JP6900061B2 - Transport system - Google Patents

Description

The present invention relates to a transfer system in which contaminants contained in a received liquid settle.

The sewage treatment system receives sewage such as sewage or rainwater, sediments the sand contained in the sewage to the bottom of the pond, and then moves it in a predetermined direction to collect the sand accumulated at the bottom of the pond. Some have sand basins that remove sand from sewage. It is known that this sand basin is provided with a sand collecting means for moving the sand accumulated 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. In sand collection using this fluid, the accumulated sand may be sprinkled by the discharged fluid, and it is important how to suppress the sprinkling of sand. Conventionally, inclined plates inclined downward toward the downstream side in the discharge direction are arranged above the bottom of the pond at intervals along the discharge direction, and the inclined plates are used to prevent sand from being scattered ( For example, refer to Patent Document 1 and the like).

In addition, the sewage treatment system receives water from which sand has been removed from the sand basin, settles the sludge contained in the received water to the bottom of the pond, and then collects the sludge accumulated at the bottom of the pond in a predetermined direction. Some have a settling basin that removes the collected sludge from the sewage. It is also known that this settling basin is provided with a moving means for moving the sludge accumulated at the bottom of the basin toward the downstream side in the discharge direction of the fluid by the flow of the fluid discharged from the discharge port. Since sludge has a smaller particle size than sand, it is easier to sprinkle than sand, and how to suppress the sprinkling of sludge becomes more important. Conventionally, a shield plate inclined downward toward the downstream side in the discharge direction is provided above the discharge nozzle provided at the bottom of the settling basin, and the shield plate is used to prevent sand from being scattered (for example, a patent). Refer to Reference 2 etc.).

Japanese Unexamined Patent Publication No. 9-70503 Jikkai Sho 64-56807

However, in the inclined plate described in Patent Document 1, the inclined plate is arranged so as to face the discharge direction, the fluid discharged from the discharge port is blocked, and the sand may not move sufficiently. is there. Therefore, if the discharge pressure of the discharge port is increased in an attempt to move the sand sufficiently, the sand may be scattered along the inclined plate due to the force of the discharged fluid.

Further, also in the shielding plate described in Patent Document 2, the shielding plate is arranged so as to face the discharge direction, and there is the same problem as in Patent Document 1.

Furthermore, in addition to sand basins and sedimentation basins, for example, it is conceivable to move contaminants such as sediment that have flowed into a reservoir such as a dam lake in one direction and discharge the collected contaminants such as sediment. Also, it is preferable to suppress the sprinkling of contaminants such as earth and sand accumulated on the bottom of the dam lake and move them.

In view of the above circumstances, it is an object of the present invention to provide a transfer system devised to suppress the sprinkling of contaminants while sufficiently moving the contaminants.

The transfer system of the present invention that solves the above object is a transfer system in which contaminants contained in the received liquid settle to the bottom.
A space-forming member extending along the bottom portion, forming a space in which the upper end portion is closed, and having an opening separated from the bottom portion below the upper end portion.
A discharge port for discharging a fluid into the space is provided.
The discharge port has a flat shape and is formed by partitioning the upper portion of the space with a partition member, and discharges a fluid toward the downstream side in the transfer direction of the contaminant. And.
Further, in this transfer system, the contaminants contained in the received liquid settle to the bottom, which is a transfer system.
A space-forming member extending along the bottom portion, forming a space in which the upper end portion is closed, and having an opening separated from the bottom portion below the upper end portion.
A discharge port for discharging a fluid into the space is provided.
The discharge port may have a flat shape and may be located above the opening and discharge the fluid toward the downstream side in the transfer direction of the contaminant.

In addition, it is a transfer system in which contaminants contained in the received liquid settle to the bottom.
A space-forming member extending along the bottom portion, forming a space in which the upper end portion is closed, and having an opening separated from the bottom portion below the upper end portion.
A discharge port for discharging a fluid into the space is provided.
The space is such that the lower end portion connected to the opening becomes narrower as it approaches the opening.
The discharge port may discharge the fluid toward the downstream side in the transfer direction of the contaminant.

In addition, it is a transfer system in which contaminants contained in the received liquid settle to the bottom.
A space-forming member extending along the bottom portion, forming a space in which the upper end portion is closed, and having an opening separated from the bottom portion below the upper end portion.
A discharge port for discharging a fluid into the space is provided.
The space may be such that the lower end portion connected to the opening becomes narrower as it approaches the opening.

In addition, it is a transfer system in which contaminants contained in the received liquid settle to the bottom.
A space-forming member extending along the bottom portion, forming a space in which the upper end portion is closed, and having a suction port separated from the bottom portion below the upper end portion.
A discharge port for discharging a fluid into the space is provided.
The suction port functions as an opening for sucking the contaminants accumulated on the bottom into the space due to the pressure difference between the inside of the space and the outside of the space, which is generated by discharging the fluid from the discharge port. And
The space forming member functions as a path for the contaminants 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 space may be a transfer system characterized in that the lower end portion connected to the suction port becomes narrower as it approaches the suction port.

Further, in this transfer system, the discharge port may have a flat shape.

In addition, it is a transfer system in which contaminants contained in the received liquid settle to the bottom.
A space-forming member extending along the bottom portion, forming a space in which the upper end portion is closed, and having a suction port separated from the bottom portion below the upper end portion.
A discharge port for discharging a fluid into the space is provided.
The suction port functions as an opening for sucking the contaminants accumulated on the bottom into the space due to the pressure difference between the inside of the space and the outside of the space, which is generated by discharging the fluid from the discharge port. And
The space forming member functions as a path for the contaminants 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 discharge port may have a flat shape.

Further, in this transfer system, the discharge port may discharge a fluid in a horizontal direction or a substantially horizontal direction.

Further, in this transfer system, the discharge port may be located below the center of the space forming member and above the suction port.

Also, in this transfer system, a groove formed at the bottom thereof and opening upward is provided.
The suction port opens in the groove and functions as an opening for sucking the contaminants accumulated in the groove into the space by discharging the fluid from the discharge port.
The discharge port may be one that discharges the fluid into the space instead of discharging the fluid toward the contaminants that are inside the groove and are accumulated outside the space.

Further, in this transfer system, the discharge port may be located below the center of the groove.

In addition, it is a transfer system in which contaminants contained in the received liquid settle to the bottom.
A space-forming member extending along the bottom portion, forming a space in which the upper end portion is closed, and having a suction port separated from the bottom portion below the upper end portion.
A discharge port for discharging a fluid into the space is provided.
The suction port functions as an opening for sucking the contaminants accumulated on the bottom into the space by discharging the fluid from the discharge port.
The space forming member functions as a path for the contaminants 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 suction port has a lower end of the space forming member opened downward.
The space may be such that the lower end portion connected to the suction port becomes narrower as it approaches the suction port.

Further, in this transfer system, the discharge port may be located below the center of the space forming member and above the suction port.

Further, in this transfer system, the discharge port may have a flat shape.

Further, in this transfer system, the bottom portion has a groove formed therein.
In the space forming member, the suction port is opened in the groove, and the height position of the upper end portion is located at substantially the same height as the opening of the groove or below the opening of the groove. May be good.

Further, in this transfer system, the bottom portion has a groove formed therein.
The groove has a shape in which the upper part of the cylindrical body is cut out.
The space forming member may have a shape in which the suction port opens in the groove and the lower part of the cylindrical body is cut out.

In addition, it is a sand basin where the sand contained in the received water settles at the bottom of the pond.
A space-forming member extending along the bottom of the pond, forming a space in which the upper end is closed, and having a suction port separated from the bottom of the pond below the upper end.
A discharge port for discharging a fluid into the space is provided.
The suction port functions as an opening for sucking sand accumulated on the bottom of the pond 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 discharge port may be a sand basin characterized in that the fluid is discharged at a flow rate of 8 m / sec or more.

Further, the discharge port may discharge the fluid at a discharge pressure of 0.05 MPa or more and 0.3 MPa or less.

Further, the discharge port may be located below the center of the space forming member and above the suction port.

Further, the discharge port may have a flat shape.

Further, the bottom of the pond has a groove formed therein.
In the space forming member, the suction port is opened in the groove, and the height position of the upper end portion is located at substantially the same height as the opening of the groove or below the opening of the groove. May be good.

Further, the bottom of the pond has a groove formed therein.
The groove has a shape in which the upper part of the cylindrical body is cut out.
The space forming member may have a shape in which the suction port opens in the groove and the lower part of the cylindrical body is cut out.

Further, the suction port has a lower end of the space forming member opened downward.
The space may be such that the lower end portion connected to the suction port becomes narrower as it approaches the suction port.

In addition, the sand contained in the received water is a sand basin that settles at the bottom of the pond.
A space-forming member that extends along the bottom of the pond and has a closed space at the upper end and a suction port separated from the bottom of the pond below the upper end.
Equipped with a discharge port that discharges fluid into the above space
The suction port functions as an opening for sucking sand accumulated on the bottom of the pond into the space by discharging a fluid from the discharge port.
The space forming member is characterized in that the sand sucked into the space functions as a path for the fluid to move toward the downstream side in the discharge direction when the fluid is discharged from the discharge port. It may be a sand basin.

Here, the space forming member may have a C-shaped (arc-shaped), U-shaped, V-shaped, U-shaped, or the like in cross section, and further, the suction port is along the bottom of the pond. It may be a plurality of tubular ones. Alternatively, the suction port may have a slit shape extending along the bottom of the pond.

Further, the space forming member itself may be in contact with the bottom of the pond or may be separated from the bottom of the pond.

Further, the space forming member may have the suction port provided in the lower portion.

According to this sand basin, when a 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 on the bottom of the pond is deposited. , 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 sprinkling of sand is suppressed. Therefore, according to this sand basin, it is possible to suppress the sprinkling of sand while sufficiently moving the sand.

Further, in this sand basin, the suction port has a lower end of the space forming member opened downward.
The space may be narrower as the lower end portion connected to the suction port approaches the suction port.

That is, the suction port may be an opening narrowed in the width direction orthogonal to the extending direction of the space forming member, and the space may be a space extending from the suction port. By having the suction port narrowed in this way, it becomes difficult for the sand moving in the space to come out from the space, and the sprinkling of sand is further suppressed. In addition, it becomes easier to maintain the flow of the fluid in the space, and the sand can be moved farther.

The suction port may extend along the bottom of the pond.

Further, the space forming member may have an arc shape having a cross-sectional shape larger than 1/2 (for example, a 3/4 arc shape).

Further, in this sand basin, the discharge port may be arranged in the space, and the discharge port may be in the direction in which the space forming member extends, that is, with the space forming member. The fluid may be discharged in a parallel direction (for example, a horizontal direction).

By doing so, the pressure difference is more likely to occur.

Here, the closer to the discharge port, the faster the velocity of the fluid, that is, the flow velocity. Therefore, by arranging the discharge port in the space and in the vicinity of the suction port, sand can be more easily sucked from the suction port.

