This application relates to an inflatable bladder system and more particularly relates to an inflatable bladder system for use in connection with the bulk liquid transport industry.
Surge and slosh are big problems in the bulk liquid transport industry. When a vehicle hauling a trailer carrying liquid is slowed down, for example, the liquid being carried tends to continue moving forward even though the vehicle is slowing down. This continued movement can create a force that tends to make safely braking more difficult. This is true even to some extent even if the trailer has one or more internal baffles to temper the effect. Moreover, even when stopped, the liquid may continue sloshing back and forth creating instability and making the vehicle more difficult to safely control.
In one aspect, a system (typically on a bulk liquid transport vehicle) includes a liquid storage tank, one or more liquid storage compartments inside the liquid storage tank, an inflatable bladder inside each of the liquid storage compartments, a compressed air system to provide compressed air to inflate each one of the inflatable bladders, and one or more valves. Each of the valves is configured to control air flow between the compressed air system and a corresponding one of the inflatable bladders and/or to control air flow between the corresponding inflatable bladder and atmosphere.
In another aspect, a system includes a liquid storage tank, a plurality of baffles inside the liquid storage tank, wherein the baffles divide the liquid storage tank longitudinally into a plurality of liquid storage compartments, an inflatable bladder inside each of the liquid storage compartments, a compressed air system configured to provide compressed air to inflate the inflatable bladders, and a plurality of valves, wherein each valve is configured to control air flow between the compressed air system and a corresponding one of the inflatable bladders and/or to control air flow between the corresponding inflatable bladder and atmosphere.
In some implementations, one or more of the following advantages are present.
For example, the systems and techniques disclosed herein are useful in the transportation industry, specifically liquid bulk transport. One feature that the inflatable bladders provide is to control or eliminate slosh and surge. How it works: inflating a bladder essentially makes any “half full” or “partially full” compartment, into a full (or more full) compartment. This helps reduce the potentially deleterious effects of liquid movement, including slosh and surge, in a tank being hauled.
In a typical implementation, the systems and techniques disclosed herein provide improvements over more traditional approaches including, for example, the use of traditional baffles and drop-in baffles.
Traditional baffles typically only REDUCE surge and slosh in a FRONT TO BACK motion, but have NO benefits for SIDE TO SIDE surge, which is felt while on turns, or in an emergency swerve situation.
Unlike baffles that rely on blocking surge and transferring it through the tank to the truck, drop-in baffles (for example Surge Buster® drop-in baffles) dissipate energy within the tank. Nothing is securely attached to the walls of the tank. The resulting benefit to the liquid load hauler is a safer load, reduced stress and fatigue on the driver, plus a reduction in vehicle maintenance cost as well as longer tank life. However, one problem with the drop-in baffles is that it can be impractical for everyday use. Generally, someone has to climb onto the top of the tank and be handed hundreds of these drop in baffles, just to make a difference. But then what? Then you have to fish them out? Clean them? Store them somewhere until next time? This can be time consuming and impractical. Additionally, even with these drop in baffles, there is still some front to back surge, as well as side to side surge.
Some benefits of certain implementations of the inflatable bladder system for liquid surge control disclosed herein include:
Other features and advantages will be apparent from the description and drawings, and from the claims.
Like reference characters refer to like elements.
Moreover, the illustrated vehicle 100 has an inflatable bladder system 101 for controlling undesirable movement (e.g., surge, slosh, etc.) of bulk liquid being transported within the tank 102. In a typical implementation, the inflatable bladder system 101 is able to control surge in virtually all directions, including longitudinally (i.e., defined by the vehicle's direction of motion) as well as laterally (i.e., side-to-side). Moreover, in a typical implementation, the inflatable bladder system 101 can control movement of the liquid anytime there is an amount of liquid in the tank 102 that has potential to create vehicle stability problems, regardless of whether the actual liquid level in the tank 102.
The system 101 in the illustrated implementation includes a plurality of baffles 104 (four in the illustrated implementation) that divide the tank 102 internally, in a longitudinal direction, into five discrete liquid storage compartments 106. Each baffle 104 laterally dissects the liquid storage tank 102. The internal baffles 104 are pretty evenly spaced so that each internal compartment 106 is about the same size as the others. The baffles 104 can take on any one of a variety of possible configurations. For example, in some implementations, the baffles 104 are solid barriers that completely isolate, and prevent the flow of liquid, between adjacent liquid storage compartments 106. In some implementations, the baffles 104 have one or more openings that may allow some, typically a small amount, of the liquid in one of the compartments to flow into and back from an adjacent one of the compartments. In a typical implementation, the baffles 104 help temper deleterious effects that liquid movement (e.g., surging or sloshing) in a longitudinal direction might have on vehicle stability.
