VALVE ARRANGEMENT

Abstract

Liquid ring systems are known for compressing gasses. However, known systems include moving surfaces that require high precision manufacturing. The invention provides a valve arrangement for a liquid ring system comprising: a plurality of plates; a vane set; and a chamber set that comprises at least one chamber, wherein a first chamber of the chamber set comprises: a first valve, disposed on a first plate of the plurality of plates, which is configured to be closer to the first face of a first vane of the vane set than the second face of the second vane of the vane set; and a second valve, disposed on a second plate, which is configured to be closer to the second face of the second vane than the first face of the first vane.

Claims

1. A valve arrangement for a liquid ring system comprising: a plurality of plates arranged to face each other, comprising a first plate and a second plate spaced apart by a first distance, and each plate of the plurality of plates comprising at least one valve, wherein each of the plurality of plates is configured to be rotatable about a first axis at a first speed; a vane set disposed between the first plate and the second plate, each vane of the vane set having a first face and a second face; a chamber set comprising at least one chamber, wherein a first chamber of the chamber set is bounded by the first plate, the second plate, the first face of a first vane of the vane set, and the second face of a second vane of the vane set, wherein each vane of the vane set is impermeable to a working fluid and each vane extends between the first plate and the second plate to prevent the working fluid from bypassing the vane, in use, when the working fluid is disposed between the first plate and the second plate; and wherein the first chamber of the chamber set comprises: a first valve, disposed on the first plate, wherein at least a portion of the first valve is configured to be closer to the first face of a first vane of the vane set than the second face of the second vane of the vane set; and a second valve, disposed on a second plate, wherein at least a portion of the second valve is configured to be closer to the second face of the second vane than the first face of the first vane.

2. The valve arrangement of claim 1, wherein the plurality of plates comprise a third plate that faces an opposite side of the second plate to the first plate, the third plate being spaced apart from the second plate by a second distance, wherein a third valve is disposed on the third plate and a second vane set disposed between the second plate and third plate, each vane of the second vane set having a first face and a second face, and/or wherein the first, second and third valves are rotationally spaced about the first axis such that the second valve does not overlap the first valve or the third valve.

3. The valve arrangement of claim 2, wherein the second distance is greater than or smaller than, but not equal to, the first distance.

4. The valve arrangement of claim 2, wherein the plurality of plates includes a first number of plates and the chamber set includes a second number of chambers, the first number of plates being at least one more than the second number of chambers.

5. The valve arrangement of claim 1, wherein the first chamber is further configured to be bounded, in use, by a sealing fluid at a perimeter of the first plate and a perimeter of the second plate, and/or wherein the at least one valve is arranged on each plate of the plurality of plates such that, in use, it is submerged through a predetermined maximum inner diameter of a hollow tube of sealing fluid during the rotation of the plurality of plates, said arrangement being based on said predetermined maximum inner diameter and a predetermined offset between a center of said predetermined maximum inner diameter and the first axis.

6. The valve arrangement of claim 1, wherein the first vane of the vane set, and the second vane of the vane set are the same vane.

7. The valve arrangement of claim 1, wherein each valve of the at least one valve comprises an opening in the plate and/or an open-ended tubular member.

8. The valve arrangement of claim 1, wherein each valve of the at least one valve comprises a non-return valve and/or a pressure sensitive valve.

9. A liquid ring system that comprises: the valve arrangement of claim 1 disposed within a tubular vessel; the tubular vessel comprising a working fluid inlet at a first end of the tubular vessel and a working fluid outlet at a second end of the tubular vessel, wherein the tubular vessel is configured to retain a sealing fluid and to be rotated at a second speed that exerts a centrifugal force on the sealing fluid and wherein the axis of rotation of the tubular vessel is a second axis that is offset from the first axis by a first offset; and wherein the liquid ring system is configured such that, in use, an edge of each plate of the plurality of plates is submerged in the sealing fluid such that a working fluid is only able to pass within the tubular vessel, between the working fluid inlet and working fluid outlet, through the at least one valve of each plate of the plurality of plates.

10. The liquid ring system of claim 9, wherein liquid ring system is a liquid ring pump, a liquid ring compressor, a liquid ring decompressor and/or a liquid ring expander.

11. The liquid ring system of claim 9, wherein within the tubular vessel the working fluid is less dense than the sealing fluid as measured by at least one known measurement technique.

12. The liquid ring system of claim 9, wherein the working fluid is a gas and the sealing fluid is a liquid.

13. The liquid ring system of claim 9, wherein the first speed is the same as the second speed.

14. The liquid ring system of claim 9, wherein a hollow tube of sealing fluid having a predetermined maximum inner diameter is formed in use by the rotation of the tubular vessel and at least one of the first valve and second valve is arranged to be submerged in the hollow tube of sealing fluid at any stage of rotation of the valve arrangement, based on said predetermined maximum inner diameter of the sealing fluid and the first offset, to prevent a reverse flow of working fluid through the vessel.

