1. Field of the Invention
This invention relates to a system for adding or removing fluid from storage, and in particular to an adjustable pick up device for removing fuel from a fuel storage tank.
2. Description of the Related Art
Many problems exist when storing fuel. Fuel is an organic compound that reacts with air, water and microbiological growth. It has a relatively short shelf life and will degrade over time. Thus when fuel is stored, contaminants are formed that settle out into the fuel. The heaviest contaminants fall to the bottom of the storage tank, while lighter particles remain suspended in layers in the fuel. As a result of this stratification, less contaminated fuel remains higher in the column.
In order to maximize the usable volume of a storage tank, fuel pick up tubes are often placed within a few inches of the bottom of the tank. Having the pick up tube near the bottom allows more fuel to be withdrawn before the need to refill the tank. This can be critical, especially for emergency power systems that may have to run for long periods of time without being refueled. Yet, such a design places the pick up tube in the most contaminated area of the stored fuel.
Other storage tank features contribute to fuel contamination problems. Some storage tanks are vented to the atmosphere to relieve pressure build up. Yet, such venting introduces moisture and airborne microorganisms into the tank, which eventually make their way to the bottom of the tank due to condensation and gravity. The microorganisms grow and reproduce in this environment, living in the water while feeding on the fuel. Over time, an interface layer, that can be made up of a stringy, black mass of sediments, will form between the fuel and the water. Additional sediments also form on the tank bottom as byproducts of the microorganisms' biological processes. As a result, the pH of accumulated water drops providing a corrosive environment. If left unchecked, layers of water and sludge accumulate from the bottom, and upward toward the middle of the storage tank.
Many storage tanks also have a return fuel line through which unused fuel is discharged back into the tank. The problem of suspended sludge accumulating near the bottom of the tank is compounded when diesel engines dump fuel back into the tank through this line.
Today's expensive fuel equipment has little tolerance for such dirty, contaminated fuel. For example, the orifices on injectors are smaller to make engines more fuel efficient. Consequently, the potential for injection wear is greater when fuel is delivered from a contaminated source. Moreover, due to the present practice of introducing chemicals to the fuel through the cracking process (to increase yield), current fuel types are more dynamic, and will precipitate particles that link together to form additional sludge. The National Fire Protection Association recognizes the potential for problems associated with contaminated fuel and has provided a Standard that “fuel system design shall provide for a supply of clean fuel to the prime mover.” NFPA Standard 110, 7.9.1.2.
Various attempts have been made for reducing the previously identified problems associated with stored fuel. Fuel storage tanks are typically inspected and periodically cleaned to remove the build up of contaminants. In addition, biocides or biostats can be added to the tank to destroy or inhibit the growth of microorganisms. Finally, filters can be installed and periodically changed. Because of budget constraints and differing maintenance philosophies, however, such measures are not always taken. What is needed is a fuel pick up device that will remove fuel from the cleanest part of the tank while maximizing the usable volume of a storage tank. It is to such a device that the present invention is primarily directed.
Briefly described in a preferred form, the present invention is a pick up device for communicating fluid with the interior of a tank. The pick up device includes an intake and a submerging member for maintaining the intake a distance below the top level of the fluid inside the tank, which top level varies as the tank is filled and emptied. The submerging member can be a float that enables the intake to rise or fall in sync with the varying level of fluid in the tank. The intake can communicate with a delivery member through which the fluid can enter or exit the tank. A prevention means can prevent the intake from passing into a predetermined volume of fluid in the tank where the unacceptably contaminated fluid is found. The present invention can also include a filter for preventing filterable contaminants in the fluid from entering or exiting the pick up device.
Although the pick up device of the present invention can be used to add or remove numerous types of fluid from a tank, its use is generally contemplated for liquids that develop contaminants while in storage, and more particularly used to remove liquid fuel from a storage tank. The term fuel as used herein will be understood to mean natural or synthetic fluids that yield heat through combustion, which includes, but is not limited to, gasoline, kerosene, diesel fuel, and heating oil.
The submerging member can further include an extension connecting the delivery member to the intake. The extension can be an adjustable arm that is preferably located midway between the top and bottom of the storage tank. The adjustable arm has an intake at one end, and is connected to the delivery member at the opposite end by a sealed swivel joint. The adjustable arm can thus swivel between the middle and the bottom of the tank.