An inflatable bladder 108 is inside each respective one of the liquid storage compartments 106. Each inflatable bladder 108 in the illustrated implementation is a hollow, flexible bag that can be inflated or deflated to fill more or less of its corresponding liquid storage compartment 106. In this regard, the vehicle has a compressed air system 107 that is configured to provide compressed air that can be introduced into the inflatable bladders 108 to inflate the inflatable bladders 108. Moreover, each inflatable bladder 108 can be deflated by releasing the compressed air from inside the inflatable bladder 108 (e.g., to atmosphere). The air released into the atmosphere would not include vapor from any of the liquids being stored in the liquid storage compartments 106, but is generally fresh air from within the inflatable bladders 108, which would have come from the vehicle's compressed air system.
The vehicle's compressed air system 107 includes an air compressor 110, a receiver tank 112 coupled to the air compressor 110, and pneumatic lines (e.g., tubes or pipes) to carry compressed air throughout the system 107 including for use in connection with inflating the inflatable baffles 108. The air compressor 110 can be virtually any kind of device that converts power (e.g., from an electric motor, diesel or gasoline engine, etc.) into potential energy stored in the form of pressurized air (i.e., compressed air). During operation, the air compressor typically forces air into the receiver tank 112, increasing pressure in the receiver tank 112 as more and more compressed air is introduced. In a typical implementation, when the pressure inside the receiver tank 112 reaches an upper limit the air compressor 110 shuts off. The compressed air, then, is held in the tank until called into use (e.g., to inflate one or more or all of the inflatable bladders or for some other purpose/application). As the compressed air is released from the receiver tank 112, the pressure inside the receiver tank 112 goes down. When the pressure inside the receiver tank 112 reaches a lower limit, the air compressor 110 turns on again and re-pressurizes the receiver tank 112. In a typical implementation, the receiver tank 112 acts as a reservoir of compressed air for peak demands, helps remove water from the system by allowing the compressed air a chance to cool, and minimizes pulsation in the compressed air system that might be caused, for example, by a reciprocating air compressor cycling on and off to meet a varying demand or by some cyclic process downstream of the air compressor.
The system 101 includes valves 114 that open and close to control air flow between the vehicle's compressed air system and the inflatable bladders 108 and control air flow between the inflatable bladders 108 and atmosphere. In some implementations, the valves 114 are solenoid valves. In some such implementations, each solenoid valve 114 has an inlet port that is connected to the vehicle's compressed air system, an outlet port that is connected to a corresponding one of the inflatable bladders 108, and a vent that provides a flow path from the corresponding inflatable bladder 108 to atmosphere.
Each solenoid valve 114 has a solenoid. A solenoid is a coil of wire, usually in a cylindrical form that acts as a magnet when carrying an electrical current. Typically, this magnetic action causes a ferromagnetic core, for example, to move relative to the coil, which can be used to control a mechanical device, such as the valve portion of the solenoid valve 114. A solenoid valve is a valve that has one or more solenoids that can act to cause the valve to open or close one or more flow paths through the valve.
In the illustrated implementation, each solenoid valve 114 is mounted on an upper, outer surface of liquid storage tank 102. In a typical implementation, each solenoid valve 114 would be next to an access manhole for the corresponding liquid storage compartment 106. The inflatable bladder 108 for that liquid storage compartment 106 is attached to the bottom of the solenoid valve 114 (inside of the liquid storage compartment 106). Typically, each opening in the liquid storage tank 102 that allows one of the inflatable bladders 108 to be attached to its corresponding solenoid valve 106 is sealed around the bladder 108, the solenoid valve 106, or both to prevent vapors or fluids from accidentally escaping the liquid storage tank 102 through the opening.
The system 101 also has a control box 116 with a user interface that enables a human user to selectively inflate or deflate any one or more or all of the inflatable bladders 108. In an exemplary implementation, the user interface might include five “fill/deflate” rocker switches or buttons—one for each inflatable bladder 108—that the user can manipulate to inflate or deflate any one or more, or all, of the inflatable bladders 108 with air. The control box 116 sends electrical signals to the solenoid valves 114 for the inflatable bladders 108, via electrically conductive wires (represented as dashed lines in the schematic illustration), to cause the solenoid valves 114 to behave in a variety of ways described herein.
