JP7209514B2 - Sedimentation pond - Google Patents

Description

The present invention relates to a sedimentation basin equipped with an upflow-type inclined sedimentation device.

Conventionally, in sedimentation tanks, baffle plates are arranged at regular intervals in the direction orthogonal to the water flow so that the raw water flows evenly into the collection trough between the sedimentation device and the collection trough. It is
For example, in the upward-flow tilting sedimentation tank described in Patent Document 1, the supernatant layer of the upward-flow tilting device is kept constant by baffles in the longitudinal direction and baffles in the width direction for each pitch of the tilting pipe. separated by intervals. As a result, when relatively high-temperature raw water is mixed in the sedimentation tank, the high-temperature raw water is pushed up by the low-temperature raw water and rises at high speed in the inclined pipe or between the inclined plates of the inclination device. This high-speed raw water prevents raw water exceeding the water intake capacity of the water intake trough from rising in the inclined pipe or between the inclined plates because the skim layer is partitioned by the baffle plate for each pitch. Therefore, it is said that the flocs in the raw water can be sedimented and separated before reaching the supernatant layer.

JP-A-62-298409

By the way, in the sedimentation tank described in Patent Document 1, when raw water flows into the space between the inclined pipes and inclined plates of the tilting device, more raw water flows into the upstream region than the downstream region on the inflow side of the tilting device. While raw water flows in, there is a problem that a short-circuit flow, which is a high-speed upward flow, occurs in each inclined pipe in the upstream region because a sufficient flow rate of raw water does not flow into the downstream region.

Moreover, the raw water flowing into the sedimentation tank is affected by the density flow due to the water temperature, etc., and the flow velocity and concentration fluctuate rather than being constant. Even if baffle plates are installed evenly in the upstream area, the flow is obstructed by the baffle plate in the upstream area, polluting the supernatant layer, causing carryover, short-circuit flow, or downward flow. There arises a problem that the treatment efficiency is not uniform throughout, such as a decrease in the treatment of raw water in the region. The carryover and short-circuit flow that occurred in the upstream region could not sufficiently settle the flocs, and therefore could not prevent the raw water containing the flocs from flowing into the collection trough.

In view of such problems, the present invention suppresses the unevenness of the flow rate of raw water flowing into the sedimentation device, suppresses the flow of flocs that are not sedimented due to carryover or short-circuit flow, and improves the treatment efficiency. The purpose is to provide a sedimentation pond that can

In order to achieve the above object, the sedimentation basin according to the present invention comprises a sedimentation device that is provided in the sedimentation basin and allows raw water to pass through to settle flocs, and a sedimentation device that is provided on the outflow side of the sedimentation device to treat the raw water. It is characterized by comprising a water collection trough for taking in treated water, and a plurality of baffles arranged between the sedimentation device and the water collection trough, movable and adjustable in mutual spacing.
According to the present invention, even if the flow velocity and concentration of the raw water change, by moving the baffle arranged between the sedimentation device and the water collection trough accordingly to adjust the mutual interval, the raw water can be efficiently sedimented and separated into clarified water and sediment.

Moreover, it is preferable that the baffle plate is divided into a plurality of pieces.
A baffle can also be installed in an existing sedimentation tank by separately arranging the baffle halves, which are divided into a plurality of baffles, between the sedimentation device and the water collection trough.

Alternatively, the baffle may be suspended from a substrate disposed above the water collection trough.
By suspending the baffle from the substrate, the baffle can be easily installed and removed even in existing sedimentation tanks.

Also, the baffle plate may be movable along a guide member disposed above the water collection trough.
Even if the flow velocity or concentration of raw water changes, the distance between the baffle plates can be freely adjusted by moving the baffle plates along the guide member between the sedimentation device and the water collection trough. It can be set and the treatment efficiency of raw water can be improved.

According to the sedimentation tank according to the present invention, since the baffle plate is movably installed between the sedimentation device and the water collection trough, the flow rate of raw water flowing into the sedimentation device, the required flow rate of treated water to be taken out, and changes in concentration By adjusting the arrangement intervals of the baffle plates accordingly, the raw water treatment efficiency can be improved. For example, in the upstream region of the sedimentation device where the flow velocity and flow rate are high, the baffle plates are arranged at narrow intervals, and in the downstream region where the flow velocity and flow rate are low, the baffle plates are arranged at wider intervals to prevent short circuits. It is possible to prevent sediment from settling and entering the water collection trough due to flow or carryover, thereby improving the treatment of raw water.
Also, when cleaning the sedimentation device, the water collecting trough, etc., cleaning is facilitated by moving the baffle to one side.

