TECHNICAL FIELD

[0001] The present disclosure relates to absorbing and releasing thermal energy, particularly relates to methods and systems for heat storage, and more particularly relates to regenerative heat-exchange devices.

BACKGROUND ART

[0002] Thermal energy storage systems may be classified into three types. (1) Sensible heat storage systems in which thermal energy is stored by heating or cooling a storage medium such as water and when the energy is needed, it may be desorbed for use. (2) Latent heat storage systems, where the storage medium may undergo phase transformation and may offer a high energy storage capacity and a long storage period. (3) Thermochemical storage systems, in which the endothermic reaction of a chemical storage medium may be utilized for storing thermal energy. These thermal energy storage systems may store thermal energy for later use in buildings and industrial processes based on their thermal energy demand.

[0003] Zeolites are aluminosilicate minerals of alkali or alkaline earth metals and they include intracrystaline voids that may be partially filled with water molecules. When water molecules are absorbed by a zeolite, absorption heat is released and when water molecules are evaporated or in other words removed from interconnected voids within the zeolite, desorption heat may be stored within the zeolite. This feature may allow utilization of zeolite as thermal storage media particularly in thermal storage systems that utilize solid-gas physical sorption reactions for thermal heat storage.

[0004] However, a thermal storage system utilizing a thermal storage medium such as a zeolite, despite a significantly larger heat storage capacity may be more expensive than sensible heat storage systems that are commercially available for use in different applications. Therefore, latent heat thermal storage systems and thermochemical storage systems are currently economically feasible only for applications with high number and frequency of storage cycles. There is therefore a need for latent heat thermal storage systems and thermochemical storage systems that allow for a cheaper and a more stable storage of thermal energy. There is further a need for new systems and methods for development of smaller and cheaper latent heat thermal storage systems and thermochemical storage systems. SUMMARY OF THE DISCLOSURE

[0005] This summary is intended to provide an overview of the subject matter of the present disclosure, and is not intended to identify essential elements or key elements of the subject matter, nor is it intended to be used to determine the scope of the claimed implementations. The proper scope of the present disclosure may be ascertained from the claims set forth below in view of the detailed description below and the drawings.

[0006] According to one or more exemplary embodiments, the present disclosure is directed to a thermal storage system that may include a perforated vessel, an inner air duct that may be concentrically disposed within the perforated vessel with a gap between a lateral outer surface of the inner air duct and inner surface of the perforated vessel. The lateral outer surface of the inner air duct may be partially perforated. The air duct may be rotatable inside the perforated vessel about a longitudinal axis of the perforated vessel. The exemplary systems may further include a sorbent bed that may include a plurality of sorbent particles disposed within the perforated vessel within the gap. The inner air duct may be configured to allow forcing an air stream to pass through the sorbent bed.

[0007] According to an exemplary embodiment, the exemplary systems may further include an actuator that may be coupled with the inner air duct. The actuator may be configured to cause a rotational movement of the inner air duct about the longitudinal axis of the perforated vessel.

[0008] According to an exemplary embodiment, the exemplary systems may further include a pressurized air source. The inner air duct may be connected in fluid communication with the pressurized air source. In an exemplary embodiment, the pressurized air source may be configured to provide pressurized air with a temperature between 100 °C and 140 °C. In an exemplary embodiment, the pressurized air source configured to provide pressurized air with a temperature between 25 °C and 55 °C.

[0009] According to one or more exemplary embodiments, the perforated vessel may be a cylindrical diffuser with a perforated lateral surface. The inner air-duct may be an elongated rotatable duct with a cam-shaped cross-section. The cam-shaped cross-section may include a base circle and a lobe. In an exemplary embodiment, the inner air-duct may be disposed within the perforated vessel such that the base circle concentric with the cylindrical diffuser.