For example, if the control box 116 sends a signal to a particular solenoid valve 114 indicating that a corresponding inflatable bladder 108 should be inflated, then that particular solenoid valve 114 would open a fluid flow path between its inlet port (connected to the compressed air system 107) and its outlet port (connected to the corresponding inflatable bladder 108) and also close its vent to atmosphere. Alternatively, if the control box 116 sends a signal to a particular solenoid valve 114 indicating that a corresponding inflatable bladder 108 should be deflated, then that particular solenoid valve 114 would open its vent to atmosphere and close (or keep closed) the flow path between its inlet port (connected to the compressed air system 107) and its outlet port (connected to the corresponding inflatable bladder 108).
According to some implementations, the user interface on the control box has rocker switches that can be manipulated by a user to inflate or deflate each of the inflatable bladders 108. In such implementations, if the user moves the rocker switch for one of the inflatable bladders 108 to a “fill” position, the control box 116 causes the associated solenoid valve 114 to move into configuration that results in air flowing from the vehicle's compressed air system into the inflatable bladder 108.
Typically, air continues to flow into the inflatable bladder 108 until the inflatable bladder 108 is sufficiently full (e.g., until the air inside the inflatable bladder 108 reaches a target pressure that indicates the inflatable bladder 108 is sufficiently full). In this regard, the system includes a pressure sensor 118 to sense pressure inside each respective one of the inflatable bladders 108. Each pressure sensor 118 in the illustrated implementation is shown as being inside each inflatable bladder 108. However, in some implementations, each pressure sensors 118 may be outside of its inflatable bladder, but connected (e.g., via an air pressure sensing line) to its inflatable bladder. In some implementations, the pressure sensors 118 may operate similar to a typical tire pressure monitoring system (TPMS) sensor which senses pressure on the inside of a tire.
In general, during inflation, as air is pushed into one of the inflatable bladder 108, the inflatable bladder 108 expands to occupy more and more of the volume inside its liquid storage compartment 106. Eventually, the expanding inflatable bladder 108 begins to press down on the liquid inside the liquid storage area, and the pressure inside the inflatable bladder rises.
The pressure sensors 118 in the illustrated system 101 may provide electrical signals to the control panel 116 indicative of the pressure being sensed. In a typical implementation, if a user has instructed the system 101 to inflate a particular inflatable bladder 108, the system 101 will deliver compressed air into that inflatable bladder 108 until the pressure in that inflatable bladder reaches some predetermined value (e.g., a target pressure, that may have been programmed into computer-based memory within or accessible from a control panel 116). If a computer-based processor (e.g., within or in communication with the control panel 116) determines that the pressure inside one of the inflatable bladders 108 has reached the predetermined value, the processor causes the control panel 116 to send a signal to the solenoid valve 114 for that inflatable bladder 108 to move into a configuration that closes the fluid flow path between the compressed air system 107 and the inflatable bladder 108 while keeping its vent closed as well.
The target pressure (that indicates the inflatable bladder 108 is sufficiently full) can be any one of a variety of possible pressures, but is typically less than 120 pounds per square inch (psi). In some implementations, the target pressure is the pressure at which the inflatable bladder 108 fills, or at least substantially fills, any otherwise empty space above any liquid that is inside the liquid storage compartment 106. By filling, or substantially filling, this otherwise empty space, the inflated inflatable bladder 108 can eliminate, or substantially minimize, any undesirable surging or sloshing of liquid inside the liquid storage tank 102 as the vehicle moves about (and stops and starts).
In a typical implementation, the pressure sensors 118 are able to communicate with the control box 116. Once the target pressure inside an inflatable bladder 108 is reached, and the pressure sensor 118 inside the inflatable bladder 108 senses that the target pressure has been reached, the pressure sensor 118 sends a shut-down signal, wirelessly or over a wired connection (not shown in the figure) to the control box. In response to the shut-down signal, the control box 116 causes the associated solenoid valve 114 to move into a closed configuration, where the solenoid valve prevents any air from moving into or out of the now-inflated, inflatable bladder 108.
