Modular filter elements for use in a filter-in-filter cartridge

1. A filter cartridge structured for coalescing a dispersed phase from a mixture of the dispersed phase in a continuous phase as the mixture moves through the cartridge from outside to inside, the cartridge comprising:

(a) an outer filter element, the outer filter element comprising:

(i) an outer pleated filter material where the outer pleated filter material has a substantially cylindrical shape and comprises thermoplastic composite material having a permeability of less than about 40 cfm, wherein the composite material is formed from at least the following layers:

(1) a top layer comprising a polymeric nonwoven, the top layer having a mean fiber diameter of >10 μm, the top layer having a higher porosity, a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately downstream of the top layer;

(2) a nanofiber layer comprising a polymeric nonwoven, the nanofiber layer having a mean fiber diameter of 0.1-1.0 μm, the nanofiber layer having a mean pore size of <8 μm; and the nanofiber layer having a maximum to mean pore size ratio of less than about 3; and

(3) a support layer comprising a polymeric nonwoven, the support layer having a mean fiber diameter of >20 μm, the support layer having a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately upstream of the support layer;

(ii) end caps attached to opposite ends of the outer pleated filter material; and

(b) an inner filter element located within the outer filter element; the inner filter element comprising:

(i) an outer non-pleated filter material where the outer non-pleated filter material has a substantially cylindrical shape;

(ii) an inner pleated filter material in contact directly or indirectly with the outer non-pleated filter material, wherein the inner pleated filter material has a substantially cylindrical shape and comprises thermoplastic composite material having a permeability of less than about 20 cfm, wherein the composite material is formed from:

(1) a top layer comprising a polymeric nonwoven, the top layer having a mean fiber diameter of >10 μm, the top layer having a higher porosity, a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately downstream of the top layer;

(2) a nanofiber layer comprising a polymeric nonwoven, the nanofiber layer having a mean fiber diameter of 0.1-1.0 μm, the nanofiber layer having a mean pore size of <8 μm; and the nanofiber layer having a maximum to mean pore size ratio of less than about 3; and

(3) a support layer comprising a polymeric nonwoven, the support layer having a mean fiber diameter of >20 μm, the support layer having a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately upstream of the support layer; and

(iii) end caps attached to opposite ends of the outer non-pleated filter material and the inner pleated filter material.

2. The cartridge according to claim 1 , wherein the outer filter element further comprises: (iii) an inner non-pleated filter material in contact directly or indirectly with the outer pleated filter material at inner pleat tips of the outer pleated filter material, wherein the inner non-pleated filter material has a substantially cylindrical shape and the end caps are attached to opposite ends of the inner non-pleated filter material.

3. The cartridge according to claim 2 , wherein the inner non-pleated filter material of the outer filter element comprises polymeric material.

4. The cartridge according to claim 3 , wherein the polymeric material is thermoplastic material.

5. The cartridge according to claim 2 , wherein the entire cartridge is polymeric material.

6. The cartridge according to claim 5 , wherein the polymeric material is thermoplastic material.

7. The cartridge according to claim 2 , wherein the outer filter element further comprises:

(iv) a support structure selected from a group consisting of a permeable tube, a screen, a spring, a cage-like structure, wherein the support structure contacts the inner non-pleated material of the outer filter element.

8. The cartridge according to claim 7 , wherein the support structure is located at the inner face of the inner non-pleated filter material of the outer filter element and the inner non-pleated filter material directly contacts the outer pleated filter material of the outer filter element at the inner pleat tips.

9. The cartridge according to claim 7 , wherein the support structure is located at the outer face of the inner non-pleated filter material of the outer filter element and the inner non-pleated filter material indirectly contacts the outer pleated filter material of the outer filter element at the inner pleat tips via the support structure.

10. The cartridge according to claim 1 , wherein the outer pleated filter material of the outer filter element has slits or holes in valleys of the pleated filter material.

