Water diversion device, sewage system, and water intake system

Abstract

In water diversion devices, if sizes of respective adjustment tanks are designed to be small, a jet flow of sewage that has passed through an orifice hole potentially affects water surface fluctuation. In this water diversion device, energy carried by a jet flow of passing sewage is dispersed since a third orifice hole (24A) and a second orifice hole (24B) are configured by being divided into two. In addition, since the third orifice hole (24A) and the second orifice hole (24B) are formed so as to be shifted oppositely in a direction orthogonal to a flow path direction, a jet flow of sewage that has passed through the third orifice hole (24A), which is positioned upstream of the second orifice hole (24B), is attenuated and passes through the second orifice hole (24B), which is positioned downstream of the third orifice hole (24A).

Description

Water distribution equipment, sewage system, and water intake system

[0001] This disclosure relates to water distribution equipment, sewerage systems, and water intake systems.

[0002] In a combined sewer system, rainwater from rainfall and wastewater such as domestic sewage are carried in the same pipeline, during rainfall, rainwater and wastewater (hereinafter, "rainwater and wastewater" will also be referred to as "sewage") are allowed to flow into the combined sewer pipe. In this combined sewer system, if more than a certain amount of rainwater flows into the combined sewer pipe, it is necessary to divide the sewage in a water distribution device into sewage that flows to the sewage treatment plant via a collection pipe and sewage that is discharged into rivers, etc., via a discharge pipe. For example, Patent Document 1 discloses a device as such a water distribution device having a plurality of adjustment tanks, partition walls provided between each adjustment tank, orifice holes formed in each partition wall, and overflow weirs provided on both sides of the bottom of each adjustment tank facing each other and along the direction of the flow path. In this water distribution system, sewage flowing in from the combined sewer pipe is sequentially passed through each adjustment tank and each orifice hole and then distributed to the collection pipe in a predetermined amount, while sewage is distributed to the discharge pipe by overflowing from each overflow weir.

[0003] Patent No. 6672507

[0004] In some cases, the adjustment tanks of the aforementioned water distribution system may have to be fixed in a narrow space, for example, due to limited workspace or difficulty in securing space from adjacent structures.

[0005] However, this water distribution device had a problem: because each partition wall had only one orifice hole, designing each adjustment tank to be small could cause the sewage jets coming out of the orifice holes to affect the water level fluctuations.

[0006] This disclosure is made in view of the above circumstances and aims to provide a water distribution device that can be miniaturized, and a sewage system and water intake system having a water distribution device that can be miniaturized.

[0007] To achieve the above objective, a water distribution device according to the first aspect of this disclosure is a water distribution device that connects an inlet pipe into which flowing water flows, a collection pipe, and a discharge pipe, and divides the flowing water flowing in from the inlet pipe into flowing water to flow to the collection pipe and flowing water to flow to the discharge pipe, comprising: a flow path through which the flowing water flowing in from the inlet pipe flows out to the collection pipe; a plurality of overflow weirs erected on at least one of both sides of the flow path; a plurality of partition wall sections provided between the plurality of overflow weirs and between the overflow weirs and the collection pipe, and having orifice holes formed therein; and a plurality of regulating tanks partitioned by the plurality of overflow weirs and the plurality of partition wall sections, wherein the discharge pipe into which the flowing water overflowing from the plurality of overflow weirs flows is connected below the plurality of regulating tanks, and the orifice holes formed in the partition wall sections provided between the plurality of overflow weirs are plurality.

[0008] To achieve the above objective, a sewerage system relating to the second aspect of this disclosure is a sewerage system in which a combined sewer into which sewage flows, a collection pipe that carries sewage to a sewage treatment plant, and a discharge pipe are connected, and the sewerage system has a water distribution device that divides the sewage flowing in from the combined sewer into sewage that flows to the collection pipe and sewage that flows to the discharge pipe, wherein the water distribution device has a flow path through which the sewage flowing in from the combined sewer flows out to the collection pipe, a plurality of overflow weirs erected on at least one of both sides of the flow path, a plurality of partition walls provided between the plurality of overflow weirs and between the overflow weirs and the collection pipe and having orifice holes formed therein, and a plurality of adjustment tanks partitioned by the plurality of overflow weirs and the plurality of partition walls, and the discharge pipe into which the sewage overflowing from the plurality of overflow weirs flows is connected below the plurality of adjustment tanks. The orifice holes formed in the partition wall between the multiple overflow weirs are characterized by being multiple in number.

[0009] To achieve the above objective, a water intake system according to the third aspect of this disclosure is a water intake system having an inlet pipe into which river water flows, a collection pipe, and a discharge pipe connected together, and having a water distribution device that divides the river water flowing in from the inlet pipe into river water that flows to the collection pipe and river water that flows to the discharge pipe, wherein the water distribution device has a flow path through which the river water flowing in from the inlet pipe flows out to the collection pipe, a plurality of overflow weirs erected on at least one of both sides of the flow path, a plurality of partition wall sections provided between the plurality of overflow weirs and between the overflow weirs and the collection pipe and having orifice holes formed therein, and a plurality of regulating tanks partitioned by the plurality of overflow weirs and the plurality of partition wall sections, wherein the discharge pipe into which the river water overflowing from the plurality of overflow weirs flows is connected below the plurality of regulating tanks, and the number of orifice holes formed in the partition wall sections provided between the plurality of overflow weirs is plurality.

