JP3409036B2 - Forced circulation type separation device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for solid-liquid separation of water to be treated containing suspended substances such as colloidal substances and fine particles. The present invention relates to a forced circulation type separation device that agglomerates the mixed liquid and separates it into floc (flocculated sludge) and clear water .

[0002]

2. Description of the Related Art When removing suspended solids and flocs in the waste water, gravity settling is usually carried out in a sedimentation tank or the like, but this requires a large site and a long residence time, and fine suspended solids are required. In some cases, they could not be completely removed and were spilled. Further, in the coagulation sedimentation treatment, a mixing tank, a floc forming tank, and a sedimentation separation tank must be separately provided, which not only requires a larger area but also has a problem that operation management becomes complicated.

Therefore, the present inventors have already provided a coagulation / separation device for performing coagulation and solid-liquid separation in one tank without providing a separate coagulation tank (coagulation floc formation tank) or a vast sedimentation tank. There is. FIG. 11 is a schematic cross-sectional view showing an outline of the aggregation / separation device as a conventional example.

In FIG. 11, 1 is a solid-liquid separation tank consisting of a circular tank, 2 is a raw water introducing means connected to the lower part of the solid-liquid separating tank 1, and the raw water introducing means 2 is a colloidal substance or a suspension. The mixed liquid in which the water to be treated containing the turbid substance and the coagulant are mixed is introduced into the solid-liquid separation tank 1. Three
Is a porous member arranged in the solid-liquid separation tank 1 and having a plurality of water passage holes. The porous member 3 divides the inside of the solid-liquid separation tank 1 into a lower aggregation region 4 and an upper separation region 5. ing. Reference numeral 6 denotes an axial flow type stirring blade arranged in the lower aggregation region 4, and this stirring blade 6 serves as a circulation flow forming means for stirring the raw water introduced into the solid-liquid separation tank 1. It is designed to be driven by rotation. Reference numeral 8 denotes a vertical guide plate (baffle plate) provided on the inner wall surface of the lower aggregation region 4. The guide plate 8 is a circumferential direction generated in the lower aggregation region 4 by stirring the raw water by the stirring blade 6. The swirling flow of is converted into an upward flow. Reference numeral 9 is a treated water outlet means that is connected to the upper portion of the solid-liquid separation tank 1 to lead out the treated water from the upper separation area 5.

Next, the operation will be described. Solid-liquid separation tank 1
The mixed liquid introduced from the raw water introducing means 2 into the inside is stirred by the stirring blade 6 in the lower aggregation region 4 of the solid-liquid separation tank 1. As a result of the stirring, in the lower aggregation region 4, a circulation flow in the up-and-down direction is generated by the guide plate 8 to agglomerate the colloidal substances and suspended substances contained in the admixture to form a floc floc group and A circulating flow in the horizontal direction is generated just below the member 3. The circulating flow gives an inertial force in the horizontal direction to the flocculation floc group formed of the colloidal substance or the suspended substance formed in the mixed liquid, and the flocculation floc group is separated by the inertial force, and the porous member 3 is The treated water separated by the coagulated flocs that have passed through is admitted to the upper separation area 5 and is led out from the treated water lead-out means 9.

[0006]

Since the conventional flocculation / separation device is constructed as described above, the solid-liquid separation tank 1 in which the mixed liquid is circulated and circulated by the rotation of the stirring blade 6 and the action of the baffle plate 8 is used. In the lower agglomeration region 4, even if a guide plate is provided, it is not possible to prevent the influence of the circumferential swirling flow generated by the stirring blades, and therefore a good circulation flow cannot be formed. It became difficult to obtain stable centripetal flow and downflow, and this hindered the separation due to the inertial force of the floc floc group. In addition, a density flow (details will be described later) is generated due to a change in the concentration of the flocculation flocs as a slurry, and it is extremely complicated due to the interference between the horizontal swirl flow generated by the rotation of the stirring blade 6 and the vertical circulation flow. There was a problem that such a flow occurs. Particularly in the upper part of the lower agglomeration region 4, which is directly below the porous member 3, a density flow is likely to occur and the flow becomes more complicated. Therefore, it has been a cause of disturbing the horizontal flow (centripetal flow), which is important for separation due to the inertial force of the floc floc group.

