JP7120606B2 - sand pond - Google Patents

Description

The present invention relates to a settling basin in which sand contained in received water settles to the bottom of the basin.

Sewage treatment equipment receives wastewater such as sewage and rainwater, and after the sand contained in the wastewater settles in the bottom of the pond and in the grooves provided at the bottom of the pond, it accumulates in the bottom and grooves. Some have settling basins where sand is collected in a collection pit and removed from the sewage. After the sewage in the basin is discharged and the sand deposited on the bottom is exposed to the atmosphere, the sand is discharged from a plurality of outlets provided near the side wall of the basin. It is known to have sand collection means that move towards the ditch. Further, by setting the discharge angle of the fluid discharged from the discharge port provided near the side wall to a predetermined angle with respect to the bottom of the pond, the fluid reaching the bottom is divided into the direction of the side wall and the direction of the groove to flow near the side wall. A sedimentation basin has been proposed in which sand is washed away. (For example, refer to Patent Document 1, etc.).

JP 2011-245390 A

However, in the settling basin, there are cases where columns are formed near the side walls for the purpose of supporting buildings, pipes, etc. installed above the settling basin. In the part where the pillar is formed, the side wall protrudes toward the center in the width direction of the pond to constitute the base of the pillar, and in the part where the pillar is not formed, the side wall is recessed outward in the width direction of the pond. It may have a shape. In other words, there is a settling basin whose sidewalls are not straight. When the sand collecting means described in Patent Document 1 is applied to a settling basin whose sidewalls are not formed in a straight line, all the discharge ports are placed close to the sidewalls so that the fluid branched in the direction of the sidewalls can wash away the sand in the vicinity of the sidewalls. should be placed as follows. If all the ejection ports are arranged close to the side wall, the installation position of the ejection ports must be set for each ejection port.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a low-cost grit basin in which sand accumulated near the side walls can be flushed away with a fluid without remaining.

The settling basin of the present invention for solving the above objects is a settling basin in which sand contained in received water settles,
A groove provided in the pond bottom below the side wall and extending in a predetermined direction;
a bottom surface provided at the bottom of the pond and connected to the groove;
a supply pipe disposed facing the side wall and extending in the predetermined direction;
a plurality of discharge ports arranged in the supply pipe and discharging a fluid for flowing sand settled on the bottom surface from the side wall side toward the groove;
The side wall has a protruding wall portion that protrudes toward the center in the width direction of the pond and extends in the predetermined direction, and a recessed wall portion that is recessed outward in the width direction of the pond and extends in the predetermined direction,
The ejection port is arranged at a position facing the protruding wall and at a position facing the recessed wall,
The supply pipe is arranged between a discharge port arranged at a position facing the protruding wall portion and a discharge port arranged at a position facing the recessed wall portion for discharging the fluid discharged from the discharge port. It is characterized by having direction changing means capable of changing the direction.
Also, in the settling basin where the sand contained in the received water settles,
A groove provided in the pond bottom below the side wall and extending in a predetermined direction;
a bottom surface provided at the bottom of the pond and connected to the groove;
a discharge port for discharging a fluid for flowing sand settled on the bottom surface from the side wall side toward the groove;
The settling basin may be characterized in that the ejection direction of the fluid ejected from the ejection port can be changed.

Here, a plurality of ejection ports may be provided. When a plurality of ejection ports are provided, each ejection port may be configured so that the ejection direction of the fluid can be individually changed, or the ejection direction of several ejection ports can be changed collectively. good too.

According to this settling basin, by changing the discharge direction of the fluid discharged from the discharge port in accordance with the shape of the side wall, the amount of sand deposited in the vicinity of the side wall can be washed away regardless of the shape of the side wall. It is possible to allow fluid to reach and prevent sand from remaining. In addition, the fluid discharged from the discharge port may be directly jetted toward the sand accumulated near the side wall, or may be jetted toward the bottom surface at a position slightly away from the side wall, and the fluid after hitting the bottom surface may be diverted. It may be constructed such that the sand accumulated near the side wall is washed away by the

Further, in this settling basin, a supply pipe provided with the discharge port,
a mother pipe that supplies fluid to the supply pipe;
The supply pipe may be rotatable about the axial direction of the supply pipe with respect to the mother pipe.

By making the supply pipe rotatable about its axial direction, it is possible to change the direction of the fluid discharged from the discharge port with a simple configuration.

Furthermore, in this settling basin, the supply pipe may have a plurality of outlets.

When the supply pipe is provided with a plurality of discharge ports, the direction of fluid discharge from the plurality of discharge ports can be changed collectively by rotating the supply pipe. Therefore, the direction of fluid discharge can be easily adjusted. Become.

In addition, the settling basin has a supply pipe provided with the discharge port,
The discharge port may change the discharge direction of the fluid by a ball joint disposed between the supply pipe and the discharge port.

Since the discharge direction can be changed by the ball joint, the discharge direction of the fluid can be changed in various directions other than the circumferential direction of the supply pipe, so that the discharge direction can be finely adjusted for each discharge port.

Moreover, in this settling basin, the supply pipe may have a plurality of mounting portions to which the discharge ports are mounted in a circumferential direction of the supply pipe.

Since a plurality of mounting portions are provided in the circumferential direction of the supply pipe, the discharge port can be selectively mounted to any one of the plurality of mounting portions after the supply pipe is installed.

According to the present invention, it is possible to provide a low-cost grit basin in which the sand deposited in the vicinity of the side wall can be flushed away with a fluid without remaining.

1 is a schematic cross-sectional view of a sewage treatment facility including a settling basin according to one embodiment of the present invention; FIG. It is the top view which looked at the settling basin corresponded to one Embodiment of this invention from upper direction. FIG. 3 is a cross-sectional view of the settling basin shown in FIG. 2 taken along the line AA. It is an enlarged view which expands and shows the B section of FIG. (a) is a cross-sectional view for explaining a state in which one pipe provided with a lap joint is coupled to the other pipe; 1 is a cross-sectional view for explaining a state in which one tube is rotatable about its axial direction with respect to the other tube. (a) is a CC cross-sectional view of FIG. 4, and (b) is a cross-sectional view similar to (a) showing the bottom surface near the upstream end of the settling basin and the bottom surface near the sand collection pit. and (c) is a cross-sectional view similar to (a) for explaining the change of the ejection direction by the sand collecting nozzle. It is a water supply system diagram in sewage treatment equipment. It is explanatory drawing which shows the water level of a settling basin, and a water level sensor. (a) is a diagram showing a first modification of the supply pipe and the sand collection nozzle shown in FIG. 6, and (b) is a diagram showing a second modification of the supply pipe and the sand collection nozzle shown in FIG. be.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. A settling basin, which is one embodiment of the present invention, is placed in a sewage treatment facility to settle sand contained in wastewater such as sewage and rainwater, and then move the settled sand to a sand collection pit to remove it from the sewage. It is.

FIG. 1 is a schematic cross-sectional view of a sewage treatment facility including a settling basin according to one embodiment of the present invention.

As shown in FIG. 1 , the sewage treatment facility 1 has a settling basin 2 , a pump well 3 and a dam device 4 . Sewage such as sewage and rainwater flows into this sewage treatment facility 1 . The sewage treatment plant 1 receives sewage from the left side in FIG. The received sewage flows slowly toward the pump well 3 on the right side of the figure while sedimenting the sand contained in the sewage in the settling basin 2 (see the straight arrow shown in FIG. 1). Hereinafter, the upstream side of the received sewage flow is simply referred to as the upstream side, and the downstream side of the sewage flow is simply referred to as the downstream side.

A dam device 4 is arranged on the upstream side of the settling basin 2 of the sewage treatment facility 1 . The dam device 4 has an opening wall 41 , an inflow gate 42 and a gate drive device 43 . The wall surface on the downstream side of the opening wall 41 defines the upstream end of the settling basin 2 . An inlet 411 is opened at the lower end portion of the opening wall 41 . The inflow gate 42 is vertically movable along the wall surface on the upstream side of the opening wall 41 . When the inflow gate 42 is in the lower position indicated by the solid line in FIG. 1, the inflow port 411 is closed to block the inflow of sewage into the settling basin 2 upstream of the dam device 4 . Further, when the inflow gate 42 is pulled up to the upper position indicated by the two-dot chain line in FIG. The gate drive device 43 has a drive mechanism (not shown) therein, and moves the inflow gate 42 up and down according to a command from a control device that controls the dam device 4 . By this vertical movement, the inflow gate 42 is selectively arranged at either the upper position or the lower position.

The settling basin 2 is provided with a dust remover 5 arranged on the upstream side, a sand collection pit 6 arranged near the midstream, and a sand pump 61 for carrying out the sand in the sand collection pit 6 to the outside of the pond. It is A sand lifting pipe 64 is connected to the sand lifting pump 61 . The sand sucked by the sand lifting pump 61 is sent through the sand lifting pipe 64 to a settling separator (not shown) provided outside the settling basin 2 . The dust remover 5 is for removing contaminants (screen residues) mixed in the sewage that has flowed into the settling basin 2 . The configuration of the settling basin 2 will be detailed later.

A pump well 3 is formed downstream of the settling basin 2 of the sewage treatment facility 1 . Pump well 3 stores sewage from which sand has been removed by settling basin 2 . The bottom of the pump well 3 is the deepest part of the sewage treatment facility 1 . A pump well 3 is provided with a water pump 31 and a water supply pump 33 . The pump 31 moves the sewage stored in the pump well 3 to the outside of the sewage treatment facility 1 . A pump pipe 32 is connected to the pump 31 . The sewage sucked by the pump 31 is sent through this pumping pipe 32 to a sedimentation tank or the like (not shown) for the next stage of sewage treatment. The feedwater pump 33 is located closer to the bottom of the pump well than the water pump 31 described above. A water supply pipe 34 is connected to the water supply pump 33 . Sewage sucked by the water supply pump 33 is sent through the water supply pipe 34 to each nozzle and the like, which will be described later. The sewage sucked by the water supply pump 33 is referred to as fluid in the following description.

FIG. 2 is a top plan view of a settling basin corresponding to one embodiment of the present invention. In FIG. 2, the dust remover is indicated by a two-dot chain line rectangle. In addition, straight arrows indicate the flow direction of sewage.

As shown in FIG. 2, the settling basin 2 includes a dust remover 5, a sand collection pit 6, a bottom surface 7, a main trough 8, and a sand collection means 9 between the left side wall Wa and the right side wall Wb. In addition, the pond is roughly rectangular in plan view. The left side wall Wa and the right side wall Wb may be collectively referred to as a side wall W hereinafter. A support wall 10 for supporting the dust remover 5 is provided at the central portion in the width direction of the sand basin 2 on the upstream side. A sand collection pit 6, a bottom surface 7, and a main trough 8 are provided at the bottom of the settling basin 2, respectively. The sand settling basin 2 collects the sand that has settled on the bottom surface 7 by discharging low-pressure water of less than 3 kg/cm ² to the bottom surface 7 in a state where the sewage in the sand settling basin 2 is drained. It is a settling basin. Hereinafter, the long side direction of the settling basin 2 is called the longitudinal direction, and the short side direction is called the pond width direction.

A building, pipes, etc. (not shown) may be arranged above the settling basin 2 (on the near side of the paper surface in FIG. 2). In some cases, pillars 11 are formed adjacent to the settling basin 2 for the purpose of supporting the building and the like. In the settling basin 2 shown in FIG. 2, a pillar 11 is formed near the left side wall Wa. A protruding wall portion Wa1 that protrudes toward the center in the width direction of the pond is formed in the portion of the left side wall Wa that serves as the base of the pillar 11. As shown in FIG. Conversely, it can be said that a recessed wall portion Wa2 recessed outward in the width direction of the pond is formed in a portion of the left side wall Wa where the pillar 11 does not exist above the left side wall Wa. A portion connecting the projecting wall portion Wa1 and the recessed wall portion Wa2 is formed with an inclined wall portion Wa3 that is inclined with respect to the longitudinal direction and the pond width direction. Since there is no pillar in the vicinity of the right side wall Wb, the right side wall Wb is formed in a substantially linear shape in plan view.

The sand collection pit 6 is arranged at a position slightly downstream of the center in the longitudinal direction. The sand collection pit 6 is constituted by a recess formed between the left side wall Wa and the right side wall Wb of the settling basin 2 . Inside the sand collection pit 6, a sand pump 61, an agitating nozzle 62, and a sand collection nozzle 63 for the pit are arranged. The central portion of the sand collection pit 6 in the pond width direction is the deepest portion 6 a of the sand settling basin 2 . The deepest portion 6a is rectangular in plan view. The sand pump 61 is arranged in the deepest portion 6a. In the bottom of the sand collection pit 6, the portion between the side wall W and the deepest portion 6a forms an inclined surface 6b that gradually inclines toward the deepest portion 6a in the central portion in the width direction of the pond.

A total of four stirring nozzles 62 are arranged near each corner of the deepest portion 6a. This stirring nozzle 62 is for stirring the sand collected in the deepest part 6a. By discharging fluid from the discharge port 62a of the stirring nozzle 62 while the sand pump 61 is being driven, the efficiency of the sand pump 61 sucking sand collected at the deepest portion 6a can be increased. Two pit sand collecting nozzles 63 are arranged at each end in the width direction of the pond. When the water level of the settling basin 2 is lowered below a predetermined value, the fluid is discharged from the discharge port 63a of the pit sand collection nozzle 63, so that the sand deposited on the inclined surface 6b can be collected at the deepest portion 6a. can.