Further, in this sand basin, a groove is formed at the bottom of the pond.
The space forming member may have a mode in which the suction port is opened in the groove.

According to this aspect, the sand deposited on the bottom of the pond can be efficiently sucked into the space, and the sand collection efficiency is improved.

The groove may have an arcuate cross-sectional shape, and in this case, an arcuate shape larger than 1/2 (for example, a 3/4 arcuate shape) is preferable. By doing so, it is possible to further prevent the sand accumulated in the groove from being scattered outside the groove.

In addition, in a sand basin where the sand contained in the received water settles at the bottom of the pond, this is a sand removal method for removing the sand accumulated at the bottom of the pond from the sand basin.
A fluid in a space-forming member extending along the bottom of the pond and having a closed space at the upper end and a suction port separated from the bottom of the pond below the upper end. And the sand collection process that moves the sand accumulated on the bottom of the pond toward the downstream side in the discharge direction of the fluid.
It has a discharge step of discharging sand that has moved downstream in the discharge direction to the outside of the sand basin by carrying out the sand collection step.
In the sand collecting step, by discharging the fluid into the space, the sand accumulated at the bottom of the pond is sucked into the space from the suction port, and the sand sucked into the space is directed to the downstream side in the discharge direction. The sand removal method may be characterized in that it is a step of moving the sand.

According to this sand removal method, the sand can be sufficiently moved in the sand basin while suppressing the sprinkling of sand, and the sand can be removed from the sand basin.

In addition, it is a transfer system that moves the contaminants in one direction at the bottom where the contaminants contained in the received liquid have settled.
A space forming member in which an upper end portion forms a closed space and a suction port separated from the bottom portion is provided below the upper end portion.
Fluid supply pipe and
It is provided with a discharge port for discharging the fluid supplied by the fluid supply pipe into the space.
The suction port functions as an opening for sucking the contaminants accumulated on the bottom into the space by discharging the fluid from the discharge port.
The space forming member is characterized in that the contaminants sucked into the space function as a path for the fluid to move toward the downstream side in the discharge direction when the fluid is discharged from the discharge port. It may be a transport system.

Here, the transfer system is provided in the dam lake, and may move the sediment settled at the bottom of the dam lake in one direction. Further, the transfer system may move metal powder generated in a factory or the like in one direction. The received liquid may be stopped and retained for the time required to settle the contaminants, or may be allowed to flow and retained at the flow rate required to settle the contaminants.

According to this transfer system, 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 contaminants accumulated on the bottom are generated. , It is sucked into the space from the suction port. Further, in the space, the sucked contaminants move toward the downstream side in the discharge direction due to the flow of the fluid. The contaminants moving in the space are less likely to come out of the space-forming member in the portion where the pressure difference is generated, and the sprinkling of the contaminants is suppressed. Therefore, according to this transfer system, it is possible to suppress the sprinkling of the contaminant while sufficiently moving the contaminant.

Further, in the transfer system, the suction port is provided in a sedimentation basin where sludge settles.
It may function as an opening for sucking sludge deposited as a contaminant at the bottom of the sedimentation basin into the space.

Here, the bottom portion may be the bottom portion of the sedimentation basin, or may be the bottom portion of a transfer path provided on the upstream side of the bottom portion of the pond and connected to the sludge pit.

Further, it is a method for removing contaminants, which is a method for removing contaminants accumulated on the bottom where the contaminants contained in the received liquid have settled.
A fluid is discharged into the space in a space forming member that extends along the bottom portion and has a space in which the upper end portion is closed and has a suction port separated from the bottom portion below the upper end portion. Then, a moving step of moving the contaminants deposited on the bottom toward the downstream side in the discharge direction of the fluid, and
It has a discharge step of discharging the contaminants that have moved to the downstream side in the discharge direction by carrying out the movement step.
In the moving step, by discharging the fluid into the space, the contaminants deposited on the bottom of the space are sucked from the suction port, and the contaminants sucked into the space are directed to the downstream side in the discharge direction. The method may be a method for removing contaminants, which is characterized by a step of moving the mixture.

Here, the contaminant may be sludge, earth and sand, or metal powder. The received liquid may be stopped and retained for the time required to settle the contaminants, or may be allowed to flow and retained at the flow rate required to settle the contaminants.

According to this method for removing contaminants, it is possible to remove the contaminants by sufficiently moving the contaminants while suppressing the sprinkling of the contaminants.

According to the present invention, it is possible to provide a transfer system devised to suppress the sprinkling of contaminants while sufficiently moving the contaminants.

It is a top view of the sand basin corresponding to one embodiment of the present invention. FIG. 5 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. (A) is a partial cross-sectional view showing the vicinity of the most upstream end of the trough in an enlarged manner, and (b) is a partial cross-sectional view of FIG. 4 (a) viewed from the right. It is a flowchart which shows the flow of the sand removal method. It is sectional drawing which cut | cut the sand basin of 2nd Embodiment in the center in the width direction. FIG. 6 is a cross-sectional view taken along the line DD of the sand basin shown in FIG. This It is a perspective view which shows the modification of the space forming member. It is a figure which shows the modification of the discharge port. It is a figure which shows the modification of the way of supporting a space forming member. It is a top view of the settling basin provided with one embodiment of the transfer system. It is a side sectional view of the settling basin shown in FIG. FIG. 12 is a cross-sectional view taken along the line EE in FIG. (A) is an enlarged view showing the G part of FIG. 13 in an enlarged manner, and (b) is an enlarged view showing the H part of FIG. 13 in an enlarged manner. It is a flowchart which shows the flow of the sludge removal method. It is sectional drawing which shows the aspect corresponding to FIG. 13 in the settling basin provided with the transfer system of 2nd Embodiment. (A) is an enlarged view showing part I of FIG. 16 in an enlarged manner, and (b) is a sectional view taken along line JJ in (a). It is a top view of the settling basin provided with the third embodiment of the transfer system. It is a KK cross-sectional view of the settling basin shown in FIG. It is a cross-sectional view of LL of the settling basin shown in FIG. It is a flowchart which shows the flow of the 2nd sludge removal method. It is a figure which shows the modification of the way of supporting a space forming member. It is a figure which shows the modification which installed the space forming member 28 shown in FIG. 13 movably in the width direction.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The sand basin according to the embodiment of the present invention is arranged 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. It removes from sewage.

FIG. 1 is a plan view of a sand basin corresponding to an embodiment of the present invention 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 and the left side is the downstream side.

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 on the bottom 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. The trough 3 is a groove provided in the bottom portion 1a (see FIG. 2) of the sand basin 1. The bottom portion 1a of the pond 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 bottom 1a of the pond and accumulates on the bottom 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 (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 a 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 a groove provided in the center of the sand basin 1 in the width direction and extending in a predetermined direction from a position upstream of the pump well 5. That is, it extends toward the sand collecting pit 4. The downstream 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 sand basin 1 shown in FIG. 1 also includes a space forming member 8 in the trough 3. The total length of the space forming member 8 is the same as the total length of the trough 3, and the space forming member 8 extends along the trough 3. A detailed description of the space forming member 8 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 an inclined surface 6 provided on the bottom of the pond 1a and a trough 3 provided so as to connect to the inclined surface 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 45 degrees 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. There is. The inclination angle of the inclined surface 6 may be, for example, 30 degrees or 60 degrees.

Further, as shown in FIG. 3A, the trough 3 is a groove having a cross-sectional shape of a 3/4 arc and having a total length of about 15 m. The trough 3 is formed by bending a plate material such as stainless steel, but may be formed of concrete integrally with the inclined surface 6. Further, the cross-sectional shape of the trough 3 is not limited to the arc shape, and may be a U shape, a V shape, or the like. The trough 3 shown in FIG. 3A has a shape in which an upper (liquid level side) 1/4 of a cylindrical body having a diameter of about 356 mm is cut out, and is open upward. Hereinafter, the portion that opens upward is referred to as the opening 3a of the trough 3. Of the space S1 in the trough 3, the upper end portion 3b connected to the upper end opening 3a becomes narrower as it approaches the opening 3a. That is, the opening 3a of the trough 3 is an opening narrowed in the width direction orthogonal to the extending direction of the trough.

The sand contained in the sewage that has flowed into the sand basin 1 settles in the pond bottom 1a in the process of the sewage flowing downstream, but tends to accumulate in the pond bottom 1a on the upstream side of the sand basin 1. Of the sand that has settled on the bottom of the pond 1a, the sand that has settled on the inclined surface 6 flows down further toward the trough 3 along the inclined surface 6 and enters the inside of the trough through the opening 3a of the trough 3. Therefore, the sand that has settled on the bottom 1a of the pond is first collected in the trough 3.

The space forming member 8 shown in FIG. 3A has a cross-sectional shape of a 3/4 arc. The space forming member 8 is formed by molding a stainless steel plate having a plate thickness of 4 mm into an arc-shaped cross section. The space forming member 8 shown in FIG. 3A has a shape in which the lower part (the pond bottom side) 1/4 of the cylindrical body having a diameter of about 156 mm is cut out, and is open downward. That is, the lower end of the space forming member 8 is opened downward, and hereinafter, this open portion is referred to as a suction port 81. The suction port 81 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 inner peripheral wall of the trough 3. The space forming member 8 partitions the space in the trough 3 and forms a space S2 in which a portion above the lower end is closed. The upper end portion 82 of the space forming member 8 is closed, but has an arc shape and is inclined downward. Sand also settles on the space forming member 8, but since it is arcuate, it is difficult for sand to accumulate, and the sand that has settled on the space forming member 8 runs along the arcuate side surface 80 and troughs 3. It becomes easy to flow down toward the bottom 31 of the. Further, due to the arcuate side surface 80, the space S2 becomes narrower as the lower end portion connected to the suction port 81 approaches the suction port 81.

Here, as shown in FIGS. 1 and 2, a support plate member 91 is bridged over the upper end of the trough 3 in the width direction of the trough 3 at intervals of about 5 m. Both ends of the support plate member 91 are fixed to the inclined surface 6, and at the place where the support plate member 91 is installed, the opening 3a of the trough 3 is covered by the support plate member 91, but the support plate member 91 However, the length in the trough extending direction is about 200 mm, and the accumulation of sand on the support plate member 91 is not a problem. Further, the length of about 200 mm greatly reduces the risk of string-like contaminants (for example, hair or vinyl string) wrapping around the support plate member 91.

In the space forming member 8 shown in FIG. 3A, the upper end portion 82 is supported by the support plate member 91. Therefore, the height position of the upper end portion 82 of the space forming member 8 is substantially the same as the height position of the opening 3a of the trough 3. In the present embodiment, when viewed in the height (depth) direction, the radial center of the space forming member 8 is displaced upward from the radial center 3c of the trough 3, but the trough 3 Seen in the width direction, the radial center of the space forming member 8 coincides with the radial center 3c of the trough 3. Therefore, the gap W between the trough 3 and the space forming member 8 is secured to be 80 mm or more even at the narrowest position. As described above, a filtration member (here, a filtration screen 23) is installed on the upstream side, and the gap W between the trough 3 and the space forming member 8 is the maximum length of the contaminant that passes through the filtration member (here). Then, it is preferable that the width of the screen is longer than 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.

