Scum transfer device

Abstract

To provide a scum transfer device capable of moving scum even when a bridge has formed.SOLUTION: A scum transfer device 5 for moving scum floating on a water surface in a predetermined moving direction includes a hollow body 51 extending along the direction of movement and a discharge port 521 for jetting fluid into an internal space S defined by an inner peripheral surface 51a of the hollow body 51. The hollow body 51 has a first right opening 511R and a first left opening 512L formed on the side of the hollow body 51 and extending along the moving direction, and the first right opening 511R and the first left opening 512L function as outlets for releasing fluid jetted from the discharge port 521 into the internal space S to the outside of the internal space S. The discharge port 521 is positioned within the internal space S at the upstream end of the hollow body 51 and discharges fluid along the axial direction of the hollow body 51. The discharge port 521 has a flattened elongated hole shape.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a scum moving device that moves scum floating on the water surface in a predetermined moving direction. [Background technology]

[0002] Scum, which interferes with the purification process, floats on the water surface of sedimentation basins installed in wastewater treatment facilities and in conduits that distribute wastewater to the sedimentation basins. Hereinafter, the sedimentation basins and conduits are collectively referred to as conduits, etc. Leaving scum floating in conduits, etc., for a long period of time can lead to a deterioration in the quality of the wastewater. For this reason, conduits, etc., may be equipped with a scum transfer device that transfers the scum and a scum removal device that removes the transferred scum. One proposed scum transfer device is one that has multiple nozzles placed above the conduit, etc., and uses the force of water ejected from the nozzles to transfer the scum toward the scum removal device. Examples of such scum transfer devices are described in Patent Documents 1 and 2, for example. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-143843 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-136244 Summary of the Invention [Problem to be solved by the invention]

[0004] However, scum floating on the water surface can sometimes form bridges between the side walls of a conduit or other structure. A bridge, also known as arching, refers to the state in which scum spans the side walls of a conduit or other structure. The formation of a bridge impedes the movement of the scum. When a bridge is formed, even if fluid is discharged from multiple nozzles as described in Patent Documents 1 and 2, small holes are created in the bridge where the fluid discharged from the nozzles directly hits, and the scum cannot be moved toward the scum removal device. Furthermore, although the fluid discharged from the nozzles generates a certain amount of water flow locally near each nozzle, the water flow weakens as it moves away from the holes in the bridge, making it difficult to move the scum over long distances.

[0005] SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a scum moving device that can move scum even when a bridge is formed. [Means for solving the problem]

[0006] The scum moving device of the present invention that solves the above-mentioned object is a scum moving device that moves scum floating on the water surface in a predetermined moving direction, a hollow body extending along the movement direction; a discharge port for discharging a fluid into an internal space defined by an inner circumferential surface of the hollow body, the hollow body has an opening formed in a side portion thereof, the opening extending along the movement direction, the opening acts as a discharge port for discharging the fluid discharged from the discharge port into the internal space to the outside of the internal space, The discharge port is located within the internal space at the upstream end of the hollow body, discharges the fluid in the axial direction of the hollow body, and is characterized by being in the shape of a flattened elongated hole.

[0007] In this scum moving device, the discharge port may be an elongated hole that is collapsed in the height direction and widens in the width direction. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a scum moving device that can move scum even when a bridge is formed. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view of a water conduit equipped with a scum moving device according to an embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a cross-sectional view of the water conduit shown in FIG. 1 taken along the line AA. [Figure 3] 1. (a) is a BB cross-sectional view of the hollow body shown in FIG. 1, and (b) is a CC cross-sectional view of the hollow body shown in FIG. [Figure 4] 4(a) is an enlarged view of a portion D in FIG. 2, and FIG. 4(b) is a view seen from the direction of arrow E in FIG. 4(a). [Figure 5] 5 is a plan view showing the operation of the scum moving device of the present embodiment. FIG. [Figure 6] 1, showing a water conduit equipped with a scum moving device according to a second embodiment. FIG. [Figure 7] 1, showing a conduit equipped with a scum moving device according to a third embodiment. FIG. [Figure 8] FIG. 8 is an FF cross-sectional view of the water conduit shown in FIG. 7. [Figure 9] 8A is an enlarged view showing a portion G in FIG. 8A, and FIG. 8B is a cross-sectional view taken along the line HH in FIG. 8A. [Figure 10] FIG. 10 is a plan view showing the operation of the scum moving device of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below with reference to the accompanying drawings. The scum removal device according to the present invention is disposed in a conduit and moves scum on the water surface of the conduit toward a scum removal device.

[0011] Fig. 1 is a plan view of a conduit equipped with a scum moving device according to one embodiment of the present invention. Fig. 1 shows the portion below the ceiling of the conduit. Fig. 1 also shows a portion of the sedimentation basin.

[0012] As shown in FIG. 1 , the conduit 1 of this embodiment is a rectangular facility in plan view, bounded by a left wall 11, a right wall 12, an upstream wall 13, and a downstream wall 14. Wastewater, such as sewage and rainwater treated in a settling basin (not shown), flows into the conduit 1. The conduit 1 receives the inflowing wastewater and distributes it to multiple settling basins 9 for inflow. The conduit 1 receives wastewater from the left side in FIG. 1 (see the white arrows in FIG. 1 ). The wastewater received by the conduit 1 flows toward the right side in FIG. 1 between the left wall 11 and the right wall 12. Hereinafter, the upstream side of the flow of the received wastewater will be simply referred to as the upstream side, the downstream side of the flow of the wastewater will be simply referred to as the downstream side, and the direction from the upstream side to the downstream side will be referred to as the movement direction. Furthermore, the direction to the left as viewed from the upstream side (upward in FIG. 1) is referred to as the left direction, and the direction to the right as viewed from the upstream side (downward in FIG. 1) is referred to as the right direction. Additionally, when the left and right directions are not distinguished, they are referred to as the width direction.

[0013] An inlet 121 is formed for each sedimentation basin 9 in the middle of the right side wall 12 in the height direction, for allowing the wastewater in the water conduit 1 to flow into each sedimentation basin 9. In addition, an inlet door 122 is provided for each inlet 121. The inlet door 122 opens and closes the inlet 121 by moving up and down along the right side wall 12. The inlet door 122 is moved up and down by a drive mechanism (not shown) to change the inlet area of ​​the inlet 121, thereby making it possible to adjust the amount of wastewater flowing into the sedimentation basin 9 connected to that inlet 121.

[0014] A scum removal device 3 and a scum moving device 5 are disposed in the conduit 1. The scum removal device 3 is provided at the downstream end of the conduit 1. The scum removal device 3 has a scum pit 31, a scum pump 32, a scum pit weir 33, and a gate 34. The scum pit 31 is separated from other parts of the conduit 1 by the scum pit weir 33. The scum pump 32 is disposed within the scum pit 31. The scum pit weir 33 is a weir that has the same height as the left side wall 11 and the right side wall 12. The scum pit weir 33 has a scum intake port 331 formed at a predetermined height. Furthermore, upstream of the scum intake port 331, a gate 34 is disposed that moves up and down along the upstream side of the scum pit weir 33. This gate 34 is an example of a movable weir. The scum intake port 331 and gate 34 will be described later.

[0015] The scum moving device 5 has a hollow body 51, a nozzle 52, and a nozzle pipe 53. The hollow body 51 is disposed at the center of the water conduit 1 in the width direction. The hollow body 51 is a hollow, long member that extends along the moving direction from near the upstream wall 13 to near the scum pit weir 33. The hollow body 51 of this embodiment is formed by connecting two first pipes 511 and two second pipes 512 alternately along the moving direction by flange joints 513. The upstream end 51u and downstream end 51d of the hollow body 51 are open. However, one or both of the upstream end 51u and downstream end 51d of the hollow body 51 may be closed.

[0016] The tip side of the nozzle 52 is disposed within the internal space S (see FIG. 4) formed by the hollow body 51. The rear end of the nozzle 52 is connected to a nozzle pipe 53. The nozzle pipe 53 is fixed to the left side wall 11 by a fixture (not shown) attached to the left side wall 11. The nozzle pipe 53 is supplied with wastewater pumped up from the sedimentation tank 9. However, the discharged wastewater may be pumped up from a source other than the sedimentation tank 9. Furthermore, water from another pond or tap may be used instead of wastewater. Furthermore, a mixed fluid in which a liquid and a gas are mixed may be used. When a mixed fluid is used, a bubble generator may be provided midway along the nozzle pipe 53. The wastewater supplied to the nozzle pipe 53 is discharged from the nozzle 52 toward the internal space S.

[0017] FIG. 2 is a cross-sectional view of the water conduit shown in FIG. 1 taken along the line AA.

[0018] As shown in Figure 2, a flow control valve 531 and an electric valve 532 are installed in the upstream portion of the nozzle pipe 53 in the sewage supply direction. The electric valve 532 is opened at a predetermined time to move the scum in the conduit 1 in the movement direction and remove it from the conduit 1. When the electric valve 532 is opened, sewage at a flow rate adjusted by the flow control valve 531 passes through the electric valve 532 and is supplied to the nozzle 52.

[0019] The hollow body 51 is fixed at a predetermined position in the conduit 1 by three support members 161. Each of the three support members 161 is suspended from the ceiling 16 of the conduit 1. The support members 161 are made of stainless steel rods. The lower end portion of each support member 161 is attached to a flange joint 513. The suspension position of the support member 161 may be shifted in the direction of movement, and the lower end portion of the support member 161 may be attached to the first pipe 511 or the second pipe 512. Furthermore, instead of the support members 161, legs supporting the hollow body 51 may be installed on the bottom surface of the conduit 1.

[0020] As shown in Figure 2, the water level in Conduit 1 fluctuates depending on various conditions such as weather. Figure 2 shows the highest water level (HWL), the lowest water level (LWL), and the standard water level (SWL). The difference between the high water level (HWL) and the low water level (LWL) is 500 mm. The standard water level (SWL) is the water level exactly halfway between the high water level (HWL) and the low water level (LWL), and is also the average water level in Conduit 1.

[0021] The scum intake port 331 formed in the scum pit weir 33 has its upper end located above the high water level (HWL) and its lower end located below the low water level (LWL). A gate drive device 333 is installed on the aboveground portion of the conduit 1. The gate 34 moves up and down when driven by the gate drive device 333 in response to commands from a control device that controls the conduit 1. The gate 34 is normally positioned to block the entire scum intake port 331. The gate 34 lowers to a position corresponding to the water level in the conduit 1 at a predetermined time to move the scum in the conduit 1 in the movement direction and remove it from the conduit 1. At this time, by opening the motor-operated valve 532, the scum floating in the conduit 1 can be moved toward the scum removal device 3 and flow into the scum pit 31 through the scum intake port 331. In this embodiment, a movable weir type scum removal device 3 with a gate 34 that moves up and down is used, but a tipping weir type scum removal device 3 or a scum skimmer type scum removal device 3 may also be used. The scum that flows into the scum pit 31 is sucked up by a scum pump 32 and sent to the outside of the water conduit 1.

[0022] Figure 3(a) is a BB cross-sectional view of the hollow body shown in Figure 1, and (b) is a CC cross-sectional view of the hollow body shown in Figure 1. In Figures 3(a) and 3(b), the hatching and background indicating the cross section are omitted.

[0023] As shown in FIG. 3(a), the first tubular body 511 constituting the hollow body 51 has a cross-sectional shape of approximately 5 / 6 of a circle with a first right opening 511R on its right side. That is, the cross-sectional shape of the first tubular body 511 is C-shaped. This first right opening 511R corresponds to an example of an opening. The first tubular body 511 is formed from a 3 mm thick stainless steel plate into an arc-shaped cross-section with an inner diameter of 150 mm. The upstream and downstream ends of the first tubular body 511 are open. The first right opening 511R extends over the entire length of the first tubular body 511 along the movement direction. The opening height of the first right opening 511R is 80 mm. The center height of the first right opening 511R coincides with the height of the axis 511c of the first tubular body 511. That is, the first right opening 511R is located directly to the right of the first tubular body 511. However, the first pipe 511 may be rotated about the axis 511c as long as a portion of the first right opening 511R is at a height position that coincides with the height of the axis 511c of the first pipe 511. In such a case, the first right opening 511R is disposed diagonally above or below the right of the first pipe 511. Furthermore, of the two first pipes 511, the first pipe 511 disposed on the upstream side of the hollow body 51 and the first pipe 511 disposed on the downstream side may be disposed at different angles about the axis 511c so that the positions of the first right openings 511R are different. This first right opening 511R acts as a discharge port that discharges the wastewater discharged from the discharge port 521 (see FIG. 4) into the internal space S to the outside of the internal space S.

[0024] As shown in FIG. 3(b), the second tubular body 512 has a cross-sectional shape of approximately 5 / 6 of a circle with a first left opening 512L on its left side. That is, the cross-sectional shape of the second tubular body 512 is an inverted C-shape. The first left opening 512L corresponds to an example of an opening. The second tubular body 512 is formed from a 3 mm thick stainless steel plate into an arc-shaped cross-section with an inner diameter of 150 mm. The upstream and downstream ends of the second tubular body 512 are open. The first left opening 512L extends along the entire length of the second tubular body 512 in the movement direction. The opening height of the first left opening 512L is 80 mm. The center height of the first left opening 512L coincides with the height of the axis 512c of the second tubular body 512. That is, the first left opening 512L is located directly to the left of the second tubular body 512. However, as long as a portion of the first left opening 512L is positioned at the same height as the axis 512c of the second pipe 512, the second pipe 512 may be rotated about the axis 512c. In such a case, the first left opening 512L is positioned diagonally above or below the left of the second pipe 512. Furthermore, the second pipe 512 disposed upstream of the hollow body 51 and the second pipe 512 disposed downstream of the hollow body 51 may be positioned at different angles about the axis 512c so that the positions of the first left openings 512L are different. This first left opening 512L also functions as an outlet for discharging wastewater discharged into the internal space S. The second pipe 512 is structurally identical to the first pipe 511 and is rotated 180 degrees about the axis 512c relative to the first pipe 511.

[0025] An axis 511c of the first tube 511 shown in FIG. 3(a) and an axis 512c of the second tube 512 shown in FIG. 3(b) are aligned. Therefore, the inner circumferential surface 511a of the first tube 511 and the inner circumferential surface 512a of the second tube 512 are continuous in the direction of movement. Hereinafter, when there is no need to distinguish between the axis 511c of the first tube 511 and the axis 512c of the second tube 512, they will be referred to as the axis 51c of the hollow body 51. Furthermore, when there is no need to distinguish between the inner circumferential surface 511a of the first tube 511 and the inner circumferential surface 512a of the second tube 512, they will be referred to as the inner circumferential surface 51a of the hollow body 51. The space that is continuous in the direction of movement across the first tube 511 and the second tube 512 is the internal space S. In other words, the internal space S is defined by the inner peripheral surface 51a of the hollow body 51. Therefore, the internal space S is a space whose upper and lower ends are closed and whose left or right end is open.

[0026] The height of the first right opening 511R is preferably ⅔ or less and ⅕ or more of the inner diameter of the first pipe 511. Similarly, the height of the first left opening 512L is preferably ⅔ or less and ⅕ or more of the inner diameter of the second pipe 512. If the height of the first right opening 511R or the first left opening 512L exceeds ⅔ of the inner diameter of the first pipe 511 or the inner diameter of the second pipe 512, when the wastewater is discharged into the internal space S from a discharge port 521 (see FIG. 4 ), which will be described later, the amount of wastewater discharged to the outside of the internal space S from the first right opening 511R or the first left opening 512L in the downstream portion of the internal space S may be too small. Conversely, if the height of the first right opening 511R or the first left opening 512L is less than 1 / 5 of the inner diameter of the first pipe 511 or the inner diameter of the second pipe 512, the amount of wastewater discharged from the first right opening 511R or the first left opening 512L to the outside of the internal space S may become too small. In that case, there is a risk that the scum cannot be moved in the movement direction.

[0027] Fig. 4(a) is an enlarged view of part D in Fig. 2, and Fig. 4(b) is a view seen from the arrow E in Fig. 2(a). Note that hatching indicating a cross section is omitted in Fig. 4(b).

[0028] As shown in Figures 4(a) and 4(b), the tip of the nozzle 52 enters the internal space S formed by the hollow body 51 from the upstream end 51u of the hollow body 51. The tip of the nozzle 52 has an elongated hole shape formed by flattening a pipe with an inner diameter of 80 mm from above and below. The nozzle 52 can be easily made by simply flattening the tip of a round pipe. An outlet 521 is formed at the tip of the nozzle 52. The wastewater supplied to the nozzle 52 from the nozzle piping 53 (see Figure 2) is discharged from the outlet 521 in the direction of movement. This wastewater discharged from the outlet 521 corresponds to an example of a fluid. The wastewater discharged from the outlet 521 forms a water flow in the internal space S at a speed corresponding to the discharge flow rate, and is then discharged to the outside of the internal space S from the first right opening 511R or the first left opening 512L. Furthermore, a portion of the wastewater discharged from the discharge port 521 is discharged downstream from the downstream end 51d of the hollow body 51 (see FIG. 1). The nozzle 52 may be a round pipe, but by forming it into a flattened elongated hole, the discharge pressure of the wastewater passing through the nozzle 52 and discharged from the discharge port 521 can be increased. The discharge port 521 may be a flattened shape that is long in the vertical or diagonal direction, but by forming it into a flattened shape that is long in the horizontal direction as shown in FIG. 4(b), the discharged wastewater is less likely to diffuse vertically but is more likely to diffuse widthwise. This makes it easier for the wastewater to be discharged outside the internal space S from the first right opening 511R and the first left opening 512L.

[0029] As shown in FIG. 4(a), the discharge port 521 is located within the internal space S at the upstream end 51u of the hollow body 51. This discharge port 521 discharges wastewater in the direction of movement. Because the discharge port 521 is located within the internal space S, all of the wastewater discharged from the discharge port 521 can be discharged into the internal space S. Furthermore, because the upstream end 51u of the hollow body 51 is open, when the first right opening 511R and the first left opening 512L are submerged, as described below, the flow of wastewater discharged from the discharge port 521 sucks wastewater outside the internal space S into the internal space S from the upstream end 51u of the hollow body 51. Therefore, a volume of wastewater greater than the volume of water discharged from the discharge port 521 can be supplied into the internal space S. However, the discharge port 521 does not have to extend into the internal space S as long as it can discharge wastewater into the internal space S. For example, the discharge port 521 may be located on a surface defined by the upstream end 51u of the hollow body 51, i.e., at the same position as the upstream end 51u. Furthermore, if the discharge outlet 521 is located upstream of the internal space S and far away from the internal space S, there is a risk that some of the sewage discharged toward the internal space S will not flow into the internal space S, so if it is located upstream of the internal space S, it is desirable to place it close to the upstream end 51u.

[0030] As shown in FIG. 4(b), the center 521c of the outlet 521 coincides with the axial center 51c of the hollow body 51. The direction of the wastewater discharged from the outlet 521 is along the axial center 51c of the hollow body 51. The axial center 51c of the hollow body 51 and the center 521c of the outlet 521 may be positioned differently, and the direction of the wastewater discharge may be slightly different from the axial center 51c of the hollow body 51. However, by aligning the axial center 51c of the hollow body 51 with the center 521c of the outlet 521 and aligning the discharge direction with the axial center 51c, it is possible to minimize the possibility of the wastewater discharged from the outlet 521 colliding with the inner circumferential surface 51a of the hollow body 51, thereby weakening the flow of the discharged wastewater. The maximum width of the outlet 521 is 117 mm, and the maximum height is 18 mm. The maximum height of the discharge outlet 521 is desirably lower than the opening height of the first right opening 511R and the opening height of the first left opening 512L. Furthermore, the discharge outlet 521 is desirably disposed between the upper and lower ends of the first right opening 511R and the first left opening 512L (see FIG. 3(b)) in the height direction. This makes it easier for the wastewater discharged from the discharge outlet 521 to be released to the outside of the internal space S from the first right opening 511R and the first left opening 512L while maintaining the momentum with which it was discharged from the discharge outlet 521.

[0031] Fig. 5 is a plan view showing the operation of the scum moving device of this embodiment. Fig. 5 mainly shows the operation of the wastewater discharged from the first pipe. In addition, the inlet 121 and the inlet door 122 to the sedimentation basin are not shown.

[0032] The action of sewage discharged from the discharge port 521 will be described with reference to FIGS. 2 and 5. When sewage is discharged from the discharge port 521 in the direction of movement, the sewage generates a fluid flow in the internal space S (see FIG. 4) in the direction of movement. A portion of the sewage discharged from the discharge port 521 into the internal space S is discharged from the first right opening 511R of the first pipe 511 at an angle slightly inclined to the right with respect to the direction of movement, as indicated by the multiple arrows pointing diagonally downward to the right in FIG. 5. Another portion of the sewage discharged into the internal space S is discharged from the first left opening 512L of the second pipe 512 at an angle slightly inclined to the left with respect to the direction of movement. The action caused by the sewage discharged from the first left opening 512L is similar to that of the sewage discharged from the first right opening 511R, although the action is symmetrical with respect to a vertical plane passing through the axis 51c of the hollow body 51, and therefore will not be described again. The wastewater in the internal space S that has not been discharged from the first left opening 512L and the first right opening 511R is discharged from the downstream end of the hollow body 51 in the movement direction.

[0033] If scum spans the left and right walls 11 and 12 of the conduit 1 to form a bridge, the bridge will be destroyed by the sewage discharged from the first right opening 511R. The scum that made up the destroyed bridge will then move in the direction of movement due to the water currents that occur near the water surface of the conduit 1. The manner in which the bridge is destroyed and the scum moves will differ slightly depending on the water level in the conduit 1, so the destruction and movement of the bridge at each water level will be explained in order.

[0034] As shown in FIG. 2, when the water level in the water conduit 1 is at the low water level (LWL), the hollow body 51 is in a fully exposed state, with the entire first right opening 511R exposed to the atmosphere. This fully exposed state corresponds to an example of an exposed state. As shown in FIG. 5, the wastewater released from the first right opening 511R flies through the atmosphere in the direction of movement and falls toward the water surface. The wastewater then falls into a first vicinity area N1, which is the area near the first pipe 511 on the upstream side, and a second vicinity area N2, which is the area near the first pipe 511 on the downstream side. As a result, the scum forming the bridge between the first vicinity area N1 and the second vicinity area N2 collapses, destroying the bridge. The first vicinity area N1 and the second vicinity area N2 are each elongated regions extending along the length of the first right opening 511R in the direction of movement, and are indicated by cross-hatching in FIG. 5. The scum that formed the bridge in the first vicinity region N1 and the second vicinity region N2 becomes floating scum on the water surface. Furthermore, when the released wastewater reaches the water surface, a water current and waves are formed near the water surface in the direction of movement. The floating scum moves in the direction of movement due to the formed water current. The formed waves gradually destroy the scum masses that formed the bridge around the first vicinity region N1 and the second vicinity region N2. Hereinafter, the scum masses that formed the bridge are referred to as residual bridges. In particular, residual bridges downstream of the first vicinity region N1 and the second vicinity region N2 are easily destroyed by the collision of the water current with waves. Furthermore, the residual bridges on both sides of the width direction of the first vicinity region N1 and the second vicinity region N2 are released from their state of spanning between the left wall 11 and the right wall 12 due to the destruction of the bridges, making them more likely to flow down. Similarly, the sewage discharged from the first left opening 512L also destroys the bridge, making it easier for the remaining bridge between the first vicinity region N1 and the second vicinity region N2 to flow down. As a result, the remaining bridge is destroyed along the movement direction, connecting the first vicinity region N1 and the second vicinity region N2. Furthermore, the bridge is also destroyed downstream of the second vicinity region N2, forming a flow path that allows floating scum to move to the scum removal device 3.Furthermore, the bridges formed near the flow path are gradually destroyed by the waves that form, turning into floating scum, which is drawn into the flow path and moves in the direction of movement with the water current.

