A filter cartridge comprising filter media with an inner radial surface defining an outlet chamber therewithin and an outer radial surface defining an inlet chamber therearound.
A refueling system for an aircraft can generally comprise a hydrant (or other almost continuous source of fuel), and a vehicle that transfers fuel from the hydrant to the aircraft. A transfer vehicle (e.g., a cart or truck) can comprise, for example, a supply hose from the hydrant to its accouterment bank, and a delivery hose from the bank to the aircraft. The accouterment bank can comprise, among other things, a filter assembly for filtering the fuel prior to its delivery to the aircraft.
A filter cartridge comprises a fuse element that shuts the fuel exit should the filtering media become clogged or otherwise fail to pass fluid at an acceptable flow rate. The fuse element comprises a plastic poppet part that “blows” in response to the inlet-outlet pressure differential reaching a range corresponding to a filter-clogged scenario. The fuse element can be constructed without electrical circuits, biasing springs, complicated mechanical linkages, and/or precision instrumentation. Thus, the fuse element can be economically incorporated into a replaceable filter cartridge and, once the poppet has “blown”, it can be discarded with the filter cartridge and replaced.
Turning now to the drawings, and initially to
The filter assembly 100 is shown in
The housing 200 includes a capsule 210, an inlet pipe 220 extending radially thereinto, and an outlet pipe 230 extending axially therefrom. An inlet scaffold 240, and an outlet scaffold 250 can be suspended inside the capsule 200 to support opposite ends (i.e., the inlet end and the outlet end, respectively) of the filter cartridges 300. The inlet scaffold 240 (or other analogous structure) allow fuel introduced through the inlet pipe 220 to flow around the circumferences of the filter cartridges 300. The outlet scaffold 250 (or other analogous structure) allows only filtered fuel exiting the cartridges 300 to flow to the outlet pipe 230.
Referring now to
The filter element 400 defines an inlet chamber 401 and an outlet chamber 402, with the inlet chamber 401 communicating with the inlet pipe 220 in the filter assembly 100. The filter element 400 can comprise a cylindrical pack of filtering media 410 having an outer radial face 411 defining the inlet chamber 401 therearound, and an inner radial face 412 defining the outlet chamber 402 therewithin. The media 410 can be formed from, for example, one or more layers of filtration material folded into pleats and then shaped into the cylindrical pack.
The filter element 400 additionally comprises a first end cap 420, a second end cap 430, and a center sleeve 440. The first end cap 420 comprises a circular wall 421 bonded to and sealing the adjacent axial face of the filtering media 410, and also closing the adjacent end of the outlet chamber 402. (The illustrated cap 420 also includes a radial rim 422 surrounding the wall 421.) The second end cap 430 comprises an annular wall 431 bonded to a sealing the adjacent axial face of the filtering media 410, and leaving open the adjacent end of the outlet chamber 402. The center sleeve 440 includes a cage-like cylindrical wall 441 having a first hem 442 attached to the first end cap 420, and a second hem 443 attached to the second end cap 430.
The fuse element 500 is perhaps best explained by first referring to
The poppet 540 is movable from an open position (
When the poppet part 540 is in its opened position, it separates the pre-exit chamber 501 from the monitoring chamber 503. Filtered fluid flows from the outlet chamber 402 to the pre-exit chamber 501 and then through the exit door 502. (See arrows in
When the poppet part 540 is in its closed position, it seals the exit door 502. (
Referring additionally to
The poppet podium 520 has a dome-shaped side wall 521, tapering axially away from the canister's wall 513, and defining the fuse-monitoring chamber 503. The wall 521 has a central stem-receiving opening 523 on its peak that is coextensive with the canister's stem-receiving opening 516. A rim 524 can surround the base of the side wall 521, and a lip 525 can extend radially inward from the rim 524. The rim 524 and/or the lip 525 define an open end of the podium 420.
