CN115135396A

CN115135396A - Stacking type multistage filtering device

Info

Publication number: CN115135396A
Application number: CN202080097283.XA
Authority: CN
Inventors: 小林和由; 江田宪彰; 安仲健二; 西永忠由
Original assignee: Freeway Ltd
Current assignee: Freeway Ltd
Priority date: 2019-12-23
Filing date: 2020-12-22
Publication date: 2022-09-30
Anticipated expiration: 2040-12-22
Also published as: JP7201278B2; WO2021132210A1; CN115135396B; JPWO2021132210A1

Abstract

The invention provides a stacked multistage filtering device which saves space, ensures enough contact time with filtering sand and can improve water quality to a level for beverage application with high efficiency. The stacked multistage filtration device (100) is provided with: the rainwater storage device comprises a first filter tank (20) into which rainwater stored in a rainwater storage container (10) enters, a second filter tank (30) connected to the lower stage of the first filter tank in a manner of being stacked on the first filter tank, a clean water tank (70) which stores purified rainwater filtered by at least the first filter tank and the second filter tank, and a control water tank (80) which receives rainwater from the rainwater storage container, is connected to the clean water tank, and can adjust the water storage capacity of the rainwater storage container and the clean water tank.

Description

Stacking type multistage filtering device

Technical Field

The present invention relates to a filtration technique for storing rainwater in various houses, factories, and the like to be used as drinking water, and more particularly, to a stacked multistage filtration device in which filtration tanks are stacked in multiple stages.

Background

It is known that a certain amount of rainfall occurs within one year in a relatively large number of regions in the world including japan. Such rainwater is basically distilled water in the global water circulation system, and is considered to be safe water with much less impurities and the like than river water, lake water and the like.

Therefore, conventionally, such rainwater is stored and used for domestic water such as washing and bathing (see patent documents 1 to 3).

For example, patent document 1 and other exemplary techniques disclose a method and apparatus for sterilizing or purifying rainwater.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2000-233193

Patent document 2: japanese patent laid-open publication No. 2013-86034

Patent document 3: japanese patent laid-open publication No. 2019-127780

Disclosure of Invention

Problems to be solved by the invention

However, the conventional techniques included in the above patent documents cannot be said to appropriately satisfy the market demand, and there are problems described below.

That is, for example, in patent document 1 or patent document 3, the water is mainly intended for domestic water such as washing and bathing, and it cannot be said that the water is used as drinking water. Accordingly, it is needless to say that there is room for further improvement in order to use the water as drinking water.

In this regard, patent document 2 discloses that the water stored in the secondary water storage tank 13 is made suitable for the beverage by filtering the purified water with the UF filter 16. However, although patent document 2 schematically describes a filter 8 using a sand filter in a slight manner, the scale of the apparatus is still relatively large in view of the separate arrangement of the primary water storage tank 11 and the secondary water storage tank 13.

Here, the sand filtration method adopted in patent document 2 is generally a method of placing a sand filtration tank in a substantially horizontal manner in one stage, and generally requires a large installation area. Further, since the filtration resistance of sand is extremely small, water falling into such a sand filtration tank only falls through the sand filtration material within the area of the falling water. Therefore, the actual effective filtration area is extremely small, only about 0.15% of the installation area. Not only a sufficient filtering performance cannot be expected, but also a filtering time per 1 layer of the filter tank is extremely short, only a few seconds, and it is difficult to secure a sufficient contact time with the filtered sand.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a stacked multistage filtration device which can save space, ensure a sufficient contact time with filtered sand, and efficiently improve water quality to a level for beverage use.

Means for solving the problems

The stacked multistage filtration apparatus according to an embodiment of the present invention is characterized in that,

(1) the device is provided with a first filter tank, a second filter tank, a clear water tank and a control water tank, wherein the first filter tank is provided with: a first water inlet into which rainwater stored in a rainwater storage container enters; first filtered sand that filters rainwater flowing in via the first water inlet; and a first bottom plate supporting the first filtered sand and having a first communication hole formed therein through which filtered rainwater passes, the second filter tank being connected to a lower stage of the first filter tank in a manner of being stacked thereon, and including: a second water inlet through which rainwater passing through the first communication hole enters; second filter sand that filters rainwater flowing in via the second water inlet; and a second floor plate supporting the second filtered sand and having a second communication hole through which filtered rainwater passes, wherein the clean water tank stores purified rainwater filtered by at least the first filter tank and the second filter tank, and the control water tank receives rainwater from the rainwater storage container and guides the rainwater to the first water inlet, is connected to the clean water tank, and is capable of adjusting the water storage capacity of the rainwater storage container and the clean water tank.

In this case, in the stacked multistage filtration device described in the above (1),

(2) preferably, the rainwater collection device further includes a detection tank stacked on the second filtering tank such that the second filtering tank is positioned above the detection tank, and configured to detect the quality of the rainwater passing through the second communication hole.

Further, in the stacked multistage filtration device according to the above (1) or (2),

(3) preferably, the control gutter is divided into a purified rainwater portion into which the purified rainwater flows and a rainwater inflow portion into which rainwater stored in the rainwater storage container flows, and the control gutter further has inflow target switching means for distributing the purified rainwater flowing into the control gutter to the purified rainwater portion and the rainwater inflow portion.

Further, in the stacked multistage filtration device according to the above (3),

(4) preferably, the inflow target switching device distributes the purified rainwater to any one of the purified rainwater part and the rainwater inflow part based on a detection result in a detection tank that detects the quality of the rainwater.

