Water desalination equipment and method

Water desalination

Hello full description

Background of the invention

This invention relates to the desalination plant of water, i.e. removing dissolved solids from seawater and brackish water. Discussions about the world's drinking and irrigation water shortages are commonplace. Entire cities in some parts of the world are vulnerable to residents leaving due to long periods of drought. The only inexhaustible source of water is hoped to be in the seas, but desalination of water in large quantities to supply major population centers and large-scale irrigation projects is considered prohibitively expensive. Many desalination units operate on the basis of reverse osmosis. In this type of unit, the desalted water is forced through a semi-permeable membrane so that the dissolved solids are removed by the membrane. Other units operate on the basis of evaporation. The main problem with the two mentioned methods is that the water obtained in the case of the evaporation method is pure distilled water, and in the reverse osmosis method it is of the same degree of purity as distilled water. By default, it contains all the minerals that were dissolved in it and removed from it. Water without any calcium or magnesium in it is aggressive toward metal pipes and other metal objects with which it comes into contact. Hence, these minerals should be added to the water

Abstract. Moreover, distilled water is tasteless and cannot be used for human consumption over a long period as it is devoid of essential minerals. Therefore, for drinking purposes, it is necessary to add an amount of minerals to transform the water from “flavorless” distilled water into acceptable drinking water. In both of these methods, the essential minerals that were present in seawater are in the salt water, which is a byproduct of the process. Therefore, the major cost in producing water from any type of unit is the cost of the minerals that must be reintroduced into the water and the equipment required for this purpose.

In the evaporation unit, the energy required to evaporate seawater is also large when the costs per megaliter of water extracted are calculated.

Reverse osmosis membranes have a composite structure, and one widely used form involves two thin layers of a complex polymeric resin that together define a path for the salt. The path has an element to induce turbulence in the flow. The element is usually a welded mesh of plastics material filanrents. A number of these membranes are wrapped in a complex manner on a central tube. The water that passes through the mentioned thin layers enters the spaces between the adjacent membranes and flows into the central tube. The tube has holes in its wall to allow the extracted water to enter the tube. The remaining brine from the seawater and most of the dissolved solids flow out of many salt passages to the tailings or to the salt extraction unit.

Those working in this field accept that there is a polarizing layer to focus on each side of each salt path and directly adjacent to each thin layer. These layers, which are multiple molecular thicknesses, contain a concentration of dissolved solids higher than the volumetric flow in the middle portion of the salt path between the thin layers. The turbulence induction element is configured to reduce the thickness of the focusing polarization layer and thus enhance the membrane's ability to allow water to pass through it. A prior art reverse osmosis membrane typically achieves a dissolved solids rejection rate of 99.3% and the dissolved solids that pass through the membrane are largely limited. From ordinary salt, its molecules are smaller than those of most other minerals. A percentage of 0.7% is approximately 400-500 ppm of dissolved solids in the extracted water, depending on the initial salinity of the seawater, and this is less than the threshold value at which dissolved solids impart a taste to the water. Reverse osmosis membrane blockage is a major problem and a criterion that increases the cost of water production that must be taken into account to prevent blockage and remove it when it occurs. Clogging can result from mineral deposition in the membrane or from organic growth. For example, before seawater reaches the membrane, the membrane is treated with an inhibitor such as sodium hexametaphosphate.

(Commonly known as “very thin water”). This limits the deposition of calcium and magnesium on the membrane in the form of calcium and magnesium carbonates, but adds another factor to production costs.

Membrane manufacturers recommend a relatively low flow rate (the rate of water flow through the membrane in liters per hour per square meter of membrane) to avoid rapid clogging. Membrane backwashing, which causes water to flow in the reverse direction through the salt passages, is a standard procedure to remove blockages.

If the membrane is heavily clogged, it should be removed from the extraction unit and subjected to a series of treatments to remove the blockage. In extreme cases, the blockage cannot be removed and the membrane must be disposed of.

As a result of all these factors, water produced from a reverse osmosis unit is more expensive than water obtained using water technology from a storage dam or river. Hence, despite the world's water shortage, only a small percentage of the world's water is produced using reverse osmosis units to desalinate seawater.