[0035] When the water level in the culvert 1 is at the high water level HWL shown in FIG. 2 , the hollow body 51 is submerged, with the entire first right opening 511R shown in FIG. 5 positioned below the water surface. The wastewater released into the water from the first right opening 511R creates a water flow within the culvert 1, generating waves near the water surface. Since the expected water level fluctuation is 500 mm as described above, even in the submerged state, the first right opening 511R does not become deeply submerged or significantly separated from the water surface. In this embodiment, the upper end of the first right opening 511R does not become more than 210 mm above the water surface. The water flow generated by the wastewater released from the first right opening 511R is stronger than the water flow generated when the hollow body 51 is fully exposed, as described above. Furthermore, higher waves are formed compared to the fully exposed state. This strong water flow, accompanied by high waves, collides with the bridge, destroying it. The wavy water flow travels from the vicinity of the first right opening 511R at a slight rightward angle relative to the direction of movement, destroying bridges in the first vicinity region N1 and the second vicinity region N2 in the early stages after discharge. Then, as in the fully exposed state, the wavy water flow forms a flow path along the direction of movement that allows floating scum to move to the scum removal device 3. The destroyed residual bridges become scum floating on the water surface and move in the formed flow path along the direction of movement due to the water flow. As in the fully exposed state, the remaining bridges on both sides of the width direction of the first vicinity region N1 and the second vicinity region N2 are released from their bridge spanning state between the left wall 11 and the right wall 12 by the destruction of the bridges, making them more likely to flow down. Furthermore, because the sewage discharged from the first left opening 512L also destroys bridges, the remaining bridge between the first vicinity region N1 and the second vicinity region N2 also more likely to flow down. When a mixed fluid of liquid and gas is discharged from the discharge port 521, the mixed fluid is released from the first right opening 511R. When the mixed fluid is released while the device is submerged, the gas contained in the mixed fluid makes it easier for the released mixed fluid to rise toward the water surface, generating a stronger water current and higher waves on the water surface.

[0036] When the water level in the water conduit 1 is at the standard water level SWL shown in FIG. 2, the hollow body 51 is in a semi-exposed state, with the lower side of the first right opening 511R shown in FIG. 5 positioned below the water surface and the upper side exposed to the atmosphere. This semi-exposed state is also an example of an exposed state. In this semi-exposed state, sewage is discharged from both the upper side and the lower side of the first right opening 511R. The sewage discharged into the atmosphere from the upper side of the first right opening 511R produces the same effect as in the fully exposed state. Furthermore, the sewage discharged into the water from the lower side of the first right opening 511R produces the same effect as in the submerged state. The amount of sewage discharged from the upper side of the first right opening 511R and the amount of sewage discharged from the lower side of the first right opening 511R are each less than the amounts discharged in the submerged and fully exposed states. Therefore, when viewed individually, each effect is weaker than the submerged and fully exposed states. However, by combining the effects of the sewage released in both the submerged and fully exposed states, the bridge can be destroyed, forming a flow path, and moving the scum floating on the water surface to the scum removal device 3, just as in the submerged and fully exposed states.

[0037] The flow rate of wastewater discharged from the discharge port 521 is set appropriately within the range of 300 to 3,000 liters per minute, depending on the opening frequency, the size of the conduit 1, and other factors. If the flow rate is less than 300 liters per minute, the amount of wastewater discharged from the first right opening 511R and the first left opening 512L may be too small to adequately move the scum. Furthermore, if the flow rate exceeds 3,000 liters per minute, a large pump must be used to suck up wastewater from the settling tank and deliver it to the discharge port 521, making the scum transfer device 5 expensive. In addition, the power consumption required to drive the pump increases. Furthermore, if the discharge rate exceeds 3,000 liters per minute, too much wastewater is discharged into the conduit 1, causing a large amount of wastewater to flow into the scum pit 31 (see Figure 2) along with the scum, lowering the scum concentration and complicating scum treatment in subsequent processes.

[0038] The discharge flow velocity of the wastewater discharged from the discharge port 521 is preferably 8 m / sec or greater. If the discharge velocity is less than 8 m / sec, the water flow formed by the fluid discharged from the first right opening 511R and the first left opening 512L will be weak, and the remaining bridges downstream of the first vicinity region N1 and the second vicinity region N2 will not be broken, or even if they are broken, it will take too long. Furthermore, the discharge pressure of the wastewater discharged from the discharge port 521 is preferably 0.05 MPa or greater and 0.3 MPa or less. If the discharge pressure is less than 0.05 MPa, the water pressure applied to the discharge port 521 when submerged and pressure loss in the discharge nozzle may prevent water from being discharged from the discharge port 521. If the discharge pressure is greater than 0.3 MPa, the amount of wastewater discharged from the downstream end 51d of the hollow body 51 without being discharged from the first right opening 511R and the first left opening 512L will increase, which may prevent the bridges from being broken in the first vicinity region N1 or the second vicinity region N2 and prevent the formation of a flow path for scum to move. Furthermore, in order to generate a discharge pressure greater than 0.3 MPa, it becomes necessary to use a large pump for sending the wastewater to the discharge port 521, which makes the scum moving device 5 expensive. In addition, the amount of power consumed to drive the pump also increases.

[0039] According to this embodiment, the wastewater discharged from the discharge port 521 is discharged from the first right opening 511R and the first left opening 512L. The discharged wastewater destroys bridges formed by scum over a range corresponding to the length of the first right opening 511R and the first left opening 512L along the direction of movement. The discharged wastewater also generates a water flow accompanied by waves, destroying any remaining bridges around the destroyed bridges. Residual bridges downstream of the water flow are particularly susceptible to destruction. This creates a flow path on the water surface through which scum can move. The formation of the flow path allows scum to move a long distance along the direction of movement. Specifically, discharging wastewater from the first right opening 511R and the first left opening 512L, which extend in the direction of movement, generates a water flow accompanied by waves, destroying bridges formed in the culvert 1 and forming a flow path that moves the scum in the direction of movement. The water flow then transports the scum along the flow path, allowing it to reach the scum removal device 3 and be removed from the culvert 1. Furthermore, since a single hollow body 51 extends from near the upstream wall 13 to near the scum pit weir 33 and only one nozzle 52 is disposed at the upstream end 51u of the hollow body 51, this prevents the problem of scum entanglement around the nozzle and blocking scum movement at the nozzles, as compared with conventional scum moving devices with multiple nozzles. Furthermore, in this embodiment, the first right openings 511R and the first left openings 512L are alternately disposed along the moving direction, forming flow paths on both sides of the hollow body 51 in the width direction for moving scum downstream. This allows scum to be moved in the moving direction without increasing the number of hollow bodies 51, even in a water conduit 1 with a relatively wide width. Note that the initial residual bridge discharged from the first right opening 511R and the first left opening 512L may adhere to either the left wall 11 or the right wall 12 due to the viscosity of the scum. However, unlike the state where the residual bridge is suspended between the left side wall 11 and the right side wall 12, the residual bridge adheres to only one of the left side wall 11 or the right side wall 12, and therefore can be easily peeled off from the left side wall 11 or the right side wall 12.Therefore, the residual bridge that has been caught in the water current caused by the fluid discharged on the upstream side or the scum flowing from the upstream side and that has adhered to either the left side wall 11 or the right side wall 12 can also be caused to flow down over time. In this embodiment, the first right opening 511R and the first left opening 512L are arranged alternately and are not arranged in positions that overlap in the movement direction, but the first right opening 511R and the first left opening 512L may be arranged to overlap partially in the movement direction.

[0040] Next, a scum moving device 5 according to a second embodiment will be described. In the following description, components having the same names as components described so far will be assigned the same reference numerals as those used so far, and duplicated descriptions may be omitted.

[0041] FIG. 6 is a plan view similar to FIG. 1 of a water conduit equipped with a scum moving device of the second embodiment.

[0042] The conduit 1 shown in FIG. 6 differs from the conduit 1 shown in the previous embodiment in that the length of the conduit 1 in the movement direction is approximately twice as long and that two scum moving devices 5 are provided side by side in the movement direction. As shown in FIG. 6, four settling basins 9 are connected to this conduit 1. The two scum moving devices 5 have the same configuration. The hollow body 51 of the upstream scum moving device 5 extends along the movement direction from near the upstream wall 13 to the center of the conduit 1 in the movement direction. The hollow body 51 of the downstream scum moving device 5 extends along the movement direction from the center of the conduit 1 in the movement direction to near the scum pit weir 33, with a small gap between it and the upstream hollow body 51. A discharge port 521 (see FIG. 4) is provided at the upstream end 51u of each of the two hollow bodies 51.