[0010] According to one or more exemplary embodiments, the lobe of the cam-shaped cross- section may define a protruded section of the inner air-duct, where the protruded section may be perforated. The base circle of the cam-shaped cross-section may define a base section of the inner air-duct. In an exemplary embodiment, the inner air-duct may be disposed within the perforated vessel such that a first air-gap between an outer surface of the protruded section and the inner surface of the perforated vessel smaller than a second air gap between an outer surface of the base section and the inner surface of the perforated vessel.

[0011] In an exemplary embodiment, the plurality of absorbent particles may include a plurality of zeolite particles. In an exemplary embodiment, the plurality of sorbent particles include a plurality of zeolite 13c particles. In an exemplary embodiment, the plurality of zeolite particles may include a plurality of zeolite 13c particles with an average particle size between mesh 30 and mesh 60.

[0012] According to one or more exemplary embodiments, the present disclosure is directed to a method for thermal energy storage. The exemplary method may include concentrically placing a rotatable air duct within a perforated vessel with a gap between an outer surface of the rotatable air duct and an inner surface of the perforated vessel, the air duct comprising a cam-shaped elongated duct with a base section and a protruded perforated section, forming a sorbent bed by pouring a plurality of zeolite particles in the gap, injecting an air stream into the rotatable air duct, the rotatable air duct allowing a radial discharge of the injected air stream via the protruded perforated section through the sorbent bed, and concurrently rotating the rotatable air duct within the perforated vessel.

[0013] According to an exemplary embodiment, concentrically placing the rotatable air duct within the perforated vessel may include placing the rotatable air duct within the perforated vessel such that the base section being concentric with the perforated vessel.

[0014] According to an exemplary embodiment, forming the sorbent bed comprises pouring a plurality of zeolite particles with an average size between mesh 30 and mesh 60 in the gap. In an exemplary embodiment, forming the sorbent bed comprises pouring a plurality of zeolite 13c particles with an average size between mesh 30 and mesh 60 in the gap.

[0015] In an exemplary embodiment, the air stream may have a temperature between 100 °C and 140 °C. In an exemplary embodiment, the air stream has a temperature between 25 °C and 55 °C.

BRIEF DESCRIPTION OF THE DRAWINGS [0016] The drawing figures depict one or more implementations in accord with the present teachings, by way of example only, not by way of limitation. In the figures, like reference numerals refer to the same or similar elements.

[0017] FIG. 1 illustrates a thermal storage system during a charging step, consistent with one or more exemplary embodiments of the present disclosure;

[0018] FIG. 2A illustrates a perspective sectional view of a thermal storage system, consistent with one or more exemplary embodiments of the present disclosure;

[0019] FIG. 2B illustrates a top sectional view of a thermal storage system, consistent with one or more exemplary embodiments of the present disclosure;

[0020] FIG. 3 illustrates an exploded view of a thermal storage system, consistent with one or more exemplary embodiments of the present disclosure;

[0021] FIG. 4 illustrates a top sectional view of a thermal storage system, consistent with one or more exemplary embodiments of the present disclosure;

[0022] FIG. 5 illustrates a lateral view of an inner air duct, consistent with one or more exemplary embodiments of the present disclosure; and

[0023] FIG. 6 is a block diagram of a thermal storage system, consistent with one or more exemplary embodiments of the present disclosure.

DESCRIPTION OF EMBODIMENTS

[0024] In the following detailed description, numerous specific details are set forth by way of examples to provide a thorough understanding of the relevant teachings related to the exemplary embodiments. However, it should be apparent that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.

[0025] The following detailed description is presented to enable a person skilled in the art to make and use the methods and devices disclosed in exemplary embodiments of the present disclosure. For purposes of explanation, specific nomenclature is set forth to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the art that these specific details are not required to practice the disclosed exemplary embodiments. Descriptions of specific exemplary embodiments are provided only as representative examples. Various modifications to the exemplary implementations will be plain to one skilled in the art, and the general principles defined herein may be applied to other implementations and applications without departing from the scope of the present disclosure. The present disclosure is not intended to be limited to the implementations shown, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein.