Further, the space S2 in the space forming member 8 is provided with a discharge port 7 for discharging a fluid in the space S2. The discharge port 7 has an elongated hole shape in which the tip of a pipe-shaped water supply pipe 71 having a diameter of less than 50 mm is flattened. The maximum opening length of the discharge port 7 in the lateral direction (trough width direction) is about 60 mm or less. By forming the discharge port 7 in such a flat shape, it is possible to secure a wider range in which the flow velocity is increased than in the case of a perfect circle shape. The water supply pipe 71 penetrates the inclined plate 6 from the back side of the inclined plate 6, extends along the support plate member 91 in the width direction of the trough 3, and bends downward at the center of the width direction of the trough 3, and this time. Penetrates the support plate member 91 and the space forming member 8 and enters the space S2.

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). Further, the axial center 8c of the space forming member 8 passing through the radial center of the space forming member 8 is indicated by a alternate long and short dash line.

The portion 711 of the water supply pipe 71 that has entered the space S2 extends downward beyond the radial center of the space forming member 8 and is above the radial center 3c of the trough 3 (see FIG. 3A). It bends horizontally toward the upstream side (sand collection pit 4 side). That is, a rectangular wrapping prevention plate 95 is erected at the upper end of the space forming member 8, and the portion 711 of the water supply pipe 71 that has entered the space S2 is the vertical edge of the wrapping prevention plate 95. It extends downward along 951 and then upstream along the lateral edge 952 of the wrapping prevention plate 95. The wrapping prevention plate 95 prevents the string-like contaminants from wrapping around the portion 711 of the water supply pipe 71 that has entered the space S2. The portion of the water supply pipe 71 extending to the upstream side extends beyond the wrapping prevention plate 95, and the discharge port 7 is located on the upstream side of the wrapping prevention plate 95.

The discharge port 7 of the present embodiment is located below the radial center of the space forming member 8 and above the suction port 81. Water is discharged from the discharge port 7 in parallel with or substantially parallel to the axis 8c of the space forming member 8. That is, water is discharged in the horizontal direction or in the substantially horizontal direction (see the arrow pointing to the right in FIG. 3B).

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

When water is discharged from the discharge port 7 into the space 2 of the space forming member 8, a pressure difference is generated between the inside (space S2) and the outside of the space forming member 8 and is deposited in the trough 3 (space S1). The sand is sucked into the space S2 from the suction port 81 as shown by the curved arrow shown in FIG. 3A. Further, in the space S2 of the space forming member 8, the sucked sand moves toward the sand collecting pit 4 side by the flow of water discharged from the discharge port 7. As shown in FIG. 3, the suction port 81 is an opening narrowed in the width direction (direction orthogonal to the extending direction of the space forming member 8), and the space S2 is a space extending from the suction port 81. .. Since the suction port 81 is an opening narrowed in this way, it becomes difficult for sand moving in the space S2 to go out from the space S2, and the sprinkling of sand 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 in the support plate member 91 described above is the same for any of the support plate members 91 provided at the upper end of the trough 3. The discharge port 7 is also provided on the downstream end face wall 36 of the trough 3. Hereinafter, the discharge port 7 provided on the downstream end face wall 36 of the trough 3 is referred to as a downstream discharge port, and the discharge port 7 in the support plate member 91 on the downstream side shown in FIGS. 1 and 2 is referred to as an intermediate discharge port, and is referred to as an intermediate discharge port. The discharge port 7 (discharge port 7 shown in FIG. 3) in the support plate member 91 of the above may be referred to as an upstream discharge port to distinguish them.

FIG. 4A is an enlarged partial cross-sectional view showing the vicinity of the most upstream end of the trough. In FIG. 4A, the right side of the figure is the upstream side, and the left side of the figure is the downstream side.

As shown in FIG. 4A, a plate-shaped downstream end face wall 36 is attached to the end face which is the most downstream end of the trough 3.

FIG. 4B is a partial cross-sectional view of FIG. 4A as viewed from the right. That is, FIG. 4B is a view of the downstream end face wall 36 as viewed from the upstream side, and the back side of the paper surface is the downstream side.

FIG. 4B shows a downstream discharge port 7 provided on the downstream end face wall 36. An L-shaped pipe 77 that forms a vacant room 78 (see FIG. (A)) connected to the downstream discharge port 7 is provided further downstream than the downstream discharge port 7. The L-shaped pipe 77 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 77. The direction of the flow of the water flowing into the vacant room 78 changes to the downstream side in the vacant room 78, and the water is discharged horizontally or substantially horizontally from the downstream discharge port 7. The position in the trough width direction in which the downstream discharge port 7 is provided is the same as the position in the trough width direction in which the discharge port 7 is provided as shown in FIG. Further, the height position where the downstream discharge port 7 is provided is also the same as the height position where the discharge port 7 shown in FIG. 3 is provided.

The sand basin 1 of the present embodiment is provided with three discharge ports 7 of a downstream discharge port, an intermediate discharge port, and an upstream discharge port, and the water discharge flow velocity at any of the discharge ports 7 is 8 m / sec. The above is preferable. 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 equipment 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 sprinkling of sand while sufficiently moving the sand.

Subsequently, a sand removing method for removing the sand accumulated on the bottom 1a of the sand basin 1 of the present embodiment from the sand basin 1 will be described.

FIG. 5 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 sinks to the bottom 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 82 of the space forming member 8 flows down toward the bottom portion 31 of the trough 3 along the arcuate side surface 80 of the space forming member 8. In this way, sand is deposited in the space S1 of the trough 3.

In the sand removing method in 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 upstream discharge port 7 shown in FIG. 3 out of the three discharge ports 7 (step S2). .. In this step S2, water is discharged from the space S1 of the trough 3 into the space S2 partitioned by the space forming member 8. When water is discharged into the space 2 from the upstream discharge port 7, a pressure difference is generated between the inside (space S2) and the outside of the space forming member 8 and is deposited on the upstream side portion in the trough 3 (space S1). The sand is sucked into the space S2 from the suction port 81 (see the curved arrow shown in FIG. 3A). Further, in the space S2 of the space forming member 8, the sucked sand moves toward the sand collecting pit 4 by the flow of water discharged from the upstream discharge port 7. The sand moving in the space S2 of the space forming member 8 is hard to come out of the space forming member 8 at the portion where the pressure difference is generated, and the sprinkling of sand is suppressed. In this way, the sand deposited on the upstream side portion of the trough 3 moves in the space S2 of the space forming member 8 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 this discharge step.

Next, the discharge of water from the upstream 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 8, a pressure difference is generated between the inside (space S2) and the outside of the space forming member 8, and this time, the inside of the trough 3 (the inside of the trough 3 (space S2) The sand accumulated around the intermediate discharge port 7 in the space S1) is sucked into the space S2 again from the suction port 81. Further, the sucked sand moves in the space S2 of the space forming member 8 toward the upstream 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 upstream discharge port 7. To reach. Since the momentum of the water from the intermediate discharge port 7 decreases around the upstream discharge port 7, the sand that has reached the vicinity of the upstream discharge port 7 descends from the suction port 81 toward the bottom 31 of the trough 3 and once. , Return to the space S1 of the trough 3. That is, sand is deposited around the upstream discharge port 7 in the trough 3 (space S1).

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 upstream 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 upstream discharge port 7 in the trough 3 (space S1) is sucked into the space S2 from the suction port 81, and the sucked sand is a space toward the sand collection pit 4. It moves in S2 and eventually reaches 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 upstream discharge port 7 is stopped, and 1500 liters of water per minute is discharged from only the downstream 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 8, a pressure difference is generated between the inside (space S2) and the outside of the space forming member 8 and the inside of the trough 3 (the inside of the trough 3 (space S2). The sand accumulated around the downstream discharge port 7 of the space S1) is sucked into the space S2 from the suction port 81. Further, the sucked sand moves in the space S2 of the space forming member 8 toward the intermediate discharge port 7 by the flow of water discharged from the downstream discharge port 7, and reaches the periphery of the intermediate discharge port 7. Since the momentum of water from the downstream discharge port 7 decreases around the intermediate discharge port 7, the sand that has reached the vicinity of the intermediate discharge port 7 descends from the suction port 81 toward the bottom 31 of the trough 3 and troughs. Sand accumulates around the intermediate discharge port 7 in 3 (space S1).

Subsequently, the discharge of water from the downstream 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 trough 3 (space S1) is sucked into the space S2 from the suction port 81, and the sucked sand is directed toward the upstream discharge port 7 in the space S2. It moves inside, and eventually sand accumulates around the upstream discharge port 7 in the trough 3 (space S1).

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 upstream 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 upstream discharge port 7 in the trough 3 (space S1) is sucked into the space S2 from the suction port 81, and the sucked sand is a space toward the sand collection pit 4. It moves in S2 and eventually reaches 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 upstream discharge port 7 is completed, and the removal of sand corresponding to an example of the discharge process is continuously performed.

The sand contained in the received water is transferred to the space S2 of the space forming member 8 in six stages, and then collected in the sand collecting pit 4. 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 when the sedimented sand 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 sprinkling of 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 collection point (sand collection pit 4 in the present embodiment) is provided on the downstream side in the sand transfer direction (corresponding to the upstream side of the sand basin 1 in the present embodiment), and the upstream side in the sand transfer direction. A sewage discharge point (pump well 5 in this embodiment) is provided (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, the components having the same names as the components described so far may be described with the reference numerals used so far, and duplicate description may be omitted.

FIG. 6 is a cross-sectional view of the sand basin of the second embodiment cut at the center in the width direction. Also in FIG. 6, 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. 6 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. 6 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. Both the upstream trough 3'and the downstream trough 3'are shorter troughs than the trough 3 shown in FIG. 1 and the like, and these troughs 3'and 3'are not provided with the support plate member 91. The space forming member 8 (not shown) is arranged in the trough 3 by supporting the upstream end by the upstream end face wall 36 and the downstream end by the concrete forming the sand collecting pit 4.

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.

FIG. 7 is a DD cross-sectional view of the sand basin shown in FIG. In FIG. 7, the left-right direction of the figure is the trough width direction.

The sand basin 1 of the second embodiment is a pond in which the bottom portion 1a of a pond having a rectangular cross section is repaired to form an inclined surface 6, an upstream trough 3 ′, and a downstream trough 3 ″, respectively. In FIG. 7, the portion of the bottom of the pond 1a that has been repaired with concrete is shown by cross-hatching.

As shown in FIG. 7, two downstream troughs 3 ″ are arranged in the width direction, and two upstream troughs 3 ″ are also arranged in the width direction. Therefore, in the sand basin 1 of the second embodiment, a total of four troughs are provided. By arranging the troughs side by side in the width direction, the amount of filling the pond bottom 1a with concrete is reduced when the pond bottom 1a is repaired, and it is possible to suppress a decrease in the sewage receiving capacity of the sand basin 1. A space forming member 8 is provided in each trough.

