ES2393507B1 - SEA WATER DESALINATION UNIT. - Google Patents

Abstract

Seawater desalination unit. # It has racks provided with reverse osmosis membranes (1) connected to saltwater and desalinated water collector circuits (2) inside a submersible chamber (3) attached to a base-counterweight (5) with hooking means (6) for immersion and lifting; said chamber (3) being connected to: an outlet pipe to the outside of desalinated water (7) in which a first tank-pump (9) is inserted; an outlet pipe to the outside of brine (8) in which a second tank-pump (10) is inserted; and at least one salt water inlet with a suspended particulate filter (4, 11, 12, 13); said chamber (3) being located at a first value of marine depth of at least 700 m with a tolerance of 10%.

Description

SEA WATER DESALINATION UNIT

OBJECT OF THE INVENTION

The present invention, as expressed in the

statement of this specification, consists of a

5

seawater desalination unit whose essential purpose

is to provide an alternative to desalination plants

terrestrial, taking advantage of the pressure generated in the

seabed to separate water from solutes instead of

resort to the application of electrical energy or

10

artificial generation of pressure differences in

earth, for which the invention provides a structure

with racks provided with reverse osmosis membranes in

the interior of a chamber that is submerged to depths of

approximately 700 m, in order to start the process of

fifteen

separation of water and solutes with a yield

energy comparable or higher than that of the units

state-of-the-art desalination plants.

BACKGROUND OF THE INVENTION

We know various records regarding systems

twenty

to desalinate sea water such as the Spanish patent with

publication number 2.112.206 and listed as "system

with fixed or mobile support for desalination of

sea with reverse osmosis cell device,

submerged at variable working depthsquot ;; As the

25

Spanish utility model with publication number

1,070,065, stated as "unit of desalination and pumping of

marinaquot ;; such as French patent n ° 2,484,391

listed as "water production process and device

sweet from marquot water ;; or like the patent

3 O

American No. 3. O60. 119 stated as quot; conversion of

salt water in drinking waterquot ;.

As these records reflect, the

technique of desalinating seawater using endowed structures

of reverse osmosis membranes, using high

35

deep seawater pressures to facilitate

corresponding osmotic exchange in these membranes, which, subjected to the different internal and external pressures of an enclosure enclosed by them, allow pure water to pass in one direction but not the salts in solution that may exist.

This use of the pressure existing in the deep sea has energy advantages with respect to the production of the necessary pressures on land, since this requires artificially making the aforementioned pressure difference.

Among the aforementioned records, we consider patent 2,112,206 and utility model 1.070065 to be closer to the present invention. In the first case, as stated in its summary, it is a system for desalination of seawater using a device consisting of one or more modules with high resistance to pressure and corrosion, which, having the appropriate number of reverse osmosis cells go submerged at great working depths. All this supported either by ship, platform or any other fixed or propelled system, this last element being able to act both as a physical support for the pressure modules and for the different desalination water transfer systems obtained in depth up to the surface; of central

storage,

distribution and supply, being able

represent

a alternative to the plants conventional,

even

in performance economic.

As can be seen in the figures of the aforementioned patent, the practical embodiment of this system is a kind of spherical capsule where the osmotic exchange is carried out and which is connected to a ship by means of cables and pipes. Although the system of this patent with publication number 2,112,206 uses the same technology as the present invention, it is a very different structure from that of the present invention; Furthermore, the protective scope defined by the characterizing part of the first claim of that patent is excessively generic, so that it does not contribute any novelty to the state of the art that was known before 1996, the year of application for this patent 2,112,206, according to it can be demonstrated with the aforementioned US patent document 3,060,119.

On the other hand, regarding the utility model

1.070.065 it is worth mentioning that the characterizing part of its first claim indicates that it "comprises one or more deep-submersible reverse osmosis units consisting of steel tubes with semi-permeable membranes inside and anchored to the seabed so that it can occur the desalination by the own marine pressure, which have pre-filters, tubes for the elimination of brine, lead weights, anchors for fixing to the seabed, and steel cables connected to a platform

or floating buoy for control and maintenance, the aforementioned reverse osmosis units being connected directly by tubes to one or more submersible tanks to which the desalinated water passes and these are connected by tubes to a water pump that pumps the water from the tanks to maintain the pressure difference between the tanks and the osmosis units.

