JPH0674601B2 - Rainwater reservoir - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rainwater storage tank for storing rainwater collected from a roof or the surface of the earth.

Conventional technology Rainwater is collected directly from remote islands far from the main island, in areas where groundwater cannot be used as tap water because it contains salt, or in mountainous remote areas without developing public water supply facilities and in developing countries. And this is used as water for daily life.
For this reason, generally, a water storage facility for storing the collected rainwater is provided.

As a water storage facility of this type, there is a structure made of reinforced concrete, but it is not widely used because it is heavy and requires a professional for construction, and it costs construction cost. In addition, hair cracks frequently occur in the case of incomplete construction, and problems such as deterioration of water quality due to alkali leaching from concrete occur.

Therefore, in developing countries and the like, pottery or a water tank formed by excavating the ground has been used exclusively for storing the collected rainwater.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, these water storage facilities merely store rainwater and are unsanitary.

Therefore, an object of the present invention is to provide a rainwater water storage tank that is lightweight, easily assembled, and inexpensive.

Still another object of the present invention is to provide a rainwater storage tank capable of storing rainwater for a long period of time without deteriorating the water quality of the water stored in the storage tank. The present invention, in order to achieve the above object, a foamed polystyrene resin water storage tank main body having an upper end surface opened, and is fixed to either or both of an inner wall surface and a bottom wall of the water storage tank main body, Reinforcing metal reinforcing wires that are integrated with the water tank body, an inner pipe portion that extends substantially vertically inside the water reservoir body and an outer pipe portion that extends substantially vertically outside the water reservoir body, and the inner pipe portion. A substantially inverted U-shaped siphon composed of a connecting pipe portion arranged to connect the upper end of the outer pipe portion and the upper end of the outer pipe portion and penetrate through the peripheral wall of the water tank body; From the drainage port provided on the inner bottom wall surface of the main body to the outside of the water tank main body, and in the portion extending from the water tank main body to the city, a drain pipe equipped with a drain valve, and from the inside of the water tank main body to the outside of the water tank main body. A water supply pipe having a water supply valve at a portion extending from the water storage tank main body to the outside, a filtering means attached to the water supply pipe, and an opening at an upper end surface of the water storage tank main body can be sealed to provide a water passage function. And an upper lid that prevents sunlight from entering the inside of the water tank body, and the lower end opening of the inner pipe portion of the siphon is located near the bottom wall surface inside the water tank body and functions as an inlet. However, the lower end opening of the outer pipe portion of the siphon is located below the lower end opening of the inner pipe portion, functions as a discharge port, and an intake hole is provided at a predetermined position near the top of the inner pipe portion of the siphon. A water splash formed so as to gradually decrease the inner diameter of the outer pipe portion from above to below in the vicinity of the upper end inside the side pipe portion of the siphon. It is a construction of a rainwater storage tank characterized by.

Operation With the above configuration, when the water level in the water tank body rises and reaches the top of the siphon, the water that has entered the siphon through the inner pipe part from the suction port along with this rises through the connecting pipe part. There is no possibility that the inside of the outer pipe portion of the siphon falls toward the discharge port, the siphon action occurs, the water in the water tank is drained, and the water overflows from the water tank. Further, due to this drainage, when the water level in the water tank body drops to the water level of the intake hole of the siphon, the outside air flows into the siphon from the intake hole, and the siphon action immediately stops. Therefore, wasteful drainage is prevented. In this siphon action, since a water splash is provided inside the outer pipe part of the siphon, the water overflowing from the connecting pipe part to the outer pipe part is generated from below the water splash by the action of this water splash. It becomes small water droplets and falls while filling the inside of the outer tube portion, gradually lowering the air pressure above the siphon. As a result, the siphon action reliably occurs when the water level in the water tank body is slightly lower than the top of the siphon.

Also, since the siphon suction port is located near the inner bottom wall surface of the water tank, the siphon action forces the drainage of water near the water bottom, which tends to become anoxic as a result of the decomposition of debris in the water. Therefore, it is possible to clean the water in the water storage tank.

Since the water tank body is made of styrofoam resin, it is lightweight and easy to assemble, and since it is reinforced by the reinforcing metal streaks, it can sufficiently cope with the water pressure of the stored water.

