Composite desiccant and air-to-water system and method

• US 8,506,675 B2
• Filed: 03/28/2011
• Issued: 08/13/2013
• Est. Priority Date: 03/26/2010
• Status: Expired due to Fees

• Current Assignee: Joseph Ellsworth
• Original Assignee: Joseph Ellsworth
• Inventors: Ellsworth, Joseph
• Primary Examiner(s): LAWRENCE JR, FRANK M
• Application Number:
  US13/073,971
• Publication Number:
  US 20110232485A1
• Time in Patent Office: 869 Days
• Field of Search: 95/10, 95/11, 95/14, 95/52, 95/91, 951/23, 96/4, 961/09, 961/11, 961/12, 961/18
• US Class Current: 95/10
• CPC Class Codes: B01D 2253/10 Inorganic adsorbents
• CPC Class Codes: B01D 2259/40009 using sensors or gas analysers
• CPC Class Codes: B01D 2259/4009 using hot gas
• CPC Class Codes: B01D 2311/06 Specific process operations in the permeate stream
• CPC Class Codes: B01D 2311/106 Cooling
• CPC Class Codes: B01D 2311/13 Use of sweep gas
• CPC Class Codes: B01D 53/261 by adsorption
• CPC Class Codes: B01D 53/263 by absorption
• CPC Class Codes: B01D 53/28 Selection of materials for use as drying agents
• CPC Class Codes: B32B 2262/0223 Vinyl resin fibres
• CPC Class Codes: B32B 2266/0221 Vinyl resin
• CPC Class Codes: B32B 2307/728 Hydrophilic
• CPC Class Codes: B32B 2307/732 Dimensional properties
• CPC Class Codes: B32B 3/26 characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids foam layer B32B5/18; layer of synthetic resin characterised by fillers that create voids or cavities B32B27/205; characterised by an apertured layer
• CPC Class Codes: B32B 5/022 Non-woven fabric
• CPC Class Codes: B32B 5/18 characterised by features of a layer of foamed material
• CPC Class Codes: B32B 5/245 another layer next to it being a foam layer
• CPC Class Codes: B32B 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: B32B 5/32 at least two layers being foamed and next to each other

Abstract

A composite desiccant material is formed by a porous, absorbent substrate of PVA foam or non-woven fibrous sheet is soaked in a solution of a hygroscopic desiccant such as CaCl₂. The desiccant is held in pores or fibrous entraining areas sized ranging from 50 microns to 1000 microns. Thin sheets are arranged in a stack in a multi-chamber system, while in an absorption state, uses this stack in a main chamber to absorb H₂0 from atmospheric gas flowing through that chamber. In a regeneration state atmospheric flow is stopped and low-grade energy releases the H₂0 from the desiccant into that chamber. Fans circulate moist air through the main chamber and into an adjacent chamber for H₂0 transfer through or past a partially permeable barrier into a cooling/condensing area. Both H₂0 and dry gas may be produced.

Claims

1. A gas drying and water producing system comprising:

(a) a desiccant subsystem;

(b) a main chamber containing said subsystem and so configured as to provide at least one path for airflow from outside said main chamber, into said main chamber, through the desiccant subsystem and through an exit of said main chamber;

(c) a second, heating chamber, said heating chamber in fluid communication with said main chamber such that a heat-circulating path is selectively enableable between said chambers, said enableable path allowing a heat circulating flow through said heating chamber into said main chamber, through said desiccant subsystem and back to said heating chamber;

(d) the system further comprising a third condensing chamber selectively in gaseous communication with said main chamber;

said enableable path allowing a cooling circulating flow through said condensing chamber into said main chamber, through said desiccant subsystem and back to said condensing chamber;

(e) a control system configured to place the system into one of at least four states comprising;

quiescent, charging, condensing and regenerating, the control system configured to make state changes upon detecting an occurrence of one or more predetermined relationships between at least a modeled dew point within the desiccant subsystem, the temperature and humidity of the system'"'"'s ambient environment, the temperature of a heat source for the heating chamber, and of the temperature of a cold source for the condensing chamber.

2. The system of claim 1 further comprising a fourth, separating chamber selectively in gaseous communication with said main chamber, or optionally with said heating chamber;

said separating chamber having at least a portion of at least one of its enclosing walls comprised of one side of a planar semi-permeable element.

3. The system of claim 2 with said separating chamber being so configured as to provide for a sweeping flow substantially parallel to the semi-permeable element'"'"'s major plane and wherein the semi-permeable element forms at least a portion of an enclosing wall of a condensing chamber.

4. The system of claim 3 wherein said semi-permeable element substantially comprises a membrane that differentially allows passage of water vapor to a greater extent than it allows passage of molecules of nitrogen.

5. The system of claim 2 with said separating chamber being so configured as to provide for an air flow substantially normal to the semi-permeable element'"'"'s major plane and wherein the semi-permeable element forms at least a portion of an enclosing wall of a condensing chamber.

6. A system for producing water from air comprising:

a) a desiccant;

b) means for directing a flow of air through said desiccant such that a turbulent airflow results and moisture in the air is captured by the desiccant;

c) means for providing a first flow in a closed-loop path of heated air through the desiccant for extracting the moisture;

d) means for providing a second closed-loop flow causing moisture to condense into liquid water in a distinct third chamber;

e) means for controlling the system for efficient operation using external air moisture and temperature data and a modeled dew point of the desiccant.

7. A method of operating a gas drying, water producing, system comprising, in any operative order:

a) opening an intake port and an exhaust port for a desiccant chamber and forcing ambient air from the intake port through the desiccant chamber and out the exhaust port;

b) closing ports, and ceasing air forcing when a predetermined relationship exists between the ambient air moisture level and a modeled dew point of the desiccant;

c) opening at least two chamber-to-chamber ports coupling the desiccant chamber to a distinct condensing chamber and forcing air to recirculate around a path through the desiccant chamber, into the condensing chamber and back through the desiccant chamber while applying a relative cold source in the condensing chamber and producing and extracting liquid water, this step initiated upon detecting a predetermined relationship between the dew point and held moisture level of the desiccant chamber and the temperature of a relative heat source are favorable to efficient extraction of liquid water;

d) closing ports, and ceasing air forcing when a predetermined relationship exists between the temperature of the cold source and the temperature and modeled dew point of the desiccant;

e) opening at least two chamber-to-chamber ports coupling the desiccant chamber to a distinct regenerating chamber and forcing air to recirculate around a path through the desiccant chamber, into the recirculating chamber and back through the desiccant chamber while applying a relative heat source in the regenerating chamber;

f) closing ports, and ceasing air forcing when a predetermined relationship exists between the temperature of the heat source and the temperature and modeled dew point of the desiccant;

g) remaining in a quiescent state with ports closed and no air being forced until a predetermined relationship exists between the modeled dew point of the desiccant, the temperature of the ambient air, and the humidity of the ambient air that is favorable to efficiently increasing the charge of the desiccant.

8. The method of claim 7 where the heat source is solar.