Although some of the elements of the present invention, such as pumping devices, tanks and filters, are in this utility model, the structure and functionality of these elements, even without being detailed in the corresponding document, it is seen that it is notably different from that of the present invention, requiring in the two embodiments shown in said document a system for taking advantage of the non-existent force of gravity in the system of the invention, referenced as 1 in this utility model. Furthermore, the tanks 3 that this utility model uses are well submerged at the level of the reverse osmosis units 2, according to the embodiment shown in figure 1, or floating at sea level, as shown in figure 2 of the second embodiment in said utility model, and not in particularly suitable intermediate depths as can be seen in the structure of the present invention. Furthermore, this state-of-the-art utility model also has the drawback pointed out for the patent of not providing novel technical characteristics that facilitate an efficient and viable system in desalination of sea water through pressure changes due to deep immersions.

DESCRIPTION OF THE INVENTION

To achieve the objectives and avoid the drawbacks indicated in previous sections, the invention consists of a seawater desalination unit that has racks provided with reverse osmosis membranes that use the high pressure of deep seawater to facilitate the corresponding osmotic exchange. in the referred membranes.

Novelty, according to the invention, said frames are connected to saltwater and desalinated water connector circuits inside a submersible chamber attached to a base-counterweight with hooking means for immersion and hoisting; connecting said camera

a: an outlet pipe to the outside of desalinated water in

the

than I know sandwiched a first tank-pump; a

driving

of departure to the Exterior of brine in the than I know

sandwiched

a second tank-pump; and to the less a

inlet water with suspended particle filter; the aforementioned camera being located at a first value of marine depth of at least 7 O O m with a tolerance margin of 10% of said first value.

According to a preferred embodiment of the invention, said hooking means consist of rings that can be connected to lifting and dipping chains. Furthermore, in said preferred embodiment of the invention, the first tank-pump is located at a second depth value of 350 m less than the referred first value of the submerged chamber, and also with a 10% tolerance for this second value; while the aforementioned second tank pump is located at a third depth value of 450 m less than that of the first value of the mentioned chamber, as well as in the previous cases with a tolerance of 10% for this third value.

On the other hand, in the aforementioned preferred embodiment of the invention, the aforementioned filtered salt water inlet is selected from:

-

one or more openings with respective filters in the body of the camera;

-

the aforementioned one or more openings with filters in the body of the chamber plus an additional opening of the chamber that is connected to a saltwater line ending in an additional filter of suspended particles for the entry of saltwater.

Another characteristic of the preferred embodiment of the invention consists in that said additional filter of particles from the saltwater line is located at a fourth depth value that is 60 ± 10% m from the sea surface.

Furthermore, this additional particle filter of the preferred embodiment of the invention is installed in an arrangement selected from: free immersion at said fourth depth value, and connected by a cable

or connection link to a marine platform, boat, cliff, coast or other surface station.

On the other hand, according to various embodiments of the invention, some, several or all of said pipes are capable of incorporating buoyancy elements that prevent their sinking.

In addition, in the seawater desalination unit of the example of the invention the location thereof is selected from:

-location parallel to a cliff, so that the brine line is arranged vertically and after leaving

from said second tank-pump empties freely into the atmosphere on the sea surface; while the desalinated water pipeline, also arranged vertically, after leaving the aforementioned first reservoir-pump empties into the land surface of the cliff by means of a bend for its use or redirection to the distribution or supply network after mineralization;

location in proximity to the sea coast, so that the brine line is arranged vertically and after leaving the said second tank-pump it empties freely into the atmosphere on the sea surface; while the desalinated water line after leaving the

referred

first tank-pump I know carries to the coast on the

background

Marine with the inclination natural than beats the

correspondent

unevenness for its exploitation or

redirection

to net of distribution or supply after its

mineralization;

Location

low platform Marine or boat, of

so that the brine line is arranged vertically and after leaving said second tank-pump it empties freely onto said platform or vessel; while the desalinated water pipeline, also arranged vertically, after leaving the said first tank-pump empties onto the platform or vessel for use or storage.

With the structure that has been described, the invention presents advantages relative to the use of the force of gravity and the pressure of the deep sea as energies that allow the reverse osmosis process to develop without the need to create artificial structures that generate the corresponding pressure. Another advantage of the invention is that it provides mobile units without the need for large-volume land structures, so its environmental and urban impact is very low.

or null. Furthermore, the desalination unit of the invention does not cause deterioration or destruction of the

zones or ecosystems where it is included, leaving that zone or ecosystem with the same environmental characteristics as those that existed prior to the installation of the unit. The invention has advantages in that the operating costs are relatively small since large structures are not required for its development. By means of the invention, drawbacks of the state of the art are overcome by providing a structure that optimizes energy efficiency, facilitating the most convenient conduits and depth values for a depth desalination unit in marine waters.

