JP6190992B1 - Rainwater storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rainwater storage system suitable for effectively using stored water as "clean water". SOLUTION: A rainwater storage system 1 for storing inflowing rainwater, comprising a water storage tank 3 for storing rainwater and a water intake portion 7 for taking in water stored in the water storage tank 3, wherein the water storage tank 3 is made of crushed stone. The filled crushed stone layer 27 exists, and the water intake section 7 draws rainwater flowing into the water storage tank 3 through the crushed stone layer 27, thereby generating a flow of water in the crushed stone layer 27. The microorganisms are allowed to survive on the surface of the crushed stone by the flow of water generated at the same time, and the water purified by the microorganisms is taken in the crushed stone layer 27. [Selection] Figure 1

Description

  The present invention relates to a rainwater storage system, and more particularly to a rainwater storage system that stores inflowing rainwater.

  The applicant has developed and sold an embedded rainwater storage system (see Patent Document 1). FIG. 7 is a diagram showing an outline of an embedded rainwater storage system proposed by the applicant. The rainwater storage system 101 excavates the ground surface, installs a sheet 103 (protective sheet and water shielding sheet), and installs a water intake sheath 105. Then, the crushed stone layer 107 filled with the crushed stone and the backfilling soil 109 are formed by rolling the backfilling soil thereon. The thickness of the backfill soil layer 109 is, for example, 80 cm. Rainwater is stored in the gap between stones in the crushed stone layer 107. Then, water is taken in by the pump 111 using the water intake sheath 105. This is an economically excellent rainwater storage system, and the applicant has made various contributions not only domestically but also internationally.

JP2013-137187A

  In the rainwater storage system described in Patent Document 1, the crushed stone layer is exclusively provided to utilize the top of the water storage tank. If the rainwater storage system is regarded as merely for storing water, a hollow tank, for example, has a large amount of stored water. Therefore, since the rainwater storage system described in Patent Document 1 is filled with crushed stone, the amount of stored water is small and the evaluation tends to be low.

  The applicant considers that it is important that the rainwater storage system not only stores water but also effectively uses water, that is, the stored water. Then, in the rainwater storage system, in addition to being able to store water, how to store water is also important. That is, in the rainwater storage system, not only the water is stored but also the quality of the stored water is important. However, the quality of the stored water has not been noticed by researchers and traders, and has not been measured with what has been installed so far.

  Therefore, an object of the present invention is to provide a rainwater storage system suitable for effectively using stored water as “clean water”.

  A first aspect of the present invention is a rainwater storage system for storing inflowing rainwater, comprising a water storage tank for storing the rainwater, and a water intake section for taking in water stored in the water storage tank, , There is a crushed stone layer filled with crushed stone, and the water intake section draws the rainwater flowing into the water storage tank through the crushed stone layer, thereby generating a flow of water in the crushed stone layer, Microorganisms are allowed to survive on the surface of the crushed stone by the flow of water generated in the crushed stone layer, and water purified by the microorganisms is taken in the crushed stone layer.

  A second aspect of the present invention is the rainwater storage system according to the first aspect, wherein the crushed stone filled in the crushed stone layer is a single-grain crushed stone and has a higher degree than when the particle size is smaller and larger. It is something to purify.

  A third aspect of the present invention is the rainwater storage system according to the first or second aspect, wherein a part or all of the crushed stone filled in the crushed stone layer is filled in the crushed stone layer, The microorganisms on the surface of the crushed stone are cured.

  A fourth aspect of the present invention is the rainwater storage system according to any one of the first to third aspects, wherein the crushed stone layer is added with an attachment that activates purification by the microorganisms.

  According to a fifth aspect of the present invention, there is provided a rainwater storage system according to any one of the first to fourth aspects, comprising a water flow control means for generating a flow of water in the crushed stone layer separately from the water intake section. It is.

  A sixth aspect of the present invention is the water storage system according to the fifth aspect, wherein the water flow control means allows a gas and / or liquid different from the rainwater to flow into the crushed stone layer.

  A seventh aspect of the present invention is the water storage system according to the fifth or sixth aspect, wherein the flowing water control means generates a temperature difference in the water inside the crushed stone layer by heat exchange with a building.

  An eighth aspect of the present invention is the water storage system according to any one of the first to seventh aspects, wherein there are a plurality of the water intakes, and each of the water intakes depends on the quality of the water taken in the water intakes. By changing the water intake amount of the section, the flow of water in the crushed stone layer is changed to change the water quality of the water taken by each water intake section.

  In the rainwater storage system according to each aspect of the present invention, the present invention may be regarded as rainwater flowing into the upper portion of the water storage tank and the water intake portion taking water in the lower portion of the crushed stone layer.

  Here, changing the flow of water in the crushed stone layer means changing the direction and / or amount of water moving in the crushed stone layer. In addition, changes in water quality include, for example, the number of general bacteria, pH value, nitrate nitrogen, nitrite nitrogen, iron (its compound), hydrochloride ion, hardness (calcium / magnesium, etc.), organic matter (TOC), taste , Odor, chromaticity, turbidity, etc. are partly or entirely changed.

  According to each aspect of the present invention, “clean water” can be stored in a water storage tank by purification with microorganisms present on the surface of crushed stone. In general, water quality has been considered to deteriorate when storing water. Therefore, it has not been expected to store “clean water” in the water storage system.

  In each aspect of the present invention, the settling distance from the inflow of rainwater to the crushed stone layer is short. In the crushed stone layer, the surface area is increased because the crushed stone is filled. Therefore, it exists in the environment where purification | cleaning by the microorganisms which exist on the surface of a crushed stone functions effectively.

  The applicant has made it clear for the first time through experiments that “clean water” can be stored in cooperation with Kyushu University. And by this patent application, the applicant can continuously maintain the water purification environment by using the flow of water in the crushed stone layer generated by water intake, and can continue purification by microorganisms present on the surface of the crushed stone. It was made clear that it was possible.

  To store such “clean water” cannot be derived from the common sense that water quality deteriorates due to stored water. The fact that the applicant has developed it independently and continued to install it has been clarified through headings and experiments. In particular, the distance between the inflow portion and the intake portion of the rainwater is more than half of the maximum width of the water storage tank, so that the water storage tank is divided in half, and the inflow portion of rainwater exists on one side and the intake portion exists on the other side. It is possible to make a flow of water as a whole, not a part of the crushed stone layer.

  In addition, for purifying water, it is known to fill a granular material and function as a filter for filtration. However, this is not for water storage.

  Furthermore, as it exists in the 5th-7th viewpoint of this invention, you may make it change the flow of the water by water intake with another element, or may change with water quality.

  According to the 5th viewpoint of this invention, you may make it produce the flow of water by a flowing water means in a crushed stone layer.

  In particular, according to the 6th viewpoint, a flowing water means can flow in gas and a liquid, and can control the flow of the water in a crushed stone layer. If attention is paid only to the purpose of storing water as in the prior art, such inflow is unnecessary. According to the present invention, the flow of water can be controlled by providing such an additional configuration while paying attention to the flow of water for water purification.

  Moreover, according to the 7th viewpoint, the flow of water can be changed using the heat | fever by heat exchange. Conventionally, heat exchange has been focused on heat storage. Therefore, we have focused on how much heat can be stored in the entire water tank. According to the present invention, it is possible to control the flow of water by focusing on the flow of water for water purification and generating a temperature difference in the water inside the crushed stone layer.

  According to the eighth aspect of the present invention, by adjusting the amount of water intake at each point using a plurality of water intakes, not only the linear flow of water between the inflow part and the water intake part but also the inflow part. And planar water flow control with a plurality of water intake units. Thereby, the purified water using the whole crushed stone layer can be utilized effectively.