Subsequently, a modified example of the sand basin 1 described so far will be described.

FIG. 8 is a perspective view showing a modified example of the space forming member. FIG. 8 is a diagram showing a state when the space forming member 8 is viewed obliquely from the sand collecting pit 4 side. Note that FIG. 8 shows the same members as the support plate member 91, the water supply pipe 71, the wrapping prevention plate 95, and the discharge port 7 shown in FIG.

The space forming member 8 shown in FIG. 8 is a cylindrical pipe member. The space forming member 8 is arranged on a flat pond bottom portion 1a in which the trough 3 is not provided, and the lower end 83 of the space forming member 8 is in contact with the pond bottom portion 1a. A plurality of suction ports 81 are arranged side by side in the extending direction of the space forming member 8 on both sides of the space forming member 8 in the width direction. Each suction port 81 is formed by vertically cutting out the peripheral surface of a cylindrical pipe, and is provided at an intermediate portion in the vertical direction of the space forming member 8. Each suction port 81 is separated from the pond bottom portion 1a.

The suction port 81 may have a single slit shape connected in the extending direction on one side in the width direction of the space forming member 8. Further, the space forming member 8 is not limited to a tubular one or an arc-shaped one, and if the upper end portion is closed, the cross-sectional shape is U-shaped, V-shaped, or U-shaped. And so on.

Further, although the discharge port 7 of the first embodiment has a flat elongated hole shape, the shape is not limited to this shape. Further, the arrangement position of the discharge port 7 is not limited to the position shown in FIG. 3A.

FIG. 9 is a diagram showing a modified example of the discharge port. In FIG. 9, the left-right direction of the figure is the width direction of the trough 3.

Each of the discharge ports 7 shown in FIG. 9 has a perfect circular shape. The discharge port 7 shown in FIG. 6A is provided at a position corresponding to the center 8c in the radial direction of the space forming member 8. The discharge port 7 shown in FIG. 6B is provided on the inner peripheral wall of the upper end portion 82 of the space forming member 8. Therefore, it is provided above the radial center of the space forming member 8. The discharge port 7 shown in FIGS. (B) and (c) projects horizontally toward the downstream side. The discharge port 7 shown in FIG. 6C is provided at the lower end of the inner peripheral wall on the side surface 80 of the space forming member 8. That is, they are arranged on both sides of the suction port 81. The water supply pipe (not shown) connected to the discharge port 7 shown in FIGS. (B) and (c) is fixed to the inner peripheral wall on the side surface 80 of the space forming member 8 and extends along the inner peripheral wall thereof. The discharge port 7 shown in FIG. 6C also protrudes toward the downstream side, but the discharge port 7 is installed slightly upward and slightly facing the center side.

As shown in FIG. 3A and FIG. 9, the discharge port 7 does not necessarily have to be installed in the space 2 of the space forming member 8, and is more than the space forming member 8 (suction port 81). Anything may be used as long as it is installed downward and diagonally upward and can discharge the fluid into the space 2 of the space forming member 8.

FIG. 10 is a diagram showing a modified example of how to support the space forming member. In FIG. 10A, the left-right direction of the figure is the width direction of the trough 3 as in FIG. 3A. Further, in FIG. 10 (b), similarly to FIG. 3 (b), 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. It will be on the side (pump well 5 side).

In the space forming member 8 shown in FIG. 3A, the upper end portion 82 was supported by the support plate member 91, but the space forming member 8 shown in FIG. 10A has a suction port 81 (FIG. 3B). The lower ends 83 on both sides of (see) are supported by the support base 92. The support base 92 is made of concrete provided on the bottom 31 of the trough 3. The support base 92 is formed at a position on the extending trough 3 where the support plate member 91 is provided. As shown in FIG. (B), the support base 92 has an upstream inclined surface 921 and a downstream inclined surface 922, and has a support portion 923 between the upstream inclined surface 921 and the downstream inclined surface 922. The lower end 83 of the space forming member 8 is supported by the support portion 923. As shown in FIG. 9A, a horizontal plane 9231 is provided at the center of the support portion 923 in the width direction, and both sides of the horizontal plane 9231 are inclined downward toward the trough 3. Further, as shown in FIG. 3B, the water supply pipe 71 extends upward from below the support portion 923, and the water supply pipe 71 penetrates the horizontal plane 9231 and at the same time bends to the upstream side so as to be placed on the horizontal plane 9231. A discharge port 7 facing the upstream side is formed therein. As shown in FIG. 6A, the discharge port 7 also has a flat elongated hole shape.

The shape and size of the space forming member 8 shown in FIG. 10A are the same as the shape and size of the space forming member 8 shown in FIG. 3A, and have a cross-sectional shape of a 3/4 arc. is there. The radial center 8c of the space forming member 8 whose lower end 83 is supported by the support base 92 coincides with the radial center 3c of the trough 3.

Further, in the modified example shown in FIG. 10, the discharge port 7 is located below the radial center 3c of the trough 3. Further, the upper end portion 82 of the space forming member 8 is below the opening 3a of the trough 3.

The upper end portion 82 of the space forming member 8 may be located above the opening 3a of the trough 3, but the sand deposited in the space S1 in the trough 3 is efficiently accumulated in the space S2 of the space forming member 8. In order to suck well, the suction port 81 needs to be located below the opening 3a of the trough 3.

Further, as shown in FIG. 8, the space forming member 8 may be movably installed in the pond width direction with the pond bottom 1a as a flat surface without providing the trough 3 on the pond bottom 1a. By doing so, every time the space forming member 8 is slid in the pond width direction, water is discharged from the discharge port 7, and sand can be transferred to the downstream side over a wide width direction region.

Next, a settling basin provided with a transfer system will be described. The sedimentation basin is located on the downstream side of the sand basin in the sewage treatment system, receives the sewage from which the sand has been removed by the sand basin, sediments the sludge contained in the received sewage, and then puts the sedimented sludge into the sludge pit. It is moved to and removed from the sewage.

FIG. 11 is a plan view of the settling basin provided with the transfer system as viewed from above, and FIG. 12 is a side sectional view of the settling basin shown in FIG.

As shown in FIG. 11, the settling basin 10 is a rectangular pond in a plan view provided with a sludge pit 14. Hereinafter, the long side direction of the settling basin 10 may be referred to as a longitudinal direction, and the short side direction may be referred to as a width direction. The settling basin 10 shown in FIGS. 11 and 12 receives sewage from the headrace 10b provided on the right side of the figure (see FIG. 12), and the received water faces the left side of the figure, for example, 0.03 m / min. It flows slowly at a flow velocity of about 0.5 m / min (see the straight arrows shown in FIGS. 11 and 12). That is, the longitudinal direction of the settling basin is the direction of water flow, and in FIGS. 11 and 12, the right side of the figure is the upstream side and the left side is the downstream side. The water that has flowed to the downstream side of the settling basin 10 is discharged from an overflow weir (not shown) and sent to, for example, a reaction tank of a sewage treatment system. The bottom surface 100a of the bottom portion 10a is slightly inclined so that the water depth of the sedimentation basin 10 increases toward the upstream side.

A sludge pit 14 is provided on the downstream side of the headrace 10b to collect sludge accumulated on the bottom of the pond 10a. A sludge pump (not shown) is provided outside the sludge pit 14, and a suction pipe (not shown) of the sludge pump is arranged in the sludge pit 14. The sludge collected in the sludge pit 14 is sucked from the suction pipe by driving the sludge pump and transported to the outside of the settling basin 10.

The pond bottom portion 10a has a length of about 7 m in the longitudinal direction, and the pond bottom portion 10a is provided with a plurality of flow paths extending along the longitudinal direction. The flow path will be described with reference to FIG.

FIG. 13 is a cross-sectional view taken along the line EE in FIG. In FIG. 13, the left-right direction in the figure is the width direction of the sedimentation basin 10.

As shown in FIG. 13, a plurality of flow path forming members 13 are arranged on the bottom surface 100a of the pond bottom portion 10a at predetermined intervals in the width direction. These flow path forming members 13 have a pair of inclined pieces 13a connected at a substantially right angle, and have an angle shape in which a corner portion 13b is formed at a connecting portion of the inclined pieces 13a. The flow path forming member 13 has a posture in which the corners 13b face upward, and the tip portions of the inclined pieces 13a are fixed to the bottom surface 100a. As shown in FIGS. 12 and 13, these flow path forming members 13 extend in the entire longitudinal direction of the pond bottom portion 10a. Further, as shown in FIG. 13, an inclined portion 100c inclined inward in the width direction is formed at the lower end portion of the pair of side walls 10c in the settling basin 10.

In the settling basin 10 of the present embodiment, five flow paths F are provided. Of these five flow paths F, two flow paths F provided on both sides in the width direction of the settling basin 10 are defined by an inclined portion 100c of the side wall 10c, a bottom surface 100a, and an inclined piece 13a of the flow path forming member 13. In addition, the upper part is an open space. Further, the three flow paths F on the central side in the width direction are spaces defined by the inclined pieces 13a of the adjacent flow path forming members 13 and the bottom surface 100a, and are open at the upper side. The sludge in the sewage that has flowed into the settling basin 10 sinks toward the bottom 10a of the basin, enters the flow path F, and flows down along the inclined portion 100c of the side wall 10c and the inclined piece 13a of the flow path forming member 13. As a result, the settled sludge is deposited on the bottom surface 100a in the flow path F. The sludge that has settled on the corners 13b of the flow path forming member 13 also flows down to the bottom surface 100a along any of the inclined pieces 13a. Here, the inclination angle of the inclined portion 100c of the side wall 10c and the inclined piece 13a of the flow path forming member 13 is not particularly limited, but in the settling basin 10 of the present embodiment, both are set to 45 degrees. There is. Further, although the flow path forming member 13 is made of metal such as stainless steel, it may be made of concrete integrally with the bottom surface 100a. Further, the inclined piece 13a of the flow path forming member 13 and the inclined portion 100c of the side wall 10c may have an arcuate cross-sectional shape. The sludge accumulated on the bottom surface 100a in the flow path F is moved to the sludge pit 14 by the flow of water discharged from the discharge port described later.

A transfer system 20 is provided in the settling basin 10 shown in FIGS. 11 to 13. The transfer system 20 discharges the space forming member 28, the support member 29 that supports the space forming member 28, the mounting frame 26 from which the support member 29 is suspended, the water supply pipe 271, and the water supplied by the water supply pipe 271. The discharge port 27 is provided.

As shown in FIG. 13, the space forming member 28 is the center in the width direction in each flow path F, and is arranged on the bottom surface 100a in a state separated from the bottom surface 100a. Further, as shown in FIGS. 11 and 12, the space forming member 28 extends along the longitudinal direction of the settling basin 10, and the total length of the space forming member 28 is the length of the pond bottom 10a in the longitudinal direction. It is the same. The water supply pipe 271 corresponds to an example of a fluid supply pipe, one end side is connected to a water supply source (not shown), and the other end side is connected to a downstream portion of the space forming member 28 as shown in FIG. ing.

