Patent ID: 12195323

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless expressly and unequivocally limited to one referent. The various embodiments and examples of the present invention as presented herein are each understood to be non-limiting with respect to the scope of the invention.

One aspect of the present invention provides a sump space10unit or system100for dewatering fuel in an underground fuel storage tank12that includes fuel filtration, coalescing, and water separation system with water storage and multiple operational modes. An underground fuel storage tank12within the meaning of this application is an underground storage tank12(UST) for fuel, and is ubiquitous for gas stations across the country. A detail discussion of UST12is found within the laws and regulations that governs underground storage tanks (USTs) and is available in the U.S. Code, Title 42, Chapter 82, Subchapter IX. This law currently incorporates amendments to Subtitle I of the Solid Waste Disposal Act as well as the UST provisions of the Energy Policy Act of 2005 and gives EPA the authority to regulate USTs.

Fuel delivery sump10within this application, and generally in the art, is an access space above an underground fuel storage tank12typically housing the pump and other access for the underground fuel storage tank12.

There are some other terms and phrases to be defined for better understanding of the features of the present invention. An element, such as element102and combined element104, within this application defines a fluid processing component with a media for treating the fluid such as particulate media for removing contaminants (in combined element104), coalescing media or layer (in combined element104) for coalescing fluid and separation layer (in element102) for separating components, typically by preventing passage of a component such as a hydrophobic layer for water. A combined element, such as104, is an element with two distinct media in a single integrated component.

Wet fuel16is defined herein as the fluid upstream of the system100of the present invention and in the underground fuel storage tank12generally above a petroleum-water, or boundary layer14, within the underground storage tank12unless otherwise specified. Water18will generally be fluid below the petroleum-water interface14in both the underground storage tank12and the system100of the present invention, and water will also include the fluid that is being separated from the wet fuel.

Dewatered fuel or clean fuel within the meaning of this application defines fuel downstream of the system100of the present invention being returned to the underground fuel storage tank12. In other words this is fluid, which will be mainly fuel, which has passed through the system100of the invention, allowing at least some of the water to be removed from the wet fuel by the system100. The “dewatered fuel” may still have trace amounts of water in the fuel.

The clean fuel essentially returns to the underground storage tank12and can then be considered, again, as wet fuel when returned to the underground storage tank12as once it is back in the tank12it is “upstream” again of the system100. With the return to the underground storage tank12, the clean fuel becomes “wet fuel” as it may pick up additional water in the underground fuel storage tank12, and this wet fuel may be processed again by the system100of the invention. It should be apparent that the wet fuel in the tank12is becoming less wet through the iterative application of the system100of the present invention that draws water from the fuel and the tank12.

The system100includes a) a system housing106configured to be placed within a fuel delivery sump space10above an underground fuel storage tank12; b) A particulate media element (part of combined element104) within the housing106; c) A coalescing media element (part of combined element104) within the housing106; d) A water separation media element102within the housing106; and e) A water/fuel storage area108within the housing106, which is formed generally by the lower part of the housing106. The system100is configured for multiple operational modes, including a first operational mode in which the system100is configured to receive wet fuel from the underground storage tank12and return clean fuel to the underground storage tank12wherein the flow is directed through at least one of the particulate media element104, the coalescing media element104and the water separation media element102, and a second operational mode in which the system100is configured in to receive water from the underground storage tank12wherein the water is directed into the housing106bypassing each of the particulate media element104, the coalescing media element104and the water separation media element102.

FIGS.1A and1Bare elevational front and side views, respectively, of a fuel delivery sump based fuel filtration, coalescing, and water separation system100with water storage108and multiple operational modes in accordance with one embodiment of the present invention andFIG.3is an exploded view of the fuel delivery sump based fuel filtration, coalescing, and water separation system100with water storage108ofFIGS.1A and1B.FIGS.4A and4Bare a perspective view and a top plan view, respectively, of the fuel delivery sump based fuel filtration, coalescing, and water separation system100with water storage108ofFIGS.1A and1Bwithin a sump space10. These figures show that the housing106is an oval structure, in plan view, formed by an upper head, also referenced as a ported head or element container110and a lower water storage unit108or bowl. As shown the height of the system100of the present invention is less than 32″ high and a width including a valve or flow control manifold112of less than 12″ and a width of about 15″. Excluding the flow control manifold112, the housing106has an oval shape in top plan view.

The housing106forms a water/fuel storage area108for the system100. The lower water storage area108of the housing106, below the element container110, preferably will hold at least about 2 gallons of water and generally around 5 gallons of water, while the system100operates with about 8 gallons of fluid in the housing106(the area of the lower water storage area108and of the element container110). The housing106may include a lifting eyelet114to facilitate placement and replacement of the system100within the sump space10.

As noted above the system100includes a particulate media element104within the housing106; a coalescing media element104within the housing106; and a water separation media element102within the housing106. In the embodiment shown inFIGS.1-4the particulate media element104is combined with the coalescing media element104forming a combined element104within the housing106and this is a drop in combined filter element104held within one cylindrical part of the element container110.

Regarding the structure of a combined particulate and coalescing filter element104see generally the applicant's Bulk Diesel Filter Cart (BDFC) designed for those wanting to maintain clean fuel in their bulk storage tanks. The BDFC provides exceptional particulate filtration and continuous water removal even with higher flow rates. The BDFC structure illustrates the construction and operation of a particulate pre-filter and coalescing water removal filter in a combined element104. The combined filter element104may be designed for inside out flow or outside in flow as designed and the element container110would be constructed accordingly.

The system100of the present invention shown inFIGS.1-4includes a water separation media element102within the housing106also formed as a drop in filter element held within the other cylindrical part of the element container110. The water separation media element102within the housing106includes a hydrophobic layer to prevent water from returning to the underground storage tank12thorough the water separation media element. The water separation media element102may be designed for inside out flow or outside in flow as designed and the element container110would be constructed accordingly.

The system100ofFIGS.1-4includes a boundary layer sensor116for detecting the water level within the housing106. The sensor116can be optical, electronic, and/or mechanical as generally known in the art. Underground storage tanks have water level sensor technology as well. The system ofFIGS.1-4includes will include a drain line118to remove water from the housing106as the stored water reaches a preset level. Additionally the system100ofFIGS.1-4includes sensing unit120to evaluate the element life to assist in determining when the media elements need replacement, and these element sensors120may take many forms known in the art of element monitoring.

The system100ofFIGS.1-4is configured for multiple operational modes. A first operational mode, called a fuel polishing mode, is provided in which the system100is configured to receive wet fuel from the underground storage tank12and return clean fuel to the underground storage tank12wherein the flow is directed through at least one of the particulate media element104, the coalescing media element104and the water separation media element102. In the fuel polishing operational mode of the system100wet fuel is delivered from underground storage tank via the tank pump20and line122to the upstream side of the particulate media element104and flows through the particulate media element104and through the coalescing element104into the housing106. The coalescing element104acts to remove at least some of the water from the wet fuel. Within the first operational mode at least some clean fuel flows through the water separation media element102within the housing106to return to the underground fuel storage tank12via return line124. The hydrophobic layer in the water separation element102prevents water from being returned to the tank12through this element102.

Additionally the housing includes a bypass outlet128near a top of the housing106that is fluidly coupled to the underground fuel storage tank12via bypass/sweep line126and which bypasses the water separation media element102. This bypass outlet128is above the inlet level for the water separation element102. In the first operational mode, or the fuel polishing mode, the clean fluid may flow through both the water separation media element102and line124or the clean fluid outlet128and line126to be returned to the tank12. The liquid at the upper level of the housing106will be clean fuel and the use of both the bypass outlet128and line126and the water separation media102pathways including line124allows the combined element104to set the operational flow parameters of the present invention. As the stored water in the housing106increases the water separation media102will prevent water (or fuel wetter than in the tank) from returning to the tank12through the system100and as the water/fuel interface reaches this level the water in the housing106will be drained via line118.

It is possible for the polishing mode to close the bypass opening128and only operate with the clean fuel flowing through the water separation element102, but this may limit the flow rate of the system100. Alternatively, it is possible that the polishing mode operates with the clean fuel flowing only through the bypass outlet128, such as where the water separation element102requires service. Thus, in the first operational mode, or the fuel polishing mode, it is preferred if the clean fluid may flow through either the water separation media element102or the clean fluid outlet128to be returned to the tank12.

The system100of the present invention ofFIGS.1-4has a second operational mode, a water pulling or priming mode, in which the system100is configured in to receive water from the underground storage tank12wherein the water is directed into the housing106bypassing each of the particulate media element104, the coalescing media element104and the water separation media element102. In the water pulling mode the fluid18is pulled from the tank12below the water/fuel interface14near the bottom of the tank12via line126and enters the housing106via the bypass opening108. This allows the system100of the invention to be primed after element replacement or water draining or the like. This mode more rapidly pulls water18from the tank12. The particulate and coalescing filter104is bypassed because the fluid is already essentially water and passing such through the combined filter element104will slow the flow parameters and significantly shorten the life of the combined element104.

In the priming mode, particularly after element replacement, the housing106may have an air gap and the system100may vent the air gap until the top of the fluid level approaches the entrance to the separation filter102, then the separation filter102would be used to return clean fluid to the tank12. In the priming mode the particulate and coalescing element104is closed as an inlet, and also fluid will not flow through this element104as a return pathway.