Further, in the stacked multistage filtration device according to any one of the above (1) to (4),

(5) preferably, the rainwater storage device further includes a first sending means for sending the rainwater stored in the rainwater storage container to the control water tank, a second sending means for sending the rainwater stored in the control water tank to the first filtering tank, and a control means for controlling the first sending means and the second sending means, and the control means controls the first sending means and the second sending means so that the rainwater stored in the rainwater storage container circulates from the first filtering tank to the first filtering tank again through the second filtering tank and the control water tank.

Further, in the stacked multistage filtration device according to the above (5),

(6) preferably, the rainwater treatment apparatus further includes a sterilizing unit disposed between the control water tank and the first filtering tank and performing a sterilization treatment of the circulating rainwater.

Further, in the stacked multistage filtration device according to any one of the above (1) to (6),

(7) preferably, the rainwater collecting apparatus further includes at least one additional filtering tank disposed between the second filtering tank and the control water tank, connected to a lower stage so as to be stacked on the second filtering tank, and into which the rainwater having passed through the second communication hole enters.

Further, in the stacked multistage filtration device according to any one of the above (1) to (7),

(8) preferably, one or more minute drain holes different from the first communication hole are formed in a bottom plate of the first filtering tank, and in case an abnormality of the stacked multi-stage filtering device is detected, in order to prevent deterioration, rainwater stored in the first filtering tank is drained by natural flowing down through the minute drain holes without passing through the first communication hole.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the water quality of rainwater stored in a rainwater storage container can be improved to a level suitable for beverage use with high efficiency while saving space and ensuring sufficient contact time with filtered sand.

Drawings

Fig. 1 is a schematic view showing a stacked multistage filtration apparatus according to an embodiment.

Fig. 2 is a schematic view showing the detailed structure of the first filtration tank in the stacked multistage filtration apparatus.

Fig. 3 shows an example of the structure of the partition plate having the overflow dam formed therein in the other mode of the first filtration tank and the perforated support plate in the present embodiment.

Fig. 4 is a schematic diagram showing a detailed structure of a detection water tank in the stacking type multistage filtering device.

Fig. 5 is a schematic diagram showing a detailed structure of a control water tank in the stacked multistage filtering apparatus.

Fig. 6 is a schematic diagram showing an example of the state of an inflow target switching device (switching valve) provided in a control water tank in the stacked multistage filtration device.

Fig. 7 is a configuration example of an image pickup of the stacked multi-stage filter device according to the embodiment.

Fig. 8 is a flowchart illustrating a rainwater filtering method according to an embodiment.

Fig. 9 is a schematic diagram showing a configuration of a first filtering tank 20 according to a modification.

Detailed Description

Next, an embodiment for carrying out the present invention will be described.

[ Stacking type multistage Filter device 100]

Referring to fig. 1 to 7, a stacked multistage filtration device 100 according to the present embodiment will be described. As shown in the drawing, the stacked multistage filtration apparatus 100 has a function of purifying rainwater W stored in the rainwater storage container 10 by rainfall or the like, and includes at least a first filtration tank 20, a second filtration tank 30, a clean water tank 70, a control water tank 80, and a control mechanism CTL. Fig. 7 shows a view obtained by actually assembling the stacked multistage filter device 100 and photographing the same, as a non-limiting example.

Here, the term "rainwater" in the present embodiment includes not only water directly stored in the rainwater storage container 10 by rainfall but also water that has infiltrated into the ground and becomes groundwater or the like. That is, the term "rainwater" in the present embodiment is not particularly limited as long as moisture flowing directly or indirectly into the rainwater storage container 10 is caused on the ground by rainfall.

The rainwater storage container 10 has a function of storing the rainwater W. The rainwater storage container 10 is preferably buried in the ground, for example, but may be installed on the ground. As a specific shape of the rainwater storage container 10, for example, a known storage container having a capacity of several tens to kiloliters or more can be exemplified.

As shown in fig. 2, the first filter tank 20 of the present embodiment is configured to include a first water inlet 21 into which rainwater W stored in the rainwater storage tank 10 flows, first filter sand 22 that filters rainwater W flowing in through the first water inlet 21, and a first bottom plate 23 that supports the first filter sand 22 and has a first communication hole 23a through which filtered rainwater W passes, and the like.

Further, as shown in the figure, the first filtering tank 20 may include: an outer wall 24 erected from the periphery of the first bottom plate 23, a cover member 25 covering the first water inlet 21 along the outer edge of the outer wall 24, and a partition plate 26 partitioning the inside of the first filter tank 20. Thus, the first filtering tank 20 is divided into a filtering area FA and an unused area EA by the partition plate 26.

As shown in fig. 2(b), an overflow dam 26a is formed at the top of the partition plate 26, and when the first filter sand 22 is clogged, for example, rainwater W leaking from the filter area FA through the overflow dam 26a flows into the emergency area EA. In this way, in the present embodiment, water leakage from the filter tank to an undesired area is prevented by the presence of the overflow dam 26a, and water that has passed over the overflow dam 26a flows safely to the next stage via the usual discharge holes (discharge holes 23b and the like). Thus, even if an abnormal situation occurs, water leakage from each groove can be effectively prevented.

In addition, the drain holes 23b are formed in the first bottom plate 23 at the region corresponding to the unusual region EA, and as shown in fig. 1, the rainwater can finally flow back to the rainwater storage container 10. Further, an insertion hole (not shown) into which the flow path L2 can be inserted is formed in the cover 25, whereby rainwater W can flow into the first water inlet 21 even when the cover member 25 is kept.

