Pressure exchange chamber

Abstract

A pressure exchange chamber, the pressure exchange chamber comprising: a pressure exchange chamber tube (12), the pressure exchange chamber tube extending around a periphery; a drive fluid input valve (44) and a drive fluid output valve (46), both valves being enclosed by the pressure exchange chamber tubes; and a slurry input valve (34) and a slurry output valve (36), both valves being enclosed by the pressure exchange chamber tubes. Also disclosed is a hydraulic ore lifting system (HOHS) for the ocean comprising a plurality of such pressure exchange chambers.

Description

Technical Field

[0001] The present invention relates to a pressure exchange chamber. In particular, although not exclusively, the present invention relates to a pressure exchange chamber for use in the mining and mineral processing industries, in particular for use in a hydraulic ore hoisting system (HOHS) located on or near the sea or lake bed. Background Art

[0002] In the mineral processing industry, one problem involves transporting ore from an underground or subsea location to a surface level. A novel system for such transport is described in PCT Application No. PCT / IB2019 / 055957 in the name of Weir Minerals Netherlands BV and is referred to as a HOHS. Other types of HOHS are also available.

[0003] The HOHS described in PCT / IB2019 / 055957 requires a pressure exchange chamber system as illustrated in FIG1 . The pressure exchange chamber system 1 includes a plurality of pressure exchange chambers 2, 3, 4 extending a considerable distance, such as tens of meters, between the driving fluid (or water) input end 5 and the slurry output end 6. Each pressure exchange chamber includes a set of water valves 7 at the driving fluid input end 5 and a set of slurry valves 8 at the slurry output end 6. The pressure exchange chambers 2, 3, 4 are illustrated in FIG1 in a linear arrangement. However, when deployed in a deep sea environment, the pressure exchange chamber system 1 (and therefore the pressure exchange chambers 2, 3, 4) is expected to be lowered through a moon pool (an opening on the hull of the ship) and lifted back from the seabed through the moon pool. The size of the moon pool determines the maximum size of the pressure exchange chamber system 1. Therefore, it is difficult to design a pressure exchange system that can be deployed through a moon pool but still has a sufficiently long chamber length (usually more than 60m long, sometimes more than 100m or 150m long) to enable the HOHS to work effectively.

[0004] Furthermore, for flow assurance and system reliability in the HOHS, the pressure exchange chamber is ideally a linear pump chamber arranged in a horizontal plane with no height difference between the water input and the slurry output. A pressure exchange chamber with multiple bends increases the fragmentation of polymetallic nodules transported in the slurry. Any gradient or height difference along the pressure exchange chamber increases the risk of blockage in the chamber.

[0005] One of the objects of embodiments of the present invention is to obviate or mitigate the above-mentioned disadvantages or other disadvantages of the prior art, or to provide a useful alternative to the prior art or improved operation thereof.

[0006] Unless otherwise stated, the various aspects described in detail below are independent of each other; however, unless technically infeasible, the features of one aspect can be combined with any other aspect to create a new aspect. Any claim corresponding to one aspect should not be interpreted as including any elements or features of other aspects unless explicitly stated in the claim.

[0007] Reference in this specification to any prior publication (or information derived from an prior publication) or any known matter is not, and should not be taken as, an acknowledgment or acceptance or any form of implication that the prior publication (or information derived from an prior publication) or known matter forms part of the common general knowledge in the field to which this specification relates. Summary of the invention

[0008] This Summary is provided to introduce some concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0009] According to a first aspect, a pressure exchange chamber is provided, comprising (i) a pressure exchange chamber tube, which extends around a periphery; (ii) a drive fluid input valve and a drive fluid output valve, both valves being enclosed by the pressure exchange chamber tube; and (iii) a slurry input valve and a slurry output valve, both valves being enclosed by the pressure exchange chamber tube.

[0010] The pressure exchange chamber tube may extend completely around the perimeter so that it completely encloses the drive fluid valve and the slurry valve; alternatively, the pressure exchange chamber tube may extend around a majority of the perimeter so that it substantially encloses those valves (leaving only relatively small gaps).

[0011] The actuating fluid valve and the slurry valve may be located generally centrally within the pressure exchange chamber tube. The slurry input valve may be centrally located, and the actuating fluid valve may be located on opposite sides of the slurry input valve.

[0012] The slurry valve may be positioned between the first set of actuation fluid valves and the second set of actuation fluid valves.

