CA1196237A - By-pass for fuel-water separator - Google Patents

Abstract

Abstract of the Disclosure A fuel-water separator having a plurality of spaces is provided with a by-pass. The by-pass includes an inlet which has an opening through which liquid can pass.
The opening includes a rim for serving as a seat for a stopper. The stopper is sized to be engageable with the seat, and movable between an engaged position and a disengaged position. An element is provided for biasing the stopper into engagement with the seat. A passageway is provided for conducting fuel from the inlet.

Description

This invention relates to fuel line devices, and more particularly to a fuel-water separator which further includes a by-pass to transport fuel past all or a portion of the device, in response to an obstruction therein.
Fuel for internal combustion engines is often con--taminated with impurities such as particulate matter and water which becomes entrained in the fuel. The presence of these impurities can deleteriously affect engine performance. The problems associated with entrained impurities are especially acute with diesel engines, as diesel fuel tends to be more highly contaminated than gasoline.
To solve the above-mentioned problem, it is often advisable to install filters and fuel-water separators in the fuel line to trap entrained particles and separate entrained water from the fuel, respectively.
In fuel-water separators, it is often advisable to employ filters, surface tension discriminators, or a series thereof which are capable of separating line water particles which become entrained in the fuel, and which are not normally fully removed by centrifugal or gravitational separation. A
fuel-wa-ter separator which employs surface tension discriminators is disclosed in our United States Patent No. 4,384,962.
One of the problems associated with the use of filters and fuel-wa-ter separators is that, in cold weather, diesel fuel has a tendency to become frozen in portions of the filters and separator. Frozen fuel, when used in this application~ encom-passes fuel oil, water or both which, because of lowered temper-ature, becomes too viscous to pass ,._ . .~
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through a filter or separator. The problems associated with fro~en fuel are therefore not necessarily confined to situations wherein either the fuel oil, water or or both are ii a crystalline state. Further, the diesel fuel which flows through the filter or separator often contains particulant contaminantst and the filter separator can become clo~ged.
The freezing and clogging phenomena are generally more acute at the portions fo the filters or separators where strainers membranes, or filtering elements are employed through which 10. the fuel passes than in the tubing of the fuel line, or the circu'arly or upwardly and downwardly directed paths of a fuel-water separator. One example of a portion in a separator prone to clogging and freezing is the surface tension discriminators.
Should fuel be unable to move through the fuel path, either because of clogging or freezing, the en~ine to which the fuel is ultimately fed will not be able to runO A
decrease in fuel flow caused by a partially clogged or partially frozen fuel path can severely limit the performance 20. of the engine.
In cases w7herein movement of fuel throug7n the separator is impeded due to the fuel freezing in the separator, it is helpful to be able to have the engine running, so that the heat radiated by the running engine can aid in thawing the fuel frozen within the separator.
In accordance with the present invention, in a fuel delivery path having a portion through which the flow of fuel can become restricted, a by-pass means is provided for by-passing the fuel past the restrictive portion. The 30. by-pass means includes an inlet mean~ disposed in the path.

