LIQUID RING ROTOR

Abstract

Liquid ring systems are known for compressing gasses. However, known systems include seals on moving surfaces that require high precision manufacturing. A liquid ring rotor is provided and methods of operating the same. A liquid ring rotor for a liquid ring system is provided and comprises a shaft, and one or more fluid diverting members. The shaft includes a hollow interior portion, the hollow interior portion having a first opening and a second opening, the second opening disposed in a surface that extends along a length of the shaft and spaced apart from the first opening in the length of the shaft, wherein the shaft is configured to enable a working fluid to pass along the shaft through the hollow interior portion between the openings.

Claims

1. A liquid ring rotor, for a liquid ring system, comprising: a shaft with a hollow interior portion, the hollow interior portion having a first opening and a second opening, the second opening disposed in a surface that extends along a length of the shaft and spaced apart from the first opening in the length of the shaft, wherein the shaft is configured to enable a working fluid to pass along the shaft through the hollow interior portion between the openings; and one or more fluid diverting members extending at least partially radially from the shaft and fixedly attached thereto, wherein the one or more fluid diverting members are configured to divert fluid along the shaft when rotated about the shaft in use.

2. The liquid ring rotor of claim 1, wherein the one or more fluid diverting members are configured to divert fluid along the shaft with one or more helical flow paths around the shaft when the one or more fluid diverting members are rotated about the shaft in use, and/or wherein the fluid diverting members comprise a first set of fluid diverting members and a second set of fluid diverting members, the first set of fluid diverting members configured to divert a working fluid with a first helical flow path, and the second set of fluid diverting members configured to divert the working fluid with a second helical flow path that mirrors the rotational direction and/or direction of propagation of the first helical flow path, and/or wherein the first and second sets of fluid diverting members are configured to divert the working fluid toward the second opening or the first and second sets of fluid diverting members are configured to divert the working fluid away from the second opening.

3. The liquid ring rotor of claim 1, wherein the one or more fluid diverting members comprise: a first plurality of plates, each extending at least partially radially from the shaft and fixedly attached to the shaft between the first opening and the second opening, wherein each plate of the first plurality of plates includes at least one plate opening therethrough, and wherein each plate of the first plurality of plates is spaced apart from other plates of the first plurality of plates; a first vane set comprising one or more vanes disposed between adjacent plates of the first plurality of plates; and a first chamber set comprising at least one chamber, wherein a first chamber of the chamber set is bounded at least by a pair of adjacent plates of the first plurality of plates and one or more vanes of the first vane set, the first chamber configured to admit liquid through a first chamber opening disposed further from the shaft than the at least one plate opening of each plate, and wherein a plate opening of the at least one plate opening of each of the pair of adjacent plates opens into the first chamber.

4. The liquid ring rotor of claim 1, wherein the one or more fluid diverting members comprise: a second plurality of plates, each extending at least partially radially from the shaft and fixedly attached to the shaft in positions further from the first opening than the second opening is from the first opening, wherein each plate of the second plurality of plates includes at least one plate opening therethrough, and wherein each plate of the second plurality of plates is spaced apart from other plates of the second plurality of plates; and a second vane set comprising one or more vanes, wherein each vane of the second vane set is impermeable to the working fluid, and wherein each vane of the second vane set extends between adjacent plates of the second plurality of plates and the shaft; and/or wherein the at least one plate opening of the first plurality of plates has an overlapping area of zero with the at least one plate opening of another plate of the first plurality of plates and the at least one plate opening of the second plurality of plates has an overlapping area of zero with the at least one plate opening of another plate of the second plurality of plates.

5. The liquid ring rotor of claim 1, wherein the second plurality of plates is arranged to mirror an arrangement of the first plurality of plates about the second opening.

6. The liquid ring rotor of claim 1, wherein the first plurality of plates includes at least three plates, and a first spacing between a first plate of the first plurality of plates and a second plate of the first plurality of plates is different to a second spacing between the second plate of the first plurality of plates and a third plate of the first plurality of plates.

7. The liquid ring rotor of claim 1, wherein the vanes of each vane set are connected to the adjacent plates and the shaft to prevent the working fluid from bypassing said connections.

