Water current ore lifting system

Abstract

To provide a piston pump capable of surely switching an oscillation pipe to a communication position with right and left spectacle plate suction / discharge ports by reducing a force for oscillating the oscillation plate even in the case of high-pressure pumping, and a water flow lifting system with the same.SOLUTION: In a piston pump 1 with a backflow prevention mechanism, for a pair of left and right suction / discharge ports 1L and 1R provided in a spectacle plate 8, a mutual interval is set to be equal to or more than an opening width of the suction / discharge ports 1L and 1R. In a wear plate 12, in a slide contact part between the wear plate 12 and the spectacle plate 8, seal parts 14L and 14R having a width equal to or more than the opening width of the pair of suction / discharge ports 1L and 1R are provided at both sides of its own opening 13. The wear plate 12 is then supported by a fluid bearing 80 which receives a thrust load applied to the wear plate 12 when switching a connection state of an oscillation pipe 2 with a pair of pump cylinders 4L and 4R.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a technique for lifting marine resources, such as those present in seafloor hydrothermal deposits, from the seabed. [Background technology]

[0002] In recent years, the prices of useful metals, which are indispensable for manufacturing various industrial equipment but are in small quantities, have been soaring. Useful metals are indispensable for industry. However, not only are the recoverable amounts small, but there are also geopolitical risks because the number of producing countries is limited. Therefore, among minerals containing useful metals, marine resources found in seafloor hydrothermal deposits have been attracting attention. A pump lift system using an ore-lifting pump has been attempted as a method for lifting marine resources from seafloor hydrothermal deposits, etc. So far, mining equipment has been proposed for this type of deposit in which ore is crushed in the sea by a mining machine equipped with an excavation head such as a drum cutter or a cutter head, the crushed ore gravel is made into slurry in the sea, and the slurry is transported to the ore-lifting pump (for example, see Non-Patent Document 1).

[0003] On the other hand, oscillating pipe type piston pumps are used as a pumping technology for pumping low-slump concrete, which has poor fluidity, in architectural and civil engineering works, and for pumping gravel and soil in earth pressure shield construction methods. In a piston pump using a oscillating tube, due to the structure that uses a oscillating tube to switch between discharge and suction, when switching between discharge and suction, a moment occurs when the discharge side and suction side become connected in the middle of switching the position of the communication port of the oscillating tube from the discharge and suction port on one side to the discharge and suction port on the other side. At this time, part of the transported object flows back instantaneously from the high-pressure discharge side pump cylinder to the low-pressure suction side pump cylinder. When such a backflow occurs, the volumetric efficiency decreases, and there is a risk of vibration or shock occurring.

[0004] In response to this, a piston pump of a oscillating pipe type having a backflow prevention mechanism has been proposed. For example, in the piston pump described in Patent Document 1, the distance between the left and right suction and discharge ports of the spectacle plate is set to be equal to or greater than the opening width of the communication port of the oscillating pipe. In the technology described in the same document, a wear plate is provided having seal portions located on both sides of the communication port, and the seal portions on both sides are formed to be wider than the opening width of a pair of suction and discharge ports. A guide plate is provided on the back of the wear plate to slidably clamp the wear plate against the opposing spectacle plate when the oscillating tube is switched. Furthermore, for example, the piston pump with a backflow prevention mechanism described in Patent Document 2 has lubrication grooves for supplying lubricant to the sliding surfaces of the wear plate relative to the spectacle plate and the guide plate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2002-213348 A [Patent Document 2] JP 2003-343429 A [Non-patent literature]

[0006] [Non-Patent Document 1] Submarine Hydrothermal Deposit Development Project First Phase Final Evaluation Report (Japan Oil, Gas and Metals National Corporation) Summary of the Invention [Problem to be solved by the invention]

[0007] Multi-stage centrifugal pumps are used as ore-lifting pumps to transport ores from seafloor hydrothermal deposits. Multi-stage centrifugal pumps have a complex liquid-contacting part shape with multiple impellers and multiple volute chambers, and super duplex stainless steel, high chromium cast iron, etc. are used for the liquid-contacting parts.

[0008] However, when transporting slurry on land using a centrifugal pump, if the wetted parts wear out, it is possible to replace the wetted parts on site, but when transporting slurry from the deep sea using a multi-stage centrifugal pump where marine resources such as seafloor hydrothermal deposits exist, if the wetted parts need to be replaced, the multi-stage centrifugal pump must be pulled up from the deep sea onto a ship to perform the part replacement work. For this reason, when operating at a commercial level, it is thought that if the liquid-contacting parts of a multi-stage centrifugal pump, which has a complex liquid-contacting shape, wear out prematurely, it will be necessary to spend a lot of time and money to replace them.