Therefore, in the portion directly below the porous member 3, which is important for the separation of the inertial force of the floc, the horizontal flow (centripetal flow) is generated.
There is a problem that the drawing flow (downflow) in the central portion formed by the rotation of the stirring blade 6 is disturbed, a sufficient separation action cannot be obtained, and the solid-liquid separation efficiency deteriorates. Further, depending on the properties of the generated floc group, the flow region of the floc group in the lower flocculation region 4 is limited, which causes a problem that the entire lower flocculation region 4 cannot be efficiently used for the flocculation reaction and separation operation. It was

The particle interface formed in the upper part of the lower agglomeration region 4 will now be described. The mixed liquid which circulates in the lower agglomeration region 4 while forming agglomerate flocs is usually circulated in the vicinity of the porous member 3. A particle (floc) interface is formed by the balance of the flow velocity of the particles and the sedimentation velocity of the particles (aggregated flocs), but depending on the properties of the particles (aggregated flocs) formed in the mixed liquid, it is not near the porous member 3 ( Since the particle interface is formed below (or above), there are the following problems. If a particle interface is formed above the porous member 3, solid-liquid separation will be hindered, and flocs of coagulation will flow out together with the treated water, and the quality of the treated water will deteriorate. If the particle interface is formed considerably below the porous member 3, the above problem does not occur, but particularly when the treatment is performed using a coagulant, the space where the coagulation reaction is performed in the lower coagulation region 4 (effective (Volume) is reduced, and sufficient floc formation is not performed. In order to avoid or prevent the above situations, the amount of inflow water, the amount of coagulant added, the stirring strength, etc. must be adjusted according to the properties of the admixture and the position of the particle interface. It was getting complicated.

Next, the generation of a density flow due to a change in the concentration of the flocculation floc group as a slurry will be described. As described above, depending on the concentration of particles (coagulation flocs) in the circulating flow formed in the lower flocculation zone 4, A particle (flock) interface is formed, but the particle concentration becomes extremely low above this interface (clarification). Therefore, in order to withstand this rapid change in particle concentration, a flow caused by the difference in particle concentration occurs in addition to the circulation flow formed in the lower aggregation region 4. Such a flow is called a so-called density flow, and this density flow disturbs the particle interface formed in the lower agglomeration region 4 and a good circulation flow, but this density flow can be eliminated by operation adjustment or the like. Therefore, there is a problem that solid-liquid separation cannot be performed by a good and stable inertial force.

The present invention has been made in order to solve the above problems, and clearly separates the vertical flow of the water to be treated (mixed liquid) in the lower circulation region (lower coagulation region) and stabilizes it. It is an object of the present invention to provide a forced circulation type separation device that can be formed by reducing the influence of turbulent flow such as density flow and can obtain a smooth circulating flow over the entire lower circulation region.

Further, according to the present invention, in the vicinity of the porous member which divides the lower circulation region and the upper fining region, a horizontal centripetal flow of the water to be treated and a downward flow descending in the inner cylinder. Can be efficiently and stably formed, and as a result, colloidal substances and suspended substances contained in the water to be treated can be efficiently separated in a short time, and high-quality clear water can be obtained. An object is to provide a forced circulation type separation device that can be obtained.

Further, according to the present invention, the particle interface can be controlled to a fixed position near the lower surface of the porous member regardless of the property of the water to be treated, whereby the entire lower circulation region can be effectively utilized up and down. It is an object of the present invention to provide a forced circulation type separation device that can be used.

Furthermore, according to the present invention, even if the mixed liquid in which the water to be treated and the coagulant are mixed, it is introduced into the lower coagulation zone, and the colloidal substance or the suspension is dispersed in the entire lower coagulation zone. An object of the present invention is to obtain a forced circulation type separation device capable of positively and efficiently aggregating substances and forming a floc group having a large sedimentation rate.

A further object of the present invention is to provide a forced circulation type separation device which can reduce running costs such as electricity bills and can significantly reduce maintenance work.

[0015]

Means for Solving the Problems] forced circulation separator according to a first aspect of the present invention, a lower circulation zone having a raw water introduction <br/> means to introduce treated water, said lower circulation zone communicates with, provided with an upper refining zone having a treated water deriving means for deriving treated water, wherein provided a porous member between the lower circulation zone and the upper clarification zone, the said lower circular region both end openings An inner cylinder of the inner cylinder is provided , and a downward flow is formed in the inner cylinder to form a lower part.
It is characterized in that a circulation flow forming means for forming a circulation flow is provided in the circulation region .

The raw water introducing means of the forced circulation type separating apparatus according to the second aspect of the present invention is characterized by having an opening located in the inner cylinder.

