IL97062A

IL97062A - Installation for abtaining large quantities of sweet water by desalination of sea-water

Info

Publication number: IL97062A
Application number: IL9706291A
Authority: IL
Original assignee: Verbitski David
Priority date: 1991-01-27
Filing date: 1991-01-27
Publication date: 1994-11-28
Also published as: IL97062A0

Description

97062/2 AN INSTALLATIOH FOR OBTAINING LARGE QUANTITIES OF SWEET WATER BY DESALINATION OF SEA-WATER 97062/2 AN INSTALLATION FOR OBTAINING LARGE QUANTITIES OF SWEET WATER BY DESALINATION OF SEA-WATER The present invention relates to installations for desalination of sea-water and may be used for a low-lying area, e.g. for Israel where Dead Sea shore lies at the depth hOO m below sea level and not far from Mediterranian ^80 kmj and Red ^200! km) Sea, to produce sweet water for agriculture and industry^ with a reverse-osmosis method.

Some types of reverse-osmosis desalination installations . are known. One of them comprises a conduit with an inlet filter and reverse-osmosis membranes situated in the outlet end of the conduit,, A high pressure pump is installed in the conduit between said filter and membranes and pumps sea-water through the reverse-osmosis membranes. Aquated ions of dissolute salt are detained with the membranes. Sweet water molecules pass through the membranes. The described above installation suffers from the problems that it consumes a great deal of power to pump the sea-water through the membrane and it needs a large working area (building).

Other known reverse-osmosis desalination installation comprises a submerged reservoir which is suspended at a depth of ii70 m under sea level with floats, reverse-osmosis membranes which are fixed on the inlet openings of said reservoir and a submersible high pressure pump which is installed inside of said reservoir and pumps sweet water from the reservoir to a water tower situated at a sea shorec, (Israel's patent NO. 7I7IO of OI.05.8U). This installation doesn't need a large working area (building) because it 's submerged in a sea but it suffers from the problems that it consumes a great deal of power to pump the sweet water from the resevoir (the depth of k70 m under sea level) to the sea shore. Moreover there .;are problems to clean and change the membranes and to repair the pump situated under water at the depth h70 m.

It is an object of the present invention to overcome these problems and provides an installation for obtaining large quantities of sweet water by desalination of sea- water which may produce large quantities of sweet water and needs almost no power and working area for. sea-water desalinating.

According to the present invention an installation for obtaining large quantities of sweet water. by desalination of sea-water comprises a conduit with an inlet fil-- ter and a reverse-osmosis 'membrane situated in a conduit 's outlet end fixed on low-lying area of dry land at the depth 200·»1ι5θ m below sea level. An intermediate settler is installed in said conduit between said inlet filter and membrane and a top edge of the intermediate settler's side wall lies above sea level and the conduit's stretch situated between said inlet filter and intermediate settler is made as a siphon piping Embodiment of the present invention will now be described by way of example with reference to accompanying drawings in which: Figure I is the design of the proposed installation for desalination of sea-water; Figure 2 is an outlet end of said conduit with reverse-osmosis menbranes (detail;.

The installation for desalination of sea-water (Fig.I) comprises a conduit I with an inlet filter 2 (which may be made as a gravel filled an underwater concrete bunker 3 with a perforate partition h and be situated in a sea settler 5) and a reverse-osmosis membrane (membranes) 6 \ hich may be made e.g. from acetylcellulosa/polies- ter resin etc. and be fixed on a hollow solid body 7 (Fig.2) with holes 8 and tubes y for sweet water discharge to a reservoir 10) situated in a conduit's outlet end II fixed, on low-lying area of dry land at the depth 200*Ui>0 m below sea level(Fig.I ) .

An intermediate settler 12 is installed in said 'conduit I between said inlet filter 2 and membrane 6 and a top edge 13 of the intermediate settler's side wall I lies above sea level ("a"). 'conduit's stretch 15 situated between said inlet filter and intermediate settler is made as a siphon piping (with end 16 situated below sea level ("b").

A pump 25 is used to increase the speed of the ' water- along the"membrane 6 ' and- to · wash off a salt from the membrane. A valve 26 situated before membranes 6 is used to close the conduit I when the membranes 6 are replaced. A valve 27 situated after the membranes 6 is used for sireet water discharge adjusting. A pump 28 is used to pump the sweet water to consumers.

A salt concentrate may be discharged to fill Dead Sea and salt concentrate pressure may be used for electric power generation with a hydro urbine.

Due to intermediate settler installed between said inlet filter and membrane and a top edge of the intermediate settler 's side wall lies above sea level and the conduit 's stretch situated between said inlet filter and intermediate settler is made as a siphon piping the proposed installation become safe because sea-water won't inundate said low-lying area of dry land. The intermediate settler is also used for sea-water cleaning and makes it possible to pour sea-water from the conduit and to clean/repair the latter.

The installation works like this. The valves 18 and 20 are closed. The valves 17 and Iy are opened. The pump 21 is on and fills the siphon piping ^stretch 15) with sea-water from the bunker 3 Rafter the. perforate partition k of the filter 2). When sea-water is' poured out from the valve 17 then the latter is closed, the valve Iy is closed, the pump 21 is off and the valves l8 and 20 are opened. Sea-water flows by the siphon piping to the intermediate settler 12. Perforate partitions may be installe inside of the settler 12 for sea-water cleaning. A waterfall may be made in the settle 12 i,if the end of the stretch 15 is situated above the water surface in the settler 12) to clean sea-water by flotation process. Coarse sand and stones are deposited in the sea settler 5· The filter 2 detaines fine sand. The sea-water cleanliness' may be tested in the settler 12 before the stretch 22. Due to' the inlet of the stretch 22 is situated below water surface and above the bottom of the settler 12 a sand, seaweed and dirt don't flow to the membrane. Sea-wateir' flows by the stretch 22 of the conduit I to the membranes 6, path through the membranes under the pressure of the depth ( 00* U50 m) membranes are situated and is desalinated with the reverse-osmosis membranes 6.· The pump 2$ creates a circulation of sea-water along the membranes to clean the latters from salt. Salt concentrate is discharged by the drainage pipe 23.

Claims

1. CLAIM An installation for obtaining large quantities of sweet water by desalination of sea-water comprising a conduit with an inlet filter and a reverse-osmosis membrane( situated in a conduit's outlet end fixed on low-lying area of dry land at the depth 200+-if>0 m below sea level, an intermediate settler is installed in said conduit betwee said inlet filter and membrane and a top edge of the intermediate settler's side wall lies above sea level and the conduit's stretch situated between said inlet filter and intermediate settler is made as a siphon piping.