[001] The invention relates to apparatuses for separating fluids of different specific gravities, such as fuel-water separators. In particular, the invention provides apparatuses for retaining water that has been separated from a fuel-water mixture by a fuel-water separator.

Background

[002] The presence of water and particulate contaminants in fuel is a problem that is well known. It has been found that problems arising from water and particulate contaminants are magnified in fuel injection systems of internal combustion engines.

[003] Apparatuses for separating water and / or particulate contaminants from fuel- water mixtures are known within the art, and are typically implemented in the form of a fuel-water separator (optionally combined with one or more filters). A fuel-water separator may be positioned on the fuel line, so that fuel passes through the fuel-water separator prior to entering the FIP (fuel injection pump) and thereafter the engine. A fuel-water separator may comprise a housing having a fluid selective barrier media disposed therein to separate fuel from water. The fluid selective barrier media may comprise a hydrophobic filtration element, which allows passage of fuel onward to the engine, while preventing water from passing through.

[004] Given the differing specific gravities of water and fuel, the separated water component of the fuel-water mixture tends to settle at the bottom of the fuel-water separator housing, from where it can be removed through a drain or outlet at the lowest point of the housing. Draining water from a fuel-water separator may comprise opening a stop-cock or drainage valve in the housing to enable drainage.

[005] A problem with prior art devices is that water setded at the bottom of the fuel- water separator tends to emulsify (or re-emulsify) with the fuel-water mixture (due to engine or vehicle vibrations). This re-entrainment increases the water content within the

1 fuel-water mixture, which further challenges the performance of the hydrophobic barrier media. Further, as the volume of water accumulated at the bottom of the fuel-water separator increases, severity of the re-entrainment increases. Accordingly, accumulated water requires to be drained or otherwise removed from fuel-water separators on a regular basis.

[006] To ensure that accumulated water is periodically drained, drainage outlets in fuel- water separators may be provided with mechanical and / or electronic valve opening mechanisms which periodically open the drainage outlet(s). Likewise, to ensure that water levels remain below the level of the hydrophobic barrier media, one or more sensors may be provided witliin the fuel-water separator, which sensors may be configured to generate a signal (e.g. alert signal, alarm signal or other state change signal) when the accumulated water reaches a certain level. It has however been found that over time, exposure to particulate matter arid/ or other impurities within fuel-water mixtures results in clogging of electronic sensors and valve opening actuators that are located within the fuel-water separator, which limits their effectiveness. As water at the bottom of a fuel-water separator accumulates beyond desirable levels, performance of the electronic sensors and /or actuators has been found to deteriorate significantly.

[007] Additionally, even with the implementation of such sensors and / or actuators, water that accumulates between drainage events within the fuel-water separator tends to re-emulsify with the incoming fuel-water mixture, which for the reasons discussed above has negative consequences for performance of the fuel-water separator.

[008] There is accordingly a need for an apparatus that prevents water that has been separated by the fuel-water separator from re- emulsifying with the incoming fuel-water mixture, and further that is capable of reliably raising alarm or alert signals when such apparatus has retained or accumulated more than a pre-determined volume of water.

Summary

[009] The invention provides apparatuses for retaining water that has been separated from a fuel-water mixture by a fuel-water separator. [0010] In a first embodiment, the invention comprises a water retention apparatus for retention of water separated out of a fuel-water mixture by a fuel-water separator. The water retention apparatus comprises (i) a housing comprising at least one inlet, (ii) a water absorption receptacle comprising (a) a reservoir, and (b) at least one flexible fluid permeable barrier configured to permit passage of water from outside the water absorption receptacle into the reservoir, and (iii) a fluid passageway between the housing inlet and the fluid permeable barrier.

[0011] The water retention apparatus may further comprise one or more superabsorbent polymer materials are disposed within the reservoir. The fluid permeable barrier may be configured to prevent migration of the one or more superabsorbent polymer materials from the reservoir to outside the water absorption receptacle. The one or more superabsorbent polymer materials are in one or more of particulate, granule or bead form.

[0012] In an embodiment of the invention, the housing may be configured for effecting fixed or removable engagement between the housing inlet and an outlet of the fuel-water separator.

[0013] The water absorption receptacle may include (i) a reservoir opening for depositing one or more superabsorbent polymer materials within the reservoir, and (ii) a closure configured to close said reservoir opening.

[0014] In an embodiment of the invention, the fluid permeable barrier may comprise a woven fluid permeable barrier. The fluid permeable barrier may alternatively comprise a non-woven fluid permeable barrier. In an embodiment of the invention, the fluid permeable barrier may be affixed to a top end and a bottom end of the water absorption receptacle.