General description of the invention

The main objectives of the present invention are to improve the efficiency of the reverse osmosis process, to significantly reduce the cost of water produced by the reverse osmosis process, to prevent clogging of the reverse osmosis membranes, and to produce water containing the required minerals and without the need for treatment with a flavoring agent. According to one aspect of the present invention, a reverse osmosis desalter plant is provided that includes a filtration element consisting of reverse osmosis membranes that define salt paths, a pump for pumping the desalted water to said filter element, and a barrier from the water flow path between said pump and said filter element to introduce turbulence. vortex in the flowing water and causing a drop in pressure across the barrier, where the water after the barrier when it enters the aforementioned salt passages for the filtration element is at a lower pressure than the water present before the barrier and its flow is greater Disturbances when it is located before the barrier.

The barrier is preferably in the form of a plate with a group of holes, through which the flowing water is obstructed and divided into a number of conical and branching turbulent water streams, each of which is at a lower pressure than the water pressure present before the plate. The holes in the plate can be of different sizes or they can all be the same size as each other. The plate is preferably in the form of a circular disc, with the perforations in a spiral pattern around the center of the disc. In another model, the holes are in a circular pattern, and in another model, the holes are located along lines radiating outward from the center of the disk.

If necessary, a series of flow-restricting valves can be provided to vary the flow areas of the holes in the plate, creating individual water currents.

According to another aspect of the present invention, a method is provided for desalting water which includes pumping the water to be desalted to a filtration element consisting of reverse osmosis membranes that define salt passages, creating a pressure drop in the water flowing to the filtration element and simultaneously introducing turbulence into the water flow and feeding the turbulent water. At low pressure on the salt passages of the filter element.

In a preferred model, the water is divided into a group of turbulent water streams that are branched and cone-shaped by the aforementioned barrier, which reduces the pressure and introduces turbulence, and each turbulent stream impinges on the filtration element.

It has been found that inlet pressures that are in the range from 50 to 65 bar and pressure drops that are between 1.5 and 2 bars give the best results.

The unit and method according to the present invention extract water that has acceptable levels of dissolved solids, i.e., minerals present in it. There is no need to treat the extracted water with a flavoring agent as it itself contains sufficient dissolved solids to give it an acceptable taste. Due to the presence of magnesium and calcium in the extracted water, it is not aggressive against metal pipes and fittings, and there is no need to treat it with a substance to give it taste in the presence of these metals.

It is believed that the thickness of the focusing polarization layer is reduced by introducing water flowing in a turbulent manner in the salt lanes of the membranes. This enables the flow rate to increase without excessively increasing the blockage. Another phenomenon is that minerals are allowed to pass through the membrane in addition to the common salt while the amount of common salt in the extracted water is not increased to an unacceptable level. Experimental work has shown that by varying the pressure drop and turbulence, such as the different sizes of holes in the plate when it forms a barrier, the passage of various dissolved solids through the membranes can occur in controllable quantities. Hence, by trying and experimenting, that is, by varying the pressure drop and turbulence, it is possible to extract dissolved solids in pre-determined quantities. Another benefit is that experimental work has shown that membrane clogging can be significantly reduced when turbulent water is fed to it.

The salt water coming out of a conventional reverse osmosis unit is heavier than seawater and will sink if fed back to the sea. However, the brine that exits the desalter unit according to the present invention essentially rises when fed back to the sea in the form of

Ascendant instead of gon. It has been found that salt water is mixed with air, and it has been found that the aeration agent is oxygen. Moreover, there are oxygen bubbles in the extracted water.

Tests show that there is more oxygen in the extracted water and in the salt water than there should be based on the amount of oxygen dissolved in the seawater. The oxygen bubbles are small, as there is an actual pressure beyond the barrier, of 45 to 50 bars, for example. It is believed that small bubbles in turbulent water play a role in reducing the thickness of the focusing polarization layers. Bubbles also appear to play a role in preventing membrane blockage.

Brief explanation of the drawings

To better understand the present invention and to show how it is implemented, it is now given by example to the attached diagrams in which:

Figures (1a) and (1b): Together they form an axial section through the desalterization unit that forms part of the desalination facility;

Figure (2): A sector taken at the same level as the sector of Figures (1a) and (1b) and shows one of the peripheral parts of the unit on a larger scale;

Figure (3): The original location of the disk;

Figure (4): A section cut at the same level as Figure (2) and to the same scale, and shows a modification of the unit found in Figures (1a) and (1b),

Figures (A) and (EB) show other tablets;

Figure (6): A schematic cross-section through a manually operated water desalination unit.

