JP3429385B2 - Seawater desalination equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seawater desalination apparatus for desalination of seawater.

[0002]

2. Description of the Related Art Conventionally, there has been a demand for desalination of seawater to ensure a stable supply of fresh water. Furthermore, there is also a demand to establish a so-called self-sustaining system that desalinates seawater using only solar energy. Therefore, in order to meet such a demand, conventionally, there is a basin-type seawater desalination apparatus utilizing solar energy, which will be briefly described below.

As shown in FIG. 5, this seawater desalination apparatus 100 has a basin (basi) such as a tank having a large area.
n) 102. Below the bottom of the basin 102,
A heat insulating layer 104 (or dry sand) is provided. Therefore, the bottom surface of the basin 102 has a black color. A salt water supply port 106 is provided on one side of the basin 102, and seawater is supplied from the salt water supply port 106 into the basin 102.

Above the above-mentioned basin 102, a frame 108 assembled like a house is installed. A transparent cover 110 made of glass or the like is stretched over the roof of the frame 108. Also, the frame 108
In the state in which the is installed, side grooves 112 are provided between both side portions of the frame 108 and both side portions of the basin 102, respectively. Both side grooves are communicated with each other, and one side groove 112 is provided with a fresh water outlet 114.

With the above structure, when the basin surface (black) of the basin 102 absorbs solar heat, the seawater stored inside is heated and evaporated. The vaporized water vapor rises and reaches the glass surface of the transparent cover 110. The water vapor that reaches the glass surface is cooled by the outside air, condenses, and flows down along the roof slope. As a result, water droplets are formed on the gutter 1.
Water is collected in 12 and taken out from the fresh water outlet 114.

When the above steps are repeated, the seawater level in the basin 102 is lowered by the amount of the evaporated water and the salt concentration is increased. Therefore, when the water level reaches a certain level, the brine discharge pipe 11 communicated with the bottom of the basin 102.
High-concentration seawater is discharged from 6, and seawater is newly supplied into the basin 102 from the salt water supply port 106.

[0007]

However, the above-mentioned basin-type seawater desalination apparatus utilizing solar energy 10 is used.
In the case of 0, there is a problem that the water production efficiency is low because the heat loss due to heat radiation to the surroundings due to the structure is large and the utilization efficiency of the heat used for desalination is low. For this reason, conventionally, the area of the basin 102 is increased to compensate for the low efficiency of water production.

In view of the above facts, the present invention has an object to obtain a seawater desalination apparatus capable of improving the efficiency of water production.

[0009]

The seawater desalination apparatus according to the present invention as set forth in claim 1 uses the sunlight that is lit as a heat source to turn the seawater stored in the basin into warm seawater and to generate steam. First seawater desalination means for collecting and collecting water droplets generated by condensing generated steam, and cold seawater feeding means for arranging a hydrophobic porous membrane on the bottom surface of the basin and further feeding cold seawater therebelow And a second seawater desalination means for collecting and collecting water droplets generated by condensation on the surface of the cold seawater feeding means due to the temperature difference between the warm seawater and the cold seawater.

A seawater desalination apparatus according to a second aspect of the present invention includes a daylighting body which is arranged in an inclined state and which shines sunlight.
A basin that is placed below the lighting body to store warm seawater heated by the sunlight that is lit and to generate steam, and a water droplet generated by condensation of the steam generated in the basin on the surface of the lighting body. A first seawater desalination unit configured to include a first water collection unit that collects water, and a first water intake unit that collects fresh water collected in the first water collection unit,
The hydrophobic porous membrane arranged on the bottom surface of the basin, the cold seawater feeding means arranged below the hydrophobic porous membrane for feeding cold seawater, and the water droplets condensed on the surface of the cold seawater feeding means A second seawater desalination unit configured to include a second water collection unit for collecting water and a second water intake unit for collecting fresh water collected in the second water collection unit. I am trying.

According to a third aspect of the present invention, in the seawater desalination apparatus according to the second aspect, the first seawater desalination means and the second seawater desalination means are unitized. Is characterized by.

