Pressure Exchange Chamber

Abstract

The pressure exchange chamber includes a pressure exchange chamber pipe (12) extending around its periphery, a drive fluid inlet valve (44) and a drive fluid outlet valve (46) both surrounded by the pressure exchange chamber pipe, and a slurry inlet valve (34) and a slurry outlet valve (36) both surrounded by the pressure exchange chamber pipe. Also disclosed is a marine hydraulic ore hoist system (HOHS) including a plurality of such pressure exchange chambers.

Description

[Technical Field]

[0001] The present invention relates to a pressure exchange chamber, particularly but not exclusively, for use in the mining and mineral processing industry, and particularly for use in hydraulic ore hoisting systems (HOHS) located at or near the seabed or lakebed. [Background technology]

[0002] One of the problems in the mineral processing industry relates to transporting ore from underground or seabed locations to surface level. A novel system for such transportation is described in PCT application number PCT / IB2019 / 055957 owned by Wir Minerals Netherlands BV and is called 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 FIG. 1. The pressure exchange chamber system 1 includes multiple pressure exchange chambers 2, 3, and 4 extending over a significant distance, e.g., several tens of meters, between a drive fluid (or water) injection end 5 and a slurry discharge end 6. Each pressure exchange chamber includes a set of water valves 7 at the drive fluid injection end 5 and a set of slurry valves 8 at the slurry discharge end 6. The pressure exchange chambers 2, 3, and 4 are illustrated in FIG. 1 as being linearly arranged. However, when deployed in a deep-sea environment, the pressure exchange chamber system 1 (and thus the pressure exchange chambers 2, 3, and 4) is expected to be lowered through a moonpool (an opening in the hull) and raised from the seabed through the moonpool. The size of the moonpool determines the maximum dimensions of the pressure exchange chamber system 1. It is therefore difficult to design a pressure exchange system that can be installed through a moonpool and still have a chamber length long enough for the HOHS to function effectively (typically greater than 60 m, and sometimes greater than 100 or 150 m).

[0004] Furthermore, for flow assurance and system reliability in HOHS, the pressure exchange chamber is ideally a straight pump chamber located in the same horizontal plane with no height difference between the water inlet end and the slurry outlet end. Pressure exchange chambers with multiple bends increase the breakup of polymetallic nodules transported in the slurry. Slopes or height differences in the pressure exchange chamber increase the risk of blockage within the chamber.

[0005] One embodiment of the present invention has as its object to solve or mitigate the above-mentioned or other problems of the prior art, or to provide a useful alternative to the prior art, or to provide an improved use thereof.

[0006] The various aspects detailed below are independent of one another unless otherwise specified, but features of one aspect may be combined with any of the other aspects to create new aspects unless technically impractical. Any claim corresponding to one aspect should not be construed as incorporating any element or feature of any other aspect unless expressly recited in that claim.

[0007] Any reference in this specification to a prior publication (or information derived from a prior publication) or to publicly known content is not, and should not be construed as, an acknowledgment, agreement, or any form of suggestion that the prior publication (or information derived from the prior publication) or publicly known content forms part of the common general knowledge in the field of the subject matter to which this specification pertains, or is recitable as prior art to the present application. Summary of the Invention

[0008] This Summary is provided to introduce a selection of 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, there is provided a pressure exchange chamber comprising: (i) a pressure exchange chamber pipe extending around the periphery; (ii) a drive fluid inlet valve and a drive fluid outlet valve, both of which are surrounded by the pressure exchange chamber pipe; and (iii) a slurry inlet valve and a slurry outlet valve, both of which are surrounded by the pressure exchange chamber pipe.

[0010] The pressure exchange chamber pipe may be configured to extend completely around the entire periphery so as to completely surround the drive fluid valve and the slurry valve, or the pressure exchange chamber pipe may extend around most of the periphery so as to substantially surround these valves (leaving only a relatively small gap).

[0011] The drive fluid valve and the slurry valve may be located approximately centrally within the pressure exchange chamber pipe, or the slurry injection valve may be located centrally, with the drive fluid valves located on either side of the slurry injection valve.