The mounting frame 26 has a U-shaped cross section, and as shown in FIGS. 11 and 13, the mounting frame 26 is bridged over a pair of side walls 10c in a state of extending in the width direction. Further, as shown in FIGS. 11 and 12, a plurality of mounting frames 26 are provided at predetermined intervals in the longitudinal direction. As shown in FIG. 13, a plurality of support members 29 are provided in a state of extending vertically at positions corresponding to the space forming members 28 in the width direction. Further, as shown in FIG. 12, a plurality of support members 29 are provided at positions corresponding to the positions of the mounting frames 26 in the longitudinal direction at predetermined intervals in the longitudinal direction. As shown in FIG. 13, these support members 29 are attached to the pipe member 291 extending in the vertical direction, the lower screw member 292 attached to the lower end of the pipe member 291 and the upper end of the pipe member 291. It has an upper screw member 293. Further, these support members 29 support the space forming member 28 by attaching the lower screw member 292 to the space forming member 28 and attaching the upper screw member 293 to the mounting frame 26.

FIG. 14A is an enlarged view showing the G portion of FIG. 13 in an enlarged manner. In FIG. 14A, the left-right direction of the figure is the width direction of the sedimentation basin 10.

The space forming member 28 shown in FIG. 14A has substantially the same cross-sectional shape as the space forming member 8 shown in FIG. 3, and the lower end of the space forming member 28 is open downward. Hereinafter, this open portion is referred to as a suction port 281. The suction port 281 is an opening having a length L of 80 mm or more in the width direction, and is separated from the bottom surface 100a. The space forming member 28 partitions the inside of the flow path F, and forms a space S3 in which a portion above the lower end is closed. The upper end portion 282 of the space forming member 28 is closed, and the arcuate side surface 280 narrows the lower end portion of the space S3 connected to the suction port 281 as it approaches the suction port 281. The upper end portion 282 of the space forming member 28 is provided with a tubular portion 283 having a thread groove corresponding to the lower screw member 292 of the support member 29 on the inner circumference. Here, the lower screw member 292 is threaded in the lower portion and not threaded in the upper portion, and the upper portion is inserted into the pipe member 291 and welded to the pipe member 291. It is fixed to. The space forming member 28 is supported by the support member 29 by screwing the lower screw member 292 into the tubular portion 283.

FIG. 14B is an enlarged view showing the H portion of FIG. 13 in an enlarged manner. Also in FIG. 14B, the left-right direction of the figure is the width direction of the sedimentation basin 10.

As shown in FIG. 14B, the upper threaded member 293 has a threaded upper portion and an unthreaded lower portion, and the lower portion is inserted into the pipe member 291. It is fixed to the pipe member 291 by welding or the like. The support member 29 is suspended from the mounting frame 26 by tightening the upper screw member 293 with nuts N from above and below the mounting frame 26 in a state of being inserted into the holes formed in the mounting frame 26. .. The position of the support member 29 can be adjusted in the vertical direction by adjusting the position of the nut N on the upper screw member 293. As a result, the vertical position of the space forming member 28 supported by the support member 29 can be adjusted, and the separation distance between the suction port 281 and the bottom surface 100a can be changed. Further, even when sewage is accumulated in the settling basin 10, the support member 29 is removed from the mounting frame 26, and the removed support member 29 is pulled up to pull up the space forming member 28 and the discharge port 27 described later. be able to. As a result, maintenance of the space forming member 28 and the discharge port 27 can be performed even when sewage is accumulated in the settling basin 10.

Further, as shown in FIG. 14A, the space S3 in the space forming member 28 is provided with a discharge port 27 for discharging a fluid in the space S3. The discharge port 27 has the same structure as the discharge port 7 shown in FIG. As described above with reference to FIG. 12, the water supply pipe 271 extending downward to the downstream portion of the space forming member 28 penetrates the space forming member 28, and as shown in FIG. 14A, the space It is in S3. The portion 2711 of the water supply pipe 271 that has entered the space S3 is downward beyond the radial center of the space forming member 28, similarly to the portion 711 of the water supply pipe 71 that has entered the space S2, as shown in FIG. It extends to the upstream side (the front side in the figure) and bends horizontally. In this embodiment, the winding prevention plate 95 shown in FIG. 3 is not provided. The reason for this is that the string-like contaminants are removed in the sand basin, and the sewage received by the sedimentation basin 10 contains almost no string-like contaminants, so it is necessary to prevent such string-like contaminants from wrapping around. This is because there is little sex.

The discharge port 27 of the present embodiment is provided at the downstream end in the longitudinal direction in the space S3, is lower than the radial center of the space forming member 28, and is lower than the suction port 281. It is located above. Water is discharged from the discharge port 27 toward the upstream side in parallel with or substantially parallel to the axis of the space forming member 28. That is, water is discharged horizontally or substantially horizontally toward the upstream side, and in FIGS. 11 and 12, the right side in the drawing is the downstream side in the discharge direction, and the left side in the figure is the upstream side in the discharge direction.

When water is discharged from the discharge port 27 into the space S3 of the space forming member 28, a pressure difference is generated between the inside (space S3) of the space forming member 28 and the outside, and is deposited on the bottom surface 100a in the flow path F. The sludge is sucked into the space S3 from the suction port 281 as shown by the curved arrow shown in FIG. Further, in the space S3 of the space forming member 28, the sucked sludge moves toward the downstream side (sludge pit 14 side) in the discharge direction by the flow of water discharged from the discharge port 27. As shown in FIG. 14A, since the suction port 281 is a narrowed opening, it becomes difficult for sludge moving in the space S3 to go out from the space S3, and the sprinkling of sludge is further suppressed. ..

Since the sludge has a smaller particle size than sand and is easier to move than sand, the sludge can be sufficiently moved at a discharge flow velocity slower than the water discharge flow velocity at the discharge port 7 shown in FIG. .. Therefore, the discharge flow velocity at the discharge port 27 of the present embodiment can be, for example, about 1/3 of the water discharge flow velocity at the discharge port 7 shown in FIG. Further, the discharge amount of water discharged from the discharge port 27 can also be about 1/3 of the discharge amount of the water discharged from the discharge port 7 shown in FIG. 3, for example, the water is discharged from the discharge port 27. The amount of water discharged can be about 500 liters per minute.

According to the transfer system 20 of the present embodiment described above, it is possible to suppress the sprinkling of sludge while sufficiently moving the sludge.

Subsequently, a sludge removal method for removing the sludge accumulated on the bottom portion 10a of the settling basin 10 of the present embodiment from the settling basin 10 will be described. This sludge removal method corresponds to an example of a contaminant removal method.

FIG. 15 is a flowchart showing the flow of the sludge removal method.

The sewage that has flowed into the settling basin 10 passes through the sludge pit 14 and reaches the upstream end of the flow path F, and further flows in the extending direction of the flow path F. While the sewage flows in the extending direction of the flow path F, the sludge contained in the sewage settles in the sludge pit 14 and the pond bottom 10a. The sludge that has settled on the inclined portion 100c of the side wall or the flow path forming member 13 in the flow path F flows down toward the bottom surface 100a. In this way, sludge is deposited on the bottom surface 100a in the flow path F.

In the sludge removal method of the present embodiment, first, a sludge pump (not shown) provided in the sludge pit 14 is driven to remove the sludge in the sludge pit 14 from the sludge pit 14 (step S1). The sludge accumulated in the sludge pit 14 at this stage is mainly the sludge that has settled in the sludge pit 14 and accumulated in the sludge pit 14 among the sludge in the sewage that has flowed into the settling basin 10.

Next, with the sludge pump driven, 500 liters of water per minute is discharged underwater for 3 minutes from the discharge port 27 (step S2). In this step S2, water is discharged from the flow path F into the space S3 partitioned by the space forming member 28. When water is discharged into the space S3 from the discharge port 27, a pressure difference is generated between the inside (space S3) of the space forming member 28 and the outside, and the sludge accumulated on the bottom surface 100a in the flow path F is sucked. It is sucked into the space S3 from the mouth 281 (see the curved arrow shown in FIG. 14A). Further, in the space S3 of the space forming member 28, the sucked sludge moves toward the downstream side (sludge pit 14 side) in the discharge direction by the flow of water discharged from the discharge port 27. The sludge that moves in the space S3 of the space forming member 28 does not easily go out of the space forming member 28 at the portion where the pressure difference is generated, and the sprinkling of sludge is suppressed. In this way, the sludge accumulated on the bottom surface 100a in the flow path F moves in the space S3 of the space forming member 28 and eventually reaches the sludge pit 14. The movement of sludge here corresponds to an example of the movement process. This moving step does not need to be performed after the water in the settling basin 10 is drained and the water in the settling basin 10 is reduced or completely eliminated, and is carried out in a state where sewage is continuously received in the settling basin. The sludge that has reached the sludge pit 14 is transported to the outside of the settling basin 10 by the sludge pump that started driving in step S1 above, and the sludge is removed from the settling basin 10. The removal of sludge here corresponds to an example of a discharge process.

Then, when the discharge of water from the discharge port 27 is completed and a predetermined time elapses thereafter, the sludge pump started to be driven in step S1 is stopped (step S3). Further, when a predetermined time elapses, or when sludge is accumulated to some extent in the sludge pit 14 due to the sludge that has settled down, step S1 is performed again. As described above, steps S1 to S3 are repeated after starting the acceptance of sewage.

According to the sludge removal method of the present embodiment, the sludge can be sufficiently moved in the settling basin 10 while suppressing the sprinkling of the sludge, and the sludge can be removed from the settling basin.

Next, a settling basin provided with the second embodiment of the transfer system will be described. In the following description, the components having the same names as the components described so far may be described with the reference numerals used so far, and duplicate description may be omitted.

FIG. 16 is a cross-sectional view showing a mode corresponding to FIG. 13 in the settling basin provided with the transfer system of the second embodiment. In FIG. 16, the left-right direction of the figure is the width direction of the sedimentation basin 10.

The transfer system 20 provided in the settling basin 10 shown in FIG. 16 includes a space forming member 28 which is a part of the trough 33, a discharge port 27 provided in the space forming member 28, and a water supply pipe 271. There is. The troughs 33 are downstream of the sludge pit 14 shown in FIG. 11 and extend in the longitudinal direction of the pond bottom portion 10a, and a plurality of troughs 33 are provided at predetermined intervals in the width direction. The trough 33 has a groove forming body 331 forming a groove, a space forming member 28, and a discharge port 27. A water supply pipe 271 extending vertically from the outside of the settling basin 10 toward the bottom 10a of the pond is connected to the discharge port 27. Further, on the bottom portion 10a of the pond, an inclined surface 16 is formed of concrete so as to be inclined downward toward the trough 33 from both sides in the width direction of the trough 33 and connected to the trough 33. The inclined surface 16 extends in the longitudinal direction of the pond bottom portion 10a. In FIG. 16, a portion of the pond bottom portion 10a formed of concrete is shown by cross-hatching.

