JP7706244B2 - Siphon Drainage System - Google Patents

Description

The present invention relates to a siphon drainage system.

In recent years, so-called siphon drainage systems have been proposed as an alternative to conventional gradient drainage systems (see, for example, Patent Document 1). As described in Patent Document 1, the siphon drainage system is a system that connects a siphon drain pipe to a plumbing fixture and uses the siphon force (negative pressure) generated in the vertical pipe that forms the hanging part of the siphon drain pipe to improve the efficiency of drainage from the plumbing fixture.

In this siphon drainage system, wastewater discharged from plumbing fixtures flows into the siphon drain pipe and fills the horizontal pipe section, which forms the horizontal part of the siphon drain pipe, and the vertical pipe section, which forms the hanging part of the siphon drain pipe. When the vertical pipe section of the siphon drain pipe is filled with wastewater, the wastewater in the vertical pipe section falls due to gravity, and a suction force corresponding to the head difference in the vertical pipe section, i.e., siphon force, is generated inside the vertical pipe section. The wastewater in the horizontal pipe section is sucked toward the vertical pipe section by the siphon force, and flows down the siphon drain pipe as a so-called full flow in which the siphon drain pipe is filled with wastewater.

In this way, in a siphon drainage system, wastewater flows into the vertical pipe section located downstream of the horizontal pipe section, and siphon force is not generated unless the vertical pipe section is filled with wastewater. Therefore, there is a time lag between when wastewater is drained from the plumbing fixtures and when siphon force is generated, and it is desirable to drain the wastewater from the plumbing fixtures quickly.

Here, a siphon drainage system is known that shortens the time it takes to fill the vertical pipe section by making the diameter of the vertical pipe smaller than the diameter of the horizontal pipe (see Patent Document 1).

JP 2017-31670 A

In the above-mentioned siphon drainage system, a vertical pipe is connected to the downstream side of the horizontal pipe via a joint whose diameter gradually decreases and an L-shaped vent pipe (also called a drop pipe), requiring a large number of parts.

The present invention takes into consideration the above-mentioned facts and aims to provide a siphon drainage system that can generate siphon force quickly with a small number of parts.

The siphon drainage system described in claim 1 comprises a horizontal pull pipe that drains drainage from a water-related fixture and extends horizontally, a vertical pipe that is provided downstream of the horizontal pull pipe in the drainage direction and extends downward, and a drop pipe that is provided between the horizontal pull pipe and the vertical pipe and curved downward from the horizontal direction, and the drop pipe has a reduced diameter portion in which the flow path cross-sectional area on the radial inside of the curve is set smaller than the flow path cross-sectional area on the radial outside of the curve, with the central axis of the flow path as the boundary.

In the siphon drainage system described in claim 1, a curved drop pipe provided between the horizontal pipe section and the vertical pipe is provided with a reduced diameter portion in which the flow path cross-sectional area on the radially inner side of the curve is set smaller than the flow path cross-sectional area on the radially outer side of the curve, with the central axis of the flow path as the boundary.
Therefore, when wastewater flows into the drop pipe from the horizontal pipe, the water level rises faster at the inlet side of the drop pipe, i.e., the end side upstream in the drainage direction, and the flow path fills up faster, compared to a drop pipe in which the flow path cross-sectional area on the radially inner side of the curve is set to be the same as the flow path cross-sectional area on the radially outer side of the curve, in other words, a drop pipe with a normal flow path with a perfectly circular cross section. As a result, the vertical pipe following the drop pipe also fills up faster, making it possible to shorten the start-up time of the siphon.

In addition, the siphon drainage system described in claim 1 does not require a joint whose diameter gradually decreases downstream of the horizontal pipe, as in the siphon drainage system of the conventional technology, so the number of system parts can be reduced compared to the siphon drainage system of the conventional technology.
The "radially inner side of the curvature" can be rephrased as "the side closer to the center of curvature of the curvature" and the "radially outer side of the curvature" can be rephrased as "the side farther from the center of curvature of the curvature".

The invention described in claim 2 is the siphon drainage system described in claim 1, in which the flow path cross-sectional area of the reduced diameter portion is set to be smaller than the flow path cross-sectional area of the horizontal pipe.