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

[0013] The pressure exchange chamber pipes may be substantially evenly spaced around the drive fluid valve and / or slurry valve, thereby providing an approximate center of gravity for the pressure exchange system. The approximate center of gravity facilitates deployment of the pressure exchange chamber through a moonpool on a surface vessel or from another type of floating system. By having an approximate center of gravity, the hook-up attachments connected to the risers extending from the pressure exchange chamber minimize tilt 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 further comprise a drive fluid riser coupling and a slurry injection pipe, both pipes being surrounded by the pressure exchange chamber pipe.

[0015] The pressure exchange chamber may further comprise a drive fluid discharge pipe and a slurry discharge pipe, both of which are surrounded by the pressure exchange chamber pipe and may optionally be connected to part of the valve.

[0016] According to a second aspect of the present invention, there is provided a pressure exchange chamber system comprising a central frame and a plurality of pressure exchange chambers according to the first aspect, the pressure exchange chamber pipes being arranged in a plane stacked around the central frame, each of a plurality of sets of drive fluid injection and discharge valves and slurry injection and discharge valves being associated with a corresponding pressure exchange chamber pipe, and the plurality of sets of drive fluid valves and slurry valves being supported by the central frame.

[0017] The pressure exchange chamber pipes are preferably arranged in a generally horizontal plane stacked vertically on top of one another, which will reduce the risk of blockages as the bends in the pipes are in a horizontal plane and preferably have the same diameter.

[0018] Optionally, the pressure exchange chamber system may include a drive fluid injection pipe and a slurry injection pipe. The drive fluid injection pipe may include or be connected to a marine pipe (or riser) extending from the ocean surface to the pressure exchange chamber system. The slurry injection pipe may be connected to a slurry supply pump.

[0019] Optionally, the pressure exchange chamber system may include a drive fluid discharge pipe and a slurry discharge pipe, which may include or be connected to a marine riser extending from the pressure exchange chamber system to the ocean surface.

[0020] The drive fluid and slurry inlet and outlet pipes may be located within a central frame near the center of gravity of the pressure exchange chamber system, thereby facilitating deployment of the pressure exchange chamber system through moonpools on surface vessels such as ships, and aiding in recovery of the system through moonpools of the same size.

[0021] Each drive fluid inlet and outlet valve (of the same PEC) may have an associated compression valve and pressure reducing valve, which may be located alongside and at approximately the same height as the associated drive fluid inlet and outlet valves.

[0022] Each drive fluid inlet and outlet valve (of the same PEC) may be located at the same vertical position (height) as the corresponding slurry outlet valve and at the same vertical position (height) as the corresponding slurry inlet valve. Alternatively, each drive fluid inlet and outlet valve (of the same PEC) may be vertically offset from the corresponding slurry outlet and inlet valves.

[0023] One set of drive fluid valves (for the same PEC) may be located in a similar vertical position as another set of drive fluid valves (for another PEC).

[0024] One set of drive fluid valves (for the same PEC) may be vertically offset from another set of drive fluid valves (for another PEC), and similarly, one set of slurry valves may be vertically offset from another set of slurry valves.

[0025] The pressure exchange chamber system may optionally include a drive fluid inlet manifold, a drive fluid outlet manifold, a slurry inlet manifold, and a slurry outlet manifold.

[0026] The drive fluid injection manifold may comprise a vertically extending pipe and a plurality of pipe segments extending downwardly therefrom, each of the downwardly extending pipe segments being connected at its lower end to a respective drive fluid injection valve.

[0027] The slurry inject valve may be centrally located and the drive fluid valves may be located on either side of the slurry inject valve, thereby minimizing the length of the common slurry inject manifold.

[0028] The drive fluid discharge manifold may comprise a vertically extending pipe and a plurality of pipe segments extending upwardly therefrom, each of the upwardly extending pipe segments being connected at its upper end to a respective drive fluid discharge valve.