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The inlet means includes an opening~ A passageway is provided for conducting fuel from the inlet. A
pressure-responsive control element is provided for controlling the flow of fuel between the inlet and the passageway.
One feature of the instant invention is that a means is provided for partially by-passing a fuel-water separator. This feature has the advantage of allowing the car to run if the separator is clogged or frozen. Furthex, 10. if the separator is partially clogged or partially frozen, the by-pass will allow the engine to receive a sufficient amount of fuel to continue running.
Another feature of the instant invention is that the by-pass is biased to a closed position. During normal operations of the car, this feature ens~res that the fuel will travel through the full separator and not through the by-pass. This ensures tha~ the fuel which enters the cylinders will be substantially water-~ree.
It is also a feature of a preferred embodiment of 20. this invention that the movement of a stopper is restricted to movement which is substantially along the same axis as the axial length of a spring-biasing means. This arrangement ensures that the stopper will always be properly positioned to take full advantage of the force exerted by the biasing means on the stopper.
A ~urther feature of the instan~ invention is that the by-pass only by-passes that part of the separator where the freezing and clogging problems are most acute. This feature has the advantage of ensuring that fuel which passes 30. through the by-pass has undergone at least a partial 62~
separation, thereby removing at least some of the water from the fuel before allowing the fuel to enter the fuel njectors and cylinders. Further, the portions of the separator which t~e by-pass valve does not by-pass, e.g., the centrifugal separation section, are sections which are less likely to become clogged or frozen.
Another feature of the instant invention is khat a passageway is provided for the by-pass which by-passes the fuel directly into the fuel line. The advantage of this lQ. feature is that ~he by-pass can respond to diferences in pressure between the upstream side and the downstream side of the by-pass. Thus, on vehicles wherein a separator is placed in the fuel line upstream of the fuel pump, the vacuum created by the action of the fuel pump on the fuel line will cause the by-pass to operl. ~ormally, this vacuum will only be sufficient to open the by-pass valve durins times when fuel is unable to pass through the separator due to clogging or freezing. Conversely, on vehicles wherein the separator is placed downstream in the fuel line from the fuel pump, the 20. pressure created by the fuel pump on the upstream side of the by-pass valve will cause the by-pass valve to open, if fuel is unable to pass through the separator.
These and other features of this invention and their inherent advantages will become apparent to those skilled in the art from the ollowing description of preferred embodiments and the accompanying drawings illustrating the best mode of carryinq out the invention, wherein:
Fig. 1 is a cross-sectional view of a fuel-water separator embodying the invention;

