This rectification means 3
The center well 10 of the separation device 1 of FIG.

In the above-described embodiment, the blade 16 that rotates at a low speed near the bottom of the tank is used as the precipitation inducing means for guiding the coagulated sediment to the discharge port 3, but the sedimentation inducing means is to wind up the coagulated sediment at the bottom in the tank. In addition, means that can be sent to the outlet 3 can be widely used. The precipitation inducing means may be, for example, a movable plate that reciprocates near the bottom surface in the tank (not shown).

[0036]

According to the present invention, it is possible to obtain a separation apparatus which can separate coagulated sediment and treated water well and can be miniaturized.

[Brief description of the drawings]

FIG. 1 is a structural view of a separation device according to an embodiment of the present invention.

FIG. 2 is an enlarged structural view of a main part of FIG.

FIGS. 3A and 3B are enlarged perspective views of a rectifying structure, in which FIG. 3A shows a grid type flowing water hole, FIG. 3B shows a honeycomb type flowing water hole, and FIG. 3C shows a radial type flowing water hole.

FIG. 4 is a diagram illustrating a use state of the separation device.

FIG. 5 is an operation diagram of the separation device.

6A and 6B show another example of the rectifying structure, in which FIG. 6A is a perspective view of a rectifying plate constituting the rectifying structure, and FIG. 6B is a plan view of a center well showing a rectifying plate arrangement state.

FIG. 7 is a cross-sectional view illustrating a separation device provided with a rectifying structure using the rectifying plate of FIG.

FIG. 8 is a diagram illustrating a use state of a conventional separation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 (Coagulation sedimentation) separation apparatus 2 Tank main body 3 Outlet 6 Receiving trough 7 Drainage outlet 10 Center well 12A Introducing pipe part 15 Rotating shaft 16 Blade body 20 Double shaft motor 22 Rotating cylinder 23 Stirring blade 36 Rectifying means 37 Flowing water hole 38 Thickness Plate structure 55 Plate piece 55A Notch

Claims (3)

[Claims] 1. An apparatus having a tank structure provided with a center well having a bottom portion communicating with the inside of a tank having an open top and separating wastewater containing a coagulant into coagulated sedimentation and treated water. A coagulation / sedimentation / separation apparatus characterized in that a wastewater introduction means, a wastewater stirring means, and a wastewater rectification means are provided in a center well from an upper part to a lower part. 2. A sedimentation guiding means for guiding coagulated sediment in wastewater flowing down through a wastewater rectification means of a center well to a sedimentation discharge port is provided at a bottom portion in the tank. 3. The coagulation sedimentation separation device according to item 1. 3. The coagulation / sedimentation separation apparatus according to claim 2, wherein the sedimentation guiding means at the bottom of the tank is moved at such a low speed that the coagulation sediment is not wound up in the tank.