JP7566715B2 - Rainwater drainage piping structure - Google Patents

Description

This invention relates to a rainwater drainage piping structure that is installed in a building and drains rainwater from the upper floors to the floors below.

As is well known, in large-scale buildings such as factories and shopping centers, as buildings become more multi-purpose and complex, technology is becoming more widespread in which siphon-type drainage components are placed on roofs and balconies to efficiently drain rainwater from upper floors to lower floors.

A rainwater piping main system using a siphon-type drainage member creates a siphon effect in the pipe when rainwater flows in through the siphon-type drainage member, and this siphon effect creates a full pipe flow, improving drainage capacity (see, for example, Patent Document 1).

JP 2019-007250 A

However, in a rainwater piping system that uses the siphon effect, the pressure inside the main pipe is negative on the upper floors, but increases as you get closer to the lower floors, and on the lower floors, the pressure inside the pipe rises to positive pressure, making it increasingly difficult to merge the drainage from the branch pipes into the main pipe. In particular, if an elbow is provided at the bottom of the main pipe to change the direction of the drainage flow to the horizontal direction, the pressure inside the pipe on the lower floors tends to rise significantly when the elbow receives the drainage.
As a result, the locations where the wastewater can be merged into the main pipe are limited, and merging on lower floors where the pressure inside the pipe becomes positive is not possible.

The present invention was made in consideration of these circumstances, and aims to provide a rainwater drainage piping structure that can stably merge drainage water from a branch pipe into a main pipe at a junction located on an intermediate floor when using the siphon effect to drain rainwater from upper floors to lower floors.

In order to solve the above problems, the present invention proposes the following means.
One aspect of the present invention is a rainwater drainage piping structure that is placed in a building and drains rainwater, comprising a siphon-type drainage member, a main pipe through which rainwater flowing in from the siphon-type drainage member flows down, and a branch pipe connected to a junction located midway in the height direction of the main pipe and through which drainage water flows into the junction from the outside, wherein the main pipe comprises a first vertical pipe located on the upper side and connected to the siphon-type drainage member, and a second vertical pipe located below the first vertical pipe and having a larger flow path area than the first vertical pipe, wherein the junction is formed in the first vertical pipe, and the second vertical pipe is a protective pipe located below the junction and arranged at a distance between it and the outer wall portion of the first vertical pipe, and wherein the internal pipe pressure at the junction is negative.
In the rainwater drainage piping structure, a configuration may be adopted in which a nominal diameter of the second vertical pipe is set to be at least one size larger than a nominal diameter of the first vertical pipe.
In the rainwater drainage piping structure, a configuration may be adopted in which the confluence is located 10 m or less from the ground surface.
In the rainwater drainage piping structure, a configuration may be adopted in which the confluence is located on the third floor or lower.
In the rainwater drainage piping structure, a configuration may be adopted in which the lower side of the curing pipe is buried in the ground, and the lower end of the curing pipe is connected to an elbow buried in the ground.
The invention of aspect 1 of the present invention is a rainwater drainage piping structure that is placed in a building and drains rainwater from upper floors to lower floors, comprising a siphon-type drainage member placed on an upper floor, a main pipe through which rainwater flowing in from the siphon-type drainage member flows from the upper floor to the lower floor, and a branch pipe connected to a junction located midway in the height direction of the main pipe and through which drainage water from the outside flows into the junction, wherein the main pipe comprises a first vertical pipe that is placed on the upper side and connected to the siphon-type drainage member, and a second vertical pipe that is placed below the first vertical pipe and has a larger flow path area than the first vertical pipe.

According to the rainwater drainage piping structure of the present invention, the structure comprises a siphon-type drainage member arranged on an upper floor, a main pipe through which rainwater flowing in from the siphon-type drainage member flows down from the upper floor to the floor below, and a branch pipe connected to a junction located midway in the height direction of the main pipe and through which drainage water flows into the junction from the outside, and the main pipe comprises a first vertical pipe arranged on the upper side and connected to the siphon-type drainage member, and a second vertical pipe arranged below the first vertical pipe and having a larger flow path area than the first vertical pipe. Therefore, when draining rainwater from the upper floor to the floor below by applying the siphon effect, the drainage water can be stably merged from the branch pipe into the main pipe at the junction located on the midway floor.
As a result, branch pipes can be connected to the main pipe at lower levels in a building or on lower floors.

The invention of aspect 2 is a storm water drainage piping structure of aspect 1 , characterized in that the confluence is formed in the first vertical pipe, and the second vertical pipe is a curing pipe located below the confluence and arranged at a distance from the outer wall portion of the first vertical pipe.

In the rainwater drainage piping structure of this invention, the junction is formed in the first vertical pipe, and the second vertical pipe is a protective pipe located below the junction and spaced apart from the outer wall of the first vertical pipe, so that the first and second vertical pipes can be connected with a simple structure.

The invention of aspect 3 is a rainwater drainage piping structure of aspect 1 , characterized in that the confluence is formed in the first vertical pipe, and the second vertical pipe is connected to the first vertical pipe via an increaser arranged below the confluence.

According to the storm water drainage piping structure of this invention, the confluence is formed in the first vertical pipe, and the second vertical pipe is connected to the first vertical pipe via an increaser disposed below the confluence, so that the internal pressure at the confluence becomes negative, allowing the drainage water to stably merge from the branch pipe into the main pipe.

The invention of aspect 4 is a rainwater drainage piping structure of aspect 1 , characterized in that the confluence is formed in the second vertical pipe, and the second vertical pipe is connected to the first vertical pipe via an increaser arranged above the confluence.

According to the storm water drainage piping structure of this invention, the confluence is formed in the second vertical pipe, and the second vertical pipe is connected to the first vertical pipe via an increaser arranged above the confluence, so that the internal pressure at the confluence becomes negative, and the wastewater can be stably merged from the branch pipe into the main pipe. In addition, because the flow area in the main pipe is already large at the confluence, the flow rate of the wastewater merging at the confluence can be increased.

The invention of aspect 5 is a rainwater drainage piping structure of any one of aspects 1 to 4, characterized in that the nominal diameter of the second vertical pipe is set to be one size or more larger than the nominal diameter of the first vertical pipe.