[0013] The pressure exchange chamber tubes may be substantially evenly disposed about the actuating fluid valve and / or slurry valve; thereby providing a substantially centered center of gravity for the pressure exchange system. The substantially centered center of gravity facilitates deployment of the pressure exchange chamber from a moon pool of a surface vessel or from another type of floating system. By having a substantially centered center of gravity, a hook attachment coupled to a riser extending from the pressure exchange chamber minimizes tilting of the pressure exchange chamber during operation and deployment. This ensures that the pressure exchange chamber is in a balanced operating state.

[0014] The pressure exchange chamber may also include a drive fluid riser connection and a slurry input pipe, both pipes being enclosed by the pressure exchange chamber pipe.

[0015] The pressure exchange chamber may further include a drive fluid output pipe and a slurry output pipe, both pipes being enclosed by the pressure exchange chamber pipe and optionally coupled to a portion of the valve.

[0016] According to a second aspect of the present invention, a pressure exchange chamber system is provided, comprising: a central frame; and a plurality of pressure exchange chambers according to the first aspect, wherein the pressure exchange chamber tubes are arranged in a stacking plane around the central frame, and each of a plurality of groups of drive fluid input valves and drive fluid output valves and slurry input valves and output valves is associated with a corresponding pressure exchange chamber tube; and the plurality of groups of drive fluid valves and slurry valves are supported by the central frame.

[0017] The pressure exchange chamber tubes are preferably arranged in a substantially horizontal plane and stacked vertically aligned with each other. By arranging the tubes in a substantially horizontal plane, the bends in the tubes are in a horizontal plane and preferably have the same diameter, which will reduce the risk of blockage.

[0018] The pressure exchange chamber system optionally includes a drive fluid input pipe and a slurry input pipe. The drive fluid input pipe may include or be connected to a marine pipe (or riser) extending from the sea surface to the pressure exchange chamber system. The slurry input pipe may be connected to a slurry feed pump.

[0019] The pressure exchange chamber system optionally includes a drive fluid output pipe and a slurry output pipe. The slurry output pipe may include or be connected to a marine riser extending from the pressure exchange chamber system to the sea surface.

[0020] The drive fluid input and output pipes and the slurry input and output pipes can be located within the central frame, near the center of gravity of the pressure exchange chamber system; thereby facilitating the deployment of the pressure exchange chamber system through a moon pool of a surface vessel (such as a ship). The pressure exchange chamber system also facilitates the recovery of the system through a moon pool of the same size.

[0021] Each actuation fluid input valve and actuation fluid output valve (of the same PEC) may have an associated compression valve and pressure relief valve, and these compression valves and pressure relief valves may be positioned in line with the associated actuation fluid input valve and actuation fluid output valve and at approximately the same height as the associated actuation fluid input valve and actuation fluid output valve.

[0022] Each actuation fluid input valve and actuation fluid output valve (of the same PEC) may be located at a similar vertical position (height) as the corresponding slurry output valve, and may be located at a similar vertical position (height) as the corresponding slurry input valve. Alternatively, each actuation fluid input valve and actuation fluid output valve (of the same PEC) may be vertically offset from the corresponding slurry output valve and the corresponding slurry input valve.

[0023] One set of actuation fluid valves (for one PEC) may be located at a similar vertical position as another set of actuation fluid valves (for another PEC).

[0024] One set of actuation fluid valves (for one PEC) may be vertically offset from another set of actuation fluid valves (for another PEC). Similarly, one set of slurry valves may be vertically offset from another set of slurry valves.

[0025] The pressure exchange chamber system optionally includes a drive fluid input manifold, a drive fluid output manifold, a slurry input manifold, and a slurry output manifold.

[0026] The drive fluid input manifold may include a vertically extending pipe and a plurality of pipe segments extending downwardly from the vertically extending pipe, each downwardly extending pipe segment being coupled to a respective drive fluid input valve at a lower end.

[0027] The slurry input valve may be centrally located and the actuation fluid valves may be located on opposite sides of the slurry input valve, thereby minimizing the length of the common slurry input manifold.

[0028] The drive fluid output manifold may include a vertically extending pipe and a plurality of pipe segments extending upwardly from the vertically extending pipe, each upwardly extending pipe segment being coupled to a respective drive fluid output valve at an upper end.

[0029] The slurry input manifold may include a vertically extending pipe and a plurality of pipe segments extending upwardly from the vertically extending pipe, each upwardly extending pipe segment being coupled to a respective slurry input valve at an upper end. By arranging the pipe segments in an upward direction toward the slurry input valve, when the slurry input flow stops, any slurry in the pipe segments flows downwardly (due to gravity) and away from the slurry input valve. This reduces the risk of clogging the slurry input valve.

