Apparatus for separating nodular material from non-nodular material and for removing material from the bottom of a body of water

Abstract

A vehicle (6) apparatus for removing material from the seabed is disclosed. The vehicle comprises a first propulsion unit (10) for moving the vehicle vertically and a second propulsion unit (12) for moving the vehicle horizontally. A collection unit (16) removes material from the seabed and a latching mechanism (42) is adapted to be coupled to the riser to allow transport of the removed material to a vessel above the water surface.

Description

[Technical Field]

[0001] The present disclosure relates to an apparatus for removing material from the bottom of a body of water, and particularly, but not exclusively, to an apparatus for removing nodular material from the ocean floor. [Background technology]

[0002] Nodules of material containing minerals and rare metals form on the seabed at great depths, and it is known to mine such material using mining equipment that rests on the seabed and is powered from a surface vessel via an umbilical cable, the equipment being connected to a conduit known as a jumper hose, through which the nodule material is pumped by a riser pump to the surface vessel.

[0003] Known devices of this type have several drawbacks. First, a human operator or remotely operated vehicle (ROV) must assist in connecting the device to the jumper hose. Furthermore, the weight of the device is supported by the umbilical cable when the device is lowered from the surface vessel to the seabed and then raised from the seabed, necessitating significant mechanical reinforcement of the umbilical cable. The mechanical reinforcement required for the umbilical cable typically has poor heat transfer properties, resulting in heating of the umbilical cable insulation, which further limits the power that can be supplied to the device. Furthermore, the catenary curve of the reinforced umbilical cable is similar to that of the jumper hose used to transport nodule material to the surface, resulting in a risk of collision between the umbilical cable and the conduit during operation of the device. A further drawback of such known devices is the difficulty of operating the device on very soft seabeds. Summary of the Invention [Problem to be solved by the invention]

[0004] It is an aim of preferred embodiments of the present disclosure to overcome one or more of the above drawbacks. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, there is provided an apparatus for separating nodule material from non-nodule material, comprising at least one vessel for receiving a liquid containing nodule material and non-nodule material, at least one respective inlet for allowing the liquid containing nodule material and non-nodule material to enter the at least one vessel, at least one respective first outlet for allowing the liquid to exit the at least one vessel, and at least one respective second outlet for allowing the liquid to exit the at least one vessel, wherein the at least one second outlet is positioned higher than the at least one first outlet on the corresponding vessel, such that entry of the liquid into the vessel via the at least one inlet reduces the velocity of the liquid.

[0006] Providing at least one respective second outlet for allowing liquid to exit at least one said vessel, wherein at least one said second outlet is located at a higher position than at least one said first outlet provided on the corresponding said vessel, has the advantage that entry of liquid into the vessel via at least one said inlet allows the liquid velocity to be reduced so that the concentration of nodule material in the liquid exiting at the first outlet is increased and the concentration of non-nodule material in the liquid exiting at the second outlet is increased. In the case of removing nodule material from the seabed, this has the further advantage of reducing the amount of unwanted non-nodule material removed to a surface vessel, thereby mitigating the environmental impact of returning removed non-nodule material to the seabed by enabling transport of such non-nodule material to land, for example.

[0007] The apparatus may further comprise barrier means for blocking a shortest path from at least one said inlet to at least one said second outlet.

[0008] This has the advantage that it is more difficult for nodule material to reach the second outlet than non-nodule material, thereby minimizing loss of nodule material and increasing the concentration of nodule material in the vicinity of at least one first outlet.

[0009] The barrier means may consist of at least one plate.

[0010] The barrier means may allow liquid to move from said at least one inlet to said at least one second outlet by passing under said barrier means.

[0011] This has the advantage that the nodule material can be forced towards the at least one first outlet while making it more difficult for the nodule material to reach the second outlet, thereby minimizing loss of nodule material and increasing the concentration of nodule material in the vicinity of the at least one first outlet.

[0012] The apparatus may further comprise flow redirection means for redirecting liquid flow towards said at least one first outlet.

[0013] This provides the advantage of increasing the concentration of nodule material in the vicinity of the first outlet(s) while minimizing turbulence, thereby providing better control of the process for separating nodule material from non-nodule material.

