FR2843383A1 - Sea water desalination tower is constructed on piles in the sea near the shore on a base about 10 m above maximum sea level - Google Patents

Abstract

The desalination tower is constructed in the sea close to the shore where the water is 10 - 20 m deep. It has a cylindrical base (1) supported by piles (10) set on a reinforced ring (11) which can also have piles (12), depending on the nature of the sea bed, with the base set about 10 m above maximum seal level. The base of the tower tapers upwards towards a neck (2), and then diverges towards its summit (3). The neck has an internal diameter of about 100 m for a tower 300 m tall, and is situated at a height of about 140 m. The summit has an internal diameter of about 130 m and has an annular platform (4) some 15 m wide on which wind-driven turbines of about 1.5 MW each are installed. A second platform (5) is located just above the neck, and the two platforms are supported by ribs (6, 7). Inside the tower there is a condenser above neck level. A breaker wall with apertures to let water pass through can be constructed on piles round the tower at a distance equivalent to at least the radius of its base to give protection against storms.

Description

Mass desalination tower of seawater disposed at sea on the edge of

side.

  The invention relates to a seawater mass desalination tower, disposed at sea, operating by evaporation of seawater inside a tower provided with

  condensers and means for recovering condensed water.

  There is already known a seawater desalination tower built on land at the edge of the coast, provided with walls allowing the rotation of the air so as to create a self-maintained artificial cyclone inside the tower . The condensers form a serpentine with several turns fixed against the internal wall of the tower. The water is brought into a basin, under the tower, by a channel provided with a level control lock. The brine is collected in a saline built near the evaporation basin. The overflow of brine is rejected

to the sea by pumping.

  This tower has the disadvantage of producing a very large quantity of salt which will be very difficult to flow and will require spending a lot of energy to reject the brine to

the sea.

  To overcome this drawback, the desalination tower according to the invention is built on stilts on the sea at the edge of the coast, on sites whose depth is between 10 and 20 meters at most. To protect the site in the event of a storm, the tower is partially or completely surrounded by a breakwater wall, allowing water to pass through multiple openings, also built on stilts. Unlike the evaporation basin of a tower 20 built on land, the sea surface is never flat, but constantly agitated by the wind. Its surface of exchange with the wind is therefore much larger than the flat surface of a basin. We can consider that on average this evaporation surface near the tower and under it, is at least doubled which increases the amount of water collected to around

3 million m3 / 24 hours.

  This tower works like a chimney and not like the tower mentioned above, it is built at sea on stilts along the coast on sites at a depth between 10 and 20 meters, it has a cylindrical base resting on stilts themselves arranged in abutment on an annular raft which may, depending on the nature of the soil, itself be in abutment on posts, said base being situated approximately 1 Om above the maximum sea level; 30 said tower is broadly flared at its base, it rises gradually tapering to the neck and then widens towards its top, the neck, with an internal diameter of about 100 m for a tower 300 m in height, is about 140 m high and the top with an inside diameter of about 130 m, the top has an annular platform with a width of about 15 mni on which are installed wind turbines '' about 35 1.5 MW each; a second platform is placed slightly above the neck,

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  these two platforms are supported by ribs; a condenser assembly is arranged

  above the pass inside the tower.

  To protect the site in the event of a storm, the tower is partially or completely surrounded, at a distance at least equal to the radius of the base of the tower, by a breakwater wall allowing water to pass through multiple openings , said wall also being built on stilts. The tower is assembled in rows of prefabricated modules at the factory, for example by means of three cranes, of the tower or jib type, placed on a horizontal row of modules and raised every 30 meters; the tower is built by installing and assembling modules. comprising tenons and mortises for their vertical and horizontal assembly. 10 Several modules that can be fixed side by side by means of pre-tensioned tie rod; each new row of modules being different from the previous one, some modules have

  inserts for fixing external or internal elements to the tower.

  An access bridge is built on stilts from the coast to the tower. It is anchored on the base of this, the freshwater evacuation pipes being fixed under this bridge to reach the coast, as well as the cables for transporting the electrical energy produced by the wind turbines

  arranged on the upper platform of the tower.

  Guillotine doors regulate the air inlet or block this inlet. They are arranged between the foundation piles of the tower; they are each engaged in a corresponding slide of each of the foundation piles. The operation of these doors is ensured in synchronism by a chain or cable and pulley system cooperating with means for raising and lowering assisted by counterweights for balancing the mass of the doors; they are each mounted on a bracket attached to the top of the periphery of the

  wall of the tower to the right of the stilts.