[0010] According to this disclosure, it is possible to provide a water distribution device that can be miniaturized, and a sewage system and water intake system having a water distribution device that can be miniaturized.

[0011] This is a partial cross-sectional plan view showing the configuration of a water distribution device according to the first embodiment of this disclosure. This is a cross-sectional view taken along line B-B in Figure 1A. This is a cross-sectional view taken along line C-C in Figure 1A. This is a partial cross-sectional plan view showing the state in which sewage flows through the water distribution device according to the first embodiment of this disclosure. This is a cross-sectional view taken along line B-B in Figure 2A. This is a cross-sectional view taken along line C-C in Figure 2A. This is a block diagram showing the configuration of a sewerage system having a water distribution device according to the first embodiment of this disclosure. This is an explanatory diagram for explaining the arrangement of orifice holes in the water distribution device of Comparative Example 1. This is an explanatory diagram for explaining the arrangement of orifice holes in the water distribution device of Comparative Example 2. This is an explanatory diagram for explaining the arrangement of orifice holes in the water distribution device of an embodiment of this disclosure. This is an analytical diagram showing the flow condition of the water distribution device of Comparative Example 1 when the inflow is normal. This is an analytical diagram showing the flow condition of the water distribution device of Comparative Example 2 when the inflow is normal. This is an analytical diagram showing the flow condition of the water distribution device of an embodiment of this disclosure when the inflow is normal. This is an analytical diagram showing the flow condition of the water distribution device of Comparative Example 1 when the inflow is at the peak of heavy rainfall. This is an analytical diagram showing the flow conditions of the water distribution device of Comparative Example 2 when the inflow rate is at the peak of heavy rainfall. This is an analytical diagram showing the flow conditions of the water distribution device of the embodiment of this disclosure when the inflow rate is at the peak of heavy rainfall. This is a graph showing the time changes of the inflow rate, overflow rate, and collection rate of the water distribution device of Comparative Example 1. This is a graph showing the time changes of the inflow rate, overflow rate, and collection rate of the water distribution device of Comparative Example 2. This is a graph showing the time changes of the inflow rate, overflow rate, and collection rate of the water distribution device of the embodiment of this disclosure. This is an analytical diagram showing the longitudinal flow velocity of the water distribution device of Comparative Example 2 when the inflow rate is at the peak of heavy rainfall. This is a partial cross-sectional plan view showing the configuration of the water distribution device according to the second embodiment of this disclosure. This is a partial cross-sectional plan view showing the configuration of the water distribution device according to the third embodiment of this disclosure. This is a partial cross-sectional plan view showing the configuration of the water distribution device according to the fourth embodiment of this disclosure. This is a cross-sectional view showing the configuration of the water distribution device according to the fifth embodiment of this disclosure. This is a block diagram showing the configuration of a water intake system having the water distribution device of this disclosure.

[0012] The water distribution device according to the embodiment of this disclosure will be described below with reference to the drawings.

[0013] (First Embodiment) The water distribution device according to the first embodiment will be described with reference to Figures 1A to 1C, 2A to 2C, and 3. Figures 1A and 2A are partial cross-sectional plan views showing only the pipe in cross-section, with the lid of the water distribution device 2 removed. The water distribution device 2 of the first embodiment is used in a combined sewer system 1, for example, as shown in Figure 3. The combined sewer system 1 is a sewer system that carries rainwater from rainfall and wastewater such as domestic wastewater in the same pipe, a combined sewer pipe.

[0014] The combined sewer system 1 includes a water distribution device 2 and a sewage treatment plant 5. The combined sewer system 1 also includes a combined pipe (inlet pipe) 6 for receiving rainwater and wastewater (sewage) during rainfall and directing the incoming sewage to the water distribution device 2, a discharge pipe 7 for discharging one portion of the sewage distributed by the water distribution device 2 into a public water body W such as a river, a collection pipe (collection pipe) 8 for directing the other portion of the sewage distributed by the water distribution device 2 to the sewage treatment plant 5, and a sewage treatment plant discharge pipe 9 for discharging the purified sewage from the sewage treatment plant 5 into the public water body W. At the sewage treatment plant 5, for example, advanced treatment is performed, in which incoming sewage is subjected to sedimentation, biological treatment and disinfection before discharge, and simplified treatment is performed, in which sewage is subjected to sedimentation and disinfection before discharge.

[0015] The water distribution device 2 is a device capable of precisely dividing sewage flowing in from the combined sewer pipe 6 into a predetermined amount of sewage that flows to the sewage treatment plant 5 via the shielding pipe 8, and sewage that is discharged into the public water body W via the discharge pipe 7. As shown in Figures 1A to 1C and 2A to 2C, the water distribution device 2 is erected on a base plate 25 and has a housing 26 with a closed lid 26e, containing three tanks: a first adjustment tank 2C, a second adjustment tank 2B, and a third adjustment tank 2A. The third adjustment tank 2A ​​is located on the upstream side, the first adjustment tank 2C is located on the downstream side, and the second adjustment tank 2B is located between the third adjustment tank 2A ​​and the first adjustment tank 2C. The first to third adjustment tanks 2C, 2B, and 2A are provided in a continuous sequence.