15. A method for operating a liquid ring system, comprising: rotating the tubular vessel of the liquid ring system of claim 9 about the second axis at a second speed; applying working fluid, from a source of working fluid, at a first pressure to the working fluid inlet; rotating the valve arrangement about the first axis at the first speed to cause a change in pressure within the first chamber by: submerging the second valve into the sealing fluid; emerging the first valve from the sealing fluid to expose the first valve to the working fluid, such that the working fluid fills the chamber at the first pressure; enclosing the first chamber within the bounds of the first plate, the second plate, the first face of a first vane of the vane set, and the second face of a second vane of the vane set, by preventing reverse flow of working fluid through the first valve using at least one of a backflow prevention valve, a preceding sealed chamber of the valve arrangement in pressure communication with the first chamber or by submerging the first valve in the sealing fluid; adjusting a penetration depth of the first chamber into the sealing fluid, based at least in part on the offset of the second axis from the first axis, to adjust a volume of the first chamber; and emerging the second valve from the sealing fluid.

16. A method for operating a valve arrangement in a liquid ring system, comprising: rotating the valve arrangement of claim 1 about the first axis at the first speed to cause a change in pressure within the first chamber by: submerging the second valve through a predetermined maximum inner diameter of a hollow tube of sealing fluid; emerging the first valve from the predetermined maximum inner diameter of the hollow tube of sealing fluid; enclosing the first chamber within the bounds of the first plate, the second plate, the first face of a first vane of the vane set, and the second face of a second vane of the vane set, by preventing, in use, a reverse flow of working fluid through the first valve using at least one of a backflow prevention valve, a preceding sealed chamber of the valve arrangement in pressure communication with the first chamber or by submerging the first valve through the predetermined maximum inner diameter of the hollow tube of sealing fluid; adjusting a penetration depth of the first chamber into the predetermined maximum inner diameter of the hollow tube of sealing fluid, based at least in part on a predetermined offset between a center of said predetermined maximum inner diameter and the first axis; and emerging the second valve from the predetermined maximum inner diameter of the hollow tube of sealing fluid.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0072] The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.

[0073] FIG. 1 shows a schematic representation of a plate of the valve arrangement with an associated vane set.

[0074] FIG. 2 shows a schematic representation of two plates of the valve arrangement with an associated vane set.

[0075] FIG. 3 shows a three-dimensional schematic representation of two plates of the valve arrangement with an associated vane set.

[0076] FIG. 4A shows a three-dimensional schematic representation of multiple plates of the valve arrangement with associated vane sets.

[0077] FIG. 4B shows a two-dimensional schematic representation of a side view of multiple plates of the valve arrangement with vane sets omitted to aid intelligibility.

[0078] FIGS. 5A, 5B 5C, 5D, 5E and 5F are schematic representations of operational steps of a liquid ring system.

[0079] FIG. 6A shows a three-dimensional schematic representation of two plates of the valve arrangement with an associated vane set and tubular members attached to a subset of the valves.

[0080] FIG. 6B shows a schematic representation of a chamber net of the valve arrangement described herein.

[0081] FIGS. 6C and 6D show schematic representations of a chamber net of the valve arrangement described herein with additional tubular members

[0082] FIG. 7 shows a flowchart in accordance with a method for operating a liquid ring system.

[0083] FIG. 8 shows a flowchart in accordance with a method for operating a valve arrangement in a liquid ring system.

DETAILED DESCRIPTION

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced 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.

[0093] 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.

[0094] 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.

[0095] The use of the term “expand” may mean “decompress” or “increase in volume” in certain circumstances. Similarly, the use of the term “expandable” may mean “decompressible” or “increasable in volume” in certain circumstances.

[0096] The term “impeller” is defined herein as a rotating part designed to move fluid by rotation.

[0097] 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.

[0098] FIG. 1 shows a schematic representation of a plate 102 of the valve arrangement 100 with an associated vane set. The schematic representation shows an end view including the face of the plate 102. The vane set is shown with vanes 108, 109. This schematic representation shows a series of set of eight vanes extending radially towards a common point. The common point may be the center of the plate 112, as shown in FIG. 1. However, the vanes of the vane set may extend toward a common point anywhere on the face of the plate 102, and/or may extend towards a common and/or central shape. For example, the vanes, 108 109 may extend towards a common shape that is not in the center, or towards a common shape in the center without being directed toward the center of the plate 112. In some examples, as shown in FIG. 1, the vanes extend towards a common central point at center of the plate 112, but also extend toward a common central shape 114. The common or central shape may be any known geometric shape such as a circle, ellipse, square, rectangle, pentagon or hexagon. The common and/or central shape may be defined by a bar or axle to which the plate is attached or configured to be attached. Each vane 108, 109 of the vane set has at least two faces. A vane 109 of the vane set has a first face 110A and a second face. A vane 108 of the vane set has a first face and a second face 110B. The vanes 108, 109 may extend away from the plate 102. For example, the vanes 108, 109 may extend away from the plate, perpendicular to the plate 102. The first face of each vane may face in one rotational direction. The second face of each vane may face in a different rotational direction to the first face.

