JPH07292727A - Recovery method of water and device therefor - Google Patents

Abstract

PURPOSE:To efficiently recover water in a method for making water flow under negative pressure into a porous tube buried in a medium layer into which water to be recovered is infiltrated, by repeating covering and uncovering of the surface of the medium layer. CONSTITUTION:Water to be recovered is infiltrated into a medium layer, a porous tube 4 is buried in the medium layer, water is let flow under negative pressure in the porous tube 4, and the water infiltrated into the medium layer is passed through the porous tube 4 so as to be recovered. In this method, covering and uncovering of the surface of the medium layer are repeated by means of a covering and uncovering member 16 made of film, sheet or the like having impermeability, according to the quantity of water infiltrated into the medium layer and to be recovered. When this method is applied to the earth 17 as a medium layer, it becomes an effective means for insuring irrigation water or drinking water in a dry zone.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for collecting water and a device therefor.

[0002]

2. Description of the Related Art It is important to obtain good quality water at a low price in arid areas and remote islands from the viewpoint of population growth measures and global environmental conservation. A great deal of effort and ingenuity has been put into using it.
In general, river water flowing through arid areas has a high salt concentration and is often unsuitable for domestic and irrigation water.

As described above, as a method for treating river water or ground water having a high salt concentration and not suitable for direct use as irrigation water, or polluted water requiring purification treatment,
A method of evaporating and collecting water is effective. For example, a solar water purifier is a flat building with a transparent resin plate, sheet, film, glass, etc. as a roof, in which a sheet or dish for storing raw water to be evaporated is placed, and solar water heats it to generate steam, Water is condensed by condensing water vapor into the part corresponding to the transparent roof due to the temperature difference between the building and the outside air, and the condensed water flowing from the roof with a slight slope is collected. There is also a method to collect water in the air by dew condensation using a dehumidifier, but this has been done at the experimental level, but it requires a large amount of power and requires a large amount of irrigation for greening measures in the desert area. Obtaining water requires huge investment and is unlikely to be realistic.

[0004]

However, such a solar water purifier is, of course, a method capable of acquiring water during a period of time when sunlight is radiated, which is a cloudy day or night time. Could not be used for.

The phenomenon that the temperature drops at night and the surface of the earth gets wet with dew condensation water, or the water behind the stones adheres dew condensation water to the surrounding area is also observed in dry areas such as deserts where the annual rainfall is small. Collecting these waters is considered difficult,
The current situation is that they have not been collected in an economically advantageous manner. If left as it is, these moisture cannot be used effectively because they are evaporated by the action of solar heat and wind.

Therefore, the present inventors have utilized a natural phenomenon,
As a result of various studies to effectively obtain the dew that falls at night or early in the morning, an environment where the surface of the medium layer can be covered with a hardly water-permeable film or sheet to prevent the dissipation of water after the dew falls. The water is circulated through the porous tube, which is installed near the surface of the medium layer where the dew is permeating and is always adjusted to a negative pressure, and the water in the medium layer is moved by the negative pressure to make it porous. The present invention has been completed by surprisingly finding that dew can be obtained by collecting the dew through a tube. Originally, it obtains water that evaporates from the ground surface and dissipates as water vapor. It is an effective means for securing irrigation water and drinking water in dry areas such as desert areas where annual precipitation is low. Is.

[0007]

That is, the gist of the present invention is that the water to be recovered is infiltrated into the medium layer, a porous tube is embedded in the medium layer, and a negative pressure is applied to the porous tube. In a method of circulating water and collecting water that has penetrated into the medium layer by passing through the porous tube, a material that is impermeable to water depending on the amount of water to be collected that permeates into the medium layer. The method for recovering water, characterized in that the surface of the medium layer is repeatedly covered or released by the method, and a medium layer into which water to be recovered is infiltrated, is buried in the medium layer, and the water is passed therethrough for recovery. Porous tube, a coating / opening member made of a material that is impermeable to water for preventing water from evaporating from the surface of the medium layer, and water is supplied under negative pressure into the porous tube. It receives the water that flows through the reservoir and the porous pipe that is installed upstream. In recovery apparatus for water consisting comprise that water receiving tank.

The present invention will be described in detail below. First, in the present invention, as the water to be recovered, for example, dew condensation water, rainwater, or water once evaporated in the air is suitable. As the material of the medium layer into which water is allowed to enter, a substance that allows water to easily enter and causes migration of water due to capillarity is particularly preferable. As such a substance, in addition to the earth itself, sand, earth, gravel and other materials that make up the earth can be used as they are, but in addition to this, diatomaceous earth, silica sand, acid clay, silica, alumina, talc, water-absorption having water retention Polymers can be used.

