Drain pipeline structure

Abstract

To provide a drain pipeline structure which enables improvement of flexibility of arrangement of an air conditioner and easy construction of a pipeline.SOLUTION: A drain pipeline structure 1 includes: a siphon drain lateral pipe 350 communicating with an air conditioner 215; an elbow joint 400 provided at a side opposite to the air conditioner 215 of the siphon drain lateral pipe 350; a siphon drain vertical pipe 440 extending downward from the elbow joint 400; drain vertical main pipes 80(a), 80(b); and a confluence joint 11 which joins a side opposite to the elbow joint 400 of the siphon drain vertical pipe 440 to the drain vertical main pipes 80(a), 80(b). The confluence joint 11 and the siphon drain vertical pipe 440 are disposed between a ceiling slab 201(a) and a floor slab 201(b) which define a room R in which the air conditioner 215 is disposed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a drain piping structure. [Background technology]

[0002] Some drain pipes have a heat insulating material wrapped around the outer surface of a typical pipe. When using such drain pipes, the installation of the heat insulating material is necessary, which is cumbersome. Therefore, a multi-layer pipe is known in which a foamed layer for heat insulation is integrally provided on the outer surface of the pipe (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-143730 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional drain piping for air conditioning uses gravity to drain water, requiring a drainage slope, which can cause the pipe to come into contact with the ceiling depending on the location of the air conditioner, limiting the distance from the vertical main pipe that drains water from each floor to the air conditioner.If a foam layer is provided, as in the multi-layer pipe described in Patent Document 1, and the foam layer is made thicker to improve insulation, increasing the outer diameter, further limiting the distance from the vertical main pipe to the air conditioner. In addition, obstacles such as beams and other pipes are installed above the ceiling slab, so the drain pipes must be installed in a way that avoids these obstacles while maintaining a drainage slope. This also limits the freedom in arranging the air conditioner and makes piping installation complicated.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a drain piping structure that allows for greater freedom in the placement of air conditioners and makes piping installation easier. [Means for solving the problem]

[0006] The present invention has the following aspects. (1) One aspect of the drain piping structure of the present invention comprises a horizontal siphon drain pipe communicating with an air conditioner, an elbow joint provided on the side of the horizontal siphon drain pipe opposite the air conditioner, a vertical siphon drain pipe extending downward from the elbow joint, a main vertical drain pipe, and a junction joint that joins the side of the vertical siphon drain pipe opposite the elbow joint with the main vertical drain pipe, and the junction joint and the vertical siphon drain pipe are arranged between a ceiling slab and a floor slab that define a room in which the air conditioner is located.

[0007] The drain piping structure described above allows drainage water from the air conditioner to flow through the horizontal siphon drain pipe, elbow joint, vertical siphon drain pipe, and junction joint via the siphon phenomenon, using negative pressure from the drainage water flowing from the upper floors in the vertical main drain pipe. This eliminates the need for a drainage gradient, which is required when draining water by gravity. This essentially eliminates any limitations on the distance from the vertical main pipe to the air conditioner. Furthermore, because a drainage gradient is not necessarily required, even if the drainage water needs to be installed to avoid obstacles, this minimizes the reduction in flexibility in the placement of the air conditioner and simplifies piping installation. In addition, because the junction joint and siphon drain vertical pipe are located between the ceiling slab and floor slab that define the room where the air conditioner is installed, there is no need for the siphon drain vertical pipe to penetrate the slab, and there are no restrictions on the construction of slab penetrations. This makes construction and installation easier, and it can also be installed during renovations.

[0008] (2) In the above aspect (1), a storage tank may be provided between the air conditioner and the horizontal siphon drain pipe.

[0009] In this case, the siphoning phenomenon can be effectively generated.

[0010] (3) In the above aspect (1), the elbow joint may have a cleaning port on the side for opening the inside.

[0011] In this case, since the cleaning port is provided on the side surface of the elbow joint, opening and closing the cleaning port and cleaning the inside of the drain pipe are easy.

[0012] (4) In the above aspect (2), a heat insulating layer may be provided on the outer surface of each of the horizontal siphon drain pipe, the elbow joint, the vertical siphon drain pipe, the junction joint, and the storage tank.

[0013] In this case, the insulation performance of the horizontal siphon drain pipe, elbow joint, vertical siphon drain pipe, junction joint, and storage tank can be improved by the insulation layer provided on their outer surfaces, thereby suppressing condensation on each. Furthermore, because the horizontal siphon drain pipe and vertical siphon drain pipe have small flow path inner diameters to generate the siphon phenomenon, the outer diameter can be suppressed even if the insulation layer is thickened. This makes it possible to further improve insulation performance. [Effects of the Invention]

[0014] According to the present invention, the degree of freedom in arranging the air conditioner can be improved, and piping construction becomes easier. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is an overall configuration diagram showing a drain piping structure according to an embodiment of the present invention; [Figure 2] 4 is a perspective view showing a storage tank of the drain piping structure according to the embodiment of the present invention, cut along a vertical plane including a central axis C in FIG. 3. FIG. [Figure 3] FIG. 2 is a plan view showing a storage tank of the drain piping structure according to the embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5]5 is a perspective view of the storage tank of the drain piping structure according to the embodiment of the present invention, cut along a horizontal plane including line VV in FIG. 4. FIG. [Figure 6] FIG. 5 is a cross-sectional view taken along line VV in FIG. 4. [Figure 7] 7 is a cross-sectional view taken along line VII-VII in FIG. 6, illustrating an enlarged view of the vicinity of the end portion of the main flow path on the inlet side. FIG. [Figure 8] 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 6, illustrating an enlarged view of the vicinity of the end portion of the main flow path on the outlet side. FIG. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. [Figure 10] FIG. 2 is a cross-sectional view showing a siphon drain horizontal pipe and a siphon drain vertical pipe of the drain piping structure according to the embodiment of the present invention. [Figure 11] FIG. 2 is an exploded cross-sectional view showing an elbow joint of the drain piping structure according to the embodiment of the present invention. [Figure 12] 1 is a cross-sectional view showing the vicinity of a junction joint of a drain piping structure according to an embodiment of the present invention. [Figure 13] FIG. 10 is a front view showing the vicinity of a junction joint of a modified example of the drain piping structure according to the embodiment of the present invention. [Figure 14] FIG. 10 is a front view showing the vicinity of a junction joint of another modified example of the drain piping structure according to the embodiment of the present invention. [Figure 15] 10A and 10B are two-sided views showing the vicinity of a confluence joint of yet another modified example of the drain piping structure according to the embodiment of the present invention. [Figure 16] 10A and 10B are three-view diagrams illustrating the vicinity of a confluence joint in yet another modified example of the drain piping structure according to the embodiment of the present invention. [Figure 17] 10A and 10B are three-view diagrams illustrating the vicinity of a confluence joint in yet another modified example of the drain piping structure according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A drain piping structure according to an embodiment of the present invention will be described below with reference to the drawings.