[0099] The plate 102 comprises valves 104A-H. The schematic shows the valves by way of example as circular, but the valves could alternatively be any other geometric profile such as a square, rectangle or ellipse. The valves 104A-H permit fluid to pass through an opening 106. This opening 106 may be a hole or cut out. Alternatively, the opening may comprise a flow control valve such as a backflow valve and/or pressure sensitive valve. The plate may be configured to be rotated. The plate 102 may be configured to rotate about an axis perpendicular to the plate center 112.

[0100] FIG. 2 shows a schematic representation of a first plate 102 and a second plate 202 of the valve arrangement 200 with an associated vane set. The first plate 102 is represented by a solid line. The second plate 202 is represented by a dashed line. The schematic representation shows an end view of the two plates 102, 202, wherein the two plates are facing each other. That is, in some examples and as shown in FIG. 2, the second plate 202 is disposed behind the first plate 102. The first plate 102 and second plate 202 may form a plurality of plates. Features described in relation to FIG. 1 may also apply to the corresponding features shown in FIG. 2.

[0101] The vane set is shown with vanes 108, 109. The vanes 108, 109 of the vane set extend from first plate 102 to the second plate 202. The vanes 108, 109 are disposed between the first plate 102 and the second plate 202. This schematic representation shows a series of set of eight vanes extending radially towards a common point. The common point may be the center of the first plate 102 or the second plate 202. The center of each plate of the plurality of plates 102, 202 may be aligned to one another. The vanes of the vane set may extend toward a common point anywhere on the face of the first plate 102 or second plate 202, and/or may extend towards a common or central shape. The common or central shape may be any known geometric shape such as a circle, ellipse, square, rectangle, pentagon or hexagon. The common or central shape may be defined by a bar or axle to which the plate is attached or configured to be attached. Alternatively or additionally, the common or central shape may be defined by a bar or axle to which the plate or vane set is attached or configured to be attached. Each vane 108, 109 of the vane set has at least two faces. A vane 109 of the vane set has a first face 110A and a second face. A vane 108 of the vane set has a first face and a second face 110B. The vanes 108, 109 may extend from the first plate 102 to the second plate 202. For example, the vanes 108, 109 may extend away from the first plate 102 and towards the second plate 202. For example, the vanes 108, 109 may extend between the first plate 102 and second plate 202, perpendicularly to the first plate 102 or the second plate 202.

[0102] The first plate 102 comprises valves 104A-H. The second plate comprises valves 204A-H, wherein the valves 204A-H of the second plate 202 are shown with a dashed line. A first chamber may be formed between two adjacent vanes 108, 109, the first plate 102 and the second plate 202. Alternatively or additionally, the first chamber may be formed between the first plate 102, the second plate 202 and two vanes 108, 109 that face each other. Alternatively or additionally, the first chamber may be formed between the first plate 102, the second plate 202 and a first face of a first vane 110A and a second face of a second vane 110B. In some examples, the two vane faces may be different faces of the same vane, for example, if the vane set includes only one vane.

[0103] The schematic shows the valves 104A-H, 204A-H by way of example as circular, but the valves 104A-H, 204A-H could alternatively be any other geometric profile such as a square, rectangle or ellipse. The valves 104A-H, 204A-H permit fluid to pass through an opening 106, 206. This opening 106, 206 may be a hole or cut out. Alternatively, the opening 106, 206 may comprise a flow control valve, such as a backflow valve and/or pressure sensitive valve. Each plate may be suitable for rotation or configured to be rotated. That is, the plate may comprise a central fixing for connection to a bar or axle. Alternatively or additionally, each plate may comprise a perimetral member for imparting the force from a rotational member, such as a motor, to the plate. The perimetral member may be a toothed wheel, magnet or wire. Each plate 102, 202 may be configured to rotate about an axis perpendicular to the center of the respective plate.

[0104] FIG. 3 shows a three-dimensional schematic representation 300 of two plates 302A, 302B of the valve arrangement 300 with an associated vane set 308, 309. Dashed lines show edges that may not be visible if, for example, the vanes are opaque. Some vanes are not shown between the plates to aid intelligibility.

[0105] The first plate 302A may be joined to the second plate 302B. For example, the first plate 302A may be joined to the second plate 302B by at least one vane of the vane set 308, 309. The first plate 302A and the second plate 302B are opposite one another and facing each other. The first plate 302A may be parallel to the second plate 302B. The first plate 302A and the second plate 302B may form a plurality of plates. Features described in relation to FIGS. 1 and/or 2 may also apply to the corresponding features shown in FIG. 3.