If the water obtained is used as drinking water, it is expedient to use a clean substance as medium.
In the present invention, the surface of these medium layers is covered with a coating / opening member made of a material impermeable to water for preventing evaporation of water from the surface, and the coating or opening of the surface is repeated. It is necessary. The frequency of repetition is not particularly limited, and can be appropriately selected in consideration of weather conditions and the like in order to improve water recovery efficiency.

For example, in the early morning when the temperature of the surface of the earth does not rise, it is desirable to cover the surface of the earth with a covering / opening member such as a water (water vapor) impermeable film or sheet to prevent the dissipation of water. Further, in order to allow water to be absorbed into the medium during a certain period of rainfall, it is desirable to remove the above members and open them, and also remove these during the time period when the temperature of the night falls.

Since the covering / opening work for spreading or withdrawing on the ground is generally performed by winding or spreading, the thickness is preferably such that this operation can be easily performed, preferably 0. The range of 0.1-6 mm is more preferable, and the range of 0.2-4 mm is more preferable. In the present invention, the porous tube is embedded in the medium layer. The depth to be buried is not particularly limited, but usually 1 to 10 from the surface of the medium layer.
0 cm is preferred. If it is too shallow, it is easily affected by the temperature of the surface of the earth, which is disadvantageous for the condensation of water vapor. If it is too deep, a large negative pressure difference must be taken to allow water or water vapor to reach.

[0012] Ceramics, concrete, and porous glass are generally preferable as the material constituting the porous tube, but a porous molded body made of a plastic material such as a metal sintered body, polyethylene, polypropylene, or rubber, and a filter. A material that can be used as a material and that is molded into a tubular shape can be used. A hydrophilic material or a hydrophilized material is preferable from the viewpoint of recovering once evaporated water or water existing in the air. These porous materials have a pore size of 0.01 to 200 μm.
It is desirable to have holes in the range of m. If it is smaller than this, clogging tends to occur during use and the flow resistance of the fluid is large, so the water flowability is poor, and if it is rougher than this, air will flow in. However, it tends to be difficult to maintain the negative pressure. Particularly desirable pore size is in the range of 0.1 to 50 μm,
Those having a narrow pore size distribution are particularly suitable. In particular, a cylinder having a pore diameter of about 10 μm, which is obtained by molding and firing porcelain clay having a large amount of quartz, is preferable.

These porous materials are usually formed into a cylindrical shape and used as a porous tube. The inner diameter, wall pressure, and length are not particularly limited, but if they are too small, the resistance when water flows is large, and if they are too large, a large amount of water is circulated in order to flush out the bubbles generated or mixed in inside. Will be required. Therefore, usually, the inner diameter is 3 to 100 mm, preferably 5 to 50 mm, and the meat pressure is 1 to 30 mm, preferably 3
~ 15mm, length is not particularly limited, but depending on the material, such as ceramics is poor in flexibility and is easily broken by flexural stress. It can also be lengthened to reduce the number of connections. PVC for connecting multiple porous tubes,
It is common to use a tube or piping material such as polyethylene, and it is convenient to use a metal pipe, a pipe connector or the like.

At the time of connection, it is preferable to use a tube or the like having a smooth inside, and to prevent the diameter of the tube from abruptly changing so that pressure loss is unlikely to occur. In the present invention, water is circulated under a negative pressure from the water tank provided upstream of the porous tube into the porous tube. In order to make a negative pressure, generally, for example, a water tank is provided at a position lower than the surface on which the porous pipe is laid, usually 30 cm to 3 m, and the flow of water by a siphon is adjusted, and at the outlet of the pipe, , A method of adjusting the height of the open end tip to adjust the negative pressure and the flow rate of water generated in the pipe, and if a water tank is installed at a position higher than the surface on which the porous pipe is laid, attach a control valve. A method of adjusting the flow of water to a negative pressure is adopted.

In the practice of the present invention, the water in the water storage tank must be of a type suitable for the purpose of collecting raw water.
As the recovery of water according to the present invention progresses, circulating water can be supplied as described later, so there is no need to replenish it from outside the system.
In the present invention, by adopting such a configuration, the water that has entered the medium layer passes through the porous tube and is entrained by the water flowing in the porous tube, and becomes the downstream of the water in the porous tube. It is collected in the water tank provided in this way.

