JP2019111533A - Method of repairing sand sedimentation pond - Google Patents

Abstract

To provide a method of repairing a sand sedimentation pond for repairing it into a sand sedimentation pond capable of moving sand more efficiently.SOLUTION: A method of repairing a sand sedimentation pond having an upward opened groove in a pond lower portion 1a, comprises an installation step of installing a space forming member 32 which forms a space S2 closed at a top and is provided with a downward opened suction port 32a, into a groove of an existing trough 83 forming the groove. The method repairs a sand sedimentation pond 1 into a sand sedimentation pond that moves sand sucked in a space S2 toward the downstream side in a discharging direction of fluid, by discharging the fluid into the space S2 so as to make the sand deposited in the groove sucked through the suction port 32a into the space S2.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a method of repairing a settling basin in which sand contained in received water settles in a trough of a trough provided at the bottom of the basin.

  The sewage treatment system receives sewage or sewage such as rainwater, settles the sand contained in the sewage in the bottom of the lower part of the pond or in the ditch provided in the lower part of the pond, and then the bottom or ditch of the lower part of the pond In order to collect sand deposited inside, there is provided a settling basin which is moved in a predetermined direction to remove the collected sand from the sewage. It is known that this sand settling basin is provided with a sand collecting means for moving sand deposited in the bottom and grooves of the lower part of the pond toward the downstream side of the discharge direction of the fluid by the flow of the fluid discharged from the discharge port. It is done. In sand collection using this fluid, the deposited sand may be rolled up by the discharged fluid. For this reason, sloped plates inclined downward toward the discharge direction downstream above the lower part of the pond are disposed at intervals along the discharge direction, and sand is intended to prevent rolling up of sand by the inclined plates. A pond has been proposed (see, for example, Patent Document 1). There is also known a settling basin in which a screw conveyor or the like is arranged at the bottom of the pond.

Japanese Patent Application Laid-Open No. 9-70503

  In the sedimentation basin where such a screw conveyor etc. are arranged, repair may be performed.

  An object of the present invention is to provide a method for renovating a sediment settling basin, which can re- move sand more efficiently.

The method for repairing a sedimentation basin of the present invention to solve the above object is
It is a repair method of a sedimentation basin having a ditch opened upwards at the lower part of the pond,
There is an installation step of installing a space forming member in which a space closed at the upper end portion is formed and a suction port opened downward is provided in the groove of the existing trough forming the groove,
By discharging the fluid into the space, sand accumulated in the groove is sucked into the space from the suction port, and the sand sucked into the space is disposed downstream of the fluid in the discharge direction. It is characterized by remodeling to a settling basin which is moved towards.

In addition, before carrying out the installation step, carry out a removal step of removing the screw conveyor disposed in the groove,
The setting step may be a step including setting a discharge port for discharging a fluid in the space.

In addition, the method for repairing a settling basin of the present invention for solving the above object is
Renovation of a sedimentation basin having a groove having a substantially U-shaped cross section opened upward and provided with a pair of slopes inclined downward toward the groove on both sides in the width direction of the groove Method,
There is an installation step of installing a space forming member in which a space closed at the upper end portion is formed and a suction port opened downward is provided in the groove of the existing trough forming the groove,
By discharging the fluid into the space, sand accumulated in the groove is sucked into the space from the suction port, and the sand sucked into the space is disposed downstream of the fluid in the discharge direction. It is characterized by remodeling to a settling basin which is moved towards.

  Here, the installation step may be a step of arranging the space forming member below the lower ends of the pair of inclined surfaces.

In addition, before carrying out the installation step, carry out a removal step of removing the screw conveyor disposed in the groove,
The setting step may be a step including setting a discharge port for discharging a fluid in the space.

  Furthermore, the installation step may be a step including disposing a water supply pipe connected to the discharge port on one of the pair of inclined surfaces.

  In addition, the installation step may be a step including connecting a water supply pipe connected to the discharge port to an upper end portion of the space forming member.

  ADVANTAGE OF THE INVENTION According to this invention, the renovation method of the sedimentation basin which repairs sand to the sedimentation basin which can be moved more efficiently can be provided.

It is the top view which looked at a sand transfer tank with a good transfer efficiency of sand from upper direction. It is AA sectional drawing of the sedimentation basin shown in FIG. (A) is BB sectional drawing in FIG. 2, (b) is CC sectional drawing in (a). It is a figure for demonstrating notionally the space formation member and groove formation body in the trough shown in FIG. (A) is the fragmentary sectional view which expanded and showed the discharge direction most upstream end vicinity of the trough, (b) is the fragmentary sectional view which looked at (a) from the right. It is a flowchart which shows the flow of the sand removal method. It is sectional drawing which cut | disconnected the sedimentation basin of 2nd Embodiment with a sufficient moving efficiency of sand in the center of the width direction. It is DD sectional drawing of the sedimentation basin shown in FIG. (A) is sectional drawing which shows the modification of the ejection opening shown in FIG. 3, (b) is EE sectional drawing in (a). It is a figure which shows the modification of each of a groove formation body and a space formation member. It is a figure which shows the modification of each of a groove formation body and a space formation member. (A) is a cross-sectional view showing an example of the lower part of the sedimentation basin which is conceived to suppress rolling up of sand while moving the sand sufficiently in the sedimentation basin, and (b) (a) It is a perspective view of a support member shown to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The sedimentation basin is disposed on the upstream side of the sewage treatment system, and after settling sand contained in sewage or sewage such as rainwater, the sedimented sand is moved to a sand collecting pit and removed from the sewage.

  FIG. 1 is a plan view of a sand settling tank with high sand movement efficiency as viewed from above, and FIG. 2 is a cross-sectional view of the sand settling tank shown in FIG.

  As shown in FIG. 1, the sediment settling basin 1 is a pond of rectangular shape in plan view provided with a dust collector 2, a trough 3, a sand collecting pit 4 and a pump well 5. Hereinafter, the long side direction of the sedimentation basin 1 may be referred to as the longitudinal direction, and the short side direction may be referred to as the width direction. The sediment settling basin 1 shown in FIG. 1 receives waste water from the right side of the figure, and the received water flows slowly toward the left side of the figure (see the straight arrows shown in FIGS. 1 and 2). That is, the longitudinal direction of the sedimentation basin is the direction of the flow of water, and in FIGS. 1 and 2, the right side of the figure is the upstream side of the flow of water in the sedimentation basin and the left side is the downstream side. Further, water is discharged to the right side of FIGS. 1 and 2 from a discharge port 7 described later. That is, in FIGS. 1 and 2, the right side of the figure is the downstream side in the discharge direction, and the left side is the upstream side in the discharge direction.