When the domestic water stored in the water tank is used, the water filtered by the filtering means can be easily taken as necessary by opening the water supply valve of the water supply pipe.

Further, by closing the opening of the upper end surface of the water tank body with the upper lid, it is possible to prevent sunlight from directly entering the water tank, so that the plankton is prevented from being generated in the stored water.

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 and 2, the rainwater storage tank according to the present invention is made of styrofoam resin, and has a cylindrical peripheral wall (2) and a circular bottom wall (3) that closes the lower end opening of the peripheral wall (2). ) Has a water tank body (1). Further, the inner bottom wall surface of the water tank body (1) is formed in a mortar shape that gradually becomes deeper toward the center.

In this case, it is preferable that the water tank body (1) is composed of a plurality of units, and the plurality of units are separately transported to the site and assembled at the site. In this embodiment, , The peripheral wall (2) of the water tank body (1) has three cylindrical peripheral wall units (2a), (2
It is formed by stacking a) and (2a) on top of each other and press-bonding each other with an adhesive or the like. Further, the bottom wall (3) is press-bonded to the lower end opening of the peripheral wall (2), whereby the water tank body (1) is It is configured to be assembled.

Inside each peripheral wall unit (2a), a plurality of ring-shaped reinforcing metal streaks (4) surrounding the peripheral wall are incorporated at predetermined intervals in the vertical direction. In this case, the peripheral wall unit (2a) is, as shown in FIG. 4B, an inner cylinder (5a) made of styrofoam resin having a predetermined diameter and a styrofoam resin fitted to the outer side of the inner cylinder (5a). The outer cylinder (5b) and the outer cylinder (5a) are pressure-bonded to each other while the ring-shaped metal wire is fixed between the outer surface and the inner surface of the outer cylinder (5b).

The configuration of the peripheral wall unit (2a) is not limited to the case of this embodiment. For example, as shown in FIG. 4A,
A peripheral wall unit (2b) may be formed by fixing ring-shaped metal streaks (4) vertically on the outer wall surface of the cylindrical peripheral wall at a predetermined interval, or as shown in FIG. 4D. A laminated body in which a plurality of cylindrical sections are stacked one above the other, and a ring-shaped metal striated wire (4) is formed between the upper end surface of the peripheral wall of the lower section of the adjacent cylindrical section and the lower end surface of the peripheral wall of the upper section. ) May be used as the peripheral wall unit (2d). If it is desired to further increase the strength of the peripheral wall unit, as shown in Fig. 4C, the peripheral wall unit (2c) may be a double-walled ring-shaped metal reinforcing wire incorporated in the peripheral wall. It is also possible to use a grid-like metal streak line instead of the line.

As the reinforcing metal streak wire, it is possible to use a suitable wire such as a stainless wire, a steel wire or a copper wire.

It is also possible to directly transport the granular styrofoam resin raw material to the site, place the metal streak wire in the molding frame in advance, and then expand it at a high temperature to produce the unit. This is particularly effective when implementing the present invention in underdeveloped countries.

On the other hand, inside the bottom wall (3) of the water tank body (1),
As shown in the figure, metal streaks (4) are fixed so as to extend radially from the center of the bottom wall (3) in the horizontal direction. The bottom wall (3) is integrally formed with the styrofoam resin with the metal streak wire (4) incorporated therein, or the bottom wall (3b) is composed of a laminate of two discs. Then, these two discs are formed by pressure bonding with an adhesive in a state in which the metal streaks (4) are sandwiched between the discs.

The shape of the water tank body (1) is not limited to the cylindrical shape as in this embodiment, but may be various shapes depending on the volume of the water tank, the installation location, and the like.

The water tank body (1) includes an inner pipe portion (6a) extending vertically along the inner wall surface of the peripheral wall (2) and an outer pipe portion (6b) extending vertically along the side wall surface of the peripheral wall (2). A connecting pipe part (6) which penetrates the peripheral wall of the water tank body (1) and connects the upper end of the inner pipe part (6a) and the upper end of the outer pipe part (6b).
A substantially inverted U-shaped siphon (6) consisting of c) and is arranged. The lower end opening of the inner pipe portion (6a) is located at a slight distance from the inner bottom wall surface of the water tank body (1),
It functions as a suction port (20), while the lower end opening of the outer pipe portion (6b) is located below the lower end opening of the inner pipe portion (6a) and slightly above the bottom surface of the water tank body (1). Function as a discharge port (21). The top of the siphon (6) is located at an appropriate height such that the siphon action works until the water stored in the water tank body (1) overflows from the upper end of the peripheral wall (2). Further, an intake hole (7) is formed inside the water tank body (1) and on the side surface near the connecting portion between the inner pipe portion (6a) of the siphon (6) and the connecting pipe portion (6c). It Also,
On the upper end of the inner wall surface of the outer pipe portion (6b), a water splash (8) having a slope that gradually narrows the inner diameter of the outer pipe portion (6b) from the upper side to the lower side is provided.