A seawater desalination apparatus according to a fourth aspect of the present invention is the seawater desalination apparatus according to any one of the first to third aspects, in which warm seawater stored in the basin is circulated by a circulation pipeline. The feature is that

[0013]

According to the first aspect of the present invention, first, the seawater stored in the basin is turned into warm seawater by the first seawater desalination means by using the sunlight that is collected as a heat source. At this time, part of the warm seawater becomes steam. The generated water vapor is condensed into water droplets, and the water droplets, that is, fresh water, are collected and taken.

On the other hand, a hydrophobic porous membrane is arranged on the bottom surface of the basin, and cold seawater feeding means for feeding cold seawater is further provided below it. Therefore, water vapor is generated and moves due to the temperature difference between the warm seawater and the cold seawater, and is condensed on the surface of the cold seawater feeding means and adheres as water drops. And
This water drop, that is, fresh water, is collected and taken.

That is, according to the present invention, not only fresh water is taken in by the first seawater desalination means, but also fresh water is taken in by the second seawater desalination means. Therefore, the efficiency of water production is improved.

According to the second aspect of the present invention, first, the sunlight is lit by the lighting body of the first seawater desalination means. A basin is arranged below the daylighting body, and the seawater stored in the basin is heated by the sunlight to be turned into warm seawater. At this time, part of the warm seawater stored in the basin becomes steam. The generated water vapor is condensed on the surface of the daylighting body arranged in an inclined state to form water droplets. The water droplets, that is, fresh water, flows down along the inclination direction of the lighting body and is collected by the first water collecting section. Then, the fresh water collected by the first water intake means is taken.

On the other hand, a hydrophobic porous membrane is arranged on the bottom surface of the basin, and a cold seawater feeding means for feeding cold seawater is further provided below the hydrophobic porous membrane. Therefore, water vapor is generated and moves due to the temperature difference between the warm seawater and the cold seawater, and is condensed on the surface of the cold seawater feeding means and adheres as water drops. afterwards,
The fresh water collected by the second water intake means is taken.

That is, according to the present invention, not only the fresh water is taken in by the first seawater desalination means, but also the fresh water is taken in by the second seawater desalination means. Therefore, the efficiency of water production is improved.

According to the present invention of claim 3, claim 1
Alternatively, in the present invention according to claim 2, since the first seawater desalination means and the second seawater desalination means are unitized, almost no on-site construction work is required.

According to the invention of claim 4, claim 1
In the present invention according to any one of claims 3 to 3, since the warm seawater stored in the basin is circulated by the circulation pipeline, the residual heat of the warm seawater can be reused.
Therefore, the power consumption of the solar cell can be suppressed,
Contributes to energy saving.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a longitudinal sectional structure of a solar energy desalination apparatus 10 together with a control system, and FIG. 2 shows a sectional structure taken along line 2-2 thereof. .

As shown in these figures, the seawater desalination apparatus 10 includes a box-shaped base 12 having a hollow interior.
Is equipped with. A support 14 having an L-shaped cross section is fixed around the upper portion of the base 12. The support 14 is formed by, for example, assembling stainless steel so as to have an L-shaped cross section and filling the inside with a heat insulating material such as a foam material.

Since the above-mentioned support body 14 is arranged around the upper portion of the base 12, a storage upper portion 16 and a storage lower portion 18 are formed inside the support body 14. Upper part 1
6 is formed to be slightly larger than the housing lower portion 18 in a plan view, and a warm seawater inlet portion 20 is formed in the vicinity of its bottom portion so as to project. In addition, a warm seawater outlet 22 is formed at a predetermined portion on the housing lower portion 18 side so as to project. The accommodation upper part 16 and the accommodation lower part 18 function as a basin. It should be noted that the bottom surface of the basin is provided with a predetermined gradient in order to direct the water droplets of fresh water condensed on the surface of the cooling pipe 30 described later toward the fresh water outlet portion 41.