  The dust remover 2 is for removing contaminants (sedue) mixed in the sewage flowing into the sediment settling tank 1 and is installed upstream of the trough 3. The dust remover 2 has an endless chain 21, a plurality of rake 22 attached to the endless chain 21 at intervals, and a filtration screen 23 submerged in water. The endless chain 21 is provided in a state of being erected obliquely on both sides in the width direction of the sand settling basin 1, and as shown in FIG. 2, it is wound around the ground side sprocket 211 and the pond bottom side sprocket 212. There is. When the endless chain 21 is driven, the rake 22 moves in and out of the water. The filtration screen 23 is disposed downstream of the endless chain 21. The filtration screen 23 is formed by arranging vertically extending bars at predetermined intervals (for example, 25 mm to 75 mm), and blocks passage of contaminants having a size equal to or greater than the predetermined intervals. The contaminants blocked by the filtration screen 23 are scraped off by the lake 22, and the scraped contaminants are placed on the ground side on a conveying means such as a belt conveyor (not shown) on the ground side.

  On the downstream side of the dust remover 2, there is provided a sand collecting pit 4 for collecting sand deposited in the lower part 1a of the pond. Inside the collecting pit 4, a sand raising pump 41 is provided. The sand raising pump 41 is disposed in the vicinity of the bottom surface of the sand collecting pit 4 and transports the sand collected in the sand collecting pit 4 to the outside of the sedimentation basin 1. A sand pump 42 is connected to the sand pump 41. The sand sucked by the sand pump 41 is sent to the outside of the sedimentation basin 1 through the sand pipe 42.

  The trough 3 is provided between the sand collecting pit 4 and the pump well 5. That is, the trough 3 is provided downstream of the sand collecting pit 4 and upstream of the pump well 5. The trough 3 has a groove forming body 31 which forms a groove provided in the lower part 1 a of the sedimentation basin 1 as described later. The lower part 1a of the pond is provided with the inclined surface 6 so that it may mention later, and the trough 3 is provided so that the inclined surface 6 may be connected. The sand in the sewage flowing into the settling basin 1 settles toward the lower part 1a of the pond and deposits in the lower part 1a of the pond.

  The pump well 5 is a reservoir where waste water from which sand has been removed is stored. The pump well 5 is disposed on the most downstream side of the sedimentation basin 1. Further, as shown in FIG. 2, the bottom of the pump well 5 is the deepest part in the sediment settling basin 1. A pumping pump 51 is provided inside the pump well 5. The pumping pump 51 moves the sewage stored in the pump well 5 to the outside of the sedimentation basin 1. A pumping pipe 52 is connected to the pumping pump 51. The sewage sucked by the pumping pump 51 is sent through the pumping pipe 52 to a settling basin (not shown) or the like. WL shown in FIG. 2 represents the surface of the sewage. In addition, the height from the bottom of the trough 3 changes, for example in the range of 1 m or more and 5 m or less according to the quantity of the sewage which flows in into the sedimentation basin 1 about the position of this water surface WL.

  The trough 3 is provided at the center in the width direction of the sand settling basin 1 as shown in FIG. 1 and extends in a predetermined direction from a position on the upstream side of the pump well 5. That is, it extends toward the collecting pit 4. The upstream end of the trough 3 is connected to the sand collecting pit 4, and the sand deposited in the trough 3 is moved to the sand collecting pit 4 by the flow of water discharged from a discharge port described later.

  Moreover, the trough 3 of the sedimentation basin 1 shown in FIG. The space forming member 32 is formed over the entire length of the trough 3. A detailed description of the space forming member 32 will be described later.

  FIG. 3A is a cross-sectional view taken along the line B-B in FIG. In FIG. 3A, the lateral direction of the drawing is the width direction of the trough 3.

  The lower part of a pair of inclined surface 6 provided in the pond lower part 1a and the trough 3 provided so that it might be connected with the inclined surface 6 are shown by Fig.3 (a). As shown in FIG. 3A, the inclined surfaces 6 are provided on both sides in the width direction of the trough 3. The inclined surface 6 is made of concrete inclined downward toward the trough 3 and extends in the longitudinal direction between a position upstream of the pump well 5 and the sand collecting pit 4.

  Further, as shown in FIG. 3A, the trough 3 has a first arc-shaped member 3a and a second arc-shaped member 3b each having a cross-sectional shape of 5/8 arcs and a total length of about 15 m. . The first arc-shaped member 3a and the second arc-shaped member 3b are formed by cutting away a portion of a stainless steel pipe member. The first arc-shaped member 3a is a pipe material having a thickness of about 3 to 4 mm and a diameter of about 250 mm, and a portion (3/8 between 9 o'clock and 1 o'clock to 2 o'clock as indicated by the short hand of a watch Arc) is cut away. The second arc-shaped member 3b is a portion of a pipe material having a thickness of about 3 to 4 mm and a diameter of about 150 mm, between the four o'clock and the five o'clock to the nine o'clock 8 arcs) are cut out. The trough 3 is formed by abutting and joining an end corresponding to the 9:00 in the second arc-shaped member 3b at an end corresponding to the 9:00 in the first arc-shaped member 3a. A space forming member 32 and a groove forming body 31 are formed by the first circular arc member 3a and the second circular arc member 3b.

  The space forming member 32 and the groove forming body 31 will be described with reference also to FIG. 4. FIG. 4: is a figure for demonstrating notionally the space formation member and groove formation body in the trough shown in FIG. The figure (a) is a figure which shows a trough, the figure (b) is a figure which shows a space formation member, and the figure (c) is a figure which shows a groove formation body. In FIG. 4, the lateral direction is the width direction of the trough 3, and the direction orthogonal to the paper surface is the extending direction of the trough 3.

  As shown in FIGS. 3A and 4, the trough 3 has a space forming member 32 and a groove forming body 31 extending over the entire length of the trough 3. The width direction of the space forming member 32 and the groove forming body 31 coincides with the width direction of the trough 3, and the extending direction of the space forming member 32 and the groove forming body 31 coincides with the extending direction of the trough 3 There is. Therefore, the width direction of the groove formed by the groove forming body 31 also coincides with the width direction of the trough 3, and the extending direction of the groove also coincides with the extending direction of the trough 3. Each of the space forming member 32 and the groove forming body 31 has a common portion 33 in which a part is common to each other. In FIG. 4, the common portion 33 is shown by being filled. A portion below the portion corresponding to the nine o'clock portion is formed by the first arc-shaped member 3a shown in FIG. 3A, and the portion above the portion corresponding to the nine o'clock portion is the common portion 33. It is formed of the two arc-shaped members 3b. For this reason, in the common portion 33, the portion below the portion corresponding to the nine o'clock becomes the curvature of the first arc-shaped member 3a, and the portion above the portion corresponding to nine o'clock becomes the second arc The curvature of the member 3b is obtained.

  As shown in FIG. 4 (b), the space forming member 32 opens downward. Hereinafter, the portion opened downward is referred to as a suction port 32 a of the space forming member 32. The suction port 32a is an opening having a length L of 80 mm or more in the width direction of the trough 3, and is separated from the bottom 31a of the groove forming body 31 as shown in FIG. 4 (a). The bottom 31 a of the groove forming body 31 corresponds to the bottom of the groove. That is, the suction port 32a is separated from the bottom of the groove. Although the upper end portion 321 of the space forming member 32 is closed, it is arc-shaped and inclined downward. The space forming member 32 forms a space S2 in which a portion above the lower end is closed. In the space S2, the lower end portion connected to the suction port 32a becomes narrower as it approaches the suction port 32a.