Further, inside the water tank body (1), a water tank body connected to a vertical pipe portion (9a) extending along the central axis of the water tank body (1) and a lower end of the vertical pipe portion (9a). An L-shaped water supply pipe (9) including a horizontal pipe portion (9b) extending through the peripheral wall (2) in the radial direction of (1) is arranged. The upper end of the vertical pipe portion (9a) of the water supply pipe (9) is located at substantially the same height as the intake hole (7) of the siphon (6), and its opening is sealed, and a large number of water passages are provided on its side surface. A hole (10) is formed, on the other hand, the tip of the horizontal pipe portion (9b) projects from the peripheral wall (2) of the water tank body (1) to the outside of the body (1), and the water supply valve ( 12) is installed. Further, the vertical pipe portion (9a) of the water supply pipe (9) is fitted to the outer periphery thereof and extends substantially over the length of the vertical pipe portion (9a), and all the water passage holes of the water supply pipe (9). A filter (11) having a cylindrical shape for covering (10) and containing charcoal grains or the like is mounted inside.

A drainage port (13) is formed near the center of the inner bottom wall surface of the water tank body (1), and extends from the drainage port (13) through the inside of the bottom wall (3) with a slight inclination. A drainage pipe (14) protruding outward from the side portion of the bottom wall (3) is provided, and a drainage valve (15) is attached to the portion of the drainage pipe (14) protruding outward from the bottom wall side portion.

The upper end surface opening of the water tank body (1) can be closed by an upper lid (16). The upper lid (16) has the same structure as the peripheral wall unit (2a) except that the height is slightly lower, and a wire mesh (17) is attached to the lower end face opening of a cylinder, and the upper end face opening is made of a styrene foam circle. It consists of a plate (18) sealed. Further, a water pipe (19) having one end connected to a gutter (not shown) is located at a part of the disc (18) that closes the upper end opening, and the other end is located above the wire net (17) in the upper lid. It is installed as if it were done.

In the above configuration, when there is rainfall, rainwater introduced from the roof flows into the water tank body (1) through the wire net (17) of the upper lid (16). In this case, coarse gravel or coarse dust is removed by being caught by the wire net (17) of the upper lid (16). Also, by using the upper lid (16),
The sunlight is not radiated into the water tank, phytoplankton is prevented from being generated in the storage water, and harmful insects are also prevented from being mixed into the storage water.

Now, assuming that the roof area of one family is RA, the number of families is N, the runoff rate is C, and the duration of rainfall is T, the amount of water that can be stored with the rainfall amount of R is V = C × N × RA × R (1) and the flow rate Q at this time is Q = V / (DT) (2)

In this way, the maximum rainfall in the past is examined and the size of the water conduit (19) with sufficient water flow capacity is determined. The water conduit (19) is composed of, for example, an Eslon pipe or the like.

The capacity of the water tank main body (1), that is, its inner diameter and height, is set so that the amount of water stored in the water tank does not become zero over the course of a year, and is simulated for over 10 years using the above equation (2). The result is determined.

The water depth of the water tank body (1) gradually rises every time there is rainfall, from the state where the stored water amount is zero. Naturally, the rise of the water level exerts a load on the polystyrene foam resin, and the size thereof gradually increases. As the Styrofoam resin forming the water tank body (1),
Use a density of around 01 to 0.02. In this case, the commercial product has a tensile strength of about 2 kg / cm ² .
However, since the water pressure exerted on the water tank body (1) continuously operates for a long period of time, the styrofoam resin may be plastically deformed and the water tank body (1) may be destroyed. For this purpose, the styrofoam resin is reinforced with metal streaks. It is also necessary to take into consideration the possibility that an earthquake will exert an instantaneous and extremely large load on the water tank.