11. The cartridge according to claim 1 , wherein the outer non-pleated filter material of the inner filter element comprises polymeric material.

12. The cartridge according to claim 11 , wherein the polymeric material is thermoplastic material.

13. The cartridge according to claim 1 , wherein the entire cartridge is polymeric material.

14. The cartridge according to claim 13 , wherein the polymeric material is thermoplastic material.

15. The cartridge according to claim 1 , wherein the nanofiber layer comprises polyamide material.

16. The cartridge according to claim 1 , wherein the outer pleated filter material is formed by physically or chemically coupling the top layer, the nanofiber layer, and the bottom layer.

17. The cartridge according to claim 1 , wherein the outer pleated filter material is formed by electroblowing a media material and combining the electroblown media material and another media material in layers.

18. The cartridge according to claim 1 , wherein the cartridge is configured for coalescing water dispersed in a continuous phase of hydrocarbon fuel.

19. The cartridge according to claim 18 , wherein the outer non-pleated filter material of the inner filter element is hydrophobic.

20. The cartridge according to claim 18 , where a drop of water in the hydrocarbon fuel has a contact angle on the outer non-pleated filter material of the inner filter element that is no less than 90°.

21. The cartridge according to claim 1 , wherein the end caps comprise polymeric material.

22. The cartridge according to claim 21 , wherein the polymeric material is thermoplastic material.

23. The cartridge according to claim 1 contained in a housing, the housing having an upstream inlet structured to receive the mixture, a downstream outlet structured to discharge the mixture after coalescing of the dispersed phase, and a downstream outlet structured to discharge the coalesced dispersed phase.

24. A fuel water separation system comprising the cartridge according to claim 1 .

25. The fuel water separation system according to claim 24 , structured for removing water dispersed in hydrocarbon fuel.

26. The fuel water separation system according to claim 24 , further comprising a hydrophobic media for removing water positioned downstream of the cartridge.

27. The fuel water separation system according to claim 24 , further comprising an additional device for removing water positioned downstream of the filter cartridge, the device selected from a group consisting of gravity separator, centrifuge, impactor, lamella separator, inclined stacked plate, screen, water absorber, and quiescent chamber.

28. The cartridge according to claim 1 , wherein the outer filter element further comprises a permeable tube, a screen, a spring, and a cage-like structure downstream of the outer pleated filter material.

29. A method of removing water dispersed in hydrocarbon fuel, the method comprising passing a mixture comprising hydrocarbon fuel and water dispersed in the hydrocarbon fuel through the filter cartridge of claim 1 and removing at least about 95% of water dispersed in the hydrocarbon fuel.

30. A thermoplastic filter-in-filter cartridge comprising an outer filter element and an inner filter element,

the outer filter element comprising:

(a) an outer pleated filter material where the outer pleated filter material has a substantially cylindrical shape and comprises thermoplastic composite material, and

wherein the composite material is formed from at least the following layers:

(1) a top layer comprising a polymeric nonwoven, the top layer having a mean fiber diameter of >10 μm, the top layer having a higher porosity, a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately downstream of the top layer;

(2) a nanofiber layer comprising a polymeric nonwoven, the nanofiber layer having a mean fiber diameter of 0.1-1.0 μm, the nanofiber layer having a mean pore size of <8 μm; and the nanofiber layer having a maximum to mean pore size ratio of less than about 3; and

(3) a support layer comprising a polymeric nonwoven, the support layer having a mean fiber diameter of >20 μm, the support layer having a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately upstream of the support layer;

(b) end caps attached to opposite ends of the outer pleated filter material; and

(c) optionally one of:

(i) an inner non-pleated filter material in contact directly or indirectly with the outer pleated filter material at inner pleat tips of the outer pleated filter material, wherein the inner non-pleated filter material has a substantially cylindrical shape and the end caps are attached to opposite ends of the inner non-pleated filter material; and