1 is a side cross-sectional view of a main part of a sedimentation tank according to a first embodiment of the present invention; FIG. Figure 2 is a front view of the tilt settling device in Figure 1; Fig. 2 is a side view of the tilt settling device; 1 is a plan view of a tilt settling device; FIG. It shows the inclined sedimentation apparatus of the sedimentation tank by 2nd embodiment, (a) is a front view, (b) is a C part enlarged view. Fig. 2 is a side view of the tilt settling device; 1 is a plan view of a tilt settling device; FIG.

A sedimentation basin according to an embodiment of the present invention will be described below with reference to the accompanying drawings.
1 to 4 show a sedimentation tank 1 according to a first embodiment of the invention.
In the sedimentation basin 1 shown in FIGS. 1 and 2, an inclined sedimentation device 3 is installed as a sedimentation device on the downstream side of a straightening wall 2 having a large number of inlet holes for allowing raw water to pass through. The inclined sedimentation device 3 has, for example, a large number of inclined tubes 4 (or inclined plates) arranged vertically and horizontally in close contact with each other, and each of the inclined tubes (or between the inclined plates) 4 forms a separate flow path for raw water, They are arranged in a posture in which the upper part is inclined toward the straightening wall 2 side with respect to the vertical direction. In the inclined sedimentation apparatus 3, the inclined pipes (or between inclined plates) 4 may be arranged so that the upper part thereof is separated from the straightening wall 2 with respect to the vertical direction, or may be arranged in the vertical direction. may be

The inclined sedimentation device 3 is formed, for example, in a substantially rectangular parallelepiped shape, and has a length L with the feed direction of raw water being the vertical direction (longitudinal direction) and a length W being the width direction. The lower surface 3a of the inclined sedimentation device 3 is the raw water inlet, and the upper surface 3b is the outlet. Raw water flowing into each inclined pipe 4 from the lower surface 3a side separates and agglomerates the flocs in the inclined pipe 4, causing them to fall downward as sediments, and the remaining supernatant water (clear water) flows out from the upper surface 3b.
In the inclined sedimentation device 3 shown in FIG. 1, the lower surface 3a is divided into an upstream region A and a downstream region B in the flow direction of the raw water. A relatively large amount of raw water flows into the upstream area A at a high speed, and a relatively small amount of raw water flows into the downstream area B at a low speed.

A skim layer 5 is provided in the space on the upper surface 3b side of the inclined sedimentation device 3, and a plurality of baffle plates 6 are arranged in the skim layer 5 at predetermined intervals in the longitudinal direction (length L direction). The baffle plate 6 is movable in the longitudinal direction by a moving device 10 as will be described later. A water collecting trough 7 extends longitudinally above the baffle plate 6 . For example, one or a plurality of water collecting troughs 7 are arranged at predetermined intervals in the width direction, and the skimmed water that has flowed over the upper end of the side portion 7b higher than the water surface and has been taken is collected and sent to the next process. I have to.

Next, the moving device 10 for the baffle plate 6 will be described with reference to FIGS. 2 to 4. FIG.
As shown in FIG. 2, the baffle plate 6 is arranged between the inclined sedimentation device 3 and the water collection trough 7, and is divided into a plurality of pieces, for example two pieces. The baffle plate 6 is formed of a pair of baffle plate half portions 6A and 6B, and the baffle plate half portions 6A and 6B are each formed in a substantially L-shaped plate shape. The baffle plate 6 is arranged so that the space between the inclined sedimentation device 3 and the water collecting trough 7 is covered by the baffle plate halves 6A and 6B.
A base material 11 is disposed on the upper part of the water collecting trough 7 and the baffle plate 6 in the width direction perpendicular to the water collecting trough 7 . are fixed respectively. An attachment handle 13 is detachably installed inside each moving handle 12, and the attachment handle 13 has a gripping head portion 13a and a shaft portion 13b. A shaft portion 13b of the mounting handle 13 penetrates the base member 11 and is connected to the upper portions of the baffle plate halves 6A and 6B.