[0029] The slurry injection manifold may include a vertically extending pipe with multiple pipe segments extending upward therefrom, each connected at its upper end to a respective slurry injection valve. By having the pipe segments oriented upward toward the slurry injection valve, when the slurry injection flow is stopped, any slurry in the pipe segments will flow downward (as a result of gravity) and away from the slurry injection valve. This reduces the risk of clogging the slurry injection valve.

[0030] The slurry discharge manifold may comprise a vertically extending pipe and a plurality of pipe segments extending downwardly therefrom, each of the downwardly extending pipe segments being connected at its lower end to a respective slurry discharge valve.

[0031] Each pressure exchange chamber pipe may be configured to define a generally rectangular (and in some embodiments, generally square) shape with bends at the corners to reduce particle size degradation, pipe wear, and blockages.

[0032] Each pressure exchange chamber pipe may comprise a thermoplastic composite pipe (TCP). Alternatively, each pressure exchange chamber pipe may comprise a metal (e.g., steel) pipe. Advantages of TCP include lighter weight than steel, corrosion resistance, and improved flexibility in bending the pipe compared to metal.

[0033] Optionally, each TCP may have a circular cross section.

[0034] Each pressure exchange chamber pipe may be coated on its inner surface with a wear resistant coating.

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

[0036] The pressure exchange chamber system may be configured with a footprint of approximately 10m x 20m (length x width) for its outer dimensions.

[0037] The pressure exchange chamber system may further comprise one or more hydraulic power units and slurry feed pumps (multiples of one or both may be provided for redundancy purposes), a control cabinet, a pressure relief system, flow sensors, flotation, thrust positioners for moving the pressure exchange chamber system, etc. The power units and pumps may be marine-specified to allow operation on or near the seabed.

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

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

[0040] It will now be appreciated that improved balance and geometry can provide a pressure exchange system that can be easily deployed through moonpools on sea or lake surface vessels.

[0041] One advantage of a rectangular shaped PEC system is that the contour or shape is substantially the same as the contour or shape of a typical mining vessel moonpool, which means that the PEC system can be handled and transported on and around the deck of a mining vessel, and into a moonpool, typically using known subsea equipment handling systems, such as transports, guidance systems, carriers, etc.

[0042] According to a fourth aspect, there is provided a pressure exchange chamber comprising: (i) a pressure exchange chamber pipe extending in a substantially horizontal plane and defining an enclosure; (ii) a drive fluid injection valve and a drive fluid discharge valve; and (iii) a slurry injection valve and a slurry discharge valve, the drive fluid valve and the slurry valve being located in close proximity to each other.

[0043] The drive fluid valves and the slurry valves may all be located within the pressure exchange pipe enclosure, or alternatively, the drive fluid valves and the slurry valves may all be located outside the pressure exchange pipe enclosure.

[0044] According to a fifth aspect of the present invention, there is provided a pressure exchange chamber system comprising a plurality of pressure exchange chambers according to the fourth aspect, wherein the pressure exchange chamber pipes are arranged in vertically spaced-apart stacked planes, and each of a plurality of sets of drive fluid injection and discharge valves and slurry injection and discharge valves is associated with a respective pressure exchange chamber pipe.

[0045] The pressure exchange chamber pipes may be arranged in two or more vertically spaced stacked planes separated horizontally from each other.

[0046] The slurry inlet and outlet valves may be surrounded by one set of vertically spaced, stacked flat surfaces, and the drive fluid inlet and outlet valves may be surrounded by another set of vertically spaced, stacked flat surfaces.

[0047] Alternatively, the slurry inlet and outlet valves and the drive fluid inlet and outlet valves may be located between two adjacent vertically spaced apart stacked flat surfaces.