2~7 Fig. 2 is an enlarged, partial, cross-sectional view of the invention with the stopper in the open position;
and Fig. 3 is a top cross-sectional view of the invention, taken along lines 3-3 of Fig. 1~
Referring to the drawings, Fig. 1 shows the fuel-water separator 8 of the present invention, comprising an upright cylindrical housing 10 having a lower can or can portion 12 and an upper cover or cover portion 14 joined lG. together to provide a seal between the cover 14 and can 12.
Fuel enters the separator 8 through a port 16 and exits through a port 18.
A central opening 20 is formed at the bottom of the can portion 12 of the housing 10 to provide a drainage port for water accumulated at the bottom of the can 12. A petcock 22 is threaded into a threaded tube 24 brazed into the central opening ~0. By opening and closing petcock 22, drainage of the water from can 12 can ~e controlled.
Inside the housing 10 is a circular plate 26 having 20. a plurality of holes or openings 28. The diameter of the plate 26 is less than the diameter of the can 12 so that a circumferential space 30 is provided between the outer peripheral edge of the plate 26 and the can 12 for channeling water to the bottom of the can 12.
The plate 26 is provided with an opening 32 concentric with a downwardly extending sleeve 34. The lower edge of the sleeve 34 rests upon a retainer for a ball 36.
This ball 36 can move upwardly and downwardly in the retainer in a space defined by peripherally spaced-apart, vertically extending legs 38. Legs 38 define a plurality of drainage ~9~z;~
opening spaces therebetween. The ball 36 rests upon a seat formed at the bottom central opening 20 of the can 12.
A drainage tube 40 extends downwardly through the opening 32 in sleeve 34. The lower end of tube 40 provides an upper stop for the ball 36. The lower end includes a plurality of reliefs or notches 42 which provide drainage relief and which prevent the ball 36 from sealing off the bottom of the tube 40.
Mounted on or connected to the top of the plate 26 10. is a semicircular fuel passageway or raceway 44 which may have a cross-sectional inverted U-shape. This passageway 44 is designed to apply a centrifugal force to the fuel-water mixture passing therethrough. The fuel enters the passageway 44 at point 45 and moves clockwise through the passageway 44.
About the last one-third o the radially outer peripheral wall of the passageway 44 is provided with openings 46. The fuel-water mixture continues to move through the passageway 44 and exits through the end (not shown) of the passageway.
The liquid mixture passes through the openings 48 and moves 20. into a first space 50 above the cover 52. Separated water, which is still entrained in the liquid mixture after the centrifugal action, may fall by gravity along the downwardly sloping upper wall ~4 of the cover 52 and into the bottom o the can 12.
The first space 50 into which the liquid moves after leaving the centrifugal section 56 is illustratively defined by the uppex wall 54 of the cover 52, the conical flange portion of the tube 40, as well as by the bottom and side of an outer cup 58. The space 50 is alsol ~s shown in Fig~ 1, 30. defined by the inner surface of the can 12. It will be seen ~:~9~
that the conical flange provides a seat or support for the rather shallow conically shaped bottom of the outer cup 58.
The liquid in space 50 flows through a plurality of openings 60 into second space 62. A surface tension separator 64 is generally cylindrical and has an outer cylindrical wall, a lower end, and an upper end which form an interior 65 of the separator out of which extends exit tube 18. Exit tube 18 conducts separated fuel from the fuel-water separator 8.
10. An inner cup 66 is provided over the surface tension separator 64. This inner cup 66 defines a third space 68. The third space 68 also has a plurality of openinss 70 peripherally spaced about its upper edge for movement of the liquid mixture into the inner cup 6S, and a plurality of openings 72 peripherally spaced about its bottom for movement of water toward the bottom of can 12. The shallow conical bottom of the cup 66 is provided with a concentric opening 74 forming an upper seat for a ball 76 captured in a ball retainer defined by a plurality of 20. peripherally spaced~apart fingers 78 extending upwardly from the flange portion of the drainage tube 40. The drainage tube 40 is formed to provide a lower seat 80 for the ball 76 with the seat 80 being below and concentric with the upper seat 74. The ball 76, therefore, can move between the upper seat 74 and the lower seat 80 in the vertical space defined by the fingers 78.
Mounted concentrically about the inner cup 66 is a support cage 82 providing a plurality of peripherally spaced-apart, axially extending openings 84. The retainer 30. ring 86 has a plurality of peripherally spaced-apart openings 88 in the bottom web portion of the channel. The radially inner peripheral edge of ring 86 engages the outer peripheral surface of the inner cup 66 just below the openings 72 in the cup 66. A sleeve 90 of untreated fiberglass media i5 placed on the cage 82. Another surface tension separator 92 is provided around the outer periphery of the sleeve 90~
In the illustrative embodiment, the surface tension separators 64, 92 separate fine water particles 10. having a diameter of about 130-140 microns from the liquid mixture. These are water particles which are too small to be separated by centrifugal or gravity action. The separator media may be either a monoilament polyester fiber woven into a cloth having a pore size of about 130-140 microns or a monofilament Teflo ~ screen having a similar pore size with approximately 100 fibers both horizontally and vertically per inch, i.e., 10,000 fibers/square inch. Each o these separator media will separate water particles of the diameter indicated and pass fuel in response to widely 20. varying surface tensions between the two liquids. The separated water will flow down the outer surface of the separator media.
Further, in the illustrative embodiment, sleeve gO
is a mat of untreated random length fiberglass fibers, comercially referred to as Class 5A fiberglass.
During cold weather, it is foreseeable that diesel fuel will freeze within the separator, thus impeding the fuel flow through the separator. Further, due to the particulant matter contained in diesel fuel, it is not unlikely that the 30. separator 8 will become clogged after long usage. If either ;Z37 clogging or freezing do occur, they are most likely to occur at or near surface tension discriminator 92, thereby either impeding or preventing the flow of fuel through the surface tension discriminator 92. If fuel is unable to travel through the separator 8, no fuel will be able to get from the fuel storage tank to the engine, thereby preventing the engine from running. To alleviate this problem, and to provide fuel to the engine during times when the separator 8 may be either clogged or frozen, by-pass valve 94 is 10. provided.
By-pass valve 94 includes an inlet 96 which is disposed above space 62. The placement of inlet 96 over space 62 ensures that fuel which is by-passed around the inner part of the separator 8 will at least undergo a partial separation in the centrifugal section 56 of the separator. Inlet 96 is ormed by floor 98 cylindrical wall 100 and ceiling 102. Floor 98 includes an opening 104, through which the fuel enters the inlet 96 from space 62.
Preferably, opening 104 includes a circumferential rim 106 20. which serves as a seat for stopper 108. Stopper 108 is sized to seat against circumferential rim 106. During the normal operation of the separator, i.e., times when the separator is neither clogged nor frozen, stopper 108 is biased to engage seat 106 by spring 110. Spring 110 is chosen to have a length and spring force constant so as to normally bias stopper 108 against seat 106, but to compress in response to either a decrease in pressure in outlet 18 or an increase in pressure in spaces 50, 62. In vehicles wherein the separator is placed in the fuel line upstream of the fuel pumpr the stopper 108 will become unseated in response to a decrease in ~1~6Z~7 pressure in the exit tube 18 caused by the partial vacuum created from the fuel pump drawing air through the exit tube 18.
In cars wherein the separator 8 is placed downstream of the fuel pump, it is envisioned that the stopper 108 will be in spaces 50, 62. Emanating from a portion of cylindrical wall 100 is a passageway 112 which conducts fuel from inlet 96 to exit tube 18. In so conducting the fuel from inlet 96 to exit tube 18, passageway 112 by-passes the inner portion of the separator which, because it contains surface tension 10. discriminator 54, is also likely to become clogged or frozen.
Leg 114 is partially disposed across the entrance to passageway 112 in order to restrict the movement of ball 108 to movement in a substantially vertical direction.
Further, leg 114 also prevents ball 108 from entering into passageway 112 and thereby impeding the flow of fuel through passageway 112.
Referring now to Fig. 1, the stopper 108 is seen in its closed position. The stopper 108 assumes its position during the normal functioning of the separator, and remains 20. seated upon rim 106 except during such times as when the separator 8 is either clogged or frozen. Spring 110 is selected to normally bias stopper 108 against rim 106.
Referring now to Fig. 2, an enlarged cross-sectional view of the by-pass valve 94 is shown wherein the spring 110 has compressed, causing the stopper to become unseated from rim lOG. In this position/ fuel can flow through opening 104 into inlet 96, and through passageway 112 into exit tube 18, and eventually to the engine.
Referring now to Fig. 3, a top cross-sectional view 30, of the separator 8 is sllown. In the embodiment of Fig. 3, the ~6~7 separator is shown containing a plurality of by-pass valves 94. The use of a plurality of by-pass valves ensures that fuel will be more efficiently by~passed from the clogged area of the separator. Further, should the separator 8 clog or freeze in the area of spaces 50, 62 adjacent to the opening 104 of one of the by-pass valves 94~ fuel will still be able to be routed through another of the by-pass valves, thus ensuring a flow of fuel to the engine.
Although the invention has been described in detail 10. with reference to certain preferred embodiments and specific examples, ~ariations and modifications exist within the scope and spirit of the invention as described and as defined in the following claims.