The length of the adjustable arm varies in relation to the geometry of the storage tank in order to prevent the intake from entering an unacceptably polluted or contaminated volume of fuel near the bottom of the tank when it is in its lowest position. This ensures that the maximum storage capacity of the tank is utilized without allowing the intake to drop into a contaminated volume of fuel near the bottom of the tank. An air-filled tube float located at the intake end of the adjustable arm can provide buoyancy to that end of the adjustable arm enabling it to rise and fall with variations in the top level of the fuel in the storage tank.
In proximity to the air-filled tube float can be a downturned intake connected to a filter. When the storage tank is full of fuel, the floating adjustable arm is located midway in the depth of the fuel and the plane of the adjustable arm is at least approximately parallel with the plane of the bottom of the storage tank. The arm is maintained in place by a stopping member on the swivel joint that prevents the floating adjustable arm from rising above the midway position. In this orientation, fuel is removed from the middle of the tank where it is likely the least contaminated. The invention need not include such a stop, so the arm can rise above the parallel if such is appropriate. As the fuel level in the tank falls, the swivel joint enables the adjustable arm to likewise fall. The air-filled tube float at the intake end of the adjustable arm enables the arm to float near the surface of the fuel. The downturned intake remains submerged keeping a suction point below the surface of the fuel, preventing the suctioning of contaminants floating on top of the fuel, and preventing air from entering the line.
The stopping member on the swivel joint also prevents the floating adjustable arm from extending beyond the perpendicular of the bottom of the tank as the fuel level drops due to the removal of fuel from the tank. As fuel levels are restored beyond halfway of the tank, the floating adjustable arm will return to its highest position at the midpoint of the depth of the tank where it is again preferably parallel with the bottom of the tank, if the embodiment of the invention utilizes a stopping member.
In another embodiment the adjustable arm is retractable into the delivery member, rather than connected to it by a swivel joint. The delivery member is positioned generally perpendicular to the bottom of the storage tank so that the adjustable arm retracts or extends from the delivery member in relation to the top level of fuel in the tank due to gravity and the float at the intake end of the adjustable arm. The delivery member can be positioned either above or below the adjustable arm. It is preferable, however, to position the delivery member above the adjustable arm so that the adjustable arm extends from the delivery member toward the bottom of the tank to utilize the tank's maximum storage capacity.
The present invention further provides a system that reduces the need for frequent filter replacement because the intake is prevented from entering two separate layers of the most contaminated fuel. The submerging member maintains the intake a distance below the top level of the fuel in the tank to prevent the intake from passing into a predetermined volume of contaminated fuel near the top level of fuel in the tank. Whereas the prevention means prevents the intake from entering a predefined volume of contaminated fuel at the bottom of the tank. Accordingly, the system removes the majority of the fuel from an area of the tank where the cleanest fuel is likely found.
A principle object of the present invention is to provide an innovative fluid pick up device designed for removing an uncontaminated fluid stream from a fluid storage device.
Another object of the present invention is to provide an innovative fluid pick up device designed for removing liquids that develop contaminants while in storage from the cleanest portion of the storage tank.
It is another object of the present invention to provide a fluid pick up device that removes fuel from an area of a storage tank where the cleanest fuel is found while utilizing as much storage capacity of the tank as possible.
Yet another object of the present invention is to provide a convenient alternative to frequently cleaning the storage tank that is safe, economical, and easy to use.
Still another object of the present invention is to provide a fuel pick up device that minimizes the amount of contaminated fuel delivered to fuel equipment.
Another object of the present invention is to provide a fuel pick up device that reduces the need for filter replacement.
These and other objects, features and advantages of the present invention will become more apparent upon reading the following specification in conjunction with the accompanying drawings.
Referring now in detail to the drawing figures, wherein like reference numerals represent like parts throughout the several views,
In a preferred embodiment, pick up device 10 comprises an intake 110 and a submerging member 120 having an extension 100, such that intake 110 and a filter 140 remain submerged some distance ΔD below a top level X of the fuel F. The distance ΔD is defined as a varying distance from the top level of fluid F and depends on various factors such as type, size, and shape of tank 50, as well as concentration of contaminants in fuel F.
Submerging member 120 can be formed from a float material or comprise a separate float 122 that floats in relationship to the top level X of the fuel. Float 122 is in communication with extension 100, such that the intake 110 will rise and fall in relationship to the top level X of the fuel F inside the tank 50, but remain a distance ΔD below the top level X of the fluid to avoid contaminants floating on the surface of the fuel.