[0017] [Drain piping structure] The overall configuration of the drain piping structure according to the embodiment will be described. First, as shown in FIG. 1, a building 200 in which this drain piping structure 1 is used will be described. For example, the building 200 includes a plurality of slabs 201 arranged at intervals in the vertical direction, and exterior and interior walls (not shown). The plurality of slabs 201 are each formed into a plate shape whose thickness direction is along the vertical direction. The exterior and interior walls are each formed into a plate shape whose thickness direction is along the horizontal direction. These slabs 201, exterior and interior walls are formed of reinforced concrete or the like, and constitute the building skeleton of the building 200. For example, building 200 is a multi-story building in which multiple stories (floors) 205 (only one story 205 is shown in FIG. 1) are stacked vertically, each having a pair of slabs 201 spaced apart from one another. Each story 205 is composed of a slab 201 at its upper and lower ends. The following explanation will be given using the first story 205 shown in FIG. 1 as an example. The slab 201 that constitutes the upper end of this first story 205 is referred to as ceiling slab 201(a), and the slab 201 that constitutes the lower end of this first story 205 is referred to as floor slab 201(b). A room R is formed between ceiling slab 201(a) and floor slab 201(b). In addition, when this first layer 205 is an intermediate layer in the vertical direction, the ceiling slab 201(a) of the first layer 205 constitutes the floor slab of the layer (floor) one level above the first layer 205, and the floor slab 201(b) of the first layer 205 constitutes the ceiling slab of the layer (floor) one level below the first layer 205.

[0018] The ceiling slab 201(a) has a slab through-hole 202(a) that passes through it in the vertical direction, and the floor slab 201(b) has a slab through-hole 202(b) that passes through it in the vertical direction.

[0019] Between the ceiling slab 201(a) and the floor slab 201(b), a ceiling material 206 is arranged on the ceiling slab 201(a) side, and a floor material 207 is arranged on the floor slab 201(b) side. The ceiling material 206 and the floor material 207 are each formed in the shape of a plate whose thickness direction runs vertically. The ceiling material 206 and the floor material 207, together with a plate-like wall material 208 whose thickness direction runs horizontally, form a room S0 inside where the residents mainly live. An opening 206a is formed in the ceiling material 206. An attic space S1 is formed between the ceiling material 206 and the ceiling slab 201(a).

[0020] An air conditioner 215, which is an indoor unit of the air conditioning system, is fixed to the ceiling material 206. That is, the air conditioner 215 is placed in room R of the building 200 to condition the air of room S0. The configuration of the air conditioner 215 is not particularly limited. For example, the air conditioner 215 includes a casing 220, a turbofan 225, an indoor heat exchanger 235, a drain pan 240, a drain pump 245, an internal metal drain pipe 250, a check valve 255, and a decorative panel 260. The casing 220 is formed in a box shape with an opening at the bottom. The casing 220 is placed in the attic space S1 and fixed to the periphery of the opening 206a in the ceiling material 206. That is, the air conditioner 215 is installed in the ceiling material 206. The turbofan 225 includes an impeller 226, a fan motor 227, and a bell mouth 228. In the impeller 226, blades 232 are held between a shroud 230 and a hub 231. The center of the hub 231 is fixed to the lower end of the drive shaft of the fan motor 227. The fan motor 227 is fixed to the center of the casing 220.

[0021] The turbofan 225 blows out air radially outward, sucking in air from below as blades 232 rotate with the drive of a fan motor 227. The bellmouth 228 is disposed below the impeller 226 of the turbofan 225. The bellmouth 228 guides the air in the chamber S0 to the impeller 226. The indoor heat exchanger 235 is disposed around the impeller 226 of the turbofan 225. Although not shown, the indoor heat exchanger 235 is connected to an outdoor unit of the air conditioning system via a refrigerant pipe. The indoor heat exchanger 235 functions as an evaporator when the air conditioning system is in cooling operation, and as a condenser when the air conditioning system is in heating operation. The indoor heat exchanger 235 adjusts the temperature and humidity of the air blown out from the turbofan 225.

[0022] The drain pan 240 is disposed below the indoor heat exchanger 235. The drain pan 240 collects drainage generated in the indoor heat exchanger 235 during cooling operation and dehumidifying operation of the air conditioning system. Drain pump 245 is provided inside casing 220 to discharge drainage accumulated in drain pan 240 to the outside of building 200. For example, drain pump 245 is a pressure pump such as a centrifugal pump. For example, drain pump 245 is provided with a drain switch (not shown) that turns on when the water level of drainage water in drain pan 240 reaches a certain level. This drain switch is activated when a predetermined amount of drainage water accumulates in drain pan 240.

[0023] For example, internal metal drain pipe 250 is made of copper, aluminum, or the like. The internal metal drain pipe 250 has an inner diameter of 12.7 mm or less. A first end of internal metal drain pipe 250 is disposed in drain pan 240. Internal metal drain pipe 250 rises almost vertically upward from the first end. Internal metal drain pipe 250 is bent toward the outside of casing 220 near the upper end of casing 220. Check valve 255 is connected to a second end of in-machine metal drain pipe 250. In this specification, "connected" refers not only to a case where the connection is direct without any other member intervening, but also to a case where the connection is indirectly connected via another member intervening. Check valve 255 allows drainage water in internal metal drain pipe 250 to flow toward the outside of casing 220. On the other hand, it restricts drainage water from flowing from the outside of casing 220 into internal metal drain pipe 250. Note that internal metal drain pipe 250 does not necessarily need to be provided with check valve 255.

[0024] The decorative panel 260 is formed in the shape of a rectangular plate in a plan view. In a plan view, an air inlet 261, which is an opening, is formed in the center of the decorative panel 260. A plurality of air outlets 262, which are also openings, are formed in the decorative panel 260. In a plan view, the plurality of air outlets 262 are arranged so as to surround the air inlet 261. The air inlet 261 and the plurality of air outlets 262 are each an opening that penetrates the decorative panel 260 in the up-down direction. The decorative panel 260 is fixed to the periphery of the opening in the casing 220 . An air filter 263 is fixed to the periphery of the air inlet 261 in the decorative panel 260. The air filter 263 removes dust and other particles from the air.

[0025] The drain piping structure 1 discharges drain wastewater generated from an air conditioner 215. The drain piping structure 1 includes an external metal drain pipe 10, a storage tank 310, a horizontal siphon drain pipe 350, an elbow joint 400, a vertical siphon drain pipe 440, a junction joint 11, and vertical resin drain main pipes 80(a), 80(b) that serve as vertical main drain pipes. The junction joint 11 includes a connection portion 20, an expanded diameter portion 45, and a resin insulated joint portion 55. The external metal drain pipe 10 is made of copper, aluminum, or the like. The internal diameter of the external metal drain pipe 10 is 12.7 mm or less. The internal diameter of the external metal drain pipe 10 is preferably 9 mm or more. The length of the external metal drain pipe 10 is preferably 1 m or more and 20 m or less. The external metal drain pipe 10 is preferably provided with a resin foam on its outer surface. A first end of the external metal drain pipe 10 is connected to the check valve 255 of the air conditioner 215. The external metal drain pipe 10 extends so as to be away from the casing 220.

[0026] <Storage Tank 310> The storage tank 310 is connected to the external metal drain pipe 10 and stores drainage water discharged from the drain pan 240 by the drain pump 245. If the drainage water can be allowed to flow naturally from the drain pan 240 to the storage tank 310, the drain pump 245 does not need to be provided on the external metal drain pipe 10. In that case, a thermally insulated pipe can be used instead of the external metal drain pipe 10.