The rainwater W flowing into the first filtering tank 20 through the flow path L2 flows into the filtering area FA. As described above, the filter area FA is divided by the partition plate 26, and in the divided area, the first filtered sand 22 is supported by the first support plate 27. In the present embodiment, the first filter sand 22 has a double-layer stacked structure of the first filter sand bag 22a and the first filter sand bag 22b, each of which is formed by inserting filter sand into a filter bag having a plurality of micropores formed therein.

The overflow dam 26a of the present embodiment is not limited to the V-shape illustrated in fig. 2(b), and may be, for example, a concave shape as illustrated in fig. 3(a) as long as the function of the dam can be exhibited.

As illustrated in fig. 3(b), a plurality of circular holes 27a are formed in the first support plate 27, and the rainwater having passed through the first filter sand 22 drops downward through the circular holes. In this way, since the first support plate 27 of the present embodiment has the plurality of circular holes 27a, rainwater passing through the first support plate 27 can uniformly drop downward.

Further, in the present embodiment, the outflow regulating member 28 is disposed below the first support plate 27 in the filter area FA.

The outflow adjustment member 28 is composed of a reference plate 28a having a first circular hole formed therein, a slide plate 28b having a second circular hole corresponding to the first circular hole formed therein and slidable in the horizontal direction in contact with the reference plate 28a, and a moving handle 28c capable of moving the slide plate 28b in the horizontal direction.

Accordingly, the user can align the first circular hole and the second circular hole in the vertical direction by moving the moving handle 28c in the horizontal direction. Therefore, if the first circular hole and the second circular hole are at the same position in the vertical direction, the rainwater can flow out downward (toward the second filtering tank 30) through the overlapped circular holes with a throughput of 100%.

In addition, if the first circular hole and the second circular hole are overlapped by half in the vertical direction, rainwater flows out downward through 50% of the overlapped circular holes. In other words, the user can arbitrarily adjust the flow rate of rainwater flowing downward (toward the second filtering tank 30) by moving the moving handle 28c in the horizontal direction.

In addition, in an area corresponding to the filtering area FA among the first bottom plate 23, a first communication hole 23a is formed, and as shown in fig. 1, the rainwater W passing through the first communication hole 23a flows into a second filtering tank 30 which will be described later.

In the present embodiment, the first filtering sand 22 is exemplified by a double-layered structure of the first filtering sand bag 22a and the first filtering sand bag 22b, but the first filtering sand bag 22a may be formed in a single layer, or may be formed by stacking any of three or more layers. As described above, in the present embodiment, the number and quality of the filter material may be selected according to the degree of contamination of raw water (rainwater) to be treated.

In the present embodiment, the first filter sand 22 as the filter material is sand suitable for filtration, but the filter material suitable for the present embodiment is not limited to this sand material. That is, for example, instead of the first filter sand 22, various known filters may be used as the "first filter" (the same applies to other filter tanks).

The second filter tank 30 has a function of being stacked on the first filter tank 20 via a stacking holder 23c formed on the bottom surface of the first bottom plate 23 of the first filter tank 20.

Since the second to fourth lauter tuns 30 to 50 to be described below are substantially the same as the first lauter tun 20 except that the cover member 25 is not provided, corresponding reference numerals are given thereto, and the description thereof will be appropriately omitted.

As shown in fig. 1 and 2, the second filter tank 30 of the present embodiment is connected to a lower stage of the first filter tank 20 in a manner of being stacked on the first filter tank 20, and is configured to include a second water inlet 31, a second filter sand 32, and a second bottom plate 33, the rainwater W passing through the first communication hole 23a enters the second water inlet 31, the second filter sand 32 filters the rainwater W flowing in through the second water inlet 31, and the second bottom plate 33 supports the second filter sand 32 and is formed with a second communication hole 33a through which the filtered rainwater W passes.

Accordingly, the rainwater W flowing from the first filtering tank 20 is purified by removing impurities according to the amount of the first filtering sand 22, compared to when the rainwater W is stored in the rainwater storage container 10.

The third and fourth lauter tuns 40 and 50 have the same configuration as the second lauter tun 30, and therefore, the description thereof is omitted. As described above, in the present embodiment, it is preferable that at least one additional filtering tank is further provided, which is disposed between the second filtering tank 30 and the control water tank 80 to be described later, is connected to a lower stage so as to be stacked on the second filtering tank 30, and the rainwater W passing through the second communication hole 33a enters the additional filtering tank.

In the present embodiment, two tanks, i.e., the third and

fourth lauter tanks

40 and 50, are shown as the additional lauter tanks, but the present invention is not limited to this embodiment. That is, the additional filtration tank of the present embodiment may be a single tank of the third filtration tank 40, or may be configured with an arbitrary number of three or more tanks.

In the present embodiment, the filter sand provided in each filter tank has a two-layer structure, but the number of layers of filter sand may be different in at least a part of each tank (for example, two layers of the first filter sand pack 22a and the first filter sand pack 22b in the first filter tank 20, and a single layer of the second filter sand pack 32a in the second filter tank 30).

The detection water tank 60 is stacked on the second filtering tank 30 or the like such that the second filtering tank 30 or the like is positioned on the upper side (upper side in the vertical direction), and has a function of detecting the quality of the rainwater W passing through the second communication hole 33a or the like.

More specifically, as shown in fig. 4, the detection water tank 60 of the present embodiment includes: a water quality detecting means 61 for detecting the water quality of the rainwater W, a cartridge frame 62 for housing the water quality detecting means 61, and support legs 63 disposed in the cartridge frame 62 and supporting the water quality detecting means 61.