[0016] A confluence pipe 6 is connected to the upstream side wall 26a of the housing 26, and sewage flows from the confluence pipe 6 into the third adjustment tank 2A. A collection pipe 8 is connected to the downstream side wall 26b of the housing 26, which is opposite to the upstream side wall 26a, and sewage flows from the first adjustment tank 2C into the collection pipe 8. In other words, a flow path 20 is formed through which sewage flowing in from the confluence pipe 6 flows out into the collection pipe 8. A discharge pipe 7 is connected below the collection pipe 8 on the downstream side wall 26b of the housing 26. The discharge pipe 7 is connected to the lower center of the side wall 26b and is located below the first to third adjustment tanks 2C, 2B, and 2A.

[0017] The first to third adjustment tanks 2C, 2B, and 2A are mounted on a base 27. The base 27 is installed between the side walls 26a and 26b of the housing 26. The upper surface of the base 27 is formed in a stepped shape that slopes downward from the upstream side to the downstream side, and constitutes the first to third bottoms 21C, 21B, and 21A of the first to third adjustment tanks 2C, 2B, and 2A. That is, the first to third bottoms 21C, 21B, and 21A are formed to be progressively lower from the upstream side to the downstream side. The third bottom 21A is formed to be longer in the flow direction than the second bottom 21B and the first bottom 21C. In addition, the planar first to third bottoms 21C, 21B, and 21A are formed with their longitudinal ends inclined inward so that the width in the short direction narrows from the upstream side to the downstream side. The longitudinal ends of the first to third bottoms 21C, 21B, and 21A are formed with an inward inclination because the diameter of the downstream collection pipe 8 is smaller than the diameter of the upstream confluence pipe 6, among other reasons.

[0018] A pair of third overflow weirs 22A are erected opposite each other on both sides of the third bottom 21A of the third regulating tank 2A, along the direction of the flow path. Similarly, a pair of second overflow weirs 22B are erected opposite each other on both sides of the second bottom 21B of the second regulating tank 2B, along the direction of the flow path. Furthermore, a pair of first overflow weirs 22C are erected opposite each other on both sides of the first bottom 21C of the first regulating tank 2C, along the direction of the flow path. Since the first to third overflow weirs 22C, 22B, and 22A are provided on both sides of the flow path 20, the sewage that overflows from the first to third overflow weirs 22C, 22B, and 22A flows down the flow path 20 from both sides.

[0019] The height of the third overflow weir 22A on the upstream side is set to match the water level at which the planned amount of sewage flows into the combined pipe 6. The planned amount of sewage is set as the maximum amount of sewage that can be treated at the sewage treatment plant 5. If the height of the third overflow weir 22A is set higher than the water level at which the planned amount of sewage flows into the combined pipe 6, a backwater effect will be induced in the combined pipe 6, resulting in a decrease in the flow capacity of the combined pipe 6 and the accumulation and sedimentation of pollutants within the combined pipe 6. Furthermore, the height of the first overflow weir 22C on the downstream side is set to be higher than the water level of sewage that overflows from the first to third overflow weirs 22C, 22B, and 22A and flows into the housing 26.

[0020] Between the third regulating tank 2A ​​and the second regulating tank 2B (between the third overflow weir 22A and the second overflow weir 22B), a plate-shaped third partition wall 23A is erected in a direction perpendicular to the flow direction. Also, between the second regulating tank 2B and the first regulating tank 2C (between the second overflow weir 22B and the first overflow weir 22C), a plate-shaped second partition wall 23B is erected in a direction perpendicular to the flow direction. Also, between the first regulating tank 2C and the collection pipe 8 (between the first overflow weir 22C and the collection pipe 8), a plate-shaped first partition wall 23C is erected in a direction perpendicular to the flow direction. As a result, the first to third adjustment tanks 2C, 2B, and 2A are partitioned by the first to third overflow weirs 22C, 22B, and 22A and the first to third partition walls 23C, 23B, and 23A.

[0021] The third partition section 23A and the second partition section 23B are installed extending between the side walls 26c and 26d of the housing 26. By installing the third partition section 23A and the second partition section 23B between the side walls 26c and 26d, sewage overflowing from the third overflow weir 22A and the second overflow weir 22B is prevented from falling into the first adjustment tank 2C and causing wave effects. The first partition section 23C is provided in contact with the downstream side wall 26b of the housing 26.

[0022] Two third orifice holes 24A and two second orifice holes 24B are formed in the adjacent third partition wall 23A and second partition wall 23B, respectively. The third orifice holes 24A and the second orifice holes 24B are formed side by side in a direction perpendicular to the flow direction (the width direction of the flow path). Furthermore, the third orifice hole 24A is formed offset in one direction (downward in Figures 1A and 2A) relative to the center of the flow path 20 in a direction perpendicular to the flow direction, and the second orifice holes 24B are formed offset in the other direction (upward in Figures 1A and 2A) relative to the center of the flow path 20 in a direction perpendicular to the flow direction. One first orifice hole 24C is formed in the first partition wall 23C.

[0023] Furthermore, a management and inspection section 29 is provided on the lid 26e of the housing 26. The management and inspection section 29 is provided with an inspection hole, allowing inspection of the inside of the housing 26 from the outside.