Further, a daylighting body 24 in the shape of a roof having a predetermined slope is fixed to the upper end surface of the housing upper portion 16, and the daylighting body 24 is adapted to illuminate sunlight. As the material of the daylighting body 24, acrylic, glass plate or the like is used. A pair of gutter-shaped supplementary water receivers 26 are provided near the end portion of the daylighting body 24 on the downstream side in the inclination direction (upper inner wall surfaces of the accommodation upper portion 16 facing each other). Each of the supplementary water receivers 26 is provided with a gradient so that when the fresh water is collected inside, the fresh water can flow down naturally. A nozzle-shaped fresh water outlet 28 is provided at the downstream end of the supplementary water receiver 26 in the inclination direction. The fresh water outlet portion 28 penetrates the wall surface of the support 14 and is exposed to the outside, and a hose or the like (not shown) is attached to the fresh water outlet portion 28 so as to conduct water to a water storage tank or the like installed at an appropriate location.

On the other hand, as shown in FIG. 3, a flat rectangular tubular cooling pipe 30 is arranged at the bottom of the housing lower portion 18. The cooling pipe 30 is inclined, and a cooling water inlet 32 is projectingly formed at an end portion on the downstream side in the inclination direction (that is, below the warm seawater outlet 22). In addition, a cooling water outlet 34 is formed in a protruding manner at the end of the cooling pipe 30 on the upstream side in the inclination direction (that is, below the warm seawater inlet 20). In this example, the inlet and the outlet of the warm seawater and the cooling water are reversed (countercurrent type), but there is no problem if the inlet and the outlet are in the same direction (cocurrent type).

A film frame 36 is mounted on the upper end surface of the cooling pipe 30 described above. As shown in FIGS. 3 and 4, the membrane frame 36 has a rectangular frame 38.
And a film 40 (illustrated by a broken line in FIG. 3) attached to the internal opening of the frame 38. As the film 40, a hydrophobic porous film is used. Therefore, this membrane 40 is impermeable to water but permeable to water vapor. Membrane frame 36 described above
Are fixed to the upper end surface of the cooling pipe 30 via a mesh-like separator 39 arranged in the opening portion (immediately below the film 40) of the frame 38. The separator 39 has a function of uniformly maintaining the distance between the surface (upper end surface) of the cooling pipe 30 and the film 40.

Further, a pipe-shaped fresh water outlet 41 is disposed downward near the end of the membrane frame 36 on the downstream side in the inclination direction. A hose or the like (not shown) is attached to the fresh water outlet portion 41 to introduce fresh water into a water storage tank installed at an appropriate location.

Next, the structure of the control system will be described. As shown in FIG. 1, the seawater intake part 42 is connected to the warm seawater inlet part 20 by a pipeline A. In the middle of this pipeline A, a three-way valve 46 driven by a motor 44 is arranged. A water intake pump 48 and a pretreatment filter 50 are arranged between the seawater intake part 42 and the three-way valve 46.

On the other hand, the warm seawater inlet 20 and the warm seawater outlet 2
2 is connected by a pipeline B. Thereby, the warm seawater inlet part 20 and the warm seawater outlet part 22 are closed loop, and constitute the circulation pipeline. A three-way valve 54 driven by a motor 52 is arranged at a connecting portion between the pipeline B which is the circulation pipeline and the pipeline A described above. This allows the pipeline to be changed as needed. Further, in the middle of the pipeline B, a circulation pump 56 is arranged, and a three-way valve 60 driven by a motor 58 is arranged.

Further, a level sensor 62 for detecting the water level in the basin is provided in the basin. The detection signal of the level sensor 62 is output to the control panel 66 connected to the solar cell 64. In the control panel 66, the intake pump 48, the circulation pump 56, and the motors 44, 5 described above are provided.
The drive of 2, 58 is controlled.