In the siphon drainage system described in claim 2, the cross-sectional area of the flow path of the drop pipe is set smaller than the cross-sectional area of the flow path of the horizontal pipe, making it possible to fill the drop pipe even more quickly.

The invention described in claim 3 is a siphon drainage system described in claim 1 or claim 2, in which the reduced diameter portion, when viewed in a cross section perpendicular to the flow path, includes a pair of inclined surfaces that approach each other toward the radial inside of the curve, and a connecting surface that connects the end of one of the inclined surfaces to the end of the other inclined surface, and the inner wall of the pipe on the radial outside of the curve, which is bounded by the central axis of the flow path, includes an arc surface with the central axis as the center of curvature.

In the reduced diameter portion of the drop pipe of the siphon drainage system described in claim 3, when viewed in a cross section perpendicular to the flow path, the inner wall of the pipe on the radially inner side of the curve, with the central axis of the flow path as the boundary, is configured to include a pair of inclined surfaces that approach each other toward the radially inner side of the curve and a connecting surface that connects the end of one inclined surface to the end of the other inclined surface, and the inner wall of the pipe on the radially outer side of the curve, with the central axis as the boundary, is configured to include an arc surface with the central axis as the center of curvature. With this simple configuration, the flow path cross-sectional area on the radially inner side of the curve can be made smaller than the flow path cross-sectional area on the radially outer side of the curve.

In addition, if a pair of inclined surfaces approaching each other toward the radially inner side of the curve are provided on the inner wall of the drop pipe on the radially inner side of the curve, when the end of one inclined surface and the end of the other inclined surface are connected to each other, the connection part will have a V-shaped, pointed valley bottom, making it easy for foreign matter to accumulate in the valley bottom during drainage.

In the reduced diameter portion of the drop pipe described in claim 3, the end of one of the pair of inclined surfaces is connected to the end of the other inclined surface by a connecting surface, and the end of one inclined surface is separated from the end of the other inclined surface. In other words, the bottom of the valley formed by the pair of inclined surfaces is wide and not sharp, so that foreign matter during drainage is less likely to accumulate at the bottom of the valley, and even if foreign matter does become trapped at the bottom of the valley, it is easily washed away and removed by the force of the next drainage.

The invention described in claim 4 is a siphon drainage system described in claim 3, in which, when the reduced diameter portion is viewed in a cross section perpendicular to the flow path, the pair of inclined surfaces are each linear, and the inclined surfaces are inclined at an angle of more than 30° and not more than 45° with respect to an imaginary horizontal line that passes through the middle of the pair of inclined surfaces and is perpendicular to an imaginary vertical center line that passes through the central axis of the flow path.

The start-up time of the siphon can be shortened by making the shape of the inclined surface of the reduced diameter portion of the drop pipe linear when viewed in a cross section perpendicular to the flow path, and by inclining the inclined surface at an angle of more than 30° and not more than 45° with respect to an imaginary horizontal line that passes through the middle of the pair of inclined surfaces and is perpendicular to an imaginary vertical center line that passes through the central axis of the flow path. Note that if the inclination angle of the inclined surface is 30° or less, it may be impossible to form a connecting surface.
In addition, "more than 30° and 45° or less with respect to an imaginary horizontal line perpendicular to an imaginary vertical center line passing through the central axis of the flow path" can be rephrased as "45° or more and less than 60° with respect to the imaginary vertical center line."

As described above, the siphon drainage system of the present invention has the excellent effect of being able to generate siphon force quickly with a small number of parts.

1 is a schematic diagram showing the overall configuration of a siphon drainage system according to an embodiment of the present invention. FIG. FIG. 2 is a cross-sectional view taken along the central axis of the flow path, showing the inside of the drop pipe. FIG. 3 is a front view of the drop pipe shown in FIG. 2 as viewed from the horizontal pipe side connection portion side. FIG. 3 is a bottom view of the drop pipe shown in FIG. 2 as viewed from the upright pipe side connection portion side. 5 is a cross-sectional view perpendicular to the central axis of the drop pipe shown in FIG. 2 (cross-sectional view taken along line 5-5 in FIG. 2). 6A and 6B are cross-sectional views showing the end of the inclined surface (cross-sectional views taken along line 6-6 in FIG. 3). 13 is a table showing a simulation result. 11A to 11C are cross-sectional views showing drop pipes according to modified examples.

