JP7598400B2 - Rainwater drainage system - Google Patents

Description

The present invention relates to a rainwater drainage device for draining rainwater.

Conventionally, a configuration has been proposed that improves the efficiency of rainwater drainage by inducing a siphon effect (see, for example, Patent Document 1).

For example, in the configuration shown in Patent Document 1, the siphon phenomenon was induced by a siphon pipe consisting of an elbow joint or a round gutter placed under the eaves gutter of a house.

Patent No. 4130616

However, in tall structures such as buildings, the pipes for draining rainwater are generally placed inside the structure, so vertical pipes that carry the rainwater down to the ground must be run through restricted locations such as the inside of walls or pillars.

For this reason, it may be necessary to use horizontal piping to guide rainwater from the inlet on the roof to the vertical pipes, but depending on the length of the horizontal piping, it may be difficult for the siphon phenomenon described in Patent Document 1 to occur.

The present invention aims to provide a rainwater drainage device that can more reliably induce the siphon phenomenon.

To achieve the above object, the rainwater drainage device according to the first invention comprises an inlet, a first piping section, and a second piping section. Rainwater flows into the inlet. The first piping section is connected to the inlet and is arranged along the vertical direction. The second piping section is connected to the first piping section at the first connection section and is arranged along the horizontal direction. The length of the first piping section from the first connection section to the inlet is 60 cm or more.

In this way, by setting the length from the inlet of the vertically arranged first piping section to the second piping section to 60 cm or more, it is possible to ensure a length of the second piping section that is suitable for use in buildings and other structures while still allowing the siphon phenomenon to occur.

This makes it possible to more reliably induce the siphon phenomenon in a configuration that can also be applied inside buildings.

In this specification, the term "vertical direction" does not have a strict meaning, but rather it is acceptable for the direction to be within a range that can be recognized as vertical according to social conventions, and it may be tilted. Also, the term "horizontal direction" does not have a strict meaning, but rather it is acceptable for the direction to be within a range that can be recognized as horizontal according to social conventions, and it may be tilted.

The rainwater drainage device according to the second invention is the rainwater drainage device according to the first invention, and has a plurality of inlets, first piping sections, and first connection sections. The distance between adjacent first connection sections is 15 m or less.

In this way, when rainwater flows into the second piping section from multiple inlets, the siphon effect can be generated by setting the length between the first connections to 15 m or less.

The rainwater drainage device according to the third invention is the rainwater drainage device according to the second invention, further comprising a third piping section. The third piping section is connected to the second piping section at the second connection section, and is arranged vertically below the second piping section. The length of the second piping section from the second connection section to the first connection section closest to the second connection section is 15 m or less.

In this way, even if rainwater flows into the second piping section from multiple inlets, the siphon effect can be generated by setting the length between the second connection section and the first connection section closest to the second connection section to 15 m or less.

The rainwater drainage device according to the fourth invention is the rainwater drainage device according to the first invention, further comprising a third piping section. The third piping section is connected to the second piping section at the second connection section, and is arranged vertically below the second piping section. The length of the third piping section from the second connection section to the first connection section is 15 m or less.

In this way, when rainwater flows into the second piping section from one inlet, the siphon effect can be created by setting the length between the first connections to 15 m or less.

The rainwater drainage device according to the fifth aspect of the invention is the rainwater drainage device according to any one of the first to fourth aspects of the invention, further comprising a siphon inducer. The siphon inducer is disposed at the inlet and induces the siphon phenomenon.

This makes it possible to more reliably cause the siphon effect to occur.

The present invention provides a rainwater drainage device that can more reliably induce the siphon phenomenon.

1 is a schematic diagram showing a configuration of a storm water drainage system according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the storm water drainage system of FIG. 1 near an inlet. 3A is a front view showing the configuration of a siphon induction section in the drainage device of FIG. 2 , and FIG. 3B is a plan view of the siphon induction section of FIG. 3A . FIG. 2 is a schematic diagram of the storm water drainage device of FIG. 1 . FIG. 1 shows a table of the results of Examples 1 to 8 and Comparative Examples 1 to 7. FIG. 11 is a schematic diagram of a rainwater drainage device according to a modified example of an embodiment of the present invention. FIG. 11 is a schematic diagram of a rainwater drainage device according to a modified example of an embodiment of the present invention.

The rainwater drainage device 10 according to an embodiment of the present invention will be described with reference to the drawings.

<1. Configuration>
FIG. 1 is a diagram showing the configuration of a rainwater drainage device 10 according to the present embodiment.

The rainwater drainage device 10 of this embodiment constitutes part of a rainwater drainage system 1 installed in a building 100, as shown in FIG. 1.