The bottom surface 7 is composed of a planar bottom surface 71 and a plurality of small troughs 72 . The bottom plane 71 and the small trough 72 are connected to the main trough 8 at the central portion in the width direction of the settling basin 2 . The bottom plane 71 is inclined downward by about 5 degrees from the side wall W at the outer end in the width direction toward the center in the width direction so that the end on the main trough 8 side is the deepest. Further, the bottom plane 71 is inclined downward by about 1 degree in the longitudinal direction so that the end portion on the side of the sand collection pit 6 becomes the deepest toward the sand collection pit 6 . The small trough 72 has a gutter shape with a U-shaped cross section, and extends from the vicinity of the side wall W in the width direction of the pond. A plurality of small troughs 72 are arranged at regular intervals in the longitudinal direction. In this embodiment, a total of 56 small troughs 72 are arranged, 28 each on one side and the other side of the pond across the main trough 8 . Similar to the bottom plane 71, the small trough 72 is also inclined downward by about 5 degrees from the side wall W toward the main trough 8 so that the portion connected to the main trough 8 is positioned closest to the bottom of the pond. there is

The main trough 8 extends in the longitudinal direction from the vicinity of the upstream end of the settling basin 2 , and an upstream main trough 81 connected to the sand collection pit 6 extends in the longitudinal direction from the vicinity of the downstream end of the settling basin 2 . and a downstream main trough 82 connected to the sand collection pit 6 . The upstream main trough 81 and the downstream main trough 82 are grooves formed by a trough forming body that is a stainless steel plate having a U-shaped cross section. Like the bottom plane 71, the upstream main trough 81 and the downstream main trough 82 are inclined downward by about 1 degree toward the sand collection pit 6, and the portion connected to the sand collection pit 6 is the deepest. there is

As shown in FIG. 2, the upstream main trough 81 has an upstream branch portion 811 and a downstream straight portion 812 that are branched into two, and is formed in a Y shape as a whole in plan view. ing. The branch portions 811 each extend in the longitudinal direction with the support wall 10 interposed therebetween. The straight portion 812 extends in the longitudinal direction at the center in the width direction of the pond. A downstream end of the upstream main trough 81 is connected to the deepest part 6 a of the sand collection pit 6 . An upstream trough nozzle 83 is provided at each upstream end of the two branched portions 811 . With the water level of the settling basin 2 lower than a predetermined value, fluid is discharged from the discharge ports 83a of the upstream trough nozzles 83, thereby moving the sand accumulated in the upstream main trough 81 to the sand collection pit 6. can be made

The downstream main trough 82 extends linearly in the longitudinal direction at the center in the width direction of the settling basin 2 . The upstream end of the downstream main trough 82 is connected to the deepest part 6 a of the sand collection pit 6 . A downstream trough nozzle 84 is provided at the downstream end of the downstream main trough 82 . Sand accumulated in the downstream main trough 82 is moved to the sand collection pit 6 by discharging fluid from the discharge port 84a of the downstream trough nozzle 84 in a state where the water level of the settling basin 2 is lower than a predetermined value. can be done.

As shown in FIG. 2, two dust removers 5 are provided in the upstream portion of the settling basin 2 side by side in the width direction of the basin with a support wall 10 interposed therebetween. These two dust removers 5, 5 have the same configuration. The dust remover 5 is for removing contaminants (screen residues) mixed in the sewage that has flowed into the settling basin 2 . One dust remover 5 shown on the upper side of FIG. 2 is supported by the left side wall Wa and the support wall 10, and the other dust remover 5 shown on the lower side of FIG. It is supported by support walls 10 . By arranging the two dust removers 5, 5 side by side in the pond width direction, the width of each dust remover 5 in the pond width direction can be shortened. By shortening the width of the dust remover 5 in the pond width direction, the strength of the dust remover 5 increases, and even if the amount and flow velocity of sewage flowing into the settling basin 2 increases due to heavy rain, the dust remover 5 will not be damaged. It can be suppressed.

FIG. 3 is a cross-sectional view of the settling basin shown in FIG. 2 along the line AA. In FIG. 3, the column and the sand pump are omitted from illustration. In addition, straight arrows indicate the flow direction of sewage. The water surface WL of the settling basin 2 fluctuates depending on the amount of rain and sewage that flows in, but in normal times when the amount of rain and sewage is assumed, the height direction of the settling basin 2 is as shown in FIG. It is located at a medium height of the

As shown in FIG. 3 , the dust remover 5 has an endless chain 51 , a plurality of rakes 52 attached to the endless chain 51 at intervals, and a filter screen 53 . The endless chains 51 are provided diagonally on both sides of the settling basin 2 in the width direction, and are wound around the ground-side sprocket 511 and the bottom-side sprocket 512 . The upper part of the endless chain 51 and the ground side sprocket 511 are arranged on the ground part of the settling basin 2 . When the water surface WL is in a normal state, when the ground side sprocket 511 is driven by a motor (not shown) in the rotational direction indicated by the arcuate arrow R, the endless chain 51 circulates and the rake 52 moves in and out of the water. FIG. 3 shows the water surface WL in a normal state. A filter screen 53 is arranged downstream of the endless chain 51 . The filtering screen 53 is made up of vertically extending bars arranged at predetermined intervals (for example, 25 mm to 75 mm) in the width direction of the pond, and blocks passage of contaminants larger than the predetermined interval. Contaminants blocked by the filter screen 53 are raked up by the rake 52, and the raked-up contaminants are placed on a conveying means such as a belt conveyor (not shown) on the ground side. The lower ends of the pond bottom side sprocket 512 and the filter screen 53 are arranged upstream of the bottom surface 7 and the main trough 8 . On the other hand, the upper ends of the ground side sprocket 511 and filter screen 53 are located above the bottom surface 7 and the upstream portion of the main trough 8 . That is, the upper portion of the endless chain 51 and filter screen 53 longitudinally overlaps the bottom surface 7 and the main trough 8 .

The sand collecting means 9 includes a first nozzle header 9a, a second nozzle header 9b, and a third nozzle header 9c arranged on the left wall Wa side of the settling basin 2, and a fourth nozzle header 9d arranged on the right wall Wb side. , a fifth nozzle header 9e and a sixth nozzle header 9f (see FIG. 2). FIG. 3 shows the sand collecting means 9 on the left side wall Wa side. Since the sand collecting means 9 on the right side wall Wb side has the same structure, description of the sand collecting means 9 on the right side wall Wb side will be omitted. Each of the first nozzle header 9 a , the second nozzle header 9 b , and the third nozzle header 9 c has ten sand collection nozzles 91 , supply pipes 92 , and mother pipes 93 . The supply pipe 92 is arranged facing the left side wall Wa and extends in the longitudinal direction. The main pipe 93 has a single pipe 931 extending upward from the settling basin 2 and a branch pipe 932 connected to the bottom end of the single pipe 931 . The single pipe 931 and the branch pipe 932 are fixed to the left side wall Wa by fixing metal fittings (not shown).

FIG. 4 is an enlarged view showing an enlarged portion B of FIG. 3 . In FIG. 4, straight arrows indicate the flow direction of sewage. Side walls are also shown in FIG. Also, although FIG. 4 shows one of the six nozzle headers, the other five nozzle headers have the same configuration as the nozzle header shown in FIG.

As shown in FIG. 4, the branch pipe 932 is connected to the single pipe 931 by a flange joint 933 . The branch pipe 932 is bifurcated below the portion connected to the single pipe 931 , and the branched portions extend in the longitudinal direction of the settling basin 2 . A supply pipe 92 to which a lap joint 934 is fixed is connected to the distal end portion of the branched portion. In this embodiment, with respect to one main pipe 93, an upstream supply pipe 921 arranged upstream of the branch pipe 932, a downstream supply pipe 923 arranged downstream of the branch pipe 932, Three feed pipes 92 are provided, an intermediate feed pipe 922 positioned between an upstream feed pipe 921 and a downstream feed pipe 923 . The ends of the upstream supply pipe 921 and the downstream supply pipe 923 opposite to the ends connected to the branch pipe 932 are closed with a lid 97 . Both ends of the intermediate supply pipe 922 are connected to the branch pipes 932 .