A siphon drainage system 10 according to one embodiment of the present invention will be described with reference to FIGS.
In each drawing, the directions indicated by the arrows X and Y are directions along a horizontal plane and are perpendicular to each other. The direction indicated by the arrow Z is a direction along the vertical direction (up and down direction). The directions indicated by the arrows X, Y, and Z in each drawing are assumed to be mutually consistent.

<Siphon drainage system>
1 is a schematic diagram showing the overall configuration of a siphon drainage system 10 according to this embodiment. The siphon drainage system 10 according to this embodiment is a drainage system that efficiently discharges wastewater from a plumbing fixture 20 by utilizing siphon force.

The siphon drainage system 10 is used in multi-story apartment buildings and is equipped with a standpipe 12 that directs drainage downward. This standpipe 12 extends vertically through the apartment building and penetrates the slabs 14 of each floor of the apartment building.

The standpipe 12 is disposed inside the building in a pipe space that penetrates the slab 14 and spans multiple floors. Alternatively, the standpipe 12 may be disposed outside the exterior wall 16 that separates the inside and outside of the building, for example, inside a meter box. The siphon drainage system 10 of this embodiment is suitable for use in apartment buildings, but can also be used in various other buildings such as detached houses, office buildings, commercial buildings, and factories.

A plumbing fixture 20 is provided in each unit on each floor of the apartment building. One example of the plumbing fixture 20 is a kitchen sink, with a garbage disposer 22 and a drain trap 24 connected downstream in the drain direction. An L-shaped piping member 26 bent into an L shape is disposed downstream in the drain direction of the drain trap 24. The L-shaped piping member 26 includes a vertical portion 26A connected to the drain trap 24 and extending vertically, a horizontal portion 26B disposed horizontally on the slab 14 and extending horizontally, and a curved portion 26C connecting the vertical portion 26A and the horizontal portion 26B. The plumbing fixture 20 may be another drainage system such as a bathtub, a washbasin, or a washing machine.

Downstream in the drainage direction of the L-shaped piping member 26 is a horizontal pipe member 28 that is disposed on the slab 14 and extends horizontally, in other words, perpendicular to the vertical direction. The L-shaped piping member 26 and the horizontal pipe member 28 are connected via a joint 30.

A curved drop pipe 32 is connected to the downstream end of the horizontal pull pipe member 28 in the drainage direction via a joint 34. A vertical pipe member 36 extending downward is connected to the downstream side of the drop pipe 32 via a joint 38. The downstream side of the drop pipe 32 is inserted into a through hole 14A formed in the slab 14.

The downstream end of the vertical pipe member 36 in the discharge direction is connected to a junction joint 40 attached to the middle part of the vertical pipe 12 via a joint 42.

In this embodiment, the piping portion arranged horizontally on the slab 14, specifically the horizontal section 26B of the L-shaped piping member 26 and the horizontal pipe member 28, are the horizontal pipe 46 of the siphon drain pipe 44. From the viewpoint of ensuring drainage performance, the horizontal pipe 46 may be provided with a water gradient that slopes downward from the joint 30 toward the joint 34. In this embodiment, "horizontal" includes a slope of about the water gradient.
In this embodiment, the downwardly extending upright pipe member 36 serves as a upright pipe 48 of a siphon drain pipe 44 .

<Drop-in pipe>
2, the drop pipe 32, which is an example of the drop pipe of the present invention, is curved in a substantially arc shape in a side view. The drop pipe 32 is formed of a synthetic resin such as rigid PVC, for example.

As shown in Figures 2 to 4, the drop pipe 32 has a straight horizontal pipe side connection portion 32A for connecting the joint 34 to the horizontal pipe member 28 side, and a straight vertical pipe side connection portion 32B for connecting the joint 38 to the vertical pipe member 36 side, and has an arc portion 32C between the horizontal pipe side connection portion 32A and the vertical pipe side connection portion 32B.

As an example, the horizontal pipe side connection part 32A and the joint 34 are connected detachably by screwing. Also, as an example, the vertical pipe side connection part 32B and the joint 38 are connected detachably by screwing.