The structure 100 is, for example, a three-story building, with slabs 101 provided between the first and second floors and between the second and third floors.

(Rainwater drainage system 1)
The storm water drainage system 1 moves rainwater that has fallen on a roof 105 of a building 100 to the vicinity of the ground and drains it into a sewer pipe. As shown in Fig. 1, the storm water drainage system 1 includes two storm water drainage devices 10. The two storm water drainage devices 10 are disposed near opposite side surfaces 103 and 104 of the building 100.

(Rainwater drainage device 10)
The rainwater drainage device 10 has a plurality of inlets 11, a plurality of siphon induction sections 12, a plurality of vertical pipe sections 13, a horizontal pipe section 14, a vertical pipe section 15, and a drainage section 16.

(Inlet 11)
The inlet 11 is an opening formed in the rooftop 105, through which rainwater that has fallen onto the rooftop 105 flows.

Figure 2 is a side cross-sectional view showing the inlet 11 and the siphon inducer 12 described below. The inlet 11 shown in Figure 2 is the inlet 11 that is the furthest of the two inlets 11 from the vertical pipe section 15.

As shown in FIG. 2, the inlet 11 is formed in the bottom surface 102a of a recess 102 formed in the rooftop 105.

In this embodiment, each rainwater drainage device 10 has two inlets 11. The two inlets 11 of one rainwater drainage device 10 are arranged side by side along the edge 105a of the rooftop 105. The two inlets 11 of the other rainwater drainage device 10 are arranged side by side along the edge 105b opposite the edge 105a of the rooftop 105. In other words, the rooftop 105 is provided with four inlets 11, and the two inlets 11 of each rainwater drainage device 10 are arranged along the opposite edges 105a, 105b of the rooftop 105.

In addition, the ends 105a and 105b of the rooftop 105 may be inclined toward either of the directions along the ends. Also, the rooftop 105 may be inclined from the center toward the ends 105a and 105b.

In this embodiment, the inlet 11 is formed in the bottom surface 102a of the recess 102 formed in the rooftop 105, but it may be formed directly in the rooftop 105 without providing a recess 102.

(Siphon Inducing Unit 12)
As shown in FIG. 2 , the siphon inducer 12 is disposed so as to block the inlet 11 .

The material of the siphon inducer 12 can be, for example, an olefin resin such as PE (polyethylene) or PP (polypropylene), PVC resin, or a metal such as aluminum, an aluminum alloy, or stainless steel.

By using resin, aluminum, or aluminum alloy, a siphon inducer 12 with the desired shape can be obtained at low cost and with a light weight.

Figure 3(a) is a plan view of the siphon inducer 12, and Figure 3(b) is a cross-sectional view taken along the line AA' in Figure 3(a).

The siphon inducer 12 has a base portion 41, a lid portion 42, and a flow straightening fin 43.

As shown in Figs. 3(a) and 3(b), the base portion 41 has a circular bottom surface 41a, a drop outlet 41b formed at approximately the center of the bottom surface 41a for allowing rainwater to fall, and a cylindrical portion 41c. The drop outlet 41b is formed at the upper end of the cylindrical portion 41c. The cylindrical portion 41c is disposed in the vertical pipe portion 13.

As shown in Figures 3(a) and 3(b), the bottom surface 41a is an annular member with a drop opening 41b formed in the approximate center. A plurality of flow straightening fins 43 are arranged at equal angular intervals on the annular bottom surface 41a, centered on the drop opening 41b.

As shown in FIG. 3(a), the drop port 41b is a through hole formed in the center of the base portion 41, and is formed inside the cylindrical portion 41c. The drop port 41b is connected to the upper end of the vertical pipe portion 13, and allows rainwater that flows into the siphon inducer portion 12 from 360 degrees to fall into the vertical pipe portion 13.

As shown in Fig. 3(a) and Fig. 3(b), the tubular portion 41c is a cylindrical member, and its upper end is connected to the bottom surface 41a and is formed so as to protrude downward from the bottom surface 41a. The tubular portion 41c has a drop opening 41b formed inside.

As shown in Figures 3(a) and 3(b), the lid 42 is a circular plate-like member arranged above the base 41 concentrically with the drop opening 41b formed at the center of the base 41, and is supported by a number of flow straightening fins 43 erected on the bottom surface 41a of the base 41. As shown in Figure 3(b), the lid 42 is arranged above the base 41 (drop opening 41b) with a predetermined gap G (height) from the bottom surface 41a.

