Gas filters for acidic contaminants

• US 10,639,588 B2
• Filed: 08/26/2016
• Issued: 05/05/2020
• Est. Priority Date: 08/28/2015
• Status: Active Grant

• Current Assignee: Serionix, Inc.
• Original Assignee: Serionix, Inc.
• Inventors: Ba, Chaoyi, Zheng, Weihua, Diesel, Erich, Langer, James, Economy, James, Vaezian, Bita, He, Xinyu
• Primary Examiner(s): Griffin, Walter D.
• Assistant Examiner(s): Perez, Jelitza M
• Application Number:
  US15/756,041
• Publication Number:
  US 20190022581A1
• Time in Patent Office: 1,348 Days
• Field of Search: None
• CPC Class Codes: B01D 2251/2065 Ammonium hydroxide
• CPC Class Codes: B01D 2251/604 Hydroxides
• CPC Class Codes: B01D 2251/606 Carbonates
• CPC Class Codes: B01D 2257/302 Sulfur oxides
• CPC Class Codes: B01D 2257/304 Hydrogen sulfide
• CPC Class Codes: B01D 2257/306 Organic sulfur compounds, e.g. mercaptans
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/40 Acidic components B01D53/44 takes precedence
• CPC Class Codes: B01D 53/81 Solid phase processes
• CPC Class Codes: B32B 2255/00 Coating on the layer surface
• CPC Class Codes: B32B 2255/02 on fibrous or filamentary layer
• CPC Class Codes: B32B 2535/00 Medical equipment, e.g. bandage, prostheses or catheter
• CPC Class Codes: B32B 27/06 as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/20 using fillers, pigments, thixotroping agents
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08K 3/346 Clay
• CPC Class Codes: C09D 181/00 Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing sulfur, with or without nitrogen, oxygen, or carbon only; Coating compositions based on polysulfones; Coating compositions based on derivatives of such polymers

Abstract

An example article includes a substrate and a coating applied to the substrate. The coating may include a basic reactant and a humectant. The coating may further include a preservative or a water-soluble polymer. A coating configured to be applied to an acidic gas filter substrate may include K₂CO₃, potassium succinate, dehydroacetic acid, and poly(2-acrylamido-2-methyl-1-propanesulfonic acid (PAMPS). An example system includes an acidic gas filter including a coating, and a sensor configured to sense an optical change in the coating.

Claims

1. An article comprising an acidic gas heating, ventilation, and air conditioning (HVAC) filter configured to filter acidic components from a gas, the acidic gas HVAC filter comprising:

a substrate;

a coating applied to the substrate, wherein the coating comprises a basic reactant and a humectant, wherein the basic reactant comprises at least one of K₂CO₃, Na₂CO₃, KHCO₃, NaHCO₃, NaOH, and KOH; and

a stabilizer, wherein the stabilizer comprises a water-soluble polymer, and wherein the water-soluble polymer comprises poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS).

2. The article of claim 1, wherein the humectant is present in a weight ratio of about 1:

20 to about 1;

1 with respect to the basic reactant.

3. The article of claim 1, wherein the humectant comprises at least one salt comprising a sodium, potassium, or cesium salt of formate, acetate, nitrite, citrate, succinate, fluoride, glycolate, ascorbate, malonate, tartarate, gluconate, fumarate, sorbate, lactate, iminodiacetate, or malate.

4. The article of claim 1, wherein the coating comprises potassium succinate.

5. The article of claim 4, wherein the coating further comprises a preservative.

6. The article of claim 5, wherein the preservative is present in a weight ratio of about 1:

5000 to about 1;

10 with respect to the basic reactant.

7. The article of claim 5, wherein the preservative comprises at least one of potassium iodide, potassium nitrite, polyols, parabens, dehydroacetic acid, dehydroacetate salts, and benzoates.

8. The article of claim 5, wherein the preservative comprises dehydroacetic acid.

9. The article of claim 1, wherein the water-soluble polymer is present in a concentration between about 0.2 and about 20% by weight with respect to the coating.

10. The article of claim 1, wherein the water-soluble polymer further comprises at least one of metal polyacrylates, polyvinyl alcohol (PVA), polyacrylamide (PAM), poly(ethylene glycol) (PEG), polydiallyldimethylammonium chloride (PDADMAC), polymaleic acid, polyethylenimine (PEI), ethoxylated polyethylenimine (EPEI), poly(N-hydroxyethyl acrylamide) (PNHEA), and copolymers thereof.

11. The article of claim 9, wherein the water-soluble polymer has a molecular weight between about 5 million and about 10 million.

12. The article of claim 1, wherein the coating further comprises a pH indicator.

13. The article of claim 12, wherein the pH indicator comprises at least one of neutral red, phenol red, nitrazine yellow, bromophenol red, cresolphenol red, and brilliant yellow.

14. The article of claim 12, wherein the pH indicator comprises one or both of phenol red or nitrazine yellow.

15. The article of claim 1, wherein the substrate comprises a fibrous substrate.

16. The article of claim 1, wherein the coating at least partly impregnates a surface of the substrate.

17. The article of claim 1, wherein the stabilizer further comprises an inorganic stabilizer.

18. The article of claim 17, wherein the inorganic stabilizer comprises one or more of clay, nanoclay, bentonite, montmorillonite, or colloidal silica.

19. An article comprising an acidic gas heating, ventilation, and air conditioning (HVAC) filter configured to filter acidic components from a gas, the acidic gas HVAC filter comprising:

a fibrous substrate; and

a coating applied to the fibrous substrate, wherein the coating comprises;

a cross-linkable polymer and a cross-linker that form an ionic gel, poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS), and a basic reactant.

20. The article of claim 19, the coating further comprising at least one of potassium succinate and dehydroacetic acid.

21. The article of claim 19, the coating further comprising a color changing dye comprising one or more of neutral red, phenol red, nitrazine yellow, bromophenol red, cresolphenol red, and brilliant yellow.

22. The article of claim 19, wherein the cross-linkable polymer comprises alginate, and wherein the cross-linker comprises a calcium salt.

23. A system comprising:

an acidic gas heating, ventilation, and air conditioning (HVAC) filter comprising;

a coating on a substrate, wherein the coating comprises a basic reactant and a humectant, wherein the basic reactant comprises at least one of K₂CO₃, Na₂CO₃, KHCO₃, NaHCO₃, NaOH, and KOH, and

a stabilizer, wherein the stabilizer comprises a water-soluble polymer, and wherein the water-soluble polymer comprises poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS); and

a sensor configured to sense an optical change in the coating and generate a signal indicative of the optical change.

24. The system of claim 23, wherein the coating comprises a dye, and wherein the optical change is a change in a color of the dye.

25. The system of claim 24, wherein the dye comprises a pH indicator.