[0048] The above and other aspects will become apparent from the following detailed description, given by way of example only, when taken in conjunction with the accompanying drawings, in which: [Brief explanation of the drawings]

[0049] [Figure 1] FIG. 1 is a simplified schematic diagram of a prior art pressure exchange chamber system. [Figure 2] FIG. 2 is a simplified cutaway perspective view of a pressure exchange chamber system according to a first embodiment of the present invention mounted on a frame with auxiliary units. [Figure 3] FIG. 3 is a simplified schematic plan view of the components (drive fluid valve, compression valve, pressure reduction valve, and slurry valve) shown in the pressure exchange chamber system of FIG. [Figure 4]FIG. 4 is a simplified schematic plan view of the valves shown in FIG. 3, including their interconnections. [Figure 5] FIG. 5 is a simplified perspective view of the valve of FIG. [Figure 6] FIG. 6 is an external perspective view of a slurry injection manifold for the slurry valve of FIGS. [Figure 7] FIG. 7 is a plan view of a part (one of the pressure exchange chamber pipes) of the pressure exchange chamber system of FIG. [Figure 8] FIG. 8 is a perspective view of the pressure exchange chamber pipe of FIG. [Figure 9] 9 is a perspective view of the exterior of the pressure exchange chamber of the pressure exchange chamber system of FIG. 2. FIG. [Figure 10] Figure 10A is a perspective view of the valve of Figure 5 with one (highest) pressure exchange chamber pipe connected, Figure 10B is a perspective view of the valve of Figure 5 with another (second highest) pressure exchange chamber pipe connected, Figure 10C is a perspective view of the valve of Figure 5 with yet another (second lowest) pressure exchange chamber pipe connected, and Figure 10D is a perspective view of the valve of Figure 5 with yet another (lowest) pressure exchange chamber pipe connected. [Figure 11] FIG. 11 is a simplified perspective view of an exterior of another embodiment of the pressure exchange chamber. [Figure 12] FIG. 12 is a simplified perspective exterior view of yet another embodiment of a pressure exchange chamber. [Figure 13] FIG. 13 is a simplified perspective exterior view of yet another embodiment of a pressure exchange chamber. DETAILED DESCRIPTION OF THE INVENTION

[0050] Referring first to FIG. 2, FIG. 2 is a simplified, partially cutaway, perspective exterior view of a pressure exchange chamber (“PEC”) system 10 according to a first embodiment of the present invention. The PEC system 10 includes multiple pressure exchange chambers (“PECs”) 12a, 12b, 12c, and 12d. In this embodiment, four PECs 12a, 12b, 12c, and 12d are provided. Typically, only three of these PECs (e.g., 12a, 12b, and 12c) are used, with a fourth PEC (e.g., 12d) provided as a spare in case one of the three PECs (12a, 12b, and 12c) fails. This provides redundancy for continued operation, which is important because the PEC system 10 can be difficult to repair in the field on the seabed. The PECs are designed for use in deepwater environments and may be coupled to the bottom of a riser, umbilical, or cable, or the like.

[0051] Each PEC 12a, 12b, 12c, 12d comprises a PEC pipe 14a, 14b, 14c, 14d extending circumferentially in a generally rectangular spiral shape (a spiral having generally straight sides and bending at the ends of the straight sides). The rectangular spiral shape may, in some embodiments, be configured as a square spiral. The PEC pipes 14a, 14b, 14c, 14d are arranged in vertically spaced, stacked planes (each plane is generally horizontal) around a central frame 16. In this embodiment, the central frame 16 comprises a welded steel beam, although other embodiments may use different materials and couplings.

[0052] The central frame 16 includes a cubic central core 18 having lateral support wings 20 (only one shown) extending therefrom, and frame extensions (also referred to as peripheral frameworks) 22 cantilevered from the lateral support wings 20. The frame extensions 22 support a plurality of upright lattices 24 spaced about the perimeter framework 22, each lattice 24 defining an array of spaces. Corresponding spaces within the upright lattices 24 are aligned such that a PEC pipe (e.g., 14a) is routed through the aligned spaces within the upright lattice 24. Each lattice space supports one or more PEC pipes 14, with typically two PEC pipes (e.g., 14a and 14b) routed through each lattice space.

[0053] Each PEC pipe 14 comprises thermoplastic composite pipe (TCP), extends for approximately 160m and has a footprint of approximately 30m x 20m (length x width) for its external dimensions.