Figure (7): Schematically showing a motor-driven desalination unit.

Figure (8): Schematically showing a desalination unit as well.

Figure (9): Schematic representation of a submersible desalter unit.

Figure (10): A schematic drawing showing a plan for a water desalination unit.

Figure (11): shows a submersible desalterization unit.

Figures (12a) and (12b): together show the desalination unit that is located inside a single outer shell.

Figure (13): shows a floating desalterization unit.

Figure (14): shows a tank and the piping system connected to it.

Detailed description

Referring to Figures (1a) and (1b) at the beginning, we find that the desalination unit shown is generally identified by the reference number (10) and includes the cylindrical cover (12) with the two end covers (14) and (16) installed at its opposite ends. The inlet pipe (18) for water containing dissolved solids passes through the end cap (14) and feeds the water to the chamber (20). The pipe (81) is connected to the pressure side of the pump (not shown in Figure (1a)) that is capable of transporting water

At about 50 to 60 bar. The salt water outlet pipe (22) exits the chamber (24) through the end cover (16). Edge seals (26) and (28) surround the end caps (14) and (16) and a seal between the caps (14) and (16) and the casing (12).

The reference number (30) generally specifies a reverse osmosis filter element that fits tightly in the housing (12). The element (30) includes the core assembly (32), which includes the central tube (34), which forms the outlet for water extracted from the filtration element (30), and the tube (34), which contains a group of holes (36), passes in it at one end through End cap (16). The other end of the tube (34) is extended into the solid sleeve (38) (see also Figure (2)) which is provided for this in the disc-shaped bearing plate (40). The disc (40) and lid (4) form the confining walls of the chamber (20). The flange seal (42) surrounds the disc (40) between the disc (40) and the casing (12). There is a gap (see Figure (2)) between the disc (40) and the filter element (30).

The filtration element (30) in addition to the core assembly (32) includes a semi-permeable membrane that is draped over the core assembly (32). The coiled membrane fills the entire space between the core structure (32) and the inner surface of the casing (12) and fills the space between the disc (40) and the chamber (24), regardless of the gap between it and the disc (40).

A commercially available form of the filter element suitable for use in the present invention is one produced and sold by Filmtec Corporation, a wholly owned subsidiary of The Dow Chemical Company. The product bears the designation FT30. And describe

US Patent No. 4,277,344 details the membrane that operates on the principle of reverse osmosis. The language of the filter element membrane (30) is complex. It is essentially formed as a series of planar cavities which are then wound onto the core structure (32) in a superposition relationship. The disk (40) (see Figure (3)) includes a series of eight holes 44.1, 44.2, etc. in it. The holes vary in size, and in the model shown, holes of sizes 8805 mm, 9185, 8077 mm, 7772 mm, 7675 mm, 7351 mm, 7094 mm, and 881 mm are used. The diameter of the disc (40) is about 20 cm and is also the inner diameter of the casing (12) and the outer diameter of the filter element (30).

Behind the disk (40) and between it, between the coiled membrane, are the cross lines (46) (shown in the circumferential line in Figure 3), which include a central hub, an outer ring, and a group of

The bars that fit between the hub and the ring. The cross lines (46) are part of the filtration element, as is available from the company, and define a series of wedge-shaped openings. Each hole 44.1 and 44.2 is in line with one of those holes so that each water stream impinges on the filtration element.

When water flows under pressure through a hole restricted under pressure, the water stream exiting the hole expands outward into a cone shape and then breaks up into droplets at a distance from the hole. The conical portion of the water stream between the hole and the point where the stream breaks is itself a turbulent point containing eddy currents and eddies in it. The filtration element (30) is placed so that the streams of water coming out of the holes 4401...etc. hit the filtration element and flow into the passages.

Salt before we break into sprinkles of droplets. Cracking is prevented in the unit shown because the gap between the disc (40) and the element (30) is filled with water under pressure immediately after the water begins to flow.

The applicant has discovered that the water fed at the specified pressures mentioned in filtration element (30) does not contain 99.3% of the dissolved solids removed, but a low percentage is removed. Using an inlet pressure of 50 bar and a dial (40) as previously mentioned, the system desalinates seawater and turns it into potable water that meets the standard found in the South African Bureau of Standards 241-1984 AD.