[0027] As shown in Figures 2 and 3, the storage tank 310 has a peripheral wall 310A, which is the main body. The overall shape of the peripheral wall 310A is a rectangular parallelepiped. The peripheral wall 310A is integrally molded from, for example, resin. As shown in Figure 2, the interior of the peripheral wall 310A is divided into a main channel 312, a storage section 314, a partition wall 316 separating the main channel 312 and the storage section 314, and a branch channel 318.

[0028] The main flow path 312 is provided between an inlet 322 connected to the external metal drain pipe 10 shown in Fig. 1 and through which drain wastewater discharged from the drain pan 240 by the drain pump 245 flows in, and an outlet 324 connected to the horizontal siphon drain pipe 350 shown in Fig. 1 and through which the drain wastewater flows out, and extends along the central axis C in Fig. 3. In this embodiment, the inlet 322 and the outlet 324 are each cylindrical in shape and have a circular cross-sectional shape. The central axis C is parallel to the central axes of the cylinders of the inlet 322 and the outlet 324.

[0029] As shown in Fig. 2, the storage section 314 is provided alongside the main flow path 312 on the side of the main flow path 312, and a certain amount of drainage water can be stored in the storage section 314. As shown in Fig. 5, in this embodiment, when the bottom of the main flow path 312 of the storage tank 310 is placed on a horizontal surface and the ceiling of the storage tank 310 is arranged horizontally, the bottom surface of the main flow path 312 is lower than the bottom surface of the storage section 314. In other words, the main flow path 312 is deeper than the storage section 314.

[0030] In this embodiment, a pair of reservoirs 314 are provided on either side of the central axis C of the main flow channel 312, with the main flow channel 312 in between, and each reservoir 314 is in communication with the main flow channel 312. The number of reservoirs is not limited to two, and may be, for example, one, or three or more.

[0031] A pair of partition walls 316 are provided between the main channel 312 and each of the storage sections 314, and extend in the direction of liquid flow in the main channel 312, from top to bottom in FIG. 3. The partition wall 316 separates the main channel 312 from the storage section 314. As shown in FIG. 2, the height of the partition wall 316 is higher than the height of the ceiling portion of the outlet 324. In this embodiment, as shown in FIG. 4, the partition wall 316 is formed by the bottom areas of the peripheral wall 310A located on the left and right of the inlet 322 protruding upward. This allows for a reduction in the amount of resin used as the material for the peripheral wall 310A.

[0032] 5, the partition wall 316 is provided continuously with the inner wall surface of the peripheral wall 310A of the storage tank 310 on the inlet 322 side. In other words, the end of the partition wall 316 on the inlet 322 side is in contact with a portion of the peripheral wall 310A near the inlet 322. Therefore, no gap is formed between the main channel 312 and the storage section 314 at the end of the partition wall 316 on the inlet 322 side.

[0033] In this embodiment, as shown in Fig. 2, a gap is formed between the partition wall 316 and the ceiling portion of the peripheral wall 310A. The gap between the partition wall 316 and the ceiling portion of the peripheral wall 310A may be blocked. The partition wall 316 has an opening 326 formed as a notch in a portion near the outlet 324 (the lower left position in Fig. 2) that connects the main channel 312 side with the storage section 314 side. That is, the opening 326 forms a gap between the outlet 324 and the partition wall 316 in the direction in which the central axis C extends, allowing drainage water to branch off from the main channel 312 and flow.

[0034] In other words, the reservoir 314 is partially connected to the main channel 312 at a position near the outlet 324. The partition wall 316 also guides the flow of drainage water in the main channel 312 to prevent the drainage water from flowing out toward the reservoir 314 until the drainage water reaches the position of the opening 326.

[0035] In this embodiment, the shape of the opening 326 is rectangular, but any other geometric shape such as a polygonal shape or a circular shape may be adopted. In addition, the opening is not limited to a notch and may be, for example, a through-hole formed in the partition wall 316.

[0036] As shown in Fig. 6, branch flow path 318 connects opening 326 and storage section 314. Branch flow path 318 communicates with storage section 314 at a position closer to inlet 322 (upper side in Fig. 6) than opening 326 in Fig. 6.

[0037] 4, main flow path 312 is a region surrounded by recess 313 having an inner surface with a semicircular cross section and a pair of partition walls 316 arranged on both sides of recess 313. Note that, at a position where partition wall 316 is not present due to the formation of opening 326 inside peripheral wall 310A, main flow path 312 is formed only by recess 313.

[0038] In this embodiment, the area of ​​the region formed by an imaginary line connecting the highest points on both sides of the main flow path 312 and the contour of the inner wall surface of the main flow path 312 in a cross section cut by a plane perpendicular to the central axis C of the main flow path 312 is set as the flow path cross-sectional area.

[0039] 7, a dotted pattern is applied to illustrate the flow path cross-sectional area SA of the region formed by an imaginary line 326A connecting the tops of the partition walls 316 on both sides of the main flow path 312 and the outline of the inner wall surface of the main flow path 312 at position PA of the end on the inlet 322 side. Also, in Fig. 8, a dotted pattern is applied to illustrate the flow path cross-sectional area SB of the region formed by an imaginary line 326B connecting the inner surfaces of the bottom portions of the peripheral wall 310A on both sides of the recess 313 and the outline of the inner wall surface of the main flow path 312 at position PB of the end on the outlet 324 side.

[0040] In this embodiment, since no gap is formed between the inlet 322 and the partition wall 316, the highest position on both sides of the recess 313 at position PA of the end of the main channel 312 on the inlet 322 side is the top of the partition wall 316. However, if a gap is formed between the inlet 322 and the partition wall 316, the highest position on both sides of the recess 313 at the end of the main channel 312 on the inlet 322 side may be the inner surface of the bottom portion of the peripheral wall 310A, as in the case of position PB of the end of the main channel 312 on the outlet 324 side in this embodiment.

[0041] 7 and 8, in this embodiment, the flow path cross-sectional area SB at position PB, the end on the outlet 324 side, is smaller than the flow path cross-sectional area SA at position PA, the end on the inlet 322 side. In this embodiment, the flow path cross-sectional area gradually decreases from position PA, the end on the inlet 322 side, to position PB, the end on the outlet 324 side.

[0042] It is not essential that the cross-sectional area of ​​the main channel 312 gradually decreases from the inlet 322 toward the outlet 324. For example, the partition wall may partially bulge outward between the inlet 322 and the outlet 324, thereby partially providing a region having a cross-sectional area larger than the cross-sectional area of ​​the end of the main channel on the inlet 322 side. Alternatively, for example, the outer edge of the main channel may be formed in a stepped or stepped shape in a plan view. The bulge of the partition wall is set within a range that achieves the required liquid flow rate inside the storage tank 310.

[0043] 3, a heat insulating material (heat insulating layer) 330 is wound around the storage tank 310 so as to cover the entire outside thereof. Note that the heat insulating material 330 may be provided in advance so as to cover the entire outside of the storage tank 310, instead of being wound around the storage tank 310.