Three sand collecting nozzles 91 are fixed to each of the upstream supply pipe 921 and the downstream supply pipe 923 at regular intervals. Four sand collecting nozzles 91 are fixed to the intermediate supply pipe 922 at regular intervals. The number of sand collecting nozzles 91 arranged in each supply pipe 92 may be appropriately determined according to factors such as the length of the supply pipe 92 . A discharge port 911 is formed at the tip of each sand collecting nozzle 91 . Fluid is discharged into the atmosphere from the discharge port 911 of the sand collection nozzle 91 in a state in which the water level of the settling basin 2 is lowered below a predetermined value to expose the discharge port 911 and the sand deposited on the bottom surface 7 to the atmosphere. By doing so, sand deposited on the bottom surface 7 shown in FIGS. 2 and 3 can be collected in the main trough 8 .

The distance from the supply pipe 92 to the left side wall Wa differs between the portion of the supply pipe 92 facing the projecting wall portion Wa1 and the portion facing the recessed wall portion Wa2. That is, the supply pipe 92 includes a first region 92a extending from the left side wall Wa in the width direction of the pond with a first gap, and a second region 92a extending from the left side wall Wa in the width direction of the pond with a second gap. There is a region 92b. In addition, since the inclined wall portion Wa3 is formed in the portion connecting the projecting wall portion Wa1 and the recessed wall portion Wa2 in the settling basin 2 of the present embodiment, the supply pipe 92 has the first region and the There is a third area 92c that is an area that connects the second areas. The sand collection nozzles 91 and their discharge ports 911 are arranged facing the left side wall Wa and fixed to the supply pipe 92 in a longitudinal direction. In the second nozzle header 9b shown in FIG. 4, the upstream supply pipe 921 is arranged to face the projecting wall portion Wa1. That is, the area where the upstream supply pipe 921 is located corresponds to the first area 92a. On the other hand, a region of the intermediate supply pipe 922 where the discharge port 911 is arranged, which is located closest to the upstream supply pipe 921, is arranged so as to face the inclined wall portion Wa3. That is, that area corresponds to the third area 92c. Also, in the intermediate supply pipe 922, an area in which the three discharge ports 911 are arranged from the downstream supply pipe 923 side, and in the downstream supply pipe 923, two discharge ports 911 are arranged from the intermediate supply pipe 922 side. The arranged region is arranged so as to face the recessed wall portion Wa2. That is, those areas correspond to the second area 92b. In addition, the region of the downstream supply pipe 923 where the most downstream outlet 911 is arranged is arranged to face the inclined wall portion Wa3. That is, that area corresponds to the third area 92c. Between each of these areas is provided a means of reorientation using lap joints 934 .

FIG. 5(a) is a cross-sectional view for explaining a state in which one pipe provided with a lap joint is joined to the other pipe, and FIG. FIG. 4 is a cross-sectional view for explaining a state in which one of the provided tubes is rotatable about its axial direction with respect to the other tube; In FIG. 5, a supply pipe is shown as one pipe, and a branch pipe is shown as the other pipe.

A lap joint 934 is welded to the end of the supply pipe 92, as shown in FIGS. 5(a) and 5(b). The lap joint 934 is composed of a small diameter portion 934a welded to the supply pipe 92 and a large diameter portion 934b arranged on the branch pipe 932 side. The small diameter portion 934 a is formed to have the same outer diameter as the outer diameter of the supply pipe 92 . A free flange 935 is arranged on the outer circumference of the lap joint 934 . The free flange 935 has a ring shape with an inner diameter slightly larger than the outer diameter of the lap joint 934 . Eight through-holes 935a into which the bolts 95 are inserted are equally formed in the free flange 935 in the circumferential direction. The free flange 935 is coupled to the lap joint 934 so as to be rotatable and axially movable relative to the lap joint 934 . A fixed flange 9322 is welded to the outer diameter portion of the tip of the branch pipe 932 . Eight through-holes 9322a into which the bolts 95 are inserted are formed in the fixed flange 9322 similarly to the free flange 935 . A ring-shaped packing 94 is arranged between the lap joint 934 and the fixed flange 9322 . This packing 94 is for preventing leakage of fluid passing through the inside of the supply pipe 92 and the branch pipe 932 when the supply pipe 92 and the branch pipe 932 are joined.

The bolt 95 is inserted into the through hole 9322 a of the fixed flange 9322 and the through hole 935 a of the free flange 935 . When the bolt 95 and nut 96 are tightened, the lap joint 934 is sandwiched between the fixed flange 9322 and the free flange 935 together with the packing 94 as in the supply pipe 92 shown in FIG. A supply tube 92 is fixed relative to 932 . On the other hand, when the bolt 95 is loosened, the supply pipe 92 becomes rotatable about its axial direction with respect to the branch pipe 932, like the supply pipe 92 shown in FIG. 5(b). That is, in the present embodiment, since the mother pipe 93 (see FIG. 3) and the supply pipe 92 are connected using the lap joint 934 and the free flange 935, the supply pipe 92 can It is configured to be steplessly rotatable with respect to the main pipe 93 . Even if another loose flange such as a loose flange is used instead of the lap joint 934, the supply pipe 92 can be connected to the main pipe 93 so as to be rotatable steplessly.

4, between the ejection port 911 arranged in the first region 92a and the ejection port 911 arranged in the third region 92c, and between the ejection port 911 arranged in the second region 92b and the third region 92b. A lap joint 934 is arranged between the outlets 911 arranged in the region 92c. Therefore, the discharge ports 911 arranged in the first region 92a, the second region 92b, and the third region 92c are configured so as to rotate steplessly about the axial direction of the supply pipe 92 independently of each other. With this configuration, it is possible to set the ejection direction of the fluid in the ejection port 911 of each region according to the distance from the supply pipe 92 to the left side wall Wa. The lap joint 934 arranged between the ejection port 911 arranged in the first region 92a and the ejection port 911 arranged in the third region 92c corresponds to an example of the first direction changing means. Also, the lap joint 934 arranged between the ejection port 911 arranged in the second region 92b and the ejection port 911 arranged in the third region 92c corresponds to an example of the second direction changing means. In addition, in the first region 92a of the supply pipe 92 shown in FIG. 4, the fluid discharge direction of the three discharge ports 911 arranged in the first region 92a can be collectively changed. The discharge direction can be easily adjusted. In the second region 92b of the supply pipe 92 shown in FIG. Since the outlets 911 can be changed collectively, the ejection direction in the second region 92b can be easily adjusted. That is, the lap joint 934 configured so that the discharge directions of the plurality of discharge ports 911 can be collectively changed corresponds to an example of collective direction changing means. In addition, when the longitudinal direction of the third region 92c is short and the discharge port 911 does not exist in the third region 92c, or when the third region 92c does not exist, the overlap between the first region 92a and the second region 92b may occur. A joint 934 may be arranged.

FIG. 6(a) is a cross-sectional view taken along line CC of FIG. The side walls and bottom plane are also shown in FIG. 6(a).

