BACKGROUND

[0001] This disclosure relates generally to heat exchangers and, more particularly, to a heat exchanger having microtubes.

[0002] In recent years, much interest and design effort has been focused on the efficient operation of heat exchangers of refrigerant systems, particularly condensers and evaporators. A relatively recent advancement in heat exchanger technology includes the development and application of parallel flow (also referred to as microchannel or minichannel) heat exchangers as condensers and evaporators.

[0003] Microchannel heat exchangers are provided with a plurality of parallel heat exchange tubes, each of which has multiple flow passages through which refrigerant is distributed and flown in a parallel manner. The heat exchange tubes can be orientated substantially perpendicular to a refrigerant flow direction in the inlet, intermediate and outlet manifolds that are in flow communication with the heat exchange tubes.

SUMMARY

[0004] According to one embodiment, a heat exchanger manifold for use in a heat exchanger having a plurality of microtubes includes a receiving component for supporting and forming a seal about each of the plurality of microtubes and a circuiting component having at least one recessed channel for defining an enclosed flow configuration of a fluid of the heat exchanger. The receiving component is joined and sealed to the circuiting component such that an internal flow passage of the plurality of microtubes is arranged in fluid communication with the at least one recessed channel.

[0005] In addition to one or more of the features described above, or as an alternative, in further embodiments the plurality of microtubes is arranged in fluid communication with said at least one recessed channel.

[0006] In addition to one or more of the features described above, or as an alternative, in further embodiments said at least one recessed channel extends through only a portion of a width or height of said circuiting component.

[0007] In addition to one or more of the features described above, or as an alternative, in further embodiments said at least one recessed channel includes a plurality of recessed channels, said plurality of recessed channels that at least partially define a plurality of fluid passes through the heat exchanger.

[0008] In addition to one or more of the features described above, or as an alternative, in further embodiments said receiving component further comprises a feature for supporting each of the plurality of microtubes.

[0009] In addition to one or more of the features described above, or as an alternative, in further embodiments a cross-section of said feature varies between an inlet side and an outlet side of said receiving component.

[0010] In addition to one or more of the features described above, or as an alternative, in further embodiments said feature is selected from a chamfer and fillet.

[0011] In addition to one or more of the features described above, or as an alternative, in further embodiments said receiving component includes a curable material that is formed with the plurality of microtubes therein.

[0012] According to another embodiment, a heat exchanger manifold for use in a heat exchanger having a plurality of microtubes includes a receiving component including a plurality of openings for selectively receiving and securing the plurality of microtubes. Each of said plurality of openings includes a misalignment accepting feature for receiving the plurality of microtubes within said plurality of openings.

[0013] In addition to one or more of the features described above, or as an alternative, in further embodiments each of the plurality of microtubes is exposed at an outlet side of said receiving component.

[0014] In addition to one or more of the features described above, or as an alternative, in further embodiments a cross-section of said feature varies between an inlet side and an outlet side of said receiving component.

[0015] In addition to one or more of the features described above, or as an alternative, in further embodiments said misalignment accepting feature is selected from an enlarged opening, a chamfer, and countersink.

[0016] In addition to one or more of the features described above, or as an alternative, in further embodiments said receiving component further comprises a first portion having a plurality of openings including a first feature and a second portion having a plurality of openings including a second feature. The first portion and the second portion cooperate to support and secure the plurality of microtubes.

[0017] In addition to one or more of the features described above, or as an alternative, in further embodiments said first portion and said second portion are substantially identical. [0018] In addition to one or more of the features described above, or as an alternative, in further embodiments said first portion and said second portion are movable relative to one another during assembly of the heat exchanger manifold to position the plurality of microtubes within said first feature and said second feature.

[0019] In addition to one or more of the features described above, or as an alternative, in further embodiments said second portion is movable relative to said first portion by a distance of less than or equal to about five times the diameter of each of the plurality of microtubes.

[0020] In addition to one or more of the features described above, or as an alternative, in further embodiments said second portion is rotated relative to said first portion.

[0021] According to yet another embodiment, a heat exchanger manifold for use in a heat exchanger having a plurality of microtubes includes a receiving component for securing an end of the plurality of microtubes. The receiving component is formed from a curable material such that the plurality of microtubes is positioned within the curable material during formation of the receiving component.