  A condenser assembly is arranged inside the tower and above the neck in radiating rows of supports of condenser modules mounted in staggered rows, offset from one another so as to provide together a maximum of surface exchange

with ascending air.

  The exchanger modules are mounted in rows, each placed on their support and connected

  by flexible hoses and quick couplings with non-return valve, to the common 30 refrigerant pipes.

  For their installation, the exchanger modules are moved on swings from the elevators by levels, to the different rows of each level, these swings moving by means of a wheel rolling on a fixed rail with possibly a counter rail, the wheel being mounted freely rotating on an axis integral with the upper end of a bent tube 35,

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  This tube forms the body of the swing and has at its base means for installing and holding the condenser module; the rails and counter rail are arranged parallel to each row; rails and counter rails are arranged near the inner wall of the tower and parallel to it so as to be able to distribute the modules between the different rows from the elevators. Access to the condenser modules is provided by three elevators arranged 120 from one another, provided to be able to stop at each of these levels and each comprising a large external landing so as to be able to unload the modules at each level. Each row of modules of each level is equipped with an access walkway connected to an annular walkway (fixed to the internal wall of the tower) which makes the connection between the rows of the same level, fixed to each other at their free end by connecting arms and fixed

  between levels by a mesh connected to the wall of the tower.

  Each radiating row of modules is placed above a collecting chute collecting fresh water flowing over the condenser modules of its row, each chute 15 of a level being connected to an annular collecting pipe, itself connected to the pipes

  descent of fresh water from the drainage system to distribution to users.

  The overall operation of the tower is controlled by a set of sensors including: control of the air speed at the entrance and at the exit of the tower; air humidity control at the entrance and exit of the tower; control of the temperature of the air entering and leaving the tower and in several zones of the condenser assembly; control of temperature variations on the condenser assembly, between the parts of the tower exposed to the sun and the parts in the shade and control of the induced voltages; temperature control

  Seawater; freshwater flow control by level and global control for all levels; seismographic control; control of electrical energy production by the 25 wind turbines and of electrical consumption by the condenser assembly.

  The top of the tower has an annular platform with a width of about 15 m

  on which is installed a set of wind turbines of around 1.5 MW.

  The invention will be better understood on reading the following text with reference to the appended drawings given by way of nonlimiting examples, in which: + Figure 1 shows, in section in elevation, an example of the tower according to the invention ; * Figure 2 shows the arrangement of the piles at the base of the tower in top view, * Figure 3 shows, in top view, the tower and its environment; + Figures 4 and 5 show in partial view, in elevation and in section, an example of a breakwater wall;

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  + Figures 6, 7 and 8 show an example of guillotine doors to shut off or regulate the air supply at the base of the tower and their maneuvering means; + Figure 9 shows an example of the tower construction method; * Figure 10 shows an example of factory prefabricated elements used for the construction of the tower; + Figure 11 shows, in top view, the arrangement of the condenser module supports mounted by levels; + Figure 12 schematically shows an example of mounting the condenser modules on their support and their connection to the refrigerant flow pipes; 10 * FIG. 13 shows an example of a swing for operating the modules of

  condenser for their installation or their extraction.

  As shown in section in Figure 1, the tower is broadly flared at its base 1, it rises gradually narrowing to the neck 2 then flares towards its top 3. For a tower 300 m high the base is 300m in diameter, the neck 15 with an inside diameter of about 100m to about 140m in height and the top is an inside diameter of about 130m. The summit 3 comprises, on the outside, an annular platform 4 with a width of approximately 15 m on which are installed fifteen wind turbines of approximately 1.5 MW each. A second platform 5 is arranged slightly

  above the neck 2. These two platforms, confer an annular rigidity to the tower; they 20 are supported by ribs 6 and 7.

  The height 8 of the base of the tower above the maximum sea level 9 is approximately ni. This opening height of 1Om is maintained regardless of the amplitude of the tides

  by means of regulation doors located at the base of the tower.

  The base of the tower is mounted on piles 10 supported on an annular raft 11, itself 25 possibly supported on piles 12 depending on the nature of the soil. Surveys are done

  beforehand to check the resistance of the soil.