Below, to facilitate a better understanding of this specification and forming an integral part thereof, some figures are attached in which the object of the invention has been represented by way of illustration and not limitation.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1.- Represents a schematic elevation view of a seawater desalination unit made according to the present invention.

Figure 2.- Represents a schematic profile view of the seawater desalination unit of figure 1 above.

Figure 3.- Represents a schematic top plan view of the desalination unit of the previous figures.

Figure 4.- Is a schematic view of the desalination unit of the previous figures 1 to 3 in a first application in which it is arranged with a location parallel to a cliff.

Figure 5.- Is a schematic view of the desalination unit of the previous figures 1 to 3 in a second application in which it is arranged in a location near the sea coast.

Figure 6.- Represents a schematic view of the desalination unit of the previous figures 1 to 3 for a third application in which it is arranged with a location under a marine platform or vessel.

DESCRIPTION OF AN EXAMPLE OF EMBODIMENT OF THE INVENTION

Next, a description of an example of the invention is made with reference to the numbering adopted in the figures.

Firstly, we provide a list of the numerical references of the six figures in this document indicating their meaning:

1: Racks with reverse osmosis membranes.

2: Desalination and brine water collector circuits.

3: Camera or rack enclosure l.

4: Filter openings in chamber 3.

5: Camera base-counterweight 3.

6: Chain hook eyes 19.

7: Conduction of desalinated water.

8: Brine conduction.

9: First tank-pump for extraction of desalinated water.

10: Second tank-brine extraction pump.

11: Additional opening for seawater inlet into chamber 3.

12: Sea water line connected to additional opening 11.

13: Additional filter for inlet water in line 12.

14: Marine surface.

15: Cliff.

16: Marine coast.

17: Boat.

1 8: Additional filter holding cable 13 on boat 17.

19: Lifting and immersion chains of the base-counterweight

5 .

As can be seen in Figures 1, 2 and 3, where the elevation, profile and plan views of the desalination unit of the present example are shown schematically, the frames with reverse osmosis membranes 1 are connected to water collecting circuits salty and desalinated water 2 inside a submersible chamber 3.

Said frames 1, as well as circuits 2, are made with materials that have high resistance to pressure and corrosion, such as stainless steel. In chamber 3, the pressure is equalized by the entry of water through the filter openings 4, so that a large structural reinforcement is not necessary in said chamber 3.

Chamber 3 is jointly attached to a base-counterweight 5 that can be made with reinforced concrete and that includes hooking means consisting of rings or eyelets 6 that facilitate hooking chains 19 to facilitate immersion and hoisting of the unit , as can be seen in figure 6.

Furthermore, chamber 3 is connected to an outlet pipe to the outside of desalinated water 7 in which a first tank-pump 9 is inserted, to an outlet pipe to the outside of brine 8 in which a second tank-pump is inserted. 10, and several salt water inlets provided with a suspended particulate filter.

Said various inlets with filtered salt water consist, in the present example, of openings with filter 4 made in the body of the chamber 3 and in an additional opening 11 which is prolonged in a line of sea water 12 by the exterior of the chamber. 3 until ending in an additional filter 13, as can be seen in figure l.

This additional filter 13 may or may not, depending on various applications, be connected via a connecting cable or link

18 to a surface station or vessel 17, as can be seen in figure 6.

With the structure that has been explained, the technique for using the desalination unit of the present example consists in introducing chamber 3 with its associated elements at a depth of about 7 OO m so that the sea water that reaches the frames 1, free of coarse particles in suspension, by virtue of the additional filter 13 and the filters of the openings 4, reach the frames 1, so that once the osmotic exchange has taken place, the desalinated water rises through line 7 approximately 350 m from the location of the camera 3 to 7 OO m deep, so that it would take approximately a distance of another 350 m to bring it to the surface. At the same time, the brine ascends through line 8 about 450 m with respect to the location of chamber 3 at a depth of 700 m, so that there would be approximately 250 m left to take it to the sea surface 14. In order to complete the natural rises The first and second pump tanks 9 and 10 are used for brine and desalinated water at the appropriate depths, as can be seen in the

figure

Four. So, the first tank-pump 9 I know has

approximately

350 m low the surface Marine 14, in

so much

than the second tank-pump 10 I know has

approximately

to 250 m of depth respect of the

marine surface 14, all of which being camera 3 at a depth of about 700 m with respect to said marine surface 14, as shown in figure 4.

