Humidity control device

• US 7,959,719 B2
• Filed: 01/29/2009
• Issued: 06/14/2011
• Est. Priority Date: 11/09/2004
• Status: Active Grant

• Current Assignee: Multisorb Technologies Incorporated (FGI Equity LLC)
• Original Assignee: Multisorb Technologies Incorporated (FGI Equity LLC)
• Inventors: Powers, Thomas H., Patrone, Louis
• Primary Examiner(s): LAWRENCE JR, FRANK M
• Application Number:
  US12/362,253
• Publication Number:
  US 20100025629A1
• Time in Patent Office: 866 Days
• Field of Search: 961/08, 961/18, 961/19, 961/47, 252/194, 252/188.28, 502/405, 502/417, 206/204, 95/91
• US Class Current: 96/118
• CPC Class Codes: B01D 2257/104 Oxygen
• CPC Class Codes: B01D 2257/80 Water
• CPC Class Codes: B01D 53/28 Selection of materials for use as drying agents
• CPC Class Codes: B01J 20/043 Carbonates or bicarbonates, e.g. limestone, dolomite, aragonite
• CPC Class Codes: B01J 20/045 containing sulfur, e.g. sulfates, thiosulfates, gypsum
• CPC Class Codes: B01J 20/046 containing halogens, e.g. halides
• CPC Class Codes: B01J 20/103 comprising silica
• CPC Class Codes: B01J 20/20 comprising free carbon; comprising carbon obtained by carbonising processes
• CPC Class Codes: B01J 20/28014 characterised by their form
• CPC Class Codes: B01J 20/2803 Sorbents comprising a binder, e.g. for forming aggregated, agglomerated or granulated products
• CPC Class Codes: B01J 20/28042 Shaped bodies; Monolithic structures
• CPC Class Codes: B01J 20/2805 Sorbents inside a permeable or porous casing, e.g. inside a container, bag or membrane
• CPC Class Codes: B01J 20/3035 Compressing
• CPC Class Codes: B01J 20/3042 Use of binding agents; addition of materials ameliorating the mechanical properties of the produced sorbent
• CPC Class Codes: B01J 20/3078 Thermal treatment, e.g. calcining or pyrolizing
• CPC Class Codes: B01J 20/3204 Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/3208 Polymeric carriers, supports or substrates
• CPC Class Codes: B01J 20/3212 consisting of a polymer obtained by reactions otherwise than involving only carbon to carbon unsaturated bonds
• CPC Class Codes: B01J 20/3236 containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts
• CPC Class Codes: B01J 20/3293 Coatings on a core, the core being particle or fiber shaped, e.g. encapsulated particles, coated fibers
• CPC Class Codes: B01J 2220/42 : Materials comprising a mixture of inorganic materials materials coated or impregnated on a carrier B01J20/32
• CPC Class Codes: B01J 2220/46 : Materials comprising a mixture of inorganic and organic materials materials coated or impregnated on a carrier B01J20/32
• CPC Class Codes: B01J 2220/4843 : Algae, aquatic plants or sea vegetals, e.g. seeweeds, eelgrass

Abstract

A device for controlling relative humidity in an environment with a solidified humectant composition. The solidified humectant composition is made from a humectant salt, water, and a carrier. The solidified humectant may be formed into a tablet with the aid of a binder, or it may be contained within a thermoformed felt material, a sachet, or a water permeable canister. In a preferred embodiment, the sachet is made of a micro-perforated polyester/paper/polyethylene material. Preferred humectant salts include CaCl₂, K₂CO₃, LiCl, NaCl, K₂SO₄, and combinations thereof. A preferred embodiment of the present invention includes the use of one or more of: an antimicrobial agent, activated carbon, a volatile organic, a moisture adsorber and an oxygen absorber, in combination with the solidified humectant salt.