As shown in Figures 3(a) and 3(b), the multiple flow straightening fins 43 are provided on the bottom surface 41a of the base portion 41 to straighten the flow of rainwater flowing into the drop opening 41b. More specifically, as shown in Figure 3(a), the multiple flow straightening fins 43 are plate-shaped members arranged along a substantially vertical direction, and eight of them are provided at equal angular intervals on the circumference of a circle centered on the drop opening 41b on the bottom surface 41a.

The eight flow straightening fins 43 are arranged radially on the annular bottom surface 41a.

As a result, even if rainwater that has flowed into the gap G between the bottom surface 41a of the base portion 41 and the lid portion 42 in a vortex shape (see the dashed line in the figure) as shown in Figure 3(a), the rainwater can be rectified by the rectifying fins 43 and guided toward the center of the drop outlet 41b.

This prevents rainwater from flowing into the vertical pipe section 13 in a vortex shape, which would otherwise cause an air column to form in the center.

As a result, the flow straightening fins 43 prevent an air column from forming in the center of the rainwater flowing into the drop outlet 41b, effectively eliminating the factors that inhibit the siphon phenomenon that occurs within the vertical pipe section 13.

(Vertical piping section 13)
FIG. 4 is a schematic diagram of the rainwater drainage device 10. As shown in FIG.

The vertical pipe section 13 is disposed downward from each of the two inlets 11. As shown in FIG. 2, the vertical pipe section 13 has a pipe 21. The pipe 21 is a tubular member made of PE (polyethylene), and is disposed along a substantially vertical direction (also called an up-down direction) as shown in FIG. 2.

The upper end of the pipe 21 (also called the upper end 13a of the vertical pipe section 13) is connected to the edge of the inlet 11 from below and is connected to the inlet 11. The lower end of the pipe 21 (also called the lower end of the vertical pipe section 13) is connected to the horizontal pipe section 14.

For the pipe 21, for example, pipes with nominal diameters of 50A, 75A, 100A, 125A, 150A, 200A, etc. are used. The inner diameter is determined for each nominal diameter for each type of pipe. In this embodiment, the material of the pipe is, for example, polyethylene, but is not limited to this, and for example, polyvinyl chloride may be used.

The length L from the inlet 11 of the vertical pipe section 13 to the horizontal pipe section 14 is set to 60 cm or more. It can also be said that the length L from the inlet 11 of the vertical pipe section 13 to the connection sections 51 and 52 described below is set to 60 cm or more.

In this embodiment, the vertical pipe section 13 has one pipe 21, but it may have multiple pipes 21 and joints connecting them.

(Horizontal piping section 14)
The horizontal piping section 14 is disposed horizontally and connected to the lower ends of the two vertical piping sections 13. The vertical piping section 15, which will be described later, is connected to one end of the horizontal piping section 14. Although not shown in the figure, the horizontal piping section 14 is disposed at a slight incline so that the end on the vertical piping section 15 side is lower than the opposite end, and rainwater flowing in from the two vertical piping sections 13 is moved toward the vertical piping section 15.

Figure 4 is a diagram showing the configuration of the horizontal piping section 14. The horizontal piping section 14 has an elbow joint 31, a first pipe 32, a three-way joint 33, a second pipe 34, and an elbow joint 35, which are arranged in this order along the horizontal direction.

One end of the first pipe 32 is connected to the lower end of the vertical pipe section 13 farthest from the vertical pipe section 15 by an elbow joint 31. The other end of the first pipe 32 is connected to a three-way joint 33. The three-way joint 33 is connected to the lower end of the vertical pipe section 13 closer to the vertical pipe section 15 of the two vertical pipe sections 13 and one end of the second pipe 34. The other end of the second pipe 34 is connected to the upper end of the vertical pipe section 15 via an elbow joint 35.

Here, the connection parts of the two vertical pipe sections 13 to the horizontal pipe section 14 are designated as 51 and 52, and the connection part of the horizontal pipe section 14 to the vertical pipe section 15 is designated as 53, as shown in FIG. 4. Connection part 51 is located far from the vertical pipe section 15, and connection part 52 is located close to the vertical pipe section 15. In addition, if the distance of the horizontal pipe section 14 between connection parts 51 and 52 is designated as Y, and the distance of the horizontal pipe section 14 between connection parts 52 and 53 is designated as W, then Y and W are set to 15 m or less.

That is, the distance between adjacent connections 51, 52 is set to 15 m or less. Also, the distance of the horizontal piping section 14 from the connection 53 with the vertical piping section 15 of the horizontal piping section 14 to the closest connection 52 is set to 15 m or less.

