JP6923962B2 - Settling basin - Google Patents

Description

The present invention relates to a sand basin in which sand contained in the received water settles in a trough groove provided in the lower part of the pond.

The sewage treatment system receives sewage such as sewage or rainwater, and after the sand contained in the sewage is settled in the bottom of the pond or in the groove provided in the bottom of the pond, the bottom or groove of the bottom of the pond. Some have a sand basin that moves the sand in a predetermined direction to collect the sand that has accumulated inside and removes the collected sand from the sewage. It is known that this sand basin is equipped with a sand collecting means for moving the sand accumulated in the bottom surface or the groove at the bottom of the pond toward the downstream side in the discharge direction of the fluid by the flow of the fluid discharged from the discharge port. Has been done. In sand collection using this fluid, the accumulated sand may be rolled up by the discharged fluid. For this reason, inclined plates inclined downward toward the downstream side in the discharge direction are arranged above the lower part of the pond at intervals along the discharge direction, and the inclined plates are used to prevent sand from rolling up. A pond has been proposed (see, for example, Patent Document 1 and the like).

Japanese Unexamined Patent Publication No. 9-70503

In the sand basin described in Patent Document 1, it is not possible to prevent the sand from rolling up while sufficiently moving the sand.

An object of the present invention is to provide a sand basin capable of suppressing the rolling up of sand while sufficiently moving the sand.

The sand basin of the present invention that solves the above object is
A sand basin in which the sand contained in the received water settles in a ditch extending toward the sand collection pit provided at the bottom of the pond.
A groove-forming body that opens upward to form the groove,
A space-forming member that forms a closed space, is provided with a suction port connected to the space, and extends along the groove.
A discharge port arranged in the space and discharging a fluid into the space,
A support member for supporting the space forming member is provided .
The support member is characterized in that it supports the outer peripheral surface of the space forming member.

Further, the support member may be interposed between the space forming member and the groove forming body.

According to the present invention, it is possible to provide a sand basin capable of suppressing the rolling up of sand while sufficiently moving the sand.

It is a top view of a sand basin with good sand movement efficiency. FIG. 3 is a cross-sectional view taken along the line AA of the sand basin shown in FIG. (A) is a cross-sectional view taken along the line BB in FIG. 2, and FIG. 2B is a cross-sectional view taken along the line CC in FIG. It is a figure for conceptually explaining a space forming member and a groove forming body in the trough shown in FIG. (A) is a partial cross-sectional view showing the vicinity of the most upstream end of the trough in the discharge direction in an enlarged manner, and (b) is a partial cross-sectional view of (a) viewed from the right. It is a flowchart which shows the flow of the sand removal method. It is sectional drawing which cut at the center in the width direction of the sand basin of the 2nd Embodiment which has good sand movement efficiency. FIG. 7 is a cross-sectional view taken along the line DD of the sand basin shown in FIG. (A) is a cross-sectional view showing a modified example of the discharge port shown in FIG. 3, and (b) is a cross-sectional view taken along the line EE in (a). It is a figure which shows the deformation example of each of a groove forming body and a space forming member. It is a figure which shows the deformation example of each of a groove forming body and a space forming member. (A) is a cross-sectional view showing an example of the lower part of the sand basin in the sand basin, which has been devised to suppress the roll-up of sand while sufficiently moving the sand, and (b) is (a). It is a perspective view of the support member shown in).

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

FIG. 1 is a plan view of a sand basin with good sand movement efficiency as viewed from above, and FIG. 2 is a cross-sectional view taken along the line AA of the sand basin shown in FIG.

As shown in FIG. 1, the sand basin 1 is a rectangular pond in a plan view provided with a dust remover 2, a trough 3, a sand collecting pit 4, and a pump well 5. Hereinafter, the long side direction of the sand basin 1 may be referred to as a longitudinal direction, and the short side direction may be referred to as a width direction. The sand basin 1 shown in FIG. 1 receives sewage from the right side of the figure, and the received water slowly flows toward the left side of the figure (see the straight arrows shown in FIGS. 1 and 2). That is, the longitudinal direction of the sand basin is the direction of water flow, and in FIGS. 1 and 2, the right side of the figure is the upstream side of the water flow in the sand basin, and the left side is the downstream side. Further, water is discharged to the right side of FIGS. 1 and 2 from the 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 (residues) mixed in the sewage that has flowed into the sand basin 1, and is installed on the upstream side of the trough 3. The dust remover 2 has an endless chain 21, a plurality of rakes 22 attached to the endless chain 21 at intervals, and a filtration screen 23 submerged in water. The endless chain 21 is provided so as to stand diagonally on both sides of the sand basin 1 in the width direction, and is wound around the ground side sprocket 211 and the pond bottom side sprocket 212 as shown in FIG. There is. When the endless chain 21 is driven, the rake 22 goes in and out of the water. The filtration screen 23 is arranged on the downstream side of the endless chain 21. The filtration screen 23 has bars extending in the vertical direction arranged at predetermined intervals (for example, 25 mm to 75 mm) to block the passage of contaminants having a size equal to or larger than the predetermined intervals. The contaminants blocked by the filtration screen 23 are scraped up by the rake 22, and the contaminants that are scraped up are placed on a transportation means such as a belt conveyor (not shown) on the ground side.