It is a block diagram which shows an example of a structure of the rainwater water storage system which concerns on embodiment of this invention. It is a figure which shows an example of the positional relationship of the water intake position and inflow position of the water storage tank 3 of FIG. It is a figure explaining the test water storage container for the experiment of the water quality purification performance by the rainwater storage system of this invention. It is a 1st figure which shows the experimental result by the test water storage container of FIG. It is a 2nd figure which shows the experimental result by the test water storage container of FIG. FIG. 4 is a third view showing an experimental result using the test water storage container of FIG. 3. It is a figure which shows an example of a structure of the conventional rainwater storage system.

  Embodiments of the present invention will be described below with reference to the drawings. The embodiment of the present invention is not limited to the following examples.

  FIG. 1 is a block diagram showing an example of the configuration of a rainwater storage system according to an embodiment of the present invention. The rainwater storage system 1 includes a water storage tank 3 (an example of a “water storage tank” in the claims of the present application), a water intake sheath 5, a pump 7 (an example of the “water intake part” of the present application claims), a delivery unit 9, The delivery pipe 11 (a combination of the delivery unit 9 and the delivery pipe 11 is an example of “flowing means” in the claims of the present application). The pump 7 includes a water intake amount adjustment unit 15.

  One end of the conduit 17 is the gutter 21 of the building 19 (an example of the “building” in the claims of the present application), and the other end is on or inside the backfill soil layer 29 of the water tank 3 (other than the conduit 17). The end is an example of an “inflow portion” in the claims of the present application), and guides rainwater falling on the building 19 to the water storage tank 3. The building 19 includes a heat exchanging unit 23 (another example of the “flowing means” in the claims).

  The water tank 3 is created by excavating the ground surface. That is, the ground surface is excavated, the sheet 25 (protective sheet and water shielding sheet) is installed, and the water intake sheath and the pipe 5 are installed. Then, a crushed stone layer 27 (an example of a “crushed stone layer” in the claims of the present application) filled with crushed stone and a backfill soil 29 are formed by rolling the backfill soil thereon. The thickness of the backfill layer 29 is, for example, 80 cm. Therefore, the settling distance from the inflow of rainwater to the crushed stone layer is short. Rainwater is stored in the gap between stones in the crushed stone layer 27.

  The water intake sheath 5 has a lower end in the crushed stone layer 27 and an upper end on the backfill layer 25. The pump 7 is provided in the upper part of the water intake sheath 5 and takes in the water stored in the crushed stone layer 27 using the fact that the lower end of the water intake sheath 5 is in the crushed stone layer 27. The intake amount adjusting unit 15 is for adjusting the intake amount.

  Rainwater that falls on the building 19 is collected in the rain gutter 21 and flows into the water tank 3 through the conduit 17. This is stored in the space between the stones of the crushed stone layer 27 via the backfill soil layer 29. The pump 7 takes in water stored in the crushed stone layer 27. Water can be caused to move in the crushed stone layer 27 of the water storage tank 3 by water intake by the pump 7.

  In the crushed stone layer 27, since the crushed stone is filled, the surface area is increased. Microorganisms are alive on the surface of the crushed stone of the crushed stone layer 27. Therefore, it exists in the environment where purification | cleaning by the microorganisms which exist on the surface of a crushed stone functions effectively. Here, the purification of water means that the water quality is changed and becomes equal to or higher than a reference value. Changes in water quality include, for example, the number of general bacteria, pH value, nitrate nitrogen, nitrite nitrogen, iron (compound), hydrochloride ion, hardness (calcium / magnesium, etc.), organic matter (TOC), taste, odor It is to change part or all of chromaticity, turbidity, etc. Water can be purified by microorganisms that live on the surface of the crushed stone. Then, it is possible to continuously maintain the water purification environment using the flow of water in the crushed stone layer generated by water intake, and to continue purification by microorganisms present on the surface of the crushed stone.

  An example of the movement of the water stored in the crushed stone layer 27 will be described with reference to FIG. For simplicity, it is assumed that the water tank 3 is circular.