In the forced circulation type separation device according to the third aspect of the present invention, two sheets are provided on the inner wall surface of the lower circulation area for rectifying the upward flow formed between the inner wall of the lower circulation area and the outer wall of the inner cylinder. It is characterized in that the above guide plate is provided.

The forced circulation separator according to the fourth aspect of the present invention includes a lower aggregation region with a miscible liquid introduction means to introduce a liquid mixture of the water to be treated and flocculant are mixed, the lower portion agglomeration zone communicating, and provided with an upper refining zone having a treated water deriving means for deriving treated water, the lower circulation zone and an upper
The porous member is provided between the refining zone, the lower aggregation region is
Only set the inner cylinder of both end openings, in the inner cylinder, downward flow into the inner cylinder
Flow type that forms a circulation flow in the lower circulation region
It is characterized in that a means for forming is provided .

In the forced circulation type separation apparatus according to the invention of claim 5, the admixture introducing means in the invention of claim 4 is provided with an opening located in the inner cylinder.

The forced circulation separator according to the invention of claim 6 is formed on the inner wall surface of the lower aggregation region in the invention of claim 4 or 5 between the inner wall of the lower aggregation region and the inner wall of the inner cylinder. Two or more guide plates are provided to rectify the upward flow.

According to the seventh aspect of the invention, in the forced circulation type separation device, the circulation flow forming means in any one of the first to sixth aspects is a shaft provided with one or more stirring blades. It is composed of a flow-type stirring blade or a jet device for jetting a water flow.

According to the eighth aspect of the present invention, there is provided a forced circulation type separation device for rectifying the flow formed by the circulation flow forming means on the inner wall surface of the inner cylinder according to any one of the first to sixth aspects. For this purpose, two or more straightening vanes are provided.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. Embodiment 1. 1A is a schematic sectional view showing a solid-liquid separation tank according to Embodiment 1 of the present invention, and FIG. 1B is FIG.
FIG. 1A is a plan view and FIG. 1C is a schematic cross-sectional view showing the operating state of FIG. 1A. The same components as those in FIG. 11 are designated by the same reference numerals and duplicate description will be omitted. In FIG. 1, 11
Is an inner cylinder arranged in the lower circulation region 4 in the solid-liquid separation tank 1, and the inner cylinder 11 is composed of a cylindrical draft tube having open upper and lower ends, and the inner bottom portion of the solid-liquid separation tank 1 and the porous member. 3, and a stirring blade (circulating flow forming means) 6 is arranged in the inner cylinder 11 thereof. Therefore, the inner cylinder 11 surrounds the stirring blade 6 in a rotation-allowed state.

In this way, the inner cylinder 11 is provided in the lower circulation region 4.
When the stirring blade 6 is rotated, the inside of the inner cylinder 11 serves as the downward flow passage 12, and the upward flow passage 13 is provided between the inner cylinder 11 and the inner peripheral wall surface of the lower circulation region 4. Are formed. In the first embodiment, the raw water introducing means 2 is connected to the upper part of the lower circulation region 4 in the solid-liquid separation tank 1, and the inner peripheral wall surface of the lower circulation region 4 includes the inner peripheral wall surface and the inner wall surface. Two guide plates 8 for rectifying the upward flow rising in the upward flow path 13 between the outer peripheral wall surface of the cylinder 11 are provided at symmetrical positions.

In the forced circulation type separation device according to the first embodiment having the above-described structure, the downward flow velocity in the inner cylinder 11, the lower end surface of the inner cylinder 11 and the bottom surface of the lower circulation region 4 (solid-liquid separation tank 1 Between the outer peripheral surface of the inner cylinder 11 and the inner peripheral surface of the solid-liquid separation tank 1 (upward flow path 13). If the rising flow velocities are substantially equal to each other, the flow state in the lower circulation region 4 can be made smoother, and it is also effective for inertial force separation near the lower surface of the porous member 3. In particular, when the mixed solution is introduced to form floc flocs, the flocculation reaction can be efficiently and stably performed.

Therefore, the cross-sectional area of the inner cylinder 11 (the downward flow passage 12
Cross-sectional area of) = S ₁ , cross-sectional area of the upward flow path 13 formed between the inner peripheral surface of the solid-liquid separation tank 1 and the outer peripheral surface of the inner cylinder 11 =
S ₂ , the peripheral area of the space formed between the lower end surface of the inner cylinder 11 and the bottom surface of the lower circulation region 4 (the inner bottom surface of the solid-liquid separation tank 1) (the “peripheral length of the inner cylinder 11” and the “inner cylinder”). 11 is the value obtained by multiplying the distance between the lower end surface and the bottom surface of the lower circulation region 4) = S _3, and S ₁
It is desirable that S ₂ and S ₃ be set to have substantially the same cross-sectional area. Note that the cross-sectional areas are not limited to these unless the areas are extremely different.