On the downstream side of the dust remover 2, a sand collecting pit 4 for collecting sand accumulated in the lower part 1a of the pond is provided. A sand lifting pump 41 is provided inside the sand collecting pit 4. The sand pump 41 is arranged near the bottom surface of the sand collecting pit 4, and conveys the sand collected in the sand collecting pit 4 to the outside of the sand basin 1. A sand lifting pipe 42 is connected to the sand pump 41. The sand sucked by the sand lifting pump 41 is sent to the outside of the sand basin 1 through the sand lifting 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 on the downstream side of the sand collecting pit 4 and on the upstream side of the pump well 5. As will be described later, the trough 3 has a groove forming body 31 that forms a groove provided in the lower part 1a of the sand basin 1. The lower part of the pond 1a is provided with an inclined surface 6 as described later, and a trough 3 is provided so as to be connected to the inclined surface 6. The sand in the sewage that has flowed into the sand basin 1 settles toward the lower part 1a of the pond and accumulates in the lower part 1a of the pond.

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

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

Further, the trough 3 of the sand basin 1 shown in FIG. 1 includes a space forming member 32. 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 BB in FIG. In FIG. 3A, the left-right direction of the figure is the width direction of the trough 3.

FIG. 3A shows a lower portion of a pair of inclined surfaces 6 provided on the lower portion 1a of the pond, and a trough 3 provided so as to connect to the inclined surfaces 6. As shown in FIG. 3A, the inclined surfaces 6 are provided on both sides of the trough 3 in the width direction. The inclined surface 6 is made of concrete and is inclined downward toward the trough 3, and extends in the longitudinal direction between a position on the upstream side 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 arc 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 out a part of a pipe material such as stainless steel. The first arc-shaped member 3a is a portion (3/8) of a pipe material having a thickness of about 3 to 4 mm and a diameter of about 250 mm, which is pointed by the minute hand of a clock and is between 9 o'clock and 1 o'clock and 2 o'clock. It is a notch of an arc). The second arc-shaped member 3b is a part (3 / 3 /) of a pipe material having a thickness of about 3 to 4 mm and a diameter of about 150 mm, which is pointed by the minute hand of the clock and is between 4 o'clock and 5 o'clock to 9 o'clock. 8 arcs) are cut out. The trough 3 is formed by abutting and joining the end of the first arc-shaped member 3a corresponding to 9 o'clock to the end of the second arc-shaped member 3b corresponding to 9 o'clock. The space forming member 32 and the groove forming body 31 are formed by the first arc-shaped member 3a and the second arc-shaped member 3b.

The space forming member 32 and the groove forming body 31 will be described with reference to FIG. FIG. 4 is a diagram for conceptually explaining the space forming member and the groove forming body in the trough shown in FIG. FIG. (A) is a diagram showing a trough, FIG. (B) is a diagram showing a space forming member, and FIG. (C) is a diagram showing a groove forming body. In FIG. 4, the left-right 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 having a part in common with each other. In FIG. 4, the common portion 33 is painted and shown. In the common portion 33, a portion below the portion corresponding to 9 o'clock is formed by the first arc-shaped member 3a shown in FIG. 3 (a), and a portion above the portion corresponding to 9 o'clock is the first. 2 It is formed by an arcuate member 3b. Therefore, in the common portion 33, the portion below the portion corresponding to 9 o'clock has the curvature of the first arc-shaped member 3a, and the portion above the portion corresponding to 9 o'clock has a second arc shape. It becomes the curvature of the member 3b.

As shown in FIG. 4B, the space forming member 32 opens downward. Hereinafter, the portion that opens downward is referred to as a suction port 32a 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. 4A. The bottom 31a 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. The upper end portion 321 of the space forming member 32 is closed, but has an arc shape and is inclined downward. The space forming member 32 forms a space S2 in which a portion above the lower end is closed. The lower end portion of the space S2 connected to the suction port 32a becomes narrower as it approaches the suction port 32a.

As shown in FIG. 4C, the groove forming body 31 is open upward. Hereinafter, the left half of the groove forming body 31 in the width direction as shown in FIG. 4C is referred to as one end side of the groove forming body 31, and the right half of the groove forming body 31 in the width direction is the other than the groove forming body 31. Called the end side. As shown in FIG. 3A, the trough 3 is formed by joining the first arc-shaped member 3a and the second arc-shaped member 3b, but the groove-forming body 31 is formed on an inclined surface. It may be formed of 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 a common portion 33 in a state of being separated from the other end side of the groove forming body 31. As a result, the other end side of the groove forming body 31 and the space forming member 32 are opened upward. Hereinafter, the portion that opens upward is referred to as the opening 34 of the trough 3. Further, the space in the groove forming body 31 excluding the space S2 of the space forming member 32 is referred to as a space S1. That is, the space in which the space S1 and the space S2 are combined 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 32a is located below the opening of the groove.

As described above, since the space forming member 32 is connected to one end side in a state of being separated from the other end side of the groove forming body 31, the member supporting the space forming member 32 can be omitted. As a result, over the entire length of the trough 3, the member supporting the space forming member 32 does not hinder the sedimentation of sand into the groove, and the string-like contaminant is wrapped around the member supporting the space forming member 32. The problem of getting rid of is solved.

Further, as described above, the trough 3 of the present embodiment is formed by joining a first arc-shaped member 3a having a diameter of about 250 mm and a 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 to be about 100 mm over the entire length of the trough 3. Further, since the space forming member 32 and the groove forming body 31 have a common portion 33 which is partially shared with each other, it is easy to secure a gap W, and as a result, the size of the trough 3 in the width direction is suppressed. be able to. As described above, a filtration member (here, a 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 the length is longer than the maximum length of the contaminants (here, the mesh width of the screen is 75 mm) in order to prevent the contaminants that have passed through the filtration member on the upstream side from being clogged in the gap W. ..