With reference to FIG. 2A, a Δ mark is a water intake position 33 by the pump 7. A cross indicates a rainwater inflow position 35 through the conduit 17. The distance D between the water intake position 33 and the inflow position 35 is at least half the width W of the water intake tank 3. Thus, with reference to a certain center line L ₁ (for example, a line passing through the center of the water storage tank 3 and perpendicular to the line segment connecting the water intake position 33 and the inflow position 35), the water intake position 33 is on one side and the water intake position 33 is on the other side. The inflow position 35 can be set, and the water storage tank 3 can move water widely rather than locally.

  In the case where there is one intake position 33, water moves from the inflow position 35 toward the intake position 33 as shown in FIG.

  On the other hand, a plurality of water intake positions 33 may be provided as shown in FIGS. For simplicity, a water intake position 37 is provided in addition to the same water intake position 33 as that shown in FIGS. As shown in FIG. 2C, when water is taken from only the water intake position 33, the movement of water is the same as in FIG. As shown in FIG. 2D, when water is taken from only the water intake position 37, a new water movement occurs. As shown in FIG. 2 (e), when water is taken from both, new water movement can be caused. In this way, by taking water from a plurality of water intake positions, it is possible to cause water to move in a complicated manner over a wider range.

  Therefore, by making the distance between the water intake position and the inflow position more than half of the width of the water storage tank 3, water movement occurs in a wide range, and furthermore, a plurality of water intake positions makes it wider and more complicated. The water can be moved to the crushed stone layer 27, and the water purification of the crushed stone layer 27 can function more effectively.

  The water intake amount adjustment unit 15 may adjust the water intake amount according to the quality of the water taken. For example, when polluted, reduce the amount of water intake to increase the time for microorganisms to function, or if the degree of purification differs at multiple water intake locations, increase the amount of water taken at a clean water intake location to remove dirty water intake. You may make it reduce the amount of water intake of a position.

  The delivery pipe 11 has a lower end on the crushed stone layer 27 and an upper end on the backfill soil layer 29. In the portion of the delivery pipe 11 in the crushed stone layer 27, for example, a plurality of holes are provided. The sending section 9 is provided on the top of the sending pipe 11. Using the fact that the lower end of the delivery pipe 11 is in the crushed stone layer 27, the sending unit 9 sends a gas or liquid different from rainwater to the crushed stone layer 27. For example, air is sent out or purified water is sent out. Thereby, the movement of water can be produced in the crushed stone layer 27.

  The heat exchange unit 23 exchanges heat between the building 19 and the water tank 3. Here, the heat exchanging unit 23 causes the movement of water by providing a temperature difference in the crushed stone layer 27. In the conventional heat exchange, in order to store heat, attention has been paid only to the amount of heat stored in the entire water storage tank 3. The present invention focuses on the temperature difference in the crushed stone layer 27 in order to focus on the vector quantity of water movement.

  Then, the experiment conducted in order to confirm the water quality purification performance by the rainwater storage system of this invention is demonstrated. This is an experimental study of whether or not there is a difference in the water quality change process of rainwater by changing the filling in the rainwater storage tank. The experiment was started on January 7, 2016, and water was collected four times on the first day, the 21st day, the 42nd day, and the 63rd day. In this experiment, it was very interesting that the water quality varies greatly depending on the packing.

  FIG. 3 is a diagram for explaining a test water storage container for an experiment on water purification performance by the rainwater storage system of the present invention. The test water storage container 51 is a container container of about 54 × 40 × 34 cm. Wash containers with tap water and dry.

The crushed stone 55 is the following six types. Cracked stone (particle size 20cm), crusher run, fine gravel (particle size 2 to 4.75mm), coarse sand (particle size 0.85 to 2mm), cracked stone (particle size 10cm), single grain crushed stone 4 (particle size about 20mm) . In addition, the crushed stone uses what was adjusted with the same stone material. Check the porosity of the crushed stone used. For comparison, a two-stage upper and lower stage made of a mesh such as plastic and a rainwater-only one are also prepared. In addition, for walnut stone (particle size: 10 cm) and single- grain crushed stone No. 4, those with additives added to activate microorganisms are also prepared.