The water receiving tank is arranged at a lower position than the water storing tank, and a necessary amount of water in the water receiving tank can be extracted and used for a desired purpose. At least a part of the water is stored in the water receiving means by the water circulating means. It is supplied to the tank and supplied to the porous tube. The water circulation means is not particularly limited,
A pump or the like is used. It is preferable that the liquid level of the water storage tank be constant for stable operation.

FIG. 1 shows an embodiment of the water recovery apparatus of the present invention, in which a wire net (12) is placed in a dew recovery tank (2).
A space (3) underneath, on which the soil particles (13) of Hyuga mullet are placed, and on top of that a layer of sand (14) is provided, in which the porous tube (4) They are connected in series using a tube (5). Water is circulated from the water storage tank (6) to the porous pipe (4) by a siphon, and the inside of the porous pipe (4) is maintained at a negative pressure. The water discharged to the water receiving tank (7) is circulated to the water storage tank (6) by the pump (8). When a large amount of rainfall imposes a water amount exceeding the water retention amount of the medium layer, the water is stored in the drainage receiver (11) via the drainage pipe (10).

In the present invention, it is not essential to return the water in the water receiving tank to the water storing tank and circulate it, and it is possible to use it once as shown in FIG. 2 (16: covering / opening member),
Further, as shown in FIG. 3, a plurality of the above-mentioned water recovery devices are installed from a high position to a low position, and the water in the water receiving tank at the high position is caused to flow into the water tank of the water recovery device installed at the lower position to It is possible to continuously collect water by utilizing the difference, and it is also possible to combine pumping means such as a pump. In this case, it is particularly convenient for use in a place where there is a difference in height such as a sloping land or a building.

Here, for example, the first-stage water receiving tank and the second-stage water receiving tank may be provided separately, but preferably, as shown in FIG. 3, a tank (15) which also serves as a water receiving tank and a water storage tank. So that
The water receiving tank of the device at the former stage can be configured to be used as a water tank of the device at the latter stage (not necessarily the next stage, but may be the latter stage of the second stage).
FIG. 4 is a schematic view showing an example of an apparatus for collecting dew and / or rainwater that has landed on the ground (17).

[0020]

[Embodiment 1] FIG. 1 shows one embodiment of a water recovery apparatus of the present invention. A metal mesh was laid in the center of a styrofoam container having dimensions of 36 cm in length, 44 cm in width, and 32 cm in height, and a space was formed under the wire mesh. On top of the wire mesh, there is a layer of Hyuga Bora soil grains 4c
It was provided to a thickness of m, and a sand layer having a thickness of about 3 cm was provided thereon. Outer diameter 26 mm, inner diameter 8 mm, length 170
The mm porous ceramic tubes (4) were connected in series using four polyvinyl chloride tubes (5) and placed horizontally. A 12 cm layer of sand was further provided on this. The dew collection device thus obtained has an effective water intake surface area of 1584 cm ² .

Water tank (6) so that the position where the porous tube (4) exists is 30 cm higher than the water surface of the water tank (6).
Adjust the height of. Water is flowed from the water storage tank (6) to the porous pipe (4) by siphoning. The negative pressure inside the porous tube (4) was adjusted by the height of the open end portion. Further, the water in the water receiving tank (7) was pumped by the pump (8) so that the height of the water surface of the water tank was always constant.

The water receiving tank (7) was provided with an overflow port, and a graduated cylinder (9) was installed under the overflow port so that the amount of overflowed water, that is, the amount of acquired water could be read.
The amount of water flowing through the tube was 250 ml / min. On a sunny day, November 28, 1993, a covering / opening member (polyethylene sheet not shown) with a thickness of 0.3 mm was placed at 6 o'clock in the morning at a dew collection device installed outdoors in Nishimatsuura-gun, Saga Prefecture. After putting it on so that it covers the entire device, run it for 24 hours
Obtained 100 g. This means that water was acquired at a rate of 1.8 liter / m ² · day based on the surface area of the ceramic tube.

[0023]

[Example 2] Using the same device as in Example 1, under the same operating conditions, on a cloudy day, on the morning of November 25, 1993, in Nishimatsuura-gun, Saga Prefecture, a dew collecting device installed outdoors was used. A polyethylene sheet with a thickness of 0.3 mm was applied at 8 o'clock so as to cover the entire device, and then it was operated for 10 hours and then 1
The polyethylene sheet was removed for 4 hours, and the system was operated for a total of 24 hours to obtain 245 g of water. This means that water was acquired at a rate of 4.4 liter / m ² · day based on the surface area of the ceramic tube.