[0054] The PEC system 10 further includes a hydraulic power unit 26 and a slurry feed pump 28 (for feeding slurry into the PEC pipe 14). Both the hydraulic power unit 26 and the feed pump 28 are coupled to the central frame 16 and are designed to operate in a deep seawater environment (i.e., are marine-qualified). In this embodiment, two hydraulic power units 26 and two slurry feed pumps 28 are provided in case one fails during use, although these additional units are not shown in the drawings.

[0055] Each PEC 12a, 12b, 12c, 12d also includes a respective valve, which will be described in detail with reference to Figures 3-6. The valves are disposed within a block valve arrangement 30, the central portion 32 of which has slurry valves (four slurry inlet valves 34a, 34b, 34c, 34d and four slurry outlet valves 36a, 36b, 36c, 36d, one for each PEC) located within the cubic central core 18.

[0056] The block valve arrangement 30 has two sides 40, 42. The sides 40, 42 are mounted on opposite lateral support wings 20.

[0057] The first side 40 includes two drive fluid (or water) inlet valves 44a, 44b, two drive fluid (or water) outlet valves 46a, 46b, two compression valves 48a, 48b, and two pressure reducing valves 50a, 50b.

[0058] Similarly, the second side 42 includes two drive fluid (or water) inlet valves 44c, 44d, two drive fluid (or water) outlet valves 46c, 46d, two pressure reducing valves 48c, 48d, and two pressure reducing valves 50c, 50d.

[0059] The valves on the second side 42 are generally located at a higher level (i.e., above) than the valves on the first side 40 (best shown in FIG. 5) and are positioned as a mirror image relative to the valves on the first side 40.

[0060] The block valve arrangement 30 is used to control the pressure and fluid flow rate within the PEC pipe 14 (i.e., first allowing the slurry feed pump 28 to fill the PEC pipe 14, and then allowing the PD pump to drive the slurry from the PEC pipe).

[0061] 4, the inlet and outlet of each PEC 12a, 12b, 12c, 12d are located in one of the quadrants of the block valve arrangement 30. The inlet and outlet of the first PEC 12a are in the upper left quadrant, the inlet and outlet of the second PEC 12b are in the lower left quadrant, the inlet and outlet of the third PEC 12c are in the lower right quadrant, and the inlet and outlet of the fourth PEC 12d are in the upper right quadrant.

[0062] A single slurry discharge pipe coupling 60 is located within the central section 32 and extends upward to reach and connect the slurry pumped out of the PEC system 10 to a riser (not shown) that supplies, for example, a dewatering system located on the deck of a vessel at the sea surface. Similarly, a single motive fluid riser coupling 62 is located within the central section 32 and extends upward to reach and connect to a motive fluid riser (not shown) that connects to a pump (not shown) on the sea surface. The single motive fluid riser coupling 62 may be connected to a riser-type pipe that extends to the sea surface.

[0063] A first drive fluid discharge pipe 64 is provided at the first and second PEC valves (i.e., the first and second quadrants) and extends downward therefrom. Similarly, a second drive fluid discharge pipe 66 is provided at the third and fourth PEC valves (i.e., the third and fourth quadrants) and extends downward therefrom. These drive fluid discharge pipes 64, 66 are best illustrated in FIG. 5. In other embodiments, they may be combined into a single drive fluid discharge pipe.

[0064] A single slurry injection pipe 68 (best seen in FIG. 5) is located within the central section 32 and connects to the four slurry injection valves 34a, 34b, 34c, 34d through a slurry injection manifold 70 (best seen in FIG. 6). The single slurry injection pipe 68 is connected to a slurry feed pump 28 that fills the PEC pipe 14 with slurry.

[0065] The slurry injection manifold 70 includes a slurry injection connection pipe 72 (which connects to the slurry injection pipe 68) and a plurality of angled pipe segments 74a, 74b, 74c, and 74d extending upwardly and outwardly therefrom. Each upwardly angled pipe segment 74a, 74b, 74c, and 74d is connected at its upper end to a respective slurry injection valve 34a, 34b, 34c, and 34d. When the slurry injection flow is stopped, by orienting the pipe segments 74a, 74b, 74c, and 74d in an upward (and outward) direction toward the slurry injection valves 34a, 34b, 34c, and 34d, any slurry within the pipe segments 74 will flow downward (as a result of gravity) and away from the associated slurry injection valve 34. This reduces the risk of the slurry inlet valves 34a, 34b, 34c, 34d clogging or damaging the valves when they are closed.