[0106] The vane set is shown with vanes 308, 309. The vanes 308, 309 of the vane set extend from first plate 302A to the second plate 302B. A common point of each plate of the plurality of plates is aligned to one another. In some examples, as shown in FIG. 3, the common point is the center 312 of each plate. The common point of each plate may be aligned to an axis 313. The plurality of plates 302A, 302B may be configured to rotate about the axis 313.

[0107] The vanes of the vane set may extend toward a common point anywhere on the face of the first plate 302A or second plate 302B, and/or may extend towards a common or central shape. In some examples, as shown in FIG. 3, the vanes extend toward an axis 313 about which the plurality of plates 302A, 302B is configured to rotate.

[0108] The first plate 302A comprises valves 304A. The second plate comprises valves 304B. A first chamber may be formed between two adjacent vanes 308, 309, the first plate 302A and the second plate 302B. It may be understood that corresponding chambers can be formed by additional vanes, in the example shown in FIG. 3 there are four chambers. Each chamber may be formed between two adjacent vanes 308, 309 of the vane set, the first plate 302A and the second plate 302B.

[0109] Each chamber may be hollow. Each chamber may partially contain a volume in the shape of a cylindrical sector, as shown in FIG. 3, or any other three-dimensional geometric shape such as a cuboid or cone. It may be understood that the volume of a cylindrical sector may be defined by an inner radius, an outer radius, a height, and angle. The volume partially contained by each chamber may be contained, except for valves, on all but one side and/or all but one surface of the volume. In this way, the chamber may be configured to be sealed by a sealing fluid.

[0110] The valve arrangement 300 may be rotated at a first speed about the axis 313. The axis 313 may extend from the face of the first plate, and/or may extend perpendicularly to a face of the first plate 302A and/or the second plate 302B. The valve arrangement may be configured to allow the second valve 304B to be submerged in a sealing fluid when rotated. The sealing fluid is not part of the valve arrangement 300, as such, and the valve arrangement 300 may be preconfigured based on a predetermined maximum inner diameter of a hollow tube of sealing fluid. The configuration based on a predetermined maximum inner diameter of a hollow tube of sealing fluid also allows the valve arrangement 300 to be configured to, when rotated in use, allow the first valve 304A to emerge from the predetermined maximum inner diameter of the hollow tube of sealing fluid and submerge the first valve 304A through the predetermined maximum inner diameter of the hollow tube of sealing fluid to fully enclose the first chamber within the bounds of the first plate, the second plate, the first face of a first vane of the vane set, the second face of a second vane of the vane set, and a sealing fluid (e.g. a hollow tube of sealing fluid). When fully enclosed, a penetration depth of the first chamber into the predetermined maximum inner diameter of the hollow tube of sealing fluid can be adjusted as part of the rotation of the valve arrangement 300 about the axis 313, based at least in part on a predetermined offset between a center of said predetermined maximum inner diameter and the axis 313. The position of axis 313 may be predetermined in relation to the predetermined maximum inner diameter of the hollow tube. The axis 313 may be parallel to the center of said predetermined maximum inner diameter of the hollow tube and the axis 313, wherein the center of the said predetermined maximum inner diameter may refer to a line extending along the tube at the center of the diameter of the tube. At a stage of the rotation, the second valve 304B may emerge from the predetermined maximum inner diameter of the hollow tube of sealing fluid and be configured to allow working fluid to leave the chamber through a different valve, and at a different pressure, to which it entered.

[0111] FIG. 4A shows a three-dimensional schematic representation of multiple plates 402A-D of the valve arrangement 400 with associated vane sets. 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. Features described in relation to FIGS. 1, 2 and/or 3 may also apply to the corresponding features shown in FIG. 4A.

[0112] The first plate 402A may be joined to the second plate 402B, the third plate 402C and the fourth plate 402D. Each plate 402A-D may retain an orientation that is fixed relative to each other plate in the plurality of plates 402A-D. The first plate 402A and the second plate 402B may form a pair of plates. The second plate 402B and the third plate 402C may form a pair of plates. The third plate 402C and the fourth plate 402D 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 disposed therebetween. The associated vane set being a vane set as described herein, for example, in relation to FIGS. 1, 2 and/or 3. Each pair of plates and the associated vane set therebetween may form a stage 421, 422, 423 or, more specifically, a first stage 421, a second stage 422 and a third stage 423. The first stage may be configured to be closest to a working fluid inlet and each progressive stage may be arranged to get progressively closer to a working fluid outlet. A first vane set may be disposed between the first plate 402A and the second plate 402B, a second vane set may be disposed between the second plate 402B and the third plate 402C, and a third vane set may be disposed between the third plate 402C and the fourth plate 402D.

[0113] Each vane set of the valve arrangement 400 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 valve arrangement 400 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 from the adjacent vane sets to provide a path for the working fluid that is helical relative to the valve arrangement. This helical path maximizes the path length of the working fluid through the system and, in this way, increases the change in volume of the working fluid provided by a valve arrangement of a given size.