For the first pipe 32 and the second pipe 34, pipes with nominal diameters of, for example, 50A, 75A, 100A, 125A, 150A, 200A, etc. are used. The inner diameter is determined for each nominal diameter for each type of pipe. In this embodiment, the material of the pipe is, for example, polyethylene, but is not limited to this, and for example, polyvinyl chloride may be used. Furthermore, pipes with the same nominal diameter may be used for the first pipe 32 and the second pipe 34, or pipes with different nominal diameters may be used. For example, pipes with larger nominal diameters may be used for the first pipe 32 and the second pipe 34 in that order.

(Vertical piping section 15)
The vertical pipe section 15 is disposed along the vertical direction, and its upper end is connected to the horizontal pipe section 14 at a connection section 53. The vertical pipe section 15 is disposed to penetrate the slab 101.

As shown in FIG. 4, the vertical pipe section 15 has a first pipe 61, a joint 62, and a second pipe 63. The upper end of the first pipe 61 is connected to the elbow joint 35. The lower end of the first pipe 61 is connected to the joint 62. The joint 62 is a reducer and a tubular member. The upper end of the second pipe 63 is connected to the joint 62. The lower end of the second pipe 63 is connected to the drain section 16. In this embodiment, the first pipe 61 and the second pipe 63 are made of, for example, polyethylene, but this is not limited thereto, and polyvinyl chloride may be used, for example. The joint 62 is made of polyethylene.

For example, the first pipe 61 may have a nominal diameter of 75A, 100A, 125A, 150A, 200A, etc. For example, the second pipe 63 may have a nominal diameter of 50A, 65A, 75A, 100A, 125A, 150A, etc. Although the first pipe 61 and the second pipe 63 may have the same nominal diameter, it is preferable that the first pipe 61 has a larger nominal diameter than the second pipe 63. For example, when the second pipe 63 has a nominal diameter of 75A, the first pipe 61 has a nominal diameter of 100A.

In this way, by using the joint 62 (reduced diameter section) to make the first pipe 61 a pipe with a larger nominal diameter than the second pipe 63, the pressure is relieved, suppressing the occurrence of cavitation, and the effect of reducing the nominal diameter is to increase resistance to flow, thereby reducing the sound of water impacting near the ground.

(Drainage section 16)
The drainage section 16 is connected to the lower end of the vertical pipe section 15, and drains rainwater to the outside of the building 100. The drainage section 16 has an elbow joint 71 and a pipe 72. The elbow joint 71 is connected to the lower end of the second pipe 63. The pipe 72 is connected to the elbow joint 71. The pipe 72 extends from the inside to the outside of the building 100, and is connected to a rainwater manhole (not shown). Rainwater that has fallen through the vertical pipe section 15 is drained to the outside of the building 100 through the pipe 72, and is drained to a sewer pipe via a rainwater manhole (not shown).

<2. Action>
Rainwater that falls on the roof 105 of the building 100 flows into the recess 102, passes through the siphon inducer 12 disposed at the inlet 11, and flows into the piping 21. Here, the siphon phenomenon occurs, filling the vertical piping 13, allowing a large amount of rainwater to be drained.

Rainwater flowing in from the multiple inlets 11 falls down the vertical pipe section 13, flows into the horizontal pipe section 14, and then flows into the vertical pipe section 15. Here, the pressure is relieved by making the first pipe 61 a pipe with a larger nominal diameter than the second pipe 63. This reduces the occurrence of cavitation.

Rainwater that falls down the vertical pipe section 15 is guided to the outside of the building 100 through the drainage section 16 and drained into the sewer pipe via a rainwater manhole.

3. Examples
In the present embodiment, Examples 1 to 8 and Comparative Examples 1 to 7 are shown in which the lengths L, Y and W of the rainwater drainage device 10 are changed.

Figure 5 is a table showing Examples 1 to 8 and Comparative Examples 1 to 7. When water was drained from the recess 102, it was confirmed whether the water flowed down without increasing in depth within the recess 102. If the water flowed down, it was indicated as good (○), and if the water level rose without flowing down, it was indicated as bad (×).

Example 1
In Example 1, a polyethylene pipe 21 with a nominal diameter of 50A was used, the size of the inlet 11 was 50A, the outer diameter of the pipe 21 was 60 mm, the pipe 32 was 50A, the pipe 34 was 65A, L was set to 0.6 m, Y was set to 1 m, W was set to 15 m, the pipe 61 was 65A (reference: length 2 m), the pipe 63 was reduced in diameter by a joint 62 to 50A, and a drainage experiment was performed at a flow rate of 10 L/s. The result was that the water did not rise in the recess 102 and flowed down, which was good (◯).