  As shown in FIG. 4 (c), the groove forming body 31 is opened upward. Hereinafter, the left half in the width direction of the groove forming body 31 shown in FIG. 4C is referred to as one end side of the groove forming body 31, and the right half in the width direction of the groove forming body 31 is other than the groove forming body 31. It is called the end side. The trough 3 is formed by joining the first arc-shaped member 3a and the second arc-shaped member 3b as shown in FIG. 3 (a). You may form with concrete integrally with 6.

  As shown in FIG. 4A, the space forming member 32 is connected to one end side of the groove forming body 31 by the common portion 33 in a state of being separated from the other end side of the groove forming body 31. Accordingly, the space between the other end side of the groove forming body 31 and the space forming member 32 is opened upward. Hereinafter, the part opening upward is referred to as the opening 34 of the trough 3. Further, of the space in the groove forming body 31, the space excluding the space S2 of the space forming member 32 is referred to as a space S1. That is, a space obtained by combining the space S1 and the space S2 corresponds to the groove, and the opening 34 of the trough 3 corresponds to the opening of the groove. The space forming member 32 in the present embodiment is provided in the groove, and the suction port 32 a is located below the opening of the groove.

  Thus, since the space formation member 32 is connected to one end side in a state of being separated from the other end side of the groove formation body 31, the member for supporting the space formation member 32 can be omitted. As a result, the settling of the sand into the groove is not impeded by the member supporting the space forming member 32 over the entire length of the trough 3, and the string-like contamination is wound around the member supporting the space forming member 32. Problem is solved.

  Further, as described above, the trough 3 of the present embodiment is formed by joining the first arc-shaped member 3a having a diameter of about 250 mm and the second arc-shaped member 3b having a diameter of about 150 mm. Therefore, the gap W between the space forming member 32 and the other end side of the groove forming body 31 is secured about 100 mm over the entire length of the trough 3. Furthermore, since the space forming member 32 and the groove forming body 31 have the common part 33 in which parts are mutually common, it is easy to secure the gap W, and as a result, the size of the trough 3 in the width direction is suppressed. be able to. As described above, the filtration member (here, the filtration screen 23) is installed on the upstream side, and the gap W between the space forming member 32 and the other end side of the groove forming body 31 passes through the filtration member. It is preferable that it is longer than the maximum length of the contaminant (in this case, the screen width of 75 mm in this case) in order to prevent the contaminant that has passed through the upstream filter member from being clogged in the gap W .

  As shown in FIG. 3A, the lower end portion of one of the pair of inclined surfaces 6 (right side in FIG. 3A) is connected to the end of the groove forming body 31 on the other end side. The other one of the inclined surfaces 6 (left side in FIG. 3A) is connected to the upper end portion 321 of the space forming member 32. In the present embodiment, one inclined surface 6 is inclined 45 degrees downward, and the other inclined surface 6 is inclined 42 degrees downward. Sand contained in the sewage flowing into the sediment settling basin 1 settles in the pond lower portion 1 a in the course of the sewage flowing downstream, but tends to deposit in the pond bottom portion 1 a upstream of the settling basin 1. Of the sand that has settled in the lower part 1 a of the pond, the sand that has settled on the slope 6 flows further down the slope 6 toward the trough 3. Sand that has fallen from one of the inclined surfaces 6 enters the groove from the opening 34 of the trough 3. In addition, sand that has fallen from the other inclined surface 6 crosses the arc-shaped side surface 322 of the space forming member 32 and enters the groove from the opening 34 of the trough 3. Since the other inclined surface 6 is connected to the upper end portion 321 of the space forming member 32, sand hardly remains in the connection portion between the upper end portion 321 of the space forming member 32 and the other inclined surface 6. By these, the sand which has settled to the pond lower part 1a is first collected to the bottom part of a ditch.

  Here, as shown in FIG. 1 and FIG. 2, the water supply pipe 71 is connected to the trough 3 at intervals of about 5 m.

  FIG.3 (b) is CC sectional drawing in the same figure (a). In FIG. 3B, the horizontal direction of the drawing is the extending direction of the trough 3, the right side of the drawing is the upstream side (the sand collecting pit 4 side), and the left side is the downstream side (the pump well 5 side).

  As shown in FIGS. 3A and 3B, the water supply pipe 71 is disposed along the other (the left side in FIG. 3A) the inclined surface 6 and the lower end portion is the upper end of the space forming member 32. It penetrates the portion 321 and communicates with the space S2 of the space forming member 32. Further, in the space S2 of the space forming member 32, the discharge port 7 for discharging the fluid in the space S2 is provided in a region where the water supply pipe 71 communicates. The discharge port 7 is formed by dividing the upper portion of the space S <b> 2 in the space forming member 32 by the partition member 72. The partition member 72 includes a horizontal portion 721 extending in a horizontal state in the extending direction of the trough 3 and an inclined portion 722 which is inclined upward from an end of the downstream side (pump well 5 side) of the horizontal portion 721. have. The horizontal portion 721 is connected to both sides in the width direction across the upper end portion on the inner peripheral surface of the space forming member 32, and the end portion on the upstream side (sand collecting pit 4 side) is more than the lower end portion of the water supply pipe 71 It is located upstream. Further, the downstream end of the inclined portion 722 is connected to the downstream side of the inner peripheral surface of the space forming member 32 than the portion connected with the lower end portion of the water supply pipe 71, and the downstream side of the discharge port 7 is It is closed. By these, the area | region which the water supply pipe 71 connects in space S2 of the space formation member 32 is partitioned off by the partition member 72. As shown in FIG. Thus, the partition member 72 has both ends in the width direction of the horizontal portion 721 connected to the space forming member 32, and the downstream end of the inclined portion 722 is connected to the space forming member 32. It is prevented that the string-like contaminant winds around the member 72.

  From the discharge port 7, the water supplied from the water supply pipe 71 is discharged horizontally or substantially horizontally toward the upstream side (see the arrow pointing to the right in FIG. 3B). That is, in FIG. 3B, the right side of the figure is the downstream side in the discharge direction, and the left side of the figure is the upstream side in the discharge direction.

  The discharge port 7 shown in FIG. 3 is provided at the most downstream side in the discharge direction, that is, at a position closest to the sand collecting pit 4.

  Water is discharged from the discharge port 7 into the space S2 of the space forming member 32, so that a pressure difference is generated between the inside (space S2) and the outside (space S1) of the space forming member 32, and deposited at the bottom of the groove. The sand is sucked into the space S2 from the suction port 32a, as indicated by the curved arrow shown in FIG. 3 (a). Furthermore, in the space S2 of the space forming member 32, the sucked sand moves toward the discharge direction downstream side (the sand collecting pit 4 side) by the flow of the water discharged from the discharge port 7. As shown in FIG. 3A, the suction port 32a is an opening squeezed in the width direction (direction orthogonal to the extending direction of the space forming member 32), and the space S2 is expanded from the suction port 32a. It is a space. As described above, since the suction port 32a is an aperture, the sand moving in the space S2 is less likely to come out from the space S2, and the rolling up of the sand can be further suppressed. In addition, the flow of water in the space S2 can be easily maintained, and the sand can be moved further.

