System and method to desalinate a feed water stream by mixing the feed water stream with a heating medium

Patent metadata

Field	Value
Publication number	US-10370264-B2
Application number	US-201615193771-A
Country	US
Kind code	B2
Filing date	Jun 27, 2016
Priority date	Jun 27, 2016
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

A system and method to desalinate a feed water stream does so in a liquid pool zone of a vessel as the stream comes into contact with a heating medium that is less volatile than the feed water stream. To keep the pool hot, the heating medium can be recirculated through a heater of a pump-around loop or a heater can be placed in the liquid pool. As the feed water stream is vaporized or partially vaporized, any solids and unvaporized water present in the feed water stream come out of the stream and move into the heating medium. These solids and unvaporized water may be further removed from the heating medium in the pool or in the pump-around loop. The heat exchange surface does not contact the feed water.

First claim

What is claimed is:

1. A method to desalinate a feed water stream, the method comprising:
routing the feed water stream into a liquid pool zone of a vessel, the liquid pool zone including a heating medium, the heating medium being less volatile than the feed water stream and maintained at an operating temperature determined by vaporization requirements;
routing a portion of the heating medium from the liquid pool zone of the vessel to a heater;
raising a temperature of the removed portion in the heater to produce a heated recycle stream;
routing the heated recycle stream back to the liquid pool zone;
vaporizing at least a portion of volatile components of the feed water stream due to contact with the heating medium in the liquid pool zone; and removing a vaporized portion of the feed water stream from a vapor separation zone of the vessel as steam;
compressing the steam;
condensing at least a portion of the steam; and
removing solids from the portion of the heating medium.

2. A method according to claim 1 further comprising pre-mixing the feed water stream and the heating medium outside of the liquid pool zone of the vessel.

3. A method according to claim 2 wherein during pre-mixing no vaporization of the volatile components of the feed water stream occurs.

4. A method according to claim 2 wherein during pre-mixing no more than about 90% of the volatile components of the feed water stream vaporize.

5. A method according to claim 1 further comprising separating and removing at least some of the solids from the vessel directly as blowdown.

6. A method according to claim 1 wherein the removed portion of the heating medium is a mixture of heating medium and at least some of the solids of the feed water stream.

7. A method according to claim 6 further comprising separating and removing at least some of the solids from the mixture prior to raising the temperature of the removed portion.

8. A method according to claim 1 wherein a density of the heating medium is greater than that of the feed water stream.

9. A method according to claim 1 wherein the heating medium is immiscible with the feed water stream.

10. A method according to claim 1 wherein there is no pre-treatment of the feed water stream prior to entering the liquid pool zone of the vessel.

11. A method according to claim 1 further comprising filtering the feed water stream by straining prior to the feed water stream entering the liquid pool zone of the vessel.

12. A method according to claim 1 further comprising recovering residual heat in the condensed steam.

13. A method according to claim 1 further comprising preheating the feed water stream.

14. The method of claim 1 , wherein the steam is condensed using the heater.

15. A system to desalinate a feed water stream, the system comprising:
a vessel arranged to contact the feed water stream and route the feed water stream into a liquid pool zone of the vessel, the liquid pool zone including a heating medium less volatile than the feed water stream and maintained at an operating temperature determined by vaporization requirements;
a pump-around loop arranged to route a portion of the heating medium residing in the liquid pool zone to a condenser to heat the portion to the operating temperature and return the portion back to the liquid pool zone; and
a compressor arranged to receive at least a portion of the steam exiting the vapor separation zone of the vessel and produce a pressurized steam,
wherein the condenser is arranged to receive at least a portion of the pressurized steam wherein when the feed water stream is contacted by the heating medium in the liquid pool zone at least a portion of volatile components of the feed water stream vaporize and migrate to a vapor separation zone of the vessel for removal and solids form in the liquid pool zone of the vessel for removal.

16. A system according to claim 15 further comprising a mixer located outside of the liquid pool zone of the vessel and arranged to mix the feed water stream and the portion of the heating medium being returned to the vessel.

17. A system according to claim 16 wherein the mixer is arranged so no vaporization of the volatile components of the feed water stream occurs in the mixer.

18. A system according to claim 16 wherein the mixer is arranged so no more than about 90% of the volatile components of the feed water stream vaporize in the mixer.

19. A system according to claim 15 wherein the vessel includes internals arranged to separate at least a portion of the solids from the heating medium.

20. A system according to claim 15 further comprising the pump-around loop including a separation device.

21. A system according to claim 15 further comprising a preheater to heat the feed water stream.

22. A method to desalinate a feed water stream, the method comprising:
routing the feed water stream into a liquid pool zone of a vessel, the liquid pool zone including a heating medium, the heating medium being less volatile than the feed water stream and maintained at an operating temperature determined by vaporization requirements;
routing a portion of the heating medium from the liquid pool zone of the vessel to a first heater;
routing the portion of the heating medium from the first heater to a second heater;
raising a temperature of the removed portion in the first and second heaters to produce a heated recycle stream;
routing the heated recycle stream back to the liquid pool zone;
vaporizing at least a portion of volatile components of the feed water stream due to contact with the heating medium in the liquid pool zone; and removing a vaporized portion of the feed water stream from a vapor separation zone of the vessel as steam;
compressing at least a portion of the steam;
condensing at least a portion of the steam; and
removing solids from the portion of the heating medium.

23. The method of claim 22 , wherein the condensing at least a portion of the steam is performed using the first heater.

Assignees

• Cameron Solutions Inc

Inventors

• Zheng Z Frank
• King Christopher Stephen
• Nemmara Harihara V

Classifications

• B01D1/0064

  Feeding of liquid into an evaporator · CPC title

• B01D1/2856

  The compressed vapour is used for heating a reboiler or a heat exchanger outside an evaporator · CPC title

• B01D1/0094

  with forced circulation · CPC title

• C02F2103/08

  Seawater, e.g. for desalination · CPC title

• B01D5/006

  with evaporation or distillation · CPC title