As shown in FIG. 3A, one of the pair of inclined surfaces 6 (on the right side in FIG. 3A) has a lower end connected to the other end of the groove forming body 31 and is paired. The other of the inclined surfaces 6 (the 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 downward by 45 degrees, and the other inclined surface 6 is inclined downward by 42 degrees. The sand contained in the sewage that has flowed into the sand basin 1 settles in the lower pond 1a in the process of the sewage flowing downstream, but tends to accumulate in the lower pond 1a on the upstream side of the sand basin 1. Of the sand that has settled in the lower part of the pond 1a, the sand that has settled on the inclined surface 6 further flows down toward the trough 3 along the inclined surface 6. The sand that has flowed down from one of the inclined surfaces 6 enters the groove through the opening 34 of the trough 3. Further, the sand that has flowed down from the other inclined surface 6 passes through the arcuate side surface 322 of the space forming member 32 and enters the groove through 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 is less likely to remain at the connecting portion between the upper end portion 321 of the space forming member 32 and the other inclined surface 6. As a result, the sand that has settled in the lower part of the pond 1a is first collected at the bottom of the groove.

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

FIG. 3B is a cross-sectional view taken along the line CC in FIG. 3A. In FIG. 3B, the left-right direction of the figure is the extending direction of the trough 3, the right side of the figure is the upstream side (sand collection pit 4 side), and the left side is the downstream side (pump well 5 side).

As shown in FIGS. 3A and 3B, the water supply pipe 71 is arranged along the inclined surface 6 on the other side (left side in FIG. 3A), and the lower end portion is the upper end portion 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, a discharge port 7 for discharging a fluid is provided in the space S2 in which the water supply pipe 71 communicates. The discharge port 7 is formed by partitioning the upper portion of the space S2 in the space forming member 32 with a partition member 72. The partition member 72 includes a horizontal portion 721 extending horizontally in the extending direction of the trough 3 and an inclined portion 722 inclined upward from the end of the horizontal portion 721 on the downstream side (pump well 5 side). have. The horizontal portion 721 is connected to both sides in the width direction sandwiching the upper end portion on the inner peripheral surface of the space forming member 32, and the end portion on the upstream side (sand collection pit 4 side) thereof is closer than the lower end portion of the water supply pipe 71. It is located on the upstream side. Further, the inclined portion 722 has its downstream end connected to the downstream side of the inner peripheral surface of the space forming member 32 with respect to the portion to which the lower end portion of the water supply pipe 71 is connected, and connects the downstream side of the discharge port 7. It is blocked. As a result, the region in which the water supply pipe 71 communicates in the space S2 of the space forming member 32 is partitioned by the partition member 72. As described above, in the partition member 72, both ends of the horizontal portion 721 in the width direction are connected to the space forming member 32, and the downstream end portions of the inclined portion 722 are connected to the space forming member 32. Therefore, the partition member 72 is connected to the space forming member 32. The string-like contaminants are prevented from wrapping 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 on the most downstream side in the discharge direction, that is, at a position closest to the sand collection pit 4.

When water is discharged from the discharge port 7 into the space S2 of the space forming member 32, a pressure difference is generated between the inside (space S2) and the outside (space S1) of the space forming member 32 and is deposited on the bottom of the groove. The sand is sucked into the space S2 from the suction port 32a as shown by the curved arrow shown in FIG. 3A. Further, in the space S2 of the space forming member 32, the sucked sand moves toward the downstream side (sand collection pit 4 side) in the discharge direction by the flow of water discharged from the discharge port 7. As shown in FIG. 3A, the suction port 32a is an opening narrowed in the width direction (direction orthogonal to the extending direction of the space forming member 32), and the space S2 extends from the suction port 32a. It is a space. Since the suction port 32a is a narrowed opening, it is difficult for the sand moving in the space S2 to come out from the space S2, and the sand roll-up is further suppressed. In addition, it becomes easier to maintain the flow of water in the space S2, and the sand can be moved farther.

The structure of the discharge port 7 described above is the same for any of the discharge ports 7 connected to the water supply pipe 71. Further, 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 uppermost flow end portion of the trough 3 in the discharge direction is referred to as an upstream discharge port, and among the discharge ports 7 to which the water supply pipe 71 is connected shown in FIGS. 1 and 2, the sand collection pit 4 is used. The distant discharge port 7 may be referred to as an intermediate discharge port, and the discharge port 7 closer to the sand collection pit 4 may be referred to as a downstream discharge port (discharge port 7 shown in FIG. 3) to distinguish them. That is, the discharge port 7 provided on the upstream side of the trough 3 becomes the upstream discharge port, the discharge port 7 provided on the downstream side of the trough 3 becomes the downstream discharge port, and between the upstream discharge port and the downstream discharge port. The provided discharge port becomes an intermediate discharge port. When viewed from the sand basin shown in FIG. 1, the upstream discharge port is provided on the downstream side of the water flow in the sand basin, and the downstream discharge port is provided on the upstream side thereof. .. FIG. 5A is an enlarged partial cross-sectional view showing the vicinity of the most upstream end of the trough in the discharge direction. 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 in FIG. 5A, a plate-shaped upstream end face wall 36 is attached to the end face of the trough 3 which is the most upstream end in the discharge direction.