  The structure of the discharge port 7 described above is the same for any discharge port 7 connected to the water supply pipe 71. The discharge port 7 is also provided at the most upstream end portion of the trough 3 in the discharge direction. Hereinafter, the discharge port 7 provided at the most upstream end portion in the discharge direction of the trough 3 is referred to as an upstream discharge port, and among the discharge ports 7 connected to the water supply pipe 71 shown in FIG. 1 and FIG. The discharge port 7 on the more distant side may be referred to as an intermediate discharge port, and the discharge port 7 on the side closer to the sand collection pit 4 may be distinguished as a downstream discharge port (discharge port 7 shown in FIG. 3). That is, the discharge port 7 provided on the upstream side of the trough 3 becomes an upstream discharge port, the discharge port 7 provided on the downstream side of the trough 3 becomes a downstream discharge port, and between the upstream discharge port and the downstream discharge port The discharge port provided is an intermediate discharge port. In addition, when viewed from the sedimentation basin shown in FIG. 1, the upstream discharge port is provided on the downstream side of the flow of water in the sediment settling tank, and the downstream discharge port is provided on the upstream side thereof. . Fig.5 (a) is the fragmentary sectional view which expanded and showed the discharge direction highest end vicinity of the trough. In FIG. 5A, the right side of the figure is the downstream side in the discharge direction, and the left side of the figure is the upstream side in the discharge direction.

  As shown to Fig.5 (a), the plate-shaped upstream end surface wall 36 is attached to the end surface used as the discharge flow direction most upstream end of the trough 3. As shown in FIG.

  FIG. 5B is a partial cross-sectional view of FIG. 5A as viewed from the right. That is, FIG. 5 (b) is a view of the upstream end surface wall 36 viewed from the downstream side in the discharge direction, and the back side of the paper surface is the upstream side in the discharge direction.

  The upstream discharge port 7 provided in the discharge direction most upstream end part of the trough 3 is shown by Fig.5 (a) and the same figure (b). In the upstream discharge port 7, the inclined portion 722 of the partition member 72 of the downstream discharge port 7 (the discharge port 7 shown in FIG. 3) is omitted, and the discharge direction upstream end of the horizontal portion 721 is connected to the upstream end surface wall 36 It is formed. On the upstream end side of the upstream end face wall 36 in the discharge direction of the upstream discharge port 7, a flat long hole shaped discharge opening 36a is formed. An L-shaped tube 73 is connected to the discharge direction upstream side of the discharge opening 36a. The L-shaped tube 73 is a tube having an L-shape in plan view, and is connected to a supply tube (not shown) for supplying water. The water supplied from the supply agent is discharged downstream from the discharge opening 36a through the L-shaped pipe 73 and further discharged horizontally or substantially horizontally from the upstream discharge port 7 (FIG. 5 (a)). See the arrow in). The upstream discharge port 7 is configured to connect the water supply pipe 71 to the upper end portion 321 of the space forming member 32, instead of the L-shaped pipe 73, similarly to the downstream discharge port 7 (discharge port 7 shown in FIG. 3). May be

  It is preferable that the discharge flow velocity of water is 8 m / sec or more for all three discharge ports 7. If it is less than 8 m / sec, the flow velocity will be insufficient, and the sand may not be moved by a predetermined distance in relation to the water pressure. If the sand can not be moved by a predetermined distance, a large number of discharge ports are required in the sand movement direction, and the number of pipes to the discharge ports is also large, which makes the apparatus miscellaneous and uneconomical. Further, the discharge pressure of water at each discharge port 7 is 0.05 MPa or more and 0.3 MPa or less.

  According to the sedimentation basin 1 of the present embodiment described above, it is possible to suppress the rolling up of the sand while moving the sand sufficiently. In addition, it is possible to sufficiently suppress the winding of string-like contaminants contained in the sewage.

  Then, the sand removal method which removes the sand deposited on the pond lower part 1a of the sedimentation basin 1 of this embodiment from the sedimentation basin 1 is demonstrated.

  FIG. 6 is a flowchart showing the flow of the sand removal method.

  When the waste water flowing into the sedimentation basin 1 passes through the dust collector 2 shown in FIG. 2, the contaminants (sedue) mixed in the waste water are removed. The waste water that has passed through the dust collector 2 passes the sand collection pit 4 to reach the upstream end of the trough 3 and further flows in the extension direction of the trough 3. While the waste water flows through the upstream portion of the trough 3, most of the sand contained in the waste water settles in the lower part 1 a of the settling basin 1. Some sand settles in the sand collecting pit 4 and some sand settles on the inclined surface 6, and the sand settled on the inclined surface 6 flows further down the inclined surface 6 toward the trough 3. In addition, the sand that has settled to the upper end portion 321 of the space forming member 32 flows toward the bottom of the groove forming body 31 along the arc-shaped side surface 322 of the space forming member 32. Thus, sand is deposited in the grooves.

  In the sand removing method according to the present embodiment, first, the sand raising pump 41 shown in FIG. 1 and FIG. 2 is driven to remove the sand in the sand collecting pit 4 from the sand collecting pit 4 before performing the sand collecting process described later. (Step S1). At this stage, the sand deposited in the sand collecting pit 4 is mainly the sand deposited in the sand collecting pit 4 by settling in the sand collecting pit 4 among the sand in the sewage flowing into the sediment settling tank 1.

  Next, in a state where the sand raising pump 41 is driven, 1500 liters per minute of water is discharged for 3 minutes under water from only the downstream discharge port 7 shown in FIG. 3 among the three discharge ports 7 (step S2) . In this step S2, water is discharged into the space S2 partitioned by the space forming member 32. By discharging water from the downstream discharge port 7 into the space S2, a pressure difference is generated between the inside (space S2) and the outside (space S1) of the space forming member 32, and sand deposited in the upstream portion in the groove Is drawn into the space S2 from the suction port 32a (see the arrow of the curve shown in FIG. 3A). Further, in the space S2 of the space forming member 32, the sucked sand moves toward the sand collecting pit 4 by the flow of water discharged from the downstream discharge port 7. The sand moving in the space S2 of the space forming member 32 does not easily come out of the space forming member 32 in the portion where the pressure difference is generated, and the rolling up of the sand is suppressed. Thus, the sand deposited on the downstream portion in the discharge direction in the groove moves in the space S2 of the space forming member 32, and eventually reaches the sand collection pit 4. The sand that has reached the sand collecting pit 4 is transported to the outside of the sedimentation basin 1 by the sand pumping pump 41 which has started driving in the previous step S1, and the sand from the sedimentation basin 1 is removed. The removal of sand here corresponds to an example of the discharging process.