  Rainwater should be taken in and out from the same location. In FIG. 3, it picks out from one corner | angular 53, and it extract | collects from the position of 5 cm from the bottom face with the valve | bulb 59 installed diagonally. The pipe 57 is a drainage PVC pipe (inner diameter: 16 mm).

  After rinsing lightly with rainwater using a water storage container containing crushed stone, the rainwater is full and pre-cured for 2-3 weeks.

  Each reservoir that has created rainwater is filled with water, and water quality data is collected at regular intervals and used as analysis data. In addition, rainwater is analyzed before use. Water quality analysis items are drinking well inspection items, that is, water quality analysis items are water temperature, general bacteria, Escherichia coli, nitrate nitrogen and nitrite nitrogen, iron and its compounds, chloride ions, calcium and magnesium, etc. (hardness) , Organic matter (TOC), pH value, taste, odor, chromaticity, and turbidity. The analysis method shall be the analysis method defined by the tap water quality standard.

  4-6 is a figure which shows the experimental result by the test water storage container of FIG.

FIG. 4 shows only the rainwater and the mesh two-stage inspection results for comparison. FIG. 5 shows the test results of cracked stone (particle size 20 cm), crusher run, fine gravel (particle size 2 to 4.75 mm), and coarse sand (particle size 0.85 to 2 mm). FIG. 6 compares the case where the additive is not added with the case where the additive is added with respect to the cracked stone (particle size: 10 cm) and the single- grain crushed stone No. 4. Each water quality analysis item is shown in the “Item” column. Water quality standards for each water quality analysis item are shown in the column “Tap water quality” in FIG.

  The raw water is rainwater, and compared to tap water quality standards, general bacteria and pH do not meet the tap water quality standards.

  For general bacteria, the value was as high as 18,000 individuals / ml at the start of the experiment, but after 3 weeks it was significantly reduced to about 1,000 individuals / ml for “rainwater only” and “two-stage mesh”. Even when the mesh is introduced, nothing is almost the same as in the case of “rainwater only”, and it can be seen that it does not contribute to the reduction of general bacteria.

  On the other hand, other fillings are greatly reduced to 100 individuals / ml. In particular, single-grain crushed stone continues to decrease until after 6 or 9 weeks, which is below the beverage standard. Therefore, the effect which reduces general bacteria is recognized by putting a filling material in a storage tank. Furthermore, by adding the additives, both the cracked stone (particle size 10cm) and the single-grain crushed stone No. 4 are greatly improved to meet the water quality standards, and the single-grain crushed stone No. 4 results in 5 / mL. It became. Therefore, these are recognized as water quality improvement by microorganisms.

  The TOC tends to have a higher removal rate as the particle size is smaller. Also, the value decreases with time. Therefore, it is guessed that the space | gap space | interval has influenced the removal effect. It can be considered that it decreases due to sedimentation or decomposition.

  Hardness, chloride, nitrate nitrogen and nitrite nitrogen tend to increase with time, but only “rainwater” and “mesh” do not change. Finer materials tend to elute. This is related to the surface area of the material, and it is presumed that a material containing a fine material has a large surface property and a large amount of elution. Crusher orchids contain very fine materials and therefore have high elution. None of the ingredients exceed beverage standards.

  “Iron and its compounds” and “turbidity” show very similar behavior. The crusher run shows a very high value, and then the coarse sand shows a high value. The values of other materials are decreasing with time and show extremely small values. The turbidity of crusher orchid and coarse sand is estimated to be derived from iron. Since the iron standard is 2 mg / l or less and the turbidity standard is 2 degrees or less, the crusher run and coarse sand do not meet the beverage standard. The high values of crusher run and coarse sand may be related to the material properties as well as the particle size.

  Only two of the pH values, “rain water only” and “mesh two-stage”, show low pH due to the influence of acid rain, but other than that show weak alkali. This behavior is similar to hardness and is thought to be due to the hydroxylation of minerals, but after 3 weeks it is stable with weak alkali and meets beverage standards.

  From the above, plastic mesh material has almost no water purification effect. On the other hand, it became clear by experiment that the water quality was improved by putting the filling material in the storage tank.