As shown in Fig. 2, the drop pipe 32 of this embodiment is basically a curved circular pipe, but as shown in Fig. 5(A), a pair of inclined surfaces 50 are formed on the inner wall surface of the pipe at a circumferential interval on the inside of the radius of curvature of the curve when viewed from the side (the side indicated by the arrow R _IN ). The pair of inclined surfaces 50 are formed from the end on the side of the horizontal pulling pipe member 28 toward the side of the vertical pipe member 36, as shown in Fig. 2. In the drop pipe 32 of this embodiment, the portion where the inclined surfaces 50 are formed corresponds to the reduced diameter portion of the present invention.

In the present embodiment, the drop pipe 32 has a pair of inclined surfaces 50 formed on the inner wall surface of the horizontal pipe side connection portion 32A and the inner wall surface of the arc portion 32C, but not on the vertical pipe side connection portion 32B. However, the pair of inclined surfaces 50 may also be formed on the vertical pipe side connection portion 32B.

In the drop pipe 32, a pair of inclined surfaces 50 are formed to protrude radially inward from the inner wall surface of the circular pipe, and a connecting surface 52 is provided between the end of one inclined surface 50 and the end of the other inclined surface 50. Note that, as in the drop pipe 32 shown in FIG. 5(B), there may be no connecting surface 52, and the end of one inclined surface 50 and the end of the other inclined surface 50 that are close to each other may be connected.

As shown in FIG. 5(A), in the drop pipe 32 of this embodiment, the inner wall surface of the portion where the inclined surface 50 is not formed (the connecting surface 52 and the inner wall surface of the vertical pipe side connection portion 32B) is an arc surface with the center of curvature being the central axis 32CL when viewed in a cross section perpendicular to the central axis 32CL of the drop pipe 32, and the radius of curvature of the arc surface is 1/2 the inner diameter D of the portion of the drop pipe 32 where the inclined surface 50 is not formed.

In addition, in this embodiment, the inner diameter D of the portion of the drop pipe 32 where the inclined surface 50 is not formed is the same as the inner diameter of the horizontal pull pipe member 28 connected to the upstream side in the drainage direction.

The drop-in pipe 32 has a pair of inclined surfaces 50 protruding from the inner wall surface on the radially inner side of the curved portion at the central axis 32CL of the flow passage, so that the flow passage cross-sectional area A (diagonal line slanting upwards to the left) on the radially inner side (arrow R _IN ) of the curved portion at the central axis 32CL of the flow passage is smaller than the flow passage cross-sectional area B (diagonal line slanting upwards to the right) on the radially outer side (arrow R _OUT ) of the curved portion. Therefore, the cross-sectional area of the flow passage through which the wastewater flows decreases when it flows from the horizontal pull pipe member 28 into the drop-in pipe 32.

In addition, in the drop pipe 32, the flow path cross-sectional area (flow path cross-sectional area A+B) of the portion where the inclined surface 50 is formed is preferably set within the range of 70 to 80% of the flow path cross-sectional area of the horizontal pull pipe member 28, as an example.

As shown in FIG. 5A, the inclined surfaces 50 of this embodiment are formed linearly when viewed in a cross section perpendicular to the flow path. They are inclined at an inclination angle θ with respect to a virtual horizontal line FHL that passes through the center of the pair of inclined surfaces 50 and is perpendicular to a virtual vertical center line FVCL that passes through the central axis 32CL. As an example, it is preferable to set this inclination angle θ to be greater than 30° and equal to or less than 45° when the flow path cross-sectional area (flow path cross-sectional area A+B) of the portion where the inclined surfaces 50 are formed is set to 75% of the flow path cross-sectional area of the horizontal pipe member 28.

It is preferable that the inclined surface 50 has a chamfered radius 50A as shown in FIG. 6(A) or a tapered surface 50B as shown in FIG. 6(B) at the end on the side of the horizontal pipe member 28 into which the wastewater flows in, so that the wastewater can flow smoothly into the drop pipe 32.