FIG. 5B is a partial cross-sectional view of FIG. 5A as viewed from the right. That is, FIG. 5B is a view of the upstream end face 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.

5 (a) and 5 (b) show an upstream discharge port 7 provided at the most upstream end of the trough 3 in the discharge direction. In the upstream discharge port 7, the inclined portion 722 in the partition member 72 of the downstream discharge port 7 (discharge port 7 shown in FIG. 3) is omitted, and the upstream end portion of the horizontal portion 721 in the discharge direction is connected to the upstream end face wall 36. Is formed. A flat, elongated hole-shaped discharge opening 36a is formed on the upstream end face wall 36 on the upstream side of the upstream discharge port 7 in the discharge direction. An L-shaped pipe 73 is connected to the upstream side of the discharge opening 36a in the discharge direction. The L-shaped pipe 73 is an L-shaped pipe in a plan view, and a supply pipe (not shown) for supplying water is connected to the L-shaped pipe 73. The water supplied from the supply officer is discharged from the discharge opening 36a to the downstream side in the discharge direction through the L-shaped pipe 73, and further discharged from the upstream discharge port 7 in the horizontal direction or in the substantially horizontal direction (FIG. 5A). See the arrow). 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 (the discharge port 7 shown in FIG. 3). You may.

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

According to the sand basin 1 of the present embodiment described above, it is possible to suppress the roll-up of sand while sufficiently moving the sand. In addition, the wrapping of string-like contaminants contained in sewage can be sufficiently suppressed.

Subsequently, a sand removing method for removing the sand accumulated in the lower part 1a of the sand basin 1 of the present embodiment from the sand basin 1 will be described.

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

When the sewage that has flowed into the sand basin 1 passes through the dust remover 2 shown in FIG. 2, the contaminants (residues) mixed in the sewage are removed. The sewage that has passed through the dust remover 2 crosses the sand collecting pit 4 and reaches the upstream end of the trough 3, and further flows in the extending direction of the trough 3. While the sewage flows through the upstream portion of the trough 3, most of the sand contained in the sewage settles in the lower part 1a of the sand basin 1. Some sand settles in the sand collecting pit 4, some sands settle on the inclined surface 6, and the sand settled on the inclined surface 6 further flows down toward the trough 3 along the inclined surface 6. Further, the sand that has settled down to the upper end portion 321 of the space forming member 32 flows down toward the bottom portion of the groove forming body 31 along the arcuate side surface 322 of the space forming member 32. In this way, sand accumulates in the ditch.

In the sand removing method of the present embodiment, first, the sand lifting pump 41 shown in FIGS. 1 and 2 is driven to remove the sand in the sand collecting pit 4 from the sand collecting pit 4 before carrying out the sand collecting step described later. (Step S1). The sand accumulated in the sand collecting pit 4 at this stage is mainly the sand that has settled in the sand collecting pit 4 and accumulated in the sand collecting pit 4 among the sand in the sewage that has flowed into the sand basin 1.

Next, with the sand pump 41 driven, 1500 liters of water per minute is discharged underwater for 3 minutes from only the downstream discharge port 7 shown in FIG. 3 out of 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. When water is discharged into the space S2 from the downstream discharge port 7, a pressure difference is generated between the inside (space S2) and the outside (space S1) of the space forming member 32, and the sand deposited on the upstream side portion in the groove. Is sucked into the space S2 from the suction port 32a (see the curved arrow 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 that moves in the space S2 of the space forming member 32 does not easily go out of the space forming member 32 at the portion where the pressure difference is generated, and the sand roll-up is suppressed. In this way, the sand deposited on the downstream side portion in the discharge direction in the groove moves in the space S2 of the space forming member 32 and eventually reaches the sand collecting pit 4. The sand that has reached the sand collecting pit 4 is conveyed to the outside of the sand basin 1 by the sand lifting pump 41 that started driving in the previous step S1, and the sand from the sand basin 1 is removed. The removal of sand here corresponds to an example of the discharge process.

Next, the discharge of water from the downstream discharge port 7 is stopped, and this time, 1500 liters of water per minute is discharged underwater for 3 minutes from only the intermediate discharge port 7 of the three discharge ports 7 (step S3). .. Even during the execution of step S3, the sand lifting pump 41 continues to be driven. In step S3 as well, as in step S2, by discharging water into the space S2 of the space forming member 32, 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 accumulated around the intermediate discharge port 7 in the groove is sucked into the space S2 again 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. Since the momentum of water from the intermediate discharge port 7 decreases around the downstream discharge port 7, 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. Once, it returns to the space S1 of the trough 3. That is, sand is deposited 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 1500 liters of water per minute is discharged again underwater for 3 minutes from only the downstream discharge port 7 shown in FIG. 3 in the same manner as in step S2 (similar to step S2). Step S4). Also in this step S4, the sand accumulated around the downstream discharge port 7 in the space S1 of the trough is sucked into the space S2 from the suction port 32a, and the sucked sand is sucked into the space S2 toward the sand collection pit 4. And eventually reach the sand collection pit 4. Even during the execution of step S4, the sand lifting pump 41 continues to be driven, and the sand that has reached the sand collecting pit 4 is removed from the sand basin 1 by the sand lifting pump 41. That is, the sand is also removed by the sand lifting pump 41, which corresponds to an example of the discharge process.