[0015] The engagement between the housing inlet and the outlet of the fuel-water separator may be such that the housing is positioned vertically below the fuel-water separator.

[0016] In an embodiment of the water retention apparatus, said apparatus includes a magnet disposed in the water absorption receptacle and at least one magnetic field sensitive switch disposed on the housing. The at least one magnetic field sensitive switch may comprise a reed switch. The at least one magnetic field sensitive switch may additionally be isolated from exposure to fluid from the fuel-water separator.

[0017] In an embodiment of the water retention apparatus, the position of the magnet may be fixed relative to a top end of the water absorption receptacle, and moveable relative to a bottom end of the water absorption receptacle.

[0018] The magnet and the at least one magnedc field sensitive switch may be respectively disposed in the water absorption receptacle and housing such that the magnetic field sensitive switch is triggered when the magnet moves a predefined distance away from the bottom end of the water absorption receptacle.

[0019] In an embodiment of the water retention apparatus, (i) the at least one magnetic field sensitive switch may include a first magnetic field sensitive switch and a second magnetic field sensitive switch, and (ii) each of the magnet and the first and second magnetic field sensitive switches may be disposed on or within the water retention apparatus such that (a) the first magnetic field sensitive switch is triggered when the magnet moves a first predefined distance away from a bottom end of the water absorption receptacle, and (b) the second magnetic field sensitive switch is triggered when the magnet moves a second predefined distance away from the bottom end of the water absorption receptacle.

[0020] The water absorption receptacle may include at least one support shaft disposed between a top end and a bottom end of said water absorption receptacle, wherein a bottom end of the support shaft abuts the bottom end of said water absorption receptacle. A top end of the support shaft may be located within a guide channel formed on the top end of said water absorption receptacle.

[0021] In an embodiment, at least one point or surface of the water absorption receptacle is immoveably affixed within the housing.

[0022] In another embodiment, said water retention apparatus may be in sealing engagement with a fuel-water separator, said fuel-water separator comprising (i) an inlet, (ii) at least one hydrophobic barrier that allows passage of fuel therethrough and onward to a fuel oudet, and (iii) a water outlet for water separated by the hydrophobic barrier.

[0023] The invention additionally provides a fuel-water separator comprising (i) an inlet, (ii) at least one hydrophobic barrier that allows passage of fuel therethrough and onward to a fuel outlet, and (iii) a water retention apparatus comprising (a) a housing comprising at least one inlet, (b) a water absorption receptacle comprising a reservoir and at least one flexible fluid permeable barrier configured to permit passage of water from outside the water absorption receptacle into the reservoir, and (c) a fluid passageway between the housing inlet and the fluid permeable barrier.

Brief Description of the Accompanying Drawings

[0024] Figure 1 illustrates a conventionally known fuel-water separator.

[0025] Figures 2 and 4 illustrate water retention apparatuses in accordance with the present invention.

[0026] Figures 3 and 5 illustrate water retention apparatuses in accordance with the teachings of the present invention — in engagement with corresponding fuel-water separators.

[0027] Figure 6 illustrates a water absorption receptacle corresponding to a water retention apparatus of the present invention.

[0028] Figures 7 and 8 illustrate external housings corresponding to water retention apparatuses of the present invention.

Detailed Description

[0029] The present invention provides a water retention apparatus for receiving water that has been separated from a fuel-water mixture by a fuel-water separator. The apparatus of the present invention prevents water droplets that have already been separated within the fuel-water separator from re-emulsifying with an incoming fuel-water mixture. The apparatus is further configured to reliably raise alarm or alert signals when a predetermined amount or volume of water has accumulated.

[0030] Figure 1 illustrates a cross-sectional view of a conventional fuel-water separator 1 . Fuel-water separator 1 comprises a housing 4, within which housing, components of the fuel-water separator may be disposed. Housing 4 is typically a cylindrical housing (or canister or bowl) arranged such that the longitudinal axis of the housing is substantially aligned with a vertical axis. In the embodiment illustrated in Figure 1 , housing 4 comprises top end 401 , bottom end 402 and sidewalls 403. Top end 401 is an open top end, while bottom end 402 is a closed bottom end. Housing 4 may be manufactured using any metal, hard plastic or composite rigid or semi-rigid material (for example, a glass reinforced polyamide).