On the other hand, if the distance between the lower surface of the porous member 3 and the upper end surface of the inner cylinder 11 is extremely short, the upward flow violently collides with the porous member 3 and interferes with solid-liquid separation. To have. As a measure of the interval, in order to make the flow velocity between the lower surface of the porous member 3 and the upper end surface of the inner cylinder 11 gentler than the average flow velocity in the lower circulation region 4, the lower circulation region 4 It is desirable to make it longer than the space between the bottom surface of the inner cylinder 11 and the lower end surface of the inner cylinder 11, but the invention is not limited to this.

Next, the operation will be described. Solid-liquid separation tank 1
The stirring blade 6 is rotated in a state where the untreated water containing the colloidal substance and / or the suspended substance (mixed liquid in which the untreated water and the coagulant are mixed) is introduced and filled from the raw water introducing means 2 into the inside. When driven, a downward flow of the water to be treated (mixed liquid) is generated from the upper end opening of the inner cylinder 11 to the lower end through the inner cylinder 11. Then, the water to be treated that has reached the lower end of the inner cylinder 11 is turned into a horizontal flow (radial flow) between the lower end of the inner cylinder 11 and the bottom of the lower circulation region 4, and then inside the lower circulation region 4. It advects to the space (upward flow path) 13 formed between the peripheral wall surface and the outer peripheral wall surface of the inner cylinder 11 and rises.

Here, the water to be treated which has turned into a radial flow from the lower end of the inner cylinder 11 as described above rises vertically between the inner peripheral wall surface of the lower circulation region 4 and the outer peripheral wall surface of the inner cylinder 11. It flows and is rectified by the guide plate 8. Then, the water to be treated that has reached the upper part of the lower circulation region 4 is affected by the downward flow formed in the inner cylinder 11, and flows in the horizontal direction between the upper end of the inner cylinder 11 and the porous member 3 (the centripetal direction). Flow), advancing into the inner cylinder 11 and descending.

At this time, as shown in FIG. 1 (c), the inner cylinder 11
A particle interface is formed from the vicinity of the upper end to the vicinity of the porous member 3 by the sedimentation speed of particles (flocs) and the flow velocity of the circulation flow. Then, the water to be treated (mixed solution) in the vicinity of the porous member 3, the upper clarifying region Kiyoshi Kiyoshi water treated water in the same amount flowing in the lower circulation zone 4 passes through the water-passing holes of the porous member 3 5, the particle (flock) group is affected by the horizontal centripetal flow and the downward flow downward in the inner cylinder 11 and descends in the inner cylinder 11 together with the circulation flow, and becomes solid (particle group). -Liquid ( clear water)
To be separated. Particles (flocks) are separated and the porous member 3
The clarified water which passes through the water passage holes increase the upper fining zone 5 is discharged from the treated water deriving means 9 as treated water outside the system.

According to the first embodiment described above, in the lower circulation region 4 in the solid-liquid separation tank 1, the inner cylinder 11 having the upper and lower ends opened is arranged so as to surround the stirring blade 6, The particle interface can be controlled from the vicinity of the upper end of the inner cylinder 11 to an appropriate position near the porous member 3, and therefore, the entire lower circulation region 4 can be effectively used for solid-liquid separation and the property of the water to be treated can be improved. Nevertheless, there is an effect that the particle interface can be made constant. In particular, when the mixed solution is introduced, the inside of the lower circulation region 4 can be maximally used as the aggregation reaction space.

Since the inner cylinder 11 is provided as described above, a downward flow is generated in the inner cylinder 11, and a horizontal radial flow is generated between the lower end of the inner cylinder 11 and the bottom of the lower circulation region 4. It is possible to clearly distinguish the upward flow between the inner peripheral wall surface of the lower circulation region 4 and the outer peripheral wall surface of the inner cylinder 11, and the horizontal centripetal flow between the upper end of the inner cylinder 11 and the porous member 3. Since a stable circulation flow can be formed, there is an effect that solid-liquid separation by inertial force can be efficiently and accurately performed near the lower surface of the porous member 3.