In the rainwater drainage piping structure of this invention, the nominal diameter of the second vertical pipe is set to be at least one size larger than the nominal diameter of the first vertical pipe, so that the drainage water from the branch pipes can be efficiently merged at the junction.

The invention described in aspect 6 is the rainwater drainage piping structure of any one of aspects 1 to 5, characterized in that the confluence is located 10 m or less from the ground surface.

According to the rainwater drainage piping structure of the present invention, the confluence is located 10 m or less from the ground surface, so that the confluence can be located at a low position in the building.
As a result, the degree of freedom in designing the storm water drainage piping structure can be improved.

The invention described in aspect 7 is a rainwater drainage piping structure according to any one of aspects 1 to 5, characterized in that the confluence is located on the third floor or lower.

According to the rainwater drainage piping structure of the present invention, the confluence is located on the third floor or lower, so that the confluence can be located at a low position in the building.
As a result, the degree of freedom in designing the storm water drainage piping structure can be improved.

The rainwater drainage piping structure of this invention allows the drainage water to stably merge from the branch pipe into the main pipe at a junction located on an intermediate floor when using the siphon effect to drain rainwater from upper floors to lower floors.

1 is a conceptual diagram illustrating an example of a schematic configuration of a storm water drainage system according to a first embodiment of the present invention. FIG. 2 is a perspective view illustrating an example of a schematic configuration of a siphon-type drainage member applied to the rainwater drainage system according to the first embodiment. FIG. 2 is a side view illustrating an example of a schematic configuration of a siphon-type drainage member applied to the rainwater drainage system according to the first embodiment. 1 is a schematic diagram illustrating a schematic configuration of a storm water drainage system according to a first embodiment. FIG. FIG. 5 is a schematic diagram illustrating the schematic configuration of a storm water drainage system according to a second embodiment of the present invention. FIG. 11 is a schematic diagram illustrating the schematic configuration of a storm water drainage system according to a third embodiment of the present invention. FIG. 13 is a conceptual diagram illustrating an example of a schematic configuration of a storm water drainage system according to a fourth embodiment of the present invention. FIG. 13 is a vertical cross-sectional view illustrating an example of a schematic configuration of a siphon-type drainage member applied to a rainwater drainage system according to a fourth embodiment. FIG. 13 is a perspective view illustrating an example of a schematic configuration of a siphon-type drainage member applied to a rainwater drainage system according to a fourth embodiment. FIG. 1 is a conceptual diagram illustrating a schematic configuration of a storm water drainage system used in an embodiment of the present invention. FIG. 2 is a conceptual diagram illustrating a specific configuration of a storm water drainage system in an embodiment. FIG. 2 is a pressure distribution diagram illustrating the internal pressure of the main pipe of the storm water drainage system related to Verification Test 1 in the examples. FIG. 13 is a diagram illustrating the confluence flow rate of the branch pipe of the storm water drainage system related to verification test 2 in the examples.

First Embodiment
Hereinafter, a rainwater drainage system (rainwater drainage piping structure) according to a first embodiment will be described with reference to Figs. 1 to 4 .
Fig. 1 is a conceptual diagram for explaining an example of a schematic configuration of a storm water drainage system according to the first embodiment. Fig. 2 is a vertical cross-sectional view for explaining an example of a schematic configuration of a siphon-type drainage member applied to the storm water drainage system according to the first embodiment, and Fig. 3 is a perspective view. Fig. 4 is a schematic diagram for explaining the schematic configuration of the storm water drainage system according to the first embodiment.

In Figures 1 to 4, reference numeral 10 denotes a building, reference numeral 100 denotes a rainwater drainage system (rainwater drainage piping structure), reference numeral 20 denotes a siphon-type drainage member, reference numeral 120 denotes the rainwater piping body, reference numeral 121 denotes a horizontal pipe, reference numeral 122 denotes a main pipe, reference numeral 123 denotes a first vertical pipe, reference numeral 125 denotes a curing pipe (second vertical pipe), and reference numeral 150 denotes a branch pipe.

As shown in FIG. 1, a rainwater drainage system (rainwater drainage piping structure) 100 is applied to, for example, an eight-story building 10 (for example, 24 m high).
The building 10 may be, for example, a factory or shopping center that is 20 m or more in height, a warehouse, or a large parking lot.

The rainwater drainage system 100 further includes, for example, a siphon-type drainage member 20, a rainwater piping main body 120 that drains rainwater flowing in from the siphon-type drainage member 20 toward the lower floors, and a branch pipe 150 connected to the rainwater piping main body 120 at a junction 120T on an intermediate floor.
The storm water drainage system 100 is configured to drain the drainage water flowing down from the upper floors and the drainage water combined with the branch pipe 150 into a storm water inlet 160 buried underground.
The rainwater that flows into the rainwater inlet 160 is discharged outside the system via a pipe 161.

As shown in FIG. 1 , a siphon-type drainage member 20 (drainage member) is provided inside a large rain gutter 11 arranged at the eaves of the roof of a building 10 .
The gutter 11 receives and drains rainwater that flows down from the eaves of the roof. The gutter 11 is an extrusion molded product of synthetic resin such as rigid polyvinyl chloride resin, ABS, or AES. The gutter 11 is formed with a groove-shaped cross section in which a front wall 11B stands upright from the front end of a flat bottom wall 11A, and a rear wall 11C stands upright from the rear end of the bottom wall 11A. The gutter 11 is suspended, for example, by a gutter hanger (not shown) attached to a fascia board (not shown).

The siphon-type drainage member 20 shown in FIG. 2 is a drainage member with high drainage function to improve the drainage capacity of rainwater that flows into the rain gutter 11 during heavy rain. The siphon-type drainage member 20 is an injection-molded product of synthetic resin such as rigid polyvinyl chloride resin, polycarbonate, ABS, AES, etc. Note that it is not limited to synthetic resin, and may be made of cast iron using a mold.

