The invention provides a method of producing high quality potable water at a greatly reduced cost nsing an Archhnedian desalination assembly to be described herein.

PRIOR ART There is no optimuta of universal process for demineralisation of the various feed waters. Each so-called contaminated or modified feed water supply must be evaluated for its peculiarities and optimal process for purification for a speci end use. As established by the U. S. Public Health Service, water for human consumption should contain no more than 300 to 500 parts per million. of dissolved solids. To achieve that a secondary purification process may be introduced, using known technology in the form of reverse osmosis or thermal desalination combined with selective chemical and ultra violet treatments depending on the contamination of the feed water.

The partial or almost complete demineralization of sea and brackish waters, geothermal brines, wastewaters, and industrial luents to make fresh water stable for human or animal consumption, divetse mdustrial uses, irrigation, recreation or aquifer recharge is broadly referred to as desalination.

Desalination is a process of removing dissolved salts notably sodium chloride, from. seawater, bore water and brackish water to yield potable water for human. consumption, irrigation and industrial purposes. As the earth's population grows, the demands on water resources increase not only by domestic consumption, but also an associated agricultural and industrial. water demand.

Concurrently, water resources are being depleted by declining water tables, by pollution of surface cources, and the ever increasing salinity of ground and river waters.

While the plants for desalination of seawater, bore and brackish water are becoming economically competitive compared with the cost of transporting fresh water over long distances, the capital investments of the desalting plants which consume large quantities of energy and require continuous maintenance reduce its feasibility. In the mid 1970's, there were approximately 700 desalination plants with a capacity totalling about 250 million gallons per day located throughout the industrial world The largest of these is in the Netherlands, having a capacity of 7. 3 million gallons per day.

In various f¢ilities"e. g. plants and mare structures, agricultural land, in inland areas, islands and desert regions, it is difficult to obtain suitable water for industrial use, drinking water or agricultural water, and in many cases, it is necessary to transport water by ship or truck or to lay water supply pipelines.

Some desalination plants use, a membiane or other types of desalination apparatus that necessarily consume a targe amount of e ! ectric energy.

Thermal or nuclear power plants reuse high-temperatmie waste heat to generate electdcity from steam turbunes. Many plants or other facilities having a waste heat source as stated above require demineralized water or water having a low impunty content to operate. The technique of transporting such water by ship, land vehicle or pipelines suffers from the problem that the cost of transportation, the construction costs and maintenance and management costs are high.

Membranes or other types of desalination apparatus consume a large amount of electric energy, and this also contributes to high operation costs.

In order to efficient ! y desalinate saline or hard water, vacuum evaporation type desalination apparatuses in particular, those which use a flash system or a multiple-effect can system have been proposed. Conventional flash or multiple- effect desalination apparatuses suffer from the disadvantage that the amount of water used for cooling in condensers is large, and the amount of water discharged is correspondingly large, resulting in the need for a great amount of pump power.

In a flash system, if the difference in temperature between a heat source used and cooling water is small, efficiency becomes low. The conventional multiple- effect system suttee from the disadvantage that if a temperature difference between a heat source used and cooling water is small, it is impossible to increase the number of cans used to ffirrn a multiple-effect desalination apparatus. Accordingly, it is difficult to improve efficiency.

Because both me systems use a continuous operation : mode, it is necessary to run a fluid transfer pump and a vacuum pump at al. 1 times consuming a large amount of power, reducing efficiency. A large capacity vacuum pump which consumes a large amount of pow is rçquired. in the past, several processes for removing salt from water have been proposed, of tb. ese, distillation is the oldest and. the most common desalination process

enjoyed. The principal pmviously tcnown processes used may be summarised as follows : Flash Desalination; Multiple-effect Multistage Flash Desalination ; Vapour Reheat Flash Desalination; Multiple-effect Evaporation Vapour Compression DesalinaHon ; Solar DesaUnatton ; Humidification Solvent Extraction ; ElecUodialysis; Reverse Osmosis; Hydzate process; Direct Freezing - Vapour Compression ; Direct Freezing Secondary Refrigeration Exchange.