[0066] The operation (eg, opening and closing) of the various valves within the block valve arrangement 30 is controlled by the subsea hydraulic power unit 26 .

[0067] The pulse damper 80 is also provided on the single drive fluid injection pipe 62 (best seen in Figures 4 and 5). This configuration can be implemented using a common drive fluid manifold that supplies four PECs 12.

[0068] 7 and 8, which show two views of one of the PEC pipes 14a. One end of the PEC pipe 14a is a slurry end 82 connected to a slurry pipe 84a. The slurry pipe 84a is connected to both a slurry inlet valve 34a (which is open when the PEC pipe 14a is filling with slurry) and a slurry outlet valve 36a (which is open when slurry is being discharged from the PEC pipe 14a and raises the slurry outlet pipe coupling 60 to the riser). The other end of the PEC pipe 14a is a motive fluid end 86 connected to a motive fluid pipe 88a. The motive fluid pipe 88a is connected to both a motive fluid inlet valve 44a (which is open when slurry is being discharged from the PEC pipe 14a and raises the slurry outlet pipe coupling 60 to the riser) and a motive fluid outlet valve 46a (which is open when the PEC pipe 14a is filling with slurry). Arrows 90 indicate the direction of slurry flow into the PEC pipe 14a, and arrows 92 indicate the direction of slurry flow out of the PEC pipe 14a toward the slurry discharge pipe 60. The PEC pipe 14a rises (slopes) at the drive fluid end 86 and then extends in a rectangular spiral shape in the horizontal plane. Having a sloped section at the drive fluid end 86 reduces the risk of clogging because it is primarily the drive fluid (which does not contain nodules or large particles) that passes through this section, rather than the slurry.

[0069] 9 is an external perspective view showing four PEC pipes 14a, 14b, 14c, and 14d from FIG. 2 stacked vertically and surrounding a block valve arrangement 30. The PEC pipes 14 are spaced substantially evenly around the block valve arrangement 30, thereby ensuring that the PEC system 10 has a center of gravity close to its geometric center. This facilitates deployment of the PEC system 10 through a moonpool on 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.

[0070] PEC system 10 includes multiple (four in this embodiment) PECs 12a, 12b, 12c, 12d arranged in stacked planes that are vertically offset from one another. This is best shown in Figures 10A-10D, which are perspective views similar to that of Figure 9, each showing only one of the PEC pipes 14a, 14b, 14c, 14d in isolation for added clarity.

[0071] Each PEC pipe 14a, 14b, 14c, 14d is positioned in a generally horizontal plane. Each chamber pipe 14a, 14b, 14c, 14d rises slightly from its respective drive fluid end 86a, 86b, 86c, 86d to the level of its respective slurry end 82a, 82b, 82c, 82d to provide space for the pipes 14 to encircle the block valve arrangement 30 in a generally rectangular spiral shape (a spiral shape having generally straight sides and bending at the ends of the straight sides). In this embodiment, each PEC pipe 14a, 14b, 14c, 14d rises to the level of its respective drive fluid end 86a, 86b, 86c, 86d before the first bend of the PEC pipe 14a, 14b, 14c, 14d.

[0072] It should be appreciated that this PEC system 10 has the advantages of (i) a center of gravity near the center of the PEC system 10, (ii) a relatively small footprint while allowing the PEC pipes 14 to be very long, and (iii) a relatively small number of bends within each PEC pipe 14.

[0073] It will be understood that other PEC system configurations are possible within the scope of the claims. For example, Figure 11 shows another configuration of PEC 112 (simplified for clarity by removing the compression and pressure reducing valves) in which the block valve configuration 130 is different, but the PEC pipes 14a, 14b, 14c, 14d are the same as or very similar to the configuration of PEC system 10.

[0074] 12 shows a third PEC system 212 in which the block valve configuration 230 is different and the PEC pipes 214a, 214b, 214c, and 214d are different from those of the PEC system 10. The block valve configuration 230 is divided so that the slurry inlet valve 234 and the slurry outlet valve 236 are located as a block 230a within and surrounded by two PEC pipes 214a and 214b, and the drive fluid inlet valve 244 and the drive fluid outlet valve 246 are located as a block 230b within and surrounded by the other two PEC pipes 214c and 214d. The PEC system 212 has the advantage that each pipe 214a, 214b, 214c, and 214d can extend in the same plane without any changes in height (i.e., no height differences along the PEC pipes 214).

[0075] 13 shows a fourth PEC system 312 in which a block valve arrangement 330 is centrally located between two sets of PEC pipes: the first set includes two PEC pipes 314a, 314b, and the second set includes two PEC pipes 314c, 314d.

[0076] In use, the PEC system 10 is located near the seabed or lakebed (e.g., tens of meters above the seabed or lakebed), which results in an elevation significantly lower than the final delivery point (e.g., the ocean surface) to which the slurry is delivered. The PEC system 10 may be freely suspended (via a riser) from a ship (or other vessel) above the ocean surface. In this embodiment, the slurry contains ore particles (also referred to as polymetallic nodules) ranging in size from 10 to 200 mm in a liquid carrier, producing a slurry of entrained and suspended ore particles.

[0077] In this embodiment, each PEC pipe 14 comprises a thermoplastic composite pipe (TCP), although in other embodiments the pipes may be made from different materials or composites, and the inner surface of the PEC pipe 14 may have a wear-resistant or low-friction coating. Advantages of using TCP for the PEC pipe 14 include being lighter than steel or other metals, being corrosion-resistant and wear-resistant, and being more flexible when forming bends than metals.

[0078] In this embodiment, each PEC pipe 14 is approximately 160 m long, although different pipe lengths may be used in other embodiments.

[0079] It will now be appreciated that prior art hydraulic ore hoist systems can be upgraded by replacing the PEC system with PEC system 10.

[0080] It will now be appreciated that a PEC system can be provided that is easily deployed through a moonpool on a surface vessel at sea or on a lake, with improved balance and geometry.

[0081] Another advantage of the PEC system 10 is its compactness and symmetry, which facilitates ease of handling and transport on and around mining vessels (e.g., offshore vessels) and through the vessel's moonpool.

[0082] Another advantage of the PEC system 10 is that all valves of one PEC pipe (eg, 14 a ) are located in the same quadrant of the block valve configuration 30 , which minimizes the overall height of the PEC system 10 .

[0083] A common slurry injection manifold allows for a reduced height of the PEC 12, thereby reducing the volume of settled solids from the slurry.

[0084] Another advantage of the vertical in-line stack PEC pipe 14 is that it minimizes hydrodynamic drag (the resistance to movement of a submerged object) when moving the PEC system 10 in and out of the ocean. During operation (tow), the shape of the subsea PEC system 10 behaves essentially like a disk, with low resistance (hydrodynamic drag) as it "cuts" through the seawater. The relatively open (perforated) structure 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 many of the PEC system 10's key maintenance areas.

[0085] The terms "comprising," "including," "incorporating," and "having" are used in this disclosure to describe an open-ended list of one or more elements or steps, rather than an exclusive list. When such terms are used, the elements or steps described in the list do not exclude other elements or steps that may be added to the list.

[0086] Unless the context indicates otherwise, the terms "a" and "an" are used herein to indicate 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.

