Patent ID: 12187385

The above described drawing figures illustrate aspects of the invention in at least one of its exemplary embodiments, which are further defined in detail in the following description. Features, elements, and aspects of the invention that are referenced by the same numerals in different figures represent the same, equivalent, or similar features, elements, or aspects, in accordance with one or more embodiments. More generally, those skilled in the art will appreciate that the drawings are schematic in nature and are not to be taken literally or to scale in terms of material configurations, sizes, thicknesses, and other attributes of an apparatus according to aspects of the present invention and its components or features unless specifically set forth herein.

DETAILED DESCRIPTION

The following discussion provides many exemplary embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus, if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.

While the inventive subject matter is susceptible of various modifications and alternative embodiments, certain illustrated embodiments thereof are shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to any specific form disclosed, but on the contrary, the inventive subject matter is to cover all modifications, alternative embodiments, and equivalents falling within the scope of any appended claims.

Referring first toFIGS.1-3disclosing an exemplary prior art vessel equipped with an air lubrication system (“ALS”)10such as disclosed in U.S. Pat. No. 10,315,729 to McPherson, incorporated herein by reference, one embodiment of the ship hull microbubble system10comprises a ship hull12at least a portion of which extends below a waterline14when the ship hull12is placed in water16. The ship hull12further comprises a bow18in a forward direction and a stern20in an aft direction using the convention common in naval architecture. A ballast pump22is mechanically coupled to a ballast main pipe24which is further connected to a forward peak tank26with a forward peak tank valve28, though it will be appreciated that such forward peak tank26and valve28are optional and merely illustrative and that other ALS10will not necessarily include such devices. The ballast main pipe24is further mechanically coupled to a riser pipe30. Above the ship hull12, the riser pipe30is attached to a venturi injector32which is further attached to a return pipe34that pierces the ship hull12. The return pipe34is attached to a first hull shut off valve36and potentially a second hull shut off valve38. When the forward peak tank valve28is closed the ballast pump22pulls water16from outside the ship hull12into the riser pipe30. From there the water16becomes aerated with air from the venturi injector32that creates an air water mixture further comprising microbubbles40. The air water mixture further comprising the microbubbles40is then simply pushed beneath the ship hull12via the exit in the hull12where it is intersected by the return pipe34, allowing the microbubbles40to somewhat form a boundary layer along the bottom of the hull12, which it will be appreciated makes it relatively easier for the vessel to travel since air is less dense than water; that is, the air water mixture is less dense than the water otherwise would be, and also the surface tension of the foam is less than water, therefore less energy is required for the vessel to move through/over the air water mixture and thus the water16.

Turning now toFIGS.4-6, there are shown partial side and top schematic views of an exemplary embodiment of a foam release apparatus50according to aspects of the present invention as incorporated in an exemplary prior art air lubrication system10operationally installed on a vessel. The apparatus50comprises, in the exemplary embodiment, a chamber52intersected by and in fluid communication with the ALS return pipe34at an upper chamber inlet54formed in the upper wall56of the chamber52and a plurality of sloped release channels60formed within the lower portion of the chamber52somewhat opposite of the ALS return pipe chamber inlet54, each release channel60terminating in a respective release slot68formed in or intersecting the vessel hull12so as to fluidly communicate between the chamber52and the water16beneath the hull12via the release channels60and release slots68. Accordingly, it will be appreciated that the gas or air bubble and water mixture or foam generated by the upstream venturi injector32that passes down through the return pipe34to the foam release apparatus50and specifically the chamber52, or the volume represented by the chamber52, via its inlet54can then stabilize or be conditioned or slowed down pre-release within the chamber or volume52before the foam then passes out of the chamber52through the release channels60and release slots68to the bottom of the hull12so as to form the desired air-water microbubble boundary layer40for reduced drag and improved vessel efficiency. While such an improved foam release apparatus50according to aspects of the present invention is shown and described in connection with a prior art air lubrication system10as per U.S. Pat. No. 10,315,729 to McPherson, it will be appreciated that such foam release apparatus50may be incorporated into or employed in conjunction with any air lubrication system or the like now known or later developed as involving the on-board generation of foam that is to then be discharged or released beneath the vessel hull, such that incorporation of such a foam release apparatus50according to aspects of the present invention in the exemplary prior art air lubrication system10is to be understood as illustrative and non-limiting. Following U.S. Pat. No. 10,315,729 and other such ALS where an air bubble and water foam is generated upstream of the release point of the foam from the hull12, and as an improvement thereover, it is to the benefit of the overall ALS10that the release of foam is conditioned to suit the expected sailing speed(s) and draught(s) of the vessel. Where there is an upstream generation of the foam, its quality and volume can be separated somewhat from the overall performance of the ALS if the transfer and release of the foam is suitably controlled. At a high level, according to aspects of the present invention, beneficially, application of hardware in a foam release apparatus50such as shown and described to control the release of foam from the vessel employs static equipment that is not modified or moved during operation of the ALS10, reducing the cost and complexity of the overall ALS10, it being appreciated that active or movable control of the characteristics (geometry) of the foam release apparatus50and the release channels60and slots68specifically may be possible, however, this would bring complexity and cost to the ALS as well as inevitable reliability issues, as the underside of a ship hull is a harsh environment for an articulated system. Aspects of the present invention are directed to a foam release apparatus50having solid state hardware that is specifically designed for the operational specification of a particular vessel to maximize the performance of its ALS10, meaning that such apparatus50is a static device with no moving parts and no dynamic or control system-based operation, and specifically not being reliant on control of a pump or compressor for effective operation of the inventive foam release apparatus50as part of the ALS10. Such apparatus50hardware or geometry can then be sized or scaled based on the location of foam generation, the quality of the foam generated, and the physical and operational characteristics of the vessel the ALS10and related foam release apparatus50is installed on. Ultimately, the reason it is important to condition the release of a pre-generated foam from an ALS10is that while an unconditioned release of foam under the hull12of the vessel may allow some air lubrication benefit to the vessel, it can also increase turbulence and drag on the vessel. Correct or controlled conditioning of and even somewhat laminar foam release will optimize the benefit of air lubrication for a given foam and a given vessel.