8. The liquid ring rotor of claim 1, comprising a heat exchanger with a first port arranged to exchange the working fluid with the first opening of the shaft, such that in use the working fluid is able to pass between the hollow interior portion of the shaft and the heat exchanger, and wherein the heat exchanger is fixedly connected to the shaft to rotate with the shaft in use.

9. The liquid ring rotor of claim 8, the rotor further comprising: a companion shaft with a companion hollow interior portion, the companion hollow interior portion having a companion first opening and a companion second opening, the companion second opening disposed in a surface that extends along a length of the companion shaft and spaced apart from the companion first opening in the length of the companion shaft, wherein the companion shaft is configured to enable the working fluid to pass along the companion shaft through the companion hollow interior portion between the openings, and wherein the companion first opening is arranged to exchange working fluid with a second port of the heat exchanger that is in fluid communication with the first port of the heat exchanger, such that in use the working fluid is able to pass between the companion hollow interior portion and the heat exchanger, and wherein the heat exchanger is fixedly connected to the companion shaft to rotate with the companion shaft in use; a companion first plurality of plates, each extending at least partially radially from the companion shaft and fixedly attached to the companion shaft between the companion first opening and the companion second opening, wherein each plate of the companion first plurality of plates includes at least one plate opening therethrough, and wherein each plate of the companion first plurality of plates is spaced apart from other plates of the companion first plurality of plates and each plate opening of the companion first plurality of plates has an overlapping area of zero with the plate openings of another plate of the companion first plurality of plates; and a companion first vane set comprising one or more vanes, wherein each vane of the companion first vane set is impermeable to the working fluid, and wherein each vane of the companion first vane set extends between adjacent plates of the companion first plurality of plates and the shaft.

10. The liquid ring rotor of claim 9, the rotor further comprising: a companion second plurality of plates, each extending at least partially radially from the companion shaft and fixedly attached to the companion shaft in positions further from the companion first opening than the companion second opening is from the companion first opening, wherein each plate of the companion second plurality of plates includes at least one plate opening therethrough, and wherein each plate of the companion second plurality of plates is spaced apart from other plates of the companion second plurality of plates and each plate opening of the companion second plurality of plates has an overlapping area of zero with the plate openings of another plate of the companion second plurality of plates, and wherein the companion second plurality of plates is arranged to mirror an arrangement of the companion first plurality of plates about the companion second opening; a companion second vane set comprising one or more vanes, wherein each vane of the companion second vane set is impermeable to the working fluid, and wherein each vane of the companion second vane set extends between adjacent plates of the companion second plurality of plates and the companion shaft; and/or wherein the companion first plurality of plates includes at least three plates, and a first spacing between a first plate of the companion first plurality of plates and a second plate of the companion first plurality of plates is different to a second spacing between the second plate of the companion first plurality of plates and a third plate of the companion first plurality of plates.

11. A liquid ring system arrangement, the arrangement comprising: the liquid ring rotor of claim 10; a vessel configured to enclose a container and a companion container; the container disposed inside the vessel and arranged to surround each edge of the plates of the first plurality of plates and each edge of the plates of the second plurality of plates, and wherein the container is configured to retain a sealing liquid; the companion container disposed inside the vessel and arranged to surround each edge of the plates of the companion first plurality of plates and each edge of the plates of the companion second plurality of plates, and wherein the companion container is configured to retain a sealing liquid; and an insulation wall disposed inside the vessel between the container and the companion container to reduce the direct flow of working fluid and/or thermal energy therebetween, such that a majority of working fluid and/or thermal energy passed between the container and the companion container is passed via the heat exchanger.

12. The liquid ring system arrangement of claim 11, wherein the vessel encloses one or more reservoirs to collect sealing liquid spillages from the container and/or companion container in use, and wherein a sealing liquid return system is configured to transport the spillage into the container and/or companion container.

13. A method for operating a liquid ring rotor comprising: providing the liquid ring rotor of claim 1; and causing the liquid ring rotor to rotate about the shaft using a drive system.

14. A method for operating a liquid ring system arrangement comprising: providing the liquid ring system arrangement of claim 11; and causing the liquid ring rotor to rotate about the shaft using a drive system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0077] FIG. 1 shows a three-dimensional schematic representation of multiple plates 102A-D with associated vane sets of a rotor 100 for use in a liquid ring system.