  Then, the discharge of water from the downstream discharge port 7 is stopped, and this time, 1500 liters of water per minute is discharged from the three discharge ports 7 only for three minutes under water (step S3). . The driving of the sand raising pump 41 is continued also during the execution of step S3. By discharging water into the space S2 of the space forming member 32 in step S3 as in step S2, a pressure difference is generated between the inside (space S2) and the outside (space S1) of the space forming member 32, and this time The sand deposited around the intermediate discharge port 7 in the groove is again sucked into the space S2 from the suction port 32a. Further, the sucked sand moves in the space S2 of the space forming member 32 toward the downstream discharge port 7 shown in FIG. 3 by the flow of water discharged from the intermediate discharge port 7 and reaches the periphery of the downstream discharge port 7 To reach. At the periphery of the downstream discharge port 7, the momentum of the water from the intermediate discharge port 7 decreases, so that the sand that has reached the periphery of the downstream discharge port 7 descends from the suction port 32a toward the bottom of the groove forming body 31, It returns to space S1 of trough 3 once. That is, sand deposits around the downstream discharge port 7 in the space S1 of the trough 3.

  Next, the discharge of water from the intermediate discharge port 7 is stopped, and again, 1500 liters of water per minute is discharged under water for 3 minutes from only the downstream discharge port 7 shown in FIG. Step S4). The sand deposited around the downstream discharge port 7 in the space S1 of the trough 3 is also sucked into the space S2 from the suction port 32a by this step S4, and the sucked sand flows toward the sand collecting pit 4 in the space S2. Move and reach sand collecting pit 4 soon. The driving of the sand raising pump 41 continues also during the execution of step S4, and the sand that has reached the sand collecting pit 4 is removed from the sedimentation basin 1 by the sand raising pump 41. That is, removal of sand by the sand raising pump 41, which corresponds to an example of the discharging process, is also performed.

  This time, the discharge of water from the downstream discharge port 7 is stopped, and 1500 liters per minute of water is discharged from the upstream discharge port 7 of the three discharge ports 7 only for 3 minutes in water (step S5). The driving of the sand raising pump 41 is continued also during the execution of step S5. Also in step S5, water is discharged into the space S2 of the space forming member 32 in the same manner as in steps S2 to S4, so that a pressure difference occurs between the inside (space S2) and the outside (space S1) of the space forming member 32. Sand deposited around the upstream discharge port 7 in the space S1 of the trough 3 is sucked into the space S2 from the suction port 32a. Furthermore, the sucked sand moves in the space S 2 of the space forming member 32 toward the intermediate discharge port 7 by the flow of water discharged from the upstream discharge port 7 and reaches the periphery of the intermediate discharge port 7. As the momentum of water from the upstream discharge port 7 decreases around the intermediate discharge port 7, sand that has reached the periphery of the intermediate discharge port 7 descends from the suction port 32a toward the bottom of the groove forming body 31, Sand is deposited around the intermediate discharge port 7 in the space S1 of the trough 3.

  Subsequently, the discharge of water from the upstream discharge port 7 is stopped, and again, 1500 liters per minute of water is discharged under water for 3 minutes from only the intermediate discharge port 7 as in step S3 (step S6). The driving of the sand raising pump 41 is continued also during the execution of step S6. Also in step S6, sand deposited around the intermediate discharge port 7 in the space S1 of the trough 3 is sucked into the space S2 from the suction port 32a, and the sucked sand flows toward the downstream discharge port 7 in the space S2. After moving, sand is deposited around the downstream discharge port 7 in the space S1 of the trough 3 eventually.

  Next, the discharge of water from the intermediate discharge port 7 is stopped, and three times, 1500 liters of water per minute is discharged under water for 3 minutes from step S2 only from the downstream discharge port 7 shown in FIG. (Step S7). Also in this step S7, sand deposited around the downstream discharge port 7 in the space S1 of the trough 3 is sucked into the space S2 from the suction port 32a, and the sucked sand is directed to the sand collecting pit 4 in the space S2. Move and reach sand collecting pit 4 soon. The driving of the sand raising pump 41 continues also during the execution of step S7, and the sand that has reached the sand collecting pit 4 is removed from the sedimentation basin 1 by the sand raising pump 41. That is, removal of sand by the sand raising pump 41, which corresponds to an example of the discharging process, is also performed. In addition, the sand rising pump 41 continues to be driven for a predetermined time even after the discharge of water from the downstream discharge port 7 is finished, and the removal of sand corresponding to an example of the discharging process is continuously performed.

  Thus, the sand contained in the received water passes through the space S2 of the space forming member 32 for six stages and collects in the sand collecting pit 4. Steps S2 to S7 described above correspond to a sand collecting process. It is not necessary to drain the water in the sedimentation basin 1 and reduce or eliminate all the water in the sedimentation basin 1 before carrying out the process in a state where the sewage is continuously received in the sedimentation basin. The fluid discharged from the discharge port 7 in the sand collecting process may use the waste water received in the waste water treatment site, but may be any other fluid.

  Then, when the predetermined time has elapsed, the sand raising pump 41 which has started driving in step S1 is stopped (step S8), and when the predetermined time has elapsed, or sand has accumulated to a certain extent in sand collecting pit 4 by sedimented sand. Step S1 is performed again. In this manner, steps S1 to S8 are repeatedly performed after receiving the waste water is started.

  In the above description, the driving of the sand raising pump 41 is continued from the start in step S1 to the stop in step S8, but is stopped when the sand in the sand collecting pit 4 is reduced to a certain amount. Alternatively, the driving of the sand raising pump 41 may be stopped during the execution of steps S3 and S5 to S6.

  According to the sand removing method of the present embodiment, it is possible to move the sand sufficiently while suppressing the rolling up of the sand in the settling basin 1, and remove the sand from the settling basin. Moreover, in the sand removal method of this embodiment, sand flows into the pump well 5 arrange | positioned most downstream of the sedimentation basin 1 by making the transfer direction of sand into the direction which goes to the upstream from the downstream side. To prevent. That is, in the present embodiment, a sand collecting location (the sand collecting pit 4 in the present embodiment) is provided on the downstream side in the discharge direction, that is, on the downstream side in the sand transfer direction (corresponding to the upstream side of the sedimentation basin 1 in the present embodiment) Sewage discharge locations (pump wells 5 in the present embodiment) are provided on the discharge direction upstream side, that is, on the sand transfer direction upstream side (corresponding to the downstream side of the settling basin 1 in the present embodiment).

  Next, the sedimentation basin 1 of the second embodiment will be described. In the following description, components having the same names as the components described so far will be described with the reference numerals used so far, and duplicate descriptions may be omitted.

  FIG. 7: is sectional drawing which cut | disconnected the sedimentation basin of 2nd Embodiment with the moving efficiency of sand by the width direction center. Also in FIG. 7, the right side of the figure is the upstream side, and the left side is the downstream side.