In a bit more detail with continued reference toFIGS.5and6, the exemplary foam release apparatus50again includes a chamber52defined or bounded above and forwardly and rearwardly by upper and side walls56,58, respectively, and below effectively by the release channel lower plate64spaced from and intersecting the vessel hull12and laterally by the release channel side plates66. The upper plate62, not shown inFIG.6for simplicity, the lower plate64, and the vertical side plates66together form the respective release channels60that communicate between the chamber52and the release slots68formed where the release channels60intersect the hull12as openings for the controlled release of foam from the chamber52. Again, the foam enters the chamber52from the upstream air lubrication system10, and its venturi injector32specifically, via the return pipe34that communicates with the chamber52via the inlet54in the chamber upper wall56. Once more, it will be appreciated that such a foam release apparatus50according to aspects of the present invention can take a number of other forms and be scaled or sized to suit various ALS10and vessels without departing from the spirit and scope of the invention. By way of illustration and not limitation, in one exemplary foam release apparatus50according to aspects of the present invention such as shown inFIGS.4-7, the return pipe34may have a nominal diameter D of 200 mm and the overall length L of the chamber52from the base of the forward or bow side plate66to that of the rear or stern side plate66may be 900 mm. If the lateral width W of the chamber52is 2,000 mm, for example, and taking the continuous chamber top and side walls to form a semi-circular width-wise or transverse profile of the chamber52, it follows that the volume of the chamber52in this example is nominally 636,170,000 mm3(V=(π(900 mm)2×1,500 mm)/8), which translates to 0.64 m3or about 636 liters, including the release channels60, though not accounting for the sloped lower plate64. It will be appreciated that such volume in the absolute sense or relative to the ALS10and particularly the size of the venturi injector32and return pipe34thus allows for slowing and conditioning of the foam pre-release from the chamber52and particularly the release slots68via the release channels60. And continuing with the illustrative apparatus50sized as set forth above, the release channel60profile or cross-section Y as defined by the upper, lower, and side plates62,64,66may be nominally 100 mm in both width and height, with the upper and lower plates62,64and thus the release channel60being at a slope or angle S to the bottom of the hull12nominally of ten to twenty degrees (10-20°), such that the length X of the release slot68is then approximately 200 mm and is still nominally 100 mm wide, based on the slanted intersection of the release channel60with the hull12. In the industry, common sizes of venturi injectors32and thus feed pipes34are in the range of 150-600 mm pipe diameter, selected based on pumping rate and pressure and other factors. The main pipe24from the ballast pump22will generally be sized to a water velocity of up to 3 m/sec, such that for example a volumetric flow rate of 340 m3/hr would call for a 200 mm diameter venturi32and pipe34. Ballast flow through standard pipe sizes are thus what determines the volume of foam generated via the venturi injector32at the deck. At relatively high pressure such as might be the case for a ballast pump rating and setup for a relatively small vessel such as a work boat, the typical venturi injector will educt two times (2×) air to water, whereas in other examples such as set forth further below as might be the case with relatively larger, lower pressure ballast systems on relatively larger ships such as tankers, the typical venturi injector32will educt more like one-and-a-third times (1.3×) air to water. To continue with exemplary hard numbers for the illustrated small vessel air lubrication system10and related inventive foam release apparatus50, the volume of foam generated per hour at the deck level consists of 250 m3of water plus 500 m3of air or nominally a total of 750 m3/h at atmospheric pressure. The release point of the foam is the draft of the vessel, such as 6 m below the surface14when the vessel is in ballast. The pressure at 6 m of water is 1.6 atmospheres A (Absolute), so the 500 m3of air is now reduced due to the water pressure under the hull12: 500/1.6=312 m3. Adding the 250 m3of water and the total volume of foam produced and to be discharged is 562 m3/hr. While in cargo the draft is nominally 7 m and thus the pressure of water is 1.7 atmospheres A (Absolute), so the volume of air is 500/1.7=294 m3plus 250 m3of water or 544 m3of foam produced and to be released under the hull12per hour. Taking the nominal volume of the foam release apparatus chamber52to again be 0.64 m3in this example, it follows that the roughly 550 m3/hr (or 0.15 m3/sec) of foam created and discharged by the venturi injector32translates to the foam dwelling within the foam release apparatus chamber52for about four seconds prior to discharge from the release slots68based on such foam creation and volumetric flow rates (0.64 m3/0.15 m3/sec). Of course, this is a bit of an over-simplification and is again based on illustrative round numbers, but the point is made and the benefit of such a foam release apparatus50will be readily understood and appreciated by those skilled in the art, though it should also to be appreciated that any such dwell or residence time of the foam within the chamber or volume52may vary based on a number of factors, principally including but not limited to the size or volume of the chamber52itself or the space between the return pipe34and the release channels and slots60,68, such that the indicated approximately four-second dwell of the foam within the chamber52prior to discharge is to be understood as merely illustrative and non-limiting, and that indeed in other embodiments or contexts a dwell time of one second or less may be appropriate and the foam release apparatus50sized or scaled accordingly. Furthermore, the foregoing regarding any dwell and the resulting more controlled discharge or release of foam beneath the vessel hull12from the release slots68does not account for some of the other physical and fluid dynamics factors at work within the apparatus50such as frictional effects and, in the exemplary embodiment ofFIGS.4-7, the somewhat circuitous or indirect path the foam would take by entering the chamber52from the return pipe34aft and traveling forward along and up the sloped release channel upper plate62to exit the chamber52through the sloped release channels60. In terms of fluid velocities, taking the vessel speed in ballast to be 9 knots or 4.5 m/sec and the vessel speed in cargo to be 8 knots or 4 m/sec, it follows that such would be the approximate velocities at which the foam would be released from the release slots68for a consistent relatively laminar flow across the bottom of the hull12. Taking again the volume of foam produced and thus to be released to be in this example 0.15 m3/sec, it follows that the cross-sectional area through or across which such foam would be released at the desired velocity of 4-4.5 m/sec would be approximately 0.035 m2(0.15 m3/sec/4.25 m/sec), which corresponds to the illustrated example wherein each of the four release channels60has a nominal profile or cross-section of 100 mm×100 mm, which equates to 10,000 mm2or 0.01 m2, there thus being four release channels60having a nominal total cross-sectional area of 0.04 m2(4×0.01 m2). The result as shown in bothFIGS.4and7is a relatively uniform or consistent and even somewhat laminar discharge from the release channels60and slots68of foam or air-water microbubbles40along the vessel hull12, with the aft foam release velocity substantially corresponding to the expected or representative vessel speed, whether in ballast or in cargo, such as an average of 4.25 m/sec in this example. Ultimately, in any and all such versions of a foam release apparatus50“right-sized” for a particular vessel and its expected sailing parameters, the representative vessel speed for purposes of sizing or configuring particularly the release channel(s)60may be taken to be any desired or suitable vessel speed, whether high or low or average or as a percent or proportion of any such anticipated vessel speed(s). Once again, those skilled in the art will appreciate that a variety of other sizes and configurations of such a static or solid state foam release apparatus50according to aspects of the present invention may be employed based on a number of factors without departing from the spirit and scope of the invention, as will be further appreciated from the following alternative non-limiting example.