Pressures are obtained in a range from about 48.5 bar to 49.5 bar after holes 44.1, 44.2, etc., with a pressure in chamber (20) of about 50 bar. The applicant also discovered that there was a very slight increase in temperature across the disc (40) and assumed that this resulted from the introduction of turbulence into the flow.

The structure of Figure (4) differs from the structure of Figures (1a) and (1b) and Figures (2) and (3) in that different pressures are achieved on the subsequent side of the disc (40) by placing valves in an annular arrangement to control the water flow (48). The valves (48) include locking or detaining means to vary their effective flow areas, and together they include a barrier that introduces turbulence and causes a pressure drop. Each valve (48) has a control cable (50) leading to it, and each valve (48) is in a pipe (52). The tubes (52) are the same diameter as each other and pass through the disc (40). The valves (48) are operated electrically and the degree to which they are opened can be controlled from an adjustable control unit

For programming. The position of each valve (48) determines the pressure at the outlet of the corresponding pipe (52). The pressure can be varied by the TDS control unit to vary depending on demand. While the valves are located posterior to the disc (40), they may be in a usable combination inside the disc and exiting near holes in the disc

The disk (40) in Figure (3) contains holes in it arranged in a ring arrangement. And be

The holes in the form (HB) are in a helical arrangement concentric with the disc. The spiral pattern is wound in the same direction as when the filter element (30) was wound, and the holes are placed in a number of diagonal lines. The holes in Figures (A) and (HB) are yellower than the holes shown in Figure (3) and are more numerous.

Referring now to Figure (6), we find that the manually operated water desalination unit (54) shown includes a cylindrical casing (56) that contains within it a commercially available filtration element (58) like the element mentioned previously and identified by the reference number (30) in both figures. (1a) and (1b)• A seal (60) surrounds the filter element (58) to prevent water leakage between the casing (56) and the filter element (58). The disc (62) is located next to one of the end surfaces of the filter element (58). There is a seal (64) between the disc (62) and the cover (56). Movement of the disc (62) to the left is prevented by the retaining ring (66).

The holes in the disc are not indicated (62). There is a gap between the disc (62) and the filter element (58).

Next to the other end of the filter element (58) is the end cover (68), which includes a central hole threaded from the inside (70) through it and through the secondary hole (72), which is on one side of the hole (70).

The filter element (58) is shown as it contains the central tube (74) that protrudes into

Opposite directions of its coiled membrane. One end of the tube (74) rests in a solid cavity (76) in the disk (62) and the other end of the tube (74) enters the hole (70) of the end cap (68). The opening (72) is in communication with the chamber identified by reference number (78) which is located between the end cap (68) and the end adjacent to the filtration element (58). The filtration element (58), disc (62), and end cap (68) are as shown in Figures (1a) and (1b), and then these components form the desalterization unit (10). To the left of the disc (62), the housing (56) forms a cylinder for the piston (80). The piston (80) includes the rod (82) and exits the housing (56) through the sealing fitting identified by reference number (84). The cross lines (86) hold the sealing composition (84) in place.

The flange seals (88) and (90) and the &O-ring (92) surround the piston

(80).

The operating handle (94) is connected to the rod (82) by a sliding coupler (not shown). The handle (94) is trunnionally connected to the end plate (98) on which it is fixed

The same with the lip (100) of the cover (56). By swinging the handle (94), the piston (80) can be moved reciprocatingly in forward and backward strokes in its cylinder.

The hole (72) is connected to the pipe (102) with the chamber (104) that surrounds the rod (82) and prevents leakage with the fitting (84).

A one-way valve (106) allows water to enter the chamber (108), which is between the disc (62) and the piston (80). The valve (106) is installed in the hole in the casing walls (56) and a pressure relief hole (110) is also provided in the casing walls (56). An outlet pipe (not shown) is screwed into the threaded hole from the inside (70), and potable water extracted from the pipe (74) flows into this outlet pipe. When using the desalination unit shown in Figure (6), the casing (56) is installed with the valve (106) submerged in the salt water or brackish water from which the salt is removed. The upper end of the handle (94) is pushed or pulled to the position shown, which moves the handle (80) on its return stroke. When the piston moves to the left, the valve (106) opens and brackish or salty water is drawn into the chamber (108). When the handle (94) is pushed to the left, the piston (80) begins its working stroke and moves towards the disc (62). The valve (106) closes the pressure that rises in the chamber (108) immediately. The water in the chamber (108) is pushed through the holes in the disk (62) through the filtration element (58) and out of the filtration element as drinkable water through the pipe (74) or as salt water through the hole (72) and the pipe.