[0030] The slurry output manifold may include a vertically extending pipe and a plurality of pipe segments extending downwardly from the vertically extending pipe, each downwardly extending pipe segment being coupled to a respective slurry output valve at a lower end.

[0031] Each pressure exchange chamber tube may define a generally rectangular (in some embodiments, generally square) shape having bends at the corners to reduce particle size fragmentation, tube wear, and plugging.

[0032] Each pressure exchange chamber tube may include a thermoplastic composite tube (TCP). Optionally, each pressure exchange chamber tube may include a metal (such as steel) tube. The advantages of TCP include less weight than steel, corrosion resistance, and improved flexibility for making bends in the TCP compared to metal.

[0033] Optionally, each TCP comprises a circular cross-section.

[0034] Each pressure exchange chamber tube may be coated with a wear-resistant coating on an inner surface.

[0035] Each pressure exchange chamber tube may be relatively long, for example, 40m, 50m, 60m, 70m, 80m, 90m or 100m, 125m or 160m in length.

[0036] The external dimensions of the pressure exchange chamber system may have a footprint of approximately 10 m x 20 m (length x width).

[0037] The pressure exchange chamber system may also include one or more hydraulic power units and slurry feed pumps (one or both of which may be provided in multiples for redundancy purposes), a control cabinet, a pressure relief system, a flow sensor, a buoyancy device, a thrust positioning device for moving the pressure exchange chamber system, etc. The power unit and the pump may be marine-graded to enable operation on or near the seabed.

[0038] The central frame may include a peripheral frame surrounding a core of the central frame. The core may be used to mount the valve. The peripheral frame may be disposed primarily in a horizontal plane. The peripheral frame may include a plurality of upright grids spaced about the peripheral frame, each grid defining a plurality of spaces. Each grid space may be used to support one or more pressure exchange chamber tubes. The peripheral frame may be cantilevered from the core.

[0039] According to a third aspect, there is provided a hydraulic ore hoisting system comprising a pressure exchange chamber according to the second aspect.

[0040] It should now be appreciated that a pressure exchange system may be provided that is easily deployed through a moon pool on a surface vessel on a sea or lake, having improved balance and geometry.

[0041] One advantage of a rectangular PEC system is that the profile or shape is substantially the same as the typical shape of a moonpool of a mining vessel. This means that handling and transporting the PEC system onto and around the deck of a mining vessel and into the moonpool can typically be performed using known underwater equipment handling systems (e.g., transporters, guide systems, carriers, etc.).

[0042] According to a fourth aspect, a pressure exchange chamber is provided, comprising: (i) a pressure exchange chamber tube extending in a substantially horizontal plane and defining a housing; (ii) a drive fluid input valve and a drive fluid output valve; and (iii) a slurry input valve and a slurry output valve; the drive fluid valve and the slurry valve being positioned close to each other.

[0043] The actuating fluid valve and the slurry valve may all be located within the pressure exchanger tube housing. Optionally, the actuating fluid valve and the slurry valve may all be located outside the pressure exchanger tube housing.

[0044] According to a fifth aspect of the present invention, a pressure exchange chamber system is provided, comprising: a plurality of pressure exchange chambers according to the fourth aspect, wherein the pressure exchange chamber tubes are arranged in a vertically spaced stacking plane, and each of a plurality of groups of drive fluid input valves and drive fluid output valves and slurry input valves and slurry output valves is associated with a corresponding pressure exchange chamber tube.

[0045] The pressure exchange chamber tubes may be arranged in two or more vertically spaced stacking planes that are horizontally separated from one another.

[0046] The slurry input valve and the slurry output valve may be enclosed by a set of vertically spaced stacked planes; and the actuation fluid input valve and the actuation fluid output valve may be enclosed by another set of vertically spaced stacked planes.

[0047] Alternatively, the slurry input valve and the slurry output valve and the actuation fluid input valve and the actuation fluid output valve may be located between two adjacent vertically spaced stacking planes. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] FIG. 1 is a simplified schematic diagram of a prior art pressure exchange chamber system.