[0024]

[Example 3] Using the same apparatus as in Example 1, a recovery experiment in the case of rain was conducted in Nishimatsuura-gun, Saga Prefecture, for three days from December 1 to 3, 1993. The operating conditions were the same as in Example 1. There was 49 mm of precipitation as measured by a rain gauge on December 1, and it was cloudy and sometimes fine weather on December 2 and December 3. On rainy days, the device was left open and the seats were not put on, and on the 2-3 days, the seats were covered only for 10 hours from 8:00 am to 6:00 pm during the daytime. A rainfall of 49 mm corresponds to an amount of 7,762 g, but on December 1, 7,620 g (98.2%) of water was obtained, 225 g of water was acquired on the 2nd, and 90 g of water was acquired on the 3rd. A total of 7,935 g of water was acquired in a day.
The total amount was 7935 ml, which corresponds to 102.2% on the basis of precipitation, and the amount of water present in dew and air was recovered in excess of at least 100%. Then, more dew was collected.

[0025]

[Confirmation of water retention capacity and water recovery rate of apparatus] To examine the water retention capacity of the apparatus used in Example 1, sprinkle 5,000 cc of water on a sunny day with rain and dew, and the porous pipe is The amount of water that was not retained when left for 1 hour with the flow stopped was 1,230 cc (24.6 of the sprinkled amount).
%) Was collected in the drainage receiver (11) through the drainage pipe 10. When it was collected as a negative pressure from one hour later, it was 2
After 4 hours, 3,630 cc of water was recovered. 48 in total
60 cc of water was recovered (97.2%). The amount that could not be recovered due to adhesion to sand or evaporation of water from the surface was 1
It was 40 cc.

Next, on a sunny day, 3,420 cc of water was sprayed with rain and dew while maintaining a negative pressure condition from the beginning, and water was collected for 24 hours. Was 3 cc, and the amount of water recovered through the porous pipe was 3180 cc. A total of 93.1% was recovered. The amount that could not be recovered is 97c
It was c.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a water recovery device of the present invention.

FIG. 2 is a schematic view showing an example of a water recovery device of the present invention.

FIG. 3 is a schematic view showing an example of a water recovery device of the present invention.

FIG. 4 is a schematic view showing an example of a water recovery device of the present invention,
A device for collecting dew and / or rainwater that has landed on the ground.

[Explanation of symbols]

 1 Wire Mesh Support Frame 2 Dew Collection Tank 3 Space 4 Porous Tube 5 Polyvinyl Chloride Tube 6 Water Storage Tank 7 Water Receiving Tank 8 Pump 9 Measuring Cylinder 10 Drain Pipe 11 Drain Receiver 12 Wire Mesh 13 Hydrangea Soil Grain 14 Sand Layer 15 Tank that doubles as a water tank and a water tank 16 Cover / opening member 17 Earth

Claims (4)

[Claims] 1. Water to be recovered is infiltrated into a medium layer, a porous tube is embedded in the medium layer, and water is circulated in the porous tube under negative pressure to infiltrate the water into the medium layer. In the method of recovering by passing through the porous tube, the coating or opening of the medium layer surface with a material impermeable to water is repeated depending on the amount of water to be recovered that enters the medium layer. A method for recovering water, which is characterized by carrying out. 2. A medium layer for infiltrating water to be recovered, a porous tube embedded in the medium layer for allowing the water to pass therethrough, and water for preventing water from evaporating from the surface of the medium layer. A coating / opening member made of a material having poor permeability, a water storage layer provided upstream of the porous tube for supplying water into the porous tube under a negative pressure, and water flowing through the porous tube. A water recovery device having a receiving tank for receiving water. 3. A medium layer for infiltrating water to be recovered, a porous tube buried in the medium layer and allowing the water to pass therethrough, and water for preventing evaporation of water from the surface of the medium layer. A coating / opening member made of a material that is difficult to permeate, a water tank that is provided upstream of the porous tube to supply water under negative pressure to the porous tube, and water that flows through the porous tube. A water recovery device comprising a water receiving tank for receiving water and a water circulating means for supplying water in the water receiving tank to the water storage tank. 4. A medium layer for infiltrating water to be recovered, a porous tube buried in the medium layer and allowing the water to pass therethrough, and water for preventing evaporation of water from the surface of the medium layer. A coating / opening member made of a material that is difficult to permeate, a water tank that is provided upstream of the porous tube to supply water under negative pressure to the porous tube, and water that flows through the porous tube. A water recovery device configured to have a plurality of water recovery devices provided with a water reception tank for receiving water in a multi-stage manner, and the water reception tank of the preceding device can be used as a water tank of the latter device.