That is, by the inner cylinder 11, the inner cylinder 11
A downward flow in the inner cylinder, a radial flow from the lower end of the inner cylinder 11, an upward flow between the solid-liquid separation tank 1 and the inner cylinder 11, and a centripetal flow between the upper end of the inner cylinder 11 and the porous member 3. A clearly separated forced circulation flow can be obtained. Therefore, especially in the vicinity of the porous member 3 in the lower circulation region 4, a turbulent flow with less turbulence is generated in the inner cylinder 11
It is sucked in smoothly. Therefore, in the vicinity of the lower surface of the porous member 3, the particle (flock) group is strongly affected by the horizontal centripetal flow and the downward flow that is the flow sucked into the inner cylinder 11, and therefore, is efficiently and stably stabilized. Then, solid-liquid separation can be performed by inertial force.

Embodiment 2. 2 (a) is a schematic sectional view showing a solid-liquid separation tank according to Embodiment 2 of the present invention, FIG.
2B is a plan view of FIG. 2A, and FIG.
The same components as those in (b) and (c) will be assigned the same reference numerals and overlapping description will be omitted. In FIG. 2, reference numeral 20 denotes a raw water introducing means for introducing into the inner cylinder 11 water to be treated containing colloidal substances and / or suspended substances or a mixed liquid in which the water to be treated and the flocculant are mixed. Therefore, this raw water introducing means 20 has an opening located in the inner cylinder 11.

Reference numeral 14 is a sludge take-out means for taking out sludge from the inner lower part of the solid-liquid separation tank 1, and 15 is a sedimentation prevention plate (flock sedimentation prevention) provided all around the bottom corner of the solid-liquid separation tank 1. Means). The anti-sink plate 15 is used for the inner cylinder 1
The water to be treated which has turned into a radiant flow from the lower end of 1 is smoothly guided to an ascending flow along the inner peripheral surface of the solid-liquid separation tank 1, and the floc particles contained in the water to be treated have solid-liquid separation tank 1 To prevent it from depositing in the corners of the bottom of the tank. Such an anti-sink plate 1
5 is not limited to a taper shape as shown in the figure, but may be a concave curved surface in cross section. In this Embodiment 2, the guide plate 8 is shown in FIG.
As shown in FIG. 4, four sheets are provided on the inner wall surface of the lower circulation region 4 at intervals of 90 degrees.

As described above, in the second embodiment, since the tip of the raw water introducing means 2 is opened in the inner cylinder 11, the water to be treated or the mixed liquid is supplied in the inner cylinder 11 and the lower circulation region 4.
The effect that it can be reliably introduced into the upper clarification zone 5 and therefore the water to be treated or the mixed solution can be prevented from short-circuiting with the upper clarification zone 5 or flowing out to the upper clarification zone 5 without formation of sufficient floc flocs. There is. Further, since the sedimentation prevention plate 15 is provided in the corner portion of the bottom of the solid-liquid separation tank 1, the water to be treated which has turned into the radial flow from the lower end of the inner cylinder 11 is directed upward.
It can be advected smoothly toward. Therefore, turbulent flow of the water to be treated does not occur at the corner of the bottom of the solid-liquid separation tank 1, and no flocculation flocs are deposited, and a smooth circulation flow is formed over the entire lower circulation region 4. It can be maintained, and is also effective for separating particles (flocks) by the inertial force in the vicinity of the porous member 3. Furthermore, the four guide plates 8 can smoothly and efficiently generate an upward flow between the inner peripheral wall surface of the lower circulation region 4 and the outer peripheral wall surface of the inner cylinder 11.

Embodiment 3. FIG. 3 is a schematic sectional view showing a solid-liquid separation device according to a third embodiment of the present invention. The same components as those in FIGS. In the third embodiment, the guide plate 8 shown in FIG.
It has a configuration in which is removed. Even in this case, the inner cylinder 11 causes a downward flow in the inner cylinder 11, a radial flow at the bottom of the lower circulation region 4, and an upward flow between the solid-liquid separation tank 1 and the inner cylinder 11. There is no change in that a series of forced circulation flows in which the centripetal flow between the upper end of the inner cylinder 11 and the porous member 3 is clearly separated are formed. Therefore, similar to the case of the first embodiment, It is possible to form and maintain a smooth circulating flow over the entire lower circulation region 4, and it is also effective for separating particles (flocks) by the inertial force in the vicinity of the porous member 3.