In the present embodiment, since the two lauter tuns (the third lauter tun 40 and the fourth lauter tun 50) are further provided as additional lauter tuns, the fourth lauter tun 50 is placed directly above the detection water tank 60 as shown in fig. 1 and the like.

Accordingly, the rainwater W flowing into the detection tank 60 (water quality detection mechanism 61) through the fourth filter sand 52 and the first communication hole 53a in the fourth filter tank 50 is sent out from the discharge port 61a of the water quality detection mechanism 61 to the control tank 80 through the flow path L3. A circular hole 62b through which the flow path L3 can pass is formed in the side wall of the cartridge frame 62.

On the other hand, the structure is as follows: when rainwater W overflows from the water quality detection mechanism 61 due to a failure or the like in the water quality detection mechanism 61, the overflowing rainwater W flows along the outer wall of the water quality detection mechanism 61, and finally flows back to the rainwater storage container 10 from the emergency drain port 62a via the flow path L4. Thus, even if water leaks from the detection water tank 60, the water can be drained through the emergency drain port 62a, and therefore, the leakage and spread to the periphery of the detection water tank 60 can be suppressed.

As a specific example of the water quality detection means 61 for detecting the water quality of the rainwater W, various sensors capable of detecting known evaluation parameters can be used. In the present embodiment, as known sensors constituting the water quality detection means 61, a sensor S1 capable of detecting the hydrogen ion concentration of the rainwater W, a sensor S2 capable of detecting the conductivity of the rainwater W, a sensor S3 capable of detecting the turbidity of the rainwater W, and a sensor S4 capable of detecting the temperature of the rainwater W are used.

The clean water tank 70 has a function of storing the purified rainwater filtered in at least the first filtering tank 20 and the second filtering tank 30. Since the additional filtering tank is provided as described above, in the present embodiment, the rainwater W is filtered by the first to fourth filtering tanks 20 to 50.

Here, the "purified rainwater" refers to rainwater, of which the quality is improved by the filter tanks (in this example, the four filter tanks) among rainwater stored in the rainwater storage container 10.

As shown in fig. 1, the clean water tank 70 of the present embodiment communicates with the outflow hole 85 of the control water tank 80 via the inflow hole 71 formed in the side wall and the flow path CR. Thus, the purified rainwater stored in the control tank 80 can be sent to the clean water tank 70 through the flow path CR. Further, a known pump may be provided in the flow path CR or the like to send the purified rainwater from the control tank 80 to the clear water tank 70.

The flow path L6 is connected to the clean water tank 70. The purified rainwater stored in the clean water tank 70 through the flow path L6 is used as domestic water such as drinking water from the tap K. The domestic water fed from the faucet K is discharged from the water tank S through the flow path L7, for example.

In this case, a water purifier PF may be further provided in the flow path L6. As such a water purifier PF, a known water purifier using a filtration system realized by a known filter such as a fiber, activated carbon, or RO membrane can be exemplified.

The control water tank 80 receives rainwater W from the rainwater storage container 10, guides the rainwater W to the first water inlet 21, is connected to the clean water tank 70, and has a function of adjusting the water storage amount of the rainwater storage container 10 and the clean water tank 70.

More specifically, the control water tank 80 of the present embodiment includes, as shown in fig. 5 and the like: the above-described box frame 81 having the outlet hole 85 formed in the side surface thereof, the cover member 86 covering the box frame 81, and the inflow target switching device 87 for switching the inflow target of rainwater flowing into the controlled water tank 80.

The control water tank 80 is divided into at least a purified rainwater portion 82 into which the purified rainwater PW flows and a rainwater inflow portion 83 into which the rainwater W stored in the rainwater storage container 10 flows. The control water tank 80 of the present embodiment further includes an emergency drain 84 into which rainwater leaked from the upstream portion (each of the filtering tanks and the detection water tank) or the control water tank 80 flows, in addition to the above, and is divided into three sections in total.

As seen from fig. 5, in the cartridge frame 81,

partition walls

81a and 81b are provided upright from the bottom surface, the purified rainwater portion 82 and the rainwater inflow portion 83 are partitioned by the partition wall 81a, and the rainwater inflow portion 83 and the emergency drainage portion 84 are partitioned by the partition wall 81 b.

As shown in the drawing, new rainwater W can be supplied from the rainwater storage container 10 to the rainwater inlet 83 via the flow path L1. Further, a second delivery mechanism P2 such as a known pump is disposed in the rainwater inlet portion 83, and the rainwater W stored in the rainwater inlet portion 83 can be delivered to the above-described filtering tank (first filtering tank 20) through a flow path L2 connected to the second delivery mechanism P2.

Further, a drain port into which rainwater can flow is formed in the bottom of the emergency drain portion 84, and rainwater leaking as described above is returned to the rainwater storage container 10 via the flow path L5 connected to the drain port.

The rainwater purification unit 82 and the rainwater inflow unit 83 in the control tank 80 are provided with water level sensors H1 to H3. This enables the inflow target switching device 87 to be controlled based on the water level values of the water level sensors H1 to H3.

The inflow target switching device 87 has a function of distributing the purified rainwater flowing into the control water tank 80 to the purified rainwater portion 82 and the rainwater inflow portion 83. More specifically, as shown in fig. 5, the inflow target switching device 87 of the present embodiment is constituted by a known switching valve capable of switching the outflow direction, and is disposed on the partition wall 81 a.

This makes it possible to easily distribute the rainwater that has flowed into the control water tank 80 from the upstream portion (the first filtering tank 20, the second filtering tank 30, or the like) described above through the flow path L3 to the purified rainwater portion 82 and the rainwater inflow portion 83.