The siphon-type drainage member 20 comprises a plate-shaped cover member 21, an attachment tube 22 with a drop opening 22a at the inside of the upper end, and a number of vertical ribs 23 that connect the cover member 21 and the attachment tube 22 and are spaced apart in the circumferential direction at positions that do not overlap the drop opening 22a when viewed from above.

The mounting tube 22 penetrates the bottom wall 11A of the gutter 11 in the vertical direction. A flange 22D is provided at the upper end of the mounting tube 22. The flange 22D is disposed on the upper surface of the bottom wall 11A and is supported from below by the bottom wall 11A. The portion formed between the outer periphery of the cover member 21 and the outer periphery of the flange 22D becomes the inflow opening 20A that allows rainwater accumulated in the gutter 11 to flow into the opening of the drop port 22a.

The vertical ribs 23 connect the flange 22D of the mounting tube 22 to the outer periphery of the cover member 21. The vertical ribs 23 rectify the rainwater flowing from the inlet opening 20A to the drop opening 22a.
The cover member 21 is supported by the mounting tube 22 via a plurality of vertical ribs 23. The cover member 21 is disposed inside the rain gutter 11, and is installed at a position spaced above the drop opening portion 22a.

In addition, the siphon-type drainage member 20 suppresses the formation of an air column near the center of the rainwater (drainage) that flows into the downflow portion 22a due to the siphon effect, thereby allowing the rainwater to flow efficiently toward the floor below.
The configuration of the siphon-type drainage member 20 is merely an example, and the configuration can be set arbitrarily.

As shown in FIG. 3, an elbow 121L is installed downstream of the siphon-type drainage member 20. The elbow 121L connects the siphon-type drainage member 20 to the rainwater piping main body 120 (horizontal piping 121).

As shown in FIGS. 1 and 4 , the rainwater pipe body 120 includes, for example, a horizontal pipe 121 and a main pipe (vertical pipe) 122 .
In addition, a junction 120T is formed in the main pipe (vertical piping) 122 midway in the height direction, and is configured to be able to merge the drainage water from the branch pipe 150. The junction 120T is a joint that joins a portion of the main pipe 122 located above the junction 120T with a portion located below the junction 120T. The junction 120T is formed by a tee (90° Y-shaped pipe), and one of the receiving ports of the junction 120T is connected to the branch pipe 150.

The horizontal pipe 121 is, for example, a straight pipe arranged along a substantially horizontal direction, and is connected to the main pipe 122 via an elbow (not shown).
The horizontal pipe 121 is configured to drain the rainwater that flows in from the siphon-type drainage member 20 into the main pipe 122.

As shown in Figures 1 and 4, the main pipe 122 includes, for example, a first vertical pipe 123 and a curing pipe (second vertical pipe) 125 arranged below the first vertical pipe.

The first vertical pipe 123 is, for example, a straight circular pipe made of hard PVC with a nominal diameter of 100A, and is arranged along the vertical direction of the building.
In this embodiment, a junction 120T is formed midway in the height direction of the first vertical pipe 123.
In addition, the lower portion of the first vertical pipe 123 is inserted into a curing pipe (second vertical pipe) 125 with a gap therebetween.
The material and size (nominal diameter) of the first vertical pipe 123 can be set arbitrarily. Also, a configuration in which no gap is formed between the first vertical pipe 123 and the curing pipe (second vertical pipe) 125 may be adopted.

The protective pipe (second vertical pipe) 125 is composed of, for example, a hard PVC circular straight pipe and has a larger flow path area than the first vertical pipe 122.
Specifically, in this embodiment, the curing pipe 125 is formed with a nominal diameter 125A that is one size larger than the first vertical pipe 123.

In addition, it is preferable that the curing pipe (second vertical pipe) 125 is arranged, for example, concentrically with the first vertical pipe 123, and that a radially equal gap is formed between the outer peripheral surface of the first vertical pipe 123 and the inner peripheral surface of the curing pipe 125 around the entire circumference.

In addition, the height of the upper opening (vertical pipe connection part) of the curing pipe (second vertical piping) 125 can be set as desired, but it is preferable for it to open to a height of, for example, 10 m or less from the ground, and it is even more preferable for it to open to a height of 2 m or less from GL (ground level).
In addition, it is preferable that the upper opening of the curing pipe (second vertical piping) 125 is located at a position lower than the third floor of the building 10, for example.
Furthermore, it is more preferable that the upper opening of the curing pipe 125 is located, for example, on the second floor or lower of the building 10, and it is even more preferable that it is located on the first floor.

In this embodiment, the lower side of the curing pipe 125 is buried in the ground and is arranged so as to rise up from the ground.
In addition, the curing pipe 125 is connected to a rainwater manhole 160 via, for example, an elbow 126, a connecting pipe 127, and an elbow 128, so that wastewater flowing down from the first vertical pipe 123 is discharged into the rainwater manhole 160.
In addition, it is preferable that a distance of 1 m or more, preferably 300 mm or more, is formed between the elbow 126 and the lower opening of the first vertical pipe 123.

The material of the curing pipe (second vertical piping) 125 can be set arbitrarily.
In addition, it is possible to arbitrarily set the size (nominal diameter) and flow path area of the curing pipe (second vertical pipe) 125. For example, the nominal diameter of the curing pipe 125 may be set to be two or more sizes larger than the nominal diameter of the first vertical pipe 123.
In addition, the flow path area of the curing pipe 125 may be set to be larger than the flow path area of the first vertical pipe 123 by an area difference of less than one size in nominal diameter, or may be set to an area difference of more than one size.
In addition, it is possible to arbitrarily set whether or not the protective pipe (second vertical pipe) 125 is concentric with the first vertical pipe 123, and the protective pipe 125 and the first vertical pipe 123 may be arranged eccentrically.

The branch pipe 150 is configured to make rainwater that flows into the branch pipe 150 from the large eaves 10c located on the third floor of the building 10 merge with the first vertical pipe 123 at the junction 120T. Note that the rainwater that flows into the branch pipe 150 is not limited to rainwater that flows in from the large eaves 10c, and may be, for example, rainwater that flows in from a balcony or a driveway provided on the building 10 (for example, a driveway that is provided on the periphery of the building 10 and thus has a part exposed to the outdoors).
In this embodiment, the junction 120T is located, for example, on the third floor of the building 10, and is set, for example, at a height of 10 m or less from the ground surface.

