Filter water management using hydrophilic material
View Patent ↗A media comprising a hydrophobic media layer and a hydrophilic matrix applied to one face of the hydrophobic media layer is provided. The media may be incorporated into a filter cartridge for an air filtration system for a gas turbine engine. The media may have the capability to wick droplets of water.
1. An apparatus comprising a filter comprising media, the media comprising:
a hydrophobic media layer having opposed first and second faces,
a hydrophilic matrix along the first face of the hydrophobic media, the first face of the hydrophobic media having a first portion obstructed by the hydrophilic matrix and a second portion exposed through open areas defined by the hydrophilic matrix.
2. The apparatus of claim 1 , wherein the hydrophobic media comprises a porous membrane comprising at least one of ePTFE, PTFE, and stretched film filter media, the membrane having an average pore size of between 0.01 microns and 10 microns, and an air flow permeability of at least 0.1 CFM measured per ASTM D737.
3. The apparatus of claim 1 , wherein the hydrophobic media comprises a porous fibrous entanglement comprising fibers formed from at least one of polyolefin, polyamide, polyester, polysulfone, polyether, acrylic, methacrylic, polystyrene, polyurethane, polypropylene, polyethylene, expanded polytetrafluoroethylene (ePTFE), Woven PTFE, and non-Woven PTFE, the porous fibrous entanglement having an average pore size of between 0.01 microns and 10 microns, and an air flow permeability of at least 0.1 CFM measured per ASTM D737.
4. The apparatus of claim 1 , wherein the open areas comprise greater than 50%, such that greater than 50% of the first face of the hydrophobic media is exposed.
5. The apparatus of claim 1 , wherein the open areas comprise greater than 75%, such that greater than 75% of the first face of the hydrophobic media is exposed.
6. The apparatus of claim 1 , wherein the hydrophilic matrix only obstructs between 5% and 15% of the first face of the hydrophobic media.
7. The apparatus of claim 1 , wherein the hydrophilic matrix comprises a plurality of continuous or discontinuous strips, each of the plurality of strips having a width of between 0.05 and 2 millimeters, a length longer than the width, and a depth thickness of between 0.05 and 2 millimeters.
8. The apparatus of claim 1 , wherein the hydrophilic matrix comprises a plurality of continuous or discontinuous strips, each of the plurality of strips spanning an entire width and length span of the media.
9. The apparatus of claim 1 , wherein the hydrophobic media has an average pore size of between 0.01 microns and 10 microns, an air flow permeability of at least 0.1 CFM measured per ASTM D737, an air flow capacity of approximately 3 to 10 CFM at 0.5 inch of water gauge pressure drop, and having an initial filtration efficiency of at least 99.0% for 0.3 micron sized aerosol particles measured by ASTM D6830.
10. The apparatus of claim 1 , wherein the hydrophilic matrix comprising a chemical deposition imprint of at least one of an amine-containing hydrophilic polymer.
11. The apparatus of claim 1 , wherein a permanent hydrophilic treatment is imparted to the hydrophilic matrix employing a cross-linking polymer.
12. The apparatus of claim 1 , wherein the hydrophilic matrix comprises deposition of fibers comprising fibers of polyactides or other polymers with hydrophilic coatings.
13. The apparatus of claim 12 , wherein the fibers are entangled with the hydrophobic media layer along the first side of the hydrophobic media layer.
14. The apparatus of claim 1 , wherein the hydrophilic matrix creates less than a 10% restriction to the hydrophobic media layer, measured through an air flow range of between 3 to 10 CFM at 0.5 inches of pressure drop.
15. An air filtration system for a gas turbine engine or industrial application, including the apparatus of claim 1 , the system comprising:
an air inlet housing assembly arranged upstream of the gas turbine engine or industrial application, arranged to filter combustion air flowing to the gas turbine engine or industrial application;
wherein the filter is a filter cartridge arranged in the air inlet housing assembly;
wherein the hydrophobic media layer has an average pore size of between 0.01 microns and 10 microns, and an air flow permeability of at least 0.1 CFM measured per ASTM D737, an air flow capacity of approximately 3 to 10 CFM at 0.5 inch of water gauge pressure drop, and having an initial filtration efficiency of at least 99.0% for 0.3 micron sized aerosol particles measured by ASTM D6830.
16. The air filtration system of claim 15 , further comprising a back pulse arrangement arranged to pulse air through the filter cartridge to release dust.
17. A method of operating the air filtration system for a gas turbine engine or industrial application of claim 15 , comprising:
drawing air through the filter cartridge, the air being subject to periodic extended periods of fog having water droplets with an average droplet size of between about 1 and about 5 microns size in diameter;
wicking away the water droplets from pores in the hydrophobic media layer via the hydrophilic matrix.
18. The apparatus of claim 10 , wherein the amine-containing hydrophilic polymer comprises a polyvinyl alcohol-coamine polymer.
19. The apparatus according to claim 1 , wherein:
the hydrophobic media layer comprises at least one of a porous membrane and a porous woven or non-woven fiber entanglement having an average pore size of between 0.01 microns and 10 microns and an air flow permeability of at least 0.1 CFM measured per ASTM D737; and
the hydrophilic matrix comprises hydrophilic channels integral with the hydrophobic media layer, the open areas defined between the hydrophilic channels, wherein air flow can pass through the open areas between the first and second faces without passing through the hydrophilic channels.
20. The apparatus of claim 19 , wherein the hydrophobic media layer comprises at least one of ePTFE, PTFE, fluorine containing polymeric fibers, or polymeric fibers with a hydrophobic treatment.
21. The apparatus of claim 19 , wherein the second face of the hydrophobic media layer is laminated to a carrier layer for structural support, the carrier layer alone providing greater support characteristics relative to the hydrophobic media layer alone, the carrier layer including an average fiber size at least 4 times larger in diameter than an average fiber or fibril size of the hydrophobic media layer and an average pore size at least 4 times larger than the filter media.
22. The apparatus of claim 21 , wherein the hydrophilic channels are formed or deposited upon the first face that forms an upstream face for the hydrophobic media layer.
23. The apparatus of claim 19 , wherein the open areas comprise greater than 75%, such that greater than 75% of the air flow through the hydrophobic filter media can bypass the hydrophilic channels.
24. The apparatus of claim 19 , wherein the hydrophilic channels comprises a plurality of continuous or discontinuous strips, each of the plurality of strips having a width of between 0.05 and 2 millimeters, a length longer than the width, and a depth thickness of between 0.05 and 2 millimeters.
25. The apparatus of claim 24 , wherein the strips are continuous and extend primarily vertically to facilitate gravitational drainage.
26. The apparatus of claim 19 , wherein the hydrophobic media layer includes an air flow capacity of approximately 3 to 10 CFM at 0.5 inch of water gauge pressure drop, and having an initial filtration efficiency of at least 99.0% for 0.3 micron sized aerosol particles measured by ASTM D6830, and wherein the hydrophilic channels create less than a 10% restriction to the hydrophobic media layer, measured through an air flow range of between 3 to 10 CFM at 0.5 inches of pressure drop.