As shown in FIG. 4, notches 11a extending from the end faces are formed at the positions of the mounting handles 13 on both left and right sides of the base material 11, and the shaft portions 13b of the mounting handles 13 are inserted into the notches 11a. . Each notch 11a preferably extends to the widthwise central portion of the base material 11 and cuts out. In the example shown in FIG. 4, the cutouts 11a on the left and right sides are formed on two opposing end surfaces, that is, at positions 180 degrees rotationally symmetrical, but may be formed on the same end surface.
Here, in order to attach the baffle plate halves 6A and 6B to the notch 11a of the base material 11, the baffle plate halves 6A and 6B are extended in the longitudinal direction of the base material 11 and attached to the mounting handle. The shaft portion 13b of 13 is inserted into the notch 11a. By rotating the shaft portion 13b by 90° at the innermost portion of the notch 11a, the plate surfaces of the baffle plate half portions 6A and 6B are opposed to each other in the longitudinal direction of the base material 11 as shown in FIG. be placed.

Therefore, even if the lower portions of the baffle halves 6A and 6B are larger than the gap width between the side wall of the sedimentation tank 1 and the water collection trough 7, they can be installed by rotating the shaft portion 13b by 90°. As shown in FIG. 2, the baffle plate 6 is arranged in a substantially U-shape with a slight gap in a state where the baffle plate halves 6A and 6B are attached, and the side wall of the sedimentation tank 1 and the collector. The gap between the water trough 7 and the gap between the water collecting trough 7 and the inclined settler 3 can be filled. Therefore, even if a short-circuit flow flows in through the inclined pipe 4 of the inclined sedimentation device 3, the flow can be obstructed and entry into the water collecting trough 7 can be prevented.

Next, in the base material 11, a pair of wheels 15 are installed inside the left and right mounting handles 13 and on the lower surface side. Each wheel 15 is supported by a pair of supports 17 on both sides through a shaft portion 16 , and the supports 17 are fixed to the lower surface of the base material 11 . The water collecting trough 7 has a bottom portion 7a and side portions 7b on both sides of the bottom portion 7a. At the upper end of each side portion 7b, outwardly bent flanges are formed as running surfaces 7c for the wheels 15. As shown in FIG. As shown in FIG. 3, a pair of wheels 15 are arranged in front and behind the baffle plate 6 in a side view.
In the sedimentation tank 1 according to this embodiment, the moving handle 12, the mounting handle 13, the baffle plate halves 6A and 6B, and the wheels 15 are symmetrically installed on both left and right sides with respect to the longitudinal direction center of the base material 11. there is

The water collecting trough 7 is formed to extend in the longitudinal direction, and a pair of running surfaces 7c are continuously formed in that range. Moreover, the pair of supports 17 provided on both sides of the wheel 15 extends below the running surface 7c of the water collection trough 7 and functions as a guide so that the wheel 15 does not come off the running surface 7c when running. Therefore, the baffle 6 consisting of the baffle plate halves 6A and 6B together with the base material 11 can be moved by moving the wheel 15 on the traveling surface 7c of the water collecting trough 7 while gripping the moving handle 12. can move.

The sedimentation tank 1 according to the first embodiment has the structure described above. First, the method of attaching the baffle plate 6 will be described.
In the existing sedimentation tank 1, when installing the baffle 6 between the inclined sedimentation device 3 and the water collection trough 7, the base material 11 is placed on the upper part of the water collection trough 7 installed on the upper surface 3b side of the inclined sedimentation device 3. Install. It is assumed that the substrates 11 are installed in the same number as the baffle plates 6 . When the substrate 11 is installed, the wheels 15 are placed on running surfaces 7c provided at the upper ends of the left and right side portions 7b of the water collecting trough 7, respectively.

Next, the shaft portions 13b of the attachment handles 13 are connected and fixed to the upper portions of the baffle plate halves 6A and 6B. Then, the baffle plate halves 6A and 6B are positioned in the longitudinal direction of the water collection trough 7, and the shaft portions 13b of the mounting handles 13 are inserted into the notches 11a formed in the opposite end surfaces of the substrate 11. do.
With each shaft portion 13b inserted into the deepest portion of the notch 11a, by rotating the shaft portion 13b by 90 degrees toward the water collection trough 7, the baffle plate half-split portions 6A and 6B are separated from the water collection trough 7. Between the inclined sedimentation device 3, as shown in FIG. In this state, baffle plates 6 are arranged at equal intervals in the longitudinal direction of water collection trough 7 .