Claims (11)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a fuel delivery path having a portion through which the flow of fuel can become restricted, a by-pass means for by-passing the fuel past the restrictive portion, the by-pass means comprising an inlet means disposed in the path, the inlet having an opening, a passageway for conducting fuel from the inlet, and a pressure-responsive control element for controlling the flow of fuel between the inlet and the passageway.

2. The invention of claim 1 wherein the control element comprises a stopper sized to be engageable with the opening and movable between a position engaged with the opening and a position disengaged from the opening, and an element for biasing the stopper into engagement wiht the opening.

3. The invention of claim 2 wherein the opening includes a substantially circular rim for serving as a seat for the stopper, the stopper is substantially spherical in shape, and the biasing element comprises an expansion-biased spring for biasing the stopper into engagement with the seat under normal conditions, the spring being compressible in response to changes in fuel pressure to allow the stopper to become disengaged from the seat.

4. The invention of claim 2, further comprising a means for allowing movement of the stopper in one direction while restricting movement of the stopper in a direction substantially perpendicular to the first direction, and wherein the passageway conducts fuel a portion of the path downstream of the restricted portion.

5. A fuel water separator comprising a container having entry and exit ports and means inside said container defining a progression of spaces through which the fuel moves from the entry port to the exit port, said space-defining means being disposed in said container to direct the fuel through a series of downwardly and upwardly directed paths as it moves through said spaces to cause the higher density water to move downwardly while the lower density fuel moves upwardly, said space-defining means further defining openings in the lower portions of said spaces through which the separated water drains downwardly, and a pressure-responsive by-pass means for directing fuel from one of the spaces past one of the space-defining means when the movement of fuel through the separator is impeded.

6. The invention of claim 5 wherein the by-pass means comprises an inlet means disposed in one of the spaces, the inlet having an opening, a stopper sized to be engageable into the opening, and movable between a position in engagement with the opening and a position disengaged with the opening, an element for biasing the stopper into engagement with the opening, a means for allowing movement of the stopper in a first direction, while restricting movement of the stopper in a second direction substantially perpendicular to the first direction, and a passageway for conducting fuel from the inlet.

7. The invention of claim 6 wherein the opening includes a substantially circular rim for serving as a seat for the stopper, the stopper is substantially spherical in shape, the biasing element comprises an expansion-biased spring for biasing the stopper into engagement with the seat under normal operating conditions, the spring being compressible in response to changes in fuel pressure to allow the stopper to become disengaged from the seat, and wherein the passageway conducts fuel to the exit port.

8. A fuel-water separator comprising an upright container having an entry port and an exit port, an outer cup and an inner cup disposed in said container to define generally concentric first, second, and third spaces through which the fuel progressively flows between the entry port and exit port, said container and said outer cup defining said first space for receiving fuel from said entry port, said outer and inner cup defining therebetween said second space for receiving fuel from said first space, and said inner cup defining therein said third space for receiving fuel from said second space, said container and cups defining openings providing communication between said spaces adjacent the upper portions of said cups such that the fuel moves upwardly to move between said spaces, said inner cup having an opening at its bottom for draining separated water downwardly, said outer cup having an opening at its bottom for draining separated water downwardly said container having an opening at its bottom for draining separated water downwardly and out of the container, and a pressure-responsive by-pass means for conducting fuel from one of the spaces when the flow of fuel through the separator is impeded.

9. The invention of claim 8 wherein the by-pass means comprises an inlet means disposed in one of the spaces, the inlet having an opening, the opening having a rim for serving as a seat for a stopper, a stopper sized to be engageable into the opening, and movable between a position in engagement with the opening and a position disengaged from the opening, an element for biasing the stopper into engagement with the opening, the biasing element comprising an expansion spring for biasing the stopper into engagement with the opening under normal operating conditions, and to be compressible in response to changes in fuel pressure to allow the stopper to become disengaged from the seat, a means for restricting the movement of the stopper to substantially linear movement, and a passageway for conducting fuel from the inlet.

10. The invention of claim 8 or 9 and further comprising an annular media concentrically disposed in the second space, and wherein the by-pass means conducts fuel from the space adjacent the annular media, through the passageway to the exit port.

11. In a fuel path, a by-pass means for a fuel-water separator having a plurality of spaces comprising an inlet having an opening through which liquid can pass, the inlet including a substantially cylindrical wall portion, a ceiling portion, and a floor portion containing the opening, the opening including a rim for serving as a seat for a stopper, a stopper sized to be engageable with the seat and movable between an engaged position and a disengaged position, the stopper comprising a substantially spherical structure, an element for biasing the stopper into engagement with the seat, and a passageway for conducting fuel from the inlet to a portion of the fuel system downstream of the by-pass means.