[0078] FIG. 2 shows an example liquid ring system arrangement that includes two opposing liquid ring systems.

[0079] FIG. 3 shows an example liquid ring system arrangement that includes a liquid system arrangement with two companion liquid ring systems each having two opposing liquid ring systems.

DETAILED DESCRIPTION

[0080] The present invention will be described with respect to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. Each drawing may not include all of the features of the invention and therefore should not necessarily be considered to be an embodiment of the invention. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

[0081] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other sequences than described or illustrated herein. Likewise, method steps described or claimed in a particular sequence may be understood to operate in a different sequence.

[0082] Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other orientations than described or illustrated herein.

[0083] It is to be noticed that the term comprising, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression a device comprising means A and B should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

[0084] Similarly, it is to be noticed that the term connected, used in the description, should not be interpreted as being restricted to direct connections only. Thus, the scope of the expression a device A connected to a device B should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means. Connected may mean that two or more elements are either in direct physical or electrical contact, or that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other. For instance, wireless connectivity is contemplated.

[0085] Reference throughout this specification to an embodiment or an aspect means that a particular feature, structure or characteristic described in connection with the embodiment or aspect is included in at least one embodiment or aspect of the present invention. Thus, appearances of the phrases in one embodiment, in an embodiment, or in an aspect in various places throughout this specification are not necessarily all referring to the same embodiment or aspect, but may refer to different embodiments or aspects. Furthermore, the particular features, structures or characteristics of any one embodiment or aspect of the invention may be combined in any suitable manner with any other particular feature, structure or characteristic of another embodiment or aspect of the invention, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments or aspects.

[0086] Similarly, it should be appreciated that in the description various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Moreover, the description of any individual drawing or aspect should not necessarily be considered to be an embodiment of the invention. Rather, as the following claims reflect, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

[0087] Furthermore, while some embodiments described herein include some features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form yet further embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0088] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0089] In the discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

[0090] The use of the term at least one may mean only one in certain circumstances. The use of the term any may mean all and/or each in certain circumstances.

[0091] The use of the term expand may mean decompress or increase in volume in some examples. Similarly, the use of the term expandable may mean decompressible or increasable in volume in some examples.

[0092] The expression at least partially radially may refer to one or more features that extend from or converge to a common central point, common central area, or common central feature. For example, features arranged at least partially radially may all be directed toward a shaft, or extend from a shaft. It is to be understood that features arranged at least partially radially include the specific example of being arranged radially. The use of the term radially may refer to a feature that extends in at least one dimension from its centre of mass or geometric centre to a nearest portion of a common central point, a nearest portion of a common central area, or a nearest portion of a common central feature.

[0093] The principles of the invention will now be described by a detailed description of at least one drawing relating to exemplary features. It is clear that other arrangements can be configured according to the knowledge of persons skilled in the art without departing from the underlying concept or technical teaching, the invention being limited only by the terms of the appended claims.

[0094] FIG. 1 shows a three-dimensional schematic representation of multiple plates 102A-D with associated vane sets of a rotor 100 for use in a liquid ring system. Dashed lines show edges that may not be visible if, for example, the vanes or plates are opaque. Some vanes are not shown between the plates to aid intelligibility.

[0095] The first plate 102A may be joined to one or more of the second plate 102B, the third plate 102C and the fourth plate 102D to create a multistage liquid ring system. Each plate 102A-D that extends at least partially radially from a shaft 113 may retain an orientation that is fixed relative to each other plate in the plurality of plates 102A-D. The first plate 102A and the second plate 102B may form a pair of plates. The second plate 102B and the third plate 102C may form a pair of plates. The third plate 102C and the fourth plate 102D may form a pair of plates. Each pair of plates may be spaced apart by a distance, wherein the distance between each pair of plates may increase, decrease, or stay the same for each successive pair of plates. Each pair of plates may have an associated vane set comprising one or more vanes disposed therebetween. Each pair of plates and the associated vane set therebetween may form a stage 121, 122, 123 or, more specifically, a first stage 121, a second stage 122 and a third stage 123. A first vane set may be disposed between the first plate 102A and the second plate 102B, a second vane set may be disposed between the second plate 102B and the third plate 102C, and a third vane set may be disposed between the third plate 102C and the fourth plate 102D. Each stage 121, 122, 123, may comprise a chamber set.