This time, the discharge of water from the downstream discharge port 7 is stopped, and 1500 liters of water per minute is discharged from only the upstream discharge port 7 of the three discharge ports 7 under water for 3 minutes (step S5). Even during the execution of step S5, the sand lifting pump 41 continues to be driven. In step S5 as well, as in steps S2 to S4, by discharging water into the space S2 of the space forming member 32, a pressure difference is generated between the inside (space S2) and the outside (space S1) of the space forming member 32. The sand accumulated 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. Further, the sucked sand moves in the space S2 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. Since the momentum of water from the upstream discharge port 7 decreases around the intermediate discharge port 7, the 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 accumulates 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 1500 liters of water per minute is discharged again underwater for 3 minutes from only the intermediate discharge port 7 in the same manner as in step S3 (step S6). Even during the execution of step S6, the sand lifting pump 41 continues to be driven. Also in step S6, the sand accumulated 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 moves into the space S2 toward the downstream discharge port 7. After moving, sand accumulates 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 1500 liters of water per minute is discharged underwater for 3 minutes from only the downstream discharge port 7 shown in FIG. 3 three times in the same manner as in step S2. (Step S7). Also in this step S7, the sand accumulated around the downstream discharge port 7 in the space S1 of the trough is sucked into the space S2 from the suction port 32a, and the sucked sand is sucked into the space S2 toward the sand collection pit 4. And eventually reach the sand collection pit 4. Even during the execution of step S7, the sand lifting pump 41 continues to be driven, and the sand that has reached the sand collecting pit 4 is removed from the sand basin 1 by the sand lifting pump 41. That is, the sand is also removed by the sand lifting pump 41, which corresponds to an example of the discharge process. Further, the sand pump 41 continues to be driven for a predetermined time even after the discharge of water from the downstream discharge port 7 is completed, and the removal of sand corresponding to an example of the discharge process is continuously performed.

In this way, the sand contained in the received water collects in the sand collecting pit 4 after being transferred into the space S2 of the space forming member 32 over six stages. Steps S2 to S7 described above correspond to the sand collecting step. This sand collection step does not need to be performed after draining the water in the sand basin 1 and reducing or eliminating all the water in the sand basin 1, and is carried out in a state where sewage is continuously received in the sand basin 1. As the fluid discharged from the discharge port 7 in the sand collecting step, the sewage received at the sewage treatment plant may be used, but other fluids may also be used.

Then, when the predetermined time elapses, the sand lifting pump 41 which started driving in step S1 is stopped (step S8), and when the predetermined time elapses or the sand that has settled accumulates sand in the sand collecting pit 4 to some extent. , Step S1 is carried out again. As described above, steps S1 to S8 are repeated after starting the acceptance of sewage.

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

According to the sand removing method of the present embodiment, the sand can be sufficiently moved in the sand basin 1 while suppressing the rolling up of the sand, and the sand can be removed from the sand basin 1. Further, in the sand removing method of the present embodiment, the sand is transferred from the downstream side to the upstream side so that the sand flows into the pump well 5 arranged on the most downstream side of the sand basin 1. Is being prevented. That is, in the present embodiment, a sand collecting point (sand collecting pit 4 in the present embodiment) is provided on the downstream side in the discharge direction, that is, the downstream side in the sand transfer direction (corresponding to the upstream side of the sand basin 1 in the present embodiment). A sewage discharge point (pump well 5 in this embodiment) is provided on the upstream side in the discharge direction, that is, on the upstream side in the sand transfer direction (corresponding to the downstream side of the sand basin 1 in this embodiment).

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

FIG. 7 is a cross-sectional view of the sand basin of the second embodiment, which has good sand movement efficiency, cut at the center in the width direction. Also in FIG. 7, the right side of the figure is the upstream side and the left side is the downstream side.

The sand basin 1 shown in FIG. 7 is different from the sand basin 1 shown in FIG. 1 in the position where the sand collecting pit 4 is provided. The sand basin 1 shown in FIG. 7 has an upstream trough 3 ′ on the upstream side of the sand collecting pit 4 and a downstream trough 3 ″ on the downstream side of the sand collecting pit 4. The total length of the upstream trough 3'is about 5 m, and the total length of the downstream trough 3'is about 10 m, which is twice that of the upstream trough 3'. The upstream trough 3'is provided with one discharge port 7 to which the water supply pipe 71 is connected at the upstream end portion, and the downstream trough 3'is provided with a discharge port 7 to which the water supply pipe 71 is connected. It is provided at each of the middle part and the downstream end part in the direction. 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 port 7 shown in FIG. 5 in the sand basin 1 of the first embodiment. A similar configuration may be used. Further, the same dust remover 2 as the dust remover 2 shown in FIG. 2 is installed on the upstream side of the upstream trough 3', but it is not shown in FIG. 7.

FIG. 8 is a DD cross-sectional view of the sand basin shown in FIG. In FIG. 8, the left-right direction of the figure is the width direction of the trough.

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

In the sand basin 1 of the second embodiment, the upstream trough 3'and the downstream trough 3'are arranged in the existing trough 83 from which the screw conveyor has been removed, and the inclined surface 6 is used by using the existing inclined surface 86. It is a pond that formed.

As shown in FIG. 8, in the sand basin 1 of the second embodiment, the downstream trough 3 ″ is arranged in each of the two existing troughs 83, and is located between the existing trough 83 and the downstream trough 3 ″. Concrete C has been cast. The two downstream troughs 3 ″ are arranged in a symmetrical state in the width direction so that the space forming members 32 are located outside in the width direction, and the upper end portion of each space forming member 32 has a width. The water supply pipe 71 indicated by the alternate long and short dash line is connected from the outside in the direction. Further, the cast concrete C forms a portion of the inclined surface 6 that connects the existing inclined surface 86 to the downstream trough 3 ″. The 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 structure of the inclined surface 6 connected to the downstream trough 3'' and the downstream trough 3'' described above is the same for the inclined surface 6 connected to the upstream trough 3'and the upstream trough 3'. ..