As described above, the left side wall Wa has the projecting wall portion Wa1 and the recessed wall portion Wa2. In FIG. 6A, the projecting wall portion Wa1 is indicated by a solid line, and the recessed wall portion Wa2 is indicated by a two-dot chain line. In the discharge port 911 indicated by the solid line in FIG. 6A, the fluid discharge direction is directed toward the center in the width direction of the pond rather than downward from the center of the supply pipe 92 (vertical direction). At the discharge port 911, the angle θ at which the fluid is discharged with respect to the bottom plane 71 is about 50 degrees. By setting the angle θ to approximately 50 degrees, the fluid that has reached the bottom plane 71 can be split into a direction toward the main trough 8 and a direction toward the projecting wall portion Wa1. This angle θ may be any angle that allows the discharged fluid to flow in the direction toward the main trough 8 and the direction toward the protruding wall portion Wa1, and specifically, it should be 30 degrees or more and 60 degrees or less with respect to the bottom plane 71 . I wish I had. By setting this angle, when the supply pipe 92 and the left side wall Wa are close to each other like the projecting wall portion Wa1, that is, in the first region 92a, the bottom plane 71 between the supply pipe 92 and the left side wall Wa The diverted fluid also reaches the deposited sand and can wash the sand away. In addition, since the discharge direction of the fluid is directed toward the main trough 8 side in the center of the pond width direction rather than the vertical direction of the supply pipe 92, the force of the fluid flowing toward the main trough 8 side is stronger than the force of the fluid flowing toward the left side wall Wa. becomes stronger. The momentum of this fluid allows sand deposited on the bottom plane 71 between the supply pipe 92 and the main trough 8 to flow efficiently toward the main trough 8 .

On the other hand, the supply pipe 92 and the left side wall Wa are separated from each other at the concave wall portion Wa2 indicated by the two-dot chain line in FIG. 6(a). Therefore, in the discharge direction of the discharge port 911 indicated by the solid line, even if the discharged fluid is diverted, it does not reach the vicinity of the recessed wall portion Wa2, or even if it reaches, only a very small amount of the fluid reaches. If the amount of fluid reaching the vicinity of the recessed wall portion Wa2 is small, the sand deposited between the supply pipe 92 and the recessed wall portion Wa2 cannot be sufficiently washed away near the recessed wall portion Wa2.

In this embodiment, since the supply pipe 92 is configured to be rotatable about its axial direction, the discharge direction of the fluid from the sand collecting nozzle 91 can be freely changed. In FIG. 6(a), the sand collecting nozzle 91 in which the ejection direction of the fluid ejected from the ejection port 911 is adjusted corresponding to the position of the recessed wall portion Wa2 is indicated by a two-dot chain line. In the sand collecting nozzle 91 indicated by the two-dot chain line, the direction of discharge of the fluid discharged from the discharge port 911 is directed outward in the width direction of the pond from the direction directly downward from the center of the supply pipe 92 (vertical direction). there is By adjusting the discharge direction of the fluid discharged from the discharge port 911 according to the distance from the supply pipe 92 to the left side wall Wa, the supply pipe 92 and the left side wall Wa are spaced apart like the second region 92b. However, the sand deposited near the left side wall Wa can be sufficiently washed away. In the present embodiment, since the mother pipe 93 and the supply pipe 92 or the supply pipes 92 are connected to each other using the lap joint 934 and the free flange 935, the connected supply pipe 92 can be displaced around its axis. It can be rotated in stages. Since it can be rotated steplessly, the supply pipe 92 (third region 92c) facing the inclined wall portion Wa3 (see FIG. 2) between the projecting wall portion Wa1 and the recessed wall portion Wa2 can be rotated as shown in FIG. ) and the ejection direction of the sand collecting nozzle 91 indicated by the two-dot chain line.

In addition, in this embodiment, since the main pipe 93 is provided with the branch pipe 932, a total of three pipes, ie, the upstream supply pipe 921, the intermediate supply pipe 922, and the downstream supply pipe 923, are provided for one main pipe 93. are connected side by side in the longitudinal direction of the settling basin 2 . On the other hand, if there is no branch pipe 932 and the supply pipe 92 is connected to the single pipe 931, there are only two supply pipes 92 at most in the longitudinal direction of the settling basin 2 for one mother pipe 93. can not connect. That is, there are two supply pipes 92 extending from the top end of the mother pipe 93 to the upstream side of the settling basin 2 and the other supply pipe 92 extending to the downstream side. The ejection direction of the fluid ejected from the ejection port 911 can be set for each supply pipe 92 . Therefore, compared with the case where the branch pipe 932 is not provided, when the branch pipe 932 is provided, the discharge direction of the fluid discharged from the discharge port 911 can be adjusted at many points in the longitudinal direction of the settling basin 2. The shape of the side wall W makes it possible to respond flexibly.

FIG. 6(b) is a cross-sectional view similar to FIG. 6(a) showing the bottom surface near the upstream end of the settling basin and the bottom surface near the sand collection pit. Side walls and a bottom plane are also shown in FIG. 6(b).

As described above, the bottom plane 71 is inclined downward by about 1 degree toward the sand collection pit 6 so that the end on the sand collection pit 6 side is the deepest toward the sand collection pit 6 (FIG. 3). reference). Therefore, the bottom plane 71 near the sand collection pit 6 is located at a lower position than the bottom plane 71 near the upstream end of the settling basin 2 . In FIG. 6B, the bottom plane 71 near the upstream end of the settling basin 2 is indicated by solid lines, and the bottom plane 71 near the sand collection pit 6 is indicated by two-dot chain lines. As shown in the figure, even if the fluid is discharged from the discharge port 911 at the same position, the upstream end of the settling basin 2 and the vicinity of the sand collection pit 6 have a height of the bottom plane 71 . Since the positions are different, a difference in distance Y occurs at the point at which the discharged fluid reaches the bottom plane 71 . Especially in the settling basin 2 having a long length in the longitudinal direction, the distance Y becomes long, and even if the discharge direction is optimal for one of the upstream end of the settling basin 2 and the vicinity of the sand collection pit 6, it is inefficient for the other. In some cases, the direction of discharge may be changed. In this embodiment, since the direction of fluid ejection from the ejection port 911 can be changed, the fluid can be ejected in the optimum ejection direction corresponding to the depth of the bottom plane 71 (the height from the supply pipe 92 to the bottom plane 71). can be discharged.

FIG. 6(c) is a cross-sectional view similar to FIG. 6(a) for explaining the change of the ejection direction by the sand collecting nozzle. Side walls and a bottom plane are also shown in FIG. 6(c).

As shown in FIG. 6(c), the sand collection nozzle 91 is bent at the intermediate portion and formed in an inverted V shape when viewed in the longitudinal direction in the state indicated by the solid line. Since it is formed in an inverted V shape, when the sand collection nozzle 91 shown by the solid line is rotated 180 degrees around the axis L of the attachment portion to the supply pipe 92, it becomes as shown by the two-dot chain line. , the discharge direction of the fluid can be changed from the center side in the width direction of the pond to the outside in the width direction of the pond. By forming the sand collecting nozzle 91 in an inverted V shape and configuring the connecting portion between the sand collecting nozzle 91 and the supply pipe 92 to be rotatable, it is possible to change the discharge direction of the fluid for each discharge port 911. become. That is, the shape of the sand collection nozzle 91 and the configuration in which the sand collection nozzle 91 is rotatable with respect to the supply pipe 92 in this embodiment correspond to an example of individual direction changing means.

FIG. 7 is a water supply system diagram in the sewage treatment facility.