[0043] In the conduit 1 equipped with the scum moving device 5 of this second embodiment, in addition to the effects of the above-described embodiments, by providing two scum moving devices 5 aligned in the direction of movement and discharging wastewater from the outlets 521 provided in each, a flow path extending from the upstream side to the downstream side along the direction of movement can be formed, even if the length of the conduit 1 in the direction of movement is long. Then, by the same action as the scum moving device 5 described above, each scum moving device 5 breaks bridges, allowing the scum to reach the scum removal device 3 and remove the scum from the conduit 1. Instead of providing two scum moving devices 5, a hollow body 51 extending from near the upstream wall 13 to near the scum pit weir 33 may be installed, with a first nozzle 52 discharging wastewater in the direction of movement located near the upstream wall 13 and a second nozzle 52 similarly discharging wastewater in the direction of movement located in the middle of the hollow body 51. That is, a scum moving device 5 having multiple nozzles 52 spaced apart along the extension direction of the hollow body 51 may be used. In this case, a hole can be drilled in the middle of the hollow body 51 and the second nozzle 52 can be inserted therein. When a scum moving device 5 is provided in a conduit 1 that is longer in the moving direction, three or more scum moving devices 5 can be provided at intervals in the moving direction.

[0044] Next, a scum moving device 5 according to a third embodiment will be described.

[0045] FIG. 7 is a plan view similar to FIG. 1 of a water conduit equipped with a scum moving device of the third embodiment.

[0046] The scum moving device 5 of the third embodiment shown in FIG. 7 differs from the scum moving device 5 shown in FIG. 1 in that two scum moving devices 5 are provided spaced apart in the moving direction, the shape of a hollow body 51, the shape of a nozzle 52, and the provision of a gas supply device 7. Another difference is that the height positions at which the hollow body 51 and the nozzle 52 are arranged are lower than those of the scum moving device 5 shown in FIG. 1. As shown in FIG. 7, two scum moving devices 5 of the third embodiment are arranged in the conduit 1 spaced apart in the moving direction. The scum moving device 5 arranged on the upstream side and the scum moving device 5 arranged on the downstream side have the same shape. Hereinafter, the scum moving device 5 arranged on the downstream side may be omitted from the description that overlaps with the scum moving device 5 arranged on the upstream side.

[0047] The hollow body 51 of the scum moving device 5, located upstream, extends from near the upstream wall 13 along the moving direction. The hollow body 51 is composed of a single pipe with an inner diameter of 150 mm and a length of 2 m. The upstream end 51u and downstream end 51d of the hollow body 51 are open. The sides of the hollow body 51 are formed with a second right opening 51R on the right side of the hollow body 51 when viewed from the upstream side, and a second left opening 51L on the left side. The second right opening 51R, the left side, and the second left opening 51L are located at the same positions in the moving direction and the height direction. These second right opening 51R and second left opening 51L are examples of openings. While the second right opening 51R and the second left opening 51L are preferably located in the same positions in the moving direction, they do not need to be completely aligned; they may be located in a partially overlapping position. The second right opening 51R and the second left opening 51L will be described in detail later. The length along the movement direction of the hollow body 51 of the scum moving device 5 arranged on the upstream side is shorter than the distance between the hollow body 51 of the scum moving device 5 arranged on the upstream side and the hollow body 51 of the scum moving device 5 arranged on the downstream side. The distance between the upstream end 51u of the hollow body 51 of the scum moving device 5 arranged on the upstream side and the upstream end 51u of the hollow body 51 of the scum moving device 5 arranged on the downstream side is 10 m. Therefore, the distance between the hollow body 51 of the scum moving device 5 arranged on the upstream side and the hollow body 51 of the scum moving device 5 arranged on the downstream side is 8 m. In addition, the distance between the upstream end 51u of the hollow body 51 of the scum moving device 5 arranged on the downstream side and the scum intake port 331 of the scum removing device 3 is also 10 m. Note that in Figures 7 and 8, the distance between the hollow body 51 of the scum moving device 5 arranged on the upstream side and the hollow body 51 of the scum moving device 5 arranged on the downstream side is shown slightly shorter. The distance between the hollow body 51 of the scum moving device 5 arranged downstream and the scum intake port 331 of the scum removing device 3 is also shown slightly shorter.

[0048] FIG. 8 is an FF cross-sectional view of the water conduit shown in FIG.

[0049] As shown in Figure 8, the hollow body 51 of the scum moving device 5 located upstream is fixed to a predetermined position in the conduit 1 by a support member 161 suspended from the ceiling 16 of the conduit 1. The lower end of the support member 161 is fixed to the center of the hollow body 51 in the direction of movement. When the water level in the conduit 1 is at the high water level (HWL) or the standard water level (SWL), the hollow body 51 is submerged, with the entire second right opening 51R and the entire second left opening 51L (see Figure 7). When the water level in the conduit 1 is at the high water level (HWL), the axis 51c of the hollow body 51 (see Figure 9(b)) is located 400 mm below the water surface. On the other hand, when the water level in the conduit 1 is at the low water level (LWL), the hollow body 51 is fully exposed, with the entire second right opening 51R and the entire second left opening 51L exposed to the atmosphere. At the low water level (LWL), the axis 51c of the hollow body 51 is located 100 mm above the water surface. Therefore, at a water level between the low water level (LWL) and the standard water level (SWL), the lower sides of the second right opening 51R and the second left opening 51L of the hollow body 51 are located below the water surface, and the upper side is semi-exposed to the atmosphere.

[0050] The upstream end of the nozzle pipe 53 of the scum moving device 5 arranged upstream in the sewage supply direction and the upstream end of the nozzle pipe 53 of the scum moving device 5 arranged downstream in the sewage supply direction are connected to a single sewage supply pipe 54. Sewage pumped up from the settling tank 9 is supplied to the sewage supply pipe 54. However, the discharged sewage may be pumped up from a source other than the settling tank 9. Furthermore, water from another pond, a tap, or the like may be used instead of sewage. A flow control valve 531 and an electric valve 532 are installed on the nozzle pipe 53. When the electric valve 532 is opened, sewage at a flow rate adjusted by the flow control valve 531 passes through the electric valve 532 and is supplied to the nozzle 52.

[0051] Figure 9(a) is an enlarged view of part G in Figure 8, and Figure 9(b) is a cross-sectional view taken along line HH of Figure 9(a). Figure 9(a) does not show the components that make up the water conduit 1. Figure 9(b) also does not show the background and hatching that indicates the cross section other than the discharge port 521 and the supply port 71.

[0052] As shown in FIG. 9(b), the hollow body 51 has a circular cross-sectional shape with a second right opening 51R on its right side (left side in FIG. 9(b)) and a second left opening 51L on its left side (right side in FIG. 9(b)). An internal space S is formed by the hollow body 51. The internal space S is defined by the inner peripheral surface 51a of the hollow body 51. Therefore, the internal space S is closed at the top and bottom ends and open at the left and right ends. The opening heights of the second right opening 51R and the second left opening 51L are 40 mm. The center heights of the second right opening 51R and the second left opening 51L are the same as the height of the axis 51c of the hollow body 51. In other words, the second right opening 51R and the second left opening 51L are located directly to the left and right of the hollow body 51, respectively. The second right opening 51R and the second left opening 51L are preferably positioned at the same height in the vertical direction, but they do not have to be completely aligned. Additionally, the center height of the second right opening 51R and the second left opening 51L may be higher than the height of the axial center 51c of the hollow body 51, or may be lower than the height of the axial center 51c of the hollow body 51. The second right opening 51R and the second left opening 51L are rectangular openings when viewed from the side of the hollow body 51, and their length in the direction of movement is longer than their length in the height direction. The second right opening 51R and the second left opening 51L extend along the direction of movement from 350 mm downstream from the upstream end of the hollow body 51 to 50 mm upstream from the downstream end of the hollow body 51. In other words, the second right opening 51R and the second left opening 51L extend 1600 mm along the direction of movement. These second right opening 51R and second left opening 51L act as outlets for discharging wastewater discharged from the discharge port 521 into the internal space S to the outside of the internal space S. The second right opening 51R and the second left opening 51L may be formed on the entire side surface of the hollow body 51. However, in this case, the hollow body 51 would be divided into two, and an additional support member 161 would be required to support the lower hollow body 51. Therefore, it is preferable to have a portion where the second right opening 51R or the second left opening 51L is not formed. Furthermore, extending the second right opening 51R and the second left opening 51L to one of the downstream and upstream ends of the hollow body 51 would reduce the strength of the hollow body 51. Therefore, it is preferable to provide portions at both ends where the second right opening 51R and the second left opening 51L are not formed.