The distinct operational modes of the system ofFIGS.1-4allows for a compact but efficient system100to be constructed. The system100is configured to have an operational flow rate of at least 0.2 gallons per minute through the system in the low flow operational mode and a water capacity of at least 2 gallons. The system100is designed for effectively continuous operation, except for element replacement and system repair with the system100cycling between fuel polishing mode then water drainage and priming before returning to fuel polishing mode. The system100of the present invention is scalable to the sump space10size available, and sometimes without affecting the polishing rate flow parameters. For example another smaller system100may have only a 2 gallon water storage area108below the element container110. The reduction of the water holding capacity does not alter the operation other than to require cycling through the water removing and priming cycles more often between the semi-continuous polishing mode.

FIG.5is a schematic representation of a three element modular design, with the element container110thereof shown in perspective and in section, for use with a water storage housing in accordance with an alternative embodiment of the present invention. Specifically it illustrates a 3 unit element container for coupling to the lower water storage area108of the housing106ofFIGS.1-4. The ports130in each cylindrical bowl of the element container110as shown could be designed as either an inlet or outlet whereby the Inlet and outlet ports can be designated in order to establish the flow direction within an element (inside-out or outside-in). An end cap with a radial seal on the outside of the end cap, could separate the two ports130within a single cylindrical element receiving portion. A key aspect of this configuration is the provision of an element bypass port140: the primary function of this design is to remove water (intermittent phase) from diesel fuel (continuous phase). When those two phases switch (water becomes the continuous phase), the element bypass port140allows water to bypass the elements as discussed above. This allows the elements to maintain a high efficiency. The unit includes Drainage/Internal Interconnect Ports134: these can serve either of two functions: Allow water that is separated to drain into the sump of the housing, or Serve as an internal pathway from one element cavity to another. A Water Siphon Connection132is provided to yield an external pump can be connected in order to remove water from the sump108and a Water Siphon Downtube136is provided wherein the downtube136allows for water to be drained from the bottom of the sump108via connection132and eliminate/minimize any sitting water at the bottom of the sump.

For the embodiment ofFIG.5, any combination of element configuration (particulate and/or coalescing and/or separation) can be used, specific to an applications needs (high particulate contaminant, high water content). However consistent with the system described above the embodiment ofFIG.5may have a particulate filter element in series with a coalescing element in two bowls, likely adjacent bowls, and a water separation element in parallel in the third bowl. This arrangement would effectively operate in the same manner as described above.

An alternative arrangement forFIG.5is to have a single combined particulate coalescing element as with the design ofFIGS.1-4but two separate water separation filters for increased polishing flow through the separations filters. A further alternative arrangement is to have a two combined particulate coalescing elements each coupled to a different underground storage tank and using the same water storage area108. The remaining element can be a water separation element whose outlet flow is directed to the tank currently directing flow to the system.

Yet another configuration ofFIG.5is to have three combined particulate coalescing and water separation elements (3 in one element) each coupled to a different underground storage tank and using the same water storage area108. For such a three in one element the clean fuel would be directed back to the tank from the element, similar to the flow from the water separation element described above. The set up ofFIG.5is intended to provide a modular design for system designers to create the system100dictated by the particular application.

FIG.6is a schematic representation of a two element modular design, with the element container110thereof shown shown in perspective and in section, for use with a water storage housing106in accordance with an alternative embodiment of the present invention. Specifically it illustrates a two unit element container110for coupling to the lower water storage housing106ofFIGS.1-4. The ports130in each cylindrical bowl as shown could be designed as either an inlet or outlet whereby the Inlet and outlet ports130can be designated in order to establish the flow direction within an element (inside-out or outside-in). This unit is a more generic implementation of the system shown inFIGS.1-4, and if one bowl includes a combined particulate and coalescing element104and the other bowl includes a water separation element102with a hydrophobic layer it is essentially the system100described above inFIGS.1-4(with slightly different element sizing as shown),FIG.6, likeFIG.5is intended to yield a modular base for numerous implementations, for exampleFIG.6may have two combined particulate coalescing and water separation elements (3 in one element) each coupled to a different underground storage tank and using the same water storage. For such a three in one element the clean fuel would be directed back to the tank12from the element, similar to the flow from the water separation element described above. The setup ofFIG.6is intended to provide a modular two bowl design for system designers to create the system dictated by the particular application.

FIG.7is a schematic representation of a single element modular design, with the element container110thereof shown shown in perspective and in section, for use with a water storage housing106in accordance with an alternative embodiment of the present invention. Specifically it illustrates a single unit element container for coupling to the lower water storage housing ofFIGS.1-4. Obviously the unit ofFIG.7is utilized where only a single, likely combined element is implemented.

These and other alternatives of the present invention will be apparent to those of ordinary skill in the art and will not depart from the spirit and scope of the present invention which is defined by the appended claims and equivalents thereto.