Thus, in the past a diversity of approaches were used for the separation of water from saline solutions. Thermal processes effect separation by means of phase changes and include distillation and freezing processes. In the membrane processes, one or inon ? suitably designed organic membranes accomplish the separation process. In a single membrane design, reverse osmosis pressure forces the fresh water through me membrane, m eleotrodialysis, a system using multiple membranes and direct current leads to formation. of pure water and brine streams and drives the salt ions toward the electrodes through charge- selective membranes. In the ion exchange process, substances are added to exchange the ions in the solution or to precipitate the salts. There are also chemical processes. In the solvent extraction process, chemicals with greater affinity for water can remove the wastes. from solutions.

As an altemative to the abovementioned processes in recent years several new approaches have been investigated, namely hydrocyclone, rotary vacuum distillation and desalination such as are disclosed in the following patents/ patent applications which are incorporated by reference herein : WO. 02/076622 A1, US5337899, US 6436298, US 2002/0189987, US 55341. 18, US 6500345 and UK 812,891. However, none of the processes described in those documents are able to reduce the initial investment cost or to diminish the continuous maintenance needed to maintain an economic operation.

United States Patent 4, 230, 364 disclose$ a rotary reverse ultranlttation osmosis apparatus and method having first and second rotors revolving in thé same direction about a central axis. The Srst rotor revolves at a higher speed and has an impeller which serves as a feed pump for the feed fluid. The second rotor revolves at lower speed and has a pressure vessel containing semi-permeable membranes which selectively permeate one component of a Iced Buid, and has an integral disused casing for the feed pump. This arrangement reduces disc friction and diffuser hydraulic tosses compared to conventional centrifugal machinery with stationary casings. The membranes are arranged so that centrifuge action within the rotating membane assembly inhibits fouting and concentration n polarization by differential buoyancy effects. The impeller can be centrifugal type with an extemally surrounding diffuser, or it can be in an external impeller tpe cnclosing a pitot tube pump type diffuser. Concentrate fluid energy can be recovered by using tangentially disposed nozzles mounted on the second rotor to discharge fluid backwards. Permeate fluid energy can be recovered from penneate nozzles ejecting permeate fluid against an impulse turbine mounted on a third rotor journalled to rotate about the axis at a speed of about one-half of the speed of the second rotor.

One disadvantage of this arrangement is that it has a complex system of moving components and is expensive to maintain and operate.

In another example of a. prior art system. United States Patent 4, 333, 832 discloses a rotating solution separation system wherein salt water and other solutions are accelerated in a rotating structure and applied to a catmister containing reverse osmosis membrane material. The desalinated water is removed after passing through the large surface area concentration of membrane material in the canmstef. The enriched brine is removed from the cannister at a point furthest from the axis of the rotating structure and returned to me vicinity of the axis to prevent the build up of dense material. The membrane material is configured in the cannister so that the fiow is generally radial with respect to the axis of me rotating structure.

This arrangement al : t0 has the disadvantage that it is expensive to operate and to maintain due to the use of moving parts. <BR> <BR> <BR> <P>In tn an example of known reverse osmosis desalination. United States Patent 4,886, 597 discloses a centrifugal reverse-osmosis desalination apparatus for removing salt from seawater. The apparatus operates on the principle of reverse- osmosis whereby a feed solution containing seawater is separated into a product solution of decreased salt concentration and an exhaust solution of increased concentration. An evacuated enclosure is included to reduce windage losses and power consumption. Reverse-osmosis is a high pressure process, e.g., 800 psi in the case of desalination of seawater. Traditionally, there have been two techniques for developing this high pressure, namely, high pressure pumps and centrifuges. Althoq&num i a centrifuge offers theoretically higher efficiencies, comniercial systems, almost without exception, have employed pumps. <BR> <BR> <BR> <P>Fractical difficulties have prevented widespread development of centrifugal . reverse-osmosis desalination systems. One'of these difficulties is the design of a membrane configuration suitable for a centrifuge For example, U. S. Pat No.

3,669,879 proposes various. rneans for deploying a reverse-osmosis membrane within a single cylindrical ! rotating pressure vessel.

U. S. Pat. No. 4, 333,832 by Siwecki et al employs, on the other hand, a number of smaller pressure vessels bcaied about the periphery of a rotating structure or rotor. Each vessel contains a single cartridge of reverse-osmosis membrane material This is a poetical design but t is feasible only for relatively large rotor diameters.