[0044] 1, the storage tank 310 is installed on the ceiling material 206. Note that a plurality of air conditioners 215 may be connected to one storage tank 310 so that the drainage water from the plurality of air conditioners 215 is stored therein.

[0045] As shown in Figure 9, the storage tank 310 flows the drainage water that flows in from the inlet 322 toward the outlet 324, but when the water level of the drainage water rises inside the storage tank 310, the drainage water flows from the branch flow path 318 into the storage section 314 and is stored inside the storage section 314 (described below).

[0046] <Siphon drain horizontal pipe 350> The horizontal siphon drain pipe 350 shown in Fig. 1 is connected to the outlet 324 of the storage tank 310 shown in Fig. 2. As shown in Fig. 10, the horizontal siphon drain pipe 350 has an inner pipe 351, a heat insulating layer 352 that completely covers the outer surface of the inner pipe 351 on the radial outside, and a coating layer 353 that completely covers the outer surface of the heat insulating layer 352 on the radial outside.

[0047] The inner diameter of the inner pipe 351 through which drainage water flows in the horizontal siphon drain pipe 350 is narrowed to 8 mm or more and 25 mm or less to prevent siphoning. The inner pipe 351 is made of flexible resin such as polybutene or polypropylene, polyvinyl chloride resin, flexible metal such as copper or aluminum, or a multi-layer structure of resin and metal. If the inner pipe 351 is made of flexible resin or flexible metal, fittings are not required when installing it away from other components. Metal pipes such as copper can particularly suppress the generation of slime caused by bacteria. The heat insulating layer 352 is made of a foam material such as cross-linked polyethylene foam. The covering layer 353 covers the outer surface of the heat insulating layer 352 in the radial direction, and is made of, for example, a polyethylene film. The horizontal siphon drain pipe 350 is formed by integrally molding an inner pipe 351, a heat insulating layer 352, and a covering layer 353. As shown in Fig. 1, the horizontal siphon drain pipe 350 is disposed horizontally on the ceiling material 206 along the ceiling material 206. Note that the horizontal here is not limited to a direction perpendicular to the direction of gravity (so-called no gradient), but may also have a gradient that causes drainage to flow downstream (so-called drainage gradient), or a gradient that causes drainage to flow upstream (so-called reverse gradient). By installing the horizontal siphon drain pipe 350 in the ceiling material 206, a drainage gradient, no gradient, or reverse gradient may be randomly generated along the entire length of the horizontal siphon drain pipe 350. In other words, unlike conventional horizontal drain pipes in which the drainage gradient that causes drainage to flow from upstream to downstream is set along the entire length of the horizontal drain pipe, the horizontal siphon drain pipe 350 has no gradient or a reverse gradient along at least a portion between the air conditioner 215 and the elbow joint 400. The siphon drain horizontal pipe 350 may be connected by a joint such as an elbow or socket (not shown). The vertical siphon drain pipe 440 is made of the same material and has the same configuration as the horizontal siphon drain pipe 350 .

[0048] <Elbow fitting 400> One end of elbow joint 400 is connected to the end of horizontal siphon drain pipe 350, which extends laterally from reservoir 310, on the opposite side from reservoir 310. The other end of elbow joint 400 is connected to vertical siphon drain pipe 440 so that it extends vertically downward. As shown in Figure 11, the elbow joint 400 is a joint with a cleaning port. The elbow joint 400 is configured to include a main body 452, a core 454 as a blocking member, and a lid 456. In this embodiment, the main body 452, the core 454, and the lid 456 are formed from synthetic resin. If the horizontal siphon drain pipe 350 is sufficiently flexible and can be used as a vertical siphon drain pipe by bending the horizontal siphon drain pipe 350, the elbow joint 400 may be omitted.

[0049] The main body 452 is made of opaque synthetic resin and includes a cylindrical main body pipe 458. The main body pipe 458 is curved in a substantially L-shape and includes a horizontal portion 458A extending along the axial direction of the horizontal siphon drain pipe 350 and a vertical portion 458B extending from the horizontal portion 458A along the axial direction of the vertical siphon drain pipe 440. The main body pipe 458 also includes a bent portion 458C connecting the downstream end of the horizontal portion 458A to the upstream end of the vertical portion 458B. In other words, the main body pipe 458 forms a cylindrical body curved around the bent portion 458C. The horizontal portion 458A and the vertical portion 458B, located on either side of the bent portion 458C, extend in directions perpendicular to each other. The main body pipe 458 has a constant inner diameter.

[0050] Furthermore, a first connecting portion 460 is integrally formed on the main body pipe portion 458 at the end opposite the bent portion 458C of the horizontal portion 458A, and a second connecting portion 462 is integrally formed on the end opposite the bent portion 458C of the vertical portion 458B.

[0051] The first connecting portion 460 has a larger diameter than the main body pipe portion 458, and the horizontal siphon drain pipe 350 shown in FIG. 1 is inserted and bonded thereto. The second connecting portion 462 has a larger diameter than the main body pipe portion 458, and the upstream end of the vertical siphon drain pipe 440 shown in FIG. 1 is inserted and bonded thereto. In this manner, the elbow fitting 400 connects the horizontal siphon drain pipe 350 and the vertical siphon drain pipe 440, and functions as a bent pipe that drops the piping extending in a substantially horizontal direction (lateral direction) vertically downward. In the elbow fitting 400 of this embodiment, the first connecting portion 460 and the second connecting portion 462 have the same shape, and the inner diameter of the first connecting portion 460 and the inner diameter of the second connecting portion 462 are the same.

[0052] Furthermore, the first connection portion 460 is fixed to the ceiling slab 201(a) shown in Fig. 1 using a fixing means (not shown). As a result, the elbow joint 400 is supported from above by the ceiling slab 201(a).

[0053] A cylindrical side pipe portion 464 is integrally provided with main body pipe portion 458, protruding from main body pipe portion 458 in the opposite direction of first connecting portion 460 in the axial direction of horizontal portion 458A. Specifically, side pipe portion 464 is provided from the side surface of horizontal portion 458A constituting main body pipe portion 458 opposite first connecting portion 460 to the side surface of bent portion 458C opposite first connecting portion 460. The diameter of side pipe portion 464 is formed to be larger than the diameter of main body pipe portion 458.

[0054] A partition wall 466 is provided between the side pipe section 464 and the main body pipe section 458. A cleaning port 468 is formed in the center of the partition wall 466, penetrating the partition wall 466 in the horizontal direction. This allows the interior of the side pipe section 464 and the interior of the main body pipe section 458 to communicate with each other via the cleaning port 468.

[0055] Cleaning port 468 is formed in a long rectangular shape in a side view, and its longitudinal direction coincides with the axial direction of vertical siphon drain pipe 440 shown in FIG. 1. Cleaning port 468 is formed in a position overlapping at least a portion of main body pipe section 458 in a side view, specifically, a portion of horizontal section 458A, bent section 458C, and vertical section 458B. Specifically, cleaning port 468 is formed to be slightly larger than the outer shapes of horizontal section 458A and bent section 458C of main body pipe section 458 in a side view. Therefore, the interiors of horizontal section 458A, bent section 458C, and vertical section 458B can be seen through cleaning port 468 formed in partition wall 466. In addition, at the boundary between the peripheral edge of the cleaning port 468 and the main body pipe section 458, a step section 467 is provided that is formed continuously from the downstream end of the horizontal section 458A of the main body pipe section 458 to the bent section 458C and the upstream end of the vertical section 458B.