Fourth Embodiment 4 is a schematic sectional view showing a solid-liquid separation tank according to Embodiment 4 of the present invention. The same components as those in FIGS. In FIG. 4, a plurality of 16 are provided on the inner peripheral wall surface of the inner cylinder 11 and are located above the stirring blades 6 (9 in the figure).
It is a straightening plate of 4 sheets at intervals of 0 degree. The current plate 16 is
The swirling flow in the substantially horizontal direction generated by the rotation of the stirring blade 6 in the inner cylinder 11 is rectified into a vertical flow, the upper end of which is lower than the upper end of the inner cylinder 11 and the lower end of the stirring blade 6. It is installed near the upper part. The length and installation position of the straightening plate 16 in the horizontal direction and the vertical direction are arbitrary, and may be appropriately changed depending on the stirring condition and the processing condition.

By providing the straightening plate 16 in the inner cylinder 11 in this way, the circumferential swirling flow generated by the rotational driving of the stirring blade 6 can be converted into a vertical flow, and the inner cylinder 11 has The vertical downward flow can be smoothly and efficiently formed, and the vertical upward flow can be smoothly and efficiently formed by the guide plate 8 between the inner peripheral wall surface of the lower circulation region 4 and the outer peripheral wall surface of the inner cylinder 11, Therefore, there is an effect that the ideal forced circulation flow can be formed more efficiently in the lower circulation region 4.

Embodiment 5. FIG. 5 is a schematic sectional view showing a solid-liquid separation tank according to Embodiment 5 of the present invention. The same components as those in FIGS. 1 to 4 are designated by the same reference numerals to omit redundant description. In the fourth embodiment, the guide plate 8 on the inner circumference of the solid-liquid separation tank 1 and the straightening plate 16 in the inner cylinder 11 are used together, but in the fifth embodiment, the guide plate 8 is removed. It is configured. Even in this case, since the swirling flow in the circumferential direction generated by the rotation of the stirring blade 6 can be converted into the vertical flow by the flow straightening plate 16, the vertical downward flow is smoothly and efficiently formed in the inner cylinder 11. Therefore, the same action and effect as in the case of the fourth embodiment can be obtained except the action and effect by the guide plate 8.

Modifications. 6 to 9 show the first embodiment described above.
FIG. 6 is a schematic cross-sectional view showing a modified example of the solid-liquid separation tank according to FIGS. 5 to 5, and a circular tank is applied as the solid-liquid separation tank 1 in the first embodiment (FIG. 1) to the fifth embodiment (FIG. 5). However, in this modified example, the solid-liquid separation tank 1 has a rectangular tubular structure, and the solid-liquid separation tank 1 is provided with deposition preventing plates 15a at the corners inside the bottom of the tank. 6 is the same as FIG. 3, FIG. 7 is FIG. 2, and FIG. 8 is FIG.
9 is the same as FIG. 4, respectively, and the same components are assigned the same reference numerals and explanations thereof are omitted. As described above, even when the solid-liquid separation tank 1 has a rectangular tubular tank configuration, the same operational effect as in the above-described first to fifth embodiments can be obtained.

Embodiment 7. The stirring blade (circulation flow forming means) 6 applied in each of the above-described embodiments and modifications basically includes one or more stirring blades that form a downward flow in the inner cylinder 11. Although an axial-flow type stirring blade is desirable, it may be jetted downward in the inner cylinder 11 by using a jetting device (for example, a circulator (not shown)) that jets a water stream. In particular, unless a high-strength agitator that destroys suspended solids (particles, flocs) contained in the water to be treated or aggregate flocs formed in the lower aggregation region 4, the water flow is downward in the inner cylinder 11. It is not limited to this as long as it can be formed. Further, as shown in FIG. 10, the inner cylinder 11 is not limited to a straight tube having the same diameter throughout its length, but is a tapered tube having a gradually decreasing diameter on the upper end opening side so that a downward flow can be more easily formed near the lower surface of the porous member 3. It may be provided, as long as the required upper and lower ends are open and a downward flow can be formed.

Further, when the water to be treated is introduced into the lower circulation region 4, it aggregates in the lower circulation region 4 (inside the inner cylinder 11 is effective) depending on the properties of the water to be treated and the required treatment water quality. Agents may be added. As a result, it is possible to obtain the same operational effect as when the mixed liquid is introduced, and it is possible to more efficiently and stably perform solid-liquid separation. In addition, even in the case described above or in the case of introducing the mixed liquid, in order to perform the solid-liquid separation more efficiently and stably in a short time, the inside of the lower circulation region (the lower aggregation region) 4 (the inside of the inner cylinder 11 is effective), In order to form a larger floc, flocculant may be added, or fine inorganic substance such as fine sand may be added as a weight material in order to make the floc to be formed into a weight so as to easily settle. You may add as.