FIG. 17A is an enlarged view showing part I of FIG. 16 in an enlarged manner. In FIG. 17A, the left-right direction of the figure is the width direction.

As shown in FIG. 17A, the trough 33 has a first arc-shaped member 33a and a second arc-shaped member 33b, each having a cross-sectional shape of a 5/8 arc. The first arc-shaped member 33a and the second arc-shaped member 33b are formed by cutting out a part of a pipe material such as stainless steel. The first arc-shaped member 33a 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). Further, the second arc-shaped member 33b is a portion (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 33 is formed by abutting and joining the end portion of the first arc-shaped member 33a corresponding to 9 o'clock to the end corresponding to 9 o'clock of the second arc-shaped member 33b. The space forming member 28 and the groove forming body 331 are formed by the first arc-shaped member 33a and the second arc-shaped member 33b. The space forming member 28 opens downward. The portion that opens downward becomes the suction port 281 of the space forming member 28. The suction port 281 is an opening having a length L of 80 mm or more in the width direction, and is separated from the bottom 331a of the groove forming body 331. The bottom 331a of the groove forming body 331 corresponds to an example of the bottom. The upper end portion 282 of the space forming member 28 is closed in an arc shape and is inclined downward. The space forming member 28 forms a space S3 in which a portion above the lower end is closed. In this space S3, the lower end portion connected to the suction port 281 becomes narrower as it approaches the suction port 281.

Further, the groove forming body 331 is open upward. Hereinafter, the left half of the groove forming body 331 in the width direction shown in FIG. 17A is referred to as one end side of the groove forming body 331, and the right half of the groove forming body 331 in the width direction is the other of the groove forming body 331. Called the end side. The space forming member 28 is connected to one end side of the groove forming body 331 via a common portion in a state of being separated from the other end side of the groove forming body 331. As a result, the other end side of the groove forming body 331 and the space forming member 28 are opened upward. Hereinafter, the portion that opens upward is referred to as an opening 334 of the trough 33. Further, the space in the groove forming body 331 excluding the space S3 of the space forming member 28 is referred to as a space S4. That is, the space in which the space S3 and the space S4 are combined corresponds to the groove, and the opening 334 of the trough 33 corresponds to the opening of the groove. The space forming member 28 in the present embodiment is provided in the groove, and the suction port 281 is located below the opening of the groove.

As described above, since the space forming member 28 is connected to one end side in a state of being separated from the other end side of the groove forming body 331, the member supporting the space forming member 28 can be omitted. As a result, the sludge settling in the groove is not hindered by the member supporting the space forming member 28 over the entire length of the trough 3.

Further, as described above, the trough 3 of the present embodiment is formed by joining a first arc-shaped member 33a having a diameter of about 250 mm and a second arc-shaped member 33b having a diameter of about 150 mm. Therefore, the gap W between the space forming member 28 and the other end side of the groove forming body 331 is secured to be about 100 mm over the entire length of the trough 33. Further, since the space forming member 28 and the groove forming body 331 have a common portion having a part common to each other, it is easy to secure a gap W, and as a result, the size of the trough 33 in the width direction is suppressed. Can be done.

The sludge contained in the sewage that has flowed into the settling basin 10 is settled to the bottom 10a of the pond in the process of the sewage flowing downstream, and the sludge that has settled on the inclined surface 16 is further along the inclined surface 16. It flows down toward the trough 33. The sludge that has flowed down from the inclined surface 16 on the right side of FIG. 17A enters the groove through the opening 3334 of the trough 33. Further, the sludge that has flowed down from the inclined surface 16 on the left side of FIG. 17A passes through the arcuate side surface of the space forming member 28 and enters the groove through the opening 334 of the trough 33. As a result, the sludge that has settled in the bottom of the pond 10a is collected in the bottom of the ditch.

FIG. 17B is a cross-sectional view taken along the line JJ in FIG. 17A. In FIG. 17B, the left-right direction of the figure is the extending direction of the trough 33, the right side of the figure is the upstream side (sludge pit 14 side), and the left side is the downstream side.

As shown in FIGS. 17A and 17B, the water supply pipe 271 extending downward to the space forming member 28 has a lower end portion penetrating the upper end portion 282 of the space forming member 28 and the space forming member 28. It communicates with the space S3 of. Further, in the space S3 of the space forming member 28, a discharge port 27 for discharging a fluid is provided in the area where the water supply pipe 271 communicates. The discharge port 27 is formed by partitioning the upper portion of the space S3 in the space forming member 28 with a partition member 272. The partition member 272 has a horizontal portion 2721 extending in a horizontal state in the extending direction of the trough 33, and an inclined portion 2722 inclined upward from the downstream end portion of the horizontal portion 2721. The horizontal portion 2721 is connected to both sides in the width direction sandwiching the upper end portion on the inner peripheral surface of the space forming member 28, and the end portion on the upstream side (sludge pit 14 side) thereof is upstream from the lower end portion of the water supply pipe 271. Located on the side. Further, the inclined portion 2722 has an end portion on the downstream side connected to the downstream side of the inner peripheral surface of the space forming member 28 with respect to the portion to which the lower end portion of the water supply pipe 271 is connected, and connects the downstream side of the discharge port 27. It is blocked. As a result, the region in which the water supply pipe 271 communicates in the space S3 of the space forming member 28 is partitioned by the partition member 272. The discharge port 27 of the present embodiment may have the same structure as the discharge port 27 shown in FIG.

From the discharge port 27, the water supplied from the water supply pipe 271 is discharged horizontally or substantially horizontally toward the upstream side (see the arrow pointing to the right in FIG. 17B). That is, in FIG. 17B, 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. When water is discharged from the discharge port 27 into the space S3 of the space forming member 28, a pressure difference is generated between the inside (space S3) and the outside (space S4) of the space forming member 28, and the water is deposited on the bottom of the groove. The sludge is sucked into the space S3 from the suction port 281 as shown by the curved arrow shown in FIG. 17A. Further, in the space S3 of the space forming member 28, the sucked sludge moves toward the downstream side (sludge pit 14 side) in the discharge direction by the flow of water discharged from the discharge port 27. As shown in FIG. 17A, since the suction port 281 is an opening narrowed in the width direction, it becomes difficult for sand moving in the space S2 to come out from the space S3, and sludge is sprinkled up. Is suppressed more.

That is, the settling basin provided with the transfer system of the second embodiment is a settling basin in which sludge 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 sludge accumulated in the groove into the space by discharging a fluid from the discharge port.
The space forming member functions as a path for sludge 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 bottom 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 provided along the extending direction of the groove.

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

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

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

Further, the pond bottom portion 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.

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

Next, a settling basin provided with the third embodiment of the transfer system will be described.

FIG. 18 is a plan view of the settling basin provided with the third embodiment of the transfer system as viewed from above. In FIG. 18, the left-right direction in the figure is the longitudinal direction of the settling basin 10, and the vertical direction in the figure is the width direction of the settling basin 10. FIG. 19 is a KK cross-sectional view of the settling basin shown in FIG. 18, and in FIG. 19, the left-right direction of the figure is the longitudinal direction of the settling basin 10. Further, FIG. 20 is a cross-sectional view taken along the line LL of the settling basin shown in FIG. 18, and in FIG. 20, the left-right direction of the figure is the width direction of the settling basin 10.

In the settling basin 10 shown in FIGS. 18 to 20, the longitudinal direction is the direction of water flow, and in FIGS. 18 and 19, the right side of the figure is the upstream side and the left side is the downstream side. The settling basin 10 has a pair of side walls 10c extending in the longitudinal direction (see FIG. 18), an upstream wall 10h extending in the width direction and located on the upstream side, and an upstream wall extending in the width direction and located on the downstream side. It is a rectangular pond in a plan view having a downstream wall of 10 g, a length of about 35 m in the longitudinal direction, and a length of about 25 m in the width direction. As shown in FIG. 19, 100 g of an overflow weir is provided on the downstream wall 10 g. The sewage that has passed over 100 g of the weir is sent to, for example, a reaction tank of a sewage treatment system. Further, as shown in FIG. 18, the upstream wall 10h is provided with an opening 100h communicating with a headrace (not shown). Each of the pair of side walls 10c and the upstream wall 10h is provided with a plurality of pillars at predetermined intervals in the direction in which they extend.

As shown in FIGS. 18 and 20, a sludge pit 14 is provided at the central portion in the width direction on the upstream side of the settling basin 10. A sludge pump (not shown) is provided outside the sludge pit 14, and a suction pipe (not shown) of the sludge pump is arranged in the sludge pit 14. Further, as shown in FIGS. 18 and 20, a pair of accumulation grooves 141 extending in the width direction and connected to the sludge pit 14 are provided on both sides of the sludge pit 14 in the width direction. Each of these accumulation grooves 141 is a groove having a length of about 4 m in the longitudinal direction of the settling basin 10 which is its own width and a length of about 10 m in the width direction of the settling basin 10 which is its own total length. .. These accumulation grooves 141 correspond to an example of the transfer path, and the groove bottom surface 141a of the accumulation groove 141 corresponds to an example of the groove bottom portion of the transfer path. As shown in FIG. 20, the bottom surface 141a of each of the accumulation grooves 141 is inclined so that the water depth of the sedimentation basin 10 increases toward the sludge pit 14.

As shown in FIG. 18, the upstream side of the sludge pit 14 and the accumulation groove 141 in the settling basin 10 is divided into four regions by three partition walls 10d extending in the longitudinal direction, and each region is divided into four regions. A pond bottom 10a is provided. Similar to the side wall 10c, the partition wall 10d is also provided with pillar portions at predetermined intervals in the longitudinal direction, and the lower end portion of the partition wall 10d where the pillar portion is not provided is shaped like a haunch. The cross-sectional shape is large. Further, a beam 10e (see FIG. 19) extending in the width direction is provided between the columns of the adjacent partition walls 10d. Further, a beam extending in the width direction is also provided between the pillar portion of the side wall 10c and the pillar portion of the partition wall 10d. In FIGS. 18 and 20, the beams are omitted for simplification of the drawings. Further, as shown in FIGS. 19 and 20, a ceiling 10f is provided above the sludge pit 14 and the accumulation groove 14 at the upstream side of the pond bottom portion 10a. In FIG. 18, since the accumulation groove 14 is shown, the ceiling 10f is omitted.

On the bottom surface 100a of each of the pond bottoms 10a shown in FIG. 19, the flow path forming members 13 having the same cross-sectional shape as the flow path forming members 13 shown in FIGS. 11 to 13 are substantially longitudinal of the bottom surface 100a of the pond bottom 10a. It is arranged in a state of extending over the entire length. The lower end portion of the side wall 10c of the present embodiment is not provided with the inclined portion 100c shown in FIG. 13, and the lower end portion of the partition wall 10d is also not provided with the inclined portion. In the present embodiment, the second flow path forming member 131 made of one inclined piece is arranged on both end sides in the width direction of the bottom surface 100a of the pond bottom portion 10a. In the present embodiment, the flow path forming member 13 and the second flow path forming member 131 represent 4 in each of the four regions of the pond bottom 10a partitioned by the partition wall 10d, as shown in FIG. The two flow paths F are formed in a state of being arranged in the width direction. The second flow path forming member 131 may be omitted by providing an inclined portion at the lower end portion of the side wall 10c or the partition wall 10d.