[0024] Here, we will explain the flow rate control of the water distribution device 2. When it rains heavily or during torrential downpours, the sewage that flows from the combined pipe 6 into the water distribution device 2 is divided as shown in Figure 2A into two parts: sewage that passes sequentially through the third adjustment tank 2A, two third orifice holes 24A, the second adjustment tank 2B, two second orifice holes 24B, the first adjustment tank 2C, and the first orifice 24C and flows to the collection pipe 8, with the amount of sewage being the planned collection amount; and sewage that overflows from the third to first overflow weirs 22A, 22B, and 22C and flows to the discharge pipe 7.

[0025] Conventionally, in water distribution devices, if the size of each adjustment tank is designed to be small, the jet of sewage passing through the orifice holes may affect the water level fluctuations. However, since the third orifice hole 24A and the second orifice hole 24B are divided into two parts, the energy of the sewage jet passing through them is dispersed. Furthermore, since the third orifice hole 24A and the second orifice hole 24B are formed offset in opposite directions relative to the center of the flow path 20 in a direction perpendicular to the flow path direction, the jet of sewage passing through the upstream third orifice hole 24A can be reduced in energy, allowing the sewage to pass through the downstream second orifice hole 24B.

[0026] In the water distribution device 2, even if the amount of sewage flowing in from the combined pipe 6 increases, as shown in Figure 2B, the incoming sewage is sequentially passed through the upstream third adjustment tank 2A, the two third orifice holes 24A, the second adjustment tank 2B, and the two second orifice holes 24B, thereby sequentially mitigating the rise in the water level in the adjustment tanks. This reduces the range of fluctuation in the water level in the first adjustment tank 2C, which is located downstream and is directly involved in the collection and distribution of sewage, and suppresses fluctuations in the amount of sewage distributed to the collection pipe 8.

[0027] In the third adjustment tank 2A, which is located upstream and has a long length in the direction of the flow path, the complex hydraulic phenomena caused by the sewage flowing in from the confluence pipe 6 are limited, and the incoming sewage is controlled to approximately the target water distribution flow rate. Subsequently, the sewage that has passed through the third adjustment tank 2A ​​is passed through the second adjustment tank 2B and the first adjustment tank 2C downstream in sequence, further improving the accuracy of water distribution control and adjusting to the target water distribution flow rate.

[0028] As the amount of sewage flowing into the water distribution device 2 from the confluence pipe 6 increases, the overflow depth of sewage overflowing from the third overflow weir 22A in the third adjustment tank 2A ​​increases rapidly, causing a sensitive reaction. In contrast, in the second adjustment tank 2B, the overflow depth of sewage overflowing from the second overflow weir 22B increases only slightly, and in the first adjustment tank 2C, the overflow depth of sewage overflowing from the first overflow weir 22C does not increase as much as the overflow depth overflowing from the second overflow weir 22B, resulting in a slower reaction.

[0029] The amount of sewage that is diverted by the water distribution device 2 and flows into the collection pipe 8, which is equal to the planned collection amount, is discharged to the sewage treatment plant 5, where it undergoes advanced treatment and simplified treatment. The sewage that has been purified at the sewage treatment plant 5 is discharged into the public water body W via the discharge pipe 9 for the sewage treatment plant. In addition, the sewage that is diverted by the water distribution device 2 and flows into the discharge pipe 7 is also discharged into the public water body W.

[0030] In this embodiment of the water distribution device, the third orifice hole 24A and the second orifice hole 24B are each composed of two orifice holes 24B, and are formed offset in opposite directions in a direction perpendicular to the flow direction. This reduces the influence of the sewage jets passing through on water level fluctuations. As a result, the water distribution device of this embodiment enables more precise water distribution control and can be miniaturized depending on the installation situation. Ultimately, this contributes to the rationalization and labor saving of sewage systems.

[0031] Furthermore, in the water distribution device of this embodiment, first to third overflow weirs 22C, 22B, and 22A are provided on both sides of the flow path 20, which increases the overall length of the weir, stabilizes the hydraulic phenomena, and makes it possible to reduce the size of the housing 26.

[0032] Furthermore, in the combined sewer system of this embodiment, even during heavy rain or downpours, the water distribution device 2 enables more precise water distribution control, allowing for the precise distribution and collection of the target planned amount of sewage. As a result, the combined sewer system of this embodiment can avoid problems such as the merging problem where the merging pipe becomes a merging pipe again to collect water, accidents in pipeline facilities due to excessive merging, and problems at sewage treatment plants such as the discharge of untreated sewage. In addition, the combined sewer system of this embodiment can use a water distribution device 2 that can be made smaller, thus improving its versatility.

[0033] (Examples) The present disclosure will be described below based on examples, but the present disclosure is not limited in any way by these examples.

[0034] Regarding the water separation device of the present disclosure, the accuracy of water separation control was verified using numerical fluid analysis. In the examples, Comparative Example 1, and Comparative Example 2, analyses were performed with the conditions of the orifice holes of the water separation device changed. The water separation device was assumed to be a device for practical use in a combined sewer system. The scale of the water separation device was based on past examples of sewer facilities, and the diameter of the combined pipe (inflow pipe) was set to 5 m, the diameter of the collection pipe was set to 2.2 m, the length of the inner space of the water separation device in the flow path direction was set to 12 m, and the width of the inner space of the water separation device was set to 10 m. In this design, the planned collection amount was set to 6 m ３ / s as the normal sewage inflow amount, and the inflow amount of sewage at the peak of heavy rain was assumed to be 67 m ３ / s as an external force.