Next, a method for adjusting the position of the baffle plate 6 in the sedimentation tank 1 will be described.
In the sedimentation tank 1 , raw water that has passed through the holes in the straightening wall 2 flows into the inclined sedimentation device 3 . As shown in FIG. 1, since a large amount of raw water flows into the upstream region A of the inclined sedimentation device 3, the flow velocity increases and short-circuit flow is likely to occur. inflow rate and treatment were uneven. Especially in the upstream region A, a short-circuit flow of raw water is likely to occur. Therefore, the raw water cannot be sufficiently sedimented and separated from the flocs in the inclined pipes 4 of the inclined sedimentation device 3, and the flocs are removed from the supernatant layer 5 into the water collecting trough 7. was flowing into
In this embodiment, the position of the baffle plate 6 arranged on the upper surface 3b side of the inclined sedimentation device 3 is adjusted. That is, the worker grasps the moving handles 12 on both the left and right sides and pushes the base material 11, thereby causing the wheels 15 to run on the pair of running surfaces 7c of the water collection trough 7, thereby separating the baffle plate halves 6A and 6B. can be moved integrally with respect to the inclined settling device 3 and the water collecting trough 7.

Then, as shown in FIG. 1, in the upstream area A where a large amount of raw water flows, the baffle 6 is moved to the upper surface 3b of the inclined sedimentation device 3 to arrange a plurality of baffles 6 at narrow intervals. On the other hand, in the downstream area B, the baffle plates 6 are arranged at large intervals because the inflow of raw water is small. In the upstream region A, the raw water flowing out from the inclined pipe 4 of the inclined sedimentation device 3 collides with the baffle plate 6 with a narrow interval and is impeded, so that the rise of flocs and their sediments is impeded, and a short-circuit flow occurs. can be prevented. Therefore, the flocs can be sedimented from the raw water by the inclined pipes 4 of the inclined sedimentation device 3 to separate the treated water. Therefore, it is possible to prevent flocs and their deposits from flowing into the water collecting trough 7 .

In addition, since the raw water whose inflow is blocked in the upstream area A flows into the downstream area B, the inflow amount of raw water in the downstream area B increases. Also in the downstream region B, the baffle plates 6 are moved on the upper surface 3b of the inclined sedimentation device 3 to arrange a plurality of baffle plates 6 at wider intervals. In the downstream region B, since the distance between the baffle plates 6 is large, the inflow amount and flow velocity of the raw water increase. Therefore, the flocs are separated and sedimented from the raw water by the inclined sedimentation device 3, and the treated water is discharged efficiently, so that the raw water can be treated.

The treated water that has flowed out from the upper surface 3b of the inclined sedimentation device 3 to the supernatant layer 5 crosses over the running surfaces 7c on both sides 7b of the water collection trough 7 in the area partitioned by the baffle plate 6 and passes between the wheels 15. It flows into the water collection trough 7 .
When the amount or concentration of raw water flowing into the inclined sedimentation device 3 changes, or when the amount of supernatant water taken out is adjusted, the baffle plate 6 is moved by the moving device 10 according to the change in the amount of raw water flowing. By moving the baffle plate 6, the interval between the baffle plates 6 can be further increased or decreased.
In addition, when cleaning the water collection trough 7 and the like, each baffle plate 6 can be moved and moved to one side, so that cleaning can be easily performed. The baffle plate 6 and its moving device 10 according to the present embodiment can also be employed in the newly installed sedimentation tank 1 .

As described above, according to the present embodiment, the plurality of baffle plates 6 are moved by the moving device 10 when adjusting the amount and concentration of the raw water flowing into the inclined sedimentation device 3 and the amount of supernatant water taken out. The flow rate and flow velocity of the raw water can be adjusted by narrowing or widening the gap. Therefore, it is possible to prevent a short-circuit flow and prevent floc deposits from flowing into the water collection trough 7 . In addition, in the sedimentation tank 1 shown in FIG. 1, the interval between the baffle plates 6 is gradually widened as it becomes farther from the rectifying wall 2, but it is not limited to this.
Moreover, since the baffle plate 6 is divided into the baffle plate halves 6A and 6B, it is possible to attach and detach the baffle plate 6 to and from the inclined sedimentation device 3 not only in the newly installed sedimentation tank 1 but also in the existing sedimentation tank 1. Since the plate halves 6A and 6B can be separated, the baffle plate 6 can be easily attached and detached between the inclined sedimentation device 3 and the water collection trough 7 of the sedimentation tank 1.