[0049] The above and other aspects will become apparent from the following detailed description, given by way of example only, with reference to the accompanying drawings, in which:

[0050] Figure 2 is a simplified diagrammatic cutaway perspective view of a pressure exchange chamber system installed in a frame with an auxiliary unit according to a first embodiment of the present invention;

[0051] Figure 3 yes Figure 2 A simplified schematic plan view of the parts (driving fluid valve, compression valve, pressure reducing valve and slurry valve) shown in the pressure exchange chamber system;

[0052] Figure 4 yes Figure 3 a simplified schematic plan view of the valves shown, including their interconnections;

[0053] Figure 5 yes Figure 4 A simplified perspective view of a valve;

[0054] Figure 6 is used for Figures 3 to 5 a pictorial perspective view of a slurry input manifold of a slurry valve;

[0055] Figure 7 yes Figure 2 a plan view of a part of a pressure exchange chamber system (a pressure exchange chamber tube in the pressure exchange chamber tubes);

[0056] Figure 8 yes Figure 7 A perspective view of a pressure exchange chamber tube;

[0057] Fig. 9 yes Figure 2 A diagrammatic perspective view of a pressure exchange chamber of a pressure exchange chamber system;

[0058] Fig. 10A yes Figure 5 A schematic perspective view of a valve with a (highest) pressure exchange chamber pipe connected thereto;

[0059] Fig. 10B yes Figure 5 A diagrammatic perspective view of a valve of , wherein another (second highest) pressure exchange chamber pipe is connected;

[0060] Fig. 10C yes Figure 5 A diagrammatic perspective view of a valve of , wherein yet another (second lowest) pressure exchange chamber pipe is connected;

[0061] Fig. 10D yes Figure 5 A diagrammatic perspective view of a valve of , wherein yet another (lowest) pressure exchange chamber pipe is connected;

[0062] Fig.11 is a simplified pictorial perspective view of another embodiment of a pressure exchange chamber;

[0063] Fig.12 is a simplified pictorial perspective view of yet another embodiment of a pressure exchange chamber;

[0064] Fig.13 is a simplified pictorial perspective view of yet another embodiment of a pressure exchange chamber. Specific implementation plan

[0065] First reference Figure 2 , which is a simplified partial cutaway perspective view of a pressure exchange chamber ("PEC") system 10 according to a first embodiment of the present invention. The PEC system 10 includes a plurality of pressure exchange chambers ("PECs") 12a, 12b, 12c, 12d. In this embodiment, four PECs 12a, 12b, 12c, 12d are provided. Typically, only three of these PECs (e.g., 12a, 12b, 12c) are used, with the fourth PEC (e.g., 12d) being retained as a standby in case one of the three PECs (12a, 12b, 12c) fails. This provides redundancy for continued operation, which is very important because it may be difficult to repair the PEC system 10 in situ on the seabed. The PEC is designed for use in a deep sea environment and may be coupled to the lower portion of a riser, umbilical, cable, or the like.

[0066] Each PEC 12a, 12b, 12c, 12d includes a PEC tube 14a, 14b, 14c, 14d extending around the perimeter in a generally rectangular spiral shape (a spiral having substantially straight sides and bends at the ends of the straight sides). In some embodiments, the rectangular spiral shape may include a square spiral shape. The PEC tubes 14a, 14b, 14c, 14d are arranged in vertically spaced stacking planes (each plane is generally horizontal) around a central frame 16. In this embodiment, the central frame 16 includes welded steel beams, but different materials and connectors may be used in other embodiments.

[0067] The central frame 16 includes a cuboid central core 18 having lateral support wings 20 (only one shown) extending therefrom, and frame extensions (also referred to as perimeter frames) 22 cantilevered from the lateral support wings 20. The frame extensions 22 support a plurality of upright grids 24 spaced about the perimeter frame 22, each grid 24 defining an array of spaces. The corresponding spaces in the upright grids 24 are aligned so that PEC tubes (e.g., 14a) can be routed through the aligned spaces in the upright grids 24. Each grid space supports one or more PEC tubes 14; typically, two PEC tubes (e.g., 14a and 14b) are routed through each grid space.

[0068] Each PEC pipe 14 comprises a thermoplastic composite pipe (TCP) and extends approximately 160 m and has a footprint of approximately 30 m x 20 m (length x width) for its outer dimensions.

[0069] The PEC system 10 also includes a hydraulic power unit 26 and a slurry feed pump 28 (for feeding slurry into the PEC tube 14). Both the hydraulic power unit 26 and the feed pump 28 are coupled to the central frame 16 and are designed for operation in a deep seawater environment (i.e., they are marine-processed). In this embodiment, two hydraulic power units 26 and slurry feed pumps 28 are provided in case either fails during use, but these additional units are not illustrated in the drawings.