Continuing this example, if the user subsequently moves the rocker switch associated with the now-inflated, inflatable bladder, to a “deflate” position, the control box 116 causes the associated solenoid valve 114 to move into a venting configuration, in which the vent for that solenoid valve opens and allows air from inside the inflatable bladder 108 to escape to the atmosphere, while preventing any additional air from the compressed air system from entering the inflatable bladder 108.
In some implementations, the pressure sensor 118 inside the deflating inflatable bladder 108 will monitor pressure inside that bladder 108 and send signals to the control panel 116 while the inflatable bladder 108 is deflating. In some such implementations, deflation (e.g., venting through the open vent of the solenoid valve 114) continues until the pressure in that inflatable bladder 108 reaches some predetermined value (e.g., a target deflated pressure, that may have been programmed into computer-based memory within or accessible from the control panel 116). If the computer-based processor (e.g., within or in communication with the control panel 116) determines that the pressure inside one of the inflatable bladders 108 has reached the predetermined value (e.g., target deflated pressure), the processor causes the control panel 116 to send a signal to the solenoid valve 114 for that inflatable bladder 108 to move into a configuration that closes the vent, also leaving the fluid flow path between the compressed air system 107 and the inflatable bladder 108 closed as well.
It is possible that, over time, one or more of the inflated inflatable bladders 108 may lose some of its air (e.g., by leakage or the like). If that happens, the pressure in the leaking inflatable bladder 108 goes down. The pressure sensor 118 in the leaking inflatable bladder 108 senses the drop on pressure and sends a signal to the control panel 116 of the sensed pressures. In some such implementations, the system 101 is configured to deliver a fresh charge of air (from the compressed air system 107) into the leaking inflatable bladder 108 to make up for lost air. In those implementations, if the computer-based processor (e.g., within or in communication with the control panel 116) determines that the pressure inside one of the inflatable bladders 108 has reached a predetermined value (e.g., target air-loss pressure), the processor causes the control panel 116 to send a signal to the solenoid valve 114 for that inflatable bladder 108 to move into a configuration that opens the fluid flow path between the compressed air system 107 and the inflatable bladder 108 closed, while leaving the vent for that solenoid valve 114 closed. Once the computer-based processor determines that the pressure inside the inflatable bladder 108 has been restored (to some predetermined value stored in computer-based memory), the processor causes the control panel 116 to send a signal to the solenoid valve 114 for that inflatable bladder 108 to move into a configuration that closes the fluid flow path between the compressed air system 107 and the inflatable bladder 108 closed, while leaving the vent for that solenoid valve 114 closed.
The partial cross-sectional portions of these figures reveal certain internal details of liquid storage tank 102.
For example, the partial cross-sectional portions of these figures reveal that the liquid storage tank 102 has internal surfaces that are substantially oblong in cross-section about a longitudinal, horizontal axis of the vehicle.
Moreover, the partial cross-sectional portions of these figures provide a detailed perspective view of some of the internal baffles 104. As illustrated, each internal baffle is slightly curved to define a concave forward-facing surface and a convex rearward-facing surface. The internal baffles 104 laterally dissect the liquid storage tank 102 and are pretty evenly spaced so that each internal compartment 106 (i.e., the spaces between adjacent baffles 104, the space between the forward-most baffle and the front of the liquid storage tank 102, and the space between the rearward-most baffle and the rear of the liquid storage tank 102) is about the same size as the others.
In various implementations, any or all of the baffles 104 can have one or more or no openings or notches that allow some amount of liquid to flow between adjacent compartments 106 within the liquid storage tank 102. For example, the forward-most baffle in the illustrated implementation has a centrally-disposed opening 220 and notches 222 at the top and bottom of the baffle 104 that provide fluid flow openings between adjacent internal compartments 106. Other types of openings, notches, etc. may be formed in any one or more of the baffles 104 in a particular implementation. Moreover, the size, shape, number and/or configuration of openings or notches in the different baffles 104 in a particular system can vary or be the same. In a typical implementation, aside from any notches that a particular baffle might have at its edge, the baffles 104 otherwise extend entirely to the internal, substantially oblong surface of the liquid storage tank 102—to contact and seal against that internal, substantially oblong surface.
The inflatable bladders 108 are inside each of the liquid storage compartments 106.