  In particular, with respect to general bacteria, the effect of reducing the general bacteria can be recognized by putting the packing material in the storage tank. Among them, the storage tank filled with single-grain crushed stone No. 4 has very few general bacteria and satisfies the beverage standard.

  Further, the TOC tends to have a higher removal rate as the particle size is smaller. It is thought to be due to sedimentation and microbial purification, and both tanks meet beverage standards.

  Furthermore, the pH of the tank filled with stones makes the acidic water quality weakly alkaline and suitable for beverage standards.

  Hardness and chloride ions tend to increase with time, but only “rainwater” and “mesh” do not change. Finer materials tend to elute. None of the ingredients exceed beverage standards.

  “Iron and its compounds” and “turbidity” show very similar behavior, with a very high crusher run and then a high value for coarse sand. The values of other materials are decreasing with time and show extremely small values.

  For solutes, materials with large particle sizes have low solute mass, and for those where sedimentation and adherent microorganisms are effective, materials with small particle sizes have large effects such as a small sedimentation distance and a large surface area. The behavior of water quality differs depending on the type.

  Among the materials tested this time, it became clear that single-grain crushed stone No. 4 has a medium particle size and meets beverage standards in all items except odor, and is the most suitable material as a filler for rainwater storage tanks. It was. This shows that the settling distance of the void and the surface area of the material were appropriate.

  DESCRIPTION OF SYMBOLS 1 Rainwater storage system, 3 Reservoir tank, 5 Water intake sheath, 7 Pump, 9 Sending part, 11 Sending pipe, 15 Water intake adjustment part, 17 Conduit, 19 Building, 21 Rain gutter, 23 Heat exchange part, 25 Sheet, 27 Crushed stone layer, 29 Backfill soil layer, 33, 37 Water intake position, 35 Inflow position

Claims (2)

A rainwater storage system for storing inflowing rainwater,
A water tank having a crushed stone layer whose side and bottom are impermeable and filled with crushed stone ;
A water intake sheath with a lower end in the crushed stone layer and an upper end above the crushed stone layer;
With a water intake,
The rainwater flows in from the top of the crushed stone layer of the water tank, and is stored in the crushed stone gap of the crushed stone layer by blocking the side and bottom of the crushed stone layer,
The intake section is
By taking the rainwater stored in the crushed stone layer from the upper end of the intake pod using the fact that the lower end of the intake pod is in the crushed stone layer, a flow of water is generated in the crushed stone layer,
The microorganisms are made to survive on the surface of the crushed stone by the flow of water generated in the crushed stone layer, and the water purified by the microorganisms is taken in the crushed stone layer ,
The crushed stone filled in the crushed stone layer is single-grain crushed stone No. 4,
The water taken from the water intake section is a rainwater storage system in which the number of general bacteria is 100 individuals / mL or less . A rainwater storage system for storing inflowing rainwater,
A crushed stone layer filled with crushed stone, and a water storage tank having a water-impervious portion for shielding the side and bottom of the crushed stone layer;
A lower end is in the crushed stone layer, and a water intake portion having a water intake sheath and a pipe whose upper end is above the crushed stone layer,
The rainwater flows in from the top of the crushed stone layer of the water tank, and is stored in the crushed stone gap of the crushed stone layer by blocking the side and bottom of the crushed stone layer,
The intake section is
Taking the rainwater stored in the crushed stone layer from the upper end of the intake pod using the fact that the lower end of the intake pod is in the crushed stone layer, the rainwater flowing into the water storage tank is taken into the crushed stone Water flow in the crushed stone layer by taking water through the layer,
The microorganisms are made to survive on the surface of the crushed stone by the flow of water generated in the crushed stone layer, and the water purified by the microorganisms is taken in the crushed stone layer,
There are a plurality of intake parts,
By changing the amount of water taken by each water intake unit according to the quality of water taken by each water intake unit, the flow of water in the crushed stone layer is changed to change the quality of water taken by each water intake unit. , rain water storage system.