[0022] In addition to one or more of the features described above, or as an alternative, in further embodiments each of the plurality of microtubes is exposed at a trailing edge of said receiving component.

[0023] In addition to one or more of the features described above, or as an alternative, in further embodiments a microtube heat exchanger includes a manifold according to any of the preceding claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The subject matter is particularly pointed out and distinctly claimed at the conclusion of the specification. The foregoing and other features, and advantages of the present disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

[0025] FIG. 1 is an example of a conventional vapor compression system;

[0026] FIG. 2 is a perspective view of a parallel flow heat exchanger according to an embodiment of the present disclosure;

[0027] FIG. 3 is a detailed perspective view of a plurality of heat exchanger tubes of a parallel flow heat exchanger;

[0028] FIGS. 4a and 4b are top views of heat exchanger tubes of a parallel flow heat exchanger having varying configurations; [0029] FIG. 5 is a detailed perspective view of another configuration of a plurality of heat exchanger tubes of a parallel flow heat exchanger;

[0030] FIG. 6 is a cross-sectional view of one of the plurality of heat exchanger tubes of a parallel flow heat exchanger;

[0031] FIG. 7 is a cross-sectional view of a manifold of the heat exchanger according to an embodiment;

[0032] FIG. 8 is a cross-sectional view of another manifold of the heat exchanger according to an embodiment;

[0033] FIG. 9 is a front view of a manifold of the heat exchanger according to an embodiment;

[0034] FIG. lOA-C are various views of another manifold of the heat exchanger according to an embodiment;

[0035] FIG. 11 is a perspective view of another manifold of the heat exchanger according to an embodiment; and

[0036] FIG. 12 is a front view of circuiting components of a heat exchanger manifold according to an embodiment.

[0037] The detailed description explains embodiments of the present disclosure, together with advantages and features, by way of example with reference to the drawings.

DETAILED DESCRIPTION

[0038] Problems may occur when using a conventional microchannei heat exchanger within a refrigerant system. As a result of their higher surface density and flat tube construction, microchannei heat exchangers can be susceptible to moisture retention and subsequent frost accumulation. This can be particularly problematic in heat exchangers having horizontally oriented heat exchanger tubes because water collects and remains on the flat, horizontal surfaces of the tubes. This results not only in greater flow and thermal resistance but also corrosion and pitting on the tube surfaces.

[0039] Referring now to FIG. 1, an example of a basic refrigerant system 20 is illustrated and includes a compressor 22, condenser 24, expansion device 26, and evaporator 28. The compressor 22 compresses a refrigerant and delivers it downstream into a condenser 24. From the condenser 24, the refrigerant passes through the expansion device 26 into an inlet refrigerant pipe 30 leading to the evaporator 28. From the evaporator 28, the refrigerant is returned to the compressor 22 to complete the closed-loop refrigerant circuit. [0040] Referring now to FIG. 2, an example of a heat exchanger 40, for example configured for use as either a condenser 24 or an evaporator 28 in refrigerant system 20, is illustrated. As shown, the heat exchanger 40 includes a first manifold 42, a second manifold 44 spaced apart from the first manifold 42, and a plurality of heat exchange microtubes 46 extending generally in a spaced, parallel relationship between the first manifold 42 and the second manifold 44. It should be understood that other orientations of the heat exchange microtubes 46 and respective manifolds 42, 44 are within the scope of the present disclosure. Furthermore, bent heat exchange microtubes and/or bent manifolds are also within the scope of the present disclosure.

[0041] A first heat transfer fluid, such as a liquid, gas, or two phase mixture of refrigerant for example, is configured to flow through the plurality of heat exchanger microtubes 46. While the term "first fluid" is utilized herein, it should be understood that any selected fluid may flow through the plurality of microtubes 46 for the purpose of heat transfer. In the illustrated, non-limiting embodiment, the plurality of microtubes 46 are arranged such that a second heat transfer fluid, for example air, is configured to flow across the plurality of microtubes 46, such as within a space 52 defined between adjacent microtubes 46 for example. As a result, thermal energy is transferred between the first fluid and the second fluid via the microtubes 46.