[0026] The present disclosure is directed to systems and methods for thermal energy storage that utilize a sorbent as a thermal storage medium. In exemplary systems and methods, thermal energy may be stored in the thermal energy storage medium via a solid-gas physical sorption reaction. Exemplary methods may include a storage cycle with a charging step and a decharging step. In exemplary systems, during the charging step a hot air stream may be forced through a sorbent bed in order to remove water molecules from the sorbent and store thermal energy in the sorbent. In the decharging step, an air stream intended to be heated may pass through the charged sorbent and water molecules in the air stream may be adsorbed or otherwise absorbed into the sorbent and sorption heat may be release and heat the air stream. Exemplary systems and methods may facilitate the passage of the air stream through the sorbent bed and allow for an effective heat storage within the sorbent bed and an effective heat release from the sorbent bed by providing an air injection mechanism that may enable forcing an air stream through a thin layer of the sorbent without a need for reducing total amount of sorbent used in exemplary systems.

[0027] FIG. 1A illustrates a thermal storage system 100 during a charging step, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, thermal storage system 100 may include a sorbent bed 102 filled with a sorbent capable of absorbing or otherwise adsorbing liquids. The sorbent may be a material capable of attracting and holding water molecules from the surrounding environment coupled with an exothermic reaction when transitioning from a dehydrated form to a hydrated form. For example, sorbent bed 102 may be filled with a sorbent such as a zeolite. Zeolites have a high heat of adsorption and they are capable of hydrating and dehydrating in several heat storage cycles while maintaining their structural stability. In an exemplary embodiment, during the charging step, heat may be stored in sorbent bed 102 by dehydrating sorbent bed 102 which may be carried out by passing a hot air stream 104 through sorbent bed 102. During dehydration, water molecules may be removed from the sorbent and desorption heat may be stored within sorbent bed 102. [0028] FIG. IB illustrates thermal storage system 100 during a decharging step, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, thermal storage system 100 may be decharged or in other words release the heat that was stored during charging step by passing an ambient air stream 106 through sorbent bed 102. In an exemplary embodiment, during the decharging step, water vapor present in ambient air stream 106 may be adsorbed by the sorbent and the sorption heat released may be utilized for heating ambient air stream 106 to provide a heated air stream 108. In an exemplary embodiment, heated air stream 108 may either be directly used for heating purposes or it may be used in other types of exchangers as the heating fluid. For example, since heated air stream 108 may be dry, it may be utilized in an air-to-air heat exchanger to heat a fresh humid air stream to provide a more comfortable experience for the users.

[0029] FIG. 2A illustrates a perspective sectional view of a thermal storage system 200, consistent with one or more exemplary embodiments of the present disclosure. FIG. 2B illustrates a top sectional view of thermal storage system 200, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, thermal storage system 200 may be an implementation of thermal storage system 100 of FIGs. 1A and IB.

[0030] Referring to FIGs. 2A and 2B, in an exemplary embodiment, thermal storage system 200 may include a perforated vessel 202 and a perforated inner air duct 204 that may be concentrically disposed within perforated vessel 202. In an exemplary embodiment, a sorbent bed 206 may be formed by pouring a plurality of sorbent particles in an air gap between a lateral outer surface of perforated inner air duct 204 and inner surface of perforated vessel 202. An air stream 208 may be fed into thermal storage system 200 along a longitudinal axis 210 of perforated inner air duct 204. In an exemplary embodiment, perforated inner air duct 204 may be a perforated duct with an upper opening 212 and a closed lower end. Air stream 208 may be fed through upper opening 212 of perforated inner air duct 204 and exit perforated inner air duct 204 via lateral perforations 214 and may pass through sorbent bed 206 and exit perforated vessel 202 via lateral perforations 216.