[0070] Each PEC 12a, 12b, 12c, 12d also includes an associated valve, which will now be referred to. Figures 3 to 6 These valves are described in detail. They are arranged in a stop valve assembly 30, the central portion 32 of which contains the slurry valves (four slurry input valves 34a, 34b, 34c, 34d and four slurry output valves 36a, 36b, 36c, 36d; one for each PEC) located within the cuboid central core 18.

[0071] The shut-off valve device 30 comprises two side parts 40 , 42 . These side parts 40 , 42 are mounted on opposite lateral support wings 20 .

[0072] The first side portion 40 includes: two driving fluid (or water) input valves 44a, 44b; two driving fluid (or water) output valves 46a, 46b; two compression valves 48a, 48b; and two pressure reducing valves 50a, 50b.

[0073] Similarly, the second side portion 42 includes: two driving fluid (or water) input valves 44c, 44d; two driving fluid (or water) output valves 46c, 46d; two compression valves 48c, 48d; and two pressure reducing valves 50c, 50d.

[0074] The valves in the second side portion 42 are generally located at a higher level (ie, above) than the valves in the first side portion 40 (at Figure 5 ), and is arranged in a mirror-image manner to the valve in the first side portion 40.

[0075] The stop valve assembly 30 is used to control the pressure and fluid flow through the PEC tube 14 (ie, initially allowing the slurry feed pump 28 to fill the PEC tube 14 and then allowing the PD pump to discharge slurry from the PEC tube).

[0076] like Figure 4 As best seen, the inputs and outputs of each PEC 12a, 12b, 12c, 12d are arranged in quadrants of the shutoff valve assembly 30. The inputs and outputs of the first PEC 12a are in the upper left quadrant; the inputs and outputs of the second PEC 12b are in the lower left quadrant; the inputs and outputs of the third PEC 12c are in the lower right quadrant; and the inputs and outputs of the fourth PEC 12d are in the upper right quadrant.

[0077] A single slurry output pipe coupling 60 is located in the center portion 32 and extends upward to meet and connect to a riser (not shown) that lifts the slurry pumped from the PEC system 10 to a dewatering system, such as on the deck of a vessel at the surface. Similarly, a single drive fluid riser coupling 62 is located in the center portion 32 and extends upward to meet and connect to a drive fluid riser (not shown) that is connected to a pump (not shown) at the surface. The single drive fluid riser coupling 62 can be connected to a riser-type pipe that extends to the surface.

[0078] The first drive fluid output pipe 64 is provided for the first PEC valve and the second PEC valve (i.e., at the first quadrant and the second quadrant) and extends downwardly from the first PEC valve and the second PEC valve. Similarly, the second drive fluid output pipe 66 is provided for the third PEC valve and the fourth PEC valve (i.e., at the third quadrant and the fourth quadrant) and extends downwardly from the third PEC valve and the fourth PEC valve. These drive fluid output pipes 64, 66 are arranged at Figure 5In other embodiments, they can be combined into a single drive fluid output tube.

[0079] Single slurry input pipe 68 (at Figure 5 ) is located in the central portion 32 and is fed via the slurry input manifold 70 (at Figure 6 4 (best seen in FIG. 1 ) is connected to four slurry input valves 34a, 34b, 34c, 34d. A single slurry input pipe 68 is connected to a slurry feed pump 28 which fills the PEC tube 14 with slurry.

[0080] The slurry input manifold 70 includes a slurry input connection pipe 72 (which is coupled to the slurry input pipe 68) and a plurality of angled pipe segments 74a, 74b, 74c, 74d extending upward and outward therefrom. Each upwardly angled pipe segment 74a, 74b, 74c, 74d is coupled to a respective slurry input valve 34a, 34b, 34c, 34d at its upper end. By arranging the pipe segments 74a, 74b, 74c, 74d in an upward (and outward) direction toward the slurry input valve 34a, 34b, 34c, 34d, when the slurry input flow stops, any slurry in the pipe segment 74 flows downward (due to gravity) and away from the associated slurry input valve 34. This reduces the risk of clogging or damaging the slurry input valves 34a, 34b, 34c, 34d when they are closed.

[0081] The operation (eg, opening and closing) of the various valves in the cut-off valve arrangement 30 is controlled by the subsea hydraulic power unit 26 .