[0114] A first chamber may be formed between two adjacent vanes 408A, 409A, the first plate 402A and the second plate 402B. A second chamber may be formed between two adjacent vanes 408B, 409B, the second plate 402B and the third plate 402C. aforementioned first and second chambers are successive chambers, because a valve 404B 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 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 chamber will further decrease the pressure of the working fluid output from the first chamber.

[0115] The valves of each successive plate of the valve arrangement 400 may not overlap. Valves that overlap are, for example, valves which are arranged to enter and/or exit the sealing fluid (or a predetermined maximum inner diameter of a hollow tube representing sealing fluid) at the same time. For example, the valve 404A of the first plate 402A may not overlap the valve 404B of the second plate 402B and valve 404B of the second plate 402B may not overlap with the valve 404C of the third plate 402C. However, valves of non-successive plates may overlap, for example the valves 404A, 404C of the first and third plates 402A, 402C may overlap. In some examples, the valve position may alternate between plates. For example, the valve(s) 404A of the first plate 402A may overlap the valve(s) 404C of the third plate 402C and valve(s) 404B of the second plate 402B may overlap the valve(s) 404D of the fourth plate 402D.

[0116] The valve arrangement 400 may be rotated at a first speed about the axis 413 as described in relation to FIG. 3. Furthermore, at a stage of the rotation, the second valve 404B may emerge from the predetermined maximum inner diameter of the hollow tube of sealing fluid and be configured to allow working fluid to leave the first chamber enter the second chamber through said second valve 404B, wherein the first chamber and second chamber are successive chambers. Successive chambers may be configured to operate at alternate compression stages. For example, the valve arrangement 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 valve arrangement 400 as the third chamber.

[0117] The valve arrangement may be configured to ensure that, in use, the sealing fluid does not migrate along the valve arrangement with the working fluid. The valve arrangement may be configured to ensure that, in use, there is insignificant force, or no overall force, exerted by said valve arrangement on the sealing fluid in a direction perpendicular to the plates of the valve arrangement.

[0118] As described above, an effective chamber may encompass different sub-chambers depending on the rotational stage of the valve arrangement. For example, the effective chamber may encompass a chamber of stages 421 and 422 in one rotational stage and encompass a chamber of stages 422 and 423 in a second rotational stage. Rotational stages of the valve arrangement refer to rotational positions of the valve arrangement when it is rotated about the axis 413, about which the valve arrangement is configured to be rotated.

[0119] FIG. 4B shows a two-dimensional schematic representation of a side view of multiple plates 430-446 of the valve arrangement with the vane sets omitted to aid intelligibility. In this example, a rotational device 428, such as a motor, is configured to impart a rotational force to the rod 426. The plates 430-446 are directly attached to the rod. In this way, the plates may be configured to rotate at the same speed as the rod 426. In some examples, the spacing 448, 450, 452 between the plates may be equal, such that the distances denoted by 448, 450 and 452 are the same. In this example, the second distance 450 between the second 432 and third 434 plates is smaller than the first distance 448 between the first 430 and second 432 plates. In some examples, the second distance 450 between the second 432 and third 434 plates may be larger than the first distance 448 between the first 430 and second 432 plates.

[0120] FIGS. 5A, 5B 5C, 5D, 5E and 5F are schematic representations of operational steps of a liquid ring system. The operational steps are ordered, by way of example only, to form a liquid ring compressor. In some examples, the steps may be performed in the order listed, that is 5A, 5B, 5C, 5D, 5E, then 5F. FIGS. 5A-F show an end view of a tubular vessel 502 containing sealing fluid 504. It may be understood that the tubular vessel is enclosed at each end, but this enclosure at each end is not shown. The predetermined maximum inner diameter of a hollow tube of sealing fluid may be the diameter of the circle 505. The circle 505 may extend throughout the tubular vessel 502. The area 528 within the circle 505 may be devoid of sealing fluid. The sealing fluid 504 may form a hollow tubular shape, such as the hollow cylindrical shape show in in FIGS. 5A-F, based on a centrifugal force imparted to the sealing fluid 504 by the rotation of the tubular vessel 502 and/or the agitation from the vanes 512, 516 of the valve arrangement 524.

[0121] The valve arrangement 524 may be, or be configured to be, rotated in a first direction 535 at a first speed. For example, the valve arrangement 524 may be rotated about a common point 514. The tubular vessel 502 may be, or be configured to be, rotated in a second direction 534 at a second speed. For example, the tubular vessel 502 may be rotated about a common and/or central point 506, shown only FIG. 5A to aid intelligibility. The common and/or central points 506, 514 of the tubular vessel 502 and valve arrangement 524 may be spaced apart by an offset 532.