Next, the operation of this embodiment will be described. In the initial state before operation, the three-way valves 46, 54, 60 are set so that the solid arrow directions are the feed directions. In this state, a water intake signal is output from the control panel 66 to the water intake pump 48. As a result, the water intake pump 48 is driven and normal seawater is taken from the seawater intake part 42. Intake pump 48
When the seawater taken in by the water passes through the pretreatment filter 50, impurities (suspended organisms, algae, etc.) contained in the seawater are removed. After that, seawater is sent from the three-way valve 54 to the warm seawater inlet 20 via the pipeline A. The seawater introduced from the warm seawater inlet 20 (not warm seawater at this point) is stored in the storage lower part 18, and further in the storage upper part 16 (that is,
Water is stored in the basin). The level of seawater in the basin at this time is detected by the level sensor 62 and is constantly output to the control panel 66. In this way, when a certain amount of seawater is stored in the basin, the control panel 66 outputs a flow path switching signal to the three-way valve 46. As a result, the flow path of the three-way valve 46 is switched in the direction of the dashed arrow. As a result, the seawater pumped up by the water intake pump 48 is directly introduced into the cooling water inlet portion 32 of the cooling pipe 30.
The introduced cooling water (normal seawater) is discharged from the cooling water outlet portion 32 (or a desired portion when a hose or the like is attached to the cooling water outlet portion 32).

Even during the above-described steps, the daylight 24 illuminates the sunlight to heat the seawater stored in the basin. As a result, the seawater becomes warm seawater.
Then, at the time when the temperature reaches an appropriate temperature (it is preferable to provide a water temperature sensor to detect the appropriate temperature), the control panel 6
A flow path switching signal is output from 6 to the three-way valve 54. Therefore, the flow path of the three-way valve 54 is switched in the direction of the broken arrow. At this time, for the three-way valve 60, the direction of the solid arrow is as it is as the flow path direction. In this state, the control panel 66 outputs a circulation drive signal to the circulation pump 56.
Thereby, the warm seawater in the basin is circulated along the pipeline B which is a circulation pipeline.

Here, when the warm seawater in the basin reaches a predetermined temperature, steam is generated. This water vapor rises and is cooled on the back surface of the daylighting body 24. Therefore, the water vapor condenses into water droplets and flows down along the inclined surface of the daylighting body 24. The water droplets (that is, fresh water) that have flowed down are collected by the supplementary collecting water receiver 26, and then discharged from the fresh water outlet portion 28 and taken in.

On the other hand, the warm seawater in the basin and the cooling pipe 30
Due to the temperature difference with the cooling water inside, water vapor is generated in the film frame 36.
Permeate the film 40 of the above and move to the surface of the cooling pipe 30. Therefore, the water vapor is condensed on the surface of the cooling pipe 30 to form water droplets (that is, fresh water), which is discharged from the fresh water outlet portion 41 and taken in.

If evaporation continues in the above process, the amount of warm seawater in the basin will decrease, and the salt concentration of the warm seawater will increase. Therefore, when the level sensor 62 detects the water level and reaches a predetermined water level (for example, the water level in the basin is 1/3 of the initial level).
If so, the salt concentration will be three times the initial concentration, so at this point) a flow path switching signal is output from the control panel 66 to the three-way valve 60, and concentrated seawater is discharged from the warm seawater outlet 22. The discharged concentrated seawater is sent to a salt-forming device (not shown) or the like and separated into fresh water and salt. Next, the level sensor 62 sends a signal of water level 0 to the control panel 66, a flow path switching signal is output from the control panel 66 to the three-way valve 46, and seawater is again taken from the seawater intake part 42 and replenished in the basin. It

As described above, in this embodiment, not only the fresh seawater is obtained by evaporating a part of the warm seawater by the light collector 24 using the basin type but also the pervaporation (PV).
Since fresh water can be obtained by utilizing the temperature difference between the warm seawater and the cooling water using the membrane, the efficiency of water production can be doubled.

Moreover, according to the present embodiment, the seawater desalination apparatus 10 itself is compact and unitized.
On-site construction work is almost unnecessary. In this respect, since the conventional structure has low water production efficiency, it is necessary to install a seawater desalination device in a wide area to compensate for this, and a large amount of on-site construction work is required for foundation construction, etc. According to the example, since the efficiency of water production is unitized, the on-site construction work will be extremely reduced.