[0014] The flow redirection means may comprise a curved surface.

[0015] At least one said container may comprise a respective body tapering towards at least one said first outlet.

[0016] This provides the advantage of increasing the concentration of nodule material in the vicinity of the first outlet(s), thereby increasing the efficiency of the process for separating nodule material from non-nodule material.

[0017] At least one of the containers may include a lower surface that slopes towards the at least one first outlet.

[0018] This has the advantage of increasing the concentration of nodule material in the vicinity of the first outlet(s), thereby increasing the efficiency of the process for separating nodule material from non-nodule material, particularly when the apparatus is vibrating during use.

[0019] The at least one inlet may be oriented toward a substantially central portion of the vessel, in a direction transverse to a direction extending from the at least one inlet to the at least one first outlet.

[0020] This has the advantage of concentrating the nodule-containing liquid stream towards one or more first outlets while minimizing turbulence, thereby increasing the efficiency of the process for separating nodule material from non-nodule material.

[0021] At least one of the inlets may define a nozzle.

[0022] This has the advantage of helping to reduce the velocity of the liquid containing the nodule and non-nodule material, thereby aiding the sorting process.

[0023] The apparatus may further comprise pump means for pumping liquid into at least one said inlet and / or from at least one said first outlet and / or from at least one said second outlet.

[0024] According to another aspect of the present disclosure, there is provided an apparatus for removing nodule material from the bottom of a body of water, the apparatus comprising: movement means for moving the apparatus relative to the bottom of the body of water, material removal means for removing nodule material from the bottom of the body of water, connector means adapted to be connected to a conduit to enable transport of said removed nodule material to a vessel on the surface of the body of water, and apparatus for separating nodule material from non-nodule material as defined above.

[0025] According to a further aspect of the present disclosure, there is provided an apparatus for removing material from the bottom of a body of water, the apparatus comprising first movement means for moving the apparatus in a substantially vertical direction relative to the bottom of the body of water, second movement means for moving the apparatus in a substantially horizontal direction relative to the bottom of the body of water, material removal means for removing material from the bottom of the body of water, and connector means adapted to be connected to a conduit to enable transport of the removed material to a vessel above the surface of the body of water.

[0026] Providing a first means for moving the apparatus substantially vertically relative to the bottom of the body of water and a second means for moving the apparatus substantially horizontally relative to the bottom of the body of water provides several significant advantages. First, no human or remotely operated vehicle (ROV) assistance is required to enable connection of the apparatus to the conduit. The first means for moving the apparatus further provides the advantage of allowing the apparatus to operate more efficiently on very soft seabeds. Another advantage is that the apparatus can be deployed to the seabed without the use of a taut umbilical, thereby reducing the need for reinforcement of the umbilical, thereby allowing more power to be provided to the apparatus via the umbilical, and allowing the apparatus to be deployed at greater distances from the surface vessel. Another advantage is that the apparatus can be more quickly replaced for maintenance, and the apparatus can be maneuvered more easily and without the use of an umbilical, thereby allowing for more efficient material removal.

[0027] The first locomotion means may comprise at least one propulsion unit.

[0028] The second locomotion means may include at least one propulsion unit.

[0029] The second locomotion means may include a plurality of tracks.

[0030] This provides the advantage of allowing the device to be steered on very soft seabeds.

[0031] The device may further comprise buoyancy means for reducing the weight of the device in water.

[0032] This has the advantage of assisting the operation of the first movement means, and also has the advantage that the need for mechanical reinforcement of the umbilical cable is reduced, resulting in less heating of the umbilical cable insulation, allowing for greater power delivery, and the different catenary curve of the umbilical cable with lower mechanical reinforcement also makes it easier to separate the umbilical cable from the conduit, thereby minimizing the possibility of a collision occurring between the umbilical cable and the conduit during operation of the device.

[0033] The apparatus may further comprise a containment means for containing the removed material prior to transport to the vessel.