  Figure 2 shows the arrangement of the piles 20 at the base of the tower in top view.

  These piles support the weight of the tower, their number and their section are a function of the weight of

  the tower and the efforts they have to bear according to its shape.

  Figure 3 shows, in top view, the tower and its environment. The tower 25 is partially or totally surrounded by a breakwater wall 26. Here the wall partially surrounds the tower, beyond the axis XX ′ the wall 27 extends perpendicular to this axis or

  slightly sloping outwards or inwards; a footbridge or better, a bridge 30 connects the tower to the coast. An annular walkway 31 connects the end of the bridge to the elevators 35 32, 33, 34.

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  Figures 4 and 5 show in partial view in elevation and in section, an example of a breakwater wall 26. The height of this wall is a function of the amplitude of the greatest tides and the highest storm waves. It descends below the level of the highest tide

  low. At least two rows of oval shaped holes 35 pass through this wall, allowing water to pass, but breaking the waves. These holes are more widely spaced in part 27 of the wall. The wall 26, 27 is mounted on piles 36 secured to support pads 37.

  Figures 6, 7 and 8 show an example of guillotine doors arranged at the periphery of the base of the tower and their maneuvering means. These doors 40 have the function of closing off the spaces between the posts 41, 42 of the tower foundation. They allow to intervene inside the tower without being bothered by the wind and also to regulate the air intake Figures 6 and 7 show a cross section of one of the doors 40 and an elevation view of two ends of neighboring doors each engaged in a corresponding slide G1, G2 (fig.8) of each of the pillars of the tower foundation. The operation of the doors 40 is ensured in synchronism by a chain or cable system 45 and pulleys 46 and by hydraulic or electromechanical means of raising and lowering 47, assisted by counterweights 48 for balancing the mass of the doors, the hydraulic maneuvering systems being each mounted on a bracket 49 secured to the top of the periphery of the

  wall of the tower to the right of the stilts.

  The maximum downhill travel of the gates is planned according to the maximum amplitude of the tides. The doors are lowered to a level such that at the lowest tide their lower part is engaged in the water so as to completely block the air supply to leaks near the level of the slides. During normal operation, the doors are fully or partially raised depending on whether or not air inlet regulation is introduced. Figure 9 shows, schematically in partial perspective view, an example of construction of the tower. It is assembled in rows R of modules M prefabricated in the factory, for example by means of three cranes, of the tower or jib type, placed on a row and raised every 30 meters. The construction of the tower is carried out by laying and assembling

  modules. containing tenons and mortises for their vertical and horizontal assembly.

  When the rigidity of the tower justifies it, several modules are assembled side by side. By means of prestressed tie rods, FIG. 10 shows an example of elements prefabricated in the factory or modules M used for the construction of the tower. These modules include mortises 55 and tenons 56

  for their vertical assembly and tenons 57 and mortises 58 for their horizontal assembly 35 by tie rods 59. Each new row of modules is different from the previous ones.

  The different row modules are identified and some have inserts for fixing external or internal elements to the tower (fixing of elevators, freshwater downpipes, internal and external walkways, modular elements of condensers, various sensors ...) so that there is no work such as drilling holes or the like to be carried out on site. The construction materials of the tower can be brought on site by trucks moving on a bridge built on stilts from the coast to the tower and anchored on the base of it to the right of the stilts. The drain pipes of

  the fresh water is fixed under the bridge to reach the coast, as well as the cables for transporting the electric energy produced by the wind turbines arranged on the upper platform of the tower.

  FIG. 11 shows, in top view, the arrangement of the radiating rows 65 of supports for the condenser modules mounted in staggered rows. The upper rows 65 are shown in solid lines, the other rows below are shown in dashed lines. They are offset from each other so as to offer together a maximum exchange surface with the rising air moving in a wall labyrinth formed by the successive levels of rows of condenser modules. Each radiating row of modules is placed above a collecting chute 67 collecting fresh water flowing over the condensers of its row. Each level trough is connected to an annular collecting pipe, which is in turn connected to the fresh water down pipes from the drainage system to the distribution to the

  users. All of the row levels extend from the pass about 160 m above sea level, up to about 260m for a tower 300m high.

  Access to the condenser modules 80 is provided by three elevators 70 arranged 120 from one another. The step between the levels of module rows is approximately 3m. The elevators are designed to be able to stop at each of these levels and each has

  a large external bearing 71 so as to be able to discharge the condensers at each level.