[0087] The presence of broadening words or phrases, such as "one or more," "at least," "without limitation," or other similar words or phrases, does not imply, and should not be construed as, that a narrower scope is intended or required when such broadening words or phrases are not used. [Explanation of symbols]

[0088] 10: Pressure exchange chamber system 12a, 12b, 12c, 12d, 112, 212, 312: Pressure exchange chamber 14a, 14b, 14c, 14d, 214a, 214b, 214c, 214d, 314a, 314b, 314c, 314d: Pressure exchange chamber pipe 16: Center frame 18: Central Core 20: Lateral support wing 22: Frame extension (peripheral framework) 24:Upright lattice 26: Hydraulic power unit 28: Slurry supply pump 30, 130, 230, 330: Block valve configuration 32: Central part (of block valve configuration) 34a, 34b, 34c, 34d: Slurry injection valves 36a, 36b, 36c, 36d: Slurry discharge valves 40, 42: Sides (of block valve configuration) 44a, 44b, 44c, 44d: Driving fluid (or water) injection valve 46a, 46b, 46c, 46d: Driving fluid (or water) discharge valve 48a, 48b, 48c, 48d: Compression valves 50a, 50b, 50c, 50d: Pressure reducing valve 60: Slurry discharge pipe coupling 62: Drive fluid riser coupling 64: First driving fluid discharge pipe 66: Second driving fluid discharge pipe 68: Slurry injection pipe 70: Slurry injection manifold 72: Slurry injection connection pipe 74a, 74b, 74c, 74d: Angled pipe segments 80: Pulse damper 82: Slurry end of PEC pipe 84a, 84b, 84c, 84d: Slurry pipes 86: Driving fluid end of PEC pipe 88a, 88b, 88c, 88d: driving fluid pipes 90: Slurry injection flow arrow 92: Slurry discharge flow arrow

Claims

1. a pressure exchange chamber, (i) a peripherally extending pressure exchange chamber pipe; (ii) a drive fluid inlet valve and a drive fluid outlet valve, both of which are surrounded by said pressure exchange chamber pipe; (iii) a pressure exchange chamber assembly comprising a slurry inlet valve and a slurry outlet valve, both of which are surrounded by said pressure exchange chamber pipe.

2. 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 pipe.

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

4. The pressure exchange chamber according to any one of claims 1 to 3, further comprising a drive fluid injection pipe and a slurry injection pipe, both of which are surrounded by the pressure exchange chamber pipe.

5. The pressure exchange chamber according to any one of claims 1 to 4, wherein the pressure exchange chamber pipe is arranged in a substantially horizontal plane.

6. The pressure exchange chamber according to any one of claims 1 to 5, further comprising a driving fluid discharge pipe and a slurry discharge pipe, both of which are surrounded by the pressure exchange chamber pipe.

7. A pressure exchange chamber according to any one of claims 1 to 6, wherein the pressure exchange chamber pipe comprises a thermoplastic composite pipe.

8. 8. A pressure exchange chamber system comprising: a central frame; and a plurality of pressure exchange chambers according to any one of claims 1 to 7, wherein the pressure exchange chamber pipes are arranged in a stacked plane around the central frame, each of the plurality of sets of drive fluid injection and discharge valves and slurry injection and discharge valves is associated with a respective pressure exchange chamber pipe, and the plurality of sets 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 pipes are arranged in generally horizontal planes stacked vertically on top of each other.

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

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

12. The pressure exchange chamber system of claim 11 , wherein the drive fluid and slurry inlet and outlet pipes are located within the central frame near the center of gravity of the pressure exchange chamber system.

13. 13. The pressure exchange chamber system of claim 12, wherein each drive fluid injection valve and discharge valve has an associated compression valve and pressure reduction valve, and the associated compression valves and pressure reduction valves are located side by side with the associated drive fluid injection valves and discharge valves at approximately the same height.

14. 14. The pressure exchange chamber system of claim 8, further comprising a slurry injection manifold comprising an upwardly extending pipe and a plurality of pipe segments extending upwardly and outwardly therefrom, each pipe segment connected at an upper end to a respective slurry injection valve.

15. A pressure exchange chamber system according to any one of claims 8 to 14, wherein each pressure exchange chamber pipe defines a generally rectangular shape with bends at each of the four corners.

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

17. The pressure exchange chamber system of claim 16 , wherein each thermoplastic composite pipe has a circular cross section.

18. A hydraulic ore hoist system comprising a pressure exchange chamber system according to any one of claims 8 to 17.

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