As shown in FIG. 7, the water supply pump 33 supplies the water of the pump well 3 selectively to the stirring nozzle 62, the pit sand collection nozzle 63, the upstream trough nozzle 83, the downstream trough nozzle 84, and the sand collection means 9. supply to The water supply pipe 34 connected to the water supply pump 33 has a supply switching valve Va for switching whether or not to supply the fluid to the above nozzles and the sand collection means 9 side, and a pump well for the fluid sucked up by the water supply pump. A release switching valve Vb for switching whether to return to 3 is provided. A channel between the supply switching valve Va and the stirring nozzle 62 is provided with a stirring switching valve Vc for switching whether or not the fluid is supplied to the stirring nozzle 62 . A pit sand collection switching valve Vd for switching whether or not the fluid is supplied to the pit sand collection nozzle 63 is provided in the pipeline between the supply switching valve Va and the pit sand collection nozzle 63 . A pipeline between the supply switching valve Va and the upstream trough nozzle 83 is provided with an upstream trough switching valve Ve for switching whether or not the fluid is supplied to the upstream trough nozzle 83 . A pipeline between the supply switching valve Va and the downstream trough nozzle 84 is provided with a downstream trough switching valve Vf for switching whether or not the fluid is supplied to the downstream trough nozzle 84 . Further, in each pipe line between the supply switching valve Va and each nozzle header 9a, 9b, 9c, 9d, 9e, 9f of the sand collecting means 9, each nozzle header 9a, 9b, 9c, 9d, 9e, 9f Sand collection switching valves Vg1, Vg2, Vg3, Vg4, Vg5, and Vg6 are provided for switching whether or not to supply the fluid. These switching valves are composed of electromagnetic valves, and opening and closing of the valves are controlled by a control device (not shown).

FIG. 8 is an explanatory diagram showing the water level of the settling basin and the water level sensor.

As shown in FIG. 8, a water level sensor 99 is arranged in the sand collection pit 6 of the settling basin 2 . This water level sensor 99 detects a first high water level HHWL at which the water level of the settling basin 2 is higher than the upper end 6c of the sand collection pit 6 and a lower end of the main trough 8 at which the water level is lower than the upper end 6c of the sand collection pit 6. A second high water level HWL above 8a, a low water level LWL below the sand collection pit 6, an intermediate water level MWL between the second high water level HWL and the low water level LWL, and a low water level LWL. It detects and outputs that the interlock water level LLWL has become even lower.

The operation of the sewage treatment facility 1 having the above configuration will be described. At a predetermined time when a certain amount of sand has accumulated on the bottom of the settling basin 2, the sewage treatment facility 1 removes the accumulated sand. This timing may be regular, such as once a month, or may be when the total amount of wastewater flowing into or discharged from the settling basin 2 reaches a certain amount. In the sand removal operation, the inflow gate 42 of the dam device 4 shown in FIG. Next, the water level of the settling basin 2 is lowered by driving the water pump 31 . When the water level of the pump well 3 drops to a predetermined value, the lift pump 31 is stopped. When the water level of the settling basin 2 drops to the second high water level HWL, the water supply pump 33 is driven, fluid is discharged from the stirring nozzle 62, and the sand pump 61 is driven. Thereafter, the sand pump 61 is automatically controlled to stop driving according to the output indicating the low water level LWL from the water level sensor 99 and restart driving according to the output indicating the second high water level HWL. . On the other hand, the water supply pump 33 continues to be driven until the sand removal operation is completed. The sand that has flown into the sand collection pit 6 is conveyed to a sediment separator (not shown) outside the settling basin 2 by the sand pump 61 while the sand pump 61 is being driven. When the water level sensor 99 detects that the water level has reached the first high water level HHWL or the interlock water level LLWL, it is considered that some kind of abnormality has occurred. Stop.

After that, fluid is discharged from the stirring nozzle 62 and the upstream trough nozzle 83 for a certain period of time to flow the sand accumulated in the upstream main trough 81 into the sand collecting pit 6 . After a certain period of time has passed, the discharge of the fluid from the stirring nozzle 62 and the upstream trough nozzle 83 is stopped, and the fluid is discharged from the discharge port 911 provided in the fifth nozzle header 9e for a certain period of time. By this discharge, sand accumulated on the bottom surface 7 between the right side wall Wb near the fifth nozzle header 9e and the upstream main trough 81 can be washed away to the upstream main trough 81. After a certain period of time has passed, the ejection of the fluid from the ejection port 911 provided in the fifth nozzle header 9e is stopped. Then, the fluid is discharged from the stirring nozzle 62 and the upstream trough nozzle 83 for a certain period of time, and the sand that has flowed to the upstream main trough 81 is sent to the sand collection pit 6 . After that, the discharge of the fluid from the stirring nozzle 62 and the upstream trough nozzle 83 is stopped, and the fluid is discharged from the discharge port 911 provided in the second nozzle header 9b for a certain period of time. In this embodiment, the discharge port 911 in the vicinity of the recessed wall portion Wa2 and the inclined wall portion Wa3 of the left side wall Wa has a certain amount of fluid in the left side wall Wa according to the distance from the supply pipe 92 to the left side wall Wa. The discharge direction of the fluid is adjusted so as to reach the Therefore, all the sand deposited on the bottom surface 7 between the left side wall Wa near the second nozzle header 9b and the upstream main trough 81 can be washed away to the upstream main trough 81. After a certain period of time has elapsed, the ejection of fluid from the ejection openings 911 provided in the second nozzle header 9b is stopped. Then, the fluid is discharged from the stirring nozzle 62 and the upstream trough nozzle 83 for a certain period of time, and the sand that has flowed to the upstream main trough 81 is sent to the sand collection pit 6 . After that, similarly to the operation described above, the fluid is discharged in the order of the fourth nozzle header 9d, the stirring nozzle 62 and the upstream trough nozzle 83, the first nozzle header 9a, the stirring nozzle 62 and the upstream trough nozzle 83, thereby All the sand deposited on the bottom of the pond on the upstream side of the sand pit 6 is carried out to the outside of the settling basin 2 . The order in which the fluid is ejected from the nozzle headers 9a, 9b, 9d, and 9e may be arbitrary. However, if the sand deposited on the far side from the sand collection pit 6 is first flushed, the sand deposited on the side closer to the sand collection pit 6 along with the sand to be flushed flows into the main trough 8, whereupon the sand enters the main trough. It may become difficult to send the sand in the main trough 8 to the sand collection pit 6. Therefore, after the fluid is discharged from the second nozzle header 9b and the fifth nozzle header 9e on the side closer to the sand collection pit 6, the fluid is discharged from the first nozzle header 9a and the fourth nozzle header 9d on the side farther from the sand collection pit 6. is desired to be discharged.

After the sand accumulated on the upstream side is removed by the above operation, the sand accumulated in the downstream main trough 82 is flown into the sand collection pit 6 by discharging fluid from the stirring nozzle 62 and the downstream trough nozzle 84 for a certain period of time. After that, the ejection of the fluid from the stirring nozzle 62 and the downstream trough nozzle 84 is stopped, and the fluid is ejected from the ejection port 911 provided in the sixth nozzle header 9f for a certain period of time. After a certain period of time has passed, the ejection of fluid from the ejection openings 911 provided in the sixth nozzle header 9f is stopped. Then, fluid is discharged from the agitating nozzle 62 and the downstream main trough 82 for a certain period of time, and the sand that has flowed to the downstream main trough 82 is sent to the sand collection pit 6 . Next, in the same manner as described above, the third nozzle header 9c, the agitating nozzle 62, and the downstream trough nozzle 84 discharge the fluid in this order, so that all the sand deposited on the bottom of the pond on the downstream side of the sand collection pit 6 settles. It is carried out outside the pond 2 . Finally, by discharging a fluid from the pit sand collection nozzle 63, the sand deposited on the inclined surface 6b of the sand collection pit 6 is flowed to the deepest portion 6a. When all these operations are completed, the water supply pump 33 is stopped, and the sand pump 61 is also stopped after a predetermined time has elapsed.