Desatination arrangements have been proposed wherein a single solution is separated by means of a reverse-osmosis membrane, into two solutions ; one of higher and one of lower concentration than the original solution.

In another example of the prior art apparatuses, United States Patent 5,137,637 discloses a rotation high flux membrane device comprising a spiral wound membrane module for use in separating at least part of one component from a feed stream, the mo<iule comprising : a generally-hollow rotatable shaft having a means for supplying a feed stream; a means capable of rotating the shaft about its axis of totation; two permselective membranes affixed to the shaft and spaced &om each other by a permeate spacer to provide a first membrane channel therebetween ; a feed spacer disposed about the exterior surfaces of the permselective membranes such that a second membrane channel is formed when the permselective membranes are spitally wrapped around the sham in overlapping eMonship one upon the other ? form a compact membrane roll ; a means for removal of a permeate stream from the first membrane channel to the exterior of the membrane module ; and a mens for removal of a retetitate stream from the second membrane channel to the exterior of the membrane module.

The apparatus described in that patent is complex to operate and manufacture and has a large number of moving parts which require high maintenance. This makes the apparatus expensive to construct and maintain thereby reducing the overall @@ economic efficiency of the system Also, the system squires membranes for separation of the unwanted effluent from the product and involves spinning of the membranes disposed about a shaft.

United States Patent 6,833,056 discloses a desalination method and desalination apparatus capable of obtaining fresh water smbly at al. leged low cost by utilizing low-temperature waste, wherein the desalination apparatus includes a heat exchanger cooperating with an evaporation can so as to subject a low- temperature waste heat and raw water in the evaporation can to heat exchange and generate water vapour in the evaporation can ; a. condenser cooperates with a raw water tank so as to receive me water vapour from the evaporation can, cool the water vapour by subjecting the watef vapour and mw water in the raw

water tank to heat exchange and obtain distilled water; a distilled water tank for storing the distilled water; vacuum means for evacuating the evaporation can and depressurizing the inside thereof so as to promote generation of water vapour in the evaporation can ; and raw water supply means for supplying raw water to the evaporation can.

United States Patent 6,132,613 discloses a Cent al reversoostnosis desalination unit incorporating an annular membrane cartridge This invention relates to an apparatus for separating an original feed solution such as seawater into a product soluton of decreased concentration (relatively fresh water) and an exhaust solution of increased concentration. The apparatus includes an annular reverse osmosis membrane means, contained in an annular pressure vessel that is housed in a rotor assembly. The rotor is arranged to spin on an axle and is located within an evacuated shroud. The apparatus further includes supply means for supplying the original feed solution to the reverse osmosis membrane, exhaust means at an outermost radius of the reverse osmosis membrane for removing the exhaust solution from the reverse osmosis membrane, product removal means at an innermost radius of the reverse osmosis membrane jbr removing the product sohnjon from the revatse osmosis membrane and means for creating a pressure differential across the reverse osmosis membrane to separate the original feed solution into the product solution and the exhaust solution. The supply means and the exhaust means are relatively ax. ially antl radially spaced such that the feed solution travels along a combined radial and axialflow-path.

It may be seen from the above examples of the prior art methods and apparatuses for desalination, that many employ complex structures which are expensive to construct run and maintain, Also the known apparatuses employ mowing parts such as single and contra spinning rotors which due to high maintenance contribute to overall inefficiency of the known systems.

INVENTION The present invention seeks to overcome the problems of the prior art apparatuses and methods for fluids sepamtion and particularly though not limited to desalination by providing a process and associated apparatus which provides efficient and cost effective desalination. and with no moving parts.

Tb ! s invention provides an apparatus and method for separating immiscible liquids or solids from liquids by the application of a centrifugal force to the liquid using a centrifugal separation force generated by introducing a high velocity fluid feed stream. into a separation unii including a spiral passage having decreasing cross-section for producing a continuously increasing velocity as the feed st-eam proceeds along the passage.

Although the invention will primarily be described with reference to it$ application to desalmation, it will be recognised that desalination is but one exampLe of the application of the system and apparatus of the invention to be described herein. For instance the apparatus may be used in the separation of viscous liquids from. non or less viscous.