The inflatable bladder 108 is made from a material suitable for use in whatever environment the inflatable bladder 108 is intended to be used. One possible material that the inflatable bladder 108 may be made from is the same type of material as a Petro-Flex® fuel bladder, available from ATL® (Aero Tec Laboratories). This material would make the inflatable bladder 108 be appropriate for use in connection with hauling a wide range of petroleum products including, for example, gasoline, diesel, jet fuel, lube oil, crude oil, heating oil, etc.—in some cases, all fuels. This material is light, strong, flexible, and highly collapsible. Different materials may be used in other applications. For example, if the liquid to be hauled is going to be a consumable liquid, such as milk, the material should be one that won't contribute any flavor to the liquid if or when it comes into contact with the liquid. In some implementations, the bladder material is rip-stop nylon and may include a polyurethane coating. This may provide for excellent waterproofing, durability, and be relatively light in weight.
In a typical implementation, the bladder can be thought of as performing the “work” of keeping the liquid load stabilized, as well as filling up any “empty” space in the compartment, essentially making any partially full compartment into a full compartment. It is much safer to transport liquid with a full compartment as compared to a partially full compartment.
Of course, a wide variety of solenoid valves 114 may be suitable for use in the system of
In some implementations, system installation might include the following steps (not necessarily performed in this order): 1) tap into the vehicle's main air supply (usually regulated to 120 psi) using a single splitter, 2) run an airline from the splitter up into the rail in the walkway on the roof of the tank (each compartment may need an additional splitter to supply air to the inflation valve), 3) mount the control box inside of a can box, preferably next to the Scully system, and 4) run the wires from the control box up into the rail in the walkway on the roof (may be able to use the same wire path as the Scully to probe wires).
The illustrated implementation shows a manhole cover 1150 and a solenoid valve 1114 atop the tank. Since the solenoid 1114 has the bladder attached to the bottom of it (on the inside of the tank), there needs to be a way to access the connection points. Having the manhole access close by gives adequate access for technicians to install and service the bladders.
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention.
For example, the liquid storage tank can be divided internally by any number of baffles into any number of discrete liquid storage compartments. The internal compartments need not be the same size as one another. The internal compartments (i.e., the spaces between adjacent baffles) need not be the same size or shape as one another. In some implementations, there are no internal baffles. If there are no baffles, the liquid storage tank may include one internal space and one bladder inside that one internal space.
The absolute and relative size, shape and capacity of each system component can vary.
Any of the communications mentioned herein could be implemented over wired or wireless connections.
The pressure sensors can be virtually any kind of pressure sensors. The compressed air system can vary considerably from what is disclosed herein. The specific configuration of the user interface can vary considerably. The relative positioning of some of the system components can vary.
The pressure sensors do not need to be inside the inflatable bladders. As long as they are in fluid communication with the inside of the inflatable bladders so that they can effectively sense pressure inside the inflatable bladders during inflation, other configurations may be possible. For example, the pressure sensors could be built into solenoid valves (e.g., near or in the solenoid valve outlet ports).
The solenoid valve can be virtually any kind of solenoid valve, or any other kind of valve. In some implementations, the valves can be controlled by something other than a solenoid. For example, the valves can be controlled by air pressure, or hydraulic pressure. In some implementations, the valves can be controlled manually. If the valves are to be controlled manually, the system typically would include a pressure indicator near the valve to indicate the real time pressure inside the associated inflatable bladder and/or a pressure alarm (audible, tactile, and/or visual, etc.) that can indicate to the user operating the manual valve when the target pressure inside the associated inflatable bladder has been reached.
The systems and techniques disclosed herein can be used in a variety of different types of liquid transport applications including in an oil/gas tanker, and smooth bore tank trailers commonly used for transporting food grade products, chemicals, and water.
Moreover, while this specification contains many specific implementation details, these should not be construed as limitations on the scope of any inventions or of what may be claimed, but rather as descriptions of features specific to particular embodiments of particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of subcombinations.
Similarly, while operations are described herein as occurring in a particular order, this should not be understood as requiring that such operations be performed in the particular order disclosed or in sequential order, or that all such operations be performed, to achieve desirable results.
Other implementations are within the scope of the claims.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/844,203, filed May 7, 2019, and entitled INFLATABLE BLADDER SYSTEM FOR BULK LIQUID TRANSPORT. The disclosure of the prior application is incorporated by reference herein in its entirety.
Number | Date | Country | |
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62844203 | May 2019 | US |