[0096] Each vane set of the rotor 100 for use in a liquid ring system may be arranged to match the orientation of every other vane set. An edge of each vane of a first vane set may overlap an edge of each vane of a second vane set. Alternatively, each vane set of the rotor 100 may be offset, by a vane offset, from an adjacent vane set, such as a vane set of a preceding stage. Each vane set may be offset, e.g. in at least two dimensions, from the adjacent vane sets to provide a helical path through the plates for the working fluid in use. Each plate opening of a plurality of plates may be offset, e.g. in at least two dimensions, from the plate openings of adjacent plates of the plurality of plates to provide a helical path through the plates for the working fluid in use.

[0097] By way of example, the rotor may be configured to enable working fluid to enter the rotor through plate opening 104A and follow a left-handed helical pattern through the rotor as the rotor rotates about the longitudinal axis 113 of the shaft. The rotor may be rotated such that plate opening 104A enters the sealing liquid before plate opening 104B. When rotating in this direction, the rotor is moving clockwise when viewed from the end which includes plate opening 104A. As the sealing liquid reduces the size of the chamber associated with plate openings 104A and 104B, the working fluid is compressed and then pushed out of the first stage 121, through plate opening 104B, to the second stage 122. As the sealing liquid reduces the size of the chamber associated with plate openings 104B and 104C, the working fluid is further compressed and then pushed out of the second stage 122, through plate opening 104C, to the third stage 123. As the sealing liquid reduces the size of the chamber associated with plate openings 104C and 104D, the working fluid is further compressed and then pushed out of the third stage 123 through plate opening 104D.

[0098] The plate openings may be configured to enable a right-handed helical pattern of working fluid to flow therethrough. For example, by moving plate opening 104A closer to vane 108A than vane 109A, and plate opening 104B to the other side of vane 109B. When the rotor is moving clockwise when viewed from the end which includes plate opening 104A, working fluid would now be ejected away from the plurality of plates from plate opening 104A, rather than plate opening 104D.

[0099] The helical path maximises the path length of the working fluid through the system and, in this way, maximises the change in volume of the working fluid provided by a rotor of a given size in a liquid ring system.

[0100] The vane set may be arranged to provide an impeller, or more specifically, a vaned impeller configured to move a working fluid through the plates as the vanes rotate with the rotor. The vanes may be fixedly connected to the shaft 113. Each vane of the vane set may be directed toward a common point on the first and/or second plate. For example, each vane of the vane set may be arranged at least partially radially from a shaft. Each vane of the vane set may be directed toward a central point on a surface of the first and/or second plate. Vanes of the vane set may branch out from or be directed towards a common point and/or common centre of a surface of the first and/or second plate. Each vane of the vane set may be directed towards a shaft.

[0101] Each vane of the vane set may be formed from a sheet of material. Each vane of the vane set may be thin relative to its length and/or width. For example, the length and/or width of the vane may be at least 10, 100, or 1000 times larger than the thickness of the vane. Each vane of the vane set may have a profile along the surface of at least one plate that is straight, curved, or any other shape. Each vane of the vane set may have a twisted profile, a curved profile, or any other profile. Alternatively, or additionally, the profile of each vane may be twisted such that a profile of an edge of the vane in contact with the first plate is different to a profile of an edge of the vane in contact with second plate. Each vane may comprise a non-porous surface, non-porous faces, or no porous faces. Each vane may be formed from a heat-resistant plastic, a metal, ceramic and/or a composite material.

[0102] A first chamber may be formed between two adjacent vanes 108A, 109A, the first plate 102A and the second plate 102B. A second chamber may be formed between two adjacent vanes 108B, 109B, the second plate 102B and the third plate 102C. aforementioned first and second chambers are successive chambers, because a plate opening 104B associated with the first chamber is also associated with the second chamber. For example, the first chamber may exchange a working fluid with the second chamber in use. Each successive chamber may act, in use, to further change the pressure of a working fluid. That is, if the first chamber is configured to increase the pressure of the working fluid, the second chamber through which the working fluid travels will further increase the pressure of the working fluid output from the first chamber. Alternatively, if the first chamber is configured to decrease the pressure of the working fluid, the second successive chamber of the rotor through which the working fluid travels will further decrease the pressure of the working fluid output from the first chamber.