In this embodiment, the amount of fluid pumped up by the sand pump 61 is set to be slightly larger than the amount of fluid pumped up by the water supply pump 33 when the sand removal operation described above is being performed. ing. Therefore, the sand pump 61 is repeatedly stopped and restarted a plurality of times while the removal operation is being performed. However, if the sand pump 61 is repeatedly driven and stopped, the life of the pump will be shortened due to the inrush current at the start of driving. As a countermeasure, the pumping capacity of the water supply pump 33 and the fluid pumping capacity of the sand pump 61 may be made close to each other to minimize the change in the water level during the sand removal operation. Further, when the water level sensor 99 detects that the water level has reached the middle water level MWL, the fluid may be additionally discharged from other nozzles in addition to the nozzles that are discharging the fluid at that time. By increasing the number of nozzles that discharge fluid, the load (restriction resistance) on the flow of fluid is reduced, so the amount of fluid sucked up by the water supply pump 33 is increased, and as a result, a large amount of fluid can be supplied to the settling basin 2. As a result, the low water level LWL is less likely to occur, and the number of times the sand pump 61 is stopped and restarted can be reduced. Here, the other nozzle is desirably the sand collecting nozzle 91 provided in the nozzle header to be discharged next. By ejecting the fluid from the nozzle header to be ejected next, the sand on the bottom surface to be washed next can be preliminarily washed away, so sand remaining can be further suppressed. Further, the fluid to be additionally discharged may be fluid stored in other equipment. Further, the sand pump 61 is not stopped even when the water level becomes low LWL, and instead of stopping the sand pump 61, in addition to the fluid pumped up by the water supply pump 33, fluid stored in other equipment is supplied to the settling basin 2. may be configured. In such a configuration, the supply of the fluid stored in other facilities to the settling basin 2 may be stopped when the water level reaches the second high water level HWL. By reducing the number of times the sand pump 61 is repeatedly stopped and driven, deterioration of the sand pump 61 can be suppressed and the life of the sand pump 61 can be extended.

Next, a modified example of the sand collecting means 9 will be described. In the modifications described below, differences from the embodiment shown in FIGS. will be described with reference numerals used so far, and redundant description will be omitted.

9(a) is a diagram showing a first modification of the supply pipe and the sand collection nozzle shown in FIG. 6, and FIG. 9(b) is a second modification of the supply pipe and the sand collection nozzle shown in FIG. It is a figure which shows.

In the first modification, the supply pipe 92 is not provided with a lap joint 934, and the supply pipe 92 and the branch pipe 932 are flange-connected, and the sand collection nozzle 91 is provided with a ball joint 912. The point is different from the example shown in FIG. 6(a). In FIG. 9A, the sand collecting nozzle 91 corresponding to the projecting wall Wa1 is indicated by a solid line, and the sand collecting nozzle 91 corresponding to the recessed wall Wa2 is indicated by a chain double-dashed line. In this modification, a ball joint 912 is provided between the supply pipe 92 and each outlet 911 . With this ball joint 912, the discharge direction of the fluid can be steplessly changed not only in the direction of rotation about the axis of the supply pipe 92, but also in various other directions. Therefore, the ejection direction can be finely adjusted for each ejection port 911 . A lap joint 934 may be arranged on the supply pipe 92 and a ball joint 912 may be provided on the sand collecting nozzle 91 . In this case, the lap joint 934 corresponds to an example of collective change means, and the ball joint 912 corresponds to an example of individual direction change means.

In the second modification, no lap joint 934 is arranged in the supply pipe 92, and the supply pipe 92 and the branch pipe 932 are flange-connected. It differs from the example shown in FIG. 6A in that a plurality of mounting portions 924 are formed. In FIG. 9B, the sand collecting nozzle 91 corresponding to the projecting wall Wa1 is indicated by a solid line, and the sand collecting nozzle 91 corresponding to the recessed wall Wa2 is indicated by a chain double-dashed line. In this modification, mounting portions 924 for the sand collecting nozzle 91 are formed at six locations in the circumferential direction of the supply pipe 92 . Accordingly, after the supply pipe 92 is fixed to the branch pipe 932, the sand collection nozzle 91 can be attached to any attachment portion 924 among the attachment portions 924 at six locations. Before the sand collection nozzle 91 is attached, plug members are attached to all attachment portions 924 . When attaching the sand collecting nozzle 91, the sand collecting nozzle 91 is attached after removing the plug member. Note that the lap joint 934 may be arranged on the supply pipe 92 and the mounting portion 924 may be formed on the supply pipe 92 . In this case, the lap joint 934 corresponds to an example of collective change means, and the mounting portion 924 corresponds to an example of individual direction change means. In this modified example, six mounting portions 924 are formed in the circumferential direction.

The present invention is not limited to the above embodiments and modifications, and can be modified in various ways within the scope of the claims. For example, in the present embodiment, the present invention is used in the settling basin 2 of the sewage treatment facility 1 into which sewage and rainwater flow, but it can also be applied to the settling basin of the rainwater treatment facility into which only rainwater flows. In addition, in the present embodiment, the sand deposited on the bottom surface 7 on the upstream side of the sand collection pit 6 is washed away, and then the sand deposited on the bottom surface 7 on the downstream side of the sand collection pit 6 is washed off. Sand deposited on the bottom surface 7 on the downstream side may be washed away.

According to this embodiment or its modification, the sand deposited on the bottom surface 7 can be flushed away with a fluid without leaving any residue. In addition, since the straight supply pipe 92 can be used even in a settling basin in which the left side wall Wa or the right side wall Wb is not formed linearly, the settling basin 2 can be provided at a low cost. In addition, even if the shape of the side wall W is unknown when the settling basin 2 is designed or when the supply pipe 92 is created, the discharge direction can be adjusted when the settling basin 2 is constructed. Flexible.

The following inventive concepts can also be extracted from the settling basin of this embodiment.
In a settling basin where the sand contained in the incoming water settles,
A groove provided in the pond bottom below the side wall and extending in a predetermined direction;
a bottom surface provided at the bottom of the pond and connected to the groove;
a plurality of discharge ports for discharging a fluid for flowing the sand settled on the bottom surface from the side wall toward the groove;
and a supply pipe provided with the discharge port,
The plurality of discharge ports include those that discharge fluid toward the center in the pond width direction from the axis of the supply pipe provided with the discharge ports, and those that discharge fluid toward the outside in the pond width direction from the axis of the supply pipe. A settling basin, characterized in that there is a thing that discharges a fluid through a settling basin.

