Reverse-osmosis apparatus for producing fresh water from seawater

• US 4,452,696 A
• Filed: 04/06/1982
• Issued: 06/05/1984
• Est. Priority Date: 04/06/1981
• Status: Expired due to Term

• Current Assignee: Fernand Lopez
• Original Assignee: Fernand Lopez
• Inventors: Lopez, Fernand
• Primary Examiner(s): Spear, Jr., Frank A.
• Application Number:
  US06/365,898
• Time in Patent Office: 791 Days
• Field of Search: 210/416.1, 210/321.1, 210/433.2, 210/242.1, 210/170
• US Class Current: 210/170.11
• CPC Class Codes: B01D 2311/14 Pressure control
• CPC Class Codes: B01D 2313/06 External membrane module supporting or fixing means
• CPC Class Codes: B01D 2313/18 Specific valves
• CPC Class Codes: B01D 2313/20 Specific housing
• CPC Class Codes: B01D 2313/2011 Pressure vessels
• CPC Class Codes: B01D 2313/24 Specific pressurizing or depressurizing means
• CPC Class Codes: B01D 2315/06 Submerged-type; Immersion type
• CPC Class Codes: B01D 61/08 Apparatus therefor
• CPC Class Codes: B01D 63/024 with a single potted end
• CPC Class Codes: B01D 63/0241 being U-shaped
• CPC Class Codes: C02F 1/002 using small portable filters for producing potable water, e.g. personal travel or emergency equipment, survival kits, combat gear C02F1/003 takes precedence
• CPC Class Codes: C02F 1/441 by reverse osmosis
• CPC Class Codes: C02F 2103/08 Seawater, e.g. for desalination
• CPC Class Codes: Y02A 20/131 Reverse-osmosis

Abstract

The invention concerns a fresh-water producing apparatus to be immersed in a marine medium and of the type comprising at least one reverse-osmosis selective semi-permeable membrane.

This apparatus comprises three stages: a fresh-water stage consisting of collecting means for the produced chamber provided with a semi-permeable membrane placed between this chamber and the fresh-water collecting means; and, a third stage comprising a mobile piston and an hermetic chamber having a gaseous atmosphere. The piston is designed to enter in variable depth the high-pressure chamber by one side having an effective area s and comprising an opposite side with an effective area S exceeding the area s and arranged to be at the pressure of the marine medium.

Claims

1. A reverse-osmosis fresh water from seawater system adapted for being submersed in a marine medium, comprising:

(a) fresh-water collecting means;

(b) a high-pressure chamber adapted for containing seawater therein;

(c) an hermetic chamber;

(d) a semi-permeable membrane positioned in said high-pressure chamber and adapted for reverse-osmosis separation of fresh water from seawater and having a fresh water side in fluid communication with fresh water collecting means and a salt water side immersible in salt water containable in said high-pressure chamber;

(e) pressure application means associated with said hermetic chamber and in pressure communication with said high-pressure chamber for applying pressure to seawater containable therein whereby fresh water flows through said semi-permeable membrane to said fresh water collecting means thereby; and

(f) valve means in fluid communication with said marine medium and said high pressure chamber for filling said high-pressure chamber with seawater.

2. A system as defined in claim 1, further comprising:

(a) fresh-water withdraw means associated with said fresh-water collecting means for withdrawing collected fresh water.

3. A system as defined in claim 2, further comprising:

(a) said fresh-water collecting means including a collecting tank detachably sealed to said high-pressure chamber;

(b) support means secured to said collecting tank and disposed between said collecting tank and said high-pressure chamber and having fresh water distribution means therethrough in fluid communication with said semi-permeable membrane and said fresh-water collecting tank; and

,

(c) said semi-permeable membrane secured to said support means and extending into said high-pressure chamber when said collecting tank is sealed to said high-pressure chamber.

4. A system as defined in claim 3, wherein:

(a) said support means including a threaded lid;

(b) said collecting tank having interior threads in threaded engagement with said lid threads;

(c) a membrane support secured to said lid opposite said fresh-water collecting tank for supporting said semi-permeable membrane; and

,

(d) a plurality of apertures aligned with said semi-permeable membrane and traversing said membrane support and said lid.

5. A system as defined in claim 3, wherein:

(a) a snap-in system detachably sealing said collecting tank to said high-pressure chamber.