[0053] As shown in FIG. 9(a), the tip of the nozzle 52 extends from the upstream end 51u of the hollow body 51 into the internal space S formed by the hollow body 51. The tip of the nozzle 52 has an elongated hole shape formed by flattening a pipe with an inner diameter of 80 mm from both sides. The tip of the nozzle 52 is formed with a discharge port 521 having a flat shape that is expanded in the height direction while being flattened in the direction toward the side of the hollow body 51 (width direction). The maximum height of the discharge port 521 is 117 mm, and the maximum opening length of the discharge port 521 in the width direction is 18 mm. The discharge port 521 is located upstream of the upstream ends of the second right opening 51R and the second left opening 51L and downstream of the upstream end 51u of the hollow body 51. As described above, the discharge port 521 may be located upstream of the upstream end 51u of the hollow body 51 or at the same position as the upstream end 51u, as long as it can discharge wastewater into the internal space S. That is, the discharge port 521 only needs to be located at the upstream end 51u of the hollow body 51. The discharge port 521 may also be located downstream of the upstream ends of the second right opening 51R and the second left opening 51L. However, in this location, wastewater is not discharged from the upstream ends of the second right opening 51R and the second left opening 51L, which are located upstream of the discharge port 521. Conversely, the ejector effect may result in wastewater outside the internal space S being sucked in through the second right opening 51R and the second left opening 51L. The wastewater supplied to the nozzle 52 from the nozzle piping 53 is discharged from the discharge port 521 in the direction of movement. The wastewater discharged from the discharge port 521 forms a water flow in the internal space S at a speed corresponding to the discharge flow rate, and is discharged to the outside of the internal space S through the downstream end 51d of the hollow body 51, the second right opening 51R, or the second left opening 51L. In the third embodiment, the discharge port 521 has a flattened shape that is flattened in the width direction and expanded in the height direction, thereby increasing the discharge pressure of the wastewater discharged from the discharge port 521 and preventing the discharged wastewater from spreading out toward the sides. This prevents the wastewater discharged from the discharge port 521 from being suddenly discharged to the outside of the internal space S through the second right opening 51R or the second left opening 51L, making it easier to maintain the amount of wastewater discharged from the second right opening 51R or the second left opening 51L downstream in the direction of movement. In addition, a certain amount of wastewater can be discharged from the downstream end 51d of the hollow body 51.By discharging wastewater from the entire second right opening 51R or the entire second left opening 51L, the bridge can be destroyed over a long range along the direction of movement, and the scum can be released from the state of being suspended between the side walls.

[0054] The gas supply device 7 is composed of a pipe extending from the atmosphere above the water conduit 1 to the hollow body 51. The leading and trailing ends of the pipe constituting the gas supply device 7 are open. The gas supply device 7 is fixed to the nozzle piping 53 by a fixture (not shown). The leading end of the gas supply device 7 enters the internal space S from the upstream end 51u of the hollow body 51. A supply port 71 for supplying gas is formed at the leading end of the gas supply device 7. The supply port 71 is disposed near the discharge port 521. As shown in FIG. 9(b), in this third embodiment, the supply port 71 is disposed near the lower end of the discharge port 521, at a position where it partially overlaps with the discharge port 521 in the height direction. When wastewater is discharged from the discharge port 521 toward the internal space S, air is drawn in from the gas supply device 7 due to the ejector effect and supplied into the internal space S together with the wastewater. The supplied gas moves in the movement direction while mixing with the wastewater discharged from the discharge port 521, and is released to the outside of the internal space S from the downstream end 51d of the hollow body 51, the second right opening 51R, or the second left opening 51L. In this third embodiment, the gas can be supplied by simply using a tubular or hose-shaped gas supply device 7, so the scum moving device 5 can be constructed inexpensively. Note that if it is desired to increase the amount of air supplied, a pump for sending air may be provided at the rear end of the gas supply device 7.

[0055] Alternatively, a fine bubble water supply device for supplying fine bubble water may be provided instead of or in addition to the gas supply device 7. In this case, the fine bubble water supply port is preferably located near the discharge port 521. When wastewater is discharged from the nozzle 52, fine bubble water is drawn in by the ejector effect, allowing fine bubble water to be easily supplied into the internal space S without a supply pump. However, fine bubble water may also be stored in a water tank placed above ground and supplied by head pressure, or it may be supplied using a pump. Note that fine bubble water is a liquid containing fine bubbles of 100 μm or less. Fine bubble water may be a liquid containing microbubbles, which are bubbles with a diameter of more than 1 μm and 100 μm or less, or may be a liquid containing ultrafine bubbles, which are bubbles with a diameter of 1 μm or less. Furthermore, fine bubble water may be a liquid containing both microbubbles and ultrafine bubbles. Supplying fine bubble water can clean and move the wastewater in the water conduit 1.

[0056] Fig. 10 is a plan view showing the operation of the scum moving device of the third embodiment. Fig. 10 mainly shows the operation of the scum moving device 5 located downstream. The wastewater supply pipe 54, the inlet 121 to the settling tank, and the inlet door 122 are not shown.

[0057] First, at a predetermined time when scum in the conduit 1 is to be removed from the conduit 1, the gate 34 is lowered to a position corresponding to the water level in the conduit 1. This causes a flow of wastewater from the scum intake port 331 toward the scum pit 31 near the water surface, and the scum in the peripheral region N3 of the scum intake port 331 flows into the scum pit 31. In Figure 10, the peripheral region N3 where the scum has been removed from the water surface by flowing into the scum pit 31 is shown by hatching drawn with lines pointing downward to the left. This process of lowering the gate 34 to allow the scum in the peripheral region N3 to flow into the scum pit 31 corresponds to an example of an inflow process.

[0058] Next, the motor-operated valve 532 of the scum moving device 5 arranged downstream is opened, and the wastewater is discharged in the movement direction from the discharge port 521 of the scum moving device 5 arranged downstream. The discharged wastewater generates a fluid flow in the movement direction within the internal space S (see FIG. 9(b)). The wastewater discharged from the discharge port 521 into the internal space S is released from the second right opening 51R and the second left opening 51L, and the downstream end 51d of the hollow body 51. This process of discharging the wastewater from the discharge port 521 of the scum moving device 5 arranged downstream and releasing it from the hollow body 51 corresponds to an example of a downstream discharge process. If a bridge is formed between the left wall 11 and the right wall 12 of the water conduit 1 due to scum spanning the gap, the bridge is destroyed by the wastewater discharged from the second right opening 51R and the second left opening 51L, and the downstream end 51d of the hollow body 51. In addition, the scum that made up the destroyed bridge moves in the direction of movement due to the water current that occurs near the water surface of the water conduit 1. The state in which the bridge is destroyed and the scum moves will be explained for each water level.

[0059] When the water level in the water conduit 1 is at the low water level (LWL) shown in FIG. 8 , the hollow body 51 is fully exposed, with the entire second right opening 51R and the entire second left opening 51L exposed to the atmosphere. At the low water level (LWL), the downstream end 51d of the hollow body 51 is also fully exposed to the atmosphere. As indicated by the solid arrows pointing diagonally downward to the right in FIG. 10 , a portion of the wastewater discharged into the internal space S is discharged from the second right opening 51R at an angle slightly tilted to the right with respect to the direction of movement, and then falls toward the water surface while flying through the atmosphere. The wastewater then falls into the fourth vicinity area N4, which is the right vicinity area of ​​the hollow body 51. As indicated by the solid arrows pointing diagonally upward to the right in FIG. 10 , another portion of the wastewater discharged into the internal space S is discharged from the second left opening 51L at an angle slightly tilted to the left with respect to the direction of movement, and then falls toward the water surface while flying through the atmosphere. The sewage then falls into a fifth vicinity region N5, which is the left vicinity region of the hollow body 51. Furthermore, as indicated by the two solid arrows pointing rightward in FIG. 10 , the sewage discharged into the internal space S that is not discharged from the left-second-right opening 51R and the second-left opening 51L is discharged in the direction of movement from the downstream end 51d of the hollow body 51. The sewage then falls into a downstream vicinity region N6, which is the downstream vicinity region of the hollow body 51. As a result, the scum that formed bridges in the fourth vicinity region N4, the fifth vicinity region N5, and the downstream vicinity region N6 collapses, destroying the bridges in those regions. The fourth vicinity region N4 and the fifth vicinity region N5 are elongated regions that extend along the lengths of the left-second-right opening 51R and the second-left opening 51L in the direction of movement, and are indicated by cross-hatching in FIG. 10 . The downstream vicinity region N6 is a long hole-shaped region having a length according to the force of the wastewater discharged from the downstream end 51d, and is indicated in FIG. 10 by hatching drawn with lines pointing downward to the right.