In the sand basin 1 of the second embodiment, an existing lower part of the pond having a trough on which a screw conveyor or the like is arranged can be used. The sand basin 1 of the first embodiment shown in FIG. 1 may also be a modified version of an existing pond lower part having a trough on which a screw conveyor or the like is arranged.

Next, a modification of the sand basin 1 described so far will be described focusing on points different from the configurations described so far. Further, in the drawings of the modified examples described below, the space forming member 32 and the groove forming body 31 are conceptually shown in the portion surrounded by the circle.

9 (a) is a cross-sectional view showing a modified example of the discharge port shown in FIG. 3, and FIG. 9 (b) is a cross-sectional view taken along the line EE in FIG. 3 (a). In FIG. 3A, the left-right direction of the figure is the width direction of the trough 3, and in FIG. 3B, the left-right direction of the figure is the extending direction of the trough 3.

The pond lower part 1a shown in FIG. 9 is different from the pond lower part 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 portion of the space forming member 32, the water supply pipe 71 is connected to the lid 323 from above, and a partition is provided on the lower surface of the lid 323. The member 72 is attached. A removable L-shaped joint 711 is provided at the tip 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 portion of the U-shaped portion 723, and both ends in the width direction of the U-shaped portion 723. The portion and the downstream end portion of the inclined portion 722 are fixed to the lower surface of the lid body 323 by welding or the like. The discharge port 7 is formed by the U-shaped portion 723 and the lid body 323.

In the pond lower part 1a shown in FIG. 9, after removing the L-shaped joint 711 from the water supply pipe 71, the discharge port 7 can be removed from the space forming member 32 together with the lid body 323 to perform maintenance of the discharge port 7. .. An opening may be provided in the vicinity of the portion of the space forming member 32 to which the partition member 72 is attached so that the discharge port 7 can be maintained by reaching out from the opening. The opening is closed by a removable lid, an openable and closable lid connected by a hinge or the like.

10 and 11 are views showing a modified example of the groove forming body and the space forming member. In FIGS. 10 and 11, the left-right direction of the figure is the width direction of the trough 3. In addition, in FIG. 10 and FIG. 11, the water supply pipe is omitted for the sake of simplification of the drawings.

The trough 3 shown in FIG. 10 (a) has a concrete groove forming body 31 having a U-shaped cross-sectional shape and a second trough 3 shown in FIG. 3 (a), as conceptually shown in the circle of the figure. It has a space forming member 32 having the same shape as the arc-shaped member 3b. The space forming member 32 is connected to an upper end portion (see the dotted line in FIG. 10A) on one end side of the groove forming body 31. As a result, 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. 10B includes a groove forming body 31 having a U-shaped cross-sectional shape and a part of the groove forming body 31 on one end side, as conceptually shown in the circle of the figure. It has a common space forming member 32. The common portion between the groove forming body 31 and the space forming member 32 corresponds to an intermediate portion in the vertical direction in the one end side portion of the groove forming body 31. That is, the space forming member 32 of this modification is provided in the groove and is connected to an intermediate portion in the vertical direction on one end side of the groove forming body 31. As a result, the space S2 of the space forming member 32 is located between the grooves formed by the groove forming body 31 in the vertical direction. Since the portion of the space forming member 32 protruding into the groove is curved downward in an arc shape, sand is less likely to accumulate on the space forming member 32.

The trough 3 shown in FIG. 11A has a groove forming body 31 having a U-shaped cross-sectional shape with an open upper part and a U-shaped structure with an open lower part, as conceptually shown in the circle of the figure. It has 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, a V-shaped cross section, or the like. Further, 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 may be used. ..

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 the trough 3 in the width direction from one end side end portion of the U-shaped portion 311. It has a horizontal portion 312 extending inward and a mounting portion 313 facing downward from the tip portion of the horizontal portion 312. The space forming member 32 has a cross-sectional shape of a 3/4 arc that opens downward. The upper end portion of the space forming member 32 is attached to the attachment portion 313 of the groove forming body 31. The space forming member 32 of this modification does not have a common portion common to a part of the groove forming body 31.

Also in the modified examples 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, it is possible to solve the problem that a string-like contaminant is wrapped around the member that supports the space forming member 32.

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, in the above embodiment, the space forming member 32 is provided over the entire length of the trough 3, but the space forming member 32 is within a range in which there is no risk of string-like contaminants contained in the received sewage being wrapped around. May be slightly shorter than the total length of the trough 3. In particular, when the total length of the trough 3 is long, the space forming member 32 may be divided in the extending direction of the trough 3 within a range in which there is no risk of string-like contaminants wrapping around. 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. Further, the discharge port 7 does not necessarily have to be installed in the space S2 of the space forming member 32, and is installed below the space forming member 32 (suction port 32a) and facing diagonally upward, so that the space forming member 32 is installed. The fluid may be discharged into the space S2 of the above.

It should be noted that even if the constituent requirements are included only in the description of each of the modified examples described above, the constituent requirements may be applied to other modified examples.

FIG. 12A is a cross-sectional view showing an example of the lower part of the sand basin in the sand basin, which is devised to prevent the sand from rolling up while sufficiently moving the sand.

