Humidification-dehumidification systems and methods at low top brine temperatures

Patent metadata

Field	Value
Publication number	US-10294123-B2
Application number	US-201615161051-A
Country	US
Kind code	B2
Filing date	May 20, 2016
Priority date	May 20, 2016
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

Embodiments described generally relate to systems comprising a humidifier (e.g., a bubble column humidifier) and a heating device (e.g. a heat exchanger), and associated methods. In certain embodiments, the heating device heats a first liquid stream comprising a condensable fluid in liquid phase (e.g., water) and a dissolved salt (e.g., NaCl) to a relatively low temperature (e.g., about 90° C. or less) prior to the first liquid stream entering the humidifier through a main humidifier liquid inlet. In some cases, the system comprising the humidifier and the heating device requires only low-grade heat to operate, which may be advantageous due to the low cost and high availability of such heat.

First claim

What is claimed is:

1. A method of operating a humidifier, comprising:
flowing a first liquid stream comprising a condensable fluid in liquid phase and a dissolved salt through a first fluidic pathway of a first heating device, wherein the first liquid stream is heated within the first heating device to form a heated first liquid stream;
injecting the heated first liquid stream into a main liquid inlet of a humidifier comprising a plurality of stages, wherein the plurality of stages comprises a first stage, a last stage, and one or more intermediate stages positioned between the first stage and the last stage;
injecting a gas stream comprising a non-condensable gas into a main gas inlet of the humidifier;
flowing the heated first liquid stream through the humidifier in a first direction from the first stage to the last stage and simultaneously flowing the gas stream through the humidifier in a second direction from the last stage to the first stage, wherein heat and mass are transferred from the heated first liquid stream to the gas stream to produce a vapor-containing humidifier gas outlet stream and a concentrated liquid stream; and
flowing an extracted liquid stream comprising at least a portion of the concentrated liquid stream from an intermediate liquid outlet of the humidifier to the first heating device, wherein the intermediate liquid outlet of the humidifier is a liquid outlet of the first stage or one of the one or more intermediate stages of the humidifier;
wherein the method further comprises flowing the first liquid stream through a second heating device.

2. The method according to claim 1 , wherein the temperature of the heated first liquid stream at the main liquid inlet of the humidifier is about 90° C. or less.

3. The method according to claim 1 , wherein a flow rate of the extracted liquid stream at the intermediate liquid outlet of the humidifier is about 5% to about 50% of a flow rate of the concentrated liquid stream at a main liquid outlet of the humidifier.

4. The method according to claim 1 , wherein a flow rate of the extracted liquid stream at the intermediate liquid outlet of the humidifier is about 105% to about 150% of a flow rate of the concentrated liquid stream at a main liquid outlet of the humidifier.

5. The method according to claim 1 , wherein the humidifier is a bubble column humidifier.

6. The method according to claim 1 , wherein at least one stage of the plurality of stages of the humidifier comprises a bubble generator.

7. The method according to claim 6 , wherein the bubble generator comprises a sparger plate comprising a plurality of holes.

8. The method according to claim 1 , wherein at least one stage of the plurality of stages of the humidifier comprises a liquid layer comprising an amount of the heated first liquid stream and a vapor distribution region positioned adjacent the liquid layer.

9. The method according to claim 1 , further comprising flowing the vapor-containing humidifier gas outlet stream from a main gas outlet of the humidifier to a main gas inlet of a dehumidifier configured to remove at least a portion of the condensable fluid in vapor phase from the vapor-containing humidifier gas outlet stream to produce a dehumidifier liquid outlet stream and a dehumidifier gas outlet stream.

10. The method according to claim 9 , wherein the dehumidifier is a bubble column condenser.

11. The method according to claim 1 , wherein the first heating device is a first heat exchanger, a heat collection device, an electric heater, or a furnace.

12. The method according to claim 11 , further comprising flowing a heating fluid stream through a second fluidic pathway of the first heating device.

13. The method according to claim 1 , wherein:
the first heating device is a first heat exchanger,
the second heating device is a second heat exchanger, and
flowing the first liquid stream through the second heating device comprises flowing the first liquid stream through a first fluidic pathway of the second heat exchanger, and simultaneously flowing the dehumidifier liquid outlet stream through a second fluidic pathway of the second heat exchanger, such that heat is transferred from the dehumidifier liquid outlet stream to the first liquid stream to form a pre-heated first liquid stream.

14. The method according to claim 13 , further comprising flowing the pre-heated first liquid stream to the first heating device to form the heated first liquid stream.

15. The method according to claim 1 , further comprising flowing the heated first liquid stream to an intermediate humidifier liquid inlet, wherein the intermediate humidifier liquid inlet is a liquid inlet of the last stage or one of the one or more intermediate stages of the humidifier.

16. The method according to claim 1 , further comprising flowing the extracted liquid stream from the intermediate liquid outlet of the humidifier to a first tank prior to flowing the extracted liquid stream to the first heating device.

17. The method according to claim 1 , wherein the condensable fluid is water.

18. The method according to claim 1 , wherein the dissolved salt comprises NaCl.

19. A method of operating a humidifier, comprising:
flowing a first liquid stream comprising a condensable fluid in liquid phase and a dissolved salt through a first fluidic pathway of a first heating device, wherein the first liquid stream is heated within the first heating device to form a heated first liquid stream;
injecting the heated first liquid stream into a main liquid inlet of a humidifier comprising a plurality of stages, wherein the plurality of stages comprises a first stage, a last stage, and one or more intermediate stages positioned between the first stage and the last stage;
injecting a gas stream comprising a non-condensable gas into a main gas inlet of the humidifier;
flowing the heated first liquid stream through the humidifier in a first direction from the first stage to the last stage and simultaneously flowing the gas stream through the humidifier in a second direction from the last stage to the first stage, wherein heat and mass are transferred from the heated first liquid stream to the gas stream to produce a vapor-containing humidifier gas outlet stream and a concentrated liquid stream;
flowing an extracted liquid stream comprising at least a portion of the concentrated liquid stream from an intermediate liquid outlet of the humidifier to a first tank; and
after flowing the extracted liquid stream to the first tank, flowing the extracted liquid stream to the first heating device,
wherein the intermediate liquid outlet of the humidifier is a liquid outlet of the first stage or one of the one or more intermediate stages of the humidifier.

20. The method according to claim 19 , wherein the temperature of the heated first liquid stream at the main liquid inlet of the humidifier is about 90° C. or less.

Assignees

• Gradiant Corp

Inventors

• Lam Steven
• Wilson Conor Thomas
• St John Maximus G
• Govindan Prakash Narayan

Classifications

• B01D5/003

  within column(s) · CPC title

• B01D1/14

  with heated gases or vapours {or liquids} in contact with the liquid · CPC title

• C02F2103/08

  Seawater, e.g. for desalination · CPC title

• C02F2101/12

  Halogens or halogen-containing compounds · CPC title

• C02F1/048 Primary

  Purification of waste water by evaporation · CPC title