A transfer system 20 is provided in each region of the settling basin 10 partitioned by the partition wall 10d. Similar to the transfer system 20 shown in FIGS. 11 to 14, the transfer system 20 includes a space forming member 28, a support member 29, a mounting frame 26, a water supply pipe 271, and a discharge port 27. The space forming member 28 has the same cross-sectional shape as the space forming member 28 shown in FIG. 14, and is arranged in each of the flow paths F in a state of extending over substantially the entire length in the longitudinal direction of the flow path F. These space forming members 28 are supported by the support member 29 and the mounting frame 26 having the same configuration as the support member 29 and the mounting frame 26 shown in FIGS. 11 to 13 in a state of being separated from the bottom surface 100a of the pond bottom portion 10a. There is. The mounting frame 26 extends in the width direction of the settling basin 10 in each region of the settling basin 10 partitioned by the partition wall 10d, and the mounting frame 26 is spaced in the longitudinal direction of the settling basin 10. Multiple are placed apart. Both ends of the mounting frame 26 are supported by the receiving frame 261. These receiving frames 261 are fixed to the portions above the water surface in each of the side wall 10c and the partition wall 10d. A support member 29 is suspended from a mounting frame 26 supported by each of these receiving frames 261.

As shown in FIG. 19, a plurality of water supply pipes 271 of the present embodiment are connected to the upper end portions of the space forming member 28 at intervals of about 6 m in the longitudinal direction. Similar to the water supply pipe 271 shown in FIG. 14, these water supply pipes 271 penetrate the space forming member 28 and enter the space forming member 28, and then bend to the upstream side (sludge pit 14 and accumulation groove 141 side). The same discharge port as the discharge port 27 shown in 14 is formed. As a result, in the present embodiment, five discharge ports are provided in each space forming member 28 at intervals of about 6 m in the longitudinal direction. From these discharge ports, the water supplied from the water supply pipe 271 is discharged horizontally or substantially horizontally toward the upstream side (right side in FIGS. 18 and 19). That is, in FIGS. 18 and 19, 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. Hereinafter, among the five discharge ports formed in each of the space forming members 28, the discharge port on the most downstream side in the discharge direction (the most upstream side in the settling basin 10) may be referred to as a first discharge port. It may be referred to as a second discharge port, a third discharge port, a fourth discharge port, and a fifth discharge port, respectively, in the order in which they are provided from the first discharge port toward the upstream side in the discharge direction (downstream side in the settling basin 10). is there. Seen from the settling basin 10 shown in FIGS. 18 and 19, the first discharge port is provided on the most upstream side of the water flow in the settling basin 10, and the fifth discharge port is the water in the settling basin 10. It will be the one provided on the most downstream side of the flow. In addition, in FIG. 18 and FIG. 20, the water supply pipe 271 is omitted for the sake of simplification of the drawings.

As shown in FIGS. 18 and 19, the flow path forming member 13 and the second flow path forming member 131'extending in the width direction of the settling basin 10 settle on the groove bottom surface 141a of each of the pair of accumulation grooves 141. A plurality of flow paths F'are arranged at intervals in the longitudinal direction of the pond 10 and extend over substantially the entire length of the accumulation groove 141 to form a flow path F'. In the present embodiment, three flow paths F'are formed in each of the pair of accumulation grooves 141 sandwiching the sludge pit 14. A second transfer system 20'is provided in each of the pair of accumulation grooves 141. Like the transfer system 20, the second transfer system 20'includes a space forming member 28, a support member 29, a mounting frame 26, a water supply pipe 271, and a discharge port. The space forming member 28 has the same cross-sectional shape as the space forming member 28 shown in FIG. 14, and is arranged in each of the flow paths F'in a state of extending over substantially the entire length of the flow path F'. These space forming members 28 are separated from the groove bottom surface 141a of the accumulation groove 141 by a support member 29 having the same configuration as the support member 29 of the transfer system 20 and a mounting frame 26 having the same cross-sectional shape as the mounting frame 26 of the transfer system 20. It is supported in the state. As shown in FIG. 18, the mounting frame 26 is arranged above the accumulation groove 141 in a state extending in the longitudinal direction of the settling basin 10 at a predetermined interval in the width direction of the settling basin 10. In the present embodiment, three mounting frames 26 are arranged in each of the accumulation grooves 141. As shown in FIGS. 18 and 20, of the three mounting frames 26, the mounting frame 26 arranged at the center in the width direction of the settling basin 10 has a receiver whose upstream end portion is fixed to the upstream wall 10h. It is supported by the frame 261 and the downstream end portion is supported by the receiving frame 261 fixed to the upstream surface of the partition wall 10d. Further, as shown in FIGS. 18 and 19, of the three mounting frames 26, each of the two mounting frames 26 arranged on the outer side in the width direction of the settling basin 10 has an upstream end portion of the settling basin 10. It is supported by a receiving frame 261 fixed to the upstream wall 10h of the above, and a downstream end portion is supported on a mounting frame 26 arranged on the most upstream side in the transfer system 20. A support member 29 is suspended from each of these mounting frames 26.

As shown in FIG. 20, in each of the space forming members 28 of the second transfer system 20', the water supply pipe 271 has an outer end portion in the width direction of the settling basin 10 and an intermediate portion in the width direction of the settling basin 10. It is connected to the. Similar to the water supply pipe 271 shown in FIG. 14, these water supply pipes 271 penetrate the space forming member 28 and enter the space forming member 28, and then bend toward the center side in the width direction (sludge pit 14 side). The same discharge port as the discharge port 27 shown is formed. As a result, in the present embodiment, two discharge ports are provided in each of the space forming members 28 at intervals of about 5 m in the longitudinal direction. From these discharge ports, the water supplied from the water supply pipe 271 is discharged horizontally or substantially horizontally toward the sludge pit 14 side. That is, in each of the pair of accumulation grooves 141, the outside of the settling basin 10 in the width direction is on the upstream side in the discharge direction, and the inside of the settling basin 10 in the width direction (sludge pit 14 side) is on the downstream side in the discharge direction. Hereinafter, of the two discharge ports formed in each of the space forming members 28 of the second transfer system 20', the discharge port on the upstream side in the discharge direction (outside in the width direction of the settling basin 10) may be referred to as an outer discharge port. The inner discharge port in the width direction of the settling basin 10 may be referred to as an inner discharge port. In FIGS. 18 and 19, the water supply pipe 271 of the transfer system 20'is omitted in order to simplify the drawings.

Subsequently, a second sludge removing method for removing the sludge accumulated in the settling basin 10 provided with the third embodiment of the transfer system from the settling basin 10 will be described. This second sludge removal method corresponds to an example of a contaminant removal method.

FIG. 21 is a flowchart showing the flow of the second sludge removal method.

The sewage that has flowed into the settling basin 10 crosses the sludge pit 14 and the accumulation groove 141, reaches the upstream end of the pond bottom 10a, and further flows along the extending direction of the pond bottom 10a. While the sewage flows, the sludge contained in the sewage settles in the sludge pit 14, the accumulation groove 141, and the bottom of the pond 10a. The sludge that has settled in the accumulation groove 141 flows down to the groove bottom surface 141a in the flow path F'through the flow path forming member 13 and the second flow path forming member 131'. Further, it flows down the outer peripheral surface of the space forming member 28 to the groove bottom surface 141a in the flow path F'. In this way, sludge is deposited on the groove bottom surface 141a in the flow path F'. Further, the sludge that has settled on the bottom portion 10a of the pond flows down to the bottom surface 100a in the flow path F along the flow path forming member 13 and the second flow path forming member 131. Further, it flows down to the bottom surface 100a in the flow path F along the outer peripheral surface of the space forming member 28. In this way, sludge is deposited on the bottom surface 100a in the flow path F.

In the second sludge removal method of the present embodiment, first, a sludge pump (not shown) provided on the outside of the sludge pit 14 is driven to remove the sludge in the sludge pit 14 from the sludge pit 14 (step S1). .. The sludge accumulated in the sludge pit 14 at this stage is mainly the sludge that has settled in the sludge pit 14 and accumulated in the sludge pit 14 among the sludge in the sewage that has flowed into the settling basin 10. The sludge pump is continuously driven until it is stopped in step S23, which will be described later.

Next, 500 liters of water per minute is discharged underwater for 3 minutes from only the inner discharge port of the two discharge ports in each accumulation groove 141 (step S2). In this step S2, water is discharged from the flow path F'to the space partitioned by the space forming member 28. When water is discharged from the inner discharge port, a pressure difference is generated between the inside and the outside of the space forming member 28, and the sludge accumulated on the groove bottom surface 141a of the inner portion in the width direction in the flow path F'is sucked. It is sucked from the mouth into the space partitioned by the space forming member 28. Further, in the space partitioned by the space forming member 28, the sucked sludge moves to the downstream side in the discharge direction (toward the sludge pit 14) by the flow of water discharged from the inner discharge port. The sludge that moves in the space partitioned by the space forming member 28 does not easily go out of the space forming member 28 at the portion where the pressure difference is generated, and the sprinkling of sludge is suppressed. In this way, the sludge accumulated on the groove bottom surface 141a of the inner portion in the width direction in the flow path F'moves in the space partitioned by the space forming member 28, and eventually reaches the sludge pit 14. The sludge that has reached the sludge pit 14 is transported to the outside of the settling basin 10 by a sludge pump, and the sludge is removed from the settling basin 10. The removal of sludge here corresponds to an example of a discharge process.

Next, the discharge of water from the inner discharge port is stopped, and this time, 500 liters of water per minute is discharged under water for 3 minutes only from the outer discharge port (step S3). In step S3 as well as in step S2, by discharging water into the space partitioned by the space forming member 28, a pressure difference is generated between the inside and the outside of the space forming member 28, and this time, the width in the flow path F'is wide. The sludge accumulated on the groove bottom surface 141a of the outer portion in the direction is sucked into the space partitioned by the space forming member 28 from the suction port. Further, the sucked sludge moves in the space partitioned by the space forming member 28 (toward the inner discharge port) downstream in the discharge direction by the flow of water discharged from the outer discharge port, and reaches the inner discharge port. To do. Since the momentum of water from the outer discharge port decreases around the inner discharge port, the sludge that has reached the periphery of the inner discharge port descends from the suction port of the space forming member 28 toward the groove bottom surface 141a. That is, sludge is deposited on the groove bottom surface 141a around the inner discharge port in the flow path F'.