Referring next toFIGS.8-11, there are shown partial side, top, and bottom schematic views of an alternative exemplary embodiment of a foam release apparatus50according to aspects of the present invention as incorporated in an exemplary prior art air lubrication system or ALS10operationally installed on a vessel, with the exemplary prior art ALS10of U.S. Pat. No. 10,315,729 to McPherson again to be understood as illustrative and non-limiting. The apparatus50once more comprises a chamber52intersected by and in fluid communication with the ALS return pipe34, though here the chamber upper wall56and the release channel upper plate62are contiguous, with the return pipe34passing through the upper plate62defining the upper chamber inlet54. Even so, the overall chamber52perimeter still is bounded or defined at its bottom by the release channel lower plate64and vertically by at least one side wall58. A plurality of sloped release channels60are once again formed within the chamber52, each release channel60bounded or defined by the upper plate62, not shown inFIG.10for simplicity, the lower plate64, and the vertical side plates66and terminating in a respective release slot68formed in or intersecting the vessel hull12so as to fluidly communicate between the chamber52and the water16beneath the hull12via the release channels60and release slots68defining openings for the controlled release of foam from the chamber52. Accordingly, it will again be appreciated that the gas or air bubble and water mixture or foam generated by the upstream venturi injector32that passes down through the return pipe34to the foam release apparatus50and specifically the chamber52via its inlet54can then stabilize or be conditioned pre-release through a holding or dwell time within the chamber52before the foam then passes out of the chamber52in a relatively controlled manner through the release channels60and release slots68to the bottom of the hull12so as to form the desired air-water microbubble boundary layer40for reduced drag and improved vessel efficiency. Once more, it will be appreciated that such a foam release apparatus50according to aspects of the present invention can take a number of other forms and be scaled or sized to suit various ALS10and vessels without departing from the spirit and scope of the invention. By way of further illustration and not limitation, now taking for example a larger tanker or other ship as the vessel on which the ALS10is installed, in one exemplary foam release apparatus50according to aspects of the present invention such as shown inFIGS.8-11, the venturi injector32and return pipe34may have a nominal diameter D of 600 mm based on a relatively low pressure ballast pump rated at 3,000 m3/hr so as to nominally produce foam at the rate of approximately 6,900 m3/hr at the deck at atmospheric pressure and again assuming the venturi injector32will educt roughly one-and-a-third times (1.3×) air to water in such a large waterborne vessel context. Again, the actual release point of the foam is the draft of the vessel, such as for example here for a larger tanker may be 8 m below the surface14when the vessel is in ballast and 13 m below the surface14when the vessel is in cargo. The pressure at 8 m of water is 1.8 atmospheres A (Absolute), so the 3,900 m3of air is now reduced due to the water pressure under the hull12: 3,900 m3/1.8=2,167 m3. Adding the 3,000 m3of water, the total volume of foam produced and to be discharged is thus 5,167 m3/hr with the vessel in ballast in this example. Whereas with the vessel in cargo with a nominal 13 m draft where the pressure is 2.3 atmospheres A (Absolute), it follows that the volume of air is 3,900 m3/2.3=1,696 m3plus 3,000 m3of water or 4,696 m3total volume of foam produced and to be released under the hull12per hour. And taking the vessel speed in ballast to be 13 knots or 6.5 m/sec and the vessel speed in cargo to be 11 knots or 5.5 m/sec, it again follows that such would be the approximate velocities of foam discharge from the release slots68for a consistent relatively laminar flow across the bottom of the hull12. With the average or nominal volume of foam produced and thus to be released in this example of 5,000 m3/hr or about 1.4 m3/sec and the average or nominal representative vessel speed being about 6 m/sec, it follows that the cross-sectional area of the release channels60through or across which such foam would be released at the desired rate of nominally 6 m/sec would be approximately 0.23 m2(1.4 m3/sec/6 m/sec). For illustration and not limitation, once more there are shown four such release channels60and corresponding release slots68intersecting the hull12in the exemplary foam release apparatus50such that the cross-sectional area of each release channel60would then be roughly 0.06 m2(0.23 m2/4). Accordingly, in the alternative exemplary embodiment ofFIGS.8-11, the profile of each release channel60may for example be rectangular with a width Y1of approximately 1,000 mm and a height Y2of approximately 60 mm. This again is a nominal profile or cross-section of each release channel60, noting particularly as best seen inFIG.9that the alternative exemplary embodiment includes a release channel upper plate62that is at a different slope or angle S2than the slope or angle S1of the release channel lower plate64, such that each release channel60is tapered in profile from its inlet within the chamber52to its outlet at the respective release slot68. For example, assuming a roughly ten-degree (10°) slope or angle S1of the release channel lower plate64, the slope or angle S2of the upper plate62may instead be twenty degrees (20°), so that the nominal slope or angle of the release channel60is then fifteen degrees (15°)((20°+10°)/2). Again, those skilled in the art will appreciate that a variety of such geometries and configurations of the foam release apparatus50including the angles of the release channels60, or upper and lower plates62,64, are possible without departing from the spirit and scope of the invention, and specifically whether the release channels60are non-tapered or tapered, it being generally noted that by introducing the foam beneath the hull12at an angle to the hull12, the foam would tend to flow along and form or become part of the boundary layer adjacent to the hull12versus punching through or otherwise disrupting such boundary layer, more about which is said below. Continuing with this alternative exemplary apparatus50, the overall length L of the chamber52from the rear to the forward side plates66may be 4,000 mm and the lateral width W of the chamber52may be 7,000 mm, for example, and taking the width-wise or transverse profile of the chamber52to be rectangular as having an average height Y2between the upper and lower plates62,64of 60 mm and a length of three-fourths the overall length L of the chamber52or 3,000 mm to account for the aft portion of the chamber52generally comprising only the release channels60with gaps therebetween, and taking the width-wise or transverse dimension W of the chamber52to be 7,000 mm, it follows that the volume of the chamber52in this example is nominally 1,260,000,000 mm3(V=(60 mm×3,000 mm×7,000 mm), which translates to 1.26 m3or about 1,260 liters, roughly including the release channels60and somewhat accounting for the sloped upper and lower plates62,64through averaging the height. It again will be appreciated that such volume of the release chamber52in the absolute sense or relative to the ALS10and particularly the size of the venturi injector32and return pipe34thus allows for conditioning of the foam pre-release from the chamber52and particularly the release slots68via the release channels60. And continuing with the illustrative apparatus50sized as set forth above, the release channel60profile or cross-section as defined by the upper, lower, and side plates62,64,66may be nominally 1,000 mm in width Y1and 60 mm in height Y2, with the upper and lower plates62,64and thus the release channel60being at an angle S to the bottom of the hull12, in this example again nominally of fifteen degrees (15°) though with the upper and lower plates62,64being at different angles S1, S2, respectively, such that each release channel60is tapered toward the exit or release slot68and thus the length X of the release slot68is then approximately 60 mm in this example and is still nominally 1,000 mm wide, based on the slanted intersection of the release channel60with the hull12. Once more, this is a bit of an over-simplification and is again based on illustrative round numbers as will be appreciated and understood by those skilled in the art. But for further illustration and not limitation, staying with the exemplary tanker and related ALS10for which a nominal volume of foam produced and thus to be released is approximately 5,000 m3/hr or about 1.4 m3/sec, it follows that here in this example with an approximate chamber or volume52size of 1.26 m3, the dwell time of the foam is about one second or less. Again, those skilled in the art will appreciate that any such dwell time of the foam within the chamber or volume52may vary based on a number of factors, principally including but not limited to the size or volume of the chamber52itself or the space between the return pipe34and the release channels and slots60,68, such that the indicated approximately one second dwell of the foam within the chamber52prior to discharge is again to be understood as merely illustrative and non-limiting, and that indeed in other embodiments or contexts a dwell time of the foam of a second or more may be appropriate and the foam release apparatus50sized or scaled accordingly. The result as shown in bothFIGS.8and11is a relatively uniform or consistent and even somewhat laminar discharge from the release slots68of air-water microbubbles40along the vessel hull12. Once again, those skilled in the art will appreciate that a variety of other sizes and configurations of such a static or solid state foam release apparatus50according to aspects of the present invention may be employed based on a number of factors without departing from the spirit and scope of the invention, as will be further appreciated from the following alternative non-limiting example.