[0042] The illustrated, non-limiting embodiment of a heat exchanger 40 in FIG. 2 has a single-pass flow configuration. As shown, the first heat transfer fluid is configured to flow from the first manifold 42 to the second manifold 44 through the plurality of heat exchanger microtubes 46 in the direction indicated by arrow B. However, it should be understood that the heat exchanger 40 may be adapted in a variety of ways to achieve a multi-pass flow configuration. Further, although the heat exchanger 40 is illustrated as having only a single tube bank, other configurations having multiple tube banks disposed one behind another relative to the flow of the second heat transfer fluid are within the scope of the present disclosure. In one embodiment, a heat exchanger 40 having multiple tube banks may be formed by forming one or more bends in the plurality of heat exchanger microtubes 46. Furthermore, the first manifold 42 and/or second manifold 44 may be subdivided through an internal partition or may consist of multiple smaller manifolds arranged end-to-end and/or side-by-side, as will be discussed in more detail below.

[0043] Referring now to FIGS. 3-6, the heat exchanger microtubes 46 are illustrated in more detail. As shown, the heat exchanger microtubes 46 have a substantially hollow interior 48 configured to define a flow passage for a heat transfer fluid. As used herein, the term "microtube" refers to a heat exchanger tube having a hydraulic diameter between about 0.2 mm to 1.4 mm, and more specifically, between about 0.4 mm and 1 mm. A wall thickness of the microtubes 46 may be between about .05 mm and .4 mm depending on the method of manufacture. In one embodiment, extruded microtubes 46 may generally have a wall thickness of about .3mm for example. A cross-sectional shape of the microtubes 46 is selected to improve heat transfer between a second heat transfer fluid flowing about the exterior of the microtubes 46 in the direction indicated by arrow A and the first heat transfer fluid flowing through the interior of the plurality of microtubes 46. A cross-sectional shape of the microtubes 46 is also selected to minimize the pressure drop of the first and/or second heat transfer fluid. In the illustrated, non-limiting embodiment, the cross- sectional shape of the outside perimeter of the heat exchanger microtubes 46 is generally rectangular and includes rounded corners. However, it should be appreciated that the microtubes 46 may be constructed having any of a variety of cross-sectional shapes. For example, the cross- sectional shape of the outside perimeter can include but is not limited to a circular, elliptical, rectangular, triangular, or airfoil shape, all of which may have sharp or rounded edges. The shape of the microtubes 46 may be configured to reduce the wake size behind each of the microtubes 46, which decreases pressure drop and improves heat transfer.

[0044] The heat exchanger microtubes 46 are arranged in a plurality of rows 50 such that each row 50 comprises one or more heat exchanger microtubes 46. In embodiments where the rows 50 have multiple heat exchange microtubes 46, each row 50 may have the same, or alternatively, a different number of heat exchange microtubes 46. The heat exchange microtubes 46 within a row 50 are arranged substantially parallel to one another. As used herein, the term "substantially parallel" is intended to cover configurations where the heat exchanger microtubes 46 within a row 50 are not perfectly parallel, such as due to variations in straightness between microtubes 46 and manufacturing tolerances for example. With reference to FIGS. 4A-4B, at least a portion of adjacent microtubes 46 within a layer 50 are separated from one another by a distance such that a gap 52 exists between the microtubes 46 allowing a fluid, such as water condensate for example, to flow there through. In one or more embodiments, one or more ribs 54 may extend between adjacent heat exchange microtubes 46 (FIG. 4A). The ribs can provide stability to the layer 50 and/or can simplify manufacturing. The ribs 54 extending between adjacent heat exchange microtubes 46 may, but need not be substantially aligned with one another. Alternatively, the microtubes 46 may be completely separate from one another, as shown in FIG. 4B. [0045] In yet another embodiment, shown in FIG. 5, the plurality of heat exchanger microtubes 46 within each row 50 may be formed into groups 56, each group 56 consisting of two or more integrally formed heat exchanger microtubes 46. Alternatively, the hollow interior 48 of one or more of the heat exchanger microtubes 46 may be divided to form multiple parallel flow channels within a single heat exchanger microtube 46. At least partial separation between adjacent heat exchanger microtubes 46 or adjacent groups 56 of heat exchanger microtubes 46, however, is generally maintained over a width of the heat exchanger 40.