[0031] In an exemplary embodiment, perforated vessel 202 may be a cylindrical diffuser with lateral perforations and perforated inner air duct 204 may be a perforated cylindrical duct that may be concentrically disposed within perforated vessel 202 with an air gap between a lateral outer surface of perforated inner air duct 204 and inner surface of perforated vessel 202. Air stream 208 may be axially fed into perforated inner air duct 204 and it may radially exit perforated inner air duct 204. A plurality of sorbent particles, for example, zeolite particles may be poured into the air gap between perforated inner air duct 204 and perforated vessel 202 to form sorbent bed 206.

[0032] In an exemplary embodiment, during a charging step, air stream 208 may be a hot air stream with a temperature in a range of 100 °C to 140 °C. As the hot air stream is axially fed into perforated inner air duct 204 and it radially exits via lateral perforations 214 of perforated inner air duct 204 through sorbent bed 206, the hot air stream dehydrates sorbent bed 206 and desorption heat may be stored within sorbent bed 206.

[0033] In an exemplary embodiment, during a decharging step, air stream 208 may be an ambient air stream with a temperature in a range of 25 °C to 55 °C. As the ambient air stream is axially fed into perforated inner air duct 204 and it radially exits via lateral perforations 214 of perforated inner air duct 204 through sorbent bed 206, the ambient air stream hydrates sorbent bed 206 and sorption heat may be released and used for heating purposes. Sorption heat may be blown out of thermal storage system 200 via lateral perforations 216 of perforated vessel 202.

[0034] Referring to FIGs. 1A-1B and 2A-2B, in an exemplary embodiment, for an efficient gas-solid contact between the air stream and the sorbent, the thickness of sorbent beds 102 and 206 may be small enough for the air stream to be forced through the entire thickness of the bed to either completely hydrate or dehydrate sorbent beds 102 and 206. On the other hand, the heating capacity and maximum number of heat storage cycles of thermal storage systems 100 and 200 at least partially depend on the amount of sorbent material used in thermal storage systems 100 and 200. Thick sorbent beds 102 and 206 may allow for utilizing a larger amount of sorbent, however, as mentioned above, thick sorbent beds 102 and 206 may not allow for an efficient gas-solid contact between the air stream and the sorbent. According to exemplary embodiments of the present disclosure, exemplary systems and methods for thermal energy storage may include an air injection mechanism that may enable forcing an air stream through a thin sorbent bed without a need for reducing total amount of sorbent used in exemplary systems, which will be described later in this disclosure.

[0035] FIG. 3 illustrates an exploded view of a thermal storage system 300, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, thermal storage system 300 may be an implementation of thermal storage system 100 of FIGs. 1A and IB. Thermal storage system 300 may include a perforated vessel 302 and an inner air duct 304 that may be concentrically disposed within perforated vessel 302 with an air gap between a lateral outer surface 306 of inner air duct 304 and an inner surface 308 of perforated vessel 302. In an exemplary embodiment, inner air duct 304 may include perforations 310 on a portion of lateral outer surface 306. Inner air duct 304 may further include an air inlet opening at a first base end 312 of inner air duct 304 and a second base end 314 of inner air duct 304 may be closed such that inner air duct 304 may allow for forcing an air stream axially into inner air duct 304 along a longitudinal axis 316 of inner air duct 304 and discharging the air stream radially out of inner air duct 304 through perforations 310. In an exemplary embodiment, perforated vessel 302 may be a cylindrical diffuser with lateral perforations with an upper opening 313 and a base end 315.

[0036] FIG. 4 illustrates a top sectional view of thermal storage system 300, consistent with one or more exemplary embodiments of the present disclosure. FIG. 5 illustrates a lateral view of inner air duct 304, consistent with one or more exemplary embodiments of the present disclosure. Referring to FIGs. 4 and 5, in an exemplary embodiment, inner air duct 304 may be an elongated rotatable duct with a cam-shaped cross-section 318. In an exemplary embodiment, cam-shaped cross-section 318 may include a base circle 320 and a protruded portion or otherwise a lobe 322. In an exemplary embodiment, inner air duct 304 may be disposed within perforated vessel 302 such that base circle 320 may be concentric with perforated vessel 302. Extension of base circle 320 along longitudinal axis 316 may form a base section 324 of inner air duct 304 and extension of lobe 322 along longitudinal axis 316 may form a protruded section 326 of inner air duct 304. In an exemplary embodiment, lobe 322 may include flanks 328 and a nose 330. In an exemplary embodiment, nose 330 may include perforations 310 through which air stream may be blown out of inner air duct 304.