Although the sedimentation tank 1 according to the first embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the gist thereof. Other embodiments and modifications of the present invention will be described below, but members and portions that are the same as or similar to those of the above-described embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted.

Next, a sedimentation tank 1 according to a second embodiment of the present invention will be described with reference to FIGS. 5 to 7. FIG.
The sedimentation tank 1 according to the second embodiment differs from the first embodiment in the running structure of the wheels 22, and the rest of the configuration is common.
In the sedimentation tank 1 according to the second embodiment, the shaft portion 16 is horizontally fixed to the support plate 21 hanging down on both the left and right sides of the lower surface of the base material 11, and the shaft portion 16 has wheels 22. Each is rotatably mounted. A groove 22a is formed in the center of the outer peripheral surface of the wheel 22 . As shown in FIG. 6, two wheels 22 supported by the support plate 21 via the shafts 16 are installed in front and behind the baffle plate 6, but may be one or three or more.

On both sides 7b of the water collecting trough 7, a plurality of water collecting holes 7e into which the treated water flowing out from the upper surface 3b of the inclined sedimentation device 3 into the supernatant layer 5 flows are arranged along the longitudinal direction. Both side portions 7b of the water collecting trough 7 are formed at the upper ends thereof with outwardly bent flange portions 7d. A flat reinforcing plate 23 is mounted on the pair of flange portions 7d and connected by welding or the like, and guide rails 24 are fixed to both ends of the reinforcing plate 23 by welding or the like. As shown in FIGS. 5(a) and 5(b), the recessed groove 22a of the wheel 22 is seated on the guide rail 24, and the base member 11 and the baffle plate 6 can travel while being guided by the guide rail 24. . Deformation of the guide rail 24 can be suppressed by installing the reinforcing plate 23 .
Also in the second embodiment, as in the first embodiment, it is possible to narrow or widen the distance between the plurality of baffle plates 6 between the inclined sedimentation device 3 and the water collecting trough 7 for adjustment.

In addition, instead of the configuration shown by the inclined sedimentation device 3 of the sedimentation tank 1 described in the first and second embodiments described above, wheels 15 and 22 are rotatably attached to the upper end of the water collection trough 7 described above, and the base A running surface 7c and a guide rail 24 may be installed on the lower surface of the member 11. FIG. The running surface 7c and the guide rail 24 are included in the guide member.
Although the baffle plate halves 6A and 6B are formed by dividing the baffle plate 6 into two, the shape of the baffle plate halves 6A and 6B is not limited to a substantially L-shaped cross section, and can be any shape. shape can be adopted. Moreover, the baffle plate 6 does not necessarily have to be divided into halves, and may be integrally formed. Even in this case, in the new or existing sedimentation tank 1, the baffle plate 6 is installed prior to the water collection trough 7, or the baffle plate 6 is sequentially installed in the supernatant layer 5 through the area where the water collection trough 7 is not installed. do it.
In addition, in the second embodiment, the reinforcing plate 23 fixed to the pair of flange portions 7d is provided at the upper end portion of the water collecting trough 7, but the reinforcing plate 23 does not necessarily have to be provided. Alternatively, guide rails 24 may be directly formed on the upper portions of both sides 7b of the water collecting trough 7, and the grooves 22a of the wheels 22 may be installed on the guide rails 24. As shown in FIG.

1 Sedimentation basin 3 Inclined sedimentation device 3a Lower surface 3b Upper surface 4 Inclined pipe 5 Skim layer 6 Baffle plate 6A, 6B Half-split baffle portion 7 Water collection trough 7c Running surface 10 Moving device 11 Base material 11a Notch 12 Moving handle 13 Attachment Handle 13b Shafts 15, 22 Wheel 22a Groove 24 Guide rail

Claims (3)

a sedimentation device provided in a sedimentation tank for allowing raw water to pass through to sediment flocs;
a water collection trough provided on the outflow side of the sedimentation device for taking in treated water obtained by treating raw water;
a plurality of baffles disposed between the sedimentation device and the water collection trough and movable and adjustable in mutual spacing;
with
A sedimentation basin , wherein the baffle plate is movable along a guide member disposed above the water collection trough . 2. The sedimentation tank according to claim 1, wherein said baffle is divided into a plurality of pieces. 3. The sedimentation basin according to claim 1, wherein said baffle plate is suspended from a substrate disposed above said water collecting trough.

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