Throughout this specification, reference to a feed solution should be taken as a reference to a contaminated solution. from which is to be separated contarninants such as but not limited to sodium chloride. A reference to product is a reference to a solution having reduced contaminants or all contaminants removed. A reference to exhaust is a reference to a solution havmg contaminants which is discharged from the desalinator.

To overcome the restraints created by the processes mentioned above a new approach is needed, which is embodied in the description of the process and apparatus relating to the desalination of feed water for which the following are the objectives.

It is one objective of the present invention to provide a process for separating a mixture of a less dense liquid and a more dense liquid component by the application of centr@fugal force inside a stationary apparatus by introducing a high velocity fluid stream into a horizontal Archimedian spiral like cavity having a decreasing cross-section thus generatmg a continuously increasing velocity., It is stilt a further object of the present invention to apply the aforesaid arrangement for desalination of seawater, bore water and brackish water to imgation water pufily containiog no more than 600 to 800ppm dissolved solids.

It is another objects of the present invention to provide a process and apparatus which will yield Id potable water for human consumption and which contains no more than 300 parts per million of dissolved solids.

It is yet another object of the present invention to provide a process and apparatus capable of supplying hgh purity industrial water.

Finally, it is another object of the present invention to provide a pmctical application of the Archimedian Desalinator, which will reduce if not eliminate the continuous maintenance needed to support an economic desalination open3tio is another object to provide a system and appamtus for desalination and to reduce the initial investment cost and provide a clean, etivironmemany friendly, cheap, dependable desalination operation. <BR> <BR> <BR> <P>According to one aspect of the invention there is provided an apparatus fbf separating an original feed solution into a product solution of decreased contaminant concentration and an exhaust solution of increased concentration.

In its broadest form the present invention comprises :

an apparatus for separating a feed solution into a product solution. of decreased concentration and a. n exhaust waste solution of increased concentration, the apparatus comprising (a) a supply source of feed solution of water having contaminants for separation b) a supply line for ceding said feed solution from the supply source to said apparatus, c) rneans for driving said supply source into said apparatus under pressure ; d) at least one inlet line for delivery under pressure of said feed solution to at least one feed solution separator ; wherein. said feed solution is passed at a predetermined velocity through a stationary spiral formed in said at least one fed solution separator, sufRcient to generate a centrifugal force on said feed solution which induces separation of the feed solution into said product solution of decreased concentration and exhaust waste solution of increased concentration.

In another broad form the present invention comprises : An apparatus for separating a feed solution into a product solution of decreased concentration and an exhaust waste solution of increased concentration, the apparatus comprising: (a) a source of feed solution of water having contaminants for separation, b) a supply line for feeding said feed solution from a supply source to said apparatus ; c), a pressure vessel d) at least one inlet line for delivery of said feed solution to the pressure vessel under pressure ;

e) a desalinatr retained on the pressure vessel and including a ba$e, a cover and sealing means, f) support means for supporting said pressure vessel ; wherein said feed solution is passed through the desalinator via said pressure vessel with sufficient velocity to generate a centrifuga force on said solution which induces sepamtton of the feW solution into said product solution of decreased concentration and exhaust waste solution of increased concentration.

Preferably the desalinator includes a bore which. receives and rein$ therein said pressure vessel. The desalinator further comprises a genefatly annntar shaped main body and an internal horizontal spiral passage of gradually increasing radial extent which receives the feed solution. Preferably the spiral passage has a decreasing cross section along its tength from the at least one inlet. Preferably, ., ross section of the spiral passage produces a continuously increasing velocity of said feed solution as it travels along the spiral passage.

According to one cmbodintent the main body of the desalinator has a stepped centre core to which a plurality of ribs are attached. The bore of the desalinator enables said pressure vessel and said desalinator to meet in slidable engagement anywhere along the length of the pressure vessel. According to a preferred embodiment, a working pressure of said pressure vessel is around half the design pressure of said pressure vessel.

The base ofthe desalinator has sufficient depth to provide said spiral passage as an Archimedian spiral wherein the spiral is represented in polar co ordinates by the form. ula r = ai. The desalinator includes an exhaust port for discharging waste material separated from the feed. solution. The desalinator al$o inctudes an exhaust port for. discharge of feed solution with waste material removed.