Referring next toFIGS.12-15, there are shown partial side, top, and bottom schematic views of a further alternative exemplary embodiment of a foam release apparatus50according to aspects of the present invention as incorporated in an exemplary prior art air lubrication system or ALS10operationally installed on a vessel such as that disclosed in U.S. Pat. No. 10,315,729 to McPherson that is again to be understood as illustrative and non-limiting. The apparatus50once more comprises a chamber52intersected by and in fluid communication with the ALS return pipe34, here the return pipe34including a bend close to the ship hull12transitioning to a pipe lower section35that is at an angle to the main return pipe34and is substantially aligned with the chamber52and the release channel60and specifically the lower plate64of the release channel60that is again contiguous with or spans both the chamber52and release channel60, with the angled lower section35of the return ‘pipe34thus serving to introduce foam from the ALS10via the return pipe34substantially in-line with the chamber52and the release channel60so as to further reduce any possibility of turbulence being induced in the foam flow. The overall perimeter of the chamber52is again bounded or defined at its bottom by the release channel lower plate64and vertically by opposite side walls58. Above and opposite of the lower plate64an angled upper wall56spanning the opposite side walls58encloses the chamber52. And as best seen inFIG.14, the chamber side walls58are also angled relative to each other such that the chamber's cross-sectional profile is tapered from the chamber inlet54where the return pipe lower section35joins the chamber52; specifically, in the direction of each release channel60the chamber52gets wider as it gets flatter due to the angled chamber upper wall56relative to the planar lower plate64, such that it will be appreciated that the overall cross-sectional profile of the chamber52acts to condition and shape the foam as it flows to the release channels60. As also seen inFIG.14, in the exemplary embodiment there are two separate side-by-side chambers52, one associated with each of two release channels60, such that the foam flow slows and is split across the chambers52. It will be appreciated that such split of the foam flow can be achieved anywhere upstream of the chambers52within the return pipe34as by a “Tee” or otherwise as schematically illustrated inFIG.15, or may be achieved within a unitary single chamber52before being distributed across multiple release channels60as in the other exemplary embodiments ofFIGS.4-11. It is further noted that one or more hull shut off valves36,38may be installed within each such possible “Tee′d” portion of the return pipe34and so be effectively “in parallel,” rather than “in series” as shown inFIG.12, and/or may be installed within the return pipe34upstream of any such “Tee,” and in any case it will be appreciated that any number and arrangement of any such valves36,38may be employed depending on a variety of factors or to suit a particular vessel context as dictated by Classification Society requirements or otherwise, such that the illustrated two valves36,38“in series” is to be understood as exemplary and non-limiting. Regardless, an optional further feature within each release chamber52is a cross-post59to further encourage the spread or distribution of the foam within the chamber52. A plurality of sloped release channels60are once again formed within the foam release apparatus50, again here in the alternative exemplary embodiment one release channel60per chamber52, each release channel60bounded or defined by its upper plate62, not shown inFIG.14for simplicity, the lower plate64, and the vertical side plates66and terminating in a respective release slot68formed in or intersecting the vessel hull12so as to fluidly communicate between the chamber52and the water16beneath the hull12via the release channels60and release slots68defining openings for the controlled release of foam from the chamber52. Accordingly, it will again be appreciated that the gas or air bubble and water mixture or foam generated by the upstream venturi injector32that passes down through the return pipe34, now including its angled lower section35, to the foam release apparatus50and specifically the chamber52via its inlet54can then stabilize or be conditioned pre-release through a holding or dwell time within the chamber52before the foam then passes out of the chamber52in a relatively controlled manner through the release channels60and release slots68to the bottom of the hull12so as to form the desired air-water microbubble boundary layer40for reduced drag and improved vessel efficiency. Once more, it will be appreciated that such a foam release apparatus50according to aspects of the present invention can take a number of other forms and be scaled or sized to suit various ALS10and vessels without departing from the spirit and scope of the invention. By way of further illustration and not limitation, in an exemplary foam release apparatus50according to aspects of the present invention such as shown inFIGS.12-15as might be employed in connection with a vessel such as a car carrier roughly 200 m long having a gross tonnage of approximately 70,000, the return pipe34may have a nominal diameter D1of 400 mm that then tees into two pipes each having a nominal diameter D2of 250 mm including the lower section35with the volume of foam generated per hour at the deck level by the venturi injector32consisting of approximately 1,000 m3of water plus 1,200 m3of air or nominally a total of 2,200 m3/h at atmospheric pressure. The release point of the foam is the draft of the vessel, such as 6 m below the surface14when the vessel is in ballast. The pressure at 6 m of water is again 1.6 atmospheres A (Absolute), so the 1,200 m3of air is now reduced due to the water pressure under the hull12: 1,200/1.6=750 m3. Adding the 1,000 m3of water and the total volume of foam produced and to be discharged is 1,750 m3/hr. While in cargo the draft is nominally 10 m and thus the pressure of water is 2.0 atmospheres A (Absolute), so the volume of air is 1,200/2.0=600 m3plus 1,000 m3of water or 1,600 m3of foam produced per hour and to be released under the hull12per hour. And taking the vessel speed in ballast to be 16 knots or 8 m/sec and the vessel speed in cargo to be 14 knots or 7 m/sec, it follows that such would be the approximate velocities at which the foam would be released from the release slots68for a consistent relatively laminar flow across the bottom of the vessel hull12. Taking the average or nominal volume of foam produced and thus to be released in this example to be 1,675 m3/hr or about 0.46 m3/sec and the average or nominal representative vessel speed being about 7.5 m/sec, it follows that the cross-sectional area of the release channels60through or across which such foam would be released at the desired rate of nominally 7.5 m/sec would be approximately 0.061 m2(0.46 m3/sec/7.5 m/sec). For further illustration and not limitation, once more there are shown inFIG.14two such release channels60and corresponding release slots68intersecting the hull12in the exemplary foam release apparatus50such that the cross-sectional area of each release channel60would then be roughly 0.03 m2(0.06 m2/2). Accordingly, in the further alternative exemplary embodiment ofFIGS.12-15, the profile of each release channel60may for example be rectangular with a width Y1of approximately 500 mm and a height Y2of approximately 60 mm, which equates to 30,000 mm2or 0.03 m2. Those skilled in the art will once again appreciate that a variety of such geometries and configurations of the foam release apparatus50including the angle of the release channels60, or particularly the lower plate, are possible without departing from the spirit and scope of the invention, and specifically whether the release channels60are non-tapered as shown here or are tapered as in other exemplary embodiments, it being generally noted once more that by introducing the foam beneath the hull12at an angle to the hull12, the foam would tend to flow along and form or become part of the boundary layer adjacent to the hull12versus punching through or otherwise disrupting such boundary layer. Continuing with this further alternative exemplary apparatus50, the overall length L of the chamber52from its inlet54to the transition into the respective release channel60may be approximately 1,500 mm, which it will be appreciated includes along its length both an annular pipe section at the chamber inlet54as coupled to the return pipe lower section35and a flattened and tapered transition chute region defined by the contiguous lower plate64below, the opposite angled upper wall56above, and the opposite angled side walls58joining the upper wall56to the lower plate64. More particularly, then, for the annular portion of each chamber52, the length may be approximately 700 mm and its diameter again is 250 mm corresponding to the return pipe34, such that the volume is approximately 34,000,000 mm3(V=(π×(250 mm/2)2×700 mm), which translates to 0.034 m3or about 34 liters. And for the flattened and tapered chute portion, the length may be approximately 800 mm, the height may be approximately 155 mm ((250 mm+60 mm)/2), and the lateral width may be approximately 375 mm ((250 mm+500 mm)/2), such that the volume of each is nominally 46,000,000 mm3(V=(800 mm×155 mm×375 mm), which translates to 0.046 m3or about 46 liters. It follows, then, that the total volume of the chamber52is approximately 0.16 m3((0.034 m3+0.046 m3)×2) or about 160 liters. It again will be appreciated that such volume of the release chamber52in the absolute sense or relative to the ALS10and particularly the size of the venturi injector32and return pipe34thus allows for minimal conditioning of the foam pre-release from the chamber52and particularly the release slots68via the release channels60or is instead configured for somewhat of a steady state throughput. And continuing with the illustrative apparatus50sized as set forth above, the release channel60profile or cross-section as defined by the upper, lower, and side plates62,64,66may again be nominally 500 mm in width Y1and 60 mm in height Y2, with the upper and lower plates62,64and thus the release channel60being at an angle S to the bottom of the hull12, in this example again nominally of fifteen degrees (15°) such that the length X of the release slot68is then approximately 300 mm in this example and is still nominally 500 mm wide, based on the slanted intersection of the release channel60with the hull12. Once more, this is a bit of an over-simplification and is again based on illustrative round numbers as will be appreciated and understood by those skilled in the art. But for further illustration and not limitation, staying with the exemplary car carrier vessel and related ALS10for which a nominal volume of foam produced and thus to be released is approximately 1,675 m3/hr or about 0.46 m3/sec, it follows that here in this example with an approximate volume of the chamber52of 0.16 m3, the dwell time of the foam is under one second or closer to about 0.3 second. Again, those skilled in the art will appreciate that any such dwell time of the foam within the chamber or volume52may vary based on a number of factors, principally including but not limited to the size or volume of the chamber52itself or the space between the return pipe34and the release channels and slots60,68, such that the indicated approximately one-third second dwell of the foam within the chamber52prior to discharge is again to be understood as merely illustrative and non-limiting, and that indeed in other embodiments or contexts a dwell time of the foam of a second or more may once again be appropriate and the foam release apparatus50sized or scaled accordingly. Furthermore, the foregoing regarding any dwell versus a steady somewhat laminar throughput of foam and the resulting more controlled release of foam beneath the vessel hull12from the release slots68does not account for other physical and fluid dynamics factors at work within the apparatus50such as frictional effects and of course includes approximations based on vessel size, speed, draft, etc. Regardless, the result as shown in bothFIGS.12and15is a relatively uniform or consistent and even somewhat laminar release or discharge from the release slots68of air-water microbubbles40along the vessel hull12, which is further contributed to once more by the angle of the release channels60and here even of the aligned bent lower section35of the return pipe34, which angle S of the lower plate64and thus of the release channels60may again be approximately ten to twenty degrees (10-20°). Once again, those skilled in the art will appreciate that a variety of other sizes and configurations of such a static or solid state foam release apparatus50according to aspects of the present invention may be employed based on a number of factors without departing from the spirit and scope of the invention, as will be appreciated from the other non-limiting examples discussed above.