6. A system as defined in claim 1, further comprising:

(a) said fresh-water collecting means including a collecting chamber; and

,

(b) a flexible conduit extending from and sealed to said collecting chamber for withdrawing collected fresh water.

7. A system as defined in claim 6, further comprising:

(a) said system having a hydrodynamic profile adapted for towing by a boat;

(b) cable means secured to said boat and said system; and

,

(c) said flexible conduit secured to said cable means.

8. A system as defined in claim 7, further comprising:

(a) at least one external orientable flap associated with said hermetic chamber and adapted for raising and lowering said system as said system is towed by said boat; and

,

(b) control means cooperating with said piston for controlling said at least one flap.

9. A system as defined in claim 6, wherein:

(a) said collected fresh water being under pressure for forcing said collected fresh water through said flexible conduit.

10. A system as defined in claim 1, wherein:

(a) said semi-permeable membrane including a plurality of loop shaped hollow capillary fibers.

11. A system as defined in claim 1, further comprising:

(a) said hermetic chamber having a gaseous medium sealed therein;

(b) a hollow cylinder secured to said high pressure chamber and having a portion extending into said hermetic chamber;

(c) a pressure displaceable reciprocal piston positioned in said hermetic chamber co-axial with said cylinder and having a first portion displaceable through said cylinder; and

,

(d) said piston being displaceable from a first low-pressure position to a second high-pressure position associated with said piston first portion being displaced into said cylinder for applying pressure to said high-pressure chamber when said system is emerged in said marine medium to a pre-selected depth.

12. A system as defined in claim 1, further comprising:

(a) return means cooperating with said piston for displacing said piston to said first low-pressure position when said system is at a pre-selected depth in said marine medium.

13. A system as defined in claim 12, wherein:

(a) said return means including a coil spring coaxially mounted about said piston.

14. A system as defined in claim 11, wherein:

(a) said fresh-water collecting means, said high-pressure chamber, and said hermetic chamber being coaxial.

15. A system as defined in claim 14, further comprising:

(a) an envelope surrounding said semi-permeable membrane and having a plurality of apertures therethrough.

16. A system as defined in claim 15, wherein:

(a) said valve means being coaxial with said pressure application means.

17. A system as defined in claim 16, further comprising:

(a) said valve means including a displaceable control member cooperating with said pressure application means;

(b) a first rod connected to said control member and displaceable therewith;

(c) first and second valve means secured to said first rod and adapted for being opened and closed by said pressure application means as said piston is reciprocally displaced.

18. A system as defined in claim 16, wherein:

(a) said fresh-water collecting means, said high-pressure chamber, and said hermetic chamber being generally cylindrically shaped.

19. A system as defined in claim 15, wherein:

(a) said collecting tank having a volume of between 0.5 and 2.0 liters.

20. A system as defined in claim 14, further comprising:

(a) cable hookup means associated with said collecting tank for raising and lowering said system into said marine medium.

21. A system as defined in claim 11, wherein:

(a) said piston first portion having a pre-selected area; and

,

(b) said piston having a second portion positioned in said hermetic chamber and a pre-selected area exceeding said first portion pre-selected area.

22. A system as defined in claim 21, further comprising:

(a) said piston second portion having a peripheral seal for maintaining said gaseous medium in said hermetic chamber.

23. A system as defined in claim 22, wherein:

(a) said hermetic chamber being generally cylindrical and adapted for guiding said piston second portion therein.

24. A system as defined in claim 21, wherein:

(a) said piston second portion area being between 15 to 40 times said piston first portion area.

25. A system as defined in claim 11, further comprising:

(a) said piston including a bell having a circular portion, a lateral cylindrical wall, and an axial extension;

(b) said hermetic chamber being generally cylindrical and adapted for receipt of said bell; and

,

(c) an hermetic flexible membrane disposed between said bell and said hermetic chamber for retaining said gaseous medium therein.

26. A system as defined in claim 25, further comprising:

(a) a platform associated with marine medium surface; and

,

(b) a rise and descent assembly secured to said platform and said system for raising and lowering said system.

27. A system as defined in claim 1, wherein:

(a) said valve means adapted for opening at a pre-selected depth associated with a pre-selected marine medium pressure whereby said high-pressure chamber pressure is less than said marine medium pressure.

28. A system as defined in claim 27, wherein:

(a) said valve means adapted for sweeping seawater into said high-pressure chamber for removing concentrated seawater from said high-pressure chamber.