[0056] An annular step 470 is formed on the inner peripheral surface of the side tube portion 464, protruding radially inward (toward the center) of the side tube portion 464. Meanwhile, a male thread 472 is formed on the outer peripheral surface of the side tube portion 464 on the side opposite the main body tube portion 458 in the axial direction of the side tube portion 464, and an annular groove 474 is formed on the axial side of the male thread 472 facing the main body tube portion 458. An O-ring 476 is fitted in this annular groove 474.

[0057] A core 454 is inserted into the inside of the side pipe portion 464. The core 454 is made of a transparent synthetic resin. The core 454 has a cylindrical portion 478 that is inserted into the inside of the side pipe portion 464, and a cleaning port closing portion 480 that fits into the cleaning port 468 is formed integrally with the cylindrical portion 478 on the axially opposite side of the cylindrical portion 478.

[0058] An annular groove 482 is formed in the outer peripheral surface of the cylindrical portion 478 on the axial side of the cleaning port closing portion 480, and an O-ring 484 is fitted in this annular groove 482. When the core 454 is inserted inside the side pipe portion 464, the O-ring 484 comes into contact with the inner peripheral surface of the side pipe portion 464, thereby sealing the gap between the core 454 and the side pipe portion 464.

[0059] Cleaning port blocking portion 480 is formed as a plate material curved in an L shape, and is arranged so as to cover cleaning port 468 from the side when core 454 is inserted inside side pipe portion 464. Furthermore, as described above, core 454 is formed from a transparent synthetic resin, and therefore the inside of main body pipe portion 458 can be seen from the outside when core 454 is inserted inside side pipe portion 464. Note that core 454 may also be configured to be formed from a translucent synthetic resin.

[0060] The cleaning port blocking portion 480 has a cross-sectional shape, taken along a direction perpendicular to the direction in which the cleaning port blocking portion 480 extends, that is generally arc-shaped and open toward the main body pipe portion 458. Furthermore, the radius of curvature of the curved surface 486 that forms the inner surface of the cleaning port blocking portion 480 matches the radius of curvature of the inner circumferential surface of the main body pipe portion 458. Therefore, when the cleaning port blocking portion 480 is fitted into the cleaning port 468, the peripheral edge of the cleaning port blocking portion 480 fits into the stepped portion 467, and the curved surface 486 of the cleaning port blocking portion 480 smoothly connects to the inner circumferential surface of the main body pipe portion 458 without any steps. This allows the cleaning port blocking portion 480 of the core 454 to form part of the bent portion 458C. The corner between the inner circumferential surface of the main body pipe portion 458 and the curved surface 486 of the cleaning port blocking portion 480 has a smooth curvature to allow for siphoning.

[0061] The inner periphery of the lid 456 is formed with a female thread 488 that screws onto the male thread 472 of the side tube portion 464, and a contact portion 490 that comes into contact with the O-ring 476 of the side tube portion 464. When the lid 456 is attached to the side tube portion 464, the O-ring 476 of the side tube portion 464 comes into contact with the contact portion 490 of the lid 456, thereby sealing the gap between the side tube portion 464 and the lid 456. The lid 456 is preferably made of a transparent or semi-transparent synthetic resin, similar to the core 454. When the lid 456 is made of a transparent or semi-transparent synthetic resin, the interior of the main body tube portion 458 can be seen through the lid 456 and the core 454 when the lid 456 is attached to the side tube portion 464.

[0062] By removing the lid 456 from the elbow joint 400 and taking out the core 454 from inside the side pipe portion 464, the inside of the siphon drain horizontal pipe 350, the siphon drain vertical pipe 440 and the elbow joint 400 can be cleaned.

[0063] 1, a heat insulating material (heat insulating layer) 430 is wound around the elbow joint 400 so as to cover the entire outside thereof. Note that instead of winding the heat insulating material 430 around the elbow joint 400, the heat insulating material 430 may be provided in advance so as to cover the entire outside of the elbow joint 400.

[0064] <Siphon drain vertical pipe 440> The vertical siphon drain pipe 440 is made of the same material and has the same structure as the horizontal siphon drain pipe 350 described above, and therefore has the same inner pipe 351 , heat insulating layer 352 and covering layer 353 as the horizontal siphon drain pipe 350 . The siphon drain vertical pipe 440 has a straight vertical pipe section 441 extending downward from the elbow joint 400, and a horizontal pipe section 442 extending laterally from the end of the vertical extension section opposite the elbow joint 400. The length of the siphon drain vertical pipe 440 extending downward from the elbow joint 400 or downward below the ceiling material 206 to cause siphoning must be 1.0 m or more, preferably 1.2 m or more, and more preferably 1.5 m. The longer the length, the greater the suction force (negative pressure) of the siphoning phenomenon caused by gravity as the drainage water flows downward, and drainage can be achieved even if the length of the siphon drain horizontal pipe 350 is long and has no slope or a reverse slope. On the other hand, in order to connect to the junction joint 11 located above the floor slab 201(b), it is at least smaller than the height between the underside of the ceiling material 206 and the upper surface of the floor slab 201(b), for example, 4.0 m or less, preferably 3.0 m or less, and more preferably 2.0 m or less.

[0065] <Confluence joint 11> As shown in FIG. 12, the confluence joint 11 has a connection portion 20, an expanded diameter portion 45, and a resin heat insulating joint portion 55. The connecting portion 20 and the expanded diameter portion 45 are each formed in a cylindrical shape. The central axes (axial lines) of the connecting portion 20 and the expanded diameter portion 45 are arranged coaxially with a common axis. Hereinafter, the common axis will be referred to as the axis O1. Because drainage flows in the direction from the connecting portion 20 toward the expanded diameter portion 45, this direction will be referred to as the downstream side. The direction from the expanded diameter portion 45 toward the connecting portion 20 will be referred to as the upstream side. When the connecting portion 20 and the expanded diameter portion 45 are viewed from a direction along the axis O1, the direction perpendicular to the axis O1 will be referred to as the radial direction. The direction going around the axis O1 will be referred to as the circumferential direction. Incidentally, a heat insulating material (heat insulating layer) 90 is wound around the connecting portion 20 and the enlarged diameter portion 45 so as to completely cover the outside of these. Incidentally, instead of winding the heat insulating material 90 afterwards, the heat insulating material 90 may be provided in advance so as to completely cover the outside of the connecting portion 20 and the enlarged diameter portion 45.