Following the foregoing illustrative discussion of exemplary foam release apparatuses50according to aspects of the present invention, it will be appreciated that the cross-sectional area of the release channel60and its slope or gradient are defining components of the foam release apparatus50and its performance in introducing a relatively smooth and steady flow of foam to the bottom of the vessel hull12, versus shooting out more intermittently or irregularly or agglomerating prior to release (in a sense, belching), with the release chamber52and its release channels60effectively configured to move the foam from the return pipe34to the release slots68at a controlled relatively uniform velocity with minimal turbulence or preference between outlets or release channels60and slots68(if multiple outlets). The volume of foam produced is a function of the driving pump and vessel draught, while the quality of the foam is a function of salt or fresh water and form of the venturi injector. Particularly, sizing of the return pipe34, which is generally a standard size pipe or pipes that match or are larger in cross-section than the venturi injector32, is determined by the quality and quantity of foam generated by the foam generation unit, or venturi injector32in this example, the type of water generating the foam, the layout/pathway and geometry of the return pipe34, and the characteristics, operational and physical, of the vessel the ALS10is installed on. Sizing of the return pipe34should allow the foam generation unit or venturi injector32to work without undue incumbrances (back pressure) and ensure the foam retains the correct quality for effective use in the ALS10, regarding which the size and configuration of the downstream foam release apparatus50is also a factor, and vice versa, with incorrect relative sizing between the return pipe34and the foam release apparatus50potentially leading to incorrect flow characteristics in the foam release apparatus50. Generally, the return pipe34should allow for a foam velocity of between 3 and 12 m/s, potentially in approximate match with the operational characteristics, velocity, draft, etc. of different vessel types and thus foam discharge from the foam release apparatus50via the release channels60and slots68according to aspects of the present invention.