[0031] Located at top end 401 of housing 4, are one or more components configured to effect sealing engagement between housing 4 and the fuel injection system. In the embodiment illustrated in Figure 1 , the one or more components located at top end 401 include anchor plate 5 and retainer plate 6 - which are welded together or otherwise engaged. Anchor plate 5 serves as a closure for top end 401 of housing 4, while retainer plate 6 enables sealing engagement of housing 4 with the engine / engine fuel supply system. In the illustrated embodiment, a gasket 10 may be interposed between retainer plate 6 and the fuel supply system to achieve sealing engagement with the fuel supply system.

[0032] Anchor plate 5 may be provided with one or more inlet orifices 7, 7' and at least one (and preferably only one) oudet orifice 8. Outlet orifice 8 may in a specific embodiment have one or more interface mechanisms 9 that enable sealing engagement between the fuel-water separator 1 and the engine / engine fuel supply system. Non-limiting examples of interface mechanisms 9 that enable sealing engagement may include screw-threads and / or snap-fit or twist-lock arrangements.

[0033] Disposed within housing 4 is at least one hydrophobic barrier media, and in an embodiment said barrier media comprises an annular or tubular hydrophobic filter 2. In the illustrated cross-secdonal view, the barrier media is an annular or tubular filter 2 disposed concentricaUy about a longitudinal axis of fuel-water separator 1. The illustrated filter 2 comprises outer surface 202, 202', inner surface 204, 204' and hydrophobic filter media 3 disposed between said outer surface and inner surface. The illustrated filter additionally includes an impermeable bottom surface 201 and a top surface 206. Inner surfaces 204, 204' and bottom and top surfaces 201 and 206 define a reservoir 205 within filter 2, which reservoir 205 houses fuel that has passed through hydrophobic filter media 3.

[0034] The hydrophobic filter media 3 may comprise a barrier media selected to allow fuel to pass through while preventing passage of water and / or particular matter.

[0035] The hydrophobic filter 2 may be arranged within housing 4 to create fluid passageways 701 , 701 ' - which permit the fuel-water mixture to enter housing 4 through inlet orifices 7, 7' and to come into contact with filter 2, thereby enabling separation of the fuel-water mixture into its respective fuel and water components. Separated fuel passes into reservoir 205 and outward through outlet orifice 8.

[0036] As a result of the differing specific gravities of water and fuel, water that is separated out of the fuel-water mixture setdes towards bottom end 402 of housing 4 and begins to accumulate in the space defined by bottom surface 201 of the filter, bottom end 402 of housing 4 and sidewalls 403 of housing 4. Bottom end 402 of housing 4 has drain valve 14 disposed therein. Drain valve 14 is provided with inlet end 1401 , outlet end 1402 and valve 1403. By manipulating valve 1403, water accumulated at the bottom end of housing 4 may be allowed to pass through drain valve 14 i.e. in from inlet end 1401 and out from outlet end 1402 - thereby draining the accumulated water from the fuel-water separator. In the illustrated embodiment, drain valve 14 may be affixed to housing 4 by one or more removable or non-removable fasteners 15. In the illustrated embodiment, fastener 15 is a crimp-nut.

[0037] Bottom end 402 of housing 4 is additionally provided with a sensor 13 - which sensor may be configured to generate a signal when the level of water accumulated at the bottom of housing 4 reaches a predetermined level. In an embodiment, responsive to sensor 13 indicating that the accumulated water has reached a predetermined level, drain valve 14 may be manipulated or actuated to allow the accumulated water to drain out of housing 4. [0038] In Figure 1 , resilient member 12 may be disposed between bottom end 402 of housing 4 and bottom surface 201 of filter 2, to resiliently urge filter 2 away from bottom end 402 of housing 4 and into sealing engagement with anchor plate 5. In the illustrated embodiment, resilient member 12 comprises a coil spring. Grommet 1 1 may be interposed between anchor plate 5 and top end 206 of filter 2 to enable sealing (preferably fluid tight) engagement between top end 206 of filter 2 and anchor plate 5, which reduces wear and tear.

[0039] Figure 2 illustrates an embodiment of a water retention apparatus 16 in accordance with the teachings of the present invention. Water retendon apparatus 16 comprises external housing 17, which comprises top end 1701 , bottom end 1702 and sidewalls 1703, 1703'. In an embodiment, top end 1701 , bottom end 1702 and sidewalls 1703, 1703' of external housing 17 define a substantially cylindrical or tubular inner region. External housing 17 may in an embodiment, comprise a rigid or semi rigid housing manufactured using metal, plastic or composite materials (for example, a glass reinforced polyamide). Figure 7 provides a detailed illustration of external housing 17.

[0040] Water absorption receptacle 18 is disposed within external housing 17. As shown in Figure 2, water absorption receptacle 18 is positioned within external housing 17 so that the longitudinal axis of water absorption receptacle 18 is substantially aligned with the longitudinal axis of external housing 17.

[0041] Figure 6 provides a detailed illustration of water absorption receptacle 18. Said water absorption receptacle 18 is a cylindrical / tubular (or substantially cylindrical / tubular) receptacle comprising a rigid or semi rigid top end 22a, a rigid or semi rigid bottom end 22b, and sidewalls 20, 20'. The tubular receptacle defines a reservoir 181. In an embodiment of the invention, sidewalls 20, 20' comprise a fluid permeable barrier- wherein the fluid permeable barrier is configured to permit passage of fuel and/or water from outside the water absorption receptacle into reservoir 181. The fluid permeable barrier may in an embodiment of the invention, comprise a flexible fabric barrier selected to enable passage of water and/ or fuel into reservoir 181 , while preventing migration of non-fluid materials (for example solid, particulate or granular materials) from reservoir 181 to outside of water absorption receptacle 18. In an embodiment of the invention, the fluid permeable barrier may comprise a woven or a non-woven fluid permeable fabric barrier. It has been surprisingly found that use of a non-woven fluid permeable fabric as a fluid permeable barrier presents particular improvements in maintaining water permeability despite exposure of the fluid permeable fabric to fuel droplets within the fuel-water mixture.

[0042] In an embodiment of the invention, top end 22a of water absorption receptacle 18 may include a removable closure 25, which can be removed for accessing reservoir 181 through a reservoir opening provided within top end 22a. The reservoir opening may be provided tor depositing materials within reservoir 181 , after which closure 25 may be used to close the reservoir opening and thereby seal within reservoir 181 , any solid, (including particulate or amorphous) materials that have been deposited therewithin. Closure 25 may be removably engaged with top end 22a by any number of fastening arrangements, including any of screw threads, snap-fit or twist-lock arrangements, screws, pins, clasps, rivets or other fasteners.

[0043] In an embodiment of the invention, water absorption receptacle 18 may be affixed to external housing 17 so as to prevent relative movement between water absorption receptacle 18 and external housing 17. In the embodiment illustrated in Figure 2, bottom end 22b of water absorption receptacle 18 is affixed to bottom end 1702 of external housing 17 by way of one or more fasteners. In the illustrated embodiment, bottom end 22b of water absorption receptacle 18 is provided with one or more channels or recesses 26 configured to accommodate one or more corresponding protrusions 38 (e.g. snap-fit or twist-lock protrusions) provided on bottom end 1702 of external housing 17. It would be immediately apparent that the fastening arrangements of Figure 2 are only illustrative.

[0044] Sidewalls 20, 20' of water absorption receptacle 18 may in an embodiment comprise flexible or deformable side walls. In an embodiment of the invention, the sidewalls 20, 20' may be formed from a fluid permeable fabric selected to permit passage of water from outside the water absorption receptacle into reservoir 181. In an embodiment, use of cotton or cotton based fabric to form sidewalls 20, 20' has been found to be particularly effective in achieving the desired properties for the sidewalls. In an embodiment of the invention, sidewalls 20, 20' may be formed by arranging one or more sheets of the fluid permeable medium (such as a fabric) in a tubular configuration, wherein a first end of the tube is fastened to (and optionally in fluid tight engagement with) top end 22a and the second end of the tube is fastened to (and optionally in fluid tight engagement with) bottom end 22b. In various embodiments of the invention, the fluid permeable medium may be fastened to top end 22a and bottom end 22b of water absorption receptacle using any one or more removable or permanent fasteners, including clips, screws, rivets, pins, staples, adhesive, wire ties or cable ties etc.

[0045] In an embodiment of the invention, the fluid permeable barrier used to form sidewalls 20, 20' of water absorption receptacle 18 may have any pore size smaller than the particle size(s) of the superabsorbent material disposed within the water absorpdon receptacle.

[0046] Reservoir 181 may have a plurality of super absorbent materials 19 (preferably superabsorbent polymer materials) disposed therein.

[0047] For the purposes of the invention, "superabsorbent" material shall be understood as a water-swellable, water-insoluble, organic material capable of absorbing water in several multiples of its own weight (preferably upto and over 300 times its own weight). A "superabsorbent polymer" is a crosslinked polymer which is capable of absorbing large amounts of water, with a corresponding swelling and formation of hydrogels, and which is also capable of retaining the absorbed water. Superabsorbent polymers for the purposes of the present invendon shall include all commercially available superabsorbent polymers based on cross-linked polyacrylic acids or starch-acrylic acid graft polymers.