Preferably, the exhaust port for the waste material is oriented at a tangent to a circumference deemed by one spi. ral of the spiral passage of the desalinator.

According to a preferred embodiment the exhaust port for the discharge of the

feed solution with waste removed is disposed at an outermost r. ardial extent of the spiral passage. The support assembly includes support plates and the feed solution travels along a combined spiral and radial flow-path.

In a further broad ibrm the present invention cornpnses : a separator for use in a separating apparatus for separating a feed solution into a product solution of decreased concentration and an exhaust waste solution of increased concentration, the apparatus comprising: (a) a source of feed solution of water having contaminant for separation, b) a supply line for feeding said feed solution fro ! n a supply source to said apparatus ; c). a pressure vessel d) at least one inlet line for delivery of sa. feed solution to the pressure vessel under pressure ; the separator being retained on the pressure vessel and including : a base, a cover and sewing means ; a bore which receives and fstaitts therein said pressure vessel ; the separator further comprising ; a genel. Uy annuat shaped main body-, and having an internal horizontally disposed spiral passage of gradually increasing radial extent which receives said feed solution ; wherein said feed solution is passed through the separator via said pressure vessel w. ith sufEcient velocity to generate a centrifugal force on said solution which induces separation of the feed solution into said product solution of <BR> <BR> decreased sed concentration and exhaust waste solution of increased concentration.

In another broad fonn of a method aspect, the present invention comprises : a method for desalination of salt water using an apparatus for. separating a feed solution into a product solution of decreased concentration and an exhaust waste solution of increased concemiadon, the apparatus comprising : (a) a supply source of feed solution of water having contarninants for separation, b) a supply line for feeding said feed solution from the supply source to said Apparatus ; c) means for driving said supply source into said apparatus under pressure; d) at least one inlet line for delivery under pressure of said feed solution to at least one feed solution separator ; the method comprising the steps of : a) passing the feed solution at a predetermined velocity through a stationary spiral formed in said at least one feed solution separator b) allowing the feed solution to travel through the spiral generating a centrifugal force sufficient to induce a separation in the feed solution ; c) causing the product solution of decreased concentration to exit the spiral via an oudet ; d) causing the exhaust waste solution of increased concentration to exit the $p via another outlet.

According to a preferred embodiment the method comprises the further step of ; providing a slit upstream of said outlets and adjusting the slit to ensure to allow separate discharge &om the spinal of the product solution of decreased concentration and the exhaust waste solution of increased concentration.

The slit may be adjusted to allow separate discharge from the spital of the product solution of decreased concentration and the exhaust waste solution of increased concentration irrespective of the velocity of the feed solution through said spiral.

BRIEF DESCRIPTION OF THE DRAWINGS.

The present invention witl be described in rnore detaal with. reference to a preferred but non imputing embodiment and with reference to the accompanying illusttattons, Attention is now directed to Figures I to 4, which display various matures characterising a preferred embodiment of the invention; wherein; Figure 1 shows an elevation view of an apparatus for desalination according to a preferred : miment Figure 2 shows a top plan view of the apparatus of figure 1 ; Figure 3 shows an exposed view of the Archimedian spiral slit and seal arrangement according to a preferred embodiment ; and Figure 4 shows a schematic layout of a desalination assembly according to a preferred embodiment.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring to figure 1 there is shown an elevation. view of an apparatus t for use in a desalination assembly according to a preferred embodiment. Apparatus 1 comprises a pressure vessel 2 having a C ; nst end 3 and second end 4. Second end.

4 terminate in a support assembly 5 which comprises a prefabricated cylindrical support 6 retained by base plate 7 which is preferably fastened to a ground surface or platform 8 via fastener 9 which engages jock washer 10. It

will be appreciated by persons skilled in the art that mul. tiple fasteners 9 may be used according to load resisting requirements on apparatus 1 Preferably fasteners 9 are bolts. Support assembly 5 includes reinforcing flanges 11 and 12 which am attached t ; o base plats 7 which is preferably circular and to which is attached the flanges 11 and 12. Flanges 11 and 12 are preferably tapered inwards from the base plate 7 and upwardly and provide stability to apparatus 1.