According to the rainwater drainage system (rainwater drainage piping structure) 100 of the first embodiment, the main pipe 122 is provided with a first vertical pipe 123 arranged on the upper side, and a protective pipe (second vertical pipe) 125 arranged on the lower side of the first vertical pipe 123, and the protective pipe 125 is formed with a nominal diameter 125A, which is one size larger than the first vertical pipe 123, and has a flow path area larger than the first vertical pipe 123. Therefore, when drainage water flows down from upper floors to lower floors by utilizing the siphon effect, it is possible to suppress the internal pressure of the main pipe 122 from rising to a positive pressure.
As a result, the wastewater can be stably merged from the branch pipe 150 into the main pipe 222 at the junction 120T.

Furthermore, according to the storm water drainage system 100 of the first embodiment, for example, at the junction 120T formed on a low floor below the third floor or below 10 m above ground level, the drainage water from the branch pipe 150 can be stably merged into the main pipe 122.
As a result, the branch pipe 150 can be connected to the main pipe 122 at a lower position or on a lower floor of the building 10 .

In addition, according to the storm water drainage system 100 of the first embodiment, the junction 120T is formed midway in the height direction of the first vertical pipe 123, the protective pipe 125 is positioned below the junction 120T, and the protective pipe 125 is arranged at a distance from the outer wall surface of the first vertical pipe 123, so that the rain water can be stably discharged to the storm water inlet 160 with a simple structure. Note that even in such a configuration in which the protective pipe 125 is positioned below the junction 120T, it has been confirmed that the drainage water from the branch pipe 150 is reliably merged into the main pipe 122, for example, if the flow rate of the drainage water merging from the branch pipe 150 to the junction 120T is 5 L/s (liters per second) or less.

Furthermore, according to the storm water drainage system 100 of the first embodiment, by forming the confluence section 120T at a height of 10 m or less from the ground surface, it is possible to place it at an inconspicuous low position in the building 10.
Furthermore, according to the storm water drainage system 100 of the first embodiment, a junction 120T can be formed on the lower floors of the building 10, such as the third floor or lower, thereby improving the design freedom of the storm water drainage system (storm water drainage piping structure) 100.

Second Embodiment
Hereinafter, a rainwater drainage system (rainwater drainage piping structure) according to a second embodiment of the present invention will be described with reference to FIG.
Fig. 5 is a schematic diagram illustrating the schematic configuration of a storm water drainage system according to the second embodiment. In Fig. 5, reference numeral 200 denotes a storm water drainage system (storm water drainage piping structure), reference numeral 220 denotes a storm water piping body, reference numeral 121 denotes a horizontal piping, reference numeral 222 denotes a main pipe, reference numeral 223 denotes a first vertical piping, reference numeral 225 denotes a second vertical piping, reference numeral 222S denotes an increaser, and reference numeral 220T denotes a junction.

The rainwater drainage system (rainwater drainage piping structure) 200 is applied to, for example, an eight-story building 10.
The rainwater drainage system 200 also includes, for example, a siphon-type drainage member (not shown), a rainwater piping main body 220 that drains rainwater flowing in from the siphon-type drainage member toward lower floors, and a branch pipe 150 connected to a junction 220T of the rainwater piping main body 220 on an intermediate floor (for example, the third floor).

The storm water drainage system 200 is configured to merge the drainage water flowing down from the upper floors and the drainage water from the branch pipe 150 at a junction 220T and drain the water into the storm water inlet 160.
The siphon type drainage member and the rainwater catch basin 160 are similar to the siphon type drainage member 110 and the rainwater catch basin 160 in the first embodiment, so a description thereof will be omitted.

As shown in FIG. 5 , the rainwater pipe body 220 includes, for example, a horizontal pipe 121 and a main pipe (vertical pipe) 222 .
In addition, a junction 220T is formed in the main pipe (vertical piping) 222, and is configured so that the drainage water from the branch pipe 150 joins with the junction 220T. The junction 220T is a joint that joins a portion of the main pipe 222 located above the junction 220T with a portion located below the junction 220T. The junction 220T is formed by a tee (90° Y-shaped pipe), and one of the receiving ports of the junction 220T is connected to the branch pipe 150.
The horizontal pipe 121 is the same as that in the first embodiment, so it is given the same reference numeral and the description thereof is omitted.

As shown in FIG. 5, the main pipe 222 includes, for example, a first vertical pipe 223, a second vertical pipe 225 arranged below the first vertical pipe 223, and an increaser 222S.

The first vertical pipe 223 is, for example, a straight circular pipe made of hard PVC with a nominal diameter of 100A, and is arranged along the vertical direction of the building.
In this embodiment, a junction 220T is formed midway in the height direction of the first vertical pipe 223.
In addition, the lower end of the first vertical pipe 223 is connected to the second vertical pipe 225 via an increaser 222S.
The material and size (nominal diameter) of the first vertical pipe 223 can be set arbitrarily.

The second vertical pipe 225 is, for example, a straight circular pipe made of hard PVC, has a larger flow area than the first vertical pipe 223, and is arranged along the vertical direction of the building 10. Specifically, the second vertical pipe 225 is, for example, formed with a nominal diameter of 125A, which is one size larger than the first vertical pipe 223.

The increaser 222S is formed, for example, from a hard PVC resin and is configured as a diameter expansion joint having one end (upper side) formed to a nominal diameter of 100A and the other end (lower side) formed to a nominal diameter of 125A.
The first vertical pipe 223 and the second vertical pipe 225 are connected to form a portion of the main pipe 222 where the flow path area is expanded from a nominal diameter of 100A to a nominal diameter of 125A.
The material for forming the increaser 222S can be arbitrarily selected.

In addition, the height of the connection part (vertical pipe connection part) where the increaser 222S is arranged can be set arbitrarily, but it is preferable to set it to, for example, 10 m or less from the ground.
Furthermore, the height of the increaser 222S is, for example, preferably placed on the third floor or lower of the building 10, more preferably placed on the second floor or lower, and even more preferably placed on the first floor.