Extension 100 also communicates with a delivery member 130 through which the fluid F can enter or exit the tank 50. In a preferred embodiment, delivery member 130 is a flexible tube 132. The relationship between extension 100 and delivery member 130 can form a prevention means, such that intake 110 remains above a prescribed lower level Y of fuel F in the tank 50, as the fuel within a volume defined by lower level Y and the bottom 52 of tank 50 can be the most contaminated due to settled contaminants. Lower level Y is defined as a varying distance Δd above the bottom 52 of tank 50, and depends on various factors such as type, size and shape of tank 50 as well as concentration of contaminants in fluid F. Preferably, Δd is at least six inches from the bottom 52 of the tank 50 and more preferably in the range of six to eight inches. The prevention means is adjustable by adjusting the length of delivery member 130 and/or the length of extension 100, preventing intake 110 from passing into the volume of contaminated fuel F below lower level Y. A person of ordinary skill in the art, however, will recognize that changes in size, shape, or rearrangement of extension 100 and the delivery member 130 to one another will also accomplish this goal and may be necessary for individual storage tanks.
Adjustable arm 200 is preferably confined to the range of motion between positions A and B by a stopping member 150 (FIGS. 4 and 5), although adjustable arm 200 need not be so confined, and could swivel beyond 90° if the swivel joint 135 does not incorporate a stopping member to so inhibit rotation. The prevention means of this embodiment can comprise a predefined length of arm 200, wherein the length of adjustable arm 200 preferably is set so that intake 110 does not pass into volume Y of the fuel. A filter 140 is also shown on the free end of adjustable arm 200 with a float 122 positioned between filter 140 and the base end of adjustable arm 200. Alternatively, the arm 200 can be formed of a floatable material such that an additional float 122 element need not be necessary.
The float and filter of the arm 200 shown in
A front view of yet another embodiment of the present invention is shown in FIG. 9. In this embodiment, extension 100 includes an adjustable arm 300 that is telescoping with delivery member 130. Delivery member 130 can be a straight tube 330 adapted to receive adjustable arm 300 within it. Adjustable arm 300 includes an intake 310, a float 322, and a filter 340. Gravity and float 322 enable adjustable arm 300 to extend from or retract into delivery member 330 in relationship to a top level X of fuel F in a storage tank 50, while keeping intake 310 submerged a distance ΔD below top level X.
The pick up device of the present invention is preferably constructed of non-corrosive materials. The delivery member, extension, and intake can be made of, for example, carbon steel or aluminum alloy. The elements can also include plastic parts specifically on the float, preferably as such plastics are non-reactive and impervious to the stored fuel. Although the present invention is suitable for several types of storage tanks, it is best suited for use with stationary tanks including vertical, horizontal, oblong, belly, aboveground, and underground storage tanks. Storage tank capacity will typically range from 50 to 50,000 gallons and larger tanks may be custom fitted.
Generally, the basic formula for fitting the device to individual tanks is the height of the tank (or diameter of the end of an oblong tank viewed from the side), minus at least six to eight inches, divided by two. Such a calculation may be used to identify the middle layer of fluid for placement of the adjustable arm when the tank is full. The delivery member should extend toward this middle layer such that the adjustable arm rests near this middle layer or higher when the adjustable arm is at its highest position in the tank. Such positioning allows for removal of fluid from an area of the tank that is least likely contaminated. The six to eight inches subtracted from the above measurement accounts for the preferable distance between the intake and the bottom of the tank when the adjustable arm is fully extended. Floating the adjustable arm depends on the length of the arm, the weight of the material used, and the buoyancy of the float. The delivery member is also preferably offset from center at least proportionate to the length of the swivel joint so that the adjustable arm is substantially in the vertical center of the tank when it is fully extended.
Numerous characteristics and advantages have been set forth in the foregoing description, together with details of structure and function. While the invention has been disclosed in its preferred forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions, especially in matters of shape, size, and arrangement of parts, can be made therein without departing from the spirit and scope of the invention and its equivalents as set forth in the following claims. Therefore, other modifications or embodiments as may be suggested by the teachings herein are particularly reserved as they fall within the breadth and scope of the claims here appended.
This application claims priority from Provisional Application Ser. No. 60/452,990 filed Mar. 7, 2003 entitled “Floating Arm Pick Up Device”.
Number | Name | Date | Kind |
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558131 | Warren | Apr 1896 | A |
781093 | Post | Jan 1905 | A |
836335 | Nichols | Nov 1906 | A |
1064102 | Smith et al. | Jun 1913 | A |
1528003 | Yarnall | Mar 1925 | A |
3381709 | Pregno | May 1968 | A |
3438215 | Willem | Apr 1969 | A |
Number | Date | Country | |
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20040173266 A1 | Sep 2004 | US |
Number | Date | Country | |
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60452990 | Mar 2003 | US |