Example 2
In Example 2, a polyethylene pipe 21 with a nominal diameter of 50A was used, the size of the inlet 11 was 50A, the outer diameter of the pipe 21 was 60mm, the pipe 32 was 65A, the pipe 34 was 65A, L was set to 0.6m, Y to 15m, W to 1m, the pipe 61 was 65A (reference: length 2m), the pipe 63 was reduced in diameter to 50A by a joint 62, and a drainage experiment was performed at a flow rate of 10L/s. The result was that the water did not rise in the recess 102 and flowed down, which was good (◯).

Example 3
In Example 3, a polyethylene pipe 21 with a nominal diameter of 50A was used, the size of the inlet 11 was 50A, the outer diameter of the pipe 21 was 60mm, the pipe 32 was 65A, the pipe 34 was 65A, L was set to 0.6m, Y was set to 15m, W was set to 15m, the pipe 61 was 65A (for reference: length 2m), the pipe 63 was reduced in diameter to 50A by a joint 62, and a drainage experiment was performed at a flow rate of 10L/s. The result was that the water did not rise in depth in the recess 102 and flowed down, which was good (◯).

Example 4
In Example 4, a polyethylene pipe 21 with a nominal diameter of 75A was used, the size of the inlet 11 was 75A, the outer diameter of the pipe 21 was 89mm, the pipe 32 was 100A, the pipe 34 was 100A, L was set to 0.6m, Y was set to 15m, W was set to 1m, the pipe 61 was 100A (for reference: length 2m), the pipe 63 was reduced in diameter by a joint 62 to 100A, and a drainage experiment was performed at a flow rate of 30L/s. The result was that the water did not rise in depth in the recess 102 and flowed down, which was good (◯).

Example 5
In Example 5, a polyethylene pipe 21 with a nominal diameter of 75A was used, the size of the inlet 11 was 75A, the outer diameter of the pipe 21 was 89mm, the pipe 32 was 100A, the pipe 34 was 100A, L was set to 0.6m, Y was set to 1m, W was set to 15m, the pipe 61 was 100A (reference: length 2m), the pipe 63 was reduced in diameter by a joint 62 to 100A, and a drainage experiment was performed at a flow rate of 30L/s. The result was that the water did not rise in depth in the recess 102 and flowed down, which was good (◯).

Example 6
In Example 6, a polyethylene pipe 21 with a nominal diameter of 100A was used, the size of the inlet 11 was 75A, the outer diameter of the pipe 21 was 114mm, the pipe 32 was 125A, the pipe 34 was 125A, L was set to 0.6m, Y was set to 15m, W was set to 1m, the pipe 61 was 125A (for reference: length 1m), the pipe 63 was reduced in diameter by a joint 62 to 100A, and a drainage experiment was performed at a flow rate of 50L/s. The result was that the water did not rise in the recess 102 and flowed down, which was good (◯).

(Example 7)
In Example 7, a polyethylene pipe 21 with a nominal diameter of 100A was used, the size of the inlet 11 was 75A, the outer diameter of the pipe 21 was 114mm, the pipe 32 was 125A, the pipe 34 was 125A, L was set to 0.6m, Y was set to 1m, W was set to 15m, the pipe 61 was 125A (for reference: length 1m), the pipe 63 was reduced in diameter by a joint 62 to 100A, and a drainage experiment was performed at a flow rate of 50L/s. The result was that the water did not rise in the recess 102 and flowed down, which was good (◯).

(Example 8)
In Example 8, a polyethylene pipe 21 with a nominal diameter of 75A was used, the size of the inlet 11 was 75A, the outer diameter of the pipe 21 was 89mm, the pipe 32 was 100A, the pipe 34 was 100A, L was set to 0.6m, Y was set to 15m, W was set to 15m, the pipe 61 was 100A (for reference: length 2m), the pipe 63 was reduced in diameter by a joint 62 to 100A, and a drainage experiment was performed at a flow rate of 30L/s. The result was that the water did not rise in depth in the recess 102 and flowed down, which was good (◯).

(Comparative Example 1)
In Comparative Example 1, a polyethylene pipe 21 with a nominal diameter of 50A was used, the size of the inlet 11 was 50A, the outer diameter of the pipe 21 was 60mm, the pipe 32 was 65A, the pipe 34 was 65A, L was set to 0.6m, Y was set to 16m, W was set to 16m, the pipe 61 was 65A (reference: length 2m), the pipe 63 was reduced in diameter by a joint 62 to 50A, and a drainage experiment was performed at a flow rate of 10L/s. As a result, the water depth increased in the recess 102, and drainage was poor (x).