(102). The piston (80) continues to move to the right until the lip seal (A9) of the valve (106) is passed.

After a few strokes of the handle (94), pressure begins to build up in the pipe (102) and then in the chamber (104). The forward stroke of the piston (80) is ultimately assisted by pressure in the pipe (102) and chamber (104). When the piston (80) reaches the front end of its stroke, the lip seal moves beyond the pressure relief hole (110) and the pressure in the chamber (104) decreases. Therefore, the return stroke of the piston (80) is not resisted by any pressure in the chamber (104). The pressure required to push water through the filtration element (58) and separate it into drinking water and the salt water stream is in the range of 15 to 25 bar (for brackish water) and 50 to 60 bar (for sea water). The required pressure varies depending on the amount of solids dissolved in the water. The pressure loss in the filtration element (58) is relatively small, and the salt water pressure in the pipe (102) can be from 75% to 85% of the pressure that exists when the water enters the filtration element (58). This excess pressure that would otherwise be lost is used as mentioned to help operate the pump.

Converting now to Figure (7), we find that the desalterization unit shown includes the casing (112) which is placed vertically. The ends of the casing are locked with the end caps (114) and (116), and there are sealing rings (not shown) between the end caps (114) and (116) and the casing (112). Directly under the cover (114) are the chamber (118) and the disc (120). And there is under

Disc (120) Filter element (122). There is a gap (124) between the disc (120) and the filter element (122).

The filtration element (122) includes the central tube (126). The position of the upper end of the tube (126) is determined by the dial (120) and the position of the lower end of the tube (126) is determined by the end cap (116). The entrance pipe (128) leads to room (118). The salt water outlet pipe (130) is connected through the end cap (116), and the potable water outlet pipe (132) passes through the end cap (114) and connects to the upper end of the pipe (126). The disc (120) is in the general shape shown, for example, in Figure (3), Figure (H-A), or Figure (H-B). The aforementioned components form the desalination unit (10). A vertically positioned Groenfoss pump (134) has a suction inlet (136) connected by a filter (138) to a pond or other source of water from which the desalination is done. The pipe (128) is connected to the pressure hole of the pump (134), and there is a control valve (140) in the pipe (128).

The pipe (130) is connected via a T-shaped piece (142) and the control valve (144) with the Pelton turbine (146). The other end of the T-shaped piece (142) is connected via the control valve (148) to the waste outlet (150) from which the salt water is drained into the waste. The exit side of the Pelton turbine (146) also drains to waste. The pump motor (134) is identified by the reference number (152). Its electrical source may include, alternatively, a direct connection to a 220 V main line or a connection to a solar panel.

(154) or battery (156) and adapter (158). The supply circuit provides a control unit (160) to be able to change the rate at which the motor is driven.

The central shaft of its Belton assembly is connected to the drive shaft of the engine (152). As previously explained by referring to Figure (6), there is a decrease in pressure inside the filtration element (122), but the salt water coming out of the filtration element (122) remains at a pressure to some extent. By feeding some or all of the salt water under pressure through the Pelton turbine, the power requirements of the engine (152) can be reduced by using some of the pressure energy that would otherwise be lost. In Figure (8), a unit is shown that is similar to the unit in Figure (7), and similar parts have been identified with similar reference numbers. In this model, the water to be desalted enters from the lower part of the casing (112) instead of the upper part, and the pump and motor (identified by reference numbers (162) and (164) respectively) do not form an integrated unit. Instead, they are installed side by side using their base plates (166) and (168). The pressure input to the casing specified by the reference number (112) is through the pipe (128). The desalted water exits through the pipe (132) and the salty water exits through the pipe (130). The Pelton turbine (146) helps drive the pump (162).

The desalterization unit shown in Figure (9) includes the vertical main casing (170) which is positioned at the bottom of the orifice hole containing brackish water therein or at the bottom of the pond containing seawater. The pump is indicated with the reference number (172), and the motor that runs the pump is indicated with the reference number (174). The pressure side of the pump is connected to...

Chamber (176) The upper end of the chamber (176) is formed by the disc (178). The filter element (180) is located above the disc (178).