Assembly 5 includes a cylindrical location sleeve 13 which receives and retains therein pressure vessel 2. Tapered flanges 11 and 12 are attached to and retain location sleeve 13 which is preferably a headed bush like component having a circular flat upper suxFace thus prosding a suitable location for pressure vessel 2 and separation/desalination unit 14. The support assembly 5 may be made from mild steel provided that it is protected against corrosion.

The cylindrical location sleeve 13 also provides means of support for pressure vessel 2 which will preferably be cylindrical. Cylindrical pressure vessel 2 includes tonsphericat end caps 15 and 16 and is manufactured in accordance with prescribed pressure vessel standards. Pressure vessel 2 will contain the highly pressurised feed solution (such as seawater, bore water or brackish water) so the design pressure of vessel 2 should be about twice the working pressure needed to accomplish the required maximum (increasing) velocity of the feed solution.. The vessel 2 is continuously pressurised and the internal design of the vessel xs such that it reduces, if not eliminates, turbulence of feed water during the continuous operation.

The pressure vessel 2 comprises a feed water inlet assembly 20 comprising inlet pipe 21 and attachment locking connector 22. Locking connector 22 is prefvably a stainless steel HY-Lok male connector located in the centre of the pressure vessel 2 which will ensure an outstanding lack-tight connection for the stainless s steel feed water inlet pipe 21. Adjacent to the feed water inlet assembly 20 is a HY-ro high pressure relief valve 23 preferably having a cmcking

pressure within the range of 10-5150 kPa. The valve 23 material is preferably stainless steel with a Viton seat The e relief valve 23 is preset to the maximum allowable pressure and upon reaching me said pressure it will bleed to atmosphere via a bleed pipe 24 which ich is preferably stainless steel. The HY- Pro relief valve 23 is the preferred vatve, however, any suitable valve which can withstand the harsh pressures and environment may be used.

Pressure vessel 2 further comprises an output line or feed pipe 2S which preferably engages and co operates with a stainless steel HY-Lok male connector 26. To maintain near uniform back- pressure the feed pipe output 25 must be marginally smaller than the feed water input line 21. Pressure vessel 2 also includes a stainless steel drain plug 27.

As mentioned before the pressure vessel is manufactured according to a prescribed Standard, with the preferred material of construction stainless steel 316. However, any suitable material may be used provided it is capable of withstanding fhe erosion caused by the feed water (seawater, bore water or brackish water).

Referring to figure 2 there is shown a top view of the apparatus of fire 1 wiffi corresponding numbering. The pressure vessel 2 comprises a feed water inlet assembly 20 comprising inlet pipe 2) and attachment locking connector 22.

Locking connector 22 is preferably a stainless steel HY-Lok male connector located in the centre of the pressure vessel Z which will ensure an outstanding lock-tight connection fot the stainless steel feed water inlet pipe 21. Adjacent to the fed water inlet assembly 20 is HY-Pro high pressure relief valve item 23 As indicated, the valve 23 material is preferably stainless steel with a Viton seaL The relief valve 23 is preset to the maximum allowable pressmt : and upon reaching the said pressure it wilt bleed to atmosphere via bleed pipe 24 which is preferably stainless steel. The HY-Pro relief valve 23 is the preferred valve, however, any suitable valve which can withstand the harsh pressures and environment may be used.

Output line 25 preferably consists of a stainless steel HY-Lok male connector 26.

Referring to figure 3 there is shown designation unit 14 which includes an Archimedian spiral 28 and is typified by having no moving parts. The desalination unit 14 emprises three main components, namely desalinator base 29, desalinator cap hem 30 and the seal 31 (see figure 1).

The desalinator base 29 consists of a hollow disc shaped main body 33 having a stepped bush like centre core 34 to which a number of ribs 35 are joined, thus supporting and strengthening the base 29. The bore 37 of the centre core 34 of desalination unit 14 allows a slide fit with the pressure vessel item 2 thus providing a suitable vertical location for the Archimedian spiral desalination assembly which is held relatively solid by a number of socket set screws 32.