[0044]

As described above, according to the present invention, the following excellent effects are obtained by providing the inner cylinder of the both ends opening surrounding the circulation forming means in the lower circulation region. 1. Mainly in the lower circulation region, the flow in the vertical direction can be clearly divided and stably formed, and the influence of the density flow that disturbs the particle interface formed in the vicinity of the porous member can be reduced, so that it can be spread over the entire lower circulation region. And a smooth circulating flow and particle interface can be formed. 2. Since a smooth circulation flow can be obtained in the entire lower circulation region, a horizontal flow (centripetal flow) and a flow toward the inner cylinder (downflow) are efficiently and stably formed near the porous member, Therefore, an inertial force in a horizontal direction or a downward direction can be applied to the particle (flock) group, and thus the particle (flock) group can be efficiently separated from the water to be treated in a short time. 3. Since fine particles (flocs) can also be efficiently separated in a short time, clear water of good water quality can be stably obtained. Further, by adding a gravity material such as fine sand to the water to be treated in addition to the flocculant, more efficient solid-liquid separation can be performed. 4. Further, in the forced circulation type separation device according to the present invention, solid-liquid separation by inertial force can be performed efficiently and stably, so that not only a settling tank requiring a large site is not required, but also the entire device can be made compact. The construction cost can be reduced. 5. Further, the forced circulation type separation device according to the present invention,
Since there are few machines to drive, running costs such as electricity bills can be reduced, and work such as maintenance can be greatly reduced. 6. By providing the inner cylinder in the lower circulation area, the particle interface can be controlled to an appropriate position near the upper end of the inner cylinder, and therefore the position of the particle interface can be kept constant regardless of the properties of the water to be treated. In addition, since the vertical and horizontal flows can be clearly separated, a smooth circulation flow can be formed and maintained in the lower circulation region vertically. 7. Since a smooth circulation flow can be obtained in the lower circulation region, when a mixture liquid in which the coagulant is mixed is introduced into the lower aggregation region, the aggregation reaction that forms floc flocs can be efficiently performed in the entire lower aggregation region. it can. 8. Therefore, even if the fluctuation amount of water and water of the water to be treated, in order to actively solid-liquid separation by utilizing the inertial force without subject to separation by gravity precipitation, sufficiently stable and good quality refining <br /> You can get water. 9. Further, in the usual coagulation-sedimentation treatment, it was essential to form a coagulation floc having a large sedimentation velocity in order to cause gravity sedimentation in the coagulation sedimentation tank. Since solid-liquid separation is performed by using force, it is not essential to form aggregated flocs with a high sedimentation rate, and it is also possible to separate colloidal substances and suspended substances without adding a flocculant. is there.

A circulation flow effective for inertial force separation cannot be sufficiently formed, and it is difficult to control the formation position of the particle interface, as compared with a conventional flocculation / separation device (FIG. 11 of the present applicant). In particular, even if the inflow rate of the mixed solution is doubled as compared with the conventional method, the retention time in the lower coagulation region is 3 to 4 times that of the conventional method.
In the device according to the present invention with respect to min, 1.5 to 3 mi
n, the treated water turbidity, which is an index of water quality,
In the present invention, it was 1 to 3 ppm as compared with the conventional value of 3 to 6 ppm, and a clear effect could be obtained.

[Brief description of drawings]

1A is a schematic cross-sectional view showing a solid-liquid separation tank according to Embodiment 1 of the present invention, FIG. 1B is a plan view of FIG. 1A, and FIG. It is a schematic sectional drawing which shows the driving | running state of 1 (a).

2 (a) is a schematic sectional view showing a solid-liquid separation tank according to Embodiment 2 of the present invention, and FIG. 2 (b) is a plan view of FIG. 2 (a).

FIG. 3 (a) is a schematic sectional view showing a solid-liquid separation tank according to Embodiment 3 of the present invention, and FIG. 3 (b) is a plan view of FIG. 3 (a).

4 (a) is a schematic sectional view showing a solid-liquid separation tank according to Embodiment 4 of the present invention, and FIG. 4 (b) is a plan view of FIG. 4 (a).

5 (a) is a schematic sectional view showing a solid-liquid separation tank according to a fifth embodiment of the present invention, and FIG. 5 (b) is a plan view of FIG. 5 (a).