[0066] The connection part 20 has a cylindrical receiving port 21 into which the horizontal pipe part 442 of the vertical siphon drain pipe 440 is inserted and adhered. Thus, the connection part 20 is connected to the vertical siphon drain pipe 440. The connection part 20 has a cylindrical thick-walled part 32 downstream of the receiving port 21. The inner diameter of the thick-walled part 32 is smaller than the inner diameter of the receiving port 21. The connecting portion 20 has a cylindrical connecting portion 33 downstream of the thick-walled portion 32. The connecting portion 33 has a tubular piece 38, a tapered piece 39, and a spigot piece 40. The tubular piece 38, the tapered piece 39, and the spigot piece 40 are each formed in a cylindrical shape. The inner diameter of the tubular piece 38, the inner diameter of the tapered piece 39, and the inner diameter of the spigot piece 40 are all equal. These inner diameters are larger than the inner diameter of the thick-walled portion 32. The outer diameter of the cylindrical piece 38 is constant regardless of the position along the axis O1. The outer diameter of the cylindrical piece 38 and the outer diameter of the thick-walled portion 32 are equal to each other. The outer diameter of the tapered piece 39 gradually decreases toward the downstream side. In this example, grooves 39a are formed on the outer peripheral surface of the tapered piece 39 at intervals in the circumferential direction. The outer diameter of spigot piece 40 is constant regardless of the position in the direction of axis O1. The outer diameter of spigot piece 40 is smaller than the outer diameter of tubular piece 38. Spigot piece 40 functions as a spigot. The connection portion 20 is integrally formed from a synthetic resin (resin) such as hard vinyl chloride resin, ABS (acrylonitrile-butadiene-styrene) resin, or polypropylene resin. The enlarged diameter portion 45 and the resin heat insulating joint portion 55 are also made of synthetic resin.

[0067] The configuration of the expanded diameter portion 45 is not particularly limited as long as the inner diameter of the downstream end is larger than the inner diameter of the upstream end. For example, the expanded diameter portion 45 includes a receptacle piece 46 and an expanded diameter piece 47. The receptacle piece 46 and the expanded diameter piece 47 are each formed in a cylindrical shape. The receptacle piece 46 and the expanded diameter piece 47 are arranged coaxially in this order from the downstream side to the upstream side and are configured as an integrated whole. A small diameter portion 46a, whose inner diameter is smaller than the remaining portion, is formed at the downstream end of the inner circumferential surface of the receptacle piece 46. The spigot piece 40 of the connection part 20 is disposed within the receptacle piece 46. The spigot piece 40 is engaged with the small diameter portion 46a of the receptacle piece 46 from the upstream side. The inner diameter of the expansion piece 47 gradually increases toward the downstream side. The outer diameter of the upstream portion of the expansion piece 47 gradually increases toward the downstream side. The outer diameter of the downstream portion of the expansion piece 47 is constant regardless of the position in the direction of the axis O1. The downstream portion of the expansion piece 47 functions as a spigot 47a. The expanded diameter portion 45 is converted so that the inner diameter of the downstream portion of the expanded diameter portion 45 is larger than the inner diameter of the upstream portion of the expanded diameter portion 45.

[0068] The resin insulating joint part 55 is a so-called tee, and is connected to the connection part 20 via the expanded diameter part 45. The resin insulating joint part 55 includes a main body part 56, a first socket 57, a second socket 58, and a third socket 59. The configuration of the main body 56 is not particularly limited as long as it includes an air layer S3, which will be described later. For example, the main body 56 includes an inner cylinder 62 and a lid 63. The inner cylinder 62 includes a cylindrical portion 66 , a first flange 67 , and a second flange 68 . The inner diameter of cylindrical portion 66 is larger than the inner diameter of vertical siphon drain pipe 440. A through-hole 66a is formed in the side surface of cylindrical portion 66. The inner diameter of through-hole 66a is smaller than the outer diameter of spigot 47a of expanded diameter portion 45. Cylindrical portion 66 is disposed so that its axis extends in the vertical direction. The first flange 67 protrudes from the upper end of the cylindrical portion 66 toward the outside in the radial direction of the cylindrical portion 66. The first flange 67 is formed around the entire circumference of the cylindrical portion 66. The second flange 68 protrudes from the lower end of the cylindrical portion 66 toward the outside in the radial direction of the cylindrical portion 66. The second flange 68 is formed around the entire circumference of the cylindrical portion 66 .

[0069] The lid portion 63 is formed into a cylindrical shape as a whole. The outer diameter of the lid portion 63, the outer diameter of the first flange 67, and the outer diameter of the second flange 68 are equal to one another. For example, the lid portion 63 is configured by dividing the lid portion 63 into a first lid piece 71A and a second lid piece (not shown) in the circumferential direction of the lid portion 63. The first lid piece 71A includes a cover 72A, a first leg portion 73A, and a second leg portion 74A. When viewed in the vertical direction, the cover 72A has an arc shape with a central angle of approximately 180°. In other words, the cover 72A is curved so as to be convex toward the radially outward direction of the lid portion 63. The first leg portion 73A protrudes from the upper end of the cover 72A toward the radially inner side of the lid portion 63. The second leg portion 74A protrudes from the lower end of the cover 72A toward the radially inner side of the lid portion 63. The first leg portion 73A and the second leg portion 74A are spaced apart in the vertical direction. The first leg portion 73A and the second leg portion 74A contact the outer peripheral surface of the cylindrical portion 66 from the radially outer side of the cylindrical portion 66. The first leg portion 73A contacts the lower surface of the first flange 67 from below the first flange 67. The second leg portion 74A contacts the upper surface of the second flange 68 from above the second flange 68. The second lid piece is configured similarly to the first lid piece 71A.

[0070] An air layer (heat insulating layer) S3 is formed between the first cover piece 71A and the second cover piece and the cylindrical portion 66. That is, the main body portion 56 has an air layer S3 on the outer surface side. Air is accommodated in the air layer S3. The thermal conductivity of the air layer S3 is lower than that of the main body 56 and the first socket 57 of the resin thermal insulating joint 55. The air layer S3 is formed on the outer peripheral surface of the cylindrical portion 66 over the entire circumference of the cylindrical portion 66.

[0071] The first socket 57 is fixed to the outer peripheral surface of the cylindrical portion 66 so as to surround the through hole 66a. The inner diameter of the first socket 57 is larger than the inner diameter of the through hole 66a and is approximately the same as the outer diameter of the spigot 47a of the expanded diameter portion 45. The peripheral edge of the through hole 66a in the cylindrical portion 66, which protrudes radially inward beyond the first socket 57, constitutes a locking portion 66b. In this manner, the main body 56 connects the first socket 57, the second socket 58, and the third socket 59 to one another. Although the first insulating layer is the air layer S3, the first insulating layer may be a foamed layer such as the foamed resin layer 82(a) of the resin drain vertical main pipe 80(a), which will be described later. The resin insulation joint is preferably made of a transparent material, so that the inside of the resin insulation joint can be seen.

[0072] The spigot 47a of the expanded diameter portion 45 is disposed within the first socket 57. The spigot 47a engages with the locking portion 66b from the radially outer side of the cylindrical portion 66 relative to the locking portion 66b. The first socket 57 is connected to the connecting portion 20 via the expanded diameter portion 45. The spigot piece 40 of the connecting portion 20 is connected to the first socket 57 of the resin insulating joint portion 55 via the expanded diameter portion 45. Second socket 58 and third socket 59 are each formed in a cylindrical shape. Second socket 58 extends upward from the outer peripheral edge of first flange 67. Third socket 59 extends downward from the outer peripheral edge of second flange 68. That is, in resin insulation joint portion 55, the central axes of second socket 58 and third socket 59 and the central axis of first socket 57 are perpendicular to each other. The expanded diameter portion 45 is disposed between the siphon drain vertical pipe 440 and the resin insulated joint portion 55. More specifically, the expanded diameter portion 45 is disposed between the connection portion 20 and the resin insulated joint portion 55.

