COMPOSITE DESICCANT AND AIR-TO-WATER SYSTEM AND METHOD

• US 20110232485A1
• Filed: 03/28/2011
• Published: 09/29/2011
• Est. Priority Date: 03/26/2010
• Status: Active Grant

• Current Assignee: Joseph Ellsworth
• Original Assignee: Joseph Ellsworth
• Inventors: Ellsworth, Joseph
• Granted Patent: US 8,506,675 B2
• Time in Patent Office: Days
• US Class Current: 95/91
• 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 CaCl. 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 H₂O from atmospheric gas flowing through that chamber. In a regeneration state atmospheric flow is stopped and low-grade energy releases the H₂O from the desiccant into that chamber. Fans circulate moist air through the main chamber and into an adjacent chamber for H₂O transfer through or past a partially permeable barrier into a cooling/condensing area. Both H₂O and dry gas may be produced.

Claims

1. A sorbent composition of matter substantially consisting of:

a porous sheet of an absorbent material, in which an hygroscopic material is disbursed in a non-captive manner; and

wherein said absorbent sheet is planar with a generally uniform thickness of between 0.1 mm and 12 mm;

further a porous absorbent material has a pore structure of a range of pore sizes including pores of about 100 microns and pores of about 1000 microns.

2. The sorbent sheet of matter of claim 1 having an upper surface and a lower surface and the following properties:

in a gaseous environment comprising water vapor, with a flow rate between 1 FPM and 100 FPM across both top and bottom surfaces in an environment between 70 F@60% RH and 70 F@99% RH, said sorbent sheet, if substantially dried before starting will absorb 20% to 70% of its weight in the first hour and 120% to 350% of its weight in the first 10 hours.

3. The composition of matter of claim 1 wherein said hygroscopic material comprises one or more substances chosen from a list consisting of calcium chloride and glycol.

4. The composition of matter of claim 1 wherein said hygroscopic material comprises one or more substances chosen from a list consisting of calcium fluoride, zinc bromide, potassium hydroxide, sodium hydroxide, lithium iodine, potassium acetate, lithium chloride, lithium bromide, and magnesium chloride.

5. The composition of matter as in claim 1 in which said porous sheet is substantially comprised by one or more materials from a list consisting of PVA foam and non-woven rayon cloth.

6. The composition of matter as in claim 1 in which said porous sheet is substantially comprised by one or more materials from a list consisting of:

micro fiber cloth, open cell foam, cloth, and mulched cellulose.

7. The composition of matter as in claim 1 wherein said sheet comprises PVA foam and said hygroscopic material comprises CaCl and further, by weight, said PVA foam is between 50% and 400% of the combined weight.

8. A sorbent material produced by the actions comprising:

(a) soaking a sheet of an absorbent material in a solution of a concentration between 10% and 60% by weight of a hygroscopic chemical mixed with water;

(b) removing the sheet from the solution;

(c) drying the sheet while suspended flat with its major plane perpendicular to the force of gravity.

9. A sorbent material produced by the actions comprising those of claim 8 wherein the absorbent material is a PVA sheet and further, the hygroscopic chemical material is substantially comprised of CaCl.

10. A sorbing component comprising:

a plurality of generally flat sorbent sheets arranged stacked one above the other in a mutually parallel fashion with inter-sheet spacing of between 1 mm and 20 mm;

the composition of the sheets comprising a porous support material containing a disbursed hygroscopic material further, said stack configured such that air flow through its inter-sheet spaces is restricted to one major direction by the substantial blocking of two opposite sides.

11. The sorbing component of claim 10 further comprising air turbulence inducing members within at least one of the inter-sheet spaces.

12. A sorbing component as in claim 10 so configured as to provide for the major planes of said sheets to be aligned perpendicular to the vector of gravity and acceleration in its intended use environment.

13. A sorbing component as in claim 10 wherein said hygroscopic material comprises CaCl and said hygroscopic material comprises a PVA foam.

15. The method of producing a sorbent component of claim 13 wherein the sorbent sheet comprises a PVA foam and further, the chemical desiccant comprises CaCl.

14. A method of producing a sorbent component comprising the actions of:

(a) mounting a plurality of absorbent sheets in a mutually parallel fashion with a generally uniform inter-sheet spacing;

(b) soaking the mounted sheets in a solution of a chemical desiccant until an effective amount of the chemical desiccant is contained within the sheets;

(c) removing the mounted sheets from the solution;

(d) drying in a position with the sheets perpendicular to the vector of gravity.

16. A method of drying a gas wherein the gas to be dried flows between a plurality of juxtaposed flat layers of an absorbent sheet material that is permeated by a hygroscopic desiccant.

17. A gas drying system comprising:

(a) a stack of sorbent, spaced, parallel sheets, the sheets comprised of an absorbent substrate containing a non-captive hydroscopic material;

(b) a main chamber containing said stack and so configured as to provide at least one path for airflow from outside said main chamber, into said main chamber, through the inter-sheet space of said stack 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 inter-sheet space of said stack and back to said heating chamber.

18. The system of claim 17 further comprising a third, 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.

19. The system of claim 18 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 opposing side of the semi-permeable element forms at least a portion of an enclosing wall of a condensing chamber.

20. A system as in claim 19 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.

21. The system of claim 18 with said separating chamber being so configured as to provide for a flow substantially normal to the semi-permeable element'"'"'s major plane and wherein the opposing side of the semi-permeable element forms at least a portion of an enclosing wall of a condensing chamber.

22. A system for producing water from air comprising:

a) a desiccant component comprising a plurality of sorbent sheets with means for supporting them horizontally;

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

c) means for exposing the desiccant sheets to a source of heat;

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

the closed-loop path having a defining wall portion of a semi-permeable material;

e) means for engendering a second closed-loop flow, the path of this second flow having a semi permeable wall in common with the first closed-loop flow;

f) means for condensing water vapor in the second closed-loop flow into liquid water.

23. A sorbent composition of matter comprising of:

a sheet of an absorbent material in which an hygroscopic material is disbursed in a non-captive manner; and

wherein said absorbent sheet is planar with a generally uniform thickness of between 0.1 mm and 12 mm;

further, the absorbent material has a random gap structure of a range of gap sizes including gaps of about 100 microns and gaps of about 1000 microns.