As mentioned previously, by introducing the foam beneath the hull12at an angle to the hull12due to the geometry of the release channels60and slots68, the foam would tend to flow along and form or become part of the boundary layer adjacent to the hull12versus punching through or otherwise disrupting such boundary layer. Particularly, the vertical velocity of foam being released from the foam release apparatus50will primarily be defined by the aftward slope of the release channels60. To some extent this will also be influenced by vessel structure. A gradient of 20-30% or roughly 10-20° will be shallow enough to reduce the vertical velocity of the foam to the point it does not punch through the boundary layer. At this angle, the foam, if introduced at the right aft velocity as set forth herein as somewhat approximating the vessel's representative velocity, will be able to establish itself as a lighter than water layer against the hull per the illustrated air-water microbubbles40along the vessel hull12. The gradient being 20-30% will also not cause the fore-aft opening in the hull12to be too extensive, which of course is important for structural and cost of installation reasons. And the cross-section or profile of the release channels60being relatively uniform even if tapered and each having a minimum length of 500 mm will help to establish a laminar flow for the foam before it is released beneath the hull12into the boundary layer, again reducing turbulence. The length of the release channels60will be influenced by the velocity of the vessel and so the target velocity of the foam (to approximate that of the vessel), with it again being generally noted that commercial vessels big and small tend to travel between 10 and 15 knots while larger container vessels may travel between 18 and 24 knots, for example, while all such applications as well as the onboard ALS10of any such vessel again being accommodated by simply appropriately scaling the respective foam release apparatus50according to aspects of the present invention. Accordingly, aspects of the present invention are directed to the geometry or configuration of the static or steady state foam release apparatus50downstream of the venturi injector32in tuning or “right sizing” the apparatus50relative to the ALS10for optimal foam discharge from the hull outlets60,68, or essentially having the rate of release of the foam somewhat match the expected representative speed of the vessel and the angle of release of the foam be more along the bottom of the vessel, resulting in a relatively more laminar foam release, again directly into the boundary layer so as to improve or reduce the friction of any such boundary layer. This method of specifically determining the depth, width, and length of the release apparatus50in general and each release channel60in particular for a particular vessel and ALS installation (where bubbles are generated before discharge of air from the hull) allows relatively large volumes of foam to be discharged from relatively limited hull penetrations in terms of number and size. In Johannesson the hull penetrations or cavities achieve bubble generation but by design are fully open to the water beneath the hull and shaped to create turbulence or mixing of water with the introduced compressed air within each cavity and so have to be numerous because only a relatively small volume or thickness of bubbles can be generated from each relatively very large hull penetration cavity. And in Armson the multiple sources of air and water are controlled and either driven or “active” or “passive” and result in numerous hull penetrations for discharge across the beam of the vessel. In contrast, in the relatively simple solid state foam release apparatus50according to aspects of the present invention the discharged layer of foam is sufficiently thick to spread across the hull from limited outlets in the hull. This fundamental difference provides significant commercial and operational advantages. Installation is relatively simple, using fractional engineering, design, materials, and labor to support the hull penetrations required by the ALS (to maintain hull strength there are very strict rules governing vessel structures and hull penetrations that call for significant design study and engineering of reinforcement around any hull penetration, which must all be independently reviewed and approved by the Classification Society of the vessel). Also, employing limited penetrations within a relatively small hull surface area, the present system detracts from vessel performance far less if the ALS is not in use as compared to Johannesson and Armson. This is so much of an issue doors are considered on some ALS outlets for selectively closing the ALS outlets when the system is not in use, further adding to the cost, installation, and operational/maintenance burden of the system. The minimal installation burden of the present foam release apparatus50results in a fractional (CAPEX) installation cost (e.g., 20-25%) relative to other air lubrication systems.