[0037] In an exemplary embodiment, the gap between lateral outer surface 306 of inner air duct 304 and inner surface 308 of perforated vessel 302 may be filled with sorbent particles such as zeolite particles to form a sorbent bed 402. In an example, the entire gap between inner air duct 304 and perforated vessel 302 may be filled with sorbent particles. In an exemplary embodiment, protruded section 326 of inner air duct 304 enables reducing a thickness of sorbent bed 402 that is between nose 330 of protruded section 326 and inner surface 308 of perforated vessel 302 by an amount equal to a lobe lift 404 of inner air duct 304. In exemplary embodiments, such a configuration allows for forcing an inlet air stream through a thin layer of sorbent via perforations 310 in order to have a more efficient solid-gas contact. Since the thickness is only reduced where the air is intended to be injected through sorbent bed 402 there is no need to reduce the thickness of the entire sorbent bed 402 and as a result there is no need to reduce the total amount of sorbent in thermal storage system 300.

[0038] In an exemplary embodiment, inner air duct 304 may be rotatable within perforated vessel 302 about longitudinal axis 316. In an example, as inner air duct 304 rotates about longitudinal axis 316, sorbent particles may slide over either one of flanks 328 depending on a direction of the rotational movement of inner air duct 304 and this allows a smooth rotational movement of inner air duct 304 inside sorbent bed 402 among sorbent particles. Inner air duct 304 may rotate within sorbent bed 402 and allow for blowing an air stream through sorbent bed in different directions along the entire periphery of perforated vessel 302 via perforations 310, while protruded section 326 reduces the thickness of a portion of sorbent bed 402 through which the air stream is to be blown. Such a configuration may enable forcing the air stream through a thin sorbent bed without a need for reducing total amount of sorbent used in exemplary systems.

[0039] FIG. 6 is a block diagram of a thermal storage system 600, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, thermal storage system 600 may be an implementation of thermal storage system 300 of FIG. 3. Referring to FIGs. 3, 4 and 6, in an exemplary embodiment, a rotatable air duct 602 similar to inner air duct 304 may be placed within a sorbent bed 604 similar to sorbent bed 402. Rotatable air duct 602 may be coupled to an actuator 606 that may be a rotary actuator such as a rotary motor. Actuator 606 may be configured to drive a rotational movement of rotatable air duct 602 within sorbent bed 604. For example, actuator 606 may drive a rotational movement of inner air duct 304 within perforated vessel 302 about longitudinal axis 316

[0040] In an exemplary embodiment, rotatable air duct 602 may be connected in fluid communication with a pressurized air source 608. Pressurized air source 608 may be configured for providing an air stream in rotatable air duct 602. In an exemplary embodiment, during a charging step, the air stream may be a hot air stream with a temperature in a range of 100 °C to 140 °C. As the hot air stream is axially fed into rotatable air duct 602 and it radially exits rotatable air duct 602 through sorbent bed 604 as shown by arrows 610, 612, the hot air stream dehydrates sorbent bed 604 and desorption heat may be stored within sorbent bed 604. In an exemplary embodiment, sorbent bed 604 may also be heated by an alternative heat source other than a hot air stream, where the alternative heat source may have a temperature in a range of 100 °C to 140 °C.

[0041] In an exemplary embodiment, during a decharging step, the air stream provided by pressurized air source 608 may be an ambient air stream with a temperature in a range of 25 °C to 55 °C. As the ambient air stream is axially fed into rotatable air duct 602 and it radially exits rotatable air duct 602 through sorbent bed 604, the ambient air stream hydrates sorbent bed 604 and sorption heat may be released and used for heating purposes. Sorption heat may radially be blown out of thermal storage system 600 as shown by arrows 610, 612.