Further, it is preferable that the inflow target switching device 87 (switching valve) in the present embodiment distributes the purified rainwater to either one of the purified rainwater portion 82 and the rainwater inflow portion 83 based on the detection result in the detection water tank 60 for detecting the quality of rainwater described above. That is, it is assumed that the quality of rainwater cannot be sufficiently improved by only one round, depending on the initial quality of rainwater or the purification performance of the filter tank.

Therefore, as shown in fig. 6(a), if it is determined that the water quality has reached a predetermined standard (for example, a standard that can be used for domestic water as described above) based on the detection result obtained from the detection water tank 60, the inflow target switching device 87 is set to the side of the rainwater purification unit 82 under the control of the control means CTL to be described later.

On the other hand, as shown in fig. 6(b), if it is determined that the water quality does not meet the predetermined standard based on the detection result obtained from the detection water tank 60, the inflow target switching device 87 is set to the rainwater inflow portion 83 side under the control of the control means CTL.

Thus, for example, if the inflow target switching device 87 is set to the rainwater inflow portion 83 side, rainwater can be circulated through the filter tank and the control water tank via the flow path L2 and the flow path L3 described above and the second delivery mechanism P2 (pump and the like). The rainwater flowing from the rainwater storage container 10 into the control water tank 80 can be circulated at least twice or more in the filtering tank, and the water quality is improved accordingly.

Accordingly, the "purified rainwater" in the present embodiment may be water in which the rainwater W stored in the rainwater container 10 passes through the filtering tank at least once. That is, the purified rainwater means water having a water quality according to the respective purposes of use, and rainwater passing through the filter tank only once circulates, and water passing through the filter tank multiple times is treated as "purified rainwater" in the same manner.

In addition, when the circulation system of the rainwater is configured, the stacked multistage filtration device 100 of the present embodiment preferably includes: first delivery means P1 for delivering rainwater W stored in rainwater storage container 10 to control water tank 80, second delivery means P2 for delivering rainwater W stored in control water tank 80 to the upstream part (first filtering tank 20), and control means CTL for controlling first delivery means P1 and second delivery means P2.

Further, the control means CTL preferably controls the first feeding means P1 and the second feeding means P2 so that the rainwater W retained in the rainwater retaining container 10 is circulated again from the first filtering tank 20 to the upstream portion (the first filtering tank 20, etc.) through at least the second filtering tank 30 and the control water tank 80.

As shown in fig. 1, the stacked multistage filtration device 100 of the present embodiment preferably further includes a sterilization mechanism 90, and the sterilization mechanism 90 is disposed between the control water tank 80 and the upstream portion (the first filtration tank 20, etc.) described above, and performs sterilization treatment of circulating rainwater. This makes it possible to sterilize and disinfect various bacteria such as bacteria in rainwater.

Specific examples of the sterilization means 90 include a known UV irradiation device that sterilizes by ultraviolet rays and an electron beam irradiation device that sterilizes by electron beams, which can be attached to the flow path L2.

In the present embodiment, as the sterilization means 90, a UV irradiation device is disposed in the flow path L2, but a light irradiation device for irradiating electromagnetic waves having different wavelengths may be disposed in series in the flow path L2. Further, control means CTL described later may be configured to adjust the irradiation intensity of sterilization means 90 based on the result of the water quality detection of rainwater obtained from detection water tank 60.

The control mechanism CTL is electrically connected to the detection water tank 60, the control water tank 80, or the sending-out mechanism, and has a function of generally controlling the stacked multistage filtration apparatus 100 to perform the above-described various functions. The control means CTL may be exemplified by a known computer equipped with a storage means such as an arithmetic unit or a memory.

[ method of filtering rainwater Using Stacking-type multistage Filter device 100]

Next, a method of filtering rainwater using the stacked multistage filtering device 100 according to the present embodiment will be described with reference to fig. 8.

First, in step 1, the inflow destination switching device 87 is controlled to switch the inflow destination so that the water having passed through the filtration tank flows into the control water tank 80. Thereby, it is set such that rainwater circulates in a circulation system including a filter tank in the stacked multistage filtering apparatus 100.

Next, in step 2, the power supply of each sensor is turned on so that the water levels of the rainwater storage container 10 and the control water tank 80 can be detected. Although not shown, various known water level sensors including a simple float-type water level gauge may be used as the water level sensors H1 to H3 for controlling the water tank 80.

Next, in step 3, the control means CTL determines whether or not there is water flowing only through the circulation system in the control water tank 80. Specifically, the control means CTL determines whether or not water is present in the rainwater inflow portion 83 of the control water tank 80, for example, by using the water level sensor H2. In step 3, the water level (or the amount of water) sufficient for circulating the rainwater may not necessarily be in a state close to the full water state, and may be set to an arbitrary amount of water according to the frequency of use of the purified rainwater PW from the clean water tank 70.

If there is not enough water in the control water tank 80 in step 3 (no in step 3), it is determined whether or not there is water in the rainwater storage 10 in step 4-1. Although a predetermined amount of rainwater is stored in the rainwater storage container 10 due to the supply of water from rainfall or groundwater, it is also conceivable that water is not stored in the rainwater storage container 10 due to the influence of, for example, dry seasons or the like.

Accordingly, if it is determined in step 4-1 that there is no water in the rainwater storage tank 10 (no in step 4-1), the control unit CTL outputs a video for calling attention to a display or the like not shown in the figure, or a warning for calling attention or the like by sound from a speaker not shown in the figure (step 4-2). In such a case, at the current time, the process cannot be performed, and the process is ended.