The corridor 550 comprises a cylindrical side wall 551 extending between the adjacent end cap 430 of the filter element 400 and the adjacent wall 513 of the canister 510. An internal corridor wall forms a stem-receiving opening 552 that is coextensive with canister/podium openings 516/523, and these openings 516/523/552 together form a passageway into the fuse-monitoring chamber 503. Internal walls 553 form tunnels in the corridor 550 extending through the cylindrical side wall 551 and to the stem-receiving opening 552. These tunnel-forming walls 553 define the monitoring channels 504, and connect the inlet chamber 401 to the monitoring chamber 503 (via the openings 516/523/552). The space within the cylindrical side wall 551, and not occupied by the internal walls 552/553, communicates with the exit chamber 501 via the fluid slots 5165 in the canister 510.
The exit annex 560 can comprise a cylindrical wall 561 extending axially away from the adjacent canister wall 514 and/or the exit door 502. A circumferential groove 562 can be formed in the wall 561, for receipt of a sealing member 563 (e.g., an O-ring). In the filter assembly 100, exit annex 560 would be received in an opening in the housing scaffold 250 (See
The poppet 540, shown alone in
Returning now to
The poppet's stem 545 is received within the openings 552/523/516 in the corridor 550, the podium 520, and the canister 510. (
When the poppet 540 is in its open position, inlet-pressure fluid within the monitoring chamber 503 pushes its side 542 toward the exit door 502 and outlet-pressure fluid within the exit chamber 501 pushes its side 543 in the opposite direction away from the exit door 502. (
However, should the filter media 510 become clogged (for example), the inlet pressure would rise and/or the outlet pressure would drop, thereby increasing the pressure differential between the inlet chamber 401 and the outlet chamber 402. With a rise in pressure differential, the push of the inlet-pressure fluid within the monitoring chamber 503 becomes strong enough to overcome the outlet-pressure fluid in the exit chamber 501, to bend the podium lip 525 in a releasing direction, and to dislodge the stem 545 from its press-fit connection.
The poppet 540 accordingly moves from its open position to its closed position, whereas it seals the exit door 502. (
Significantly, the filter cartridge 300 and/or the fuse element 500 does not provide a bypass or alternate exit path upon closing of the exit door 502. In a filter assembly 100 housing a single cartridge 300, this would result in halt in exit flow, thereby providing an indication that the filter cartridge 300 needs to be replaced. In a filter assembly 100 housing a plurality of filter cartridges 300, exit flow would continue from the remaining filter cartridges.
The poppet 540 and its staging within the podium 520 are thus designed so that the poppet 540 remains in its open position until a pressure differential between the inlet chamber 401 and the outlet chamber 402 reaches a predetermined range corresponding to clogging of the filter media 410. The “blow” point of the fuse element 500 can be altered by adjusting the relative surface areas between inlet-pressure side 542 and the outlet-pressure side 543 of the poppet head 540. Additionally or alternatively, the capture strength of the podium lip 525 can be modified and/or the press-fit stem connection can be changed. But, in any event, the fuse element 500 can be constructed without electrical circuits, biasing springs, complicated mechanical linkages, and/or precision instrumentation.
Referring now to
Although the filter assembly 100, the cartridge 300, the filter element 400, and/the fuse element 500 has been shown and described with respect to a certain embodiments, equivalent alterations and modifications should occur to others skilled in the art upon review of this specification and drawings. If an element (e.g., component, assembly, system, device, composition, method, process, step, means, etc.), has been described as performing a particular function or functions, this element corresponds to any functional equivalent (i.e., any element performing the same or equivalent function) thereof, regardless of whether it is structurally equivalent thereto. And while a particular feature may have been described with respect to less than all of embodiments, such feature can be combined with one or more other features of the other embodiments.
This application claims priority under 35 U.S.C. §119 (e) to U.S. Provisional Patent Application No. 61/036,616 filed on Mar. 14, 2008. The entire disclosure of this provisional application is hereby incorporated by reference. If incorporated-by-reference subject matter is inconsistent with subject matter expressly set forth in the written specification (and/or drawings) of the present disclosure, the latter governs to the extent necessary to eliminate indefiniteness and/or clarity-lacking issues.
Number | Date | Country | |
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61036616 | Mar 2008 | US |