[0060] The scum that formed bridges in the fourth vicinity region N4, the fifth vicinity region N5, and the downstream vicinity region N6 becomes floating scum on the water surface. Island-like scum forms in the region between the fourth vicinity region N4 and the fifth vicinity region N5. Furthermore, as the discharged wastewater reaches the water surface, a water current and waves are formed near the water surface in the direction of movement. The floating scum and island-like scum move in the direction of movement due to the formed water current. As a result, the bridges downstream of the fourth vicinity region N4, the fifth vicinity region N5, and the downstream vicinity region N6 are pushed in the direction of movement toward the scum-free peripheral region N3, where they flow into the scum intake port 331 and into the scum pit 31. Furthermore, the resulting waves gradually destroy the remaining bridges that formed bridges around the fourth vicinity region N4, the fifth vicinity region N5, and the downstream vicinity region N6, and they are carried along by the water current in the direction of movement. By leaving the electric valve 532 open for a predetermined time, these actions can move most of the scum downstream of the vicinity of the upstream ends of the second right opening 51R and the second left opening 51L of the hollow body 51 to the scum pit 31.

[0061] When the water level in the conduit 1 is at the standard water level SWL or the high water level HWL shown in Figure 8, the hollow body 51 is submerged, with the entire left second right opening 51R and the entire second left opening 51L located below the water surface. At the standard water level SWL or the high water level HWL, the downstream end 51d of the hollow body 51 is also submerged, with the entire downstream end 51d located below the water surface. When submerged, the sewage discharged from the outlet 521 into the internal space S generates an ejector effect, and the sewage outside the internal space S is sucked into the internal space S from the upstream end 51U of the hollow body 51. In Figure 10, the broken arrows indicate the sewage being sucked into the internal space S due to the ejector effect. The sewage sucked into the internal space S and the sewage discharged from the outlet 521 into the internal space S are released from the left second right opening 51R, the second left opening 51L, and the downstream end 51d of the hollow body 51. The sewage released into the water from the second right opening 51R, the second left opening 51L, and the downstream end 51d of the hollow body 51 creates a water current within the water conduit 1, generating waves near the water surface. As described above, the expected water level fluctuation is 500 mm, so even when the first right opening 511R is submerged, it will not be significantly separated from the water surface. Furthermore, air is supplied from the supply port 71 of the gas supply device 7 and mixes with the sewage flowing in the internal space S. Therefore, the mixed air causes the sewage released from the hollow body 51 to rise toward the water surface. Furthermore, the water current generated by the sewage released from the hollow body 51 is stronger than the water current generated when the hollow body 51 is fully exposed, as described above. Furthermore, higher waves are formed compared to when the hollow body 51 is fully exposed. This strong water current, accompanied by high waves, collides with the bridge, destroying it. The water flow accompanied by waves generated by the sewage released from the second right opening 51R moves from the second right opening 51R at an angle slightly inclined to the right with respect to the direction of movement. This water flow destroys the bridge in the fourth vicinity area N4. Meanwhile, the water flow accompanied by waves generated by the sewage released from the second left opening 51L moves from the second left opening 51L at an angle slightly inclined to the left with respect to the direction of movement. This water flow destroys the bridge in the fifth vicinity area N5.Furthermore, the water flow accompanied by waves generated by the wastewater discharged from the downstream end 51d of the hollow body 51 advances in the direction of movement, destroying the bridge in the downstream vicinity region N6.

[0062] As in the fully exposed state, floating scum and islands of scum form, and these scum move in the direction of movement due to the resulting water flow. As a result, bridges downstream of the fourth vicinity region N4, the fifth vicinity region N5, and the downstream vicinity region N6 are pushed in the direction of movement toward the scum-free peripheral region N3, where they flow into the scum pit 31 through the scum inlet 331. Furthermore, the resulting waves gradually destroy the remaining bridges around the fourth vicinity region N4, the fifth vicinity region N5, and the downstream vicinity region N6, and they move in the direction of movement due to the water flow. Additionally, at the upstream end 51u of the hollow body 51, the ejector effect sucks in nearby sewage, destroying the bridges near the upstream end 51u. Note that, depending on the relative positions of the second right opening 51R and the second left opening 51L of the hollow body 51 and the discharge port 521, the ejector effect may cause nearby sewage to be sucked in near the upstream ends of the second right opening 51R and the second left opening 51L. By leaving the motor-operated valve 532 open for a predetermined time, these actions can move most of the scum downstream of the vicinity of the upstream end 51u of the hollow body 51 to the scum pit 31.

[0063] When the water level in the conduit 1 is between the low water level (LWL) and the standard water level (SWL), the hollow body 51 may be in a semi-exposed state, with the left second right opening 51R, the second left opening 51L, and the lower sides of the downstream end 51d of the hollow body 51 below the water surface, leaving the upper side exposed to the atmosphere. In this semi-exposed state, sewage is discharged from the left second right opening 51R, the second left opening 51L, and the upper and lower sides of the downstream end 51d of the hollow body 51. The sewage discharged into the atmosphere from the left second right opening 51R, the second left opening 51L, and the upper side of the downstream end 51d of the hollow body 51 produces the same effects as in the fully exposed state. Furthermore, the sewage discharged into the water from the left second right opening 51R, the second left opening 51L, and the lower side of the downstream end 51d of the hollow body 51 produces the same effects as in the fully exposed state. By acting on these, the bridge can be destroyed in the same way as in the submerged state and the fully exposed state, and the scum floating on the water surface can be moved to the scum removal device 3.

[0064] After closing the motor-operated valve 532 of the scum moving device 5 arranged downstream, the motor-operated valve 532 of the scum moving device 5 arranged upstream is opened to discharge wastewater from the discharge port 521 of the scum moving device 5 arranged upstream in the direction of movement. This process of discharging wastewater from the discharge port 521 of the scum moving device 5 arranged upstream and releasing it from the hollow body 51 corresponds to an example of an upstream discharge process. This allows scum located near the upstream end 51u of the hollow body 51 of the scum moving device 5 arranged upstream or downstream of the upstream ends of the second right opening 51R and the second left opening 51L to be moved, similar to the case where wastewater is discharged in the direction of movement from the discharge port 521 of the scum moving device 5 arranged downstream as described above. The moved scum floats on the water surface at a position overlapping the hollow body 51 of the scum moving device 5 arranged downstream in the direction of movement, or on the water surface downstream of the scum moving device 5 arranged downstream.

[0065] After closing the motor-operated valve 532 of the scum moving device 5 located upstream, the motor-operated valve 532 of the scum moving device 5 located downstream is opened again to discharge wastewater in the moving direction from the discharge port 521 of the scum moving device 5 located downstream. This allows scum floating on the water surface at a position overlapping the hollow body 51 of the scum moving device 5 located downstream in the moving direction or on the water surface downstream of the scum moving device 5 located downstream to be moved to the scum pit 31. After a predetermined time required for the scum to move to the scum pit 31 has elapsed, the gate 34 is raised to close the scum intake port 331, and the motor-operated valve 532 of the scum moving device 5 located downstream is also closed. Then, the scum pump 32 is driven for a predetermined time to discharge the scum to the outside, completing the process. Note that the motor-operated valve 532 of the scum moving device 5 located upstream and the motor-operated valve 532 of the scum moving device 5 located downstream may be opened simultaneously. In other words, the downstream discharge process and the upstream discharge process may be performed simultaneously. Also, the motor-operated valve 532 of the scum moving device 5 arranged downstream may be opened at the same time as the gate 34 is lowered to a position according to the water level in the water conduit 1. In other words, the inflow process and the downstream discharge process may be performed simultaneously, or the inflow process, downstream discharge process, and upstream discharge process may be performed simultaneously.