Claims

1. A device for adsorbing and releasing moisture to produce and maintain a desired equilibrium relative humidity in an environment comprising:

a carrier in a continuous solid phase, the carrier including;

a water adsorbed into the carrier; and

a humectant salt having a portion dissolved in the water forming a saturated solution and an excess portion in solid form, the humectant salt and the carrier selected such that the combination produces the desired equilibrium relative humidity, wherein the device maintains the desired equilibrium relative humidity by changing the ratio of the dissolved portion of humectant salt to excess portion of humectant salt and wherein at least some excess portion always remains.

2. The device of claim 1 further comprising a binder which is different from the carrier.

3. The device of claim 2 wherein the device is in a tablet form.

4. The device of claim 3 wherein the tablet is coated with a water-vapor permeable coating.

5. The device of claim 4 wherein the coating is selected from the group consisting of polyethylene, polytetrafluoroethylene, polyvinylprollidone and cellulose ether.

6. The device of claim 1 wherein the humectant salt is selected from the group consisting of CaCl₂, K₂CO₃, NaCl, K₂So₄, LiCl and combinations thereof.

7. The device of claim 1 further comprising an antimicrobial agent.

8. The device of claim 1 wherein the carrier is selected from the group consisting of cellulose, silica gel, clay, carbohydrate or protein gelling agent, hydrocolloid gum, and hydrophilic polymers.

9. The device of claim 1 further comprising activated carbon.

10. The device of claim 1 further comprising an oxygen absorber.

11. The device of claim 2 wherein the binder is selected from the group consisting of polyvinylprollidone, a thermoplastic resin, a wax, and combinations thereof.

24. The device of claim 2 wherein the binder is selected from the group consisting of polyvinylpyrollidone, a thermoplastic resin, a wax, and combinations thereof and wherein the carrier is selected from the group consisting of cellulose, silica gel, clay, carbohydrate or protein gelling agent, hydrocolloid gum, and hydrophilic polymers.

25. The device of claim 1 wherein the carrier is selected from the group consisting of materials that will stabilize, solidify, encapsulate or absorb the humectant in a solid state.

12. A device for adsorbing and releasing moisture to produce and maintain a desired equilibrium relative humidity in an environment comprising:

a water vapor-permeable container; and

a solidified humectant composition within the container, the solidified humectant composition comprising;

a carrier in a continuous solid phase, the carrier including;

a water adsorbed into the carrier;

a humectant salt having a portion dissolved in the water forming a saturated solution and an excess portion of humectant salt in solid form, the humectant salt and the carrier selected such that the combination produces the desired equilibrium relative humidity, wherein the device maintains the desired equilibrium relative humidity by changing the ratio of the dissolved portion of humectant salt to excess portion of humectant salt and wherein at least some of the excess portion of humectant salt always remains.

13. The device of claim 12 wherein the container is comprised of a thermoformed felt material.

14. The device of claim 12 wherein the container is in the form of a sachet.

15. The device of claim 12 wherein the container is in the form of a canister.

16. The device of claim 14 wherein the sachet is comprised of micro-perforated polyester/paper/polyethylene material.

17. The device of claim 15 wherein the canister is perforated or is made partially or completely of a microporous sintered material.

18. The device of claim 12 wherein the humectant salt is selected from the group consisting of CaCl₂, K₂CO₃, LiCl, NaCl, K₂SO₄, and combinations thereof.

19. The device of claim 12 further comprising an antimicrobial agent in the container.

20. The device of claim 12 wherein the carrier is selected from the group consisting of cellulose, silica gel, clay, carbohydrate or protein gelling agent, hydrocolloid gum, and hydrophilic polymers.

21. The device of claim 12 wherein the solidified humectant composition further comprises activated carbon.

22. The device of claim 12 wherein the solidified humectant composition further comprises an oxygen absorber.

23. The device of claim 12 wherein the container comprises a sealed body having a breather port thereon.

26. The device of claim 12 wherein the carrier is selected from the group consisting of materials that will stabilize, solidify, encapsulate or absorb the humectant in a solid state.