[0082] A pulsation damper 80 is also provided on the single drive fluid input pipe 62 (at Figure 4 and Figure 5 This can be implemented using a common drive fluid manifold feeding the four PECs 12.

[0083] Reference now Figure 7 and Figure 8, which shows two views of one of the PEC tubes 14a. One end of the PEC tube 14a is a slurry end 82 that is coupled to a slurry tube 84a. The slurry tube 84a is coupled to both a slurry input valve 34a (which opens when the PEC tube 14a is filled with slurry) and a slurry output valve 36a (which opens when the slurry is discharged from the PEC tube 14a and reaches the riser upward along the slurry output tube coupling 60). The other end of the PEC tube 14a is an actuation fluid end 86 that is coupled to an actuation fluid tube 88a. The actuation fluid tube 88a is coupled to both an actuation fluid input valve 44a (which opens when the slurry is discharged from the PEC tube 14a and reaches the riser upward along the slurry output tube coupling 60) and an actuation fluid output valve 46a (which opens when the PEC tube 14a is filled with slurry). Arrow 90 indicates the direction in which the slurry flows into the PEC tube 14a; while arrow 92 indicates the direction in which the slurry flows out of the PEC tube 14a and flows toward the slurry output pipe 60. The PEC tube 14a is raised (inclined) at the driving fluid end 86 and then extends in a rectangular spiral in a horizontal plane. By having an inclined section at the driving fluid end 86, the risk of clogging is reduced because it is mainly the driving fluid (which does not contain nodules or large particles) rather than the slurry that passes through this section.

[0084] Fig. 9 The vertical stacking and surrounding the shut-off valve device 30 are shown. Figure 2 14a, 14b, 14c, 14d of the PEC system 10. The PEC tubes 14 are substantially evenly arranged around the stop valve device 30, thereby ensuring that the center of gravity of the PEC system 10 is close to its geometric center. This facilitates deployment of the PEC system 10 through a moon pool of a surface vessel (not shown). This also ensures that the PEC system 10 is maintained in a generally horizontal position (minimizing any tilt) during operation.

[0085] The PEC system 10 includes a plurality (in this embodiment, four) of PECs 12a, 12b, 12c, 12d arranged in stacking planes that are vertically offset from one another. FIG. 10A to FIG. 10D As best seen in the Fig. 9 , but for further clarity, each figure only shows one of the PEC tubes 14a, 14b, 14c, 14d individually.

[0086] Each PEC tube 14a, 14b, 14c, 14d is disposed in a generally horizontal plane. These planes are generally, but not completely, horizontal because each chamber tube 14a, 14b, 14c, 14d is slightly elevated from the corresponding drive fluid end 86a, 86b, 86c, 86d to the level of the corresponding slurry end 82a, 82b, 82c, 82d to provide space for the tube 14 to continue to enclose the stop valve device 30 in a generally rectangular spiral shape (a spiral having substantially straight sides and bends at the ends of the straight sides). In this embodiment, each PEC tube 14a, 14b, 14c, 14d is elevated to the level of the corresponding drive fluid end 86a, 86b, 86c, 86d before the first bend in the PEC tube 14a, 14b, 14c, 14d.

[0087] It should now be appreciated that the PEC system 10 has the following advantages: (i) a center of gravity close to the center of the PEC system 10, (ii) a relatively small footprint while enabling the PEC tubes 14 to be very long, and (iii) a relatively small number of bends in each PEC tube 14.

[0088] It should be understood that other PEC system configurations are possible within the scope of the claims. For example, Fig.11 Another arrangement of a PEC 112 is shown (simplified for clarity by removing the compression and pressure relief valves) in which the shut-off valve arrangement 130 is different, but the PEC tubes 14a, 14b, 14c, 14d are the same or very similar to the tubes of the PEC system 10.

[0089] Fig.12 A third PEC system 212 is shown in which the stop valve arrangement 230 is different and the PEC tubes 214a, 214b, 214c, 214d are also different from the tubes of the PEC system 10. The stop valve arrangement 230 is split, the slurry input valve 234 and the slurry output valve 236 are located within and enclosed by two PEC tubes 214a, 214b as the stop valve 230a; and the actuation fluid input valve 244 and the actuation fluid output valve 246 are located within and enclosed by the other two PEC tubes 214c, 214d as the stop valve 230b. The PEC system 212 has the following advantages: each tube 214a, 214b, 214c, 214d can extend in the same plane without any height changes (i.e., there is no height difference along the PEC tube 214).