The end cap (182) is located above the filtration element (180), which surrounds the chamber between it and the filtration element (180). The salt water coming out of the filtration element (180) enters this chamber, and the water extracted from the filtration element (180) comes out through the pipe (184). The Pelton turbine (186) is installed on the casing (170) above the end cap (182). The chamber between the end cap (182) and the filter element (180) is connected by pipe (188) to the Pelton turbine. It will be perceived that there is a lot of pressure in the room. The salt water entering this chamber is fed under pressure from the filtration element (180) through the pipe (188) and Pelton turbine (186) to the drain pipe designated by the reference number (190). The Pelton turbine (186) drives the pump (not shown). The pump is axially aligned with the Pelton turbine (186) and the pipe (184) is connected to the pump. The purpose of driving the pump in a Pelton turbine is to raise the extracted water up to ground level via a hollow shaft (192) (if the casing (170) is in a drilled hole) or up to the surface of the pond (if the casing (170) is immersed in a pond salty water).

Power is delivered to the motor (174) from an array of solar panels (194) that are used to charge the batteries (196). The 220 volt source is indicated at the reference number (198). This is connected to a solution to reduce the voltage and a rectifier (200). It is also connected to the control unit (202) through which power is fed to the motor (174). Paintings work (194)

The rectifier (200) charges the batteries (196). The output from the batteries (196) is fed through the converter (204), which converts the 12 volts DC output of the batteries into 220 volts bar AC. A transfer switch (206) takes power from the adapter (204) or from the power source (198) depending on the amount of energy available in the batteries. The control unit (202) increases the input voltage of 220 volts to an output voltage of 380 to supply the motor (174).

The advantage of the unit in Figure (9) is that only the extracted water is raised to the surface. The unit shown in Figure (10) includes a housing (208) with a filter element (210) therein. The entrance to the desalted water is at the reference number (212), and the outlet for the salty water is indicated at the reference number (214). The outlet for the extracted water is indicated at the reference number (216). The means that lead to a decrease in pressure before the filtration element (210) and to create streams of water that impinge on the filtration element (210) are explained, as found in the model shown in Figure (4).

The source of the water whose salinity is removed is indicated at reference number (218), and the pool of water can be a sea or a source of brackish water. The technology pump is indicated at the reference number (220), and it extracts water from the source (218) and feeds it through the sand filter (222) and the disc filter (224). A high-pressure pump is indicated at reference number (226), and its suction side is connected to the filter (224) and the pressure side is connected to the inlet (212).

The outlet (216) is connected to the vessel (228) in which the extracted water is subjected to ultraviolet rays (77). Exposing water to ultraviolet rays is a standard procedure for water purification. The outlet hole from the vessel (228) leads to the storage tank (230). If the unit is not operated for a period of time due to the presence of insufficient extracted water in storage, there is a risk of bacteria and algae growth in the element (210). This can only be avoided by continuous circulation of water through element (210). For this purpose, the tank (230) can be connected via the pump (232) and valve (234) to the inlet (212). The valve (236) is closed when the valve (234) opens. Using this circuit, the extracted water can be continuously circulated through element (210), thus ensuring the prevention of bacterial growth. Where the pressure produced by the pump (232) is relatively low, “washing” is performed, but the pressure is insufficient to push the water through the membranes and then into the tank (230). The water used for washing purposes is drained to the waste.

The salt water outlet (214) is connected to the Petlon turbine (268) so that the benefit is taken from the remaining pressure after the filtration element (210). The Petaloun turbine can be used to pump extracted water, to generate electricity, or to help turn the rotor of any of the pumps (220) or (226). Flow switches (240) that detect when flow is occurring in the pipe in which they are installed, and flow meters (242) that detect flow rate may be included. The pH and conductivity of the extracted water can also be measured (at reference numbers (4 22) and (46 2)). All inferred information is fed to the main control unit (48 2) which exercises comprehensive control over the system.

Other valves are indicated to enable the pipes in which they are installed to be closed at the reference numbers

(250), (252), (254), (256), (258), (260), (262), and (264).

To backwash the disc filter (224), valves (234) and (250) are closed and valves (236) and (262) are opened. Water is thus drawn from the tank (230) by the pump (232), fed through the open valve (236), pushed through the filter (224) in the reverse direction, and discharged to the waste through the open valve (262). A level detector (266) can be used in the tank (230) to determine when the tank is full. The resulting signal can be used to stop drawing water from the source (218) and to start recirculation through the pump (232) and valve (234) to avoid bacterial growth.