In addition, in this embodiment, the lower side of the second vertical pipe 225 is buried in the ground and is connected to the rainwater inlet 160 via, for example, an elbow 126, a connecting pipe 127, and an elbow 128.

The material of the second vertical pipe 225 can be set arbitrarily.
In addition, it is possible to arbitrarily set the size (nominal diameter) and flow path area of the second vertical pipe 225. For example, the nominal diameter of the second vertical pipe 225 may be set to be two or more sizes larger than the nominal diameter of the first vertical pipe 223.
In addition, the flow path area of the second vertical pipe 225 may be set to be larger than the flow path area of the first vertical pipe 223 by an area difference of less than one size in nominal diameter, or may be set to an area difference of more than two sizes.

The branch pipe 150 is configured to cause rainwater that flows into the branch pipe 150 from, for example, the large eave 10c to merge with the first vertical pipe 223 at the junction 220T.
In this embodiment, the junction 220T is located, for example, on the third floor of the building 10, and is set, for example, at a height of 10 m or less from the ground surface.

According to the rainwater drainage piping structure (drainage piping structure) 200 of the second embodiment, the junction 220T is formed in the first vertical pipe 223, and the second vertical pipe 225 is connected to the first vertical pipe 223 via the increaser 222S below the junction 220T, so that the internal pressure at the junction 220T becomes negative, and the drainage can be stably merged from the branch pipe 150 to the main pipe 222.

Third Embodiment
Hereinafter, a rainwater drainage system (rainwater drainage piping structure) according to a third embodiment of the present invention will be described with reference to Fig. 6. Fig. 6 is a schematic diagram illustrating the schematic configuration of the rainwater drainage system (rainwater drainage piping structure) according to the third embodiment.
In FIG. 6 , reference numeral 300 indicates a rainwater drainage system (rainwater drainage piping structure), reference numeral 320 indicates the rainwater piping body, reference numeral 121 indicates a horizontal piping, reference numeral 322 indicates a main pipe, reference numeral 323 indicates a first vertical piping, reference numeral 325 indicates a second vertical piping, reference numeral 322S indicates an increaser, reference numeral 320T indicates a junction, and reference numeral 150A indicates a branch pipe.

The rainwater drainage system (rainwater drainage piping structure) 300 is applied to, for example, an eight-story building 10.
The rainwater drainage system 300 also includes, for example, a siphon-type drainage member (not shown), a rainwater piping main body 320 that drains rainwater flowing in from the siphon-type drainage member toward lower floors, and a branch pipe 150A connected to a junction 320T of the rainwater piping main body 320 on an intermediate floor (for example, the third floor).
The storm water drainage system 300 is configured to drain the drainage water flowing down from the upper floors and the drainage water combined with the branch pipe 150A into a storm water inlet 160 buried underground.
The siphon-type drainage member and the rainwater catch basin 160 are similar to those in the first embodiment, and therefore their explanation will be omitted.

As shown in FIG. 6 , the rainwater piping body 320 includes, for example, a horizontal piping 121 and a main pipe (vertical piping) 322 .
In addition, a junction 320T is formed in the main pipe (vertical piping) 322, and is configured so that the drainage water from the branch pipe 150A joins with the junction 320T. The junction 320T is a joint that joins a portion of the main pipe 322 located above the junction 320T with a portion located below the junction 320T. The junction 320T is formed by a tee (90° Y-shaped pipe), and one of the receiving ports of the junction 320T is connected to the branch pipe 150A.
The horizontal pipe 121 is similar to that in the first embodiment, and therefore the description thereof will be omitted.

As shown in FIG. 6, the main pipe 322 includes, for example, a first vertical pipe 323, a second vertical pipe 325 arranged below the first vertical pipe 323, and an increaser 322S.

The first vertical pipe 323 is, for example, a straight circular pipe made of hard PVC with a nominal diameter of 100A, and is arranged along the vertical direction of the building.
In this embodiment, an increaser 322S and a junction 320T are connected to the lower end of the first vertical pipe 323 in this order.
In addition, the first vertical pipe 323 is connected to the second vertical pipe 325 via an increaser 322S and a junction 320T.

A branch pipe 150A is connected to the junction 320T.
The material and size (nominal diameter) of the first vertical pipe 323 can be set arbitrarily.

The second vertical pipe 325 is, for example, a straight circular pipe made of hard PVC, has a larger flow area than the first vertical pipe 322, and is arranged along the vertical direction of the building 10. Specifically, the second vertical pipe 325 is formed with a nominal diameter of 125A, which is one size larger than the first vertical pipe 323.

The increaser 322S is formed, for example, from a hard PVC resin and is configured as a diameter expansion joint having one end (upper side) formed to a nominal diameter of 100A and the other end (lower side) formed to a nominal diameter of 125A.
The first vertical pipe 323 and the second vertical pipe 325 are connected via a junction 320T to form a portion of the main pipe 322 where the flow path area is expanded from a nominal diameter of 100A to a nominal diameter of 125A.
The material for forming the increaser 322S can be arbitrarily selected.

Furthermore, the height of the connection part (vertical pipe connection part) where the increaser 322S is arranged can be set arbitrarily, but it is preferable that it is arranged, for example, 10 m or less above the ground.
In addition, the height of the increaser 322S is, for example, preferably placed on the third floor or lower of the building 10, more preferably placed on the second floor or lower of the building 10, and even more preferably placed on the first floor.

In addition, in this embodiment, the lower side of the second vertical pipe 325 is buried in the ground and is connected to the rainwater inlet 160 via, for example, an elbow 126, a connecting pipe 127, and an elbow 128.

The material of the second vertical pipe 325 can be set arbitrarily.
In addition, it is possible to arbitrarily set the size (nominal diameter) and flow path area of the second vertical pipe 325. For example, the nominal diameter of the second vertical pipe 325 may be set to be two or more sizes larger than the nominal diameter of the first vertical pipe 323.
In addition, the flow path area of the second vertical pipe 325 may be set to be larger than the flow path area of the first vertical pipe 323 by an area difference of less than one size in nominal diameter, or may be set to an area difference of more than one size.