[0103] A vane face, or face of a vane, is surface of the vane which is exposed to the chamber. Each vane of the vane set may have two faces. The two vane faces may be the two largest surfaces of a vane. For example, each vane of the vane set may have a forward face and a rearward face. The forward face may face the direction of rotation or face a direction closer to the direction of rotation than against the direction of rotation. The rearward face may face against the direction of rotation or may face a direction that is closer to against the direction of rotation than the direction of rotation.

[0104] Each plate 102A-D may have one or more plate openings to enable working fluid to pass therethrough. The plate openings may prevent working fluid from passing therethrough when they are submerged in a sealing liquid of a liquid ring system. The plate openings of each adjacent plate of a plurality of plates, or each plurality of plates of the rotor 100, may be arranged with an overlapping area of zero. For example, the plate opening 104A of the first plate 102A may not overlap the plate opening 104B of the second plate 102B and plate opening 104B of the second plate 102B may not overlap with the plate opening 104C of the third plate 102C. However, plate openings of non-successive plates may overlap, for example, the plate openings 104A and 104C of the first and third plates 102A and 102C may overlap. In some examples, the plate opening position may alternate between plates. For example, the plate opening(s) 104A of the first plate 102A may overlap the plate opening(s) 104C of the third plate 102C and plate opening(s) 104B of the second plate 102B may overlap the plate opening(s) 104D of the fourth plate 102D.

[0105] A complete liquid ring system, in use, includes a hollow cylinder of sealing liquid created by a rotating container. This hollow cylinder has a longitudinal axis that runs parallel to the longitudinal axis of the shaft 113 with an offset. In some examples, the offset and/or maximum inner diameter of the hollow cylinder of sealing liquid may be predetermined. Alternatively, or additionally, a given rotor may be configured to operate with a predetermined range of offsets and/or a predetermined range of inner diameters of the hollow cylinder of sealing liquid. For example, the offset range may be based in part on the plate opening size and/or position. The predetermined range of inner diameters of the hollow cylinder of sealing liquid may be based in part on the plate shape, plate size, and plate opening positioning.

[0106] The rotor 100 may be rotated at a first speed about the longitudinal axis of the shaft 113. Furthermore, at a stage of the rotation, the second plate opening 104B may emerge from the predetermined maximum inner diameter of a hollow tube of sealing liquid and be configured to allow working fluid to leave the first chamber enter the second chamber through said second plate opening 104B, wherein the first chamber and second chamber are successive chambers. Successive chambers may be configured to operate at alternate compression stages. For example, the rotor may have three successive chambers, the first chamber, the second chamber and a third chamber. The first chamber may fill with a working fluid at the same stage in the rotation of the rotor 100 as the third chamber.

[0107] The rotor may be configured to ensure that, in use, the sealing liquid does not migrate along the rotor with the working fluid. The rotor may be configured to ensure that, in use, there is relatively little force, or no overall force, exerted by said rotor on the sealing liquid in a direction perpendicular to the plates of the rotor.

[0108] As described above, an effective chamber may encompass different sub-chambers depending on the rotational stage of the rotor. For example, the effective chamber may encompass a chamber of stages 121 and 122 in one rotational stage and encompass a chamber of stages 122 and 123 in a second rotational stage. Rotational stages of the rotor refer to rotational positions of the rotor when it is rotated about the axis 113, about which the rotor is configured to be rotated.

[0109] FIG. 2 shows an example liquid ring system arrangement that includes two opposing liquid ring systems.

[0110] The first liquid ring system shown includes a first plurality of plates 202a, and the second liquid ring system includes a second plurality of plates 202b. The first plurality of plates 202a and second plurality of plates 202b form part of a liquid ring rotor. The system includes a drive system 223 to rotate the rotor, such as a motor. The drive system 223 may be directly connected to the rotor. For example, the drive system 223 may be directly connected to a shaft of the rotor. The liquid ring rotor comprises a shaft 225 and a first plurality of plates 202a. Between each adjacent plate of the first plurality of plates 202a and/or each adjacent plate of the second plurality of plates 202b there is a vane set, as described in relation to FIG. 1.