[0046] As best shown in FIG. 6, each heat exchange microtube 46 has a leading edge 58 and a trailing edge 60. The leading edge 58 of each heat exchanger microtube 46 is disposed upstream of its respective trailing edge 60 with respect to a flow of a second heat transfer fluid (e.g. air) A through the heat exchanger 40. The microtubes 46 may additionally include a first flattened surface 62 and a second, opposite flattened surface 64 to which one or more heat transfer fins 70 (see FIGS. 3 and 5) may be attached.

[0047] Referring again to FIG. 3, a plurality of heat transfer fins 70 may be disposed between and rigidly attached, such as by a furnace braze process for example, to the flattened surfaces 62, 64 (FIG. 6) of the heat exchange microtubes 46 to enhance external heat transfer and provide structural rigidity to the heat exchanger 40. By forming the heat exchanger microtubes 46 with flattened surfaces 62, 64, the contact area between the microtubes 46 and the heat transfer fins 70 is increased which not only improves heat transfer between the microtubes 46 and the fins 70, but also makes the connection between the microtubes 46 and the fins 70 easier to form and gives the connection greater mechanical strength.

[0048] The fins 70 may be formed as layers arranged within the space 66 between adjacent rows 50 of heat exchanger microtubes 46 such that each fin layer is coupled to at least one of the plurality of microtubes 46 within the surrounding rows 50. In an embodiment illustrated in FIG. 3, the fins 70 are lanced or serrated. However, fins 70 of other constructions, such as plain, louvered, or otherwise enhanced are also within the scope of the present disclosure. Inclusion of the plurality of fins 70 provides additional secondary heat transfer surface area where the fins 70 are in direct contact with the adjacent second heat transfer fluid flowing in the direction A.

[0049] The parameters of both the heat exchanger microtubes 46 and the fins 70 may be optimized based on the application of the heat exchanger 40. Accordingly, the heat exchanger 40 provides a significant reduction in both material and refrigerant volume compared to conventional microchannel heat exchangers, while allowing condensate to drain between adjacent heat exchanger microtubes 46 and through openings formed in the fins 70. In addition, the microtube design allows for flexibility in the spatial arrangement between adjacent microtubes 46 along their length. For example, flow axes of a plurality of microtubes 46 can converge within a manifold 42, 44 (e.g., the microchannel tubes 46 can be non-parallel along portions of the heat exchanger). In comparison, the spatial arrangement between microchannels in a multiport microchannel tubes can be fixed (e.g., such as when the multiport tube is extruded with a fixed cross-section and thus a fixed channel spacing). Thus, in at least this way, the manifolds 42, 44 can be made smaller, the space 52 can be made larger, the distance that the microtubes 46 extend into the manifold can be reduced, or a combination including at least one of the foregoing can be realized in comparison to multiport microchannel tubes (e.g., flat multiport tubes) which can correspondingly yield a reduction in the overall size of the heat exchanger 40.

[0050] With reference now to FIGS. 7-12, various embodiments of a header 80, such as header 42 or 44 of the heat exchanger 40, are illustrated and described in more detail. As shown, the header 80 includes a first receiving component 82 for fluidly coupling to each of the plurality of individual microtubes 46 and a second circuiting component 84 for forming an enclosed flow path to define the configuration of the plurality of passes of the heat exchanger 40.

[0051] The receiving component 82 may use any of a variety of processes to secure the ends 47 of a plurality of microtubes 46. In an embodiment, best illustrated in FIG. 7, an enlarged opening, chamfer, fillet, countersink, or other misalignment accepting feature 86 having a width or height greater than that of the microtube 46 is formed adjacent an inlet side 88 of the receiving component 82. The misalignment accepting feature 86 may be formed by removing material from the receiving component 82, such as via a milling or machining operation. The misalignment accepting feature 86 may gradually reduce in size, as shown, to a dimension that forms a clearance fit with the microtube 46 to facilitate insertion of the microtube 46 into an opening 90 associated with the misalignment accepting feature 86. In embodiments where the receiving component 82 is formed from a piece of sheet metal, as shown in FIG. 8, the misalignment accepting features 86 and the plurality of openings 90 may be formed, such as using a stamping or piercing operation for example to form a countersink, or other misalignment feature 86.