[0009] It is also possible to adopt a piston pump of a swaying pipe type having a backflow prevention mechanism in the technology for extracting ore from seafloor hydrothermal deposits. However, in both of the technologies described in Patent Documents 1 and 2, when the communication position of the swaying pipe is switched, the spectacle plate and the wear plate slide against each other by surface contact, and the guide plate and the wear plate also slide against each other by surface contact. As a result, there is a large sliding resistance when the oscillating tube moves to switch its communication position, and a large driving force is required to connect the oscillating tube to the suction and discharge ports of the left and right eyeglass plates, resulting in the problem of each component and driving device becoming larger.

[0010] In addition, piston pumps equipped with this type of backflow prevention mechanism are used to pump materials such as low-slump concrete and soil and sand with poor fluidity in construction and civil engineering works, or dewatered sludge with low moisture content generated in sewage treatment plants and sewage treatment plants. Therefore, the higher the pressure of the transported material, the stronger the pressure of the wear plate is pushed by the material when the oscillating tube is switched, which causes a gap to form between the spectacle plate and the wear plate, resulting in a large leakage of the material.

[0011] Therefore, the present invention has been made with attention to such problems, and its objective is to provide a piston pump and a water flow ore lifting system equipped with the same that can reduce the force that oscillates the oscillating pipe, even during high-pressure pumping, and can reliably switch the oscillating pipe to a communicating position with the suction and discharge ports of the left and right spectacle plates. [Means for solving the problem]

[0012] In order to solve the above problems, a piston pump according to one aspect of the present invention comprises a hopper having a transport pipe for transporting an object to be transported connected to its front wall side, a spectacle plate provided on the rear wall side of the hopper and having a pair of left and right suction and discharge ports with the distance between the pair of suction and discharge ports set to be equal to or greater than the opening width of the suction and discharge ports, a swinging pipe housed in the hopper so as to be swingable and movable so as to alternately switch an opening at its tip to a position facing one of the pair of suction and discharge ports so as to alternately connect the transport pipe to the pair of suction and discharge ports, an actuator that swings the swinging pipe to a position alternately connected to the pair of suction and discharge ports, and an actuator that is connected to the rear portions of the pair of suction and discharge ports and that moves the swinging pipe away from the hopper when not in communication with the swinging pipe. the pair of left and right pump cylinders that suck up the object to be transported in a pump and discharge the sucked up object to be transported when connected to the oscillating pipe; a wear plate that is fitted to the outer peripheral surface of the tip of the oscillating pipe so as to be slidable relatively to the outer peripheral surface of the tip in a direction along the oscillation axis and is attached so as to be in sliding contact with the opposing surface of the spectacle plate, and has seal portions on both left and right sides of the opening of the tip of the oscillating pipe where the wear plate slides against the opposing surfaces of the spectacle plate, with a width greater than or equal to the opening width of the pair of suction and discharge ports of the spectacle plate; and a fluid bearing that receives the thrust load applied to the wear plate when the connection state between the oscillating pipe and the pair of pump cylinders is switched.

[0013] In addition, in order to solve the above-mentioned problems, a water flow ore pumping system according to one embodiment of the present invention is a water flow ore pumping system that transports marine resources present in seafloor hydrothermal deposits, etc. by injecting them into a water flow, and is characterized in that it comprises a circulation pipeline having an outward water flow pipe and a return water flow pipe and configured to form a water flow from the outward water flow pipe to the return water flow pipe, a high-pressure pump installed so as to be able to inject high-pressure water into the outward water flow pipe, a piston pump installed so as to be able to inject the marine resources into the circulation pipeline, and a recovery hopper installed so as to be able to recover the marine resources from the return water flow pipe, and is characterized in that the piston pump is equipped with a piston pump according to one embodiment of the present invention.

[0014] In a piston pump according to one aspect of the present invention, the thrust load acting on the wear plate when the connection state between the oscillating tube and the left and right pumping cylinders is switched relative to the support portion of the wear plate is supported by a fluid bearing. As a result, in the piston pump according to one aspect of the present invention, the thrust load applied to the wear plate from the pump cylinder side toward the oscillating tube can be offset and reduced by the thrust force from the oscillating tube side toward the pump cylinder due to the water pressure applied to the water pressure supply surface of the fluid bearing. In addition, the fluid bearing, which receives the thrust load from the wear plate, slides without contact with the wear plate due to the water film on the pressure-receiving surface. This significantly reduces the coefficient of friction, and therefore the driving force required to connