Atmospheric Water Harvesters

• US 20090241580A1
• Filed: 03/25/2008
• Published: 10/01/2009
• Est. Priority Date: 03/25/2008
• Status: Active Grant

• Current Assignee: Water Generating Systems I, LLC
• Original Assignee: Water Generating Systems LLC
• Inventors: Hill, James W., Preston, Christopher G., Max, Michael D.
• Granted Patent: US 8,627,673 B2
• Time in Patent Office: Days
• US Class Current: 62/291
• CPC Class Codes: E03B 3/28 from humid air condensing of vapours in general B01D5/00; dehumidification of air for air-conditioning F24F3/14
• CPC Class Codes: F24F 11/77 by controlling the speed of ventilators
• CPC Class Codes: F24F 3/1405 in which the humidity of the air is exclusively affected by contact with the evaporator of a closed-circuit cooling system or heat pump circuit
• CPC Class Codes: Y02A 20/00 Water conservation; Efficient water supply; Efficient water use
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

An atmospheric water harvester includes a cooling member over which humid air flows to condense moisture from the atmosphere. The cooling member may be the evaporator of a conventional, gas vapor-based refrigeration circuit. If a gas vapor-based refrigeration circuit is used, the compressor of the circuit may be variable speed. A fan or impeller used to move air through the system may also be variable speed. A preferred embodiment includes a variable flow geometry thermal economizer section configured such that, to varying degrees, the incoming air may be pre-cooled, before it passes over the cooling member, by heat exchange with colder air that has already flowed over the cooling member.

Claims

1. An atmospheric water harvester (AWH), comprising:

a housing;

a cooling device disposed within the housing for condensing atmospheric moisture;

an airflow passageway extending through the housing from a first inlet, across the cooling device, to one or more outlets;

a heat exchanger having a first heat exchange portion disposed upstream of the cooling device and a second heat exchange portion disposed downstream of the cooling device, the heat exchanger being arranged to transfer heat from air traversing the first heat exchange portion to cooler air that has traversed the cooling device and that is traversing the second heat exchange portion, whereby air entering the airflow passageway through the first inlet can be pre-cooled before traversing the cooling device;

a second, bypass inlet arranged to introduce air into the airflow passageway at a location downstream of the heat exchanger'"'"'s first heat exchange portion, whereby air entering the airflow passageway through the second inlet is not pre-cooled; and

one or more fans or impellers arranged to propel air through the atmospheric water harvester;

wherein the atmospheric water harvester is configured to control the relative amounts of air entering the airflow passageway through the first and second inlets.

2. The AWH of claim 1, wherein the heat exchanger comprises an air-to-air heat exchanger;

the first heat exchange portion comprises a first set of heat transfer flow passageways; and

the second heat exchange portion comprises a second set of heat transfer flow passageways in thermal communication with the first set of heat transfer flow passageways.

3. The AWH of claim 1, wherein the relative sizes of the first and second inlets are variable so as to control the relative amounts of air entering the airflow passageway through the first and second inlets.

4. The AWH of claim 3, wherein the sizes of the first and second inlets directly and inversely co-vary, with the size of the first inlet being at a maximum when the size of the second inlet is at a minimum and vice-versa.

5. The AWH of claim 4, further comprising a sliding panel the position of which defines the relative sizes of the first and second inlets.

6. The AWH of claim 4, wherein the minimum size of each of the first and second inlets is totally closed.

7. The AWH of claim 3, wherein the sizes of the first and second inlets are independently variable.

8. The AWH of claim 1, wherein said one or more fans or impellers comprises a variable speed fan or impeller associated with each of the first and second inlets whereby the relative amounts of air entering the airflow passageway through the first and second inlets can be controlled by varying the speeds of the respectively associated fans or impellers.

9. The AWH of claim 1, wherein said one or more fans or impellers comprises a variable speed fan or impeller located at a downstream portion of said airflow passageway.

10. The AWH of claim 1, wherein the cooling device is metal and has a coating which prevents metal from dissolving into water condensing thereon.

11. The AWH of claim 1, wherein the cooling device has an antimicrobial coating thereon.

12. The AWH of claim 1, wherein the AWH comprises a vapor compression-based refrigeration system including a condenser, an evaporator, and a compressor and said cooling device comprises said evaporator.

13. The AWH of claim 12, wherein the compressor is a variable speed compressor.

14. The AWH of claim 1, further comprising a water collection region disposed below said cooling device for collecting water that has condensed on said cooling device and run off of said cooling device under the influence of gravity.

15. The AWH of claim 14, further comprising a pump disposed within said water collection region for transferring water from said water collection region to a user.

16. The AWH of claim 15, further comprising a water filter through which water transferred by said pump passes.

17. The AWH of claim 1, further comprising an air filter associated with each of said first and second inlets.