If it is determined in step 4-1 that there is water that can be supplied to the rainwater storage container 10 (yes in step 4-1), the rainwater before purification is pumped up from the rainwater storage container 10 to the control water tank 80 (step 4-3). Specifically, as step 4-3, the control means CTL delivers the rainwater W from the rainwater storage container 10 to the rainwater inflow portion 83 of the control water tank 80 via the first delivery means P1 and the flow path L1.

After step 4-3, if the water is pumped up to the control water tank 60 in step 4-4, the control means CTL performs control for forcibly zeroing the elapsed time of the cycle.

Further, after step 4-4, the flow control device returns to step 1, and changes the set inflow target so that the water circulating in the control water tank 80 flows in by the inflow target switching device 87 (when the inflow target is on the control water tank 80 side, the state is maintained). In this way, when the rainwater W is pumped up from the rainwater storage container 10 to the control water tank 80, since the rainwater W before purification is mixed into the circulation system again, the inflow target switching device 87 switches the inflow target to the control water tank 80 side through the control in step 1.

On the other hand, in step 3, when there is sufficient water in the control water tank 80 (yes in step 3) or after the above-described step 4-3, the circulation of the rainwater W is performed between the control water tank 80 and the multistage filtering tank (step 5). More specifically, as step 5, the control means CTL performs control of supplying the water reserved in the control water tank 80 to the first filtering tank 20 through the flow path L2 by way of the second supply means P2 (pump). In this case, when the sterilizing means 90 is provided in the flow path L2, the control means CTL preferably controls the sterilizing means 90 to sterilize the circulating rainwater. This enables bacteria such as bacteria in rainwater to be removed or sterilized.

Since the control water tank 80 is filled with water through the above step 5, water is always circulated in the circulation system through the second water supply mechanism P2.

Next, at step 6, it is judged whether or not the water in the control water tank 80 is full. More specifically, the control means CTL performs control of detecting whether or not the rainwater inflow portion 83 is full of water based on the detection result of the water level sensor H1, for example.

When it is determined in step 6 that the control water tank 80 is full of water (yes in step 6), the control means CTL performs control to stop the pumping of the rainwater from the rainwater storage tank 10 to the control water tank 80 via the first delivery means P1.

Next, at step 7-2, the control means CTL performs control for initializing measurement of the cycle time by using a known timer means (not shown) such as a timer. That is, since no new water is pumped up from the rainwater storage 10 after step 7-1, a process of returning the value of the timer to the initial value is performed for the purpose of seeking integration of the purification time.

If it is determined at step 6 that the water in the control water tank 80 is not full (no at step 6) or after the elapse of step 7-2, the control means CTL starts the measurement of the cycle time by the timer means (step 8). Thus, the quality of the rainwater W from the rainwater storage container 10 is improved by circulating water between the control water tank 80 and the filtering tank for a predetermined time. The cycle time required for purification can be appropriately set according to the water quality such as the turbidity of the rainwater W on the land.

Then, in step 9, the quality of the rainwater that has passed through the filtering tank is detected in the detection water tank 60, and it is determined whether or not the rainwater meets a desired water quality standard. As an example, in the present embodiment, the following water quality standards can be exemplified.

Hydrogen ion concentration (pH): 5.8-8.6

Conductivity (S/m): 1 to 30

Turbidity (kaolin standard): 1.0 degree or less

Temperature (° c): 5 to 40

The above is an example, and the water quality standard may be used based on, for example, the tap water method.

If it is determined in step 9 that the circulating rainwater meets the desired water quality standard (yes in step 9), it is determined in step 10 whether or not the circulation time has reached a predetermined time. On the other hand, if it is determined in step 9 that the rainwater does not meet the desired water quality standard (no in step 9), the routine returns to step 2 to continue the various processes again.

Next, at step 10, it is determined whether or not the counted time (time during which rainwater W circulates) of the timer means has reached a predetermined time, and when the counted time has reached the predetermined time, the routine proceeds to step 11. When it is determined in step 10 that the counted time has not reached the predetermined time (no in step 10), the process returns to step 2, and the various processes described above are continued again.

When the criteria for water quality detection and the conditions for elapsed time in steps 9 and 10 are respectively satisfied, that is, when the rainwater having passed through the filtering tank has been improved in quality as desired, the control means CTL controls the inflow target switching device 87 to switch the inflow target to the rainwater purification unit 82 communicating with the clean water tank 70 (step 11). By providing steps 9 and 10 in this way, if these conditions are not met, the circulation of the rainwater is maintained between the control water tank 80 and the filtering tank.

Thus, the water purified by the stacked multistage filtering apparatus is stored in the clean water tank 70 through step 11.

Next, in step 11, it is detected whether or not the clean water tank 70 is full of water. More specifically, the control mechanism CTL may determine whether the water level of the clean water tank 70 reaches a prescribed level based on a detection result of a water level sensor (not shown in the figure) provided to the clean water tank 70. As the water level sensor provided in the clean water tank 70, various known water level sensors can be used, as in the other water level sensors described above.

If the clean water tank 70 is not full of water in step 11 (no in step 11), the process returns to step 2 to continue the above-described various processes again, whereas if the clean water tank 70 is full of water (yes in step 11), the process proceeds to step 12.

That is, in step 13, if the clean water tank 70 is full of water, the purified rainwater PW overflows to the control water tank 80 (for example, from the purified rainwater portion 82 to the rainwater inflow portion 83).