6 (a) is a schematic sectional view showing a modified example of the solid-liquid separation device according to each embodiment of the present invention, and FIG. 6 (b) is a plan view of FIG. 6 (a).

7 (a) is a schematic sectional view showing a modified example of the solid-liquid separation device according to each embodiment of the present invention, and FIG. 7 (b) is a plan view of FIG. 7 (a).

8 (a) is a schematic sectional view showing a modified example of the solid-liquid separation device according to each embodiment of the present invention, and FIG. 8 (b) is a plan view of FIG. 8 (a).

9 (a) is a schematic sectional view showing a modified example of the solid-liquid separation device according to each embodiment of the present invention, and FIG. 9 (b) is a plan view of FIG. 9 (a).

FIG. 10 (a) is a plan view showing a modified example of the inner cylinder applied to the solid-liquid separation device according to each embodiment of the present invention,
FIG. 10B is a side view of FIG. 10A.

FIG. 11 is a schematic sectional view of a flocculation / separation device according to a conventional example.

[Explanation of symbols]

1 Solid-Liquid Separation Tank 2 Raw Water Introducing Means 3 Porous Member 4 Lower Circulation Region (Lower Coagulation Region) 5 Upper Clarifying Region 6 Stirring Blade (Circulating Flow Forming Means) 8 Guide Plate 9 Treated Water Deriving Means 11 Inner Cylinder 12 Downward Flow Path 13 upward flow path 14 sludge removal means 15 sedimentation prevention means 16 straightening plate (rectifying means) 20 raw water introducing means

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kaoru Hirota 3-6-18 Shibaura, Minato-ku, Tokyo Inside Nishihara Institute of Environmental Health (56) References JP-A-51-142161 (JP, A) Kai 49-3460 (JP, A) JP 54-71470 (JP, A) JP 51-40027 (JP, B1) JP 48-23579 (JP, B1) JP 49-17340 (JP) JP, Y1) Actual public 51-47630 (JP, Y1) Actual public 31-18748 (JP, Y1) Actual public 56-37767 (JP, Y1) (58) Fields investigated (Int.Cl. ⁷ , DB name) B01D 21/00-21/34

Claims (8)

(57) [Claims] A lower circulation zone for the raw water introduction means to introduce treated water is provided 1. A containing colloidal substances and / or suspended matter, communicates with the said lower circulation zone, deriving treated water an upper refining region treated water deriving means is provided which, together with a plurality of water flow holes, and the porous member provided between the lower circulation zone and the upper clarified zone was found provided in the lower circulation region ends And an inner cylinder that opens , and a lower flow is formed in the inner cylinder to form a downward flow.
A forced circulation separation device comprising: a circulation flow forming means for forming a circulation flow in the circulation region . 2. The forced circulation type separation apparatus according to claim 1, wherein the raw water introducing means has an opening located in the inner cylinder. 3. The inner wall surface of the lower circulation region is provided with two or more guide plates for rectifying the upward flow formed between the inner wall of the lower circulation region and the outer wall of the inner cylinder. The forced circulation type separation device according to claim 1 or 2. 4. A lower aggregated region immiscible liquid introduction means is kicked set of colloidal substances and / or treated water containing suspended matter and coagulant introduces a mixture solution miscible, said lower aggregation communicated with the frequency, an upper refining zone where the processing <br/> water deriving means for deriving treated water provided, which has a plurality of water flow holes is provided between the lower flocculation zone and the upper clarified zone and a porous member, a cylindrical inner ends are found provided on the lower aggregation region is opened, is provided in the inner cylinder, the bottom to form a downward flow into the inner cylinder
A forced circulation separation device comprising: a circulation flow forming means for forming a circulation flow in the circulation region . 5. The forced circulation separator according to claim 4, wherein the admixture introducing means has an opening located in the inner cylinder. 6. The inner wall surface of the lower aggregation region is provided with two or more guide plates for rectifying the upward flow formed between the inner wall of the lower aggregation region and the inner wall of the inner cylinder. The forced circulation type separation device according to claim 4 or 5. 7. The circulating flow forming means is an axial flow type stirring blade having one or more stirring blades or a jet device for jetting a water flow.
The forced circulation type separation device according to any one of 1. 8. The inner wall surface of the inner cylinder is provided with two or more straightening vanes for straightening the flow formed by the circulation flow forming means. The forced circulation type separator according to any one of 1.