The torque of the Pelton turbine (268) can be controlled by including a torque detector (270). If the torque exceeds the predetermined level, the valve (256) opens so that some of the salt water bypasses the Pelton turbine (268) and flows directly to the waste through the valve (256). The positions of the valves that control the flow of water to the filtration element (210) can be controlled using the keyboard (272) of the type used with personal computers. The facility shown in Figure (11) includes a desalination unit (10) placed vertically as shown in Figure (1) and standing vertically in the pond (274). Similar parts are identified with similar reference numbers. The entry of the de-salted water is indicated at the reference number (18), the outlet for the de-salted water is indicated where it is connected to the pipe (34), and the outlet of the salty water is indicated at the reference number (22).

The pump is shown at reference number (276) in Figure (11). The pump (276) is a vertically driven impeller pump with its inlet at the upper end and its outlet at the lower end.

The outlet pipe is identified by the reference number (278) and there is an auxiliary pump (280) in the outlet (278). The pump motor (280) is connected to the solar panel (282). The function of the pump (280) is to initiate flow through the driving pump (276). We do this by suctioning water through the impeller pump (276) and draining it through the outlet pipe (284). The pump (276) includes flow control valves (286) and (288), one of which is located at the upper end of the pump and the other is located at the lower end of the pump. When the pump (276) is started, the subsequent flow generated through the pump (276) pulls the valve (286) to the open position and pushes the valve (288) to the closed position. When the valve (288) closes, a shock wave is sent through the pump (276), and the shock wave forces water under high pressure through a one-way valve (290) to the inlet (18) of the casing (12). There is another one-way valve (292) in the inlet (18).

The retaining device (294) is connected to the valve (290). When the valve (290) opens, the retaining device is pushed through the dead center position. Once the pressure shock is dissipated, the retaining device (294) is effective in re-locking the valve (290).

The valves (286) and (288) are connected by the rod (296) and thus move in harmony. Once flow is initiated through the driving pump, you must stop the pump (280) and leave it in

An open state such that flow can occur through it. The column of water in the pond (enclosed by the side wall (298) and bottom wall (300)) ensures that the pump (276) continues to rotate.

The remaining pressure of salt water in outlet (22) can be used for any of the purposes mentioned previously.

Preferably, the wall (298) separates the pool (274) from the sea. When there is a high tide, water flows over the top of the wall (298) and fills the pool (274). This provides the required operating pressure for the pump (276). When the tide is low, and there is no more water entering the pond, the level in the pond is steadily lowered as the water flows away through the impeller pump (276) and outlet pipe (284).

The submersible desalter unit shown in Figures (12a) and (12b) includes a cylindrical feeder (302). Inside the casing and at one end is the electric motor (304) that drives the pump (306). The pump (304) can be of any suitable type, such as a piston pump, a differential pump, etc. The salt water inlet to the pump (306) is not indicated, but the pump outlet is identified by the reference number (308). The outlet (308) is divided into two branches (310) and (321), and valves (314) and (316) are located in branches (310) and (312). The branch (310) leads to the core of the disc filter (318) which is included in the cavity (320). The disc (322) forms one of the boundaries of the cavity (320) and the filter element (324) is located on the other side of the disc (322). The disk (322) could be as previously described with reference to Figures (1a) and (1b).

(2) and (3) or form (4) or forms (HA) or (HB). The holes in the disc are not indicated (322).

The branch (312) leads directly to the cavity (320) and the outlet (326) extends from the filter core (318) through the disc (322). The outlet (326) has a valve in it (not shown) that is usually closed. The disc filter (318) can be cleaned by closing the valve (314) and opening both the valve (316) and the valve at the outlet (326). Water thus flows into the cavity (320) and from the cavity (320) through the disc filter (318) in the reverse direction and out through the outlet (326) carrying away any dirty particles that have been trapped in the disc filter (318). Inside the jacket (302), the extracted water is subjected to ultraviolet rays in the unit (328).

As previously described, the brine can be fed back to the motor and pump so that its remaining pressure can be used to reduce the power requirements of the motor (304). The power source for the motor (304) can be as previously described by referring to Figures (7) and (9), for example.

The floating desalter unit shown in Figure (13) includes a housing (330), a mounting block (332) fixed to the sea or simply resting on the seabed, and a mounting cable (334) that connects the housing (330) to the mounting block (332).