[0073] Each of the vertical resin drain main pipes 80(a) and 80(b) is disposed to extend in the up-down direction. The vertical resin drain main pipe 80(a) is disposed above the vertical resin drain main pipe 80(b). In this embodiment, the configuration of the vertical resin drain main pipe 80(a) and the configuration of the vertical resin drain main pipe 80(b) are identical to each other. Therefore, the configuration of the vertical resin drain main pipe 80(a) is indicated by adding "(a)" to the number. The configuration of the vertical resin drain main pipe 80(b) corresponding to the vertical resin drain main pipe 80(a) is indicated by the same number as the vertical resin drain main pipe 80(a), or by adding "(b)" to the number and lowercase English letter. This avoids redundant explanation. For example, the inner layer pipe 81(a) of the vertical resin drain main pipe 80(a), which will be described later, and the inner layer pipe 81(b) of the vertical resin drain main pipe 80(b) have the same configuration.

[0074] For example, a resin drain vertical main pipe 80(a) includes an inner layer pipe 81(a), a foamed resin layer 82(a), and a skin layer 83(a). The inner-layer pipe 81(a) is made of a hard vinyl chloride resin and has a circular tubular shape. The foamed resin layer 82(a) is provided on the outer circumferential surface of the inner-layer pipe 81(a). The foamed resin layer 82(a) is formed by foaming a thermoplastic resin composition containing a resin including a vinyl chloride resin and a foaming agent. The skin layer 83(a) is provided on the outer circumferential surface of the foamed resin layer 82(a). In other words, the vertical resin drain main pipe 80(a) has the foamed resin layer 82(a) and is molded integrally with the foamed resin layer 82(a). The inner diameter of the resin drain vertical main pipe 80(a) and the inner diameter of the cylindrical portion 66 of the resin heat insulating joint portion 55 are approximately the same. The resin drain pipe may be constructed by wrapping a foam layer around a resin pipe, etc. In this case, the pipe is made of hard polyvinyl chloride resin, and the foam layer is made of foamed PP (polypropylene) or foamed PE (polyethylene).

[0075] The lower end of the resin drain vertical main pipe 80(a) is disposed within the second receiving port 58 of the resin insulated joint part 55. The lower end of the resin drain vertical main pipe 80(a) is engaged with the first flange 67 of the resin insulated joint part 55 from above the first flange 67. In other words, the second receiving port 58 is connected to the resin drain vertical main pipe 80(a). As shown in FIG. 1, a portion of the longitudinal direction of the resin drain vertical main pipe 80(a) is disposed within the slab penetration hole 202(a) of the ceiling slab 201(a). The resin drain vertical main pipe 80(a) penetrates the ceiling slab 201(a). A filler 211 such as mortar is disposed between the peripheral portion of the slab penetration hole 202(a) in the ceiling slab 201(a) and the resin drain vertical main pipe 80(a). The upper end of the resin drain vertical main pipe 80(a) has a configuration similar to that of the junction joint 11 and is connected to another junction joint (not shown) provided on the layer one level above the first layer 205.

[0076] 12, the upper end of the resin drain vertical main pipe 80(b) is disposed within the third receiving port 59 of the resin insulated joint part 55. The upper end of the resin drain vertical main pipe 80(b) is engaged with the second flange 68 of the resin insulated joint part 55 from below the second flange 68. That is, the third receiving port 59 is connected to the resin drain vertical main pipe 80(b). In this way, the resin drain vertical main pipes 80(a), 80(b) are connected to the resin insulated joint part 55. As shown in FIG. 1, a longitudinal portion of the resin drain vertical main pipe 80(b) is disposed within the slab penetration hole 202(b) of the floor slab 201(b). The resin drain vertical main pipe 80(b) penetrates the floor slab 201(b). A filler 211 is disposed between the peripheral portion of the slab penetration hole 202(b) in the floor slab 201(b) and the resin drain vertical main pipe 80(b). The lower end of the resin drain vertical main pipe 80(b) is connected to another junction joint (not shown) provided on the layer one level below the first layer 205, similar to the junction joint 11. In this way, the siphon drain vertical pipe 440 connects a pair of resin drain vertical main pipes 80(a), 80(b) to each other via a junction joint 11 having a connection portion 20, an expanded diameter portion 45, and a resin insulated joint portion 55. The drain piping structure 1 of this embodiment is connected to one air conditioner 215 in one layer 205.

[0077] Next, the operation of the drain piping structure 1 configured as above will be described. Drain wastewater discharged from the air conditioner 215 installed on the first layer 205 to the drain pan 240 is forcibly discharged into the storage tank 310 via the external metal drain pipe 10 by the drain pump 245 of the drain piping structure 1 installed on the first layer 205, and is stored in the storage tank 310. Wastewater discharged above the first layer 205 flows from the resin drain vertical main pipe 80(a) through the cylindrical portion 66 of the junction joint 11 and down into the resin drain vertical main pipe 80(b). At this time, the drainage water stored in the storage tank 310 is sucked out of the storage tank 310 by the siphon effect, passes through the inner pipe 351 of the siphon drain horizontal pipe 350, the elbow joint 400, the inner pipe 351 of the siphon drain vertical pipe 440, the connection part 20 of the junction joint 11, and the enlarged diameter part 45, and flows into the resin drain vertical main pipe 80(b), and is then discharged outside the building 200.

[0078] 9, drainage water flowing into storage tank 310 from inlet 322 flows toward outlet 324. Inside storage tank 310, part of the drainage water is released to the outside from outlet 324, while the remaining part accumulates near outlet 324, causing the water level near outlet 324 to rise.

[0079] Then, when the drainage water level of the accumulated drainage water exceeds the lower edge of the opening 326 as a result of the continued inflow of drainage water from the inlet 322 into the storage tank 310, some of the accumulated liquid branches off from the main channel 312 and flows into the branch channel 318. Furthermore, when the water level of the drainage water inside the storage tank 310 rises, the drainage water flows from the branch channel 318 into the storage section 314, and a certain amount of drainage water is stored inside the storage tank 310 depending on the volume of the storage section 314 and the inflow rate of the drainage water from the inlet 322. Furthermore, the remaining drainage water from the storage tank 310 other than the stored drainage water flows out from the outlet 324 into the siphon drain horizontal pipe 350.

[0080] In this embodiment, the horizontal siphon drain pipe 350, the elbow joint 400, the vertical siphon drain pipe 440, and the junction joint 11 form a siphon drain channel that generates a suction force due to the siphon force. In the siphon drain channel, the siphon force generated inside can promote the discharge of drain water from the siphon drain pipe.

[0081] In addition, the drain piping structure 1 has the length of the vertical pipe section 441 of the siphon drain vertical pipe 440 set so that the height from the storage tank 310 to the junction joint 11 is 2 m or more, so that drain wastewater can flow smoothly from the storage tank 310 to the junction joint 11 by siphoning due to the difference in water head.