[0042] Referring to FIGs. 3 and 5, in an exemplary embodiment, thermal storage system 300 may include an air duct cap 332. Air duct cap 332 may include an outer lip 334 which may be integrally formed with and connected to a recessed portion 336. In an exemplary embodiment, recessed portion 336 may be formed as a short extended part with a similar cross-section with inner air duct 304, for example a cam-shaped cross-section. Recessed portion 336 may be sized and shaped so that it may seat within upper opening of inner air duct 304. Outer lip 334 may be sized and shaped so that it may engage with an upper edge of inner air duct 304. In an exemplary embodiment, air duct cap 332 may further include an upper projecting portion 338 which may be formed as a cylinder concentric with base section 324 that may function as a coupling member by which air duct cap 332 and in turn inner air duct 304 may be coupled to a rotational actuator, such as actuator 606 of FIG. 6. It should be understood that other additional coupling members such as coupling member 340 may further be used to ensure an efficient coupling of inner air duct 304 with actuator 606, however they are not discussed herein for simplicity.

[0043] Referring to FIG. 3, in an exemplary embodiment, thermal storage system 300 may further include a lid 342 that may be sized and shaped so that it may engage and close first base end 312 of perforated vessel 302. In an exemplary embodiment, lid 342 may include a coupling member 344 that may be aligned with upper projecting portion 338. Coupling member 344 may receive upper projecting portion 338 therein. With further reference to FIG. 5, in an exemplary embodiment, base end 315 may further include a central hole 346 connected in fluid communication with a protruded connection port 348 under inner air duct 304. With further reference to FIG. 6, in an exemplary embodiment, central hole 346 may be connected in fluid communication with pressurized air source 608 and air stream provided by pressurized air source 608 may be injected into inner air duct 304 via protruded connection port 348.

[0044] Referring to FIG. 6, in an exemplary embodiment, sorbent bed 604 may be filled with zeolite particles, such as zeolite 13c particles. As mentioned in foregoing sections, zeolites have a high heat of adsorption and they are capable of hydrating and dehydrating in several heat storage cycles while maintaining their structural stability. This makes zeolites good candidates for the sorbent materials that may be utilized in exemplary systems and methods. In an exemplary embodiment, sorbent bed 604 may be filled with zeolite particles, such as zeolite 13c particles with an average particle size between mesh 30 and mesh 60.

[0045] While the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings.

[0046] Unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, and other specifications that are set forth in this specification, including in the claims that follow, are approximate, not exact. They are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain.

[0047] The scope of protection is limited solely by the claims that now follow. That scope is intended and should be interpreted to be as broad as is consistent with the ordinary meaning of the language that is used in the claims when interpreted in light of this specification and the prosecution history that follows and to encompass all structural and functional equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirement of Sections 101, 102, or 103 of the Patent Act, nor should they be interpreted in such a way. Any unintended embracement of such subject matter is hereby disclaimed.

[0048] Except as stated immediately above, nothing that has been stated or illustrated is intended or should be interpreted to cause a dedication of any component, step, feature, object, benefit, advantage, or equivalent to the public, regardless of whether it is or is not recited in the claims.

[0049] It will be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein. Relational terms such as first and second and the like may be used solely to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms“comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by“a” or“an” does not, without further constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0050] The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various implementations. This is for purposes of streamlining the disclosure, and is not to be interpreted as reflecting an intention that the claimed implementations require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed implementation. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.

[0051] While various implementations have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more implementations and implementations are possible that are within the scope of the implementations. Although many possible combinations of features are shown in the accompanying figures and discussed in this detailed description, many other combinations of the disclosed features are possible. Any feature of any implementation may be used in combination with or substituted for any other feature or element in any other implementation unless specifically restricted. Therefore, it will be understood that any of the features shown and/or discussed in the present disclosure may be implemented together in any suitable combination. Accordingly, the implementations are not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.