The branch pipe 150A is configured to cause rainwater that flows into the branch pipe 150A from, for example, the large eave 10c to merge with the first vertical pipe 323 at the junction 320T.
In this embodiment, the junction 320T is located, for example, on the third floor of the building 10, and is set, for example, at a height of 10 m or less from the ground surface.

According to the rainwater drainage system (rainwater drainage piping structure) 300 of the third embodiment, the confluence 320T is formed in the second vertical pipe 325, and the second vertical pipe 325 is connected to the first vertical pipe 323 via an increaser 320S arranged above the confluence 320T, so that the internal pressure at the confluence 320T becomes negative pressure, and the drainage can be stably merged from the branch pipe 150 to the main pipe 322.
In addition, since the flow path area in the main pipe 322 is already large at the junction 320T, the flow rate of the wastewater merging at the junction 320T can be increased. In this case, it has been confirmed that the wastewater from the branch pipe 150A is reliably merged into the main pipe 122 even if the flow rate of the wastewater merging from the branch pipe 150A to the junction 320T is 5 L/s (liters per second) or more.

Fourth Embodiment
A rainwater drainage system (rainwater drainage piping structure) according to a fourth embodiment of the present invention will be described below with reference to Figs.
Fig. 7 is a conceptual diagram for explaining an example of a schematic configuration of a rainwater drainage system according to the fourth embodiment. Fig. 8 is a vertical cross-sectional view for explaining an example of a schematic configuration of a siphon-type drainage member applied to the rainwater drainage system according to the fourth embodiment, and Fig. 9 is a perspective view.

In Figures 7 to 9, reference numeral 10A denotes a building, reference numeral 100A denotes a rainwater drainage system (rainwater drainage piping structure), reference numeral 110 denotes a siphon-type drainage member, reference numeral 120 denotes the rainwater piping body, reference numeral 121 denotes a horizontal pipe, reference numeral 122 denotes a main pipe, reference numeral 123 denotes a first vertical pipe, reference numeral 125 denotes a curing pipe (second vertical pipe), and reference numeral 150 denotes a branch pipe.

As shown in FIG. 7, the rainwater drainage system (rainwater drainage piping structure) 100A is applied to, for example, an eight-story building 10A (for example, 24 m high).
The building 10A can be applied to, for example, a factory or shopping center that is 20 m or more in height.

The rainwater drainage system 100A further includes, for example, a siphon-type drainage member 110, a rainwater piping main body 120 that drains rainwater flowing in from the siphon-type drainage member 110 toward the lower floors, and a branch pipe 150 connected to the rainwater piping main body 120 at a junction 120T on an intermediate floor.
The storm water drainage system 100A is configured to drain the drainage water flowing down from the upper floors and the drainage water combined with the branch pipe 150 into a storm water inlet 160 (see the first embodiment) buried underground.

As shown in Figures 8 and 9, the siphon-type drainage member 110 includes, for example, a base plate portion 111 formed in a substantially circular shape with a circular through hole 110H formed in the center, a plurality of vertical ribs 112 formed integrally with the upper surface of the base plate portion 111, rising upward, and spaced apart in the circumferential direction, and a tubular portion 113 extending downward from the periphery of the through hole 110H.

The base plate portion 111, the vertical ribs 112, and the cylindrical portion 113 are integrally formed by casting a metal material such as an aluminum alloy, cast iron, or stainless steel.
In addition, the siphon-type drainage member 110 is arranged (e.g., buried) on the upper surface of the roof slab 15, for example.

The vertical rib 112 is formed, for example, in a substantially U-shape in plan view, with the bottom portion (the folded curved portion) of the U-shape being disposed on the side of the through hole 111H.
In addition, the vertical rib 112 is formed, for example, as a pair of opposing raised wall portions formed from the bottom of the U-shape toward the opening side, extending radially outward from the center of the flow hole 111H, and the spacing between them becomes wider as they extend radially outward.

The lower end of the tubular portion 113 is disposed within a through hole 15H formed in the roof slab 15, and is connected to a connecting short pipe 121A by a connecting member 121B.
The cylindrical portion 113 is connected to a horizontal pipe 121 via a connecting short pipe 121A and a T-shaped joint 121T, and is configured to drain rainwater flowing into the siphon-type drainage member 110 into the horizontal pipe 121.

In addition, the siphon-type drainage member 110 suppresses the formation of an air column near the center of the rainwater (drainage) that flows into the tube portion 113 due to the siphon effect, thereby allowing the rainwater to flow efficiently toward the floor below.
The configuration of the siphon-type drainage member 110 is merely an example, and the configuration can be set arbitrarily.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
In the examples, the comparative example and invention examples 1 to 5 were used to carry out the following verification tests 1 and 2 to confirm the effects of the storm water drainage system.

In the examples, a storm water drainage system (storm water drainage piping structure) shown in Fig. 10 and Fig. 11 was used. Fig. 10 is a conceptual diagram for explaining the schematic configuration of the storm water drainage system used in the examples, and Fig. 11 is a conceptual diagram for explaining the specific configuration of the storm water drainage system in the examples.
The rainwater drainage system (rainwater drainage piping structure) is composed of piping made of transparent resin material.
As shown in FIG. 10, the storm water drainage system is installed in an eight-story experimental facility (building).

The experimental facility (building) has a first floor height of 3.0 m from ground level (GL) up to the second floor, and the heights of the second to eighth floors are each set to 2.8 m.
In addition, the siphon-type drainage member is installed 1.0 m above the floor surface of the 8th floor.
In addition, in the storm water drainage system, a pressure sensor for measuring the pressure inside the main pipe (vertical piping) was installed at the pressure measurement position shown in Fig. 10 of the main pipe. Also, as shown in Fig. 10, an expansion joint was placed midway along the main pipe.