  The sediment settling basin 1 shown in FIG. 7 is different from the sediment settling basin 1 shown in FIG. 1 in the position where the sand collecting pit 4 is provided. In the sediment settling basin 1 shown in FIG. 7, the upstream trough 3 ′ is provided on the upstream side of the sand collection pit 4, and the downstream trough 3 ′ ′ is provided on the downstream side of the sand collection pit 4. The overall length of the upstream trough 3 ′ is about 5 m, and the overall length of the downstream trough 3 ′ ′ is about 10 m, twice the upstream trough 3 ′. In the upstream trough 3 ', one outlet 7 to which the water supply pipe 71 is connected is provided at the upstream end portion, and in the downstream trough 3' '', the outlet 7 to which the water supply pipe 71 is connected extends It is provided at each of the middle and downstream end portions of the direction. Note that the discharge port 7 of the upstream trough 3 'and the discharge port 7 provided at the downstream end portion of the downstream trough 3' "are the discharge ports 7 shown in FIG. 5 in the sedimentation basin 1 of the first embodiment. A similar configuration may be made. Moreover, although the same dust remover 2 as the dust remover 2 shown in FIG. 2 is installed further upstream than the upstream trough 3 ', it is not shown in FIG.

  FIG. 8: is DD sectional drawing of the sedimentation basin shown in FIG. In FIG. 8, the left and right direction of the drawing is the width direction of the trough.

  The sediment settling basin 1 of the second embodiment is a pond having a trough in which a screw conveyor or the like has been arranged, and the lower part 1a of the pond has been repaired. The trough before the renovation is formed by arranging two troughs on the upstream side and the downstream side of the sand collecting pit 4 in the width direction, and the dimension in the width direction of each trough is about 400 mm. Moreover, the inclined surface is connected to the both sides of the width direction at each of these troughs. In FIG. 8, the portion 8 of the lower pond portion 1 a before being repaired is indicated by cross hatching. Hereinafter, the trough before the renovation is referred to as an existing trough 83, and the inclined surface before the renovation is referred to as an existing inclined surface 86.

  In the sediment settling basin 1 of the second embodiment, the upstream trough 3 'and the downstream trough 3' '' are disposed in the existing trough 83 from which the screw conveyor is removed, etc. It is a pond that

  As shown in FIG. 8, in the sand settling basin 1 of the second embodiment, the downstream trough 3 ′ ′ is disposed in each of the two existing troughs 83, and between the existing trough 83 and the downstream trough 3 ′ ′ Concrete C is being cast. The two downstream troughs 3 ′ ′ are disposed symmetrically in the width direction such that the space forming members 32 are positioned on the outer side in the width direction, and the upper end portion of each space forming member 32 has a width A water supply pipe 71 indicated by an alternate long and short dash line is connected from the outside of the direction. Moreover, the part connected in the downstream side trough 3 '' 'in the existing inclined surface 86 in the inclined surface 6 is formed of the cast concrete C. As shown in FIG. A portion of the inclined surface 6 connected to the downstream trough 3 ′ ′ from the existing inclined surface 86 may be formed of a plate material such as metal. The structures of the downstream trough 3 ′ ′ and the inclined surface 6 connected to the downstream trough 3 ′ ′ described above are the same as in the upstream trough 3 ′ and the inclined surface 6 connected to the upstream trough 3 ′. .

  In the sediment settling basin 1 of the second embodiment, an existing lower part of a pond having a trough on which a screw conveyor or the like is disposed can be used. In addition, the sedimentation basin 1 of 1st Embodiment shown in FIG. 1 may also be the existing pond lower part which has a trough in which a screw conveyor etc. was arrange | positioned, and was repaired.

  Then, about the modification of the settling basin 1 demonstrated until now, it demonstrates centering on a different point from the structure demonstrated until now. Further, in the drawings of the modified example described below, the space forming member 32 and the groove forming body 31 are conceptually shown in a circled part.

  Fig.9 (a) is sectional drawing which shows the modification of the ejection opening shown in FIG. 3, and the same figure (b) is EE sectional drawing in the same figure (a). In FIG. 3A, the lateral direction of the drawing is the width direction of the trough 3, and in FIG. 3B, the lateral direction of the drawing is the extending direction of the trough 3.

  The pond lower portion 1a shown in FIG. 9 is different from the pond lower portion 1a shown in FIG. 3 in that the discharge port 7 can be removed from the space forming member 32. As shown in FIG. 9, a removable lid 323 is provided on the upper part of the space forming member 32, and a water supply pipe 71 is connected to the lid 323 from the upper side, and the lid 323 is partitioned on the lower surface A member 72 is attached. A removable L-shaped joint 711 is provided at a tip portion of the water supply pipe 71 connected to the lid 323. The partition member 72 has a U-shaped portion 723 having a U-shaped cross-sectional shape, and an inclined portion 722 connected to the downstream end of the U-shaped portion 723. Both ends in the width direction of the U-shaped portion 723 The portion and the downstream end of the inclined portion 722 are fixed to the lower surface of the lid 323 by welding or the like. The discharge port 7 is formed by the U-shaped portion 723 and the lid 323.

  In the pond lower portion 1a shown in FIG. 9, after the L-shaped joint 711 is removed from the water supply pipe 71, the discharge port 7 can be removed together with the lid 323 from the space forming member 32, and maintenance etc. of the discharge port 7 can be performed. . An opening may be provided in the vicinity of the portion where the partition member 72 is attached in the space forming member 32 so that the maintenance of the discharge port 7 can be performed by extending the hand from this opening. The opening is closed by a removable lid, an openable lid connected by a hinge or the like, and the like.

  FIGS. 10 and 11 are views showing modifications of the groove forming body and the space forming member. In FIGS. 10 and 11, the horizontal direction of the drawing is the width direction of the trough 3. In addition, in FIG. 10 and FIG. 11, in order to simplify drawing, the water supply pipe is abbreviate | omitted.

  The trough 3 shown in FIG. 10 (a) is, as conceptually shown in the circle of the figure, a concrete grooved body 31 having a U-shaped cross-sectional shape, and a second shown in FIG. 3 (a). A space forming member 32 having the same shape as the arc-shaped member 3 b is provided. The space forming member 32 is connected to the upper end portion (see the dotted line in FIG. 10A) on one end side of the groove forming body 31. Thus, the space S2 of the space forming member 32 has a region located above the groove formed by the groove forming body 31. That is, a part of the space forming member 32 of this modification is provided outside the groove.

  The trough 3 shown in FIG. 10 (b) has a groove forming body 31 having a U-shaped cross-sectional shape and a part of one end side of the groove forming body 31 as conceptually shown in the circle of the figure. And a space forming member 32 which is shared. The common part of the groove forming body 31 and the space forming member 32 corresponds to an intermediate part in the vertical direction in the one end side part of the groove forming body 31. That is, the space forming member 32 of the present modification is provided in the groove, and is connected to an intermediate part in the vertical direction on one end side of the groove forming body 31. Thus, the space S2 of the space forming member 32 is located between the vertical direction of the groove formed by the groove forming body 31. In addition, since the part which protruded in the groove | channel of the space formation member 32 is curving in circular arc shape toward the downward direction, it is less likely that sand will accumulate on the space formation member 32. FIG.