[0082] As described above, according to the drain piping structure 1 of this embodiment, drainage water from the air conditioner 215 can be drawn by the siphon phenomenon through the horizontal siphon drain pipe 350, elbow joint 400, vertical siphon drain pipe 440, and junction joint 11 into the vertical main resin drain pipe 80(b) by negative pressure from the drainage water flowing from the upper floor through the vertical main resin drain pipe 80(a). This eliminates the need for a drainage gradient, which is required when draining water by gravity on the ceiling material 206. Therefore, there is essentially no limit to the distance from the vertical main resin drain pipes 80(a) and 80(b) to the air conditioner 215. Furthermore, because a drainage gradient is not necessarily required, even if the drainage water needs to be installed to avoid obstacles, this minimizes the reduction in flexibility in the placement of the air conditioner 215 and simplifies piping installation. In addition, because the junction joint 11 and the vertical siphon drain pipe 440 are disposed between the ceiling slab 201(a) and floor slab 201(b), which define the room R in which the air conditioner 215 is located, there is no need to penetrate the vertical siphon drain pipe 440 through the slab 201, and there are no restrictions on the construction of the penetration part of the slab 201. This makes construction and installation easier, and it can be installed when renovating a room or a building, or even in a room on the lowest floor.

[0083] Furthermore, according to the drain piping structure 1 of this embodiment, the storage tank 310 is provided between the air conditioner 215 and the horizontal siphon drain pipe 350, which allows the siphon phenomenon to occur effectively. Note that instead of the storage tank 310, a U-trap that causes drainage water to accumulate in the horizontal siphon drain pipe 350 or a reverse slope section may be provided between the air conditioner 215 and the horizontal siphon drain pipe 350. The storage tank 310 may not be provided, and the air conditioner 215 and the horizontal siphon drain pipe 350 may be directly connected.

[0084] Furthermore, according to the drain piping structure 1 of this embodiment, a cleaning port 468 for opening the interior is provided on the side of the elbow fitting 400, so that the siphon drain horizontal pipe 350 and the siphon drain vertical pipe 440 do not get in the way, making it easy to open and close the cleaning port 468 and to clean the interiors of the siphon drain horizontal pipe 350, the elbow fitting 400, and the siphon drain vertical pipe 440.

[0085] Furthermore, according to the drain piping structure 1 of this embodiment, the insulating layer 352 is provided on the outer surface of the horizontal siphon drain pipe 350, the insulating material 430 is provided on the outer surface of the elbow joint 400, the insulating material 352 is provided on the outer surface of the vertical siphon drain pipe 440, the insulating material 90 and the air layer S3 are provided on the outer surface of the junction joint 11, and the insulating material 330 is provided on the outer surface of the storage tank 310. This improves the insulating performance of the horizontal siphon drain pipe 350, the elbow joint 400, the vertical siphon drain pipe 440, the junction joint 11, and the storage tank 310, and suppresses condensation therein. Furthermore, because the horizontal siphon drain pipe 350 and the vertical siphon drain pipe 440 have small flow path inner diameters to generate siphoning, the outer diameters of the horizontal siphon drain pipe 350 and the vertical siphon drain pipe 440 can be prevented from increasing even if the insulating layer 352 is thickened. This further improves the insulating performance.

[0086] Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configurations are not limited to these embodiments, and the present invention also includes modifications, combinations, deletions, etc. of the configurations within the scope of the gist of the present invention. Furthermore, it goes without saying that the configurations shown in each embodiment can be used in appropriate combinations.

[0087] For example, instead of the junction joint 11, a junction joint 11A may be used in which a vertical siphon drain pipe 440A extending downward from an elbow joint 400 is joined at an acute angle to vertical main resin drain pipes 80(a), 80(b) as shown in Fig. 13. In this case as well, a heat insulating layer 90A is provided so as to completely cover the junction joint 11A.

[0088] 14, a junction joint 11B may be used in place of the junction joint 11. The junction joint 11B connects the vertical resin drain main pipes 80(a), 80(b) and extends downward from the elbow joint 400 to join a vertical siphon drain pipe 440B connected vertically to the connection port 21B with the vertical resin drain main pipes 80(a), 80(b). In this case, a heat insulating layer 90B is also provided to completely cover the junction joint 11B.

[0089] 15, instead of the junction joint 11, a junction joint 11C may be used which connects the vertical resin drain main pipes 80(a), 80(b) and has a plurality of connection ports 21C arranged in the circumferential direction to which vertical siphon drain pipes 440C extending downward from elbow joints 400 are vertically connected, and which merges the vertical siphon drain pipes 440C connected to these connection ports 21C with the vertical resin drain main pipes 80(a), 80(b). In this case as well, a heat insulating layer 90C is provided so as to completely cover the junction joint 11C.

[0090] 16, a junction joint 11D may be used that connects the vertical resin drain main pipes 80(a), 80(b) and has a plurality of connection ports 21D arranged horizontally to which vertical siphon drain pipes 440D extending downward from elbow joints 400 are connected at acute angles, and that joins the vertical siphon drain pipes 440D connected to these connection ports 21D with the vertical resin drain main pipes 80(a), 80(b). In this case, too, a heat insulating layer 90D is provided to completely cover the junction joint 11D.

[0091] 17, a junction joint 11E may be used that connects the vertical resin drain main pipes 80(a), 80(b) and has a plurality of connection ports 21E arranged horizontally to which vertical siphon drain pipes 440E extending downward from elbow joints 400 are vertically connected, and that merges the vertical siphon drain pipes 440E connected to these connection ports 21E with the vertical resin drain main pipes 80(a), 80(b). In this case, too, a heat insulating layer 90E is provided to completely cover the junction joint 11E. [Explanation of symbols]

[0092] 1 Drain piping structure 11, 11A~11E Confluence joint 80(a), 80(b) Resin drain vertical main pipe (drain vertical main pipe) 201(a) Ceiling slab 201(b) Floor slab 215 Air conditioner 310 Reservoir 330,430 Heat insulation material (insulation layer) 350 Siphon drain horizontal pipe 352 Insulation Layer 400 elbow fitting 440, 440A~440E Siphon drain vertical pipe 468 Cleaning port Room R

Claims

1. a siphon drain horizontal pipe communicating with the air conditioner; an elbow joint provided on the side of the siphon drain horizontal pipe opposite to the air conditioner; a siphon drain vertical pipe extending downward from the elbow joint; A vertical drain main pipe, a confluence joint that joins the opposite end of the siphon drain vertical pipe from the elbow joint to the vertical drain main pipe; Equipped with The junction joint and the siphon drain vertical pipe are arranged between a ceiling slab and a floor slab that define a room in which the air conditioner is arranged. Drain piping structure.

2. A storage tank is provided between the air conditioner and the siphon drain horizontal pipe. The drain piping structure according to claim 1 .

3. The elbow joint has a cleaning port on the side for opening the inside. The drain piping structure according to claim 1 .

4. a heat insulating layer is provided on the outer surface side of each of the horizontal siphon drain pipe, the elbow joint, the vertical siphon drain pipe, the junction joint, and the storage tank; The drain piping structure according to claim 2 .

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