[0048] When water droplets pass into reservoir 181 , such droplets come into contact with the superabsorbent materials 19. These superabsorbent materials absorb the water droplets, swell up and retain the water droplets therewithin - thereby preventing such water droplets from passing back out of reservoir 181. In an embodiment of the invendon, the superabsorbent materials may comprise superabsorbent polymer materials. In a more specific embodiment, the superabsorbent materials disposed within reservoir 181 may be in any one or more of particulate, powdered, granule or bead form.

[0049] The flexible or deformable fluid permeable barrier sidewalls 20, 20' of water absorption receptacle 18, enable top end 22a and bottom end 22b of water absorpdon receptacle 18 to be moved towards each other or moved away from each other. For the purposes of the present invention, when said top end 22a and bottom end 22b are moved towards each other, the water absorption receptacle 18 is understood to be moving from an expanded configuration to a compressed configuration. Conversely, when said top end 22a and bottom end 22b move away from each other, the water absorption receptacle 18 is understood to be moving from a compressed configuradon to an expanded configuradon.

[0050] Stated differendy, (i) when the distance between top end 22a and bottom end 22b of water absorpdon receptacle 18 is less than the maximum possible distance permitted by the length of flexible or deformable sidewalls 20, 20', the water absorpdon receptacle 18 may be understood as being in a compressed configuradon and (ii) when the distance between top end 22a and bottom end 22b of water absorption receptacle 18 is the maximum possible distance permitted by the length of flexible or deformable sidewalls 20, 20', the water absorpdon receptacle 18 may be understood as being in an expanded configuradon.

[0051] When water absorpdon receptacle 18 is initially filled with superabsorbent materials 19, it may be placed within external housing 17 in a compressed configuradon. During operadon, as water droplets enter reservoir 181 and are absorbed by the superabsorbent materials 19, the volume of saturated superabsorbent materials 19 progressively increases, which increase in volume eventually begins to push top end 22a away from bottom end 22b - thereby causing water absorpdon receptacle 18 to move from a compressed configuradon towards an expanded configuradon.

[0052] As illustrated in Figure 3, the water retendon apparatus 16 of Figure 2 may be configured to be posidoned vertically beneath a fuel-water separator 45 (of the same or similar type as has been previously illustrated and discussed in connecdon with Figure 1). By virtue of being posidoned beneath fuel water separator 45, water accumuladng towards the bottom end of said fuel water separator 45 passes from fuel water separator 45 into water retendon apparatus 16, preferably under flow induced by gravity.

[0053] Referring again to Figure 2, water absorpdon receptacle 18 may be disposed within external housing 17 in a way that a fluid passageway is created between sidewalls 1703 of external housing 17 and sidewalls 20, 20' of water absorption receptacle 18. Water droplets separated out of the fuel-water mixture in fuel water separator 45 pass into the water retention apparatus 16 positioned directly below it (i.e. through top end 1701 and into the fluid passageway between sidewalls 1703 and sidewalls 20, 20'). The water droplets in this fluid passageway come into contact with sidewalls 20, 20' and pass through said sidewalls 20, 20' into reservoir 181 — whereinafter said water droplets are absorbed by the superabsorbent materials disposed within reservoir 181 and thereby are prevented from re-emulsifying with the fuel-water mixture and recirculating within the fuel-water separator. Additionally, the flexible fabric used for constructing the flexible fluid permeable sidewalls 20, 20' prevent saturated as well as unsaturated superabsorbent materials 19 that are disposed within reservoir 181 from migrating from inside reservoir 181 to outside of said reservoir 181 and / or outside of water absorption receptacle 18.

[0054] Water absorption receptacle 18 may additionally include at least one (and preferably 3 or more) rigid support shaft 24 having top end 24a and bottom end 24b. Each support shaft 24 is configured and affixed within water absorption receptacle 18 so as to ensure that top end 22a and bottom end 22b of water absorption receptacle 18 remain positioned substantially parallel to each other. This arrangement ensures that even as water absorption receptacle 18 moves from a compressed configuration to an expanded configuration or vice versa, top end 22a and bottom end 22b remain parallel to each other.

[0055] In an embodiment of the invention, water absorption receptacle 18 may comprise three support shafts 24 positioned in a triangular configuration within reservoir 181.

[0056] In an embodiment of the invention, each support shaft 24 is configured such that a bottom end 24b of the support shaft 24 abuts bottom end 22b of water absorption receptacle 18. In an embodiment of the invention bottom end 24b of support shaft 24 is removably or permanently affixed to bottom end 22b of water absorption receptacle 18. In another embodiment of the invention, bottom end 24b of support shaft 24 may be seated within a recess, channel or seat 24d formed on bottom end 22b of water absorption receptacle 18.