  The trough 3 shown in FIG. 11 (a) is, as conceptually shown in the circle of the figure, a groove forming body 31 having a U-shaped cross section whose upper side is open, and a U-like shape whose lower side is open. And a space forming member 32 having a cross-sectional shape. As described above, the groove forming body 31 and the space forming member 32 may have a U-shaped cross section or may have a V-shaped or the like. Furthermore, it may be a combination of the groove forming body 31 or the space forming member 32 having an arc-shaped or U-shaped cross-sectional shape and the groove forming body 31 or the space forming member 32 having a U-shaped cross-sectional shape. .

  The groove forming body 31 of the trough 3 shown in FIG. 11B has a U-shaped portion 311 having a U-shaped cross-sectional shape, and one end side end portion of the U-shaped portion 311 in the width direction of the trough 3 An inwardly extending horizontal portion 312 and a mounting portion 313 directed downward from the tip end portion of the horizontal portion 312 are provided. The space forming member 32 has a cross-sectional shape of a 3/4 arc opening downward. The upper end portion of the space forming member 32 is attached to the mounting portion 313 of the groove forming body 31. The space formation member 32 of this modification does not have a common part shared with a part of the groove formation body 31.

  Also in the modification shown in FIGS. 10 and 11, the member supporting the space forming member 32 can be omitted, and the sedimentation of sand from the opening 34 of the trough 3 into the groove is ensured over the entire length of the trough 3 . In addition, the problem that the string-like inclusions wrap around the member supporting the space forming member 32 can be solved.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims. For example, although the space forming member 32 is provided over the entire length of the trough 3 in the above embodiment, the space forming member 32 is provided in such a range that there is no risk of the cord-like inclusion contained in the received sewage being wounded. May be slightly shorter than the total length of the trough 3. In particular, when the overall length of the trough 3 is long, etc., the space forming member 32 may be divided in the extending direction of the trough 3 within a range where there is no risk of the cord-like inclusions being wound. Further, the arrangement position of the discharge port 7 is not limited to the upper side in the space S2 of the space forming member 32, and may be provided at any position in the space S2, such as the lower side or the center in the space S2. Furthermore, the discharge port 7 does not necessarily need to be installed in the space S2 of the space forming member 32, and is installed obliquely downward below the space forming member 32 (suction port 32a). The fluid may be able to be discharged into the space S2.

  In addition, even if it is the structure requirements contained only in each description of each modification explained above, the configuration requirements may be applied to other modifications.

  Finally, technical ideas that are not directly related to the present invention will be disclosed.

  FIG. 12 (a) is a cross-sectional view showing an example of the lower part of the sand settling basin in which the sand rolling-up is suppressed while sufficiently moving the sand in the sand settling basin.

  The pond lower portion 9 shown in FIG. 12A includes a trough 91 forming a groove, inclined surfaces 92 provided on both sides in the width direction of the trough 91, and a space forming member 93 extending along the trough 91. A support member 94 for supporting the space forming member 93 and a discharge port 95 are provided. In FIG. 12A, the direction perpendicular to the paper surface is the extending direction of the trough 91, and the lateral direction of the drawing is the width direction of the trough 91. For example, the trough 91 is formed to have a total length of about 10 to 20 m and a width of about 300 to 350 mm. The space forming member 93 extends over the entire length of the trough 3 and forms a space S9 in which the upper end portion is closed. Further, the space forming member 93 is provided with a suction port 93 a which is opened downward and is separated from the bottom of the trough 91. The discharge port 95 is disposed in the space S9, and water supplied from a water supply pipe (not shown) is discharged along the space forming member 93. In FIG. 12A, the near side in the drawing is the discharge direction downstream side become.

  The support member 94 will be described with reference also to FIG. The figure (b) is a perspective view of the support member shown to the figure (a).

  As shown in FIG. 12B, the support member 94 has a plate-like horizontal portion 941 and a plate-like vertical portion 942 fixed to the horizontal portion 941 by welding or the like. As shown to the figure (a), the supporting member 94 is installed so that the horizontal part 941 may block up the trough 91 upper part. The length of the horizontal portion 941 in the extension direction of the trough 91 is, for example, about 100 to 200 mm, and the support member 94 is several meters along the trough 91 so as not to inhibit the sedimentation of sand into the trough 91. It will be installed more than once. The upper end portion of the space forming member 93 is fixed to the lower surface of the horizontal portion 941. Further, an arc-shaped notch 942 a is formed in the vertical portion 942, and the space forming member 93 is fixed in a state of being fitted into the notch 942 a. The vertical portion 942 is for preventing wrapping of a string-like contaminant (for example, hair or vinyl string) contained in the received waste water.

  The lower part 9 of the pond shown in FIG. 12A is in a state of being submerged in water by the received sewage, and sand contained in the sewage settles in the trough 91. When water is discharged under water from the discharge port 95, a pressure difference occurs between the inside (space S9) of the space forming member 93 and the outside, and sand deposited in the trough 91 is sucked from the suction port 93a (FIG. 12 (a See the arrow of the curve shown in). Further, in the space S9 of the space forming member 93, the sucked sand is moved to the downstream side in the discharge direction by the flow of the water discharged from the discharge port 95. As a result, it is possible to suppress the rolling up of the sand while moving the sand sufficiently.

The settling basin described so far is a settling basin where sand contained in the received water settles in a ditch provided at the bottom of the basin,
A space forming member forming a closed space at an upper end portion, and provided with a suction port below the upper end portion and spaced from the bottom of the groove;
And an outlet for discharging a fluid into the space,
The suction port functions as an opening that sucks sand accumulated in the groove into the space by discharging fluid from the discharge port.
The space forming member functions as a path through which sand sucked into the space moves toward the downstream side in the discharge direction of the fluid by discharging the fluid from the discharge port,
The lower part of the pond has a groove forming body for forming the groove,
The space forming member is connected to one end side of the groove forming body in the width direction orthogonal to the extending direction of the groove, the space forming member being apart from the other end side, and connected to the one end side, It is characterized in that it is provided along the extending direction of the groove.

  Here, the space forming member may be provided at an interval in the extending direction of the groove while having a sufficient length. The sufficient length referred to here may be longer than the length of the generally conceivable string-like contaminant.

  Further, each of the groove forming body and the space forming member may have a cross-sectional shape of C-shape (arc shape), U-shape, V-shape, U-shape or the like.

  The space forming member may be connected to the upper end portion on the one end side of the groove forming body, or may be connected to a halfway portion in the vertical direction on the one end side.

  According to the sedimentation basin, the fluid is discharged from the discharge port into the space, so that a pressure difference is generated between the inside (the space) of the space forming member and the outside, and the sand deposited in the lower part of the pond is The air is sucked into the space from the suction port. Furthermore, in the space, the sucked sand moves toward the discharge direction downstream side by the flow of the fluid. The sand moving in the space is unlikely to come out of the space forming member at the portion where the pressure difference is generated, and the rolling up of the sand is suppressed. In addition, since the space forming member is connected to the one end side of the groove forming body apart from the other end side and provided along the extending direction of the groove, the groove formation is performed. Sand settling can be received between the other end of the body and the space forming member. Therefore, the space forming member can be formed long in the extending direction of the groove, and the winding of long contaminants can be suppressed.