In step 13, for example, a bank similar to the overflow bank 26a of the above-described partition plate 26 may be formed at the upper end of the partition wall 81 a. Thus, if the clean water tank 70 and the purified rainwater portion 82 of the control water tank 80 are in a full state, the purified rainwater overflows from the overflow bank located at the upper end of the partition wall 81a toward the rainwater inflow portion 83. In the case where such an overflow dam is provided, it is not necessary to provide a water level sensor in the clean water tank 70, and it may be omitted as appropriate. On the other hand, when the clean water tank 70 is provided with a water level sensor, the control means CTL may perform such control as: when the overflow is detected, if the pumping of water from the rainwater storage container 10 to the control water tank 80 is performed, the pumping of water is stopped.

The overflow from the clean water tank 70 to the control water tank 80 in step 13 is not limited to the above-described embodiment, and for example, a pump (not shown) may be further provided to control the pump to forcibly drain the purified rainwater 82 toward the rainwater inflow portion 83.

After the above step 13, the process returns to step 2, and the above various processes are continued again.

The rainwater filtration method described above may be continuously and circularly performed even at night when domestic water is used relatively rarely. By setting such a night mode, for example, the first and second feeding means P1 and P2 (respective pumps) in the control water tank 80 and the rainwater storage container 10 are always activated at night, and even if the water in the control water tank 80 overflows, the first and second feeding means can be continuously activated without stopping the supply, and sterilization and filtration of the entire water in the water tank can be performed.

< difference between the present embodiment and the conventional method >

In a large-sized, horizontal sand filtration tank system which has been widely used in the past, a large-scale land is required because the arrangement thereof occupies a large area of the filtration tank.

In contrast, according to the stacked multistage filtration apparatus of the present embodiment, a method of continuously circulating rainwater in a filtration tank system by stacking a filtration tank on the top and circulating the rainwater as many times as necessary is adopted, so that space can be saved, a sufficient contact time with filtered sand can be secured, and the quality of rainwater stored in a rainwater storage container can be improved to a level for beverage use with high efficiency.

In addition, in the present embodiment, since rainwater in the filtration tank system can be continuously circulated a plurality of times, in this case, it is possible to secure a sufficient passage time of the filtration material required for capturing solid matter in water, and further, since stacking is performed in a space-saving manner, the apparent area of the sand filtration material is dramatically increased, and thus, a large improvement in filtration performance of the filtration material can be expected.

In addition, when maintenance such as maintenance and management of the filtration tanks is taken into consideration, since a plurality of filtration tanks are stacked, the mass of one filtration tank is not so heavy, and individual filtration tanks can be replaced one by one as necessary, and therefore, improvement in maintenance performance can also be expected.

In the present embodiment, for example, during the continuous circulation, the control means CTL performs output control of the respective delivery means (pumps) to adjust the amount of rainwater discharged from the bottom of the respective filter tanks, thereby constantly positioning the level of rainwater in the filter area FA at the upper portion of the respective filter sands. This can solve the problem of a so-called channel (also referred to as channeling) which has been feared in the past, and can meaningfully utilize the entire area in which the filter tank is installed to each corner.

The embodiment described above is one preferable mode for carrying out the present invention, and the present invention is not limited to this, and the configuration thereof can be modified as appropriate without departing from the gist of the present invention.

< modification example >

Next, a preferred modification of the present invention will be described.

That is, in the above embodiment, as a method of adjusting the outlet flow rate of the rainwater in each filtering tank, a method of opening a hole in the bottom of the filtering tank and adjusting the opening degree of the hole (adjusting the overlapping degree of the first circular hole and the second circular hole in the vertical direction by the moving handle 28 c) is adopted.

According to this method, if the initial value is determined by adjustment at 1 degree at the time of setting, even if the water level rises, it is hydrodynamically the drain flow rate increases and the water level falls. The water level in the filtering area FA is theoretically kept constant by the effect of this negative feedback, but in actual operation, the water level slightly fluctuates up and down due to a delay in this negative feedback.

Therefore, in the present modification, since the water level adjustment by the initial setting is not necessary, a structure for keeping the water level constant by the overflow type is created. The same reference numerals are used for the same components as those of the above-described embodiment, and the description thereof will be appropriately omitted.

That is, as shown in fig. 9, the first filtering tank 20 according to the modification is provided with a spill-type water level adjusting means 29.

The water level adjusting means 29 is a double pipe composed of an outer pipe 29a and an inner pipe 29b, and rainwater W flows in from a gap between the outer pipe 29a and the inner pipe 29 b. More specifically, the rainwater W having passed through the first filtered sand 22 disposed in the filtering area FA flows from the bottom into the gap between the outer pipe 29a and the inner pipe 29b through the first supporting plate 27. When the inflow rainwater W reaches the height of the inner pipe 29b, the inflow rainwater falls down in the inner pipe 29 b.

At this time, since the bottom of the inner pipe 29b is connected to the first communication hole 23a, the rainwater W flowing through the inner pipe 29b flows out to the downstream side (the second filtering tank 30) through the first communication hole 23 a. Thus, in the filter area FA, the water level can be made constant (the same as the opening height of the inner pipe 29 b) at all times based on the installation height of the inner pipe 29 b.

As shown in the drawing, one or more minute discharge holes 23d are formed in the first bottom plate 23. The minute discharge holes 23d are set to have a hole diameter (e.g., a diameter of 2mm in this example) for discharging water at a flow rate that does not affect the constant water level.

In this modification, the following application can be also performed.

That is, when the control means CTL detects an abnormality in the operation of the stacked multistage filtering device (for example, a decrease in the flow rate due to a failure of the pump, a water leak in the circulation system, or a decrease in the power required to operate the electrical system constituting the stacked multistage filtering device 100), the control means CTL stops the operation of all the electrical systems. In this way, when the system is stopped urgently when an abnormality occurs, in the system constituting the conventional filtration tank, rainwater stored in each tank remains unchanged, and bacteria and the like may propagate.