[0034] According to a further aspect of the present disclosure, there is provided an apparatus for removing nodule material from the bottom of a body of water, the apparatus comprising: movement means for moving the apparatus relative to the bottom of the body of water; material removal means for removing nodule material from the bottom of the body of water; and connector means adapted to be connected to a conduit to enable transport of said removed nodule material to a vessel on the surface of the body of water. The material removal means comprises at least one inlet and seabed engagement means for engaging the bottom of the body of water, the seabed engagement means being positioned forward of said at least one inlet in a direction of movement of the apparatus and comprising a plurality of protrusions adapted to extend substantially in the direction of movement of the apparatus.

[0035]

[0010] Providing seabed engaging means comprising a plurality of protrusions arranged forward of at least one said inlet in the direction of movement of the apparatus and adapted to extend substantially in the direction of movement of the apparatus has the advantage of allowing collection of nodule material on the surface of the seabed while minimizing disturbance of the seabed and thereby minimizing the environmental impact of removing the nodule material. Lower disturbance of the seabed has the further advantage of reduced resistance which results in lower energy consumption.

[0036] The protrusions may include a plurality of teeth.

[0037] The apparatus may further comprise at least one first aperture positioned rearward of said at least one inlet in the direction of movement of the apparatus for allowing passage of nodular material.

[0038] This has the advantage of preventing the inlet from becoming clogged with nodular material in the event that the device is unable to remove the nodular material into the conduit.

[0039] The apparatus may further comprise sorting means positioned adjacent said at least one inlet for sorting nodule material from non-nodule material at the bottom of the body of water.

[0040] By providing a separation means for separating nodule material from non-nodule material at the bottom of a body of water, the amount of unwanted non-nodule material, e.g., sediment, at the bottom of the body of water that is transported to the surface is minimized, thereby minimizing energy consumption and avoiding the environmental impact of returning to the seabed non-nodule material that was previously removed to the surface.

[0041] The screening means may comprise at least one surface which, in use, is inclined relative to the bottom of the body of water and has at least one second aperture for allowing non-nodule material to pass and preventing the passage of said nodule material.

[0042] The apparatus may further comprise suction means for removing nodular material from at least one of said inlets.

[0043] The suction means may be adapted to reverse the direction of water flow past the suction means.

[0044] This has the advantage of aiding in clearing blockages.

[0045] Embodiments will now be described, by way of example only and not by way of limitation, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0046] [Figure 1] FIG. 2 is a rear side perspective view of the nodule mining apparatus of the first embodiment. [Figure 2] FIG. 2 is a front side perspective view of the nodule mining apparatus of FIG. 1. [Figure 3] FIG. 3 is a detailed view of a portion of the nodule mining apparatus of FIG. 2. [Figure 4] 2 is a front view of the device of FIG. 1 with the duct of the collection unit in the deployed state. [Figure 5] FIG. 5 is a side view of the device of FIG. [Figure 6] 2 is a front view of the device of FIG. 1 with the duct of the collection unit in the retracted state. [Figure 7]FIG. 7 is a side view of the device of FIG. 6. [Figure 8] FIG. 2 shows the apparatus of FIG. 1 being lowered to the seabed. [Figure 9] FIG. 2 shows the device of FIG. 1 connected to a riser. [Figure 10] FIG. 2 shows the apparatus of FIG. 1 harvesting nodules. [Figure 11] FIG. 10 is a front view of the device of the second embodiment, with the duct of the collection unit in the deployed state. [Figure 12] FIG. 12 is a side view of the device of FIG. 11. [Figure 13] FIG. 12 is a front view of the device of FIG. 11 with the duct of the collection unit in the retracted position. [Figure 14] FIG. 14 is a side view of the device of FIG. 13. [Figure 15] FIG. 12 is a front perspective view of the sorting device of the apparatus of FIG. 11. [Figure 16] FIG. 16 is a rear perspective view of the sorting device of FIG. 15. [Figure 17] FIG. 16 is a cross-sectional view of the tank of the sorting device of FIG. 15. DETAILED DESCRIPTION OF THE INVENTION

[0047] 1-10, an apparatus embodying the present disclosure for removing nodule material 2 (FIG. 3) from the seabed 4 (FIG. 8) comprises a nodule mining vehicle 6. The nodule mining vehicle 6 has a buoyant member 8 for reducing the weight of the vehicle 6 in the water, first locomotion means in the form of a first propulsion unit 10 for moving the vehicle 6 vertically relative to the seabed 4, and second locomotion means in the form of a second propulsion unit 12 for moving the vehicle 6 horizontally relative to the seabed 4 when not in direct contact with the seabed 4. The vehicle 6 also comprises tracks 14 for moving the vehicle 6 relative to the seabed 4 when the vehicle 6 is in contact with the seabed 4 and for steering the vehicle 6.