The lower part 9 of the pond shown in FIG. 12A includes a trough 91 forming a groove, inclined surfaces 92 provided on both sides of the trough 91 in the width direction, 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 orthogonal to the paper surface is the extending direction of the trough 91, and the left-right direction in the figure is the width direction of the trough 91. The trough 91 is formed, for example, with 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 93a that is open downward and separated from the bottom of the trough 91. The discharge port 95 is arranged 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 front side of the paper surface is the downstream side in the discharge direction. become.

The support member 94 will be described with reference to FIG. 12B. FIG. 3B is a perspective view of the support member shown in FIG.

As shown in FIG. 12B, the support member 94 has a plate-shaped horizontal portion 941 and a plate-shaped vertical portion 942 fixed to the horizontal portion 941 by welding or the like. As shown in FIG. 6A, the support member 94 is installed so that the horizontal portion 941 closes the upper part of the trough 91. The support member 94 is formed so that the length of the horizontal portion 941 in the extending direction of the trough 91 is, for example, about 100 to 200 mm so as not to hinder the sedimentation of sand in the trough 91, and is several meters along the trough 91. Multiple installations are made every other time. 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 942a is formed in the vertical portion 942, and the space forming member 93 is fitted and fixed in the notch 942a. The vertical portion 942 is for preventing the wrapping of string-like contaminants (for example, hair or vinyl string) contained in the received sewage.

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

The sand basin described so far is a sand basin in which the sand contained in the received water settles in a ditch provided at the bottom of the pond.
A space forming member in which an upper end portion forms a closed space and a suction port is provided below the upper end portion and separated from the bottom of the groove.
A discharge port for discharging a fluid into the space is provided.
The suction port functions as an opening for sucking sand accumulated in the groove into the space by discharging a fluid from the discharge port.
The space forming member functions as a path for sand sucked into the space to move toward the downstream side in the discharge direction of the fluid when the fluid is discharged from the discharge port.
The lower part of the pond has a groove-forming body that forms the groove, and has a groove-forming body.
The space forming member is connected to the one end side of the groove forming body in a state of being separated from the other end side of the one end side and the other end side in the width direction orthogonal to the extending direction of the groove. It is characterized in that it is provided along the extending direction of the groove.

Here, the space forming member may be provided with a sufficient length and at intervals in the extending direction of the groove. It should be noted that the sufficient length referred to here may be longer than the length of the string-shaped contaminant that is usually considered.

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

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 the intermediate portion on the one end side in the vertical direction.

According to the sand basin, when the fluid is discharged into the space from the discharge port, a pressure difference is generated between the inside (the space) and the outside of the space forming member, and the sand accumulated in the lower part of the pond is generated. , It is sucked into the space from the suction port. Further, in the space, the sucked sand moves toward the downstream side in the discharge direction due to the flow of the fluid. The sand moving in the space is less likely to come out of the space forming member in the portion where the pressure difference is generated, and the rolling up of the sand is suppressed. Further, since the space forming member is connected to the one end side of the groove forming body in a state separated from the other end side and provided along the extending direction of the groove, the groove is formed. The sedimentation of sand can be received from between the other end side 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 wrapping of a long contaminant can be suppressed.

Further, in the sand basin, the space forming member is provided in the groove.
The suction port may be located below the opening of the groove.

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

Further, in the sand basin, a part of the space forming member may be shared with a part of the groove forming body.

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

Here, the space-forming member and the groove-forming body may each have an arcuate cross-sectional shape having a different curvature. In this case, the common portion between the space forming member and the groove forming body may have the curvature of the space forming member or the curvature of the groove forming body, and may form the space. A portion of the curvature of the member and a portion of the curvature of the groove forming body may be combined.

Further, in the sand basin, the space forming member may have an upper end portion formed of a curved surface.

By doing so, it is possible to prevent sand from accumulating on the space forming member.

Further, in the sand basin, the lower portion of the pond has a pair of inclined surfaces inclined downward toward the groove on both sides in the width direction of the groove.
One of the pair of inclined surfaces has a lower end portion connected to the other end side of the groove forming body.
The other of the pair of inclined surfaces may have a lower end portion connected to the upper end portion of the space forming member.

Since the lower end portion of one of the pair of inclined surfaces is connected to the other end side of the groove forming body, sand flows into the groove from the one inclined surface. 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 formed of a curved surface is formed from the other inclined surface. The sand that has flowed down to the upper end portion smoothly flows into the groove without accumulating in the upper end portion of the space forming member.

Further, in the sand basin, the space forming member may be connected to one end side over substantially the entire length of the groove.

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

In addition, in the above description,
A sand basin in which the sand contained in the received water settles in a ditch provided at the bottom of the pond.
A groove-forming body having a first arc-shaped portion that opens upward to form the groove,
It is provided with a space forming member that 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 a fluid into the space.
The space forming member functions as a path for sand sucked into the space to move toward the downstream side in the discharge direction of the fluid when the fluid is discharged into the space, and the groove. It is provided along the extending direction of the water, and has a second arc-shaped portion that opens downward and is smaller in the radial direction than the first arc-shaped portion.
The first arc-shaped portion and the second arc-shaped portion are connected to each other in the width direction orthogonal to the extending direction, so that the second arc-shaped portion is supported by the first arc-shaped portion, and the second arc-shaped portion is supported. A sand pond characterized in that the inner peripheral surface is composed of a continuous curved surface from the 1 arc-shaped portion to the 2nd arc-shaped portion.
Was explained.

