We, Andrew Seitz, Scott F. Surdick and Christopher Bortnik, employees of the applicant Schroeder Industries, LLC, have developed a fuel delivery sump based fuel treatment system and method.
Vehicle fuel delivery systems typically includes one or more underground storage tanks that store various fuel products, and one or more fuel dispensers that dispense the fuel products to consumers. The underground storage tanks may be coupled to the fuel dispensers via corresponding underground fuel delivery lines. In the context of an automobile fuel delivery system, for example, the fuel products may be delivered to consumers' automobiles. In such systems, the fuel products may contain a blend of gasoline and alcohol, specifically ethanol. Blends having about 2.5 vol. % ethanol (“E-2.5”), 5 vol. % ethanol (“E-5”), 10 vol. % ethanol (“E-10”), or more, in some cases up to 85 vol. % ethanol (“E-85”), are now available as fuel for cars and trucks in the United States and abroad. Other fuel products include diesel and biodiesel, for example.
Sumps (i.e., pits) generally may be provided around the equipment of the fuel delivery system. Such sumps may trap liquids and vapors to prevent environmental releases. Also, such sumps may facilitate access and repairs to the equipment. Sumps may be provided in various locations throughout the fuel delivery system. For example, dispenser sumps may be located beneath the fuel dispensers to provide access to piping, connectors, valves, and other equipment located beneath the fuel dispensers. As another example, turbine sumps may be located above the underground storage tanks to provide access to turbine pump heads, piping, leak detectors, electrical wiring, and other equipment located above the underground storage tanks. Fuel delivery sump within this application, and generally in the art, is an access space above an underground fuel storage tank typically housing a pump and other access for the underground fuel storage tank.
In some instances, small amounts of water or debris may be introduced into the storage tank, which can degrade the fuel. In a 2016 study of North Carolina gas stations more than 20 percent of the state's gas station violations related to water contaminating the fuel. For example, during periods of rain, water typically flows over pavement in the forecourt region of a service station into a storm drain. Occasionally, some of this water may make its way into an underground storage tank. Generally, water and debris are denser than the fuel stored in the tank and thus settle near the bottom of the tank. Water and fuel are immiscible, which causes a water layer to form below the fuel creating a fuel/water interface layer in the storage tank. The level of the fuel/water interface is typically monitored to ensure that water is not introduced into the inlet through which fuel is drawn from the tanks.
Many gas stations have their gas storage tanks equipped with an electronic alarm that will sound when it senses water. The station may also physically test the gas for water with a color-metric tool that turns from white to burgundy when it detects water. One solution, when water is detected within the gas above a certain level, the stations call their distributor to send a pump truck to suck the tainted fuel out of the ground and then refill the tank with good gas. It's an expensive and laborious process and it could ruin a tank of 5,000-10,000 gallons of gasoline.
On-site remediation systems have been proposed. For example, U.S. Patent Application Publication 2018-0257925 states that “Water and/or particulate matter sometimes also contaminates the fuel stored in underground storage tanks. Because these contaminants are generally heavier than the fuel product itself, any water or particulate matter found in the storage tank is generally confined to a “layer” of fuel mixed with contaminants at bottom of the tank. Because dispensation of these contaminants may have adverse effects on vehicles or other end-use applications, efforts have been made to timely detect and remediate such contaminants.” Specifically it has been proposed in U.S. Patent Application Publication 2018-0257925 to provide a filter element, namely a coalescing filter element, is configured to separate water, including emulsified water and free water, from fuel product. The element is disclosed as coalescing the water into relatively heavy droplets that separate from the relatively light fuel product and settle at the lower end of element housing. Incoming fuel pressure drives fuel radially outwardly through the sidewall of filter element, while any water that is separated from the fuel is driven downwardly through the bottom of filter element and falls by gravity to the bottom of the filter housing. For similar systems see U.S. Patent Application Publication 2020-0017351.
Another system is taught in U.S. Patent Application Publication 2020-0102207 which teaches a fuel conditioning and filtration element that separates the contaminants and water from the fuel and which is located in a housing. The filter element is a coalescing filter capable of separating free and emulsified water from the fuel flowing there through while also removing other contaminants from the fuel. Similar systems are taught in U.S. Patent Application Publications 2020-0102206, 2020-0102205, and 2019-0062142.
The above identified U.S. Patent Application Publications represent the current state of the art of fuel delivery sump based fuel treatment systems and methods and these publications are incorporated herein by reference, yet there remains a need for a simple efficient and effective fuel delivery sump based fuel treatment system and method.
One embodiment of the present invention provides a sump space unit for dewatering fuel in an underground fuel storage tank that includes fuel filtration, coalescing, and water separation system with water storage and multiple operational modes. The system includes a) a system housing configured to be placed within a fuel delivery sump space above an underground fuel storage tank; b) A particulate media element within the housing; c) A coalescing media element within the housing; d) A water separation media element within the housing; and e) A water/fuel storage area within the housing. The system is configured for multiple operational modes, including a first operational mode in which the system is configured to receive wet fuel from the underground storage tank and return clean fuel to the underground storage tank wherein the flow is directed through at least one of the particulate media element, the coalescing media element and the water separation media element, and a second operational mode in which the system is configured in to receive water from the underground storage tank wherein the water is directed into the housing bypassing each of the particulate media element, the coalescing media element and the water separation media element.
These and other advantages of the present invention will be clarified in the detailed description of the preferred embodiments taken together with the associated figures.
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 space 10 unit or system 100 for dewatering fuel in an underground fuel storage tank 12 that includes fuel filtration, coalescing, and water separation system with water storage and multiple operational modes. An underground fuel storage tank 12 within the meaning of this application is an underground storage tank 12 (UST) for fuel, and is ubiquitous for gas stations across the country. A detail discussion of UST 12 is 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 sump 10 within this application, and generally in the art, is an access space above an underground fuel storage tank 12 typically housing the pump and other access for the underground fuel storage tank 12.
There are some other terms and phrases to be defined for better understanding of the features of the present invention. An element, such as element 102 and combined element 104, within this application defines a fluid processing component with a media for treating the fluid such as particulate media for removing contaminants (in combined element 104), coalescing media or layer (in combined element 104) for coalescing fluid and separation layer (in element 102) for separating components, typically by preventing passage of a component such as a hydrophobic layer for water. A combined element, such as 104, is an element with two distinct media in a single integrated component.
Wet fuel 16 is defined herein as the fluid upstream of the system 100 of the present invention and in the underground fuel storage tank 12 generally above a petroleum-water, or boundary layer 14, within the underground storage tank 12 unless otherwise specified. Water 18 will generally be fluid below the petroleum-water interface 14 in both the underground storage tank 12 and the system 100 of 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 system 100 of the present invention being returned to the underground fuel storage tank 12. In other words this is fluid, which will be mainly fuel, which has passed through the system 100 of the invention, allowing at least some of the water to be removed from the wet fuel by the system 100. The “dewatered fuel” may still have trace amounts of water in the fuel.
The clean fuel essentially returns to the underground storage tank 12 and can then be considered, again, as wet fuel when returned to the underground storage tank 12 as once it is back in the tank 12 it is “upstream” again of the system 100. With the return to the underground storage tank 12, the clean fuel becomes “wet fuel” as it may pick up additional water in the underground fuel storage tank 12, and this wet fuel may be processed again by the system 100 of the invention. It should be apparent that the wet fuel in the tank 12 is becoming less wet through the iterative application of the system 100 of the present invention that draws water from the fuel and the tank 12.
The system 100 includes a) a system housing 106 configured to be placed within a fuel delivery sump space 10 above an underground fuel storage tank 12; b) A particulate media element (part of combined element 104) within the housing 106; c) A coalescing media element (part of combined element 104) within the housing 106; d) A water separation media element 102 within the housing 106; and e) A water/fuel storage area 108 within the housing 106, which is formed generally by the lower part of the housing 106. The system 100 is configured for multiple operational modes, including a first operational mode in which the system 100 is configured to receive wet fuel from the underground storage tank 12 and return clean fuel to the underground storage tank 12 wherein the flow is directed through at least one of the particulate media element 104, the coalescing media element 104 and the water separation media element 102, and a second operational mode in which the system 100 is configured in to receive water from the underground storage tank 12 wherein the water is directed into the housing 106 bypassing each of the particulate media element 104, the coalescing media element 104 and the water separation media element 102.
The housing 106 forms a water/fuel storage area 108 for the system 100. The lower water storage area 108 of the housing 106, below the element container 110, preferably will hold at least about 2 gallons of water and generally around 5 gallons of water, while the system 100 operates with about 8 gallons of fluid in the housing 106 (the area of the lower water storage area 108 and of the element container 110). The housing 106 may include a lifting eyelet 114 to facilitate placement and replacement of the system 100 within the sump space 10.
As noted above the system 100 includes a particulate media element 104 within the housing 106; a coalescing media element 104 within the housing 106; and a water separation media element 102 within the housing 106. In the embodiment shown in
Regarding the structure of a combined particulate and coalescing filter element 104 see 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 element 104. The combined filter element 104 may be designed for inside out flow or outside in flow as designed and the element container 110 would be constructed accordingly.
The system 100 of the present invention shown in
The system 100 of
The system 100 of
Additionally the housing includes a bypass outlet 128 near a top of the housing 106 that is fluidly coupled to the underground fuel storage tank 12 via bypass/sweep line 126 and which bypasses the water separation media element 102. This bypass outlet 128 is above the inlet level for the water separation element 102. In the first operational mode, or the fuel polishing mode, the clean fluid may flow through both the water separation media element 102 and line 124 or the clean fluid outlet 128 and line 126 to be returned to the tank 12. The liquid at the upper level of the housing 106 will be clean fuel and the use of both the bypass outlet 128 and line 126 and the water separation media 102 pathways including line 124 allows the combined element 104 to set the operational flow parameters of the present invention. As the stored water in the housing 106 increases the water separation media 102 will prevent water (or fuel wetter than in the tank) from returning to the tank 12 through the system 100 and as the water/fuel interface reaches this level the water in the housing 106 will be drained via line 118.
It is possible for the polishing mode to close the bypass opening 128 and only operate with the clean fuel flowing through the water separation element 102, but this may limit the flow rate of the system 100. Alternatively, it is possible that the polishing mode operates with the clean fuel flowing only through the bypass outlet 128, such as where the water separation element 102 requires 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 element 102 or the clean fluid outlet 128 to be returned to the tank 12.
The system 100 of the present invention of
In the priming mode, particularly after element replacement, the housing 106 may have an air gap and the system 100 may vent the air gap until the top of the fluid level approaches the entrance to the separation filter 102, then the separation filter 102 would be used to return clean fluid to the tank 12. In the priming mode the particulate and coalescing element 104 is closed as an inlet, and also fluid will not flow through this element 104 as a return pathway.
The distinct operational modes of the system of
For the embodiment of
An alternative arrangement for
Yet another configuration of
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.
The present application claims the benefit of Provisional Patent Application Ser. No. 63/022,539 filed May 10, 2020 titled “Fuel Delivery Sump Based Fuel Filtration, Coalescing, and Water Separation System with Water Storage and Multiple Operational Modes
Number | Date | Country | |
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63022539 | May 2020 | US |