[0052] Alternatively, with reference now to FIG. 9, all or a part of the receiving component 82 may be formed from a curable material, and the ends 47 of the plurality of microtubes 46 may be arranged therein before initiating the curing process. For example, a mold 92, such as a trough large enough to receive the ends 47 of a plurality of microtubes 46 within one or more rows 50 for example, may be filled with a potting or other curable material 94 (e.g., thermoset polymeric material such as epoxy or the like). After the curable material 94 has hardened, the mold 92 used to retain the curable material 94 during the curing process may be removed and any excess material or length of the microtubes 46 may be removed as needed to allow for joining with a circuiting component.

[0053] In yet another embodiment, the receiving component 82 includes two similar or substantially identical portions 96a, 96b oriented in an overlapping relationship. In the example illustrated in FIG. 10A, the portions 96a, 96b are rectangular plates; however embodiments where the portions 96a, 96b are another configuration, such as cylindrical tubes receivable in a nested concentric configuration as shown in FIGS. 10B and IOC for example, are also within the scope of the disclosure. As shown, each of the portions 96a, 96b includes an opening 98a, 98b associated with a corresponding microtube 46 of the heat exchanger 40. Each of the openings 98a, 98b is specially shaped and may have at least one dimension generally equal to or slightly greater than the width and/or height of the microtube 46. The microtubes 46 are inserted into the first receiving portion 96a oriented in a first configuration and the microtubes 46 are then inserted in to the second receiving portion 96b in a second configuration. In an embodiment, in a first configuration for receiving the microtubes 46, the first and second portions 96a, 96b are misaligned. To restrict movement of the microtubes 46, the first and second receiving portions 96a, 96b are moved, i.e. rotated or translated, relative to one another. In an embodiment, the second portion 96b is movable relative to said first portion 96a by a distance of less than or equal to about five times the diameter of each of the plurality of microtubes 46. In embodiments where the first and second portion are rotatable, the relative rotation is less than or equal to about 180 degrees, and more specifically between about 5 degrees and about 45 degree. The relative movement of the first and second portions 96a, 96b causes the corresponding openings 98a, 98b to cooperate to form a tight seal about the microtubes 46. The two portions 96a, 96b may then be joined to each other and to the microtubes 46 to achieve a strong, leak-tight seal at all joints via brazing or an adhesive material for example.

[0054] Referring again to FIG. 7, the second circuiting component 84 is located adjacent an outlet side 100 of the receiving component 82 to define a flow path for the fluid within the heat exchanger microtubes 46. In embodiments where the receiving component 82 and the circuiting component 84 are separate, they may be fixedly or removably connected to one another via any suitable means, such as via brazing or a thermoset material for example. However, it should be understood that embodiments where the receiving component 82 and the circuiting component 84 of a manifold are integrally formed, such as via an additive manufacturing operation for example, are also contemplated herein.

[0055] In its simplest form, the circuiting component 84 has a generally hollow interior 102, as shown in FIG. 11, arranged in fluid communication with and configured to receive a fluid flow from the plurality of microtubes 46. For heat exchangers 40 having a more complex flow pattern, however, one or more pockets or recessed channels 104 may be formed in the circuiting component 84. As shown in FIG. 7, the recessed channels 104 typically extend through only a portion of the thickness of the circuiting component 84. As a result, when the circuiting component 84 is mounted adjacent the receiving component 82, the recessed channel 104 is generally sealed between the trailing edge 100 of the receiving component 82 and a trailing edge 106 of the circuiting component 84.

[0056] At least one of the microtubes 46 of the heat exchanger 40 is arranged in fluid communication with each recessed channel 104. The shape and configuration of each recessed channel 104 may vary based on a variety of factors including the number of microtubes 46 fluidly coupled thereto, the total number of passes of the heat exchanger 40, and the type of fluid within the heat exchanger 40 for example. To accommodate this variation, the circuiting component 84 may be formed via any suitable manufacturing process including, but not limited to, molding, casting, machining, stamping, and additive manufacturing for example.

[0057] The manifold 80 illustrated and described herein allows for easier installation of the plurality of microtubes 46. In addition, the circuiting component 84 of the headers allows for complex circuiting of all or a portion of the microtubes 46, and may be used to create any number of passes that extend in any direction relative to the first and second fluid.