[0122] The valve arrangement 524 may be, for example, a valve arrangement as described in any one of FIG. 2, 3, or 4. The valves 510, 519, 520, 526 shown with a solid line are disposed on a first plate. The valves 508, 518, 522, 530 shown with a dashed line in FIG. 5F are disposed on a second plate, wherein in the second plate is disposed behind the first plate with a vane set therebetween. The vane set shown in FIGS. 5A-F has four vanes and four chambers are formed therebetween. Each chamber is shown with two associated valves in FIG. 5F, but each chamber may have, or be associated with, more than two valves or at least two valves.

[0123] FIG. 5A shows first rotational stage 500A of the valve arrangement 524. The area 528 in front of the first plate contains a working fluid at a first pressure, which is allowed to enter the first chamber at the first pressure through the first valve 526. The working fluid being provided to the tubular vessel 502 from a working fluid inlet valve (not shown) disposed on the tubular vessel 502. The working fluid flows in through the first valve 526 to fill the associated chamber with working fluid 536 (horizontal lines) at the first pressure.

[0124] FIG. 5B shows a second rotational stage 500B of the valve arrangement 524. This rotational stage may follow the first rotational stage when rotating the valve arrangement 524 in the first direction 535. In this stage, the volume of the chamber associated with valve 526 has increased because there is less sealing fluid present within this chamber. As the valve 526 remains exposed to the working fluid at the first pressure, the chamber will fill to include an increased volume of working fluid 536 at the first pressure.

[0125] FIG. 5C shows a third rotational stage 500C of the valve arrangement 524. This rotational stage may follow at least one of the first and second rotational stages when rotating the valve arrangement 524 in the first direction 535. In this stage, the volume of the chamber associated with valve 526 has increased further because there is less sealing fluid present within this chamber. As the valve 526 remains exposed to the working fluid at the first pressure, the chamber will fill to include an increased volume of working fluid 536 at the first pressure.

[0126] FIG. 5D shows a fourth rotational stage 500D of the valve arrangement 524. This rotational stage may follow at least one of the first, second or third rotational stages when rotating the valve arrangement 524 in the first direction 535. In this stage, the volume of the chamber associated with valve 526 has increased to its maximum point because the chamber is at the stage of rotation in which it contains the least sealing fluid 504. As the valve 526 remains exposed to the working fluid at the first pressure, the chamber will fill to include an increased volume of working fluid 536 at the first pressure.

[0127] FIG. 5E shows a fifth rotational stage 500E of the valve arrangement 524. This rotational stage may follow at least one of the first, second, third or fourth rotational stages when rotating the valve arrangement 524 in the first direction 535. As the rotation of the valve arrangement 524 continues in the first direction 535 the volume of the chamber associated with valve 526 decreases due to an increase in sealing fluid 504 between the vanes 512, 516 associated with the valve 526. The decreased volume of the chamber associated with valve 526 results in a reduced volume of the working fluid. The mass of the working fluid is unchanged because backflow through the valve arrangement 524 is prevented. As the volume of the chamber, and therefore the working fluid contained within the chamber decreases, but the mass of the working fluid is unchanged, the pressure of the working fluid 536 within the chamber is increased.

[0128] FIG. 5F shows the sixth rotational stage 500F of the valve arrangement 524. This rotational stage may follow at least one of the first, second, third, fourth or fifth rotational stages when rotating the valve arrangement 524 in the first direction 535. As the rotation of the valve arrangement 524 continues in the first direction 535 the volume of the chamber associated with valve 526 decreases due to an increase in sealing fluid 504 between the vanes 512, 516 associated with the valve 526. The decreased volume of the chamber associated with valve 526 results in a reduced volume of the working fluid. The mass of the working fluid is unchanged because backflow through the valve arrangement 524 is prevented. As the volume of the chamber, and therefore the working fluid contained within the chamber decreases, but the mass of the working fluid is unchanged, the pressure of the working fluid 536 within the chamber is therefore increased.

[0129] Due to at least one of this increase in pressure and the rotational position of the valve arrangement, this compressed working fluid 536 is allowed to pass through the valve 508, either into the next stage of the liquid ring system or though the outlet of the tubular vessel. In some examples, the volume of working fluid within the chamber would decrease to less than half of its original volume. Decreasing the volume of the working fluid to half of its original volume would result in the pressure of the working fluid doubling. The rotation of the valve arrangement 524 may continue until the stage described in relation to FIG. 5A is again reached.

[0130] Backflow through the valve arrangement during compression may be prevented in a number of ways. In some examples, each valve of the at least one valve arrangement comprises a non-return valve and/or a pressure sensitive valve to prevent the working fluid from escaping back through valve 526. In other examples, the valve 526 may be arranged to be submerged in, or otherwise sealed by, the sealing fluid 504 to prevent the flow of working fluid therethrough as the working fluid is compressed. The valve 508 may include a pressure sensitive valve, to prevent working fluid from passing through the valve 508 before the working fluid 536 is compressed to a predefined minimum threshold pressure. In some examples, the valve 508 may be arranged to be submerged in the sealing fluid 504, or otherwise prevented from flowing into another volume and/or chamber by the sealing fluid 504.