In the above-mentioned sedimentation basin, the above-mentioned space formation member is provided in the above-mentioned slot, and
The suction port may be located below the opening of the groove.

  According to this aspect, the sand settled in the groove can be easily sucked into the space from the suction port, and the sand can be moved more efficiently.

  Moreover, in the said sedimentation basin, the said space formation member may make one part and a part of said groove formation body common.

  By sharing a part in this way, it is easy to secure a space between the other end side of the groove forming body and the space forming member which allows sand to settle in the groove, and the sand is in the groove Makes it easier to settle.

  Here, the cross-sectional shape of each of the space forming member and the groove forming body may be an arc shape having different curvatures. In this case, the common part of the space forming member and the groove forming body may have a curvature of the space forming member or may have a curvature of the groove forming body, It may be a combination of the portion of curvature of the member and the portion of curvature of the groove forming body.

  Furthermore, in the said sedimentation basin, the said space formation member may be comprised by the said upper-end part by the curved surface.

  By this, it is suppressed that sand accumulates on the above-mentioned space formation member.

Moreover, in the said sedimentation basin, the said pond lower part has a pair of inclined surface sloping downward toward this groove | channel on the both sides of the width direction of the said groove,
The lower end portion of one of the pair of inclined surfaces is connected to the other end side of the groove forming body,
The lower end portion of the other of the pair of inclined surfaces may be connected to the upper end portion of the space forming member.

  One of the pair of inclined surfaces has its lower end connected to the other end side of the groove forming body, so sand flows from the one inclined surface into the groove. Further, since the lower end portion of the other of the pair of inclined surfaces is connected to the upper end portion of the space forming member, the space forming member is formed of a curved surface from the other inclined surface. Sand that has fallen to the upper end portion smoothly flows into the groove without accumulating at the upper end portion of the space forming member.

  Furthermore, in the said sedimentation basin, the said space formation member may be connected to the said one end side over the substantially full length of the said groove | channel.

  By so doing, sand can be sucked into the space over substantially the entire length of the groove, and the possibility that the mixture wraps around the space forming member itself is further reduced.

Also, in the above description,
It is a settling basin where sand contained in the received water settles in a ditch provided in the lower part of the pond,
A groove forming body having a first arc-shaped portion opened upward, which forms the groove;
A space forming member which forms a closed space and is provided with a suction port connected to the space;
The suction port functions as an opening for sucking sand accumulated in the groove into the space by discharging the fluid into the space,
The space forming member functions as a path along which sand sucked into the space moves toward the downstream side of the discharge direction of the fluid by discharging the fluid into the space, and the groove And a second arc-shaped portion which is open downward and which is smaller in the radial direction than the first arc-shaped portion.
The second arc-shaped portion is supported by the first arc-shaped portion by connecting one end of each of the first arc-shaped portion and the second arc-shaped portion in the width direction orthogonal to the extending direction. 1. A sediment settling basin characterized in that the inner circumferential surface is a continuous curved surface from the circular arc portion to the second circular arc portion.
Explained.

Furthermore, in the above description,
It is a settling basin where sand contained in the received water settles in the trough of the trough provided at the bottom of the pond,
The trough forms an upwardly open groove forming member that forms the groove, and a space forming member that forms a closed space, is provided with a suction port connected to the space, and extends along the groove. Were constructed,
The suction port is a downward opening, and functions as an opening for sucking sand accumulated in the groove into the space by discharging the fluid into the space,
The space forming member functions as a path through which sand sucked into the space moves toward the downstream side of the discharge direction of the fluid by discharging the fluid into the space,
One end portion of the groove forming body in the width direction orthogonal to the extending direction of the groove and one end portion in the width direction of the space forming member are connected to each other.
I also explained about

  Furthermore, in this sedimentation basin, the groove forming body may be constituted by a plurality of planes extending in the extending direction.

  In the above-mentioned sedimentation basin, the above-mentioned space may become so narrow that the part by the side of the above-mentioned suction opening approaches this suction opening.

Also, in the above description,
It is a settling basin where sand contained in the received water settles in a ditch extended to the sand collection pit provided in the lower part of the pond,
An upwardly open groove forming body forming the groove;
And a space forming member which forms a closed space, is provided with a suction port connected to the space, and extends along the groove.
The suction port is a downward opening, and functions as an opening for sucking sand accumulated in the groove into the space by discharging the fluid into the space,
The space forming member functions as a path along which sand sucked into the space moves toward the sand collecting pit by discharging the fluid into the space.
One end portion of the groove forming body in the width direction orthogonal to the extending direction of the groove and one end portion in the width direction of the space forming member are connected to each other.
I also explained about

  Further, the groove forming body may have a plurality of flat portions extending in the extending direction.

DESCRIPTION OF SYMBOLS 1 sedimentation basin 1a lower part of a pond 3 trough 31 groove formation body 32 space formation member 321 upper end part 33 common part 34 opening 4 sand pit 6 inclined surface 7 discharge port S1, S2 space

Claims (7)

It is a repair method of a sedimentation basin having a ditch opened upwards at the lower part of the pond,
There is an installation step of installing a space forming member in which a space closed at the upper end portion is formed and a suction port opened downward is provided in the groove of the existing trough forming the groove,
By discharging the fluid into the space, sand accumulated in the groove is sucked into the space from the suction port, and the sand sucked into the space is disposed downstream of the fluid in the discharge direction. Renovation method of settling basin characterized by renovating to settling basin which is moved toward. Before carrying out the installation step, carry out a removal step of removing the screw conveyor disposed in the groove,
The method according to claim 1, wherein the setting step includes a step of setting an outlet for discharging a fluid in the space. Renovation of a sedimentation basin having a groove having a substantially U-shaped cross section opened upward and provided with a pair of slopes inclined downward toward the groove on both sides in the width direction of the groove Method,
There is an installation step of installing a space forming member in which a space closed at the upper end portion is formed and a suction port opened downward is provided in the groove of the existing trough forming the groove,
By discharging the fluid into the space, sand accumulated in the groove is sucked into the space from the suction port, and the sand sucked into the space is disposed downstream of the fluid in the discharge direction. Renovation method of settling basin characterized by renovating to settling basin which is moved toward.   The said installation process is a process of arrange | positioning the said space formation member below rather than the lower end of the said pair of inclined surfaces, The renovation method of the sedimentation basin of Claim 3 characterized by the above-mentioned. Before carrying out the installation step, carry out a removal step of removing the screw conveyor disposed in the groove,
The said installation process is a process which also includes installing the discharge port which discharges a fluid in the said space, The renovation method of the sedimentation basin of Claim 3 or 4 characterized by the above-mentioned.   The said installation process is a process also including arrange | positioning the water supply pipe connected to the said discharge outlet in one inclined surface of the said pair of inclined surfaces, The improvement of the sedimentation basin of Claim 5 characterized by the above-mentioned. Method.   The method according to claim 5, wherein the installing step includes a step of connecting a water supply pipe connected to the discharge port to an upper end portion of the space forming member.

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