[0058] Embodiment 1: A heat exchanger manifold for use in a heat exchanger having a plurality of microtubes comprising: a receiving component for supporting and forming a seal about each of the plurality of microtubes; and a circuiting component having at least one recessed channel for defining an enclosed flow configuration of a fluid of the heat exchanger, wherein said receiving component is joined and sealed to said circuiting component such that an internal flow passage of the plurality of microtubes is arranged in fluid communication with said at least one recessed channel.

[0059] Embodiment 2: The heat exchanger manifold of embodiment 1, wherein the plurality of microtubes is arranged in fluid communication with said at least one recessed channel. [0060] Embodiment 3: The heat exchanger manifold of any of embodiments 1 and 2, wherein said at least one recessed channel extends through only a portion of a width or height of said circuiting component.

[0061] Embodiment 4: The heat exchanger manifold of any of embodiments 1-3, wherein said at least one recessed channel includes a plurality of recessed channels, said plurality of recessed channels that at least partially define a plurality of fluid passes through the heat exchanger.

[0062] Embodiment 5: The heat exchanger manifold of any of embodiments 1-4, wherein said receiving component further comprises a feature for supporting each of the plurality of microtubes.

[0063] Embodiment 6: The heat exchanger manifold of embodiment 5, wherein a cross-section of said feature varies between an inlet side and an outlet side of said receiving component.

[0064] Embodiment 7: The heat exchanger manifold of embodiment 5, wherein said feature is selected from a chamfer and fillet.

[0065] Embodiment 8: The heat exchanger manifold of any of embodiments 1-7, wherein said receiving component includes a curable material that is formed with the plurality of microtubes therein.

[0066] Embodiment 9: A heat exchanger manifold for use in a heat exchanger having a plurality of microtubes comprising: a receiving component including a plurality of openings for selectively receiving and securing the plurality of microtubes, each of said plurality of openings including a misalignment accepting feature for receiving the plurality of microtubes within said plurality of openings.

[0067] Embodiment 10: The heat exchanger manifold of embodiment 9, wherein each of the plurality of microtubes is exposed at an outlet side of said receiving component.

[0068] Embodiment 11: The heat exchanger manifold of embodiments 9 and 10, wherein a cross-section of said feature varies between an inlet side and an outlet side of said receiving component.

[0069] Embodiment 12: The heat exchanger manifold of any of embodiments 9-11, wherein said misalignment accepting feature is selected from an enlarged opening, a chamfer, and countersink.

[0070] Embodiment 13: The heat exchanger manifold of embodiment 9, wherein said receiving component further comprises: a first portion having a plurality of openings including a first feature; and a second portion having a plurality of openings including a second feature, wherein said first portion and said second portion cooperate to support and secure the plurality of microtubes.

[0071] Embodiment 14: The heat exchanger manifold of embodiment 13, wherein said first portion and said second portion are substantially identical.

[0072] Embodiment 15: The heat exchanger manifold of any of embodiments 13 and 14, wherein said first portion and said second portion are movable relative to one another during assembly of the heat exchanger manifold to position the plurality of microtubes within said first feature and said second feature.

[0073] Embodiment 16: The heat exchanger manifold of any of embodiments 13-15, wherein said second portion is movable relative to said first portion by a distance of less than or equal to about five times the diameter of each of the plurality of microtubes.

[0074] Embodiment 17: The heat exchanger manifold of any of embodiments 13-16, wherein said second portion is rotated relative to said first portion.

[0075] Embodiment 18: A heat exchanger manifold for use in a heat exchanger having a plurality of microtubes comprising: a receiving component for securing an end of the plurality of microtubes, the receiving component being formed from a curable material such that the plurality of microtubes is positioned within the curable material during formation of the receiving component.

[0076] Embodiment 19: The heat exchanger manifold of embodiment 19, wherein each of the plurality of microtubes is exposed at a trailing edge of said receiving component.

[0077] Embodiment 20: A microtube heat exchanger including a manifold according to any of the preceding claims.

[0078] While the present disclosure has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the present disclosure is not limited to such disclosed embodiments. Rather, the present disclosure can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate in spirit and/or scope. Additionally, while various embodiments have been described, it is to be understood that aspects of the present disclosure may include only some of the described embodiments. Accordingly, the present disclosure is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.