The smooth upper surface of the disc shaped body 33 must be perpendicular to the protruding part of the centre core which is partially threaded to match lock nut 3S (sec figure 1). The disc has sufficient depth to embody the Architnedian spiral li. ke cavity 36 which is a special spiral, represented in polar co-otdinates by. r = a 0. The spiral. may be described as the locus of a point moving with uniform velocity along the radius vector, while the mdius vector also moves about vith constant angular velocity. The evolute of this spiral approaches asymptotically to a circle with radius a. Accordingly, if sufficient back pressure is nintained to develop the high velocity needed to force the feed water along a highly pol. ished rchimedian spiral like cavi. ty 36 with a continuously increasing velocity the centrifugal force will manifest itself. It is known that because of the polarity of solid salt, water can easily dissolve iL For example, when an NaCl (Sodium chloride) salt, is dissolved into water, it is separated into its component ions, Na+ and Cl- because of the water polarity.

These ions move away from the salt crystal and fit into the gaps of the H2O chains. Therefore, the contaminated H2O chains density will increase, thus separation by centrifugal force will become feasible. In brief, the Archimedian

spiral desalination atisembly will act as a centrifuge, and apparatus which uses the centrifugal effect to separate solids from liquids, liquids from other liquids.

Thus it is capable of desalinating sea water, bore or brackish water as stated above.

In the-construction of tho spiral cavity the pitch minus the breadth of spiral cavity 36 will'leave a solid separation wall having sufficient Aidth to embody a spiral like groove 39 which contains the separation seal 31 (see Figure 1). The separated spiral cavity 36 begins close to the centre core 34 as shown by fi 3 and progressing in the direction of the arrow 40 spirally and radially to an outermost cavity 36* where an adjustable slit 41 is constructed which will induce the separation. of. the potable water from the brine. The position of the slit 41 relative to the cross section of the cavity 36 controls the purity of the potable water. The purity is maintained by the continuously decreasing cross-section of the spiral cavity which maintains the increasing velocity, The velocity of the Jluid stream Rowing in cavity 36 to. mass w b ie leading (upstream) edge of slit 41. At leading edge 41a of slit 41 a separation occurs between the product and exhaust waste. The exhaust is urged by centrifugal force against a radially outermost wall 36b of cavity 36 creating an <BR> <BR> <BR> essentially veftical division between the product and the waste. When the separation occurs tho pressure locally deceases ad the separated exhaust brine will exit the desalinator 14 device via an exhaust port 43. The bulk of the feed water introduced into the desalinator 14 which is potable following the separation, will depart the device through an outlet 42. The brine exhaust port 43 is connected to @ stainless steel pipe 44 preferably via a 14Y-Lok male connector item 45 (see Figure 2). Figure 2 also exhibits the potable water outlet 42 which terminates in a suitable stainless steel outlet pipe 46 which consists of an HY-Lok male connector 47.

To maintain a leak tight separation between Hie cavities 36 to 36a fonned by the Archimedian spiral, a suitable sealing element such as but not limited to a Nitrile cord is employed to form seal 31 disposed in spiral gtoove 39 which may be vulcanisez or cold joined with Cyanoacrylate. The pressure needed to compress the seal 3 : t is derived by the desalinator cap 30 which is fastened in position by use of a number of drilled and tapped holes 49 as shown by Figure 3 and suitable bolts So which are secured Mock nuts 51.

The construction of the desalinator cap 30 comprises a hollow disc shaped main body 52 having a bush like centre core 53 to which a number of ribs 54 are joined and extend radially (see Figure 1). The bore 37 of the centre core 34 is slidably fitted on the stepped bush centre core of the base 29 of desalinator 14, The smooth surface of the cap 30 is perpendicular to the bore of the centre core and provides a close fit to desalinator base 29, A number of equally spaced holes located opposite the drilled and tapped holes as well as the lock nut 38 will maintain the pressure and the position of base 29 relative to cap 30 and desalinator 14 relative to pressure vessel 2. The feed water outlet 25 from pressure vessel 2 provides an inlet to desalinator 14 through the disc shaped main body cover 30 directly opposite to the beginning of the Archimedian spiral cavity 36 in base 29 and connected via. a stainless steel HY-Lok male connector 55 (see figure 2). Feed water travels in outlet pipe 25 in the direction of arrow 56.