  The modules of the condenser assembly are put in place when the construction of the tower is completely finished and their supports are in place. Each row of modules of

  each level is equipped with an access gateway 72 connected to an annular gateway 73 30 (fixed to the internal wall of the tower) which makes the connection between the rows of the same level.

  These gangways per row are fixed to each other at their free end by connecting arms 74 and fixed between levels by a mesh connected to the wall of the tower so as to give them overall rigidity. This structure supports the refrigerant pipes and the

  module supports. Each row has a radiating length of around 20 to 35 25m for a tower of 300m.

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  FIG. 12 schematically shows an example of assembly by row 75 of the condenser modules 80 placed on their support 81 and their connection by flexible pipes 82, 83 and quick couplings 84 to the common coolant pipe. 85. These quick couplings are fitted with a non-return valve to prevent refrigerant leakage between the common pipes 85 and the modules 80. A central deflector can be provided at the base of the condenser assembly to direct the passage of the air only on condensers. The total surface of the condenser assembly is provided to condense a total flow of

m3 / second for a 300m tower.

  We can see step 86 between the row levels. These modules 80 are produced as conventional exchangers having a maximum surface area for exchange with the ascending air. The simple condenser modules 80 have dimensions of approximately lm wide and 2.5m high, ie 2.5m2. To reduce the number of modules per level, provision has been made to be able to use double modules, ie two thicknesses bringing the exchange surface per module to Sm2. At the rate of 20 modules per row, there is a total condensation surface per 15 rows of 50 or 100m2 The energy consumed by the condenser assembly will be supplied by part of the wind turbines

  mounted on the upper platform of the tower.

  FIG. 13 shows an example of a swing to facilitate the operation of the condenser modules from the elevators by levels, in the different rows of each level. These swings move by means of a wheel 90 rolling on a fixed rail 91 with possibly a counter rail 92 to avoid any possibility of derailment. The wheel is mounted to rotate freely on an axis integral with the upper end of a bent tube 93 forming the body of the swing and comprising at its base means 94 for fitting and holding the condenser module 80. The rails and counter rail are arranged parallel to each row so as to bring the modules opposite their position on the corresponding row. The module is lifted manually and placed on its fixed support placed slightly in front of the swing. Rails and counter rails are arranged near the wall of the tower and parallel to it so as to be able to distribute the modules between the different

rows from elevators.

  The overall operation of the tower is controlled by a set of sensors including: control of the air speed at the entrance and at the exit of the tower; air humidity control at the entrance and exit of the tower; control of the temperature of the air entering and leaving the tower and in several zones of the condenser assembly; control of temperature variations at the condenser modules, between the parts of the tower exposed to the sun and the parts in the shade and control of the induced voltages;

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  sea water temperature control; freshwater flow control by level and global control for all levels; seismographic control, control of electrical energy production by wind turbines and electrical consumption by the condenser assembly. The internal equipment of the tower also includes powerful interior lighting protected in watertight boxes to facilitate construction and allow subsequent maintenance interventions on the condenser modules. Of course all the metal members used in the tower and outside are made of stainless steel. The wall crossings at the different levels to the right of the elevators for the introduction and installation of the condenser modules, and control means at the end of construction of

  the tower, are closed by watertight doors.

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Claims (10)