(Comparative Example 2)
In Comparative Example 2, a polyethylene pipe 21 with a nominal diameter of 75A was used, the size of the inlet 11 was 75A, the outer diameter of the pipe 21 was 89mm, the pipe 32 was 100A, the pipe 34 was 100A, L was set to 0.6m, Y was set to 16m, W was set to 16m, the pipe 61 was 100A (reference: length 2m), the pipe 63 was reduced in diameter by a joint 62 to 100A, and a drainage experiment was performed at a flow rate of 30L/s. As a result, the water depth increased in the recess 102, and drainage was poor (x).

(Comparative Example 3)
In Comparative Example 3, a polyethylene pipe 21 with a nominal diameter of 75A was used, the size of the inlet 11 was 75A, the outer diameter of the pipe 21 was 89mm, the pipe 32 was 100A, the pipe 34 was 100A, L was set to 0.5m, Y was set to 15m, W was set to 15m, the pipe 61 was 100A (reference: length 2m), the pipe 63 was reduced in diameter by a joint 62 to 100A, and a drainage experiment was performed at a flow rate of 30L/s. As a result, the water depth increased in the recess 102, and drainage was poor (x).

(Comparative Example 4)
In Comparative Example 4, a polyethylene pipe 21 with a nominal diameter of 100A was used, the size of the inlet 11 was 75A, the outer diameter of the pipe 21 was 89mm, the pipe 32 was 100A, the pipe 34 was 100A, L was set to 0.6m, Y was set to 16m, W was set to 16m, the pipe 61 was 125A (for reference: length 1m), the pipe 63 was reduced in diameter by a joint 62 to 100A, and a drainage experiment was performed at a flow rate of 50L/s. As a result, the water depth increased in the recess 102, and drainage was poor (x).

(Comparative Example 5)
In Comparative Example 5, a polyethylene pipe 21 with a nominal diameter of 100A was used, the size of the inlet 11 was 75A, the outer diameter of the pipe 21 was 89mm, the pipe 32 was 100A, the pipe 34 was 100A, L was set to 0.5m, Y was set to 15m, W was set to 15m, the pipe 61 was 125A (reference: length 1m), the pipe 63 was reduced in diameter by a joint 62 to 100A, and a drainage experiment was performed at a flow rate of 50L/s. As a result, the water depth increased in the recess 102, and drainage was poor (x).

(Comparative Example 6)
In Comparative Example 6, a polyethylene pipe 21 with a nominal diameter of 75A was used, the size of the inlet 11 was 75A, the outer diameter of the pipe 21 was 89mm, the pipe 32 was 100A, the pipe 34 was 100A, L was set to 0.6m, Y to 16m, W to 1m, the pipe 61 was 100A (reference: length 2m), the pipe 63 was reduced in diameter by a joint 62 to 100A, and a drainage experiment was performed at a flow rate of 30L/s. As a result, the water depth increased in the recess 102, and drainage was poor (x).

(Comparative Example 7)
In Comparative Example 7, a polyethylene pipe 21 with a nominal diameter of 75A was used, the size of the inlet 11 was 75A, the outer diameter of the pipe 21 was 89mm, the pipe 32 was 100A, the pipe 34 was 100A, L was set to 0.6m, Y was 1m, W was set to 16m, the pipe 61 was 100A (reference: length 2m), the pipe 63 was reduced in diameter by a joint 62 to 100A, and a drainage experiment was performed at a flow rate of 30L/s. As a result, the water depth increased in the recess 102, and drainage was poor (x).

From Example 8 and Comparative Example 3, it can be seen that drainage is improved by setting the distance L from the inlet 11 to the horizontal piping section 14 to 60 cm or more.

In addition, from Example 8 and Comparative Example 6, it can be seen that drainage is improved by setting the distance Y between adjacent connection parts 51, 52 to 15 m or less.

In addition, from Example 8 and Comparative Example 7, it can be seen that drainage is improved by setting the length W of the horizontal piping section 14 from the connection section 52 closest to the connection section 53 to 15 m or less.

<4. Features, etc.>
(1)
The rainwater drainage device 10 of this embodiment includes an inlet 11, a vertical pipe section 13 (an example of a first pipe section), and a horizontal pipe section 14 (an example of a second pipe section). Rainwater flows into the inlet 11. The vertical pipe section 13 is connected to the inlet 11 and arranged along the vertical direction. The horizontal pipe section 14 is connected to the vertical pipe section 13 at connections 51 and 52 (an example of a first connection section) and arranged along the horizontal direction. The length L of the vertical pipe section 13 from the connection section 51 to the inlet 11 and the length L of the vertical pipe section 13 from the connection section 52 to the inlet 11 are 60 cm or more.