[0131] In some examples, backflow from the chamber can be prevented without necessitating specific pressure sensitive or non-return valves. The valves 526 and 508 of the valve arrangement 524 may be arranged such that: in a first stage of the rotation, valve 526 is unobstructed by sealing fluid 504 to enable working fluid to enter therethrough whilst valve 508 is arranged to be submerged in, or otherwise sealed by, the sealing fluid 504 to prevent the flow of working fluid therethrough, this is maintained as the chamber fills with additional working fluid in stage two; in a third rotational stage, once the chamber is filled with a predetermined volume of working fluid 536, the valves 526 and 508 are both submerged in, or otherwise sealed by, the sealing fluid 504 to prevent the flow of working fluid therethrough, this is maintained in the fourth and fifth rotational stages as the chamber reduces in size and the working fluid is compressed; in a sixth rotational stage, valve 526 is submerged in, or otherwise sealed by, sealing fluid 504 to prevent backflow of the compressed working fluid whilst valve 508 is unobstructed by sealing fluid 504 to enable compressed working fluid to exit therethrough.

[0132] In some examples, backflow through the valve arrangement 524 can be prevented without necessitating specific pressure sensitive or non-return valves, or constraining the compression of a single chamber with specific requirements to prevent backflow. This may enable liquid ring system designs to be provided that are low cost and simple to manufacture, with greater efficiency due to less restrictive design requirements.

[0133] Backflow from a specific chamber can be prevented without necessitating specific pressure sensitive or non-return valves, as described above. A similar approach to prevent backflow can be provided with a group of multiple successive chambers, rather than a single chamber, to prevent backflow. For example, two, three or five successive chambers from two, three or five successive stages of the valve arrangement 524 may be used to prevent backflow in a valve arrangement with four, six or ten stages, respectively. In this way, an angular offset required between the first and second valves to ensure the first and last valve can be simultaneously submerged in the sealing fluid to prevent backflow can be shared between the group of successive chambers, rather than one large angular offset in a single chamber. Angular offset herein defines an angle between the respective centers of two rotationally spaced features, wherein the angle is measured at the point about which the features rotate.

[0134] This group of successive chambers may include valves arranged such that working fluid is permitted to enter all of the chambers in the successive group of chambers at once, with the a valve associated with the last chamber in the successive group of chambers being submerged in, or otherwise sealed by the sealing fluid. Once the successive group of chambers is filled with working fluid, a valve associated with the first chamber of the group of chambers is submerged in, or otherwise sealed, by the sealing fluid 504. The working fluid is then compressed within the successive group of chambers, with the first chamber in the successive group of chambers having reduced in volume by the greatest proportion. The valve associated with the last chamber in the successive group of chambers reaches a stage of the rotation in which it becomes unobstructed as the valve associated with the first chamber in the successive group of chambers becomes submerged in or otherwise sealed by the sealing fluid. This allows the working fluid to move along the valve arrangement, in a successive group of chambers, stage by stage and/or chamber by chamber.

[0135] For example, in a six stage valve arrangement, the successive group of chambers may be three chambers, with working fluid starting in chambers 1, 2 and 3, from stages 1, 2 and 3. Then, after a full rotational cycle has been completed, the working fluid is pushed out from chamber 1 from stage 1 and is instead contained within chambers 2, 3 and 4, from stages 2, 3 and 4. Then, after another rotational cycle is completed, the working fluid is contained within chambers 3, 4 and 5 of stages 3, 4 and 5. In this way, the working fluid in the successive group of chambers takes a helical path about the valve arrangement, relative to the valve arrangement.

[0136] It may be understood that the rotational stages described in FIGS. 5A-F may occur in each chamber of the valve arrangement sequentially as each respective valve emerges from the sealing fluid 504. Similarly, the rotational stages could be reversed, or operated in the reverse direction, to provide a liquid ring expander, rather than the liquid ring compressor described in FIGS. 5A-F by way of example. The representations shown are by way of example only, and it may be understood that the relative sizes may be significantly different from those shown, for example, the plates may be considerably larger than the valves. That is, the diameter of each plate of the plurality of plates may be at least 10, 100 or 1000 times the diameter of each valve of the respective plate.