[0057] Top end 24a of support shaft 24 may likewise be seated within a seat 24c formed on top end 22a of water absorption receptacle 18 - preferably without any other form of engagement between support shaft 24 and top end 22a of water absorption receptacle 18. By ensuring that seat 24c is sufficiently deep, top end 22a of water absorption receptacle may be moved away from bottom end 22b without displacing support shaft 24 from said seat 24c. This arrangement permits top end 22a and bottom end 22b to be moved relative to each other, while ensuring that support shaft 24 is retained within respective top and bottom seats 24c and 24d - and thereby ensuring that top end 22a and bottom end 22b remain parallel to each other.

[0058] In another embodiment of the invention, each support shaft 24 may comprise a telescoping shaft with top and bottom ends 24a and 24b respectively affixed to top end 22a and bottom end 22b of the water absorption receptacle 18. The telescoping arrangement ensures that top end 22a and bottom end 22b are moveable relative to each other, while ensuring that they remain parallel to each other at all times.

[0059] In the embodiment illustrated in Figure 2, the invention additionally comprises a mechanism for generating a signal when the water retained by the superabsorbent material within the water absorption receptacle 18 has reached a predetermined volume— thereby indicating that the saturated superabsorbent materials 19 within water absorption receptacle 18 needs to removed and replaced with fresh unsaturated superabsorbent materials, or that the water absorption receptacle 18 needs to be replaced.

[0060] In the embodiment of the invention illustrated in Figure 2, the mechanism for generating an alert signal includes a first component disposed on water absorption receptacle 18 and a second component disposed within external housing 17. The first component disposed on water absorption receptacle 18 comprises a magnet 28 affixed to a rigid support member 27 - which rigid support member 27 is in turn affixed to top end 22a of water absorption receptacle 18. This arrangement ensures that the distance between magnet 28 and top end 22a of water absorption receptacle 18 remains constant - regardless of whether water absorption receptacle 18 is in a compressed configuration or in an expanded configuration. At the same time, this arrangement ensures that magnet 28 is moveable relative to bottom end 22b of water absorption receptacle 18 - which relative movement occurs as water absorption receptacle 18 moves from a compressed configuration towards an expanded configuration. [0061] The second component of the mechanism for generating a signal comprises at least one magnetic field sensitive switch 30 (for example, a reed switch) positioned on external housing 17. Said magnetic field sensitive switch 30 may be configured to generate an alert signal, alarm signal or other signal in response to being influenced by the magnetic field generated by magnet 28. It would be understood that magnetic field sensitive switch 30 would generate the necessary signal when the distance separating magnet 28 from magnetic field sensitive switch 30 is a distance less than the maximum distance within which magnetic field sensitive switch 30 can detect the magnetic field generated by magnet 28.

[0062] The combination of one or more of (i) position of the water absorption receptacle 18 on external housing 17 (ii) position of magnet 28 relative to top end 22a of water absorption receptacle 18, and (iii) position of magnetic field sensitive switch 30 on external housing 17, may be selected such that, the magnetic field sensitive switch 30 is triggered to generate a signal when magnet 28 moves a predetermined distance away from bottom end 22b of water absorption receptacle 18.

[0063] Referring to the embodiment illustrated in Figure 2, it would be understood that in operation, superabsorbent materials 19 within reservoir 181 absorb water and increase in volume, and said expanding superabsorbent materials 19 force top end 22a of water absorption receptacle 18 (and correspondingly the magnet 28 that is positioned at a fixed distance relative to top end 22a) to move away from bottom end 22b. As a consequence of water absorption receptacle 18 being immoveably affixed within external housing 22a, top end 22a (and magnet 28) is are also forced to move relative to bottom end 1702 and sidewalls 1703 of external housing 17. Accordingly, in the embodiment illustrated in Figure 2, as water absorption receptacle 18 moves from a compressed configuration to an expanded configuration, magnet 28 moves closer to magnetic field sensitive switch 30 until it is sufficiently close to trigger magnetic field sensitive switch 30 to generate an alarm or alert signal. By appropriate positioning of magnet 28 and magnetic field sensitive switch 30, the present invention can be configured to generate alerts in response to absorption of a predetermined volume of water within water absorption receptacle 18.

[0064] It would additionally be understood that more than one magnetic field sensitive switch may be provided on external housing 17 so that switch is triggered at a different position of magnet 28 relative to external housing 17— thereby ensuring that multiple alert signals can be generated corresponding to various positions of magnet 28 i.e. corresponding to various different volumes of water absorbed by the superabsorbent materials in water absorption receptacle 18.