Further, according to the present embodiment, the mechanical construction eliminates the need for maintenance personnel such as high-voltage management. Therefore, the maintainability is excellent. Therefore, it is particularly effective in areas where lifeline facilities are insufficient.

Further, according to this embodiment, since the warm seawater in the basin is circulated by the pipeline B which is a circulation pipeline, the residual heat of the warm seawater can be reused. Therefore, the power consumption of the solar cell can be suppressed and energy saving can be achieved.

Further, according to the present embodiment, since the net-like separator 39 is arranged immediately below the membrane 40, it is possible to prevent the membrane 40 from being slackened due to the weight of warm seawater. It is possible to make the gap between the cooling pipe 30 and the upper end surface of the cooling pipe 30 uniform.

In this embodiment, the daylight 24 collects sunlight to turn the seawater in the basin into warm seawater. However, in order to improve the efficiency, the side surface of the upper housing 16 and the lower housing 18 are accommodated.
The side surfaces and the bottom surface, the surface of the frame 38 of the membrane frame 36, and the like may be blackened.

[0043]

As described above, the seawater desalination apparatus according to the present invention has an excellent effect that the efficiency of water production can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a longitudinal sectional structure of a seawater desalination apparatus according to a present embodiment together with a control system.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

3 is a sectional view taken along line 3-3 of FIG.

FIG. 4 is a plan view of a membrane frame.

FIG. 5 is an overall configuration diagram showing an overall configuration of a seawater desalination apparatus according to a conventional structure.

[Explanation of symbols]

10 Seawater Desalination Device 16 Upper part of storage (basin, first seawater desalination means) 18 Upper part of storage (basin, first seawater desalination means) 24 Daylighting body (first seawater desalination means) 26 Supplementary water receiving (first) Water collection part, first seawater desalination means 28 Desalination outlet part (first water intake means, first seawater desalination means) 30 Cooling pipe (cold seawater supply means, second water collection part, second seawater desalination means) ) 40 membrane (hydrophobic porous membrane, second seawater desalination means) 41 freshwater outlet (second water intake means, second seawater desalination means)

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-52-92873 (JP, A) Actually open 54-105046 (JP, U) Actually open Sho-56-34597 (JP, U) Actual public 50- 190 (JP, Y1) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C02F 1/02-1/14

Claims (4)

(57) [Claims] 1. A first seawater desalination process in which seawater stored in a basin is converted to warm seawater by using the sunlight obtained as a heat source to generate warm water vapor, and water vapor generated by condensing the generated water vapor is collected. Means and a hydrophobic porous membrane on the bottom surface of the basin, and further provided below it with cold seawater feeding means for feeding cold seawater. Due to the temperature difference between the hot seawater and the cold seawater, the cold seawater feeding means A seawater desalination apparatus comprising: a second seawater desalination unit that collects and collects water droplets condensed on the surface. 2. A daylighting body arranged in a tilted state to illuminate sunlight, a basin arranged below the daylighting body to store warm seawater heated by the sunlight, and to generate steam. The first to collect water droplets generated by the water vapor generated in the basin condensing on the surface of the lighting body
A first seawater desalination unit including a water collection unit and a first water intake unit that takes in the fresh water collected in the first water collection unit, and a hydrophobic porous structure arranged on the bottom surface of the basin. A membrane, a cold seawater feeding means arranged below the hydrophobic porous membrane to feed cold seawater, and a second water collecting portion for collecting water droplets condensed on the surface of the cold seawater feeding means, A seawater desalination apparatus comprising: a second seawater desalination unit configured to include a second water intake unit that collects the fresh water collected in the second water collection unit. 3. The seawater desalination apparatus according to claim 1, wherein the first seawater desalination means and the second seawater desalination means are unitized. 4. The seawater desalination apparatus according to claim 1, wherein warm seawater stored in the basin is circulated by a circulation pipeline.