[0111] The shaft 225 is supported by shaft bearings 224. The shaft bearings 224 are in direct contact with the shaft 225 and may be disposed at one or more positions along the shaft 225. The shaft includes a hollow interior portion 205, a first opening 204 and a second opening 206. The first opening 204 is in fluid communication with the second opening 206. That is, fluid can flow freely between the first opening 204 and the second opening 206 through the hollow interior portion 205 of the shaft 225.

[0112] The example liquid ring system arrangement includes a container 215 that retains sealing liquid therein. In use, the container 215 is rotated such that the sealing liquid forms a hollow three-dimensional shape that covers the internal surface of container 215, wherein the hollow region is defined by the sealing liquid surface 218. The container 215 is in direct contact with the container bearings 216. One or more container bearings 216 may be present along the container 215, such as a container bearing 216 at each end of the container 215. The container 215 may be rotated by the same drive system 223 as the liquid ring rotor and with the same number of revolutions per minute as the liquid ring rotor, for example, using a power transfer system comprising one or more of a gear, a belt, and a chain. In some examples, the container 215 may be rotated by the same drive system 223 as the liquid ring rotor using the sealing liquid to transfer power therebetween.

[0113] The example shown in FIG. 2 may include two opposing liquid ring systems each operated as a liquid ring compressor that, for example, compresses working fluid toward the space between the first plurality of plates 202a and the second plurality of plates 202b. In this example, working fluid at a relatively low pressure enters the container 215 as shown with the flow arrows 231 and 232. The rotor is rotated such that the working fluid is compressed toward the second opening 206. The resulting increase in pressure of the working fluid at the second opening 206 causes the working fluid to enter the second opening 206, as shown by flow arrow 233, and pass through the hollow interior portion 205 of the shaft 225 to the first opening 204. The working fluid proceeds to pass out of the first opening, as shown by flow arrow 222, at a higher pressure than the pressure at which it entered the container 215.

[0114] The example shown in FIG. 2 may include two opposing liquid ring systems each operated as a liquid ring expander. The flow of working fluid in this example would be the reverse of the flow shown in direction of arrows 222, 231, 232 and 233. In this example, the working fluid enters the first opening 204 at a relatively high pressure and proceeds through the hollow interior portion 205 to the second opening 206. The rotor is rotated such that the working fluid is pulled away from the second opening 206 and out toward the ends of the container 215. Working fluid then leaves the container 215 at a relatively low pressure.

[0115] The two opposing liquid ring systems work synergistically with the plurality of plates of each system fixed to the same shaft by configuring each system to have a flow path through the plates in a direction opposite to the other, wherein the direction of the flow path is controlled by the locations of the plate openings of each plate. The flow path through the plates may be a helical flow path. The helical flow path can be a left-handed helical flow path or a right-handed helical flow path. One of the two opposing liquid ring systems is configured to have a left-handed helical flow path through the plates, and the other of the two opposing liquid ring systems is configured to have a right-handed helical flow path through the plates such that the liquid ring systems work synergistically, for example, to compress a working fluid to between the systems or expand a working fluid from between the systems.

[0116] It may be understood that a left-handed helical flow path is a mirrored path of a right-handed helical flow path. By way of example, if following a clockwise path from a first end of the helix around the helix moves away from said first end of the helix, then it is a right-handed helix; if following an anticlockwise path from a first end of the helix around the helix moves away from said first end of the helix, then it is a left-handed helix. A right-handed helix cannot be turned to look like a left-handed one unless it is viewed in a mirror, and vice versa.

[0117] FIG. 3 shows an example liquid ring system arrangement that includes a liquid system arrangement with two opposing liquid ring systems and two companion liquid ring systems. In some examples, this liquid ring system arrangement may operate as a heat pump with opposing compressors on one side and opposing expanders on the companion side.

[0118] Two opposing liquid ring systems may refer to a liquid ring system and a liquid ring system that opposes said liquid ring system. A liquid ring system that opposes another liquid ring system may be configured to work together with the other liquid ring system to provide a synergistic effect, for example, each system of the opposing liquid ring systems may be a compressor, each system of the opposing liquid ring systems may be an expander, or each system of the opposing liquid ring systems may be a pump.