[0066] According to this third embodiment, a water flow accompanied by waves can be generated to break the bridge formed in the conduit 1 and move the scum in the movement direction. The water flow then moves the scum to the scum removal device 3, thereby removing the scum from the conduit 1. Three or more scum moving devices 5 of this third embodiment may be installed side by side at intervals in the movement direction of the conduit 1.

[0067] 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 this embodiment, the scum moving device 5 is disposed in the conduit 1, but the scum moving device 5 may also be disposed in the settling tank 9. Furthermore, the scum moving device 5 may also be disposed in other equipment in the wastewater treatment facility as long as scum is generated on the water surface. Furthermore, while the hollow body 51 has an arc-shaped cross section, it may also have a polygonal cross section as long as it has openings on its side. Furthermore, while the hollow body 51 is fixed at a height that changes state to the fully exposed state, it may also be fixed at a height that changes state only to the partially exposed state or the submerged state. Furthermore, although the example in which the hollow body 51 is disposed in the center of the conduit 1 in the width direction has been described, the hollow body 51 may also be disposed at one end of the conduit 1 in the width direction. When disposed at one end of the width direction, it is preferable to provide an opening only on the side of the other end.

[0068] According to the scum moving device 5 of each embodiment described above, even if a bridge is formed, it is possible to move the scum to the scum removal device 3. Note that although the scum moving device targeted at scum has been described here, the same effect as this embodiment can be achieved even if it is targeted at floating matter other than viscous scum.

[0069] Note that even if a component is included only in the description of each of the above-described embodiments, that component may be applied to other embodiments.

[0070] The scum moving device described above is a scum moving device that moves scum floating on the water surface in a predetermined moving direction, a hollow body extending along the movement direction; a discharge port for discharging a fluid into an internal space defined by an inner circumferential surface of the hollow body, the hollow body is cylindrical, and an opening extending along the movement direction is formed in a side portion of the hollow body at a height that coincides with the axis of the hollow body; The discharge port may be disposed in the internal space at an upstream end of the hollow body, and may discharge the fluid in the axial direction of the hollow body.

[0071] Also, a scum moving device that moves scum floating on the water surface in a predetermined moving direction, a hollow body extending along the movement direction; a discharge port for discharging a fluid into an internal space defined by an inner circumferential surface of the hollow body, The hollow body may have an opening formed in a side portion thereof, the opening extending along the movement direction.

[0072] The scum moving device may be provided with a supply port for supplying gas to the internal space.

[0073] In this scum moving device, the discharge port may have a flat shape that is collapsed in a direction toward the side and widens in a height direction.

[0074] The scum moving device described above is a scum moving device that moves scum floating on the water surface in a predetermined moving direction, a hollow body extending along the movement direction; a discharge port for discharging a fluid into an internal space defined by an inner circumferential surface of the hollow body, the hollow body has an opening formed in a side portion thereof, the opening extending along the movement direction, the opening acts as a discharge port for discharging the fluid discharged from the discharge port into the internal space to the outside of the internal space, The discharge port may be disposed in the internal space at an upstream end of the hollow body, and may discharge the fluid in the axial direction of the hollow body.

[0075] Here, the discharge port may be one that discharges fluid in the movement direction. The discharge port may also be located at the upstream end of the hollow body in the movement direction. Additionally, the internal space may be a space whose upper and lower ends are closed. The internal space may also be a space whose upstream and downstream ends in the movement direction are open.

[0076] This scum moving device can move the scum a long distance along the moving direction.

[0077] In this scum moving device, the hollow body may be fixed and change state depending on fluctuations in the water level between an exposed state in which at least a portion of the opening is exposed to the atmosphere and a submerged state in which the entire opening is located below the water surface.

[0078] The exposed state may be a fully exposed state in which the entire opening is exposed to the atmosphere. Also, the discharge port may discharge a mixed fluid in which a liquid and a gas are mixed.

[0079] The water level in a conduit or the like is not constant but fluctuates. If the hollow body is placed in a position that is constantly exposed to the atmosphere, when the water level drops, the opening is far removed from the water surface in the vertical direction, causing the momentum of the released fluid toward the scum removal device to weaken before it reaches the water surface. Even if the weakened fluid reaches the water surface, it cannot form a strong water flow, thereby weakening its effect of moving scum in the direction of movement. In contrast, by placing the hollow body in a position that changes state between the exposed state and the submerged state, the opening is not far removed from the water surface in the vertical direction in the exposed state, allowing the fluid released from the opening to reach the water surface while retaining its momentum. Furthermore, in the submerged state, the fluid released from the opening into the water can generate a strong water flow accompanied by waves. This strong water flow accompanied by waves can destroy the bridge and move scum downstream in the direction of movement.

[0080] Furthermore, because the fluctuation range of the water level is limited to a certain range, even if the exposed state is a fully exposed state in which the entire opening is exposed to the atmosphere, the opening does not move significantly away from the water surface in the vertical direction in the fully exposed state. Therefore, the released fluid reaches the water surface before its momentum significantly weakens, thereby forming a strong water current. Furthermore, if the outlet discharges the mixed fluid, the mixed fluid released from the opening in the submerged state is likely to rise toward the water surface due to the gas contained in the mixed fluid. Therefore, by discharging the mixed fluid, a stronger water current and higher waves can be generated on the water surface in the submerged state.

[0081] In addition, in this scum moving device, the opening comprises a right opening formed on the right side of the hollow body when viewed from the upstream side in the moving direction and a left opening formed on the left side of the hollow body, The right opening and the left opening may be arranged alternately along the movement direction.

[0082] Since the fluid can be discharged from both the left and right sides of the hollow body, scum can be moved even in a wide water conduit or the like.

[0083] In this scum moving device, the opening comprises a right opening formed on the right side of the hollow body when viewed from the upstream side in the moving direction and a left opening formed on the left side of the hollow body, The right opening and the left opening may be arranged at positions overlapping each other in the movement direction.

[0084] The fluid discharged from both the left and right sides of the hollow body forms islands of scum that are released from both the left and right side walls and are easily movable. These islands of scum are then moved by the water flow, making it easier to move scum downstream in the direction of movement. In addition, scum can be moved even in wide conduits.

[0085] In this scum moving device, a supply port for supplying gas to the internal space may be provided separately from the discharge port.

[0086] When the entire opening is submerged, the fluid discharged from the outlet and the gas supplied from the supply port mix in the internal space, and the gas causes the fluid discharged from the opening to rise toward the water surface. Therefore, even if the hollow body is submerged to a certain depth, it can generate strong water currents and high waves on the water surface.

[0087] In this scum moving device, the discharge port may have a flat shape that is collapsed in the width direction and widens in the height direction.

[0088] This shape prevents the discharged wastewater from spreading too far to the sides immediately after discharge, making it easier to maintain the amount of fluid flowing out of the opening downstream in the direction of movement, thereby freeing scum from being stretched across the side walls over a long range along the direction of movement.

[0089] In addition, in this scum moving device, the hollow bodies are provided in plurality at intervals in the moving direction, The discharge port may be disposed at an upstream end portion of each of the hollow bodies in the direction of movement.

[0090] In this way, the scum can be moved a long distance in the movement direction, and therefore it is possible to deal with a water conduit or the like that is long in the movement direction.

[0091] In this scum moving device, the length of the hollow body along the moving direction may be shorter than the interval.

[0092] According to this aspect, the hollow body can be easily manufactured, and the scum moving device can be constructed inexpensively. [Explanation of symbols]

[0093] 5. Sukamu mobile device 51 Hollow Body 51a Inner circumference 51R 2nd right opening 51L 2nd left opening 511R 1st right opening 512L 1st left opening 521 Spit Out S Interior Space

Claims

1. A scum moving device that moves scum floating on the water surface in a predetermined moving direction, a hollow body extending along the movement direction; a discharge port for discharging a fluid into an internal space defined by an inner circumferential surface of the hollow body, the hollow body has an opening formed in a side portion thereof, the opening extending along the movement direction, the opening acts as a discharge port for discharging the fluid discharged from the discharge port into the internal space to the outside of the internal space, A scum moving device characterized in that the discharge outlet is located within the internal space at the upstream end of the hollow body, discharges the fluid toward the axial direction of the hollow body, and has a flattened, elongated hole shape.

2. 2. The scum moving device according to claim 1, wherein the discharge port has an elongated hole shape that is collapsed in the height direction and widens in the width direction.

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