On the other hand, the additional filter 13, with the depth values previously referred to for pump tanks 9 and 1 O and for chamber 3, is located at a depth of approximately 60 m below the surface of the sea 14.

To calculate the internal diameters of pipes 7 and 8, as well as the capacities of the

tanks 9 and 10 and the strength of their respective pumps,

make estimates of the desired water flows

extract with the desalination unit from the specific application.

To insert the hollow pipes of the unit

5

desalination plant at the mentioned depths, we must calculate

the weight of the liquid they are going to dislodge and counteract it

with a mass that develops the opposite thrust

at this force, which calculates the mass that must

display base-counterweight 5 with camera 3. In addition, the

10

The unit should be introduced into the water at a

speed controlled so that structures are not damaged

corresponding functional, which is done through

of the anchors provided by the rings 6 connected to

chains 19, which will serve both immersion and

fifteen

for lifting the desalination unit.

The openings presented by camera 3 in the present

example are three or four depending on the needs of

the input of salt water that has been calculated, being

see in Figures 1 and 2 three openings with filter 4

2 O

plus additional opening 11 with additional filter 13,

that were mentioned earlier. In the body of the

camera 3 there should always be some opening to allow

the entry of salt water from the beginning of the process

immersion of chamber 3 and thus allow its filling

25

facilitating the process.

Filters of openings 4 and the additional filter

13 free water to desalinate from coarse particles such

such as sand, aquatic flora and fauna or others, so that

salty water passes into chamber 3 clean of

30

impurities putting pressure on the membranes

semipermeable racks 1, and upon reaching the

necessary depth the separation process begins in

desalinated and brine water through the osmosis process

reverse, bringing desalinated water from each rack 1

35

passes to a part of circuits 2 corresponding to water

desalinated until reaching line 7 at the height of

first pump reservoir 9, being artificially pumped from there to the surface. For its part, the brine resulting from the aforementioned process is collected in another part of the circuits 2 to flow into the line 8, rising to the level of the second tank-pump 10, pumping from there to the surface.

Figure 4 represents the comments for the application with a location parallel to a cliff 15, which turns out to be the ideal case of application of the unit of the present example, since the desalinated water outlet can be directly connected to a supply network after the necessary mineralization process of the same, so that in

this

application of the figure 4 the expenditure energetic and in

materials

result minimum respect of others two

Applications

than I know they explain below.

Another application consists in arranging the unit in a location in proximity to the marine coast 16, which results in everything analogous to the previous application, with the exception that the desalinated water pipe 7 is carried with the inclination corresponding to the natural level instead vertically, adding in this case some structures such as floats that prevent the sinking of the pipes, resulting in this higher application the expenditure on materials and energy for the extraction of desalinated water.

Another application is shown in figure 6, in this case with the unit arranged in a location under a marine platform or boat 17, as shown in figure 6. In this case, the unit is located on the deck of the boat 17, and by means of a crane and motors system, the corresponding immersion is carried out, with which the unit is installed vertically on the ship or vessel 17, which will serve as an installation platform, desalinated water tank and transport from it to a distribution network or mother ship for filling other transport vessels.

The expenses in this application are small since the desalination unit is located in the vertical position of the vessel 17, the energy expenditure being somewhat greater than that of the unit parallel to the cliff 5, but with the advantage in this application of the vessel 17 , that the investment in structures is not subject to a physical space, being able to provide service at different points; giving in addition the additional advantage that the brine resulting from the process is not poured regularly in the same point or zone, being therefore less damage to the natural conditions of the environment where it is poured. On the other hand, the necessary change of racks and the mobile nature of the installation allow periodic reviews that facilitate the

maintenance.

Others

Applications and examples of the invention are

equally

possible, how by example in a platform

fixed,

even if in this case the costs structural and the

Environmental and ecological characteristics make this application less attractive.