[0065] In an embodiment of the invention, at least first and second magnetic field sensitive switches may be provided on external housing 17.

[0066] Each of the magnet and the first and second magnetic field sensitive switches may be disposed on external housing 17 such that (i) the first magnetic field sensitive switch is triggered when the magnet moves a first predefined distance away from a bottom end 22b of the water absorpuon receptacle 18, and (ii) the second magnetic field sensitive switch is triggered when the magnet moves a second predefined distance away from the bottom end 22b of the water absorption receptacle 18.

[0067] In an embodiment of the invention, rigid support member 27 may be press fitted into a slot in top end 22a of water absorption receptacle 18.

[0068] In an embodiment of the invention magnetic field sensitive switch 30 may comprise a potted, reed-type contact switch 30 that is disposed within a rigid holder 29 (see Figures 2, 3 and 7). Said rigid holder may in an embodiment be isolated from any fluid passageways, thereby ensuring that magnetic field sensitive switch 30 is protected from exposure to the fuel-water mixture. Holder 29 may be press-fitted against counter pressure from a bellow-shaped gasket 31 held in a hollow, 'C'-shaped protrusion 32 (see Figures 2, 3 and 7), into a slotted member 33 extending from die outer periphery of external housing 17.

[0069] External housing 17 may additionally be provided with one or more fastening features that enable water retention apparatus 16 to be positioned vertically beneath a fuel- water separator 45 (in the manner illustrated in Figure 3).

[0070] Referring to the embodiment illustrated in Figures 2 and 7, a top end of external housing 17 may be provided with suitable screw threads 34 (or any other fastening surfaces or fasteners) to engage with corresponding screw threads 51 (or other fastening surfaces or fasteners) provided at a bottom end of the fuel water separator 45 (see Figure 3). In various embodiments, screw threads 34 may be provided on one or both of inner and outer peripheries of a top end of external housing 17. In the embodiment illustrated in Figures 2 and 3, external housing 17 is additionally provided with one or more fluid passageways 35 which allow any excess fluid that drips or leaks from the fuel-water separator through the fastening mechanisms and into the external housing 17, to pass into fluid passageway 1701. Additionally, or alternatively, external housing 17 may be provided with one or more drain channels to allow fluid from such drips or leaks to drain out of external housing 17.

[0071] In the embodiment illustrated in Figures 2 and 3, the top end of external housing 17 may additionally be provided with a groove 36 to seat a gasket 37 to ensure fluid tight engagement between fuel-water separator 45 and external housing 17.

[0072] Referring specifically to Figure 3, the illustrated embodiment comprises water retention apparatus 16 positioned vertically beneath fuel- water separator 45. Water accumulating towards the bottom end of said fuel water separator 45 passes from fuel water separator 45 into water retention apparatus 16, preferably under flow induced by gravity. In the illustrated embodiment, fuel-water separator 45 comprises hydrophobic barrier media 46 comprising an annular or tubular hydrophobic filter 3, assembled within a housing 47, whose top end is provided with an anchor plate 48 affixed to a retainer plate 49.

[0073] A resilient member or spring 52 is positioned between bottom end 50 of housing 47 and a bottom end of filter 3 - so as to urge filter 3 away from bottom end 50 of housing 47. Bottom end 50 of housing 47 additionally is provided with one or more fasteners (such as screw threads 51) to enable fluid tight engagement with corresponding fasteners (such as screw threads 34) on external housing 17 of water retention apparatus 16. It will additionally be observed that bottom end 50 of housing 47 may be provided with one or more orifices 50a which allow water accumulating at bottom end 50 of fuel water separator 45 to flow into water retendon apparatus 16.

[0074] Figure 4 illustrates an alternative embodiment of a water retention apparatus 39 in accordance with the teachings of the present invention. Water retention apparatus 39 comprises external housing 40 having a substantially tubular inner region. External housing 40 may in an embodiment, comprise a rigid or semi rigid housing manufactured using metal, plastic or composite materials (for example, a glass reinforced polyamide). Figure 8 provides a detailed illustration of external housing 40.

[0075] As in the case of Figures 2 and 7, external housing 40 may include a potted, reed- type contact switch 30 that is disposed in a rigid holder 29. Holder 29 may be press-fitted against counter pressure from a bellow-shaped gasket 31 held in a hollow, 'C'-shaped protrusion 41 , into a slotted member 42 extending from the outer periphery of external housing 40.

[0076] Water absorption receptacle 18 may be disposed within external housing 40 and is configured to operate substantially in the same manner as when disposed within external housing 17 of Figures 2 and 7.