Comparative Example
In the comparative example, as shown in FIG. 11, a junction was provided by connecting a branch pipe to a main pipe at a midpoint in the height direction, where the flow passage area in the vertical direction does not change.
Main pipe: Nominal diameter 100A
Branch pipe: 90° Y pipe with nominal diameter of 100A Junction: GL+6.5m (3rd floor floor surface +1700mm)

[Example 1 of the present invention]
Example 1 of the present invention corresponds to the first embodiment, and uses a first vertical pipe arranged on the upper side and a curing pipe (second vertical pipe) arranged below the first vertical pipe, and constructs a main pipe by inserting the lower part of the first vertical pipe into the curing pipe.
Then, a branch pipe was connected to the first vertical pipe above the upper end opening of the curing pipe (second vertical pipe) to provide a junction.
First vertical pipe: nominal diameter 100A
Curing pipe (second vertical pipe): nominal diameter 125A
Curing pipe (second vertical pipe): nominal diameter 125A
Height of the connection between the first vertical pipe and the curing pipe (second vertical pipe): GL+1000m
Branch pipe: 90° Y pipe with nominal diameter of 100A. A gap was provided between the first vertical pipe and the curing pipe (second vertical pipe).
Junction: GL+5.5m (3rd floor floor surface+700mm)

[Example 2 of the present invention]
Inventive example 2 corresponds to the first embodiment and has the same configuration as in Inventive example 1. Specifically, it differs from Inventive example 1 in the height of the joining portion.
First vertical pipe: nominal diameter 100A
Curing pipe (second vertical pipe): nominal diameter 125A
Height of the connection between the first vertical pipe and the curing pipe (second vertical pipe): GL+1000m
Branch pipe: 90° Y pipe with nominal diameter of 100A. A gap was provided between the first vertical pipe and the curing pipe (second vertical pipe).
Junction: GL+1.86m (2nd floor surface +860mm)

[Example 3 of the present invention]
In Example 3 of the present invention, which corresponds to the second embodiment, a main pipe is formed by connecting a first vertical pipe arranged on the upper side and a second vertical pipe arranged below the first vertical pipe with an increaser. A branch pipe is connected to the first vertical pipe above the second vertical pipe to provide a junction.
First vertical pipe: nominal diameter 100A
Second vertical pipe: Nominal diameter 125A
Branch pipe: 90° Y pipe with nominal diameter of 100A Increaser height: GL+450mm
Branch pipe: 90° Y pipe with nominal diameter of 100A Junction: GL+2.86m (2nd floor surface +1860mm)

[Example 4 of the present invention]
Example 4 of the present invention corresponds to the second embodiment, and has the same configuration as Example 3 of the present invention. Specifically, Example 4 of the present invention is different from Example 3 of the present invention in the connection joint used at the junction.
First vertical pipe: nominal diameter 100A
Second vertical pipe: Nominal diameter 125A
Branch pipe: 90° Y pipe with nominal diameter of 100A Increaser height: GL+450mm
Branch pipe: 45° Y pipe with nominal diameter of 100A Junction: GL+2.86m (2nd floor surface +1860mm)

[Example 5 of the present invention]
In Example 5 of the present invention, which corresponds to the third embodiment, a main pipe is formed by connecting a first vertical pipe arranged on the upper side and a second vertical pipe arranged below the first vertical pipe with an increaser. A branch pipe is connected to the second vertical pipe midway through the second vertical pipe to provide a junction.
First vertical pipe: nominal diameter 100A
Second vertical pipe: Nominal diameter 125A
Increaser height: GL+450mm
Branch pipe: Large bend 90° Y pipe (LT pipe) with nominal diameter of 100A
Junction: GL+2.86m (2nd floor surface +1860mm)

(1) Verification test 1
The verification results of verification test 1 in the embodiment will be described below with reference to FIG.
FIG. 12 is a pressure distribution diagram illustrating the internal pressure of the main pipe of the storm water drainage system related to Verification Test 1 in the examples.
Using the comparative example and invention examples 1 to 3, rainwater was supplied from the siphon-type drainage member through a horizontal pipe to the main pipe to verify the change in the internal pressure of the main pipe.

In verification test 1, as shown in Figure 12, in both the comparative example and invention examples 1 to 3, the pressure inside the pipe of the drainage water supplied from the siphon drainage member was negative pressure on the upper floors (for example, approximately 60 kPa on the floor surface of the 8th floor), and no significant difference was observed.
However, in the comparative example, the pipe pressure increases linearly as one descends to lower floors, becomes zero near the third floor surface (GL + approximately 6 m), and increases to positive pressure on the first and second floors.

On the other hand, in Examples 1 to 3 of the present invention, as shown in Figure 12, the pipe pressure increases to the same extent as the comparative example on floors above the fifth floor, but the increase in pipe pressure is slower on floors below the fifth floor compared to the comparative example.
It was also confirmed that in Examples 1 to 3 of the present invention, the pressure inside the main pipe remained negative even when the temperature dropped to the second floor.
Therefore, in Examples 1 to 3 of the present invention, it is possible to stably merge the drainage water from the branch pipe into the main pipe.

(2) Verification test 2
The verification results of Verification Test 2 in the working example will be described below with reference to FIG.
Fig. 13 is a diagram illustrating the confluence flow rate of the branch pipes of the storm water drainage system in the verification test 2 in the embodiment. In Fig. 13, ◯ indicates that the flows can be smoothly confluent, and ■ △ indicates that the flows can be confluent although backflow occurs occasionally.
Verification test 2 was performed using Examples 3 to 5 of the present invention, in which rainwater was supplied from the siphon-type drainage member through a horizontal pipe to the main pipe, and wastewater was merged from the branch pipe into the main pipe while changing the flow rate. The merging state of the wastewater at the junction was visually observed to verify the wastewater flow rate that could be merged from the branch pipe into the main pipe.
The flow rate of rainwater flowing from the siphon-type drainage member to the main pipe was 40 L/S.