(Action and Effects)
In the siphon drainage system 10 according to an embodiment of the present invention, when wastewater is discharged from the plumbing fixture 20, the wastewater flows into the drop pipe 32 via the disposer 22, the drain trap 24, the L-shaped piping member 26, and the horizontal pull-out pipe member 28.

Here, in the portion of the drop pipe 32 where the inclined surface 50 is formed, the flow passage cross-sectional area A on the radially inner side of the curve is set smaller than the flow passage cross-sectional area B on the radially outer side of the curve, with the central axis 32CL of the flow passage as the boundary, and the flow passage cross-sectional area (flow passage cross-sectional area A + B) of the portion where the inclined surface 50 is formed is set smaller than the flow passage cross-sectional area of the horizontal pull pipe member 28.

Therefore, when wastewater flows into the drop pipe 32 of this embodiment, the water level rises faster at the inlet side, in other words, at the end side upstream in the drainage direction (the side of the horizontal pull pipe side connection part 32A), compared to a drop pipe having a normal flow path (inner diameter D) with a perfectly circular cross-sectional shape, and the inside of the flow path of the drop pipe 32 fills up quickly. Therefore, the vertical pipe 48 following the drop pipe 32 also fills up quickly, making it possible to shorten the start-up time of the siphon.

In the siphon drainage system 10 according to this embodiment, the siphon can be quickly started with a simple configuration in which the shape of the inner wall surface of the drop pipe 32 is changed as described above. Also, unlike the siphon drainage system of the prior art, a joint with a gradually decreasing diameter is not required on the downstream side of the horizontal pipe, so the number of parts can be reduced compared to the siphon drainage system of the prior art.

In addition, if the difference between the flow path cross-sectional area (flow path cross-sectional area A+B) of the portion of the drop pipe 32 where the inclined surface 50 is formed and the flow path cross-sectional area of the horizontal pipe member 28 is too small, the siphon start-up time cannot be shortened, so it is preferable that the flow path cross-sectional area (flow path cross-sectional area A+B) of the portion where the inclined surface 50 is formed be 80% or less of the flow path cross-sectional area of the horizontal pipe member 28.

In addition, if the difference between the flow path cross-sectional area (flow path cross-sectional area A+B) of the portion where the inclined surface 50 is formed and the flow path cross-sectional area of the horizontal pipe member 28 is too large, the flow path area of the drop pipe 32 becomes too small relative to the horizontal pipe member 28, and even if a siphon force is generated, the drainage capacity (amount of drainage per unit time) decreases. As a result, it becomes impossible to shorten the siphon start-up time, so it is preferable to set the flow path cross-sectional area (flow path cross-sectional area A+B) of the portion where the inclined surface 50 is formed to 70% or more of the flow path cross-sectional area of the horizontal pipe member 28.

As shown in Figures 3 to 5 (A), in the drop pipe 32 of this embodiment, a connecting surface 52 is provided between one inclined surface 50 and the other inclined surface 50, making the bottom of the valley wider, so that foreign matter during drainage is less likely to accumulate in the bottom of the valley. Even if foreign matter does become trapped in the bottom of the valley, it will be washed away by the force of the next drainage and will be easily removed.

If foreign matter during drainage does not accumulate in the valley bottom between one inclined surface 50 and the other inclined surface 50, it is not necessary to provide a connecting surface 52 between one inclined surface 50 and the other inclined surface 50, as shown in Figure 5 (B).

As an example, it is preferable to set the inclination angle θ of the inclined surface 50 to more than 30° and less than 45° when the flow path cross-sectional area (flow path cross-sectional area A+B) of the portion where the inclined surface 50 is formed is set to 75% of the flow path cross-sectional area of the horizontal pipe member 28. The reason for setting the inclination angle θ of the inclined surface 50 to an angle greater than 30° is that if the inclination angle θ is less than 30°, one inclined surface 50 and the other inclined surface 50 will be connected, and the valley bottom will become sharp and narrow. On the other hand, the reason for setting the inclination angle θ to 45° or less is that if the inclination angle θ exceeds 45°, it will not be possible to speed up the start-up time of the siphon.