[0119] It may be understood that FIG. 3 includes two of the example liquid ring system arrangements shown and described in relation to FIG. 2 combined to operate as a liquid ring system arrangement. In this example, the liquid system arrangement includes two opposing liquid ring systems, and a companion set of two opposing liquid ring systems. The liquid system arrangement includes a single rotor that includes two opposing liquid ring systems, and a companion set of two opposing liquid ring systems. The arrangement may be suitable for being driven by a drive system 223 that does not include more than one motor.

[0120] A vessel 301 is provided. The vessel is a fully enclosed vessel configured to retain working fluid. The vessel is sealed to prevent the escape of gas. In some examples, the vessel 301 is only exposed to relatively low pressure working fluid as the liquid ring systems are configured to interact with the sealing liquid in use to constrain the working fluid pressurised by the liquid ring system arrangement.

[0121] The vessel 301 includes a divider 303 between the first end 302 and the second end 304. The second end 304 may also be referred to as the companion end 304. The divider 303 may be an insulation wall 303 configured to reduce the conductive heat transfer between the first end 302 and the companion end 304. The divider 303 extends from the vessel 301 toward the heat exchanger 326 and is arranged to minimise working fluid passing between the first end 302 and the opposing end 304 without passing through the heat exchanger 326. The divider 303 may cover more than 95% of the cross sectional area of the vessel around the liquid ring rotor between the first end 302 and the companion end 304. The divider 303 may comprise one or more portions, each portion being fixedly attached to only one of the vessel 301 or the liquid ring rotor. In some examples, the divider 303 may be fixedly attached to the heat exchanger 326. The divider 303 may include a gap between the portions, between the divider 303 and the vessel 301 or between the divider 303 and the heat exchanger 326, for example, to permit the liquid ring rotor to rotate freely. The gap may cover no more than 5% of the cross sectional area of the vessel. A small gap in the divider does not significantly degrade performance, as both sides of the divider are at a similar pressure that is relatively low. Relatively high pressure working fluid is largely constrained within the hollow interior portion of each shaft 205, 305, the heat exchanger, and between the pluralities of plates 202a, 202b, 309a, 309b.

[0122] In some examples the liquid ring system arrangement may operate as a heat pump. The vessel 301 includes a hot end 302 and a cold end 304. In use, the temperature of the hot end 302 may be high relative to the cold end 304. The hot end 302 includes a liquid ring system configured to compress working fluid into the shaft, in the direction indicated by flow arrow 233. Heat is released from the working fluid as the working fluid is compressed by opposing liquid ring compressors 328. The cold end 304 is configured to receive compressed working fluid from the hot end 302 through the shaft in the direction indicated by flow arrow 334. The cold end 304 includes opposing liquid ring expanders 329 configured to expand, or decompress, the working fluid. Heat is absorbed by the working fluid as the working fluid is expanded or decompressed.

[0123] The heat exchanger 326 is fixedly attached to the rotor to rotate with the shafts 225, 327 of the rotor. The working fluid compressed by the opposing liquid ring compressors 328 passes through the hollow interior portion 205 to a first port of a heat exchanger 326. The compressed working fluid passes from the second port of the heat exchanger 326 to the opposing liquid ring expanders 329 via hollow interior portion 305. The opposing liquid ring expanders 329 decompress the working fluid, which pushes the working fluid away from the opposing liquid ring expanders (as shown by flow arrows 335 and 336), to a third port of the heat exchanger 326 (as shown by flow arrow 337) then out of a fourth port of the heat exchanger 326 to the hot end 302 (as shown by flow arrow 338). From here the working fluid may continue to cycle through the liquid ring system arrangement by entering the container 215 as shown by flow arrows 231 and 232.

[0124] The first port of the heat exchanger 326 is in fluid communication with a second port of the heat exchanger 326. The third port of the heat exchanger 326 is in fluid communication with the fourth port of the heat exchanger 326. The first and second ports of the heat exchanger 326 are not in fluid and/or liquid communication with the third and fourth ports of the heat exchanger 326. Fluid passing between the first and second ports of the heat exchanger 326 are in thermal communication with fluids passing between the third and fourth ports of the heat exchanger 326, wherein thermal communication is provided by a heat exchange material, such as a thermal conductor or a heat exchange membrane.