[0077] A significant difference between the water retention apparatus 39 of Figure 4 and the water retention apparatus 16 of Figure 2 is in terms of the interface between said water retention apparatuses and a corresponding fuel-water separator positioned direcdy above said water retention apparatus.

[0078] As illustrated in Figures 2 and 3, the external housing 17 of water-retention apparatus 16 of Figure 2 is configured to engage with a specifically modified fuel water separator 45. The modifications to fuel water separator 45 comprise replacement of a closed bottom end of said fuel water separator with a specifically designed or molded bottom end 50 - which bottom end 50 is dimensioned and configured to enable fluid tight engagement with fasteners 34 at a top end of external housing 17, and which also includes orifices 50a which allow water accumulating at bottom end 50 of the fuel-water separator 45 to flow into water retention apparatus 16.

[0079] On the other hand, as illustrated in Figures 4 and 5, the external housing 40 of water-retention apparatus 39 (of Figure 4) is configured to engage with a fuel water separator 53 having a different configuration (see Figure 5).

[0080] Referring specifically to Figure 5, the illustrated embodiment comprises water retention apparatus 39 positioned vertically beneath fuel-water separator 53. Water accumulating towards the bottom end of said fuel water separator 53 passes from fuel water separator 53 into water retention apparatus 39, preferably under flow induced by gravity. In the illustrated embodiment, fuel-water separator 53 comprises hydrophobic barrier media 54 comprising an annular or tubular hydrophobic filter 3, assembled within a housing 55, whose top end is provided with an anchor plate 56 affixed to a retainer plate 57.

[0081] A resilient member or spring 59 is posiuoned between a bottom end of housing 55 and a bottom end of filter 3 - so as to urge filter 3 away from the bottom end of housing 55. The bottom end of housing 55 additionally is provided with a drainage orifice 50b to enable drainage of water accumulating at the bottom of housing 55. Conventionally such orifices are sized to enable engagement with a drain valve (as in the case of the fuel-water separator illustrated in Figure 1).

[0082] A drain valve may accordingly be removed from housing 55, and drainage orifice 50b may be provided with one or more fasteners (such as screw threads 58) to enable fluid tight engagement with corresponding fasteners (such as screw threads 43) on external housing 40 of water retention apparatus 39 (of Figure 4). Alternatively fasteners on external housing 40 of water retention apparatus 39 may be mated with a drain valve orifice 50b provided on housing 55 of fuel-water separator 53. Said orifice 50b thereafter allows water accumulating at the bottom end of fuel water separator 53 to flow into water retention apparatus 39. It would be understood that using orifice 50b (which is sized for or intended for use with a drainage valve) as an interface for sealing engagement with the water retention apparatus of the present invention obviates the need for periodic drainage of the fuel-water separator.

[0083] In an embodiment, the invention comprises an improved fuel-water separator comprising, an inlet, at least one hydrophobic barrier that allows passage of fuel therethrough and onward to a fuel oudet, and a water retention apparatus comprising any of the embodiments of water retention apparatuses described in detail hereinabove. In one embodiment, said water retention apparatus comprises (i) a housing comprising at least one inlet, (ii) a water absorption receptacle comprising (a) a reservoir, and (b) at least one flexible fluid permeable barrier configured to permit passage of water from outside the water absorption receptacle into the reservoir, and (iii) a fluid passageway between the housing inlet and the fluid permeable barrier. [0084] It would be understood that the present invention presents multiple advantages over arrangements known in the prior art. First, by using a flexible fluid permeable barrier within water retention receptacle 18 to allow passage of water into reservoir 181 and simultaneously prevent migration of superabsorbent materials disposed within reservoir 181 to outside of water retention receptacle 18, the water retention apparatuses of the present invention prevents water droplets that have already been separated, from re- emulsifying with an incoming fuel-water mixture. Additionally, by providing a sensing mechanism where the electronic sensors (e.g. the magnetic field sensitive switches) are isolated from and do not come into contact with the fuel-water mixture and particulate matter, the invention ensures longevity of the sensing and alert mechanisms. Lasdy, by selecting an appropriate size of a water retention apparatus and an appropriate quantity of superabsorbent materials for storage within the water absorption receptacle, the invention significantly reduces(and can even do away entirely) the need for removing accumulated water that has been separated out from a fuel supply by a fuel-water separator.

[0085] While exemplary embodiments of the present invention are described and illustrated herein, it will be appreciated that they are merely illustrative. It will be understood by those skilled in the art that various modifications in form and detail may be made therein without departing from or offending the spirit and scope of the invention as defined by the appended claims.