[0048] Material removal means in the form of a collection unit 16 is provided forward of the track 14 and has a plurality of inlets 18 for receiving nodule material 2 removed from the seabed 4. The collection unit 16 has screening means in the form of a ramp 20 having a surface 22 inclined relative to the seabed 4 for separating nodule material 2 from non-nodule material, such as sediment, and a second aperture 24 for preventing the passage of nodules 2 while allowing sediment to pass. Seabed engagement means in the form of protrusions in the form of teeth 26 engage the seabed 4 and engage nodules 2 located on the seabed 4 to assist the passage of these nodules 2 into the collection unit 16. The teeth 26 are located forward of the inlets 18 and extend forward of the vehicle 6 in the direction of travel of the vehicle 6. This allows the teeth 26 to engage the nodules 2 in a manner that minimizes disturbance of the seabed 4 while the nodules 2 slide up the ramp 20 and into the inlet 18, thereby minimizing the environmental impact of the nodule collection process.

[0049] The collection unit 16 comprises suction means in the form of eductors 28 connected via respective ducts 30 to the inlets 18 for removing the nodules 2 from the sloping surface 22 of the slope 20. The ducts 30 lead to storage means in the form of tanks 32 having a sloping bottom surface 34 so as to enable the nodules 2 to be collected at the rear of the tank 32 where they are stored, before being pumped to the surface by a dredge pump 36 and a further pump (not shown) on a riser 38 which transports the nodules 2 to the surface. The eductors 28 can reverse the flow of water through the conduits 30 to assist in clearing blockages.

[0050] Additionally, the collection unit 16 includes a first aperture 40 on its rear surface that allows the nodules 2 to pass through these apertures 40 in the event that one or more of the ducts 30 becomes blocked. This prevents each duct 30 from becoming blocked by preventing the nodules 2 from blocking the inlet 18 as the vehicle 6 moves forward.

[0051] The outlet of the dredge pump 36 is connected to a coupling means in the form of a latching mechanism 42 which enables the vehicle 6 to be coupled to the riser 38 so that the nodule material 2 can be pumped from the tank 32 to a vessel located above the waterline. The latching mechanism 42 extends substantially vertically and is pivotally mounted to the vehicle 6 so that the vehicle 6 can easily rotate 180 degrees at the end of its path, thereby allowing for more effective collection of the nodules 2.

[0052] Next, the operation of the vehicle 6 will be described with reference to FIGS.

[0053] First, vehicle 6 is lowered from a surface vessel (not shown) to the seabed 4 by an umbilical cable 44 connected to a suspension point 46. As shown in Figure 8, vehicle 6 is then raised from the seabed 4 by first propeller 10 and second propeller 12 so that a latching mechanism 42 of vehicle 6 can be connected to riser 38. Then, as shown in Figure 10, vehicle 6 returns to the seabed 4 and moves along the seabed 4 by second propeller 12 and / or caterpillar 14 to harvest nodules 2.

[0054] 11-17, in which parts common to the embodiment of FIGS. 1-10 are designated by like reference numerals increased by 100, a second embodiment of a vehicle 106 is shown. The vehicle 106 has a collection unit 116 with separately retractable collection ducts 130 that are movable between a stowed configuration ( FIGS. 13 and 14 ), allowing the vehicle 106 to be more compact as it is being deployed to the seabed, and a deployed configuration ( FIGS. 11 and 12 ), in which the collection unit 116 is at its maximum lateral width. The collection ducts 130 are connected to a conduit 150 ( FIGS. 12 and 14 ), which in turn is connected to an inlet 152 leading to a sorting device comprising a tank 132 for separating nodule material from non-nodule material, such as silt or sediment. The inlet 152 faces a transversely central region of the tank 132.