In this way, by setting the length L from the inlet 11 of the vertically arranged vertical pipe section 13 to the horizontal pipe section 14 to 60 cm or more, it is possible to ensure a length of the horizontal pipe section 14 that is suitable for use in buildings and other structures while still allowing the siphon phenomenon to occur.

This makes it possible to more reliably induce the siphon phenomenon in a configuration that can also be applied inside buildings.

In this specification, the term "vertical direction" does not have a strict meaning, but rather it is acceptable for the direction to be within a range that can be recognized as vertical according to social conventions, and it may be tilted. Also, the term "horizontal direction" does not have a strict meaning, but rather it is acceptable for the direction to be within a range that can be recognized as horizontal according to social conventions, and it may be tilted.

(2)
In the rainwater drainage device 10 of this embodiment, a plurality of inlets 11, vertical pipe sections 13 (an example of a first pipe section), and connecting sections 51, 52 (an example of a first connecting section) are provided. The interval Y between adjacent connecting sections 51, 52 is 15 m or less.

In this way, when rainwater flows into the horizontal piping section 14 from multiple inlets 11, the siphon effect can be generated by setting the length between the connections 51, 52 to 15 m or less.

(3)
The rainwater drainage device 10 of this embodiment further includes a vertical pipe section 15 (an example of a third pipe section). The vertical pipe section 15 is connected to the horizontal pipe section 14 (an example of a second pipe section) at a connection section 53 (an example of a second connection section), and is disposed vertically below the horizontal pipe section 14. The length W of the horizontal pipe section 14 from the horizontal pipe section 14 to the connection section 52 closest to the connection section 53 is 15 m or less.

In this way, even if rainwater flows into the horizontal piping section 14 from multiple inlets 11, the siphon effect can be generated by setting the length W between the connection section 53 and the connection section 52 closest to the connection section 53 to 15 m or less.

(4)
The rainwater drainage device 10 of the present embodiment further includes a siphon induction unit 12. The siphon induction unit 12 is disposed at the inlet 11 and induces the siphon phenomenon.

This makes it possible to more reliably cause the siphon effect to occur.

5. Other embodiments
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the invention.

(A)
In the above embodiment, one rainwater drainage device 10 is provided with two sets of an inlet 11, a siphon induction section 12, and a vertical pipe section 13, but this is not limited to two sets, and three or more sets may be provided, or only one set may be provided.

Figure 6 is a schematic diagram showing a rainwater drainage device 10' in which three sets of an inlet 11, a siphon inducer 12, and a vertical pipe section 13 are provided. In the rainwater drainage device 10' shown in Figure 6, an additional set of an inlet 11, a siphon inducer 12, and a vertical pipe section 13 is provided between two sets.

In this case, the horizontal piping section 14' has an elbow joint 31, a first pipe 32, a three-way joint 36, a third pipe 37, a three-way joint 33, a second pipe 34, and an elbow joint 35, which are arranged in the horizontal direction. That is, unlike the horizontal piping section 14 of the embodiment, a three-way joint 36 and a third pipe 37 are further provided.

Unlike the above embodiment, the end of the first pipe 32 on the vertical pipe section 15 side is connected to a three-way joint 36, and the vertical pipe section 13 is connected to the three-way joint 36 from above. In addition, one end of the third pipe 37 is connected to the three-way joint 36, and the other end of the third pipe 37 is connected to the three-way joint 33.

As shown in FIG. 6, Y1 is the distance along the horizontal piping section 14' between the connection 51 farthest from the vertical piping section 15 and the connection 54 between the vertical piping section 13 and the horizontal piping section 14' in the middle of the three, and Y2 is the distance along the horizontal piping section 14' between the connection 54 and the connection 52. As in the above embodiment, W is the distance along the horizontal piping section 14' between the connection 52 and the connection 53. In this case, Y1, Y2, and W are set to 15 m or less. Note that Y1 and Y2 do not have to be the same distance as long as they are 15 m or less.

Also, FIG. 7 is a schematic diagram showing a rainwater drainage device 10'' in which only one set of an inlet 11, a siphon inducer 12, and a vertical pipe section 13 is provided. In this case, the horizontal pipe section 14'' (an example of a second pipe section) has an elbow joint 31, a first pipe 32, and an elbow joint 35 arranged in order along the horizontal direction. The elbow joint 31 connects the vertical pipe section 13 connected from above to the first pipe 32. The end of the first pipe 32 on the vertical pipe section 15 side is connected to the elbow joint 35, and the elbow joint 35 is connected to the vertical pipe section 15 (an example of a third pipe section). In this case, the distance W of the horizontal pipe section 14'' between the connection section 51 (an example of a first connection section) of the vertical pipe section 13 with the horizontal pipe section 14' and the connection section 53 (an example of a second connection section) between the horizontal pipe section 14'' and the vertical pipe section 15 is set to 15 m or less.