[0035] Also, the section length of the combined pipe (inflow pipe) of the water separation device was set to 50 m (10 times the pipe diameter), an inflow boundary was set at the upstream end of the combined pipe (inflow pipe), and an unsteady flow rate waveform was given as the inflow boundary condition. Specifically, assuming a sudden heavy rain, a flow rate waveform that linearly increases in a short time (8 minutes) from the normal state where the inflow amount of sewage is the planned collection amount to the peak of heavy rain was given. Also, outflow boundaries were set in the collection pipe and the discharge pipe, and the designed water level value was given as the boundary condition at each outflow boundary.

[0036] The water separation device of the example is different from the water separation device of the first embodiment in that, as shown in FIGS. 4C, 5C, and 6C, it has four adjustment tanks from the first tank (the first adjustment tank) to the fourth tank (the fourth adjustment tank). However, for the rest, a simplified configuration of the water separation device of the first embodiment was adopted for numerical fluid analysis. In the water separation device of the example, as shown in FIG. 4C, two second to fourth orifice holes were arranged side by side in the direction perpendicular to the flow path direction (width direction) at the second to fourth partition portions on the downstream side of the second to fourth tanks. Also, the fourth orifice hole and the third orifice hole formed in adjacent partition portions were arranged offset in the reverse direction with respect to the center of the flow path in the direction perpendicular to the flow path direction, and the third orifice hole and the second orifice hole were also arranged offset in the reverse direction with respect to the center of the flow path in the direction perpendicular to the flow path direction. Note that the width of the second to fourth orifice holes of the water separation device of the example is half the width of the orifice holes of Comparative Example 1 and Comparative Example 2 described later.

[0037] In the water separation device of Comparative Example 1, as shown in FIG. 4A, one first to fourth orifice holes were respectively provided in the first to fourth partition walls on the downstream side of the first to fourth tanks. Further, the second orifice hole and the third orifice hole were arranged with a shift of half the width of the orifice hole in the reverse direction with respect to the center of the flow path in the direction orthogonal to the flow path direction. Note that the first orifice hole and the fourth orifice hole were arranged at the center of the flow path. Otherwise, the configuration was the same as that of the embodiment.

[0038] In the water separation device of Comparative Example 2, as shown in FIG. 4B, one first to fourth orifice holes were respectively provided in the first to fourth partition walls on the downstream side of the first to fourth tanks. Further, all the first to fourth orifice holes were arranged at the center of the flow path. Otherwise, the configuration was the same as that of the embodiment.

[0039] In the water separation device of Comparative Example 1, since the third orifice hole on the upstream side of the second tank was arranged shifted to the left side of the flow path, as shown in FIG. 5A, even when the inflow amount of sewage was the normal inflow amount, the sewage overflowed from the left side of the second overflow weir of the second tank. Further, since the second orifice hole on the upstream side of the first tank was arranged shifted to the right side of the flow path, the sewage overflowed from the right side of the first overflow weir of the first tank. This is because the jet of sewage passing through the third orifice hole collided with the second partition wall and the water surface rose, causing water to overflow from the left side of the nearby second overflow weir, and also because the jet of sewage passing through the second orifice hole collided with the first partition wall and the water surface rose, causing water to overflow from the right side of the nearby first overflow weir.

[0040] Further, in the water separation device of Comparative Example 1, as shown in FIGS. 6A and 7A, from normal times to the heavy rain peak time, the amount of sewage overflowing from the overflow weir became excessive, and the interception amount tended to be less than the planned interception amount.

[0041] In the water separation device of Comparative Example 2, as shown in FIG. 5B, when the inflow amount of sewage was the normal inflow amount, no sewage overflow occurred. However, as shown in FIGS. 6B, 7B, and 8, at the heavy rain peak time, a phenomenon occurred in which the jet passing through the upstream orifice hole continued to pass through the downstream orifice hole without losing its momentum, resulting in the interception amount becoming larger than the planned interception amount which is the design value.

[0042] In contrast, in the water separation device of the embodiment, as shown in FIGS. 5C, 6C, and 7C, when the sewage inflow is the normal inflow volume, sewage overflow does not occur. During the heavy rain peak, sewage is overflowed for each of the first tank to the fourth tank, and the flow rate of the sewage passing through the orifice holes is gradually decreased. As a result, it was found that more accurate water separation control was possible compared to Comparative Example 1 and Comparative Example 2. There are two reasons for this. One reason is that the sewage jet is dispersed because the orifice holes are divided into two. Another reason is that the fourth orifice hole and the third orifice hole are arranged with a shift in the direction perpendicular to the flow path direction in the reverse direction, and the third orifice hole and the second orifice hole are also arranged with a shift in the direction perpendicular to the flow path direction in the reverse direction. As a result, as shown in FIG. 8 for the water separation device of Comparative Example 2, the phenomenon that the sewage jet continues to pass from the upstream orifice hole to the downstream orifice hole was prevented.