[0055] The sorting apparatus is shown in further detail in Figure 17. The tank 132 has a body 154 that tapers from an inlet 152 to a first outlet 156 located in the lower portion of the tank 132. The inlet 152 leading into the tank 132 defines nozzles 158 that slow the velocity of water 160 containing nodule and non-nodule material as it enters the tank 132. As a result, the nodules sink to the bottom 134 of the tank 132, while the non-nodule material tends to remain suspended in the water.

[0056] Directing the nodule-laden water towards the transverse centre of the tank 132 in conjunction with the tapered tank body 154 minimises turbulence in the nodule-laden water flow, which in turn minimises obstruction to the settling of the nodules near the first outlet 156. Additionally, the tank 132 includes flow redirection means in the form of a curved upper plate 162 for minimising turbulence in the water flow while redirecting the nodule-laden water flow towards the first outlet 156. The tank 132 also has a sloping lower surface 134 that extends towards the first outlet 156, which causes the nodules to tend to migrate along the lower surface 134 towards the first outlet 156, particularly when the sorting apparatus is vibrating in use.

[0057] The second outlet 164 is located at a higher elevation than the first outlet 156, and a direct path from the inlet 152 to the second outlet 164 is blocked by barrier means in the form of a baffle plate 166 located in the upper part of the tank 132. As a result, when water containing nodule and non-nodule material is pumped into the tank 132, the nodules will have a greater tendency to collect around the first outlet 156, while the non-nodule material, such as silt or sediment, will be able to reach the second outlet 164 by passing under the baffle plate 166, thereby allowing the suspended non-nodule material to reach the second outlet 164, but making it very difficult for the nodules to reach the second outlet 164. In this manner, by appropriate control of the pumping rates of water out of the first outlet 156 and the second outlet 164, the concentration of nodules in the water pumped out of the first outlet 156 is maximized and the concentration of nodules in the water pumped out of the second outlet 164 is minimized. This results in a minimized amount of unwanted non-nodule material being pumped to the surface via the riser 38, thereby reducing the environmental impact of returning such material to the seabed, especially if the amount of such non-nodule material is small enough to allow it to be transported to shore.

[0058] Those skilled in the art will appreciate that the above embodiments have been described solely by way of example and not by way of limitation, and that various changes and modifications may be made thereto without departing from the scope of the present disclosure as defined by the appended claims. [Explanation of symbols]

[0059] 2 nodule material, nodule 4 Undersea 6 Nodule Mining Vehicle 8 Buoyancy member 10 First Propulsion Unit 12 Second Propulsion Unit 14 Caterpillar 16 Collection Units 18 Entrance 20 Slope 22 Sloped surface 24 Second Aperture 26 teeth 28 Inductor 30 Ducts and conduits 32 Tank 34 Sloped bottom surface 36 Dredge Pump 38 Riser 40 First Aperture 42 Latching mechanism 44 Umbilical Cable 46 Suspension Points 106 vehicles 116 Collection Unit 130 Collection duct 132 Tank 134 Bottom, downward slope 150 Conduit 152 Entrance 154 Body, tapered tank body 156 Exit 1 158 nozzles 160 Water containing nodule and non-nodule material 162 Curved upper plate 164 Second Exit 166 Baffle plate

Claims

1. 1. An apparatus for separating nodule material from non-nodule material, comprising: at least one container for receiving a liquid containing nodule material and non-nodule material; at least one respective inlet for allowing a liquid containing nodule material and non-nodule material to enter at least one of said vessels; at least one respective first outlet for allowing liquid to exit at least one said container; at least one respective second outlet for allowing liquid to exit at least one of the containers, wherein the at least one second outlet is located at the same height as the at least one inlet and the at least one first outlet is located at a lower height than the at least one inlet, whereby the at least one second outlet is located at a higher position than the at least one first outlet located on the corresponding container; a barrier means for interrupting a linear path from said at least one inlet to said at least one second outlet, forcing liquid to flow downwardly towards said at least one first outlet; Equipped with said barrier means comprising at least one plate; said barrier means causes liquid to move downwardly from said at least one inlet to said at least one first outlet once and then from said at least one inlet to said at least one second outlet by passing under said barrier means, thereby reducing the velocity of said liquid entering said vessel via said at least one inlet; Device.