[0125] As it passes through the heat exchanger 326, the pressurised working fluid may be cooled by the heat exchanger 326 to cool it at a constant pressure, which also reduces the volume of the pressurised working fluid. The heat exchanger 326 transfers a portion of the heat energy of the compressed working fluid compressed by the liquid ring system of the hot end 302 to the decompressed working fluid exiting the cold end 304. In this way, the heat exchanger 326 increases the efficiency of the heat pump. The efficiency is increased as the heat exchanger 326 enables the working fluid entering the liquid ring system arrangement of the cold end 304 to capture more heat due to a decreased temperature, whilst simultaneously providing additional heat energy to the working fluid to be compressed at the hot end 302 of the system. The working fluid entering the liquid ring system of the cold end 304 may capture more heat due to a decreased temperature that increases a temperature differential with an environment surrounding of the cold end 304. The working fluid may provide additional heat energy when compressed at the hot end 302 of the system due to an increased temperature differential with an environment surrounding of the hot end 304.

[0126] The companion set of two opposing liquid ring systems system includes a companion container 313 that retains sealing liquid therein. In use, the companion container 313 is rotated such that the sealing liquid forms a hollow three-dimensional shape that covers the internal surface of companion container 313, wherein the hollow region is defined by the sealing liquid surface 318. The companion container 313 is in direct contact with the companion container bearings 314. One or more companion container bearings 314 may be present along the companion container 313, such as companion container bearing 314 at each end of the companion container 313. The companion container 313 may be rotated by the same drive system 223 as the liquid ring rotor and with the same number of revolutions per minute as the liquid ring rotor, for example, using a power transfer system comprising one or more of a gear, a belt, and a chain. In some examples, the companion container 313 may be rotated by the same drive system 223 as the liquid ring rotor using the sealing liquid to transfer power therebetween.

[0127] Liquid ring system containers, such as the container 215, or the companion container 313, may be caused to rotate in use by the movement of sealing liquid as the rotor rotates in said sealing liquid, e.g., due to viscous forces.

[0128] The companion shaft 327 is supported by companion shaft bearings 324. The shaft bearings 324 are in direct contact with the companion shaft 327 and may be disposed at one or more positions along the companion shaft 327. The companion shaft 327 includes a hollow interior portion 305, a first opening 307, and a second opening 306. The first opening 307 of the companion shaft 327 is in fluid communication with the second opening 306 of the companion shaft. That is, fluid can flow freely between the first opening 307 and the second opening 306 through the hollow interior portion 305 of the companion shaft 327.

[0129] A first companion plurality of plates 309a, otherwise referred to as a third plurality of plates 309a, is fixedly attached to the companion shaft 327. In some examples, a second companion plurality of plates 309b, otherwise referred to as a fourth plurality of plates 309b, is fixedly attached to the companion shaft 327. Between each adjacent plate of the first companion plurality of plates 309a and/or each adjacent plate of the second companion plurality of plates 309b there is a vane set including at least one vane (not shown).

[0130] The rotor may comprise the shaft 225, the companion shaft 327, the heat exchanger 326, and four pluralities of plates 202a, 202b, 309a, 309b. In some examples, references to a shaft, or the shaft of the rotor, may include the shaft 225 and the companion shaft 327.

[0131] When power is applied to the drive system 223 in use, the rotor rotates and moves heat from the cold end 304 of the vessel 301 into the hot end 302 of the vessel 301. The heat is moved by compressing the working fluid in the hot end 302 to release heat and increase the hot end temperature, and expanding the working fluid in the cold end 304 to cause the working fluid to absorb heat and decrease the temperature of the environment surrounding the cold end 304 of the vessel 301. The working fluid cycles repeatedly around inside the vessel 301. The divider 303 and heat exchanger 326 may provide at least some insulation between the hot end 302 and the cold end 304 to enable the efficient movement of heat from a relatively cold environment surrounding the cold end 304 into a relatively hot environment surrounding the hot end 302.

[0132] The transfer of heat between the cold end 304 of the vessel and the relatively cold environment surrounding the cold end 304 may be facilitated by a thermal energy conveyancer. The transfer of heat between the hot end of the vessel and the relatively hot environment surrounding the hot end 302 may be facilitated by a thermal energy conveyancer. A thermal energy conveyancer may include one or more of a heatsink, liquid cooling system, or Peltier cooling system.