Where: w = water density, Z = water depth, D = diameter of water tank body, b = peripheral wall thickness of water tank body, P ₀ = safety tension of styrofoam resin only, P _a = styrofoam reinforced with metal wire If the safety stress of the resin, P ₃ = allowable stress of the metal wire, and P = total tension acting on the peripheral wall of the water tank body, the following formula is established.

P = w × Z × D (3) P = P _a × 2 × b (4) Therefore, To get Next, if the maximum water depth is H and w = 1 ton / m ³ , H = 3 m, D = 2 m, P ₀ = 2 kg / cm ² , and b = 0.10 m, then P _a = 3 kg / cm ² is obtained. This value is P ₀ = 2kg / c
It is larger than m ² , indicating that it cannot be safely supported only by Styrofoam resin.

For this reason, it is necessary to reinforce the metal wire. In the peripheral wall unit of FIG. 4B, in the case of stainless steel metal reinforcing wires, the arrangement density of the metal reinforcing wires is 0.
If the tensile strength of the metal wire is P _s = 5000 kg / cm ² and the allowable strength load of the metal wire is 0.0005 × 5000 = 2.5 kg / cm ² , the total strength of the polystyrene foam and metal wire is As
2.0 + 2.5 = 4.5kg / cm ² effect will be generated, P
Sufficient tension is generated for _a = 3 kg / cm ² .

The water level in the water tank body (1) rises, and the siphon (6)
When the water reaches the top of the siphon (6) from the suction port (20) through the inner pipe portion (6a), water that has entered the siphon (6) passes through the connecting pipe portion (6c) and the siphon (6). The inside of the outer pipe part (6b) is dropped toward the discharge port (21). This water falls into small water droplets while filling the inside of the outer pipe portion (6b) by the action of the water splash (8) projecting inside the outer pipe portion (6b), and the air pressure above the siphon is reduced. Gradually lower. Therefore, when the water level in the water tank body (1) is slightly lower than the top of the siphon (6), the siphon action surely occurs, the water in the water tank body (1) is drained, and the water is discharged from the water tank. It does not overflow. When this drainage lowers the water level in the water tank body (1) to the water level in the intake hole (7) of the siphon (6), outside air flows into the siphon (6) from the intake hole (7), and the siphon action is Stop immediately. Therefore, wasteful drainage is prevented.

In this embodiment, a water splash (8) is provided on the outer pipe portion (6b) of the siphon (6), but the siphon action is produced without the water splash (8). It is possible. However, in this case, the certainty of the siphon action is somewhat less than that in the case where the water splash (8) is provided.

Since the water surface in the water tank is in contact with the outside air, oxygen dissolves into the water, so the water near the water surface is relatively clean, but the water near the water bottom decomposes as a result of the debris in the water. Tends to be anoxic. However, since the suction port (20) of the siphon (6) is arranged in the vicinity of the inner bottom wall surface of the water tank body (1), such a wastewater is forcibly discharged to the outside by the siphon action. It is possible to purify the water quality in the water tank.

When using the domestic water stored in the water tank body (1), the water supply valve (12) of the water supply pipe (9) is opened. At this time, the water in the water tank body (1) is filtered by the filter (11) and then discharged from the water supply port (9c) of the water supply pipe (9). Then, after collecting the required amount of water, the water supply valve (12) is closed.

Since the water tank body (1) is made of styrofoam resin, it is lightweight and easy to assemble, and since it is reinforced by the metal streaks, it can sufficiently cope with the water pressure of the stored water.

Despite the wire mesh (17) attached to the top lid (16)
As for the dust that settles in the water tank body (1), the inner bottom wall surface of the water tank body (1) has a mortar shape that gradually becomes deeper toward the center, so it is relatively easy to get near the drainage port (13). get together. Therefore, by appropriately opening the drain valve (15), the water can be discharged to the outside of the water tank body (1).

The size of the rainwater storage tank in this example is as follows.

Height 3m, inner diameter 2m, water tank wall thickness 0.1m, inner diameter of siphon pipe
0.1m, intake filter diameter 20cm, total rainfall 120mm, maximum hourly rainfall R = 50mm / hour, rainfall duration T = 3600 seconds, roof area RA = 200m ² , outflow rate C = 100%, maximum discharge Q = 0.0028m ³
/ Sec, planned rainwater storage tank volume V _p = 9.42 m ³ , total rainwater volume V
= 24 m ³ , spill discharge volume V-V _p = 14.58 m ³ .

Further, the peripheral wall unit was a cylindrical shape having an inner diameter of 2 m, a thickness of 0.1 m, and a height of 1 m, and the metal wire occupies an area corresponding to 0.05% of the vertical cross section of the cylinder.

EFFECTS OF THE INVENTION As described above, according to the present invention, the water storage tank main body is made of styrofoam resin and is reinforced by the reinforcing metal streaks, so that it is lightweight and easy to assemble. Therefore, if the water tank body is composed of an assembly of a plurality of units and the units are separately transported, they can be easily transported to a remote place and can be easily assembled locally by an amateur. be able to. Further, it is possible to provide an economical rainwater storage tank that does not require much manufacturing cost.

Further, by causing or stopping the siphon action according to the fluctuation of the water level in the water storage tank, it is possible to prevent the water from overflowing from the water storage tank and automatically store and drain the water. Regarding this siphon action, according to the present invention, since the water splash is provided inside the siphon, the siphon action reliably occurs when the water level in the water storage tank reaches the predetermined water level. Also, due to the action of the siphon, the water near the water bottom, which tends to become anoxic as a result of the decomposition of dust in the water, is forcibly drained, and the upper end opening of the water tank body is closed by the upper lid, Since sunlight is prevented from directly entering the inside of the water tank, plankton is prevented from being generated in the stored water, so that the water quality in the water tank can be purified, which is extremely desirable from the viewpoint of hygiene. .

In view of the above points, the present invention is particularly applicable to remote islands far from the main island, regions with little public water supply facilities, low-developed countries or remote areas where water for daily use must be obtained by collecting rainwater. , Considered to make a significant social contribution.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing one embodiment of a rainwater storage tank according to the present invention, FIG. 2 is a longitudinal sectional view of the rainwater storage tank shown in FIG. 1, and FIG. The cross-sectional view showing the reinforcing structure of the bottom wall of the rainwater storage tank shown in the figure by the metal streak, FIGS. 4A to 4D are the structures of the peripheral wall unit forming the peripheral wall of the rainwater storage tank shown in FIG. FIG. (1) …… Water tank body (2) …… Peripheral wall (3) …… Bottom wall (4) …… Metallic wire (6) …… Siphon (7) …… Intake hole (8) …… Water splash (9) …… Water supply pipe (11) …… Filter (12) …… Water supply valve (13) …… Drain port (14) …… Drain pipe (15) …… Drain valve (16) …… Top lid (20 ) …… Suction port (21) …… Discharge port

Claims (1)

[Claims] 1. A water storage tank body made of styrofoam resin having an open upper end surface, and a structure integrated with the water storage tank body, which is fixed to one or both of the inside and the wall of the peripheral wall and the bottom wall of the water storage tank body. A reinforcing metal streak forming an inner pipe portion that extends substantially vertically inside the water tank body and an outer pipe portion that extends substantially vertically outside the water tank body, and the upper and outer pipe portions of the inner pipe portion. A substantially inverted U-shaped siphon consisting of a connecting pipe portion that is connected to the upper end and penetrates the peripheral wall of the water tank body, and a drainage port provided on the inner bottom wall surface of the water tank body A drain pipe extending outside the main body and having a drain valve in a portion extending from the water tank main body to the outside, and extending from the inside of the water tank main body to the outside of the water tank main body, and the water tank main body. A water supply pipe provided with a water supply valve in a portion extending from the body to the outside, a filtering means attached to the water supply pipe, a top end surface opening of the water storage tank main body can be sealed, and a water passage function is provided, and a sunbeam A top lid that prevents the water from entering the inside of the water tank body, the lower end opening of the inner tube portion of the siphon is located near the bottom wall surface inside the water tank body, and functions as a suction port. The lower end opening of the outer pipe portion is located below the lower end opening of the inner pipe portion, functions as a discharge port, and an intake hole is formed at a predetermined position near the top of the inner pipe portion of the siphon. Near the upper end of the inside of the outer pipe portion of the siphon, a water splash formed so as to gradually decrease the inner diameter of the outer pipe portion from above to below is provided. Use the water storage tank.