The horizontal separator (336) divides the flotation space (338), which is above the separator (336), from the water entry chamber (340), which is below the separator (336). Holes (342) in the housing (330) allow seawater to enter the inlet chamber (340).

An electric motor (344) is installed so that it is largely located inside the room (340), and thus...

Cooling it with sea water that flows into the chamber (340). The pump (346) is installed above the engine (344) and is driven by the engine (344). Water is drawn by the pump (346) from the chamber (340) through the filter (348).

The pressure opening of the pump (6 34) is connected to pipes generally designated as reference number (350) with three units (10) of the type shown in Figures (1a) and (1b). While 3 units (10) are indicated inside the housing (330), any suitable number can be used, starting from one and above.

The highly saline water comes out of units 10 through the pipes designated by the reference number (352) and is drained to the waste through an outlet designated in a general shape by the reference number (356) and passes through the ultraviolet unit (358) to reach the outlet (360). The pipes (not shown) run from the outlet (360) to the shore, and in the model shown, the electrical cable (not shown) runs from the shore to deliver power to the engine (344).

At the upper end of the housing (330) is a solar panel (362) that is used to deliver lighting power and a wireless transmitter generally identified by the reference number (364). This is prepared to warn passing ships of the danger posed by the floating unit.

To make this unnecessary in supplying power to the unit and to enable the motor (344) and pump (346) to be mounted, a piston pump may be provided between the housing (330) and the mounting block (332). Very specifically, a rod (not shown) can be extended downward from the housing (330) and has a piston at its lower end. A cylinder is mounted on the mounting block (332), and the piston is inside the cylinder. The piston and cylinder form the pump which can be double-action or single-action.

It will be realized that the housing (330) will rise and fall over a distance that depends on the amount of bulges passing through it. When the housing (330) rises, it raises the piston rod and piston relative to the cylinder which is prevented from rising by the mounting block. The reducing chamber of the cylinder in the body is thus increased and can be filled with seawater through a non-return valve. When the housing (330) is lowered into the space between two bulges, the piston moves down the housing and reduces the volume of said lower chamber. Another one-way valve opens under the influence of increased pressure in the lower chamber, and seawater is pushed from the lower chamber into the piping system (350). If necessary, the piston rod can be hollow, thus forming a flow path from the lower chamber to the system (350).

The upper chamber of the cylinder can easily be opened to the sea. However, it is preferable to also have a one-way inlet valve and a one-way outlet valve so that water is pumped out when the piston is lowered relative to the cylinder and when it is raised relative to the cylinder.

Referring finally to Figure (14), we find that the reference number (366) identifies the vertically extended tank that includes the seawater inlet (368) through which seawater is pumped into the tank. The tank is open at its upper end to provide air ventilation (370). The outlet (372) is connected to the suction inlet of the pump that feeds water to the unit shown in Figures (1a) and (1b). The outlet of the water extracted from the unit in Figures (1a) and (1b) is connected to the inlet (372) of the tank (366), so that water with a low concentration of dissolved solids in it is returned to the tank (366). Another exit is indicated at the reference number (375), and this enables the tank and the solid materials present in it to be emptied in order to be removed. The vertically extended statement bottle is indicated at the reference number (376).

When the desalination unit, of which the tank (366) is a part, starts operating, this tank is filled with a volume of extracted water approximately equal to one-third of the volume of water it ultimately contains. Seawater is pumped into it through the inlet (368) and extracted water is fed into it through the inlet (372). Water is then continuously sucked from the tank (366) through the outlet (372). The seawater entering through the inlet (368) is diluted before leaving the tank through the outlet (372). It has been found that although some of the extracted water is recycled and not all of the extracted water is removed in the case from the unit, the total extracted water discharge is increased and lower pressures are required to ensure that unwanted dissolved solids are removed from the water.

Experimental work has shown that while extracted water with a low dissolved solids content can be fed through the inlet (372), it is preferable to use a conventional desalter unit.

Which provides water that is of the same quality as distilled water as the source that is connected to the inlet (372).

It has also been found that water produced by the method and device of the present invention can contain small amounts of salt water added to it without this increasing the overall salt content to undesired levels. This procedure can be used when conditions exist where, for example, a sufficient amount of a mineral cannot be left in the water. Supplementing the mineral that is not present in sufficient quantities by adding a salt solution is a possible way to achieve the required mineral balance.