It has been estimated that without amortization of materials, with pumps of 25,000 1 / h and using a mid-range generator on the market, the cost per liter of desalinated water, using the desalination unit of this example in the application that uses vessel 17, it is around € 0.18, less than 30% of the cost per liter of an efficient conventional on-site desalination plant that is around € 0.31 per liter. The total investment has an estimated margin of € 30,000,000 using a small boat 50m long, 10m wide and 4m draft with full tanks; having calculated that for a consumption of 150 1 per person per day, a population of 8,000 people could be supplied with water. With a 100 m long ship it could supply about 30,000 people, and with a 150 m long ship it could supply about 90,000 people.

Claims (4)

  l.-SEA WATER DESALINATION UNIT, which has racks provided with reverse osmosis membranes (1) using the high pressure of marine waters 5 deep to facilitate the corresponding osmotic exchange in the referred membranes; characterized in that said frames (1) are connected to saltwater and desalinated water collector circuits (2) inside a submersible chamber (3) attached to a base 10 counterweight (5) with hooking means (6) for immersion and hoisting; said chamber (3) being connected to: an outlet pipe to the outside of desalinated water (7) in which a first tank-pump (9) is inserted; an outlet pipe to the outside of brine (8) in which it is inserted 15 a second tank-pump (10); and at least one salt water inlet with a suspended particulate filter (4, 11, 12, 13); the referred chamber (3) being located at a first value of marine depth of at least 700 m in conditions of typical marine salinity and with a margin of 20 tolerance of 10% of said first value. 2.-SEA WATER DESALINATION UNIT, according to claim 1, characterized in that said hooking means consist of rings (6) connectable to lifting and immersion chains (19). 25 3.-SEA WATER DESALINATION UNIT, according to claim 1 or 2, characterized in that the first tank-pump (9) is located at a second depth value of 350 m less than the referred first value, also with 10% of tolerance for this second value; and 30 the aforementioned second tank-pump (10) is located at a third depth value of 450 m less than that of the aforementioned first value, and also with a tolerance of 10% for this third value. 4.-SEA WATER DESALINATION UNIT, according to any one of the preceding claims,

characterized in that said salt water inlet with

Filters is selected from:

-one or more openings with respective filters (4)

in the body of the camera (3),

5

-the referred one or more openings with filters (4)

on the camera body (3) plus an additional opening

(11) of the camera (3) that is connected to a pipe

salt water (12) ending in an additional filter (13)

of particles in suspension for entry of salt water.

1 O

5.MARINE WATER DESALINATION UNIT, according to

Claim 4, characterized in that said filter

additional particles (13) from the water line

salty (12) is located at a fourth depth value that

it is 60 ± 10% m from the sea surface (14)

fifteen

6.MARINE WATER DESALINATION UNIT, according to

Claim 4 or 5, characterized in that that filter

additional particles (13) from the water line

salty (12) is installed in a selected arrangement

between: free immersion to the referred fourth value of

twenty

depth, and connected by a connecting cable or link

(18) to a marine platform, boat (17), cliff

(15), coast (16), or other surface station.

7.MARINE WATER DESALINATION UNIT, according to a

any one of the preceding claims,

25

characterized by some, several or all of the referred

pipes (7, 8, 12), according to applications and installation

desalination unit, incorporate elements of

buoyancy that prevent its sinking.

8.MARINE WATER DESALINATION UNIT, according to a

30

any one of the preceding claims,

characterized in that the location of the desalination unit

is selected from:

-location parallel to a cliff (15), so

that the brine line (8) is arranged vertically, and

35

after leaving said second tank-pump (1 O)

freely empties into the atmosphere on the sea surface (14); while desalinated water conduction (7), also arranged vertically, after leaving the aforementioned first tank-pump (9) empties into the land surface of the cliff (15) by means of a kink for its use or redirection to the distribution or supply network after its mineralization; location near the marine coast (16), so that the brine line (8) is arranged vertically, and after leaving the said second tank-pump

(10)

freely empties into the atmosphere on the sea surface (14); while the desalinated water pipe (7) after leaving the first tank-pump

(

9) it is brought to the coast (16) on the seabed with the natural inclination that exceeds the corresponding unevenness for its use or redirection to the distribution or supply network after its mineralization;

location under the marine platform or vessel (17), so that the brine line (8) is arranged vertically and after leaving the said second tank-pump (10) it empties freely onto said platform or vessel (17); while the desalinated water pipe (7), also arranged vertically, after

go out

of the referred first tank-pump (9) empties

on

the platform or boat (17) for its

exploitation

or storage.