In this way, when rainwater flows into the horizontal piping section 14'' from one inlet 11, the siphon effect can be generated by setting the length between the connection section 51 and the connection section 53 to 15 m or less.

(B)
In the above embodiment, the length L from the inlet 11 of the two vertical piping sections 13 to the horizontal piping section 14 is set to the same length, but as long as a length of 60 cm or more is secured, the length from the inlet 11 of the vertical piping section 13 to the horizontal piping section 14 may be different.

(C)
In the above embodiment, the rainwater drainage devices 10 are provided only on two opposing side surfaces, but they may be provided near all four side surfaces.

(D)
In the above embodiment, the pipes are connected to each other by joints, but this is not limiting, and the pipes may be directly connected to each other.

(E)
In the rainwater drainage device 10 of the above embodiment, a pipe having a circular cross section perpendicular to the flow path direction (flow path cross section) is used, but the shape is not limited to a circular shape and may be an elliptical or rectangular shape, for example.

(F)
In the above embodiment, the pipe is described as being made of polyethylene, but the present invention is not limited to this. For example, other than polyethylene, other olefin resins such as PP (polypropylene) or other resins such as PVC (vinyl chloride) may be used.

Furthermore, the pipes are not limited to being made of resin, but may be made of metal.

(G)
In the above embodiment, the joint is described as being made of polyethylene, but the present invention is not limited to this. For example, other than polyethylene, other olefin resins such as PP (polypropylene) or other resins such as PVC (vinyl chloride) may be used.

Furthermore, the joints are not limited to being made of resin, but may be made of metal. When connecting a metal joint to a pipe, for example, a screw connection, a mechanical joint (e.g., a flexible joint), or a flange may be used.

(H)
In the above embodiment, the rainwater drainage device 10 is disposed inside the building 100, but this is not limited thereto, and the rainwater drainage device 10 may be disposed outdoors.

(I)
In the rainwater drainage device 10 of the above embodiment, the siphon induction unit 12 shown in Fig. 3(a) and Fig. 3(b) is provided, but is not limited to this. Also, if the siphon phenomenon occurs due to conditions such as the shape of the recess 102 or the rooftop 105, the siphon induction unit 12 does not have to be provided.

(J)
In the rainwater drainage device 10 of the above embodiment, the diameter is reduced midway through the vertical pipe section 15, but it does not have to be reduced in diameter.

The rainwater drainage device of the present invention has the effect of more reliably generating the siphon phenomenon and can be used as various types of drainage devices, etc.

10: Rainwater drainage device 11: Inlet 13: Vertical pipe section 14: Horizontal pipe section 51: Connection section 52: Connection section

Claims (5)

A rainwater drainage device that drains rainwater by siphoning,
An inlet through which rainwater flows in;
A first piping section connected to the inlet and disposed vertically;
a second piping section connected to the first piping section at a first connection section and disposed laterally;
A siphon inducer disposed at the inlet;
a third piping section connected downstream of the second piping section at a second connection section and disposed vertically ;
The length of the first piping section from the first connection section to the inlet is 60 cm or more,
The outer diameter of the first piping section is 60 mm or more and 114 mm or less,
The length of the second piping section from the second connection section to the first connection section closest to the second connection section is 15 m or less,
The siphon inducer is
The first piping section has a plurality of fins arranged in a radial direction thereof.
Storm water drainage system. A rainwater drainage device that drains rainwater by siphoning,
An inlet through which rainwater flows in;
A first piping section connected to the inlet and disposed vertically;
a second piping section connected to the first piping section at a first connection section and disposed laterally;
A siphon inducer disposed at the inlet;
a third piping section connected downstream of the second piping section at a second connection section and disposed vertically ;
The length of the first piping section from the first connection section to the inlet is 60 cm or more,
The outer diameter of the first piping section is 60 mm or more and 114 mm or less,
The length of the second piping section from the second connection section to the first connection section closest to the second connection section is 15 m or less,
The siphon inducer is
A lid portion is disposed above the inlet with a gap therebetween.
Storm water drainage system. The inlet, the first piping portion, and the first connection portion are provided in plurality,
The distance between adjacent first connection parts is 15 m or less.
A rainwater drainage device according to claim 1 or 2. The third piping section has a joint that reduces the inner diameter of the piping.
The rainwater drainage device according to any one of claims 1 to 3 . The third piping section has an outer diameter of 60 mm or more and 114 mm or less.
The rainwater drainage device according to any one of claims 1 to 4.

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