[0043] The accuracy of the water separation control in the water separation devices of Comparative Example 1, Comparative Example 2, and the embodiment was evaluated by the collection error according to the following formula (1). In the following formula (1), e s is the collection error (percentage), Q s is the collected volume [m ３ / s], Q s,d is the planned collected volume [m ３ / s]. e s = 100(Q s - Q s,d ) / Q s,d ・・・(1)

[0044] Table 1 shows the average value of the collection error e s at all inflow volumes at all times and the average value of the collection error e s at the maximum inflow volume during the heavy rain peak (600 s to 800 s) in the water separation devices of Comparative Example 1, Comparative Example 2, and the embodiment. Since the collection error e s is considered to be maximized at the time of the inflow volume during the heavy rain peak, it is organized in two ways: all time and heavy rain peak time.

[0045]

[0046] In the water separation device of Comparative Example 1, the collection error e in Table 1s From the average values, it was found that the amount of sewage overflow was excessive, so the amount of sewage collected was smaller than the planned amount of sewage collected. Also, in the water distribution device of Comparative Example 2, the sewage collection error e in Table 1 s From the average values, it was found that the amount of filtration was excessive.

[0047] The water distribution device in the example has a total inflow with a collection error e s The average value is 9.7%, and the blocking error e at the maximum inflow rate is s The average value was 11.1%, which was the best accuracy compared to Comparative Examples 1 and 2. In conventional water distribution devices, the shielding error e over the entire time was calculated to be 40-50% in theoretical calculations. s In addition to the occurrence of this, the planned amount of rainfall Q occurs during actual heavy rain. s,d several times the obstruction error e s It has also been pointed out that this can occur. Therefore, the water distribution device of the embodiment enables significantly more precise control of the water distribution flow rate compared to conventional water distribution devices.

[0048] (Second Embodiment) The water distribution device according to the second embodiment will be described with reference to Figure 9. In the second embodiment, components similar to those in the water distribution device according to the first embodiment are denoted by the same reference numerals and their descriptions are omitted, and the differences from the first embodiment will be described. In the water distribution device 40 of the second embodiment, the first to third overflow weirs 22C, 22B, and 22A are provided on one side of the flow path 20. In this embodiment, sewage that overflows from the first to third overflow weirs 22C, 22B, and 22A flows down from one side of the flow path 20.

[0049] (Third Embodiment) The water distribution device according to the third embodiment will be described with reference to Figure 10. In the third embodiment, components similar to those in the water distribution device according to the first embodiment are denoted by the same reference numerals and their descriptions are omitted, and the differences from the first embodiment will be described. The water distribution device 50 of the third embodiment has two adjustment tanks, a first adjustment tank 5B and a second adjustment tank 5A, and has a first bottom 51B, a second bottom 51A, a pair of first overflow weirs 52B, a pair of second overflow weirs 52A, a first partition wall 53B, a second partition wall 53A, a first orifice hole 54B, and a second orifice hole 54A. Two second orifice holes 54A are formed side by side in a direction perpendicular to the flow path direction (the width direction of the flow path). By using two adjustment tanks, it is possible to reduce the size of the housing 26.

[0050] (Fourth Embodiment) The water distribution device according to the fourth embodiment will be described with reference to Figure 11. In the fourth embodiment, components similar to those in the water distribution device according to the first embodiment are denoted by the same reference numerals and their descriptions are omitted, and the differences from the first embodiment will be described. The water distribution device 60 of the fourth embodiment has a first overflow weir 62B and a second overflow weir 62A provided on one side of the flow path 20, and has two adjustment tanks, a first adjustment tank 6B and a second adjustment tank 6A. The water distribution device 60 also has a first bottom 61B, a second bottom 61A, a first partition wall 63B, a second partition wall 63A, a first orifice hole 64B, and a second orifice hole 64A. Two second orifice holes 64A are formed side by side in a direction perpendicular to the flow path direction (the width direction of the flow path).

[0051] (Fifth Embodiment) The water distribution device according to the fifth embodiment will be described with reference to Figure 12. In the fifth embodiment, components similar to those in the water distribution device according to the first embodiment are denoted by the same reference numerals and their descriptions are omitted, and the differences from the first embodiment will be described. In the water distribution device 70 of the fifth embodiment, the third orifice hole 74A and the second orifice hole 74B are formed in pairs, side by side in the height direction (vertical direction) of the third partition wall portion 23A and the second partition wall portion 23B. By dividing the third orifice hole 74A and the second orifice hole 74B into two in this way, the energy of the sewage jet passing through is dispersed. In addition, the third orifice hole 74A and the second orifice hole 74B are formed offset in the height direction between the adjacent third partition wall portion 23A and the second partition wall portion 23B. This reduces the force of the sewage jet that has passed through the third orifice hole 74A on the upstream side, allowing the sewage to pass through the second orifice hole 74B on the downstream side.

[0052] Although the present invention has been described above with reference to embodiments, the present invention is not limited to the above embodiments, and various embodiments and modifications are possible. For example, in the first to fifth embodiments described above, an example in which the water distribution device is used in a combined sewer system was explained, but it can also be used in a separate sewer system in which rainwater and wastewater are carried in separate pipelines. For example, by connecting the rainwater pipe (inlet pipe), collection pipe (collection pipe), and discharge pipe of a separate sewer system to the water distribution device, it is possible to precisely distribute and collect the planned amount of rainwater to be collected for non-point load countermeasures. This makes it possible to effectively prevent non-point pollution.