2. 10. The apparatus of claim 1, further comprising flow redirection means for redirecting liquid flow toward at least one of said first outlets.

3. The apparatus of claim 2 wherein the flow redirecting means comprises a curved surface.

4. 4. The apparatus of claim 1, wherein at least one of the containers comprises a respective body tapering towards the at least one first outlet.

5. 5. The apparatus of claim 1, wherein at least one of the containers comprises a lower surface that slopes towards the at least one first outlet.

6. 6. The apparatus of claim 4 or 5, wherein the at least one inlet is directed toward a substantially central portion of the container in a direction different from an oblique direction extending from the at least one inlet to the at least one first outlet.

7. 7. The apparatus of claim 1, wherein at least one of the inlets defines a nozzle.

8. 8. The apparatus of claim 1, further comprising pump means for pumping liquid into at least one of the inlets and / or from at least one of the first outlets and / or from at least one of the second outlets.

9. 1. Apparatus for removing nodular material from the bottom of a body of water, comprising: a moving means for moving the device relative to the bottom of the body of water; material removal means for removing nodule material from the bottom of the body of water; connector means adapted to be connected to a conduit to enable transport of the removed nodule material to a vessel on the surface of the body of water; An apparatus for separating nodular from non-nodular material according to any one of claims 1 to 8; An apparatus comprising:

10. 1. Apparatus for removing material from the bottom of a body of water, comprising: a first moving means for moving the apparatus in a substantially vertical direction relative to the bottom of the body of water; second moving means for moving the apparatus substantially horizontally relative to the bottom of the body of water; material removal means for removing material from the bottom of the body of water; connector means adapted to be connected to a conduit to enable transport of said removed material to a vessel on the surface of said body of water; An apparatus for separating nodular from non-nodular material according to any one of claims 1 to 8; An apparatus comprising:

11. 11. The apparatus of claim 10, wherein the first locomotion means comprises at least one propulsion unit.

12. 12. The apparatus of claim 10 or 11, wherein the second locomotion means comprises at least one propulsion device.

13. 13. The apparatus of any one of claims 10 to 12, wherein the second locomotion means comprises a plurality of tracks.

14. 14. Apparatus according to any one of claims 10 to 13, further comprising buoyancy means for reducing the weight of the apparatus in water.

15. 15. Apparatus according to any one of claims 10 to 14, further comprising a containment means for containing the removed material prior to transport to a vessel.

16. 1. Apparatus for removing nodular material from the bottom of a body of water, comprising: a moving means for moving the device relative to the bottom of the body of water; material removal means for removing nodule material from the bottom of the body of water; connector means adapted to be connected to a conduit to enable transport of said removed nodule material to a vessel on the surface of said body of water; Equipped with the material removal means comprises at least one inlet and seabed engagement means for engaging the bottom of the body of water, the seabed engagement means being arranged forward of the at least one inlet in a direction of movement of the apparatus and comprising a plurality of protrusions adapted to extend substantially in the direction of movement of the apparatus; further comprising at least one first aperture positioned rearward of the at least one inlet in a direction of movement of the device to allow passage of nodular material; further comprising a separating means disposed adjacent to at least one of said inlets for separating nodule material from non-nodule material on the bottom of said body of water; the sorting means comprises a plate-like member which, in use, is inclined relative to the bottom of the body of water and has at least one surface having at least one second aperture for passing non-nodule material and preventing the passage of nodule material; the sorting means is provided on the seabed engaging means so as to cover at least a portion of the seabed engaging means; The selecting means is smoothly and continuously connected to the first aperture. Device.

17. The device of claim 16 , wherein the protrusion comprises a plurality of teeth.

18. 18. Apparatus according to claim 16 or 17, further comprising suction means for removing nodular material from at least one of said inlets.

19. 19. The apparatus of claim 18, wherein the suction means is adapted to reverse the direction of water flow passing through the suction means.

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