[0137] The valve arrangement described herein may be modified in various ways to alter characteristics of the compression or decompression cycles. FIG. 6A shows a three-dimensional schematic representation 600 of two plates of the valve arrangement and an associated vane set, as described in relation to FIG. 3. However, the representation 600 further comprises two tubular members 602A, 602B. These tubular members may be implemented on any of the plates described or shown herein to alter the characteristics of the compression or decompression cycles. These tubular members 602A, 602B may be open-ended tubular member members 602A, 602B. Each tubular member having a first end 606A, 606B fluidically connected to a chamber and/or a valve of the chamber. The tubular members have a second end 604A, 604B. The second end of the tubular member may be rotationally offset from the respective valve of the chamber. In some examples, the second end is configured to submerge and emerge from the sealing fluid, and/or a predetermined maximum inner diameter of a hollow tube of sealing fluid, at a different point in the rotation of the valve arrangement to the respective valve of the respective chamber. The tubular members may be attached to a subset of the valves of a plate, a subset of valves of the valve arrangement, all of the valves of a plate, or all of the valves of the valve arrangement. For example, the tubular members may be attached to a subset, or all, of the valves of the first, second, third, fourth and/or last plate of the valve arrangement.

[0138] In this way, the compression or decompression ratio can be configured and optimized for a given application. Furthermore, dimensional flexibility and versatility of the valve arrangement is increased. FIG. 6A shows tubular members connected to only one chamber, but the tubular members may be attached to one or more chambers of the valve arrangement.

[0139] FIG. 6B shows a schematic representation of a chamber net of the valve arrangement. A chamber net as described herein refers to a schematic view of a three-dimensional chamber layout of a valve arrangement represented in two-dimensional space to show the flow of working fluid through the valve arrangement.

[0140] The chamber net shown in FIG. 6B shows a perimeter of a first 612A, second 612B, third 612C and fourth 612D plate of the valve arrangement and the outer most edge of the vanes 614, 615. The plates and vanes of FIG. 6B combine to form the first 610A, second 610B and third 610C stages of the valve arrangement. The valves 619A, 619B are shown by breaks in the plate and the flow 616 of working fluid is shown by dashed arrows.

[0141] A maximum angular offset 618 possible between the chambers in each successive stage in FIG. 6B (i.e. without the tubular members 602A, 602B) may be less than an angular offset between the first 614 and second 615 vanes of a given chamber. More specifically, the maximum angular offset 618 possible between the chambers in each successive stage in FIG. 6B may be the angular offset between the first 614 and second 615 vanes of a given chamber, minus the sum of the maximum angular offset between any two points of the first valve 619A and maximum angular offset between any two points of the second valve 619B.

[0142] FIGS. 6C and 6D show schematic representations of a chamber net of the valve arrangement with tubular members of different configurations.

[0143] The chamber net shown in FIG. 6C shows a perimeter of a first 622A, second 622B, third 622C and fourth 622D plate of the valve arrangement and the outer most edge of the vanes 624. The plates and vanes of FIG. 6C combine to form the first 620A, second 620B and third 620C stages of the valve arrangement. The valves are fluidically connected to tubular members 629. The flow 626 of working fluid through these tubular members 629 is shown by dashed arrows.

[0144] A maximum angular offset 628 possible between the chambers in each successive stage in FIG. 6C is increased by the tubular members 629. The maximum angular offset 628 may be the angular offset between the vanes 624 of a given chamber as shown in FIG. 6C.

[0145] The chamber net shown in FIG. 6D shows a perimeter of a first 632A, second 632B, and third 632C plate of the valve arrangement and the outer most edge of the vanes 634. The plates and vanes of FIG. 6D combine to form the first 630A, and second 630B stages of the valve arrangement. The valves are fluidically connected to tubular members 639. The flow 636 of working fluid through these tubular members 639 is shown by dashed arrows.

[0146] A maximum angular offset 638 possible between the chambers in each successive stage in FIG. 6D is increased by the tubular members 639. The maximum angular offset 638 may be greater than the angular offset between the vanes 624 of a given chamber as shown in FIG. 6D.

[0147] FIG. 7 shows a flowchart in accordance with a method for operating a liquid ring system. The method comprises rotating 702 the tubular vessel of the liquid ring system about the second axis at a second speed and applying 704 working fluid, from a source of working fluid, at a first pressure to the working fluid inlet. The method also comprises rotating 706 the valve arrangement about the first axis at the first speed to cause a change in pressure within the first chamber by submerging 708 the second valve into the sealing fluid, emerging 710 the first valve from the sealing fluid, submerging 712 the first valve into the sealing fluid, adjusting 714 a penetration depth of a first chamber into the sealing fluid, and emerging 716 the second valve from the sealing fluid.

[0148] FIG. 8 shows a flowchart in accordance with a method for operating a valve arrangement in a liquid ring system. The method comprising rotating 802 the valve arrangement described herein about the first axis at the first speed to cause a change in pressure within the first chamber by: submerging 804 the second valve through a predetermined maximum inner diameter of a hollow tube of sealing fluid, emerging 806 the first valve from the predetermined maximum inner diameter of the hollow tube of sealing fluid, submerging 808 the first valve through the predetermined maximum inner diameter of the hollow tube of sealing fluid, adjusting 810 a penetration depth of the first chamber into the predetermined maximum inner diameter of the hollow tube of sealing fluid, and emerging 812 the second valve from the predetermined maximum inner diameter of the hollow tube of sealing fluid.