[0053] Furthermore, by using the water distribution device of this disclosure in the retention ponds of combined sewer systems and separate sewer systems, it is possible to precisely divide the water into the maximum amount of sewage that can be discharged into public water bodies, the maximum amount of rainwater that can be discharged into public water bodies, and the sewage and rainwater that will flow into the retention pond.

[0054] Furthermore, as shown in Figure 13, the water distribution device of this disclosure can also be applied to a water intake system. The water intake system 3 has a water distribution device 30. This water distribution device 30 is connected to an inlet pipe 36 through which river water from the river 31 flows in via a water intake 32, a collection pipe 38 that flows the desired river water to the power plant 33, and a discharge pipe 37 that discharges the river water back into the river 31. The other components of the water distribution device 30 are the same as those of the water distribution device according to the first embodiment.

[0055] In this water intake system, the water distribution device 30 allows for high-precision water distribution of the river water flowing in from the inlet pipe 36 to the power plant 33, which then flows it to the collection pipe 38, into a desired amount of river water for intake and river water for discharge to the discharge pipe 37. Furthermore, this water intake system can also be used to distribute a desired amount of river water to a water supply system or agricultural irrigation canal instead of the hydroelectric power plant 33.

[0056] Furthermore, although the above embodiments and examples describe an example in which two orifice holes are formed in the partition wall, the number of orifice holes is not limited to two; any number is acceptable, and three or more may be formed. By forming multiple orifice holes, the energy of the sewage jet passing through the orifice holes is dispersed.

[0057] Furthermore, in the above embodiments and examples, we have described examples in which two orifice holes are formed offset in opposite directions in a direction perpendicular to the flow direction between adjacent partition walls. However, it is not always necessary to form multiple orifice holes offset in this way. As mentioned above, simply forming multiple orifice holes can provide the effect of dispersing the sewage jet passing through the orifice holes.

[0058] Furthermore, although the above embodiments and examples describe water distribution devices having two to four adjustment tanks, it is also possible to have five or more adjustment tanks. Having five or more adjustment tanks enables more precise water distribution control.

[0059] The first to fifth embodiments describe at least the following configurations: (1) A water distribution device comprising an inlet pipe into which flowing water flows, a collection pipe, and a discharge pipe, connected together, which divides the flowing water flowing in from the inlet pipe into flowing water to flow to the collection pipe and flowing water to flow to the discharge pipe, comprising: a flow path through which the flowing water flowing in from the inlet pipe flows out to the collection pipe; a plurality of overflow weirs erected on at least one of both sides of the flow path; a plurality of partition wall sections provided between the plurality of overflow weirs and between the overflow weirs and the collection pipe, each having an orifice hole; and a plurality of regulating tanks partitioned by the plurality of overflow weirs and the plurality of partition wall sections, wherein the discharge pipe into which the flowing water overflowing from the plurality of overflow weirs flows is connected below the plurality of regulating tanks, and the number of orifice holes formed in the partition wall sections provided between the plurality of overflow weirs is plurality. (2) The water distribution device according to (1), characterized in that the plurality of orifice holes are formed in a direction perpendicular to the flow direction and are offset in opposite directions in the direction perpendicular to the flow direction between adjacent partition wall portions. (3) A sewerage system comprising a combined sewer into which sewage flows, a collection pipe that carries sewage to a sewage treatment plant, and a discharge pipe, connected together, and having a water distribution device that divides the sewage flowing in from the combined sewer into sewage that flows to the collection pipe and sewage that flows to the discharge pipe, wherein the water distribution device comprises a flow path through which sewage flowing in from the combined sewer flows out to the collection pipe, a plurality of overflow weirs erected on at least one of both sides of the flow path, a plurality of partition wall sections provided between the plurality of overflow weirs and between the overflow weirs and the collection pipe, and having orifice holes formed therein, and a plurality of regulating tanks partitioned by the plurality of overflow weirs and the plurality of partition wall sections, wherein the discharge pipe into which sewage overflowing from the plurality of overflow weirs flows is connected below the plurality of regulating tanks, and the number of orifice holes formed in the partition wall sections provided between the plurality of overflow weirs is plurality. (4) The sewerage system according to (3), characterized in that the plurality of orifice holes are formed in a direction perpendicular to the flow direction and are offset in opposite directions in the direction perpendicular to the flow direction between adjacent partition wall portions.(5) A water intake system comprising an inlet pipe into which river water flows, a collection pipe, and a discharge pipe, connected together, and a water distribution device that divides the river water flowing in from the inlet pipe into river water to be discharged to the collection pipe and river water to be discharged to the discharge pipe, wherein the water distribution device comprises a flow path through which the river water flowing in from the inlet pipe flows out to the collection pipe, a plurality of overflow weirs erected on at least one of both sides of the flow path, a plurality of partition wall sections provided between the plurality of overflow weirs and between the overflow weirs and the collection pipe, and having orifice holes formed therein, and a plurality of regulating tanks partitioned by the plurality of overflow weirs and the plurality of partition wall sections, wherein the discharge pipe into which the river water overflowing from the plurality of overflow weirs flows is connected below the plurality of regulating tanks, and the number of orifice holes formed in the partition wall sections provided between the plurality of overflow weirs is plurality. (6) The water intake system according to (5), characterized in that the plurality of orifice holes are formed in a direction perpendicular to the flow direction and are offset in opposite directions in the direction perpendicular to the flow direction between adjacent partition wall portions.