In contrast, according to the present modification, since the first communication hole 23a and the minute discharge holes 23d are formed in the first bottom plate 23, respectively, the water amount balance of the rainwater circulating in the filtering tank can be as follows.

"the amount of water flowing from the flow path L2 into the first filter tank 20" + "the amount of water passing through the first communication hole 23 a" + "the amount of water passing through the fine discharge holes 23 d"

Here, in the case where the amount of water passing through the first communication hole 23a is very much larger than the amount of water passing through the fine discharge holes 23d (the amount of water passing through the first communication hole 23a > > the amount of water passing through the fine discharge holes 23 d), the water level in the filtering area FA of the first filtering tank 20 can be maintained even in the above-described continuous operation. On the other hand, when the vehicle is stopped suddenly due to the abnormality, the water can be reliably discharged from the small discharge holes 23d to the downstream side by a small amount without passing through the first communication hole 23 a.

In other words, in the first bottom plate 23 of the first filter tank 20 of the present modification, one or more minute drain holes 23d different from the first communication hole 23a are formed, and when the abnormality described above with respect to the stacked multistage filter device 100 is detected, the rainwater stored up to now in the first filter tank 20 is drained by natural flow down through the minute drain holes 23 a.

Therefore, even when the vehicle is stopped in an emergency, rainwater is prevented from staying in each of the filter tanks for a long time. In such an emergency stop, the filtering area FA is free from rainwater and only filters sand, and thus the filtering area FA can function as a drainage device in an emergency.

Although the first filtering tank 20 has been described above, the minute discharge holes 23d having such a function are not limited to the first filtering tank 20, and may be provided in at least one of the second filtering tank 30, the third filtering tank 40, the fourth filtering tank 50, the detection water tank 60, the clean water tank 70, and the control water tank 80, for example.

Industrial applicability of the invention

As described above, the stacked multistage filtration apparatus according to the present invention can contribute to providing a filtration apparatus which can save space, ensure sufficient contact time with filtered sand, and improve water quality efficiently.

Description of the reference numerals

100 stacking type multistage filtering device

10 rainwater storage container

20 first filtering tank

30 second filtering tank

40 third filtering tank

50 fourth filter tank

60 detection water tank

70 clear water tank

80 control water tank

90 sterilizing mechanism

CTL control mechanism

Claims

1. A stacked multistage filtering device is characterized in that the device is provided with a first filtering tank, a second filtering tank, a clear water tank and a control water tank,

the first filter tank is equipped with: a first water inlet into which rainwater stored in the rainwater storage container enters; first filter sand that filters rainwater flowing in via the first water inlet; and a first base plate supporting the first filtered sand and formed with a first communication hole through which filtered rainwater passes,

the second filtering tank is connected to the lower stage of the first filtering tank in a manner of being stacked on the first filtering tank, and is provided with: a second water inlet through which rainwater passing through the first communication hole enters; second filtered sand filtering rainwater flowing in through the second water inlet; and a second bottom plate supporting the second filtered sand and formed with second communication holes through which filtered rainwater passes,

the clean water tank stores purified rainwater filtered by at least the first filtering tank and the second filtering tank,

the control water tank receives rainwater from the rainwater storage container, guides the rainwater to the first water inlet, is connected to the clean water tank, and can adjust the water storage capacity of the rainwater storage container and the clean water tank.

2. A stacked multistage filtration device according to claim 1, further comprising a detection water tank which is stacked on the second filtration tank such that the second filtration tank is positioned on the upper side, and which detects the quality of rainwater passing through the second communication hole.

3. The stacked multistage filtering device as defined in claim 1 or 2, wherein the control gutter is divided into a purified rainwater portion into which the purified rainwater flows and a rainwater inflow portion into which rainwater stored in the rainwater storage container flows,

the control tank further has an inflow target switching device for distributing the purified rainwater flowing into the control tank to the purified rainwater portion and the rainwater inflow portion.

4. A stacked multistage filtering device according to claim 3, wherein said inflow target switching device distributes the purified rainwater to either one of the purified rainwater portion and the rainwater inflow portion based on a detection result in a detection tank that detects the quality of the rainwater.

5. A stacked multistage filtration device according to any one of claims 1 to 4, wherein:

a first sending-out mechanism that sends out the rainwater stored in the rainwater storage container to the control water tank;

a second sending-out mechanism that sends out the rainwater stored in the control water tank to the first filtering tank; and

a control means for controlling the first feeding means and the second feeding means,

the control means controls the first and second sending means so that rainwater stored in the rainwater storage container is circulated again from the first filtering tank to the first filtering tank via the second filtering tank and the control water tank.

6. A stacked multistage filtration apparatus according to claim 5, further comprising a sterilization mechanism which is disposed between said control water tank and said first filtration tank and performs sterilization treatment of said rainwater in circulation.

7. A stacked multistage filtering apparatus according to any one of claims 1 to 6, further comprising at least one additional filtering tank disposed between the second filtering tank and the control water tank, connected to a lower stage so as to be stacked on the second filtering tank, and into which rainwater passing through the second communication hole enters.

8. The stacked multistage filtering apparatus as claimed in any one of claims 1 to 7, wherein one or more minute discharge holes different from the first communication hole are formed in a bottom plate of the first filtering tank,

in the case where an abnormality is detected with respect to the stacked multistage filtering device, in order to prevent deterioration, the rainwater stored in the first filtering tank is drained by natural flowing down through the minute drain holes without passing through the first communication holes.