The preferred material for the desalinator base 29 and the desalinator cap 30 is stainless steel 31 6, however, any suitable material including industrial ceramic may be used provided it is capable of withstanding the potential erosion caused by the various feed waters which may pass through the assembly 1.

The desalinator base 29 and cap 30 respectively will preferably rest on support assembly 5 which includes an Ertalyte buffer which is placed in between the support assembly 5 and the desalinator base 29.

Figure 4 shows a schematic layout of a system including destination assembly 1 incorporated into a desalination unit ac ding 1 a preferred embodiment.

The construction n of the Archimedian Desalinator assembly 1 has been previously described so it. remains to describe how the assembly 1 may be incorporated into a desalination system according to one non limiting embodiment. Figure 4 shows a system from start to jHmsh in which potable water is produced from a feed water supply. The schematic diagram of the desalination process must be read as an example and it is to be understood that various alterations, niodifications andltor additions may be incorporated into the construction and arrangements of parts without departing from the spirit or scope of the invention. A ed water supply indicated by arrow 60 i$ introduced into manually operated stainless steel gate valve 61 located in feed line 62. A low pressure feed water 60 is screened to protect a vertical multistage cent al pump item 63. Pump 63 is an energy efficient high performance multi-stage pump activated by a control computer 64 via the controller 65.

The pump 63 preferably will operate with constant flow and pressure. However, the pressure requirements of the desalinator assembly 1 will vary depending on the salinity concentration of the feed water 60 which is coutinuously monitored by a salinity transducer 66. The minimum pressure needed to desalinate the feed water 60 is Mxed. Where the salinity of me feed water increases, the controt computer 64 wiU via the controller 65 energise an actuator 67 incorporating an integral bonnet needle valve G8.

The motorised aktuator 67 provides an external closed feedback control and compensates for variation in flow and pressure. The control computer 64 is pre" programmed to a required feed pressure to match the feed water salinity. Upon reaching the preset pressure level, a pressure transducer 69 will transmit a signal to comput G4, which in turn will stop and maintain the actuator 67 in the required position for feedback control. If the salinity of the feed water changes, the control computer will automatically reset the pressure.

Furthermore, the control computer 64 is progtammed to monitor the highest permissible salinity level of the potable water which is checked by a salinity

transducer 70. If the salinity level is higher than prescribed, the control computer 64 will render the system inoperative until the operating parameters are recalibrated. The system further comprises an electromagnetic ftowmeter Tt ensuring continuous accuracy and providing a means to record output of the Archimedian Desalinator assembly t.

The cent al force exerted by the rotating mass and the increasing velocity of the feed water, is derived by the feed pressure used in the process-The outward force on the particles Mating about the axis, which by Newton's Third Law is equal and opposite and as such has a magnitude equal to and a direction opposite to the centripetal force. Therefore, the reaction force exerted by the centrifugal force, which is Mw2R in a direction away from the centre of rotation is capable of separating heavy particles, a more dense liquid and a less dense liquid components by a carefully constructed adjustable slit 41 located tangential to an outmost diameter on the Archimedian spiral cavity 36a.

By the application of the described process in a stationary apparatus feed water such as seawaterS bore water or brackish water can be desalinated to provide irrigation water with purity of 600 to BOOppm.

In order to highlight the practical application of the process and apparatus, attention should be directed to me simplicity of the Archimedian Desalinator construction. As stated previously the apparatus contains no moving parts thus continuous maintenance is eliminated and an economic opemtion is assured.

To highlight ns economy the following example is provided, tf the electrical input of the Desalinator is 15kw its output is 400.000 litres per day which may be increased or decreased at will.

The assembly may according to one embodiment, be set up as a multiple tiered apparatus in which, there are multiple separation or desalination stations in series

or parallel and which allow$ tteatment of one or multiple supply streams concurrently or selectively irkdividualty, While the invention has been described concerning specie c embodiments thereof and in a specific use, various modifications thereof will occur to those skilled in the art without departing from the spirit and scope of the invention as set forth herein. The terms and expressions employed in the specification are used as terms of description and not of limitations, and are not intended to exclude any equivalen1s of the features showa and described or portions thereof Nevertheless, it is recognized that various modifications are possible within the scope of the claims to the invention.