[0060] Although the present disclosure has been described above with reference to embodiments, the present invention can be implemented in various forms and modifications without departing from the broad spirit and scope of the invention. Furthermore, the embodiments described above are for illustrative purposes only and do not limit the scope of the invention. In other words, the scope of the invention is indicated not by the embodiments, but by the claims. Various modifications made within the scope of the claims and the equivalent scope of the meaning of the invention are considered to be within the scope of the present invention.

[0061] This application claims priority based on Japanese Patent Application No. 2024-207858, filed on 29 November 2024, and incorporates the entire specification, claims, and drawings of Japanese Patent Application No. 2024-207858 by reference herein.

[0062] 1 Combined sewer system 3 Water intake system 2, 30, 40, 50, 60, 70 Water distribution device 5 Sewage treatment plant 6 Combined pipe (inlet pipe) 36 Inlet pipe 7, 37 Discharge pipe 8 Collection pipe (collection pipe) 38 Collection pipe 9 Discharge pipe for sewage treatment plant 20 Flow path 2A Third adjustment tank 2B Second adjustment tank 2C First adjustment tank 21A Third bottom 21B Second bottom 21C First bottom 22A Third overflow weir 22B Second overflow weir 22C First overflow weir 23A Third partition 23B Second partition 23C First partition 24A, 74A Third orifice hole 24B, 74B Second orifice hole 24C First orifice hole 26 Enclosure W Public water body 31 River 32 Water intake 33 Power plant

Claims

1. A water distribution device comprising an inlet pipe into which flowing water flows, a collection pipe, and a discharge pipe, connected together, for dividing the flowing water flowing in from the inlet pipe into flowing water to flow to the collection pipe and flowing water to flow to the discharge pipe, characterized in that it comprises a flow path through which the flowing water flowing in from the inlet pipe flows out into the collection pipe, a plurality of overflow weirs erected on at least one of both sides of the flow path, a plurality of partition wall sections provided between the plurality of overflow weirs and between the overflow weirs and the collection pipe, each having an orifice hole, and a plurality of regulating tanks partitioned by the plurality of overflow weirs and the plurality of partition wall sections, wherein the discharge pipe into which the flowing water overflowing from the plurality of overflow weirs flows is connected below the plurality of regulating tanks, and the number of orifice holes formed in the partition wall sections provided between the plurality of overflow weirs is plurality.

2. The water distribution device according to claim 1, characterized in that the plurality of orifice holes are formed in a direction perpendicular to the flow direction and are offset in opposite directions in the direction perpendicular to the flow direction between adjacent partition wall portions.

3. A sewerage system comprising a combined sewer into which sewage flows, a collection pipe that carries sewage to a sewage treatment plant, and a discharge pipe, connected together, and having a water distribution device that divides the sewage flowing in from the combined sewer into sewage that flows to the collection pipe and sewage that flows to the discharge pipe, wherein the water distribution device comprises a flow path through which sewage flowing in from the combined sewer flows out to the collection pipe, a plurality of overflow weirs erected on at least one of both sides of the flow path, a plurality of partition wall sections provided between the plurality of overflow weirs and between the overflow weirs and the collection pipe, and having orifice holes formed therein, and a plurality of regulating tanks partitioned by the plurality of overflow weirs and the plurality of partition wall sections, wherein the discharge pipe into which sewage overflowing from the plurality of overflow weirs flows is connected below the plurality of regulating tanks, and the number of orifice holes formed in the partition wall sections provided between the plurality of overflow weirs is plurality.

4. The sewerage system according to claim 3, characterized in that the plurality of orifice holes are formed in a direction perpendicular to the flow direction and are offset in opposite directions in the direction perpendicular to the flow direction between adjacent partition wall portions.

5. A water intake system comprising an inlet pipe into which river water flows, a collection pipe, and a discharge pipe, connected together, and having a water distribution device that divides the river water flowing in from the inlet pipe into river water to be discharged to the collection pipe and river water to be discharged to the discharge pipe, wherein the water distribution device comprises a flow path through which the river water flowing in from the inlet pipe flows out to the collection pipe, a plurality of overflow weirs erected on at least one of both sides of the flow path, a plurality of partition wall sections provided between the plurality of overflow weirs and between the overflow weirs and the collection pipe, and having orifice holes formed therein, and a plurality of regulating tanks partitioned by the plurality of overflow weirs and the plurality of partition wall sections, wherein the discharge pipe into which the river water overflowing from the plurality of overflow weirs flows is connected below the plurality of regulating tanks, and the number of orifice holes formed in the partition wall sections provided between the plurality of overflow weirs is plurality.

6. The water intake system according to claim 5, characterized in that the plurality of orifice holes are formed in a direction perpendicular to the flow direction and are offset in opposite directions in the direction perpendicular to the flow direction between adjacent partition wall portions.

Images