Next, the discharge of water from the outer discharge port is stopped, and 500 liters of water per minute is discharged underwater for 3 minutes again from only the inner discharge port in the same manner as in step S2 (step S4). In step S4, the sludge accumulated on the groove bottom surface 141a around the inner discharge port in the flow path F'is sucked again into the space partitioned by the space forming member 28, and the sucked sludge is on the downstream side in the discharge direction. It moves through the space partitioned by the space forming member 28 (towards the sludge pit 14) and eventually reaches the sludge pit 14. Steps S2 to S4 correspond to an example of the moving process. The sludge that has reached the sludge pit 14 is removed from the settling basin 10 by a sludge pump. That is, sludge removal by a sludge pump, which corresponds to an example of the discharge process, is also performed here. The sludge discharged at this stage is mainly the sludge that has settled in the accumulation groove 141 and accumulated on the groove bottom surface 141a of the accumulation groove 141 among the sludge in the sewage that has flowed into the settling basin 10.

Next, of the five discharge ports in each of the space forming members 28 provided in the bottom portion 10a of the pond, only the first discharge port on the most downstream side in the discharge direction (the most upstream side in the settling basin 10) is 500 liters per minute. Water is discharged under water for 3 minutes (step S4). In this step S4, water is discharged from the flow path F into the space partitioned by the space forming member 28. When water is discharged from the first discharge port, a pressure difference is generated between the inside and the outside of the space forming member 28, and the sludge accumulated on the bottom surface 100a of the most upstream side portion in the flow path F is discharged from the suction port. It is sucked into the space partitioned by the space forming member 28. Further, in the space partitioned by the space forming member 28, the sucked sludge moves to the downstream side in the discharge direction (toward the sludge pit 14 and the accumulation groove 141) by the flow of water discharged from the first discharge port. Eventually, it reaches the sludge pit 14 and the accumulation groove 141. The sludge that has reached the sludge pit 14 is transported to the outside of the settling basin 10 by a sludge pump, and the sludge is removed from the settling basin 10. Here, too, sludge is removed by a sludge pump, which corresponds to an example of the discharge process.

Next, the discharge of water from the first discharge port is stopped, and this time, 500 liters of water per minute is poured underwater for 3 minutes from only the second discharge port located upstream of the first discharge port in the discharge direction. Discharge (step S6). In step S6 as well, as in step S5, by discharging water into the space partitioned by the space forming member 28, a pressure difference is generated between the inside and the outside of the space forming member 28, and this time, the second in the flow path F. The sludge accumulated on the groove bottom surface 141a around the discharge port is sucked from the suction port into the space partitioned by the space forming member 28. Further, the sucked sludge moves in the space partitioned by the space forming member 28 (toward the first discharge port) downstream in the discharge direction by the flow of water discharged from the second discharge port, and the first discharge Reach the exit. Since the momentum of the water from the second discharge port decreases around the first discharge port, the sludge that has reached the periphery of the first discharge port descends from the suction port of the space forming member 28 toward the bottom surface 100a. That is, sludge is deposited on the bottom surface 100a around the first discharge port in the flow path F.

Next, the discharge of water from the second discharge port is stopped, and 500 liters of water per minute is discharged again underwater for 3 minutes from only the first discharge port in the same manner as in step S5 (step S7). By this step S7, the sludge accumulated on the bottom surface 100a around the first discharge port in the flow path F is sucked into the space partitioned by the space forming member 28, and the sucked sludge is sucked to the downstream side in the discharge direction ( It moves through the space partitioned by the space forming member 28 (toward the sludge pit 14 and the accumulation groove 141), and eventually reaches the sludge pit 14 and the accumulation groove 141. The sludge that has reached the sludge pit 14 is removed from the settling basin 10 by a sludge pump. That is, sludge removal by a sludge pump, which corresponds to an example of the discharge process, is also performed here.

Next, after stopping the discharge of water from the first discharge port, discharge from the third discharge port (step S8) and discharge from the second discharge port (step S9) by the same steps as in steps S6 and S7. , And each step of discharging from the first discharging port (step S10) is carried out. By carrying out steps S8 to S10, the sludge accumulated on the bottom surface 100a around the third discharge port reaches the sludge pit 14 and the accumulation groove 141, and the sludge that reaches the sludge pit 14 is collected by the sludge pump. It is removed from the settling basin 10. That is, sludge removal by a sludge pump, which corresponds to an example of the discharge process, is also performed here.

Next, after stopping the discharge of water from the first discharge port, discharge from the fourth discharge port (step S11) and discharge from the third discharge port (step S12) by the same steps as in steps S8 to S10. ), Discharge from the second discharge port (step S13), and discharge from the first discharge port (step S14). By carrying out steps S11 to S14, the sludge accumulated on the bottom surface 100a around the fourth discharge port reaches the sludge pit 14 and the accumulation groove 141, and the sludge that reaches the sludge pit 14 is settled by the sludge pump. Removed from pond 10. That is, sludge removal by a sludge pump, which corresponds to an example of the discharge process, is also performed here.

Next, after stopping the discharge of water from the first discharge port, discharge from the fifth discharge port (step S15) and discharge from the fourth discharge port (step S16) by the same steps as in steps S11 to S14. , Discharge from the third discharge port (step S17), discharge from the second discharge port (step S18), and discharge from the first discharge port (step S19). By carrying out steps S15 to S19, the sludge accumulated on the bottom surface 100a around the fifth discharge port reaches the sludge pit 14 and the accumulation groove 141, and the sludge that reaches the sludge pit 14 is settled by the sludge pump. Removed from pond 10. That is, sludge removal by a sludge pump, which corresponds to an example of the discharge process, is also performed here.

By carrying out steps S5 to S19, the sludge that has settled in the bottom 10a of the pond is moved to the sludge pit 14 and the accumulation groove 141, and the sludge that has reached the sludge pit 14 is removed from the settling basin 10 by the sludge pump. To. These steps S5 to S19 correspond to an example of the moving step.

Next, after stopping the discharge of water from the first discharge port, the discharge from the inner discharge port (step S20), the discharge from the outer discharge port (step S21), and the inner side are the same as in steps S2 to S4. Discharge from the discharge port (step S22). By carrying out steps S20 to S22, the sludge that has settled in the pond bottom 10a and has been moved to the accumulation groove 141 by steps S5 to S19 reaches the sludge pit 14. The movement of sludge here also corresponds to an example of the movement process. Further, the sludge that has reached the sludge pit 14 is removed from the settling basin 10 by a sludge pump. That is, the removal of sand by the sludge pump, which corresponds to an example of the discharge process, is also performed here.

Then, when the discharge of water from the inner discharge port is completed and a predetermined time elapses thereafter, the sludge pump started to be driven in step S1 is stopped (step S23). Further, when a predetermined time elapses, or when sludge is accumulated to some extent in the sludge pit 14 due to the sludge that has settled down, step S1 is performed again. As described above, steps S1 to S23 are repeated after starting the acceptance of sewage.

According to the second sludge removal method, the sludge can be sufficiently moved in the settling basin 10 while suppressing the sprinkling of the sludge, and the sludge can be removed from the settling basin.

Next, a modification of the transfer system described so far will be described.

FIG. 22 is a diagram showing a modified example of how to support the space forming member. In FIG. 22, the left-right direction of the figure is the width direction as in FIG.

The space forming member 28 shown in FIG. 14 was supported by attaching the support member 29 to the tubular portion 283 of the upper end portion 282, but the space forming member 28 shown in FIG. 22 is on both sides of the suction port 281. The lower end 284 and the upper end portion 282 are supported by the support 39. The support 39 is formed by bending a plate material such as stainless steel, has a length of about several tens of mm in the longitudinal direction, and has a predetermined interval along the extending direction of the space forming member 28. There are multiple spaces. Further, the support 39 includes a U-shaped frame portion 391, a pair of lower end support portions 392 extending in the vertical direction, and a frame portion 391 and a lower end support portion 392 extending parallel to the bottom surface 100a. It has a pair of connected connecting portions 393. The frame portion 391 abuts on the upper end portion 282 of the space forming member 28 with the open portion facing downward, and supports the upper end portion 282. The lower end support portion 392 supports each of the lower ends 284 of the space forming member 28. The pair of connecting portions 393 are fixed on the base member 40 arranged on the bottom surface 100a. The space forming member 28 is supported by the support 39 in a state where the suction port 281 is separated from the bottom surface 100a.

FIG. 23 is a diagram showing a modified example in which the space forming member 28 shown in FIG. 13 is movably installed in the width direction. In FIG. 23, the left-right direction of the figure is the width direction as in FIG.

The space forming member shown in FIG. 13 was supported in a state where the position in the width direction was fixed by attaching the upper screw member 293 of the support member 29 to the attachment frame 26. A rail member 37 extending in the width direction is provided in place of the frame 26, and a roller member 294 movably engaged with the rail member 37 in the width direction is provided in place of the upper screw member 293 of the support member 29. There is. Further, in this modification, the flow path forming member 13 is omitted and the flow path F is not formed, and the pond bottom portion 10a is made into a flat surface composed of the bottom surface 100a. The roller member 294 can be moved in the width direction along the rail member 37 by a driving means (not shown), thereby forming a space supported by the support member 29 as shown by the arrow in the width direction in the drawing. The member 28 can be moved in the width direction. By doing so, each time the space forming member 28 is slid in the width direction, water is discharged from the discharge port 27, and sludge can be transferred to the sludge pit 14 side (see FIG. 11) over a wide area in the width direction. become able to.

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 transfer system 20 is provided in the settling basin 10, but the transfer system 20 is provided in a reservoir such as a dam lake, and the sediment settled at the bottom of the dam lake or the like is moved in one direction to be predetermined. It may be collected in the place of. The earth and sand collected at a predetermined place may be removed from the dam lake or the like by suctioning with a known sand drain pipe or the like. Further, when the transfer system 20 is provided in a reservoir such as a dam lake, it is preferable to move the space forming member as in the modified example shown in FIG. 23. Further, the transfer system 20 may be provided in a factory or the like, and the metal powder or the like generated in the factory or the like may be moved in one direction and collected in a predetermined place.

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

1 Settling basin 1a Pond bottom 3 Traf 3a Opening 4 Sand collection pit 6 Inclined surface 7 Discharge port 8 Space forming member 81 Suction port 82 Upper end S1, S2 Space 10 Settling basin 10a Pond bottom 14 Sludge pit 141 Accumulation groove 20 Transfer system Space forming member 27 Discharge port 29 Support member 33 Traf F Flow path S3, S4 Space

Claims (2)

A transfer system in which contaminants contained in the received liquid settle to the bottom.
A space-forming member extending along the bottom portion, forming a space in which the upper end portion is closed, and having an opening separated from the bottom portion below the upper end portion.
A discharge port for discharging a fluid into the space is provided.
The discharge port has a flat shape and is formed by partitioning the upper portion of the space with a partition member, and discharges a fluid toward the downstream side in the transfer direction of the contaminant. Transport system. The transfer system according to claim 1, wherein the discharge port discharges a fluid at a discharge pressure of 0.05 MPa or more and 0.3 MPa or less.

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