Furthermore, in the above description,
A sand basin in which the sand contained in the received water settles in the trough groove provided at the bottom of the pond.
The trough is formed by a groove forming body that forms the groove and is open upward, and a space forming member that forms a closed space and is provided with a suction port connected to the space and extends along the groove. It is composed and
The suction port is a downward opening, and functions as an opening for sucking sand accumulated in the groove into the space by discharging a fluid into the space.
The space forming member functions as a path for sand sucked into the space to move toward the downstream side in the discharge direction of the fluid when the fluid is discharged into the space.
A sand basin characterized in that one end portion in the width direction orthogonal to the extending direction of the groove in the groove forming body and one end portion in the width direction in the space forming member are connected.
Was also explained.

Further, in this sand basin, the groove forming body may be composed of a plurality of planes extending in the extending direction.

Further, in the sand basin, the space may be narrowed as the portion on the suction port side approaches the suction port.

In addition, in the above description,
A sand basin in which the sand contained in the received water settles in a ditch extending toward the sand collection pit provided at the bottom of the pond.
A groove-forming body that opens upward to form the groove,
It is provided with a space forming member that 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 a fluid into the space.
The space forming member functions as a path for sand sucked into the space to move toward the sand collecting pit side by discharging the fluid into the space.
A sand basin characterized in that one end portion in the width direction orthogonal to the extending direction of the groove in the groove forming body and one end portion in the width direction in the space forming member are connected.
Was also explained.

In addition, in the above description,
It is a method of repairing a sand basin that has a groove that opens upward at the bottom of the pond.
It has an installation step of installing a space forming member having a space having a closed upper end portion and a suction port opened downward in the groove of the existing trough forming the groove.
When the fluid is discharged into the space, the sand accumulated in the groove is sucked into the space from the suction port, and the sand sucked into the space is moved to the downstream side in the discharge direction of the fluid. A renovation method characterized by renovating into a sand basin that moves toward.
Was also explained.

Furthermore, in the above description,
Repair of a sand basin that has a groove with a substantially U-shaped cross section that opens upward and has a pair of inclined surfaces that are inclined downward toward the groove on both sides in the width direction of the groove. It ’s a method,
It has an installation step of installing a space forming member having a space having a closed upper end portion and a suction port opened downward in the groove of the existing trough forming the groove.
When the fluid is discharged into the space, the sand accumulated in the groove is sucked into the space from the suction port, and the sand sucked into the space is moved to the downstream side in the discharge direction of the fluid. A method of repairing a sand basin, which is characterized by repairing a sand basin that is moved toward it.
Was also explained.

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

In addition, the repair method explained so far is
It is a method of repairing a sand basin that has a groove that opens upward at the bottom of the pond.
A removal process for removing the screw conveyor arranged in the groove, and
In the groove from which the screw conveyor has been removed, there is an installation step of installing a space forming member that extends along the groove, forms a space in which the upper end portion is closed, and is provided with a suction port that opens downward. death,
When the fluid is discharged into the space, the sand accumulated in the groove is sucked into the space from the suction port, and the sand sucked into the space is moved to the downstream side in the discharge direction of the fluid. It is characterized by renovation into a sand basin that moves toward.

Further, the installation step may be a step including installing a discharge port for discharging a fluid in the space.

In addition, the repair method explained so far is
Repair of a sand basin that has a groove with a substantially U-shaped cross section that opens upward and has a pair of inclined surfaces that are inclined downward toward the groove on both sides in the width direction of the groove. It ’s a method,
A removal process for removing the screw conveyor arranged in the groove, and
In the groove from which the screw conveyor has been removed, there is an installation step of installing a space forming member that extends along the groove, forms a space in which the upper end portion is closed, and is provided with a suction port that opens downward. death,
When the fluid is discharged into the space, the sand accumulated in the groove is sucked into the space from the suction port, and the sand sucked into the space is moved to the downstream side in the discharge direction of the fluid. It is characterized by renovation into a sand basin that moves toward.

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

Further, the installation step may be a step including installing a discharge port for discharging a fluid in the space.

Further, the installation process may include arranging a water supply pipe connected to the discharge port on one of the pair of inclined surfaces.

In addition, the installation step may include connecting the water supply pipe connected to the discharge port to the upper end portion of the space forming member.
In addition, in the above description,
A sand basin in which the sand contained in the received water settles in a ditch extending toward the sand collection pit provided at the bottom of the pond.
A groove-forming body that opens upward to form the groove,
A space-forming member that forms a closed space, is provided with a suction port connected to the space, and extends along the groove.
A sand basin provided with a support member for supporting the space forming member.
Was also explained.
Further, here, the support member may support the outer peripheral surface of the space forming member.

1 Sand basin 1a Pond lower part 3 Trough 31 Groove forming body 32 Space forming member 321 Upper end part 33 Common part 34 Opening 4 Sand collecting pit 6 Inclined surface 7 Discharge port S1, S2 Space

Claims (2)

A sand basin in which the sand contained in the received water settles in a ditch extending toward the sand collection pit provided at the bottom of the pond.
A groove-forming body that opens upward to form the groove,
A space-forming member that forms a closed space, is provided with a suction port connected to the space, and extends along the groove.
A discharge port arranged in the space and discharging a fluid into the space,
A support member for supporting the space forming member is provided .
The support member is a sand basin that supports the outer peripheral surface of the space forming member. The sand basin according to claim 1, wherein the support member is interposed between the space forming member and the groove forming body.

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