In addition, the following concept of the invention can be extracted from the settling basin of the present embodiment.
In a settling basin where the sand contained in the incoming water settles,
A groove provided in the pond bottom below the side wall and extending in a predetermined direction;
a bottom surface provided at the bottom of the pond and connected to the groove;
a discharge port for discharging a fluid for flowing the sand that has settled on the bottom surface from the side wall toward the groove; a supply pipe,
The supply pipe has a first region extending from the side wall in the width direction of the pond with a first spacing, and a second region extending from the side wall in the width direction of the pool with a second spacing. ,
A settling basin, wherein the discharge port arranged in the first region and the discharge port arranged in the second region are capable of changing the discharge direction of the fluid independently of each other.

The number of ejection openings provided in the first region may be plural or may be one. When a plurality of ejection openings are provided in the first region, it is preferable that the ejection direction of the fluid from these ejection openings can be collectively changed. Also, the number of ejection openings provided in the second region may be plural or may be one. Even when a plurality of ejection openings are provided in the second region, it is preferable that the ejection direction of the fluid from these ejection openings can be collectively changed. Here, "changeable collectively" means, for example, that the portion of the first region and the portion of the second region of the supply pipe can rotate separately about the axial direction of the supply pipe. It is realized by In addition, rotatable portions may be provided at both end portions of the first region of the supply pipe, and rotatable portions may be provided at both end portions of the second region. The supply pipe may be a straight pipe or a pipe provided with a slightly curved portion.

The supply pipe is provided with a third region connecting the first region and the second region,
The discharge port provided in the third region may change the discharge direction of the fluid separately from the discharge ports provided in the first region and the discharge ports provided in the second region. good.

The third region may be an inclined region in which the distance from the side wall changes gradually in the extending direction, or may be a region in which the distance changes stepwise.

Also, the number of ejection openings provided in the third region may be plural or may be one. When a plurality of ejection openings are provided in the third region, it is preferable that the ejection direction of the fluid from these ejection openings can also be changed collectively. Here, "changeable collectively" means, for example, that the third area portion of the supply pipe is different from the first area portion and the second area portion of the supply pipe. It is realized by rotating about the axial direction.

In addition, the following concept of the invention can be extracted from the settling basin of the present embodiment.
In a settling basin where the sand contained in the incoming water settles,
A groove provided in the pond bottom below the side wall and extending in a predetermined direction;
a bottom surface provided at the bottom of the pond and connected to the groove;
a plurality of discharge ports arranged opposite to the side wall for discharging a fluid for flowing sand settled on the bottom surface from the side wall toward the groove;
The side wall has a protruding wall portion that protrudes toward the center in the width direction of the pond and extends in the predetermined direction, and a recessed wall portion that is recessed outward in the width direction of the pond and extends in the predetermined direction,
The discharge port is arranged to face each of the protruding wall portion and the recessed wall portion,
The ejection direction of the fluid ejected from the ejection port arranged to face the protruded wall portion is set to be different from the ejection direction of the fluid ejected from the ejection port arranged to face the recessed wall portion. A settling basin, characterized in that it comprises changeable direction changing means.

Furthermore, the following inventive concept can be extracted from the settling basin of this embodiment.
In a settling basin where the sand contained in the incoming water settles,
A groove provided in the pond bottom below the side wall and extending in a predetermined direction;
a bottom surface provided at the bottom of the pond and connected to the groove;
a supply pipe disposed facing the side wall and extending in the predetermined direction;
a plurality of discharge ports arranged in the supply pipe and discharging a fluid for flowing the sand settled on the bottom surface from the side wall toward the groove;
The side wall has a protruding wall portion that protrudes toward the center in the width direction of the pond and extends in the predetermined direction, and a recessed wall portion that is recessed outward in the width direction of the pond and extends in the predetermined direction,
The ejection port is arranged at a position facing the protruding wall and at a position facing the recessed wall,
The supply pipe is disposed between the ejection port arranged at a position facing the protruding wall portion and the ejection port arranged at a position facing the recessed wall portion in the direction in which the fluid is discharged from the discharge port. A settling basin characterized by comprising a direction changing means capable of changing the

Also, in this settling basin,
The side wall has an inclined wall portion formed between the projecting wall portion and the recessed wall portion and extending in a direction inclined with respect to the predetermined direction and the pond width direction,
The ejection port is also arranged at a position facing the inclined wall,
The supply pipe is arranged between a discharge port arranged to face the protruding wall portion and a discharge port arranged to face the inclined wall portion so as to direct the discharge direction of the fluid discharged from the discharge port. comprising a changeable first direction changing means;
A discharge direction of fluid discharged from the discharge ports can be changed between a plurality of discharge ports arranged to face the recessed wall portion and a discharge port arranged to face the inclined wall portion. A second direction changing means may be provided.

In addition, the following inventive concepts can also be extracted from the settling basin of this embodiment.
In a settling basin where the sand contained in the incoming water settles,
A groove provided in the pond bottom below the side wall and extending in a predetermined direction;
a bottom surface provided at the bottom of the pond and connected to the groove;
a plurality of discharge ports for discharging a fluid for flowing the sand settled on the bottom surface from the side wall toward the groove;
collective direction changing means capable of collectively changing the discharge direction of the fluid discharged from at least two of the plurality of discharge ports;
and individual direction changing means capable of changing the discharge direction of the fluid discharged from each discharge port.

In addition, even if the constituent elements are included only in the descriptions of the embodiments and modifications described above, the constituent elements may be applied to the embodiments and other modifications.

2 Grit basin 7 Bottom surface 8 Main trough 911 Discharge port 92 Supply pipe 93 Main pipe 912 Ball joint 924 Mounting part

Claims (4)

In a settling basin where the sand contained in the incoming water settles,
A groove provided in the pond bottom below the side wall and extending in a predetermined direction;
a bottom surface provided at the bottom of the pond and connected to the groove;
a supply pipe disposed facing the side wall and extending in the predetermined direction;
a plurality of discharge ports arranged in the supply pipe and discharging a fluid for flowing sand settled on the bottom surface from the side wall side toward the groove;
The side wall has a protruding wall portion that protrudes toward the center in the width direction of the pond and extends in the predetermined direction, and a recessed wall portion that is recessed outward in the width direction of the pond and extends in the predetermined direction,
The ejection port is arranged at a position facing the protruding wall and at a position facing the recessed wall,
The supply pipe is located between a first outlet arranged at a position facing the projecting wall and a second outlet arranged at a position facing the recessed wall among the plurality of outlets. and a direction changing means capable of changing the ejection direction of the fluid ejected from the first ejection port and the ejection direction of the fluid ejected from the second ejection port to different directions. Settling pond. Having a mother pipe that supplies fluid to the supply pipe,
2. The settling basin according to claim 1, wherein said supply pipe is rotatable with respect to said mother pipe about the axial direction of said supply pipe. 2. The settling basin according to claim 1, wherein said discharge port is capable of changing the discharge direction of the fluid by means of a ball joint disposed between said supply pipe and said discharge port. In a settling basin where the sand contained in the incoming water settles,
A groove provided in the pond bottom below the side wall and extending in a predetermined direction;
a bottom surface provided at the bottom of the pond and connected to the groove;
a discharge port for discharging a fluid for flowing the sand settled on the bottom surface from the side wall toward the groove;
a supply pipe in which the discharge port is detachably provided;
The settling basin, wherein the supply pipe has a plurality of mounting portions to which the discharge ports are mounted in a circumferential direction of the supply pipe, so that the discharge direction of the fluid discharged from the discharge ports can be changed.

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