It will be further appreciated that any and all such components of the foam release apparatus50may be formed of any suitable material, such as metal or plastic, through any suitable fabrication process, such as molding, casting, machining, welding, stamping, or forming, whether now known or later developed, and may be formed integrally or may be formed separately and then assembled in any appropriate secondary operation employing any assembly technique now known or later developed, including but not limited to fastening, riveting, bolting, bonding, welding, over-molding or coining, or any other such technique now known or later developed. Once again, it will be appreciated by those skilled in the art that a variety of geometries and configurations of a foam release apparatus50according to aspects of the present invention, including but not limited to the release channels60and the release slots68, both in form and number, are possible according to aspects of the present invention without departing from its spirit and scope.

Aspects of the present specification may also be described as the following numbered embodiments:

1. A foam release apparatus for discharging foam formed within an air lubrication system of a water-borne vessel having a hull, the air lubrication system configured to form the foam at a foam volumetric flow rate adjusted for vessel draft and to deliver the pre-formed foam to the apparatus via a return pipe, and the vessel configured to travel through the water at a representative vessel speed, the apparatus comprising: a chamber in fluid communication with the return pipe at a chamber inlet; and a release channel in fluid communication with the chamber and oppositely with a release slot formed by the intersection of the release channel with the hull so as to define an opening in the hull configured for discharge of foam delivered through the return pipe into the chamber and out of the chamber through the release channel and the release slot into the water beneath the hull, the release channel formed having a lower plate at an angle to the hull, wherein a cross-sectional area of the release channel corresponds to the foam volumetric flow rate adjusted for vessel draft divided by the representative vessel speed, further wherein the discharge of foam beneath the vessel through the release slot is along the hull and forms a reduced-friction boundary layer between the hull and the water due to the angle of the lower plate and the cross-sectional area of the release channel and the rate of foam discharge corresponding to the representative vessel speed without the need for any control system-based operation, and further wherein the chamber is not exposed to the opening in the hull and the water beneath the hull due to the configuration of the release channel and release slot and the discharge of foam that is pre-formed within the air lubrication system upstream of the apparatus and delivered to the apparatus via the return pipe.

2. The apparatus of embodiment 1 wherein the angle of the lower plate of the release channel to the hull is in the range of ten to twenty degrees.

3. The apparatus of embodiment 1 or embodiment 2 wherein the angle of the lower plate of the release channel to the hull is fifteen degrees.

4. The apparatus of any of embodiments 1-3 comprising a plurality of release channels and corresponding release slots, wherein a total cross-sectional area of the release channels corresponds to the foam volumetric flow rate adjusted for vessel draft divided by the representative vessel speed.

5. The apparatus of embodiment 4 comprising two release channels and corresponding release slots.

6. The apparatus of embodiment 5 comprising two chambers, one chamber associated with each release channel.

7. The apparatus of embodiment 4 comprising four release channels and corresponding release slots.

8. The apparatus of any of embodiments 4-7 wherein the total cross-sectional area of the release channels is in the range of 0.01 m2to 0.5 m2.

9. The apparatus of any of embodiments 4-8 wherein the total cross-sectional area of the release slots is in the range of 0.01 m2to 2 m2.

10. The apparatus of any of embodiments 1-9 wherein a cross-sectional area of the release slot is the same as or greater than the cross-sectional area of the release channel due to the angle of the lower plate of the release channel.

11. The apparatus of any of embodiments 1-10 wherein the release channel comprises an upper plate opposite of the lower plate and opposite side plates connecting the upper and lower plates to form the enclosed release channel communicating between the chamber and the release slot.

12. The apparatus of embodiment 11 wherein the upper plate is parallel to the lower plate.

13. The apparatus of embodiment 11 wherein the upper plate is at an angle to the lower plate so that the release channel is tapered from the chamber to the release slot.

14. The apparatus of any of embodiments 11-13 wherein the side plates are parallel.

15. The apparatus of any of embodiments 1-14 wherein the chamber is formed having an upper wall and at least one side wall that together with effectively the lower plate of the release channel define a chamber volume.

16. The apparatus of embodiment 15 wherein the ratio of the chamber volume to the foam volumetric flow rate adjusted for vessel draft is one or greater such that the chamber volume allows the foam entering the chamber from the return pipe through the inlet to dwell within the chamber for at least one second before passing out of the chamber through the release channel.

17. The apparatus of embodiment 15 wherein the ratio of the chamber volume to the foam volumetric flow rate adjusted for vessel draft is less than one such that the chamber volume allows the foam entering the chamber from the return pipe through the inlet to pass directly out of the chamber through the release channel and thus to dwell within the chamber for less than one second.

18. The apparatus of any of embodiments 15-17 wherein the chamber volume is in the range of 0.1 m3to 2 m3.

19. The apparatus of any of embodiments 15-18 wherein the inlet is formed in the chamber upper wall opposite of the release channel.

20. The apparatus of any of embodiments 15-19 wherein the inlet is perpendicular to the lower plate of the release channel, whereby the return pipe has a lower section that is parallel to the lower plate of the release channel.

21. The apparatus of any of embodiments 15-20 wherein at least one of the chamber upper wall and side wall is curved.

22. The apparatus of any of embodiments 15-21 wherein at least a portion of the chamber upper wall is at an angle to the lower plate so that the chamber is tapered vertically between the chamber inlet and the release channel.

23. The apparatus of any of embodiments 15-22 wherein the chamber is formed having opposite side walls at an angle to each other so that the chamber is tapered horizontally between the chamber inlet and the release channel.

24. The apparatus of any of embodiments 15-23 wherein a cross-post extends into the chamber from the chamber upper wall.

25. The apparatus of any of embodiments 1-24 wherein the foam volumetric flow rate adjusted for vessel draft is based on the vessel in cargo.

26. The apparatus of any of embodiments 1-24 wherein the foam volumetric flow rate adjusted for vessel draft is based on the vessel in ballast.

27. The apparatus of any of embodiments 1-24 wherein the foam volumetric flow rate adjusted for vessel draft is based on an average of the vessel in cargo and the vessel in ballast.