[0090] Fig.13 A fourth PEC system 312 is shown in which a stop valve device 330 is centrally located and positioned between two groups of PEC tubes. The first group includes two PEC tubes 314a, 314b; and the second group also includes two PEC tubes 314c, 314d.

[0091] In use, the PEC system 10 is located near the seabed or lakebed (e.g., tens of meters above the seabed or lakebed), which is significantly lower than the final delivery point to which the slurry is to be delivered (e.g., at the sea surface). The PEC system 10 can be freely suspended (via a riser) from a ship (or other vessel) above the sea surface. In this embodiment, the slurry includes ore particles (also known as polymetallic nodules) ranging in size from 10 to 200 mm in a liquid carrier to produce a slurry that entrains and suspends the ore particles.

[0092] In this embodiment, each PEC tube 14 comprises a thermoplastic composite tube (TCP); although in other embodiments, the tubes may be made of different materials or composite materials, and the inner surface of the PEC tube 14 may include a wear-resistant or low-friction coating. Advantages of using TCP for the PEC tubes 14 include lighter weight than steel or another metal, corrosion and wear resistance, and improved flexibility in making bends in the TCP compared to metal.

[0093] In this embodiment, each PEC tube 14 is approximately 160 m long, although different tube lengths may be used in other embodiments.

[0094] It should now be appreciated that prior art hydraulic ore hoisting systems may be upgraded by replacing the PEC system with the PEC system 10 .

[0095] It should now be appreciated that a PEC system can be provided that is easily deployed through a moon pool on a surface vessel on a sea or lake, having improved balance and geometry.

[0096] Another advantage of the PEC system 10 is its compactness and symmetry, which facilitates easy handling and transportation to and around a mining vessel (eg, an ocean-going vessel) and through a moon pool of a vessel.

[0097] Another advantage of the PEC system 10 is that all valves of one PEC pipe (eg, 14 a ) are located in one quadrant of the block valve assembly 30 , which minimizes the overall height of the PEC system 10 .

[0098] The common slurry input manifold enables the height of the PEC 12 to be lowered, which reduces the volume of settled solids from the slurry.

[0099] Another advantage of the vertically in-line stacked PEC tubes 14 is that it minimizes hydrodynamic drag (which is the resistance to the movement of an object in water) when the PEC system 10 is deployed into and retrieved from the sea. During operation (towing), the underwater PEC system 10 is shaped substantially like a disk, with low drag (hydrodynamic drag) as it "passes" through the seawater. The relatively open structure (perforations) of the PEC system 10 design also minimizes drag and provides space for assembly, maintenance, and general accessibility. This includes allowing remotely operated vehicles (ROVs) to access multiple key maintenance areas of the PEC system 10.

[0100] The terms "comprise", "include", "incorporate", and "have" are used herein to describe an open list of one or more elements or steps, rather than a closed list. When these terms are used, the elements or steps listed in the list do not exclude other elements or steps that may be added to the list.

[0101] Unless the context indicates otherwise, the terms “a” or “an” are used herein to mean at least one of the subsequently mentioned elements, integers, steps, features, operations or components, but do not exclude additional elements, integers, steps, features, operations or components.

[0102] In some cases, the presence of expanded words and phrases such as "one or more," "at least," "but not limited to," or other similar phrases is not intended, and should not be interpreted, to indicate that a narrower scenario is intended or required without the use of such expanded phrases.

[0103] Reference Numbers

[0104] Pressure exchange chamber system 10,

[0105] Pressure exchange chambers 12a, 12b, 12c, 12d, 112, 212, 312

[0106] Pressure exchange chamber tubes 14a, 14b, 14c, 14d; 214a, 214b, 214c, 214d; 314a, 314b, 314c, 314d

[0107] Center frame 16

[0108] Center Core 18

[0109] Lateral support wing 20

[0110] Frame extension (peripheral frame) 22

[0111] Upright grille 24

[0112] Hydraulic power unit 26

[0113] Slurry feed pump 28

[0114] Shut-off valve device 30, 130, 230, 330

[0115] Central part 32 (of the cut-off valve device)

[0116] Slurry input valves 34a, 34b, 34c, 34d

[0117] Slurry output valves 36a, 36b, 36c, 36d

[0118] Side parts 40, 42 (of the cut-off valve device)