(ii) slits or holes in valleys of the pleated filter material; and

the inner filter element comprising:

(a) an outer non-pleated filter material where the outer non-pleated filter material has a substantially cylindrical shape;

(b) an inner pleated filter material in contact directly or indirectly with the outer non-pleated filter material, wherein the inner pleated filter material has a substantially cylindrical shape and comprises thermoplastic composite material; and

wherein the composite material is formed from at least the following layers:

(1) a top layer comprising a polymeric nonwoven, the top layer having a mean fiber diameter of >10 μm, the top layer having a higher porosity, a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately downstream of the top layer;

(2) a nanofiber layer comprising a polymeric nonwoven, the nanofiber layer having a mean fiber diameter of 0.1-1.0 μm, the nanofiber layer having a mean pore size of <8 μm; and the nanofiber layer having a maximum to mean pore size ratio of less than about 3; and

(3) a support layer comprising a polymeric nonwoven, the support layer having a mean fiber diameter of >20 μm, the support layer having a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately upstream of the support layer; and

(c) end caps attached to opposite ends of the outer non-pleated filter material and the inner pleated filter material.

31. The cartridge according to claim 30 , wherein the outer filter element further comprises a permeable tube, a screen, a spring, and a cage-like structure downstream of the outer pleated filter material.

32. A filter element comprising:

(a) an outer pleated filter material where the outer pleated filter material has a substantially cylindrical shape and comprises thermoplastic composite material;

(b) end caps attached to opposite ends of the outer pleated filter material; and optionally one of:

(i) an inner non-pleated filter material in contact directly or indirectly with the outer pleated filter material at inner pleat tips of the outer pleated filter material, wherein the inner non-pleated filter material has a substantially cylindrical shape; and

(ii) slits or holes in valleys of the pleated filter material;

wherein the composite material is formed from at least the following layers:

(1) a top layer comprising a polymeric nonwoven, the top layer having a mean fiber diameter of >10 μm, the top layer having a higher porosity, a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately downstream of the top layer;

(2) a nanofiber layer comprising a polymeric nonwoven, the nanofiber layer having a mean fiber diameter of 0.1-1.0 μm, the nanofiber layer having a mean pore size of <8 μm; and the nanofiber layer having a maximum to mean pore size ratio of less than about 3; and

(3) a support layer comprising a polymeric nonwoven, the support layer having a mean fiber diameter of >20 μm, the support layer having a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately upstream of the support layer.

33. The filter element according to claim 32 , wherein the filter element is an outer filter element structured for use in a filter-in-filter cartridge.

34. The filter element according to claim 32 , further comprising a permeable tube, a screen, a spring, and a cage-like structure downstream of the outer pleated filter material.

35. A filter element comprising:

(a) an outer non-pleated filter material where the outer non-pleated filter material has a substantially cylindrical shape and comprises thermoplastic hydrophobic material;

(b) an inner pleated filter material in contact directly or indirectly with the outer non-pleated filter material, wherein the inner pleated filter material has a substantially cylindrical shape and comprises thermoplastic composite material; and

(c) end caps attached to opposite ends of the outer non-pleated filter material and the inner pleated filter material;

wherein the composite material is formed from at least the following layers:

(1) a top layer comprising a polymeric nonwoven, the top layer having a mean fiber diameter of >10 μm, the top layer having a higher porosity, a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately downstream of the top layer;

(2) a nanofiber layer comprising a polymeric nonwoven, the nanofiber layer having to mean fiber diameter of 0.1-1.0 μm, the nanofiber layer having a mean pore size of <8 μm; and the nanofiber layer having a maximum to mean pore size ratio of less than about 3; and

(3) a support layer comprising a polymeric nonwoven, the support layer having a mean fiber diameter of >20 μm, the support layer having a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately upstream of the support layer.

36. The filter element according to claim 35 , wherein the filter element is an inner filter element structured for use in a filter-in-filter cartridge.