In the verification test 2, as shown in FIG. 13, when the drainage flow rate from the branch pipe was 1 L/S to 2 L/S, all of the invention examples 3 to 5 stably merged into the main pipe.
On the other hand, in the third example of the present invention, as shown in FIG. 13, when the drainage flow rate from the branch pipe is 3 L/S, it becomes more difficult for the drainage flows to merge compared to when it is 1 L/S to 2 L/S.
Moreover, in Example 4 of the present invention, even when the drainage flow rate from the branch pipe is 5 L/S, the drainage can be stably merged into the main pipe.
Moreover, in Example 5 of the present invention, it can be said that the wastewater can stably merge into the main pipe even when the wastewater flow rate from the branch pipe is 10 L/S.
As described above, it was confirmed that invention examples 4 and 5 are more advantageous than invention example 3 in that the drainage flow rate that can be joined from the branch pipe is large.

The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the invention.

In the above embodiment, in the storm water drainage system (storm water drainage piping structure) 100, 200, 300, the first vertical pipe 123, 223, 323 is formed with a nominal diameter of 100A, the protective pipe 125 and the second vertical pipe 225, 325 are formed with a nominal diameter of 125A, and the first vertical pipe is formed with a nominal diameter one size larger than the protective pipe and the second vertical pipe. However, the flow path cross-sectional area or nominal diameter of the first vertical pipe 123, 223, 323, the protective pipe 125, and the second vertical pipe 225, 325 can be set arbitrarily.

For example, the flow path area of the protective pipe 125 and the second vertical pipes 225, 325 may be set to a flow path area difference that is less than one size larger than the flow path area of the first vertical pipes 123, 223, 323, or may be set to a flow path area difference that is more than one size larger.
In addition, the nominal diameters of the protective pipe 125 and the second vertical pipes 225 and 325 may be set to be larger than the flow path area of the first vertical pipe 123 by an area difference of less than one size in nominal diameter, or may be set to an area difference of more than one size.

In the above embodiment, for example, the upper opening of the curing pipe 125 in the storm water drainage system 100 is described as being formed at a height of 2 m or less from the ground, but the height at which the upper opening of the curing pipe 125 is formed can be set arbitrarily, and may be formed at a height higher than 2 m, for example.

In addition, in the above embodiment, the increasers 222S, 322S are described as being located 10 m or less above ground level and on the third or lower floor of the building 10, but the height position at which the increasers 222S, 322S are located can be set arbitrarily.

In addition, in the above embodiment, the junctions 120T, 220T, and 320T are described as being formed on the third floor or lower or at a height of 10 m or lower. However, for example, the junctions 120T, 220T, and 320T may be formed on a floor higher than the third floor or at a height of more than 10 m.

In the above embodiment, the junction where the branch pipes 150, 150A join the main pipes 122, 222, 322 is configured with a tee (90° Y-shaped pipe), but various joints, such as a 45° Y-shaped pipe or a large bend 90° Y-shaped pipe (LT pipe), may be used without being limited to a tee.

In the above embodiment, the increaser 222S, 322S is used to expand the diameter from the first vertical pipe 223, 323 to the second vertical pipe 225, 325. However, various types of expansion joints may be used, or the diameter may be expanded using a Y-shaped pipe such as a T-shaped pipe with a small diameter on the upper side (one end) and a large diameter on the lower side (the other end).

In addition, in the above embodiment, the siphon-type drainage member 110 is described as being installed on the rooftop, but it is not limited to being installed on the rooftop, and may be installed on a roof, balcony, etc., for example.

In addition, the components in the above embodiments may be replaced with known components as appropriate without departing from the spirit of the present invention, and the above embodiments may be combined as appropriate.

10, 10A Building 100, 100A, 200, 300 Rainwater drainage system (rainwater drainage piping structure)
20, 110 Siphon type drainage member 120, 220, 320 Rainwater pipe body 120T, 220T, 320T Junction 121 Horizontal pipe 122, 222, 322 Main pipe 123, 223, 323 First vertical pipe 125 Curing pipe (second vertical pipe)
150, 150A Branch pipe 160 Storm water inlet 222S, 322S Increaser 225, 325 Second vertical pipe

Claims (4)

A rainwater drainage piping structure that is arranged in a building and drains rainwater,
A siphon type drainage member;
A main pipe through which rainwater flowing in from the siphon-type drainage member flows;
a branch pipe connected to a junction located midway in the height direction of the main pipe and allowing wastewater to flow into the junction from the outside;
The main pipe is
A first vertical pipe is disposed on an upper side and connected to the siphon-type drainage member, and a second vertical pipe is disposed on a lower side of the first vertical pipe and has a flow path area larger than that of the first vertical pipe.
Equipped with
The junction is formed in the first vertical pipe,
The second vertical pipe is
A curing pipe located below the junction and arranged at a distance from an outer wall portion of the first vertical piping,
The nominal diameter of the second vertical pipe is
The nominal diameter is set to be one size or more larger than the nominal diameter of the first vertical pipe,
A rainwater drainage piping structure, characterized in that the internal pressure of the pipe at the confluence is negative pressure. A rainwater drainage piping structure that is arranged in a building and drains rainwater,
A siphon type drainage member;
A main pipe through which rainwater flowing in from the siphon-type drainage member flows;
a branch pipe connected to a junction located midway in the height direction of the main pipe and allowing wastewater to flow into the junction from the outside;
The main pipe is
A first vertical pipe is disposed on an upper side and connected to the siphon-type drainage member, and a second vertical pipe is disposed on a lower side of the first vertical pipe and has a flow path area larger than that of the first vertical pipe.
Equipped with
The junction is formed in the first vertical pipe,
The second vertical pipe is
A curing pipe located below the junction and arranged at a distance from an outer wall portion of the first vertical piping,
The lower side of the curing pipe is buried in the ground,
The lower end of the curing pipe is connected to an elbow (excluding those having a straightening section inside) buried in the ground,
A rainwater drainage piping structure, characterized in that the internal pressure of the pipe at the confluence is negative pressure. The rainwater drainage piping structure according to claim 1 or 2,
The confluence portion is
A rainwater drainage piping structure arranged 10 m or less above ground level. The rainwater drainage piping structure according to claim 1 ,
The lower side of the curing pipe is buried in the ground,
A rainwater drainage piping structure characterized in that the lower end of the curing pipe is connected to an elbow buried in the ground.

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