[0119] Driving fluid (or water) input valves 44a, 44b, 44c, 44d

[0120] Drive fluid (or water) output valves 46a, 46b, 46c, 46d

[0121] Compression valves 48a, 48b, 48c, 48d

[0122] Pressure reducing valves 50a, 50b, 50c, 50d

[0123] Slurry output pipe connector 60

[0124] Drive fluid riser connector 62

[0125] First driving fluid output pipe 64

[0126] Second driving fluid output pipe 66

[0127] Slurry input pipe 68

[0128] Slurry input manifold 70

[0129] Slurry input connection pipe 72

[0130] Angled pipe sections 74a, 74b, 74c, 74d

[0131] Pulsation Damper 80

[0132] Slurry end of PEC tube 82

[0133] Slurry pipes 84a, 84b, 84c, 84d

[0134] Drive fluid end of PEC tube 86

[0135] Driving fluid pipes 88a, 88b, 88c, 88d

[0136] Slurry inflow arrow 90

[0137] Slurry outflow arrow 92

Claims

1. A pressure exchange chamber, comprising: (i) a pressure exchange chamber tube extending around the periphery; (ii) a driving fluid input valve and a driving fluid output valve, wherein the two valves are enclosed by the pressure exchange chamber tube; as well as (iii) a slurry input valve and a slurry output valve, both valves being enclosed by the pressure exchange chamber tube.

2. The pressure exchange chamber of claim 1, wherein the drive fluid valve and the slurry valve are generally centrally located and surrounded by the pressure exchange chamber tube.

3. The pressure exchange chamber according to claim 1 or 2, wherein the pressure exchange chamber tubes are substantially evenly arranged around the driving fluid valve and / or the slurry valve.

4. The pressure exchange chamber according to any preceding claim, wherein the pressure exchange chamber further comprises a driving fluid input pipe and a slurry input pipe, both pipes being enclosed by the pressure exchange chamber pipe.

5. A pressure exchange chamber according to any preceding claim, wherein the pressure exchange chamber tubes are arranged in a substantially horizontal plane.

6. The pressure exchange chamber according to any preceding claim, wherein the pressure exchange chamber further comprises a driving fluid output pipe and a slurry output pipe, both pipes being enclosed by the pressure exchange chamber pipe.

7. A pressure exchange chamber according to any preceding claim, wherein the pressure exchange chamber tube comprises a thermoplastic composite tube.

8. A pressure exchange chamber system, comprising: Central frame; and a plurality of pressure exchange chambers according to any preceding claim, wherein the pressure exchange chamber tubes are arranged in a stacking plane around the central frame, and each of a plurality of groups of drive fluid input valves and drive fluid output valves and slurry input valves and slurry output valves is associated with a corresponding pressure exchange chamber tube; and the plurality of groups of drive fluid valves and slurry valves are supported by the central frame.

9. The pressure exchange chamber system of claim 8, wherein the pressure exchange chamber tubes are arranged in a substantially horizontal plane and are stacked vertically aligned with each other.

10. The pressure exchange chamber system according to claim 8 or 9, further comprising a driving fluid input pipe and a slurry input pipe.

11. The pressure exchange chamber system according to any one of claims 8 to 10, further comprising a driving fluid output pipe and a slurry output pipe.

12. The pressure exchange chamber system according to claim 11, wherein the driving fluid input pipe and the driving fluid output pipe as well as the slurry input pipe and the slurry output pipe are located within the central frame, close to the center of gravity of the pressure exchange chamber system.

13. The pressure exchange chamber system of claim 12, wherein each actuating fluid input valve and actuating fluid output valve has an associated compression valve and a pressure reducing valve, and the compression valve and the pressure reducing valve are positioned in a straight line with the associated actuating fluid input valve and actuating fluid output valve and are at approximately the same height as the associated actuating fluid input valve and actuating fluid output valve.

14. The pressure exchange chamber system according to any one of claims 8 to 13, further comprising a slurry input manifold, the slurry input manifold comprising an upwardly extending pipe and a plurality of pipe sections extending upwardly and outwardly from the upwardly extending pipe, each pipe section being connected to a corresponding slurry input valve at an upper end.

15. The pressure exchange chamber system of any one of claims 8 to 14, wherein each pressure exchange chamber tube defines a generally rectangular shape having a bend at each of four corners.

16. The pressure exchange chamber system of any one of claims 8 to 15, wherein each pressure exchange chamber tube comprises a thermoplastic composite tube.

17. The pressure exchange chamber system of claim 16, wherein each thermoplastic composite tube comprises a circular cross-section.

18. A hydraulic ore hoisting system comprising a pressure exchange chamber system according to claims 8 to 17.

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