Two stage filter cartridge with an expandable frame facilitating replacement of the filter media
The present invention is related to a liquid filter having a filtration part for filtration of liquid, said filtration part at least comprising a first filtration layer consisting of a first material; and a second filtration layer consisting of a second material, characterized in that the filtration of liquid in the filtration part is in the order of: a first filtration, taking place at said second filtration layer; and a second filtration, taking place at said first filtration layer. The present invention is further related to a method for installing the liquid filter.
1 . A cylindrical liquid filter cartridge ( 500 ) comprising:
a first filtration layer ( 520 ) consisting of a first material;
a second filtration layer ( 530 ) consisting of a second material, the second filtration layer ( 530 ) having cross-sectional thickness with an outer circumferential cross-section defining a plurality of recessed portions ( 525 ) disposed around an elongate cylindrical perimeter, and an interior surface defining a central cylindrical channel ( 512 ), the first filtration layer ( 520 ) being coextensively laid over an outer peripheral surface of the elongate cylindrical perimeter of the second filtration layer ( 530 ), such that the shape of said first filtration layer after installation is the same as the peripheral shape of said second filtration layer;
a circular end cap inlet ( 510 ) having a port ( 505 ) in fluid communication with the central cylindrical channel ( 512 ) permitting fluid flow through the circular end cap inlet ( 510 );
a circular base member ( 440 ) having a vertically extending peripheral wall radially disposed about a central axis; and
a frame ( 550 ) including a plurality of elongate frame members each directly attached to the vertically extending peripheral wall of the circular base member ( 440 ) at a lower end of the filter cartridge ( 500 ), and each having a notch portion ( 540 ) at the opposing upper end that is sized and shaped for removable, engageable insertion within an interior of the circular end cap inlet ( 510 );
wherein, each of the plurality of elongate frame members extend from the circular base member ( 440 ) through a respective one of the plurality of recessed portions ( 525 ), to the circular end cap inlet ( 510 ), when the respective notch portions ( 540 ) are insertably engaged within the interior of the circular end cap inlet ( 510 ), and at the opposing upper end of the frame ( 550 ), the plurality of elongate frame members are radially spaced from the central axis of the circular base member ( 440 ) defining an opening which is larger than an interior diameter of the frame ( 550 ) at the lower end of the filter cartridge ( 500 ), facilitating insertion the first filtration layer ( 520 ) and the second filtration layer ( 530 ) into an interior of the frame ( 550 ), when the respective notch portions ( 540 ) are not insertably engaged within the interior of the circular end cap inlet ( 510 ).
2 . The cylindrical liquid filter cartridge according to claim 1 , characterized in that the recessed portions of the outer circumferential cross-section of said second filtration layer define a first geometric shape.
3 . The cylindrical liquid filter cartridge according to claim 2 , characterized in that said first geometric shape is a star-shaped or wave-shaped polygon.
4 . The cylindrical liquid filter cartridge according to claim 2 , characterized in that an inner circumferential cross-section of said frame defines a second geometric shape, wherein, after said first filtration layer is arranged along the length of said elongate cylindrical perimeter, said first filtration layer is in contact with the periphery of said second filtration layer along the length of said frame, such that the cross-section of said first filtration layer assumes said first geometric shape and/or said second geometric shape.
5 . The cylindrical liquid filter cartridge according to claim 4 , characterized in that said second geometric shape is a star-shaped or wave-shaped polygon.
6 . The cylindrical liquid filter cartridge according to claim 4 , characterized in that said first geometric shape and said second geometric shape are the same.
7 . The cylindrical liquid filter cartridge according to claim 1 , characterized in that, a pore size of said first filtration layer is smaller than a pore size of said second filtration layer, such that liquid introduced through the port enters the central cylindrical channel, flows through the second filtration layer, and then through the first filtration layer, resulting in a filtered liquid.
8 . The cylindrical liquid filter cartridge according to claim 1 , characterized in that, said first material is nanofiber selected from the group consisting of: nylon, n-polyacrylonitrile, polyurethane, or the combinations thereof; and said second material is activated carbon.
9 . The cylindrical liquid filter cartridge according to claim 1 , characterized in that, said first filtration layer and said second filtration layer can be independently assembled.