Component Arrangement For Gravitational Water Desalination

Abstract

High energy consumption and the negative impacts of hyper saline brine are the two biggest hurdles to a widespread adoption of seawater desalination. Taking advantage of the principal that fluid pressure increases in direct proportion to depth, this invention reduces energy consumption by relocating the process of reverse osmosis at depths where the weight of the water produces the pressure required to drive the reverse osmosis process thereby eliminating the high costs normally associated with raising intake pressure and by simply varying pumping rates, the brine stream can be pre-diluted to levels slightly above the original thereby reducing environmental impact. The simplicity of the design also reduces the costs of building and installation thereby making it likely that seawater desalination will proliferate around the world.

Claims

1. A component arrangement system comprising: (a) a vertically oriented bore and of substantial depth (b) a multiplicity of water pumps in fluid communication with water passages (c) a means to control the pumping rates of said pumps (d) at least one of said water passages adapted to evacuate water from a substantially deep point in said bore (e) at least one salt separation membrane assembly disposed at said depth and in fluid communication with at least one of said fluid passages whereby the weight of the water serves as the source of the pressure needed to accomplish reverse osmosis.

2. The arrangement of claim 1 incorporated into an underground chamber large enough to house a desalination plant.

3. The arrangement of claim 1 wherein said bore is a rigid tube disposed at sea to allow for offshore application.

4. The arrangement of claim 1 wherein the brine concentration is prediluted by varying the pumping rates of said pumps.

5. The arrangement of claim 3 wherein the bottom end of said bore is in fluid communication with seawater.

6. The arrangement of claim 3 wherein a multiplicity of said tubes is spaced out at sea.

Description

BRIEF DESCRIPTIONS OF DRAWINGS

[0017] FIG. 1 schematic of arrangement

[0018] FIG. 2 A more detailed view of arrangement without the pumps, interconnections and computer control module

[0019] FIG. 3A A more detailed view of the lower end of arrangement

[0020] FIG. 3B A variation of FIG. 3A where tube 2 has a opening 32

DETAILED DESCRIPTION

[0021] FIG. 1 shows an exemplary set up of arrangement. Vertical tube 2 is installed into the ground 6. Pump 12 supplies salt water from filter or reservoir (not shown) to Tube 2 through water line 10. From line 10 water goes through salt separation membrane assembly 4 and continues through water line 24 via Pump 18. The remaining brine is evacuated by pump 20 through waterline 22. Also shown in here is computer control module 16 in communication with water level sensor 8 and water pumps 12, 18 and 20 through wires 14. In order to reduce the salinity of the rejected water (if so desired), water line 22 may be pre-diluted prior to disposal by calibrating computer control 16 to run pumps 12 and 20 at a higher flow rate than pump 18.

[0022] FIG. 2 shows more detailed look of the arrangement (pumps, wires, sensor and computer not shown). Water line 10 with salt water 10’ connected ant the top of water tube 2 installed in ground. Water 10’ fills up tube 2 via gravity. The pressure of the water at the bottom of tube 2 forces the water through membrane assembly 4. Normally it takes around 70 bar (1,000 psi) to force water through membrane assembly 4. To generate that amount of water pressure using gravity, the membrane assembly 4 must be at depth 26 which is around 723 meters, therefore water tube 2 is longer than 723 m deep in order to collect rejected brine. The Salt free water 24' after membrane assembly 4 flows through water line 24 either for further treatment or ready for use. The rejected brine 22’ flows through water line 22 for disposal.

[0023] FIG. 3A is an even more detailed look at the bottom of the water tube 2. Salt water 10’comes in from the top and forced through membrane assembly 4 in direction 28. At that point salt-free water 24’ and continues through water line 24. The rejected brine 22’ collects at the very bottom of water tube 2 and sucked up by water line 22 as indicated by direction 30.

[0024] FIG. 3B is an offshore variation of FIG. 3A where the brine is disposed at the bottom of tune 2 in direction32 through opening 34.