CLAIMS:   1) Seawater desalination tower characterized in that it is built at sea on stilts along the coast on sites at a depth between 10 and 20 meters, it comprises a cylindrical base (1) resting on piles (10) themselves arranged in abutment on an annular raft (11) which, depending on the nature of the soil, may itself be in abutment on piles (12), said base (1) being located approximately 10m at - above the maximum sea level; said tower is broadly flared at its base (1), it rises gradually narrowing to the neck (2) then flares towards its top (3), the neck, with an internal diameter d 'about 100 m for a tower of 300 10 m in height, is about 140 m in height, and the top (3) with an inside diameter of about 130 m, has an annular platform (4) of a width of approximately 15 m on which are installed wind turbines of approximately 1.5 MW each; a second platform (5) is arranged slightly above the neck (2), these two platforms   are supported by ribs (6 and 7); a condenser assembly is arranged above the neck (2) inside the tower.   2) Desalination tower according to claim 1, characterized in that to protect the site in the event of a storm, the tower is partially or totally surrounded, at a distance at least equal to the radius of the base of the tower, of a wall breakwater (26) allowing passage   water through multiple openings (35), said wall also being built on 20 stilts (36).   3) Desalination tower according to claim 1, characterized in that it is mounted in rows (R) of modules (M), prefabricated in the factory, by means for example of three cranes, of tower or jib type, placed on a horizontal row of modules and raised every 30 meters, the construction of the tower being carried out by laying and assembling modules. comprising tenons (55) and mortises (56) for their vertical assembly and tenons (57) and mortises (58) for their horizontal assembly, several modules being able to be fixed side by side by means of pre-stressed tie rods (59); each new row of modules being different from the   previous, some modules having inserts for fixing external or internal elements to the tower.   4) Desalination tower according to claim 1, characterized in that a bridge is built on stilts from the coast to the tower and anchored on the base thereof, the   fresh water evacuation pipes being fixed under the bridge to reach the coast, as well as the cables for transporting the electrical energy produced by the wind turbines 35 arranged on the upper platform of the tower. 2843383   ) Desalination tower according to claim 1, characterized in that guillotine doors (40) for regulating the air inlet or for closing off this inlet, disposed between the pilings (41, 42) of the foundation of the tower; they are each engaged in a corresponding slide (G1, G2, fig. 8) of each of the foundation piles, the operation of the doors (40) being ensured in synchronism by a system of cable chains (45) and pulleys (46) and with maneuvering means (47) for raising and lowering assisted by counterweights (48) for balancing the mass of the doors, each mounted on a bracket (49) integral with the top of the periphery of the wall of the tower at right stilts.   6) Desalination tower according to claim 1, characterized in that the condenser assembly is arranged inside the tower and above the neck by radiating rows (65) of module supports (80) of the condenser, mounted staggered by levels, offset from each other so as to offer together a   maximum surface area for exchange with rising air.   7) Desalination tower according to claims 1 and 6, characterized in that the modules   exchangers (80) are mounted in rows (75), placed on their support (81) and connected by flexible hoses (82, 83) and quick couplings with non-return valve (84), to the   common coolant line (85).   8) Desalination tower according to claims 1, and 6, characterized in that the   exchanger modules ((80) are moved on swings from the elevators by levels, in the different rows of each level, these swings moving by means of a wheel (90) rolling on a fixed rail (91) with possibly a counter rail (92), the wheel being mounted rotating freely on an axis integral with the upper end of a bent tube (93) forming the body of the swing and comprising at its base means (94) for installing and holding the module (80), the rails and counter rails being arranged parallel to each row; rails and counter rails are arranged near the wall of the tower and parallel to it so as to be able to distribute the   modules between the different rows from the elevators.   9) Desalination tower according to claims 1 and 6, characterized in that access to the 30 modules 80 of the condenser is provided by three elevators (70) arranged at 120 each   others, provided to be able to stop at each of these levels and each comprising a large external bearing (71) so as to be able to unload the modules (80) at each level, each row of modules (80) of each level being equipped an access walkway (72) connected to an annular walkway (73) (fixed on the inner wall of the tower) which connects the rows of the same level, fixed between them 2843383 them at their end free by connecting arms (74) and fixed between levels by a   mesh connected to the tower wall.   ) Desalination tower according to claims 1, and 6, characterized in that each   radiating row of modules is placed above a collecting chute (67) collecting fresh water flowing over the condensers of its row, each level chute being connected to an annular collecting pipe, itself connected to the pipes of fresh water descent from the drainage system to the distribution to users.   11) Desalination tower according to one of the preceding claims, characterized in that   that the overall operation of the tower is controlled by a set of sensors including in particular: control of the air speed at the entrance and at the exit of the tower; air humidity control at the entrance and exit of the tower; control of the air temperature at the entrance and exit of the tower and in several zones of the condenser assembly; control of temperature variations at the condenser modules, between the parts of the tower exposed to the sun and the parts in the shade, and control of the induced voltages; sea water temperature control; freshwater flow control by level and global control for all levels; seismographic control; control of electrical energy production by wind turbines and   power consumption by the condenser assembly.   12) Desalination tower according to claim 1, characterized in that the top (3) of the tower comprises an annular platform (4) with a width of about 15 m on   which is installed a set of wind turbines of about 1.5 MW.