(Test Example)
Table 1 in Figure 7 shows the cross-sectional shape of the flow path of the drop-in pipe when the flow path cross-sectional area of the portion of the drop-in pipe where the inclined surface is formed is set to 75% of the flow path cross-sectional area of the horizontal pipe member and the inclination angle θ of the inclined surface is changed.
As shown in Table 1, if the inclination angle θ of the inclined surface is 31° or more, it is possible to provide a connecting surface 52 between one inclined surface and the other inclined surface. However, if the inclination angle θ is 30°, the one inclined surface and the other inclined surface are connected to each other, and it is no longer possible to provide the connecting surface 52.

In addition, the inclination angle θ of the inclined surface of the drop pipe was changed in various ways, and the time from when the wastewater started to flow until the water was full was obtained by simulation at each part of the vertical pipe side of the drop pipe and the inclination angle θ. The full water was measured at three points: 63 mm, 100 mm, and 150 mm downward from the central axis of the inlet of the drop pipe.
As a result of the simulation, it was found that when the inclination angle θ is within the range of 31° to 45°, the time until the vertical pipe becomes full is shorter than in other cases. This shows that by setting the inclination angle θ of the inclined surface within the range of 31° to 45°, it is possible to suppress the accumulation of foreign matter and to speed up the start of the siphon.

[Other embodiments]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms without departing from the spirit and scope of the present invention.

In the drop pipe 32 of the above embodiment, the inclined surface 50 has a straight shape when viewed in cross section, but as shown in FIGS. 8(A) and 8(B), the inclined surface 50 may have a curved shape when viewed in cross section.
In addition, in the drop pipe 32 of the above embodiment, when viewed in cross section, inclined surfaces 50 are formed on both sides of the central axis 32CL, but as shown in Figure 8 (C), the inclined surface 50 may be provided on only one side of the central axis 32CL.

In the above embodiment of the drop pipe 32, the inclined surface 50 is provided from the upstream end to the downstream end of the arc section 32C (or the downstream end of the vertical pipe side connection section 32B), but if it is provided in a part of the drop pipe 32 (as an example, from the longitudinal middle part of the arc section 32C to the downstream side), it is possible to speed up the start of the siphon. In other words, the part where the inclined surface 50 is formed may be anywhere on the drop pipe 32, as long as the start-up time of the siphon can be shortened.

10...Siphon drainage system, 20...Water -related equipment, 32...Drop-in pipe, 46...Horizontal pipe, 48...Vertical pipe, A...Flow path cross-sectional area on the radially inner side of the curve, B...Flow path cross-sectional area on the radially outer side of the curve, 50...Inclined surface (reduced diameter portion), 52...Connecting surface

Claims (4)

A horizontal pipe that drains drainage from the water-related equipment and extends horizontally;
A vertical pipe provided downstream of the horizontal pipe section in the drainage direction and extending downward;
A drop pipe is provided between the horizontal pipe section and the vertical pipe, the drop pipe being downstream of the horizontal pipe section and upstream of the vertical pipe, and curved downward from the horizontal direction;
Equipped with
The drop pipe has a reduced diameter portion in which a flow passage cross-sectional area on a radially inner side of the curve is set smaller than a flow passage cross-sectional area on a radially outer side of the curve, with the central axis of the flow passage as a boundary.
Siphon drainage system. The flow path cross-sectional area of the reduced diameter portion is set to be smaller than the flow path cross-sectional area of the horizontal drawing pipe.
2. The siphon drainage system of claim 1. When viewed in a cross section perpendicular to the flow path, the reduced diameter portion is configured such that the inner wall of the pipe on the radially inner side of the curve, with the central axis of the flow path as a boundary, includes a pair of inclined sides approaching each other toward the radially inner side of the curve , and a connecting side connecting an end of one of the inclined sides to an end of the other inclined side, and the inner wall of the pipe on the radially outer side of the curve, with the central axis as a boundary, includes an arc surface having a center of curvature at the central axis.
The siphon drainage system according to claim 1 or 2. When the reduced diameter portion is viewed in a cross section perpendicular to the flow path, the pair of inclined sides are each straight,
The inclined side is inclined at an inclination angle of more than 30° and not more than 45° with respect to a virtual horizontal line that passes through a center portion of the pair of inclined sides and is perpendicular to a virtual vertical center line that passes through a central axis of the flow path.
4. The siphon drainage system of claim 3.