28. The apparatus of any of embodiments 1-27 wherein the representative vessel speed is based on the vessel in cargo.

29. The apparatus of any of embodiments 1-27 wherein the representative vessel speed is based on the vessel in ballast.

30. The apparatus of any of embodiments 1-27 wherein the representative vessel speed is based on an average of the vessel in cargo and the vessel in ballast.

31. The apparatus of any of embodiments 1-30 wherein the air lubrication system includes a venturi injector.

32. A method of employing a foam release apparatus as defined in any one of embodiments 1-31, the method comprising the steps of: determining a foam volumetric flow rate at atmospheric conditions for the air lubrication system; determining the foam volumetric flow rate adjusted for vessel draft based on the vessel from the foam volumetric flow rate at atmospheric conditions; determining the representative vessel speed for the vessel; and determining the cross-sectional area of the release channel based on the foam volumetric flow rate adjusted for vessel draft divided by the representative vessel speed.

33. The method of embodiment 32 further comprising the step of configuring the foam release apparatus with one or more release channels together having the determined release channel cross-sectional area.

34. The method of embodiment 32 or embodiment 33 further comprising the steps of: forming a release slot in the hull corresponding to each release channel; and installing the foam release apparatus within the vessel adjacent to the hull with the chamber in fluid communication with the return pipe via the chamber inlet and each release channel in fluid communication with the respective release slot.

35. The method of embodiment 34 wherein the step of configuring the foam release apparatus with one or more release channels comprises forming each release channel with a lower plate at an angle to the vessel hull and intersecting the respective release slot.

36. The method of embodiment 35 wherein the step of installing the foam release apparatus within the vessel comprises aligning a lower section of the return pipe with the respective lower plate.

37. The method of any of embodiments 32-36 wherein the step of determining the foam volumetric flow rate adjusted for vessel draft is based on the vessel in cargo.

38. The method of any of embodiments 32-36 wherein the step of determining the foam volumetric flow rate adjusted for vessel draft is based on the vessel in ballast.

39. The method of any of embodiments 32-36 wherein the step of determining the foam volumetric flow rate adjusted for vessel draft is based on the average of the vessel in cargo and the vessel in ballast.

40. The method of any of embodiments 32-39 wherein the step of determining the representative vessel speed is based on the vessel in cargo.

41. The method of any of embodiments 32-39 wherein the step of determining the representative vessel speed is based on the vessel in ballast.

42. The method of any of embodiments 32-41 wherein the step of determining the representative vessel speed is based on the average of the vessel in cargo and the vessel in ballast.

43. The method of any of embodiments 32-42 comprising the further step of determining a volume of the chamber based on the determined foam volumetric flow rate adjusted for vessel draft and the determined release channel cross-sectional area and further based on a desired foam dwell within the chamber from the time the foam enters the chamber to the time it passes out of the chamber into the one or more release channel.

In closing, regarding the exemplary embodiments of the present invention as shown and described herein, it will be appreciated that a foam release apparatus is disclosed and configured for operational installation on a waterborne vessel in conjunction with the vessel's air lubrication system (“ALS”) downstream of the venturi injector or foam generating unit and sized relative to the ALS for optimal foam discharge from the hull outlets, or essentially having the rate of release of the foam somewhat match the expected speed of the vessel and the angle of release of the foam be more along the bottom of the vessel, resulting in a relatively more laminar foam release so as to improve the operation of the ALS. Because the principles of the invention may be practiced in a number of configurations beyond those shown and described, it is to be understood that the invention is not in any way limited by the exemplary embodiments, but instead may take numerous forms based on a variety of factors without departing from the spirit and scope of the invention. It will also be appreciated by those skilled in the art that the present invention is not limited to the particular geometries and materials of construction disclosed, but may instead entail other functionally comparable structures or materials, now known or later developed, without departing from the spirit and scope of the invention.

Certain embodiments of the present invention are described herein, including the best mode known to the inventor(s) for carrying out the invention. Of course, variations on these described embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor(s) expect skilled artisans to employ such variations as appropriate, and the inventor(s) intend for the present invention to be practiced otherwise than specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described embodiments in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Groupings of alternative embodiments, elements, or steps of the present invention are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other group members disclosed herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

In some embodiments, the numbers expressing quantities of components or ingredients, properties such as dimensions, weight, concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the inventive subject matter are to be understood as being modified in some instances by terms such as “about,” “approximately,” or “roughly.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the inventive subject matter are approximations, the numerical values set forth in any specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the inventive subject matter may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

Unless the context dictates the contrary, all ranges set forth herein should be interpreted as being inclusive of their endpoints and open-ended ranges should be interpreted to include only commercially practical values. The recitation of numerical ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value of a numerical range is incorporated into the specification as if it were individually recited herein. Similarly, all lists of values should be considered as inclusive of intermediate values unless the context indicates the contrary.

Use of the terms “may” or “can” in reference to an embodiment or aspect of an embodiment also carries with it the alternative meaning of “may not” or “cannot.” As such, if the present specification discloses that an embodiment or an aspect of an embodiment may be or can be included as part of the inventive subject matter, then the negative limitation or exclusionary proviso is also explicitly meant, meaning that an embodiment or an aspect of an embodiment may not be or cannot be included as part of the inventive subject matter. In a similar manner, use of the term “optionally” in reference to an embodiment or aspect of an embodiment means that such embodiment or aspect of the embodiment may be included as part of the inventive subject matter or may not be included as part of the inventive subject matter. Whether such a negative limitation or exclusionary proviso applies will be based on whether the negative limitation or exclusionary proviso is recited in the claimed subject matter.

The terms “a,” “an,” “the” and similar references used in the context of describing the present invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, ordinal indicators-such as “first,” “second,” “third,” etc.—for identified elements are used to distinguish between the elements, and do not indicate or imply a required or limited number of such elements, and do not indicate a particular position or order of such elements unless otherwise specifically stated.

All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the inventive subject matter and does not pose a limitation on the scope of the inventive subject matter otherwise claimed. No language in the application should be construed as indicating any non-claimed element essential to the practice of the invention.

It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.

While aspects of the invention have been described with reference to at least one exemplary embodiment, it is to be clearly understood by those skilled in the art that the invention is not limited thereto. Rather, the scope of the invention is to be interpreted only in conjunction with any appended claims here or in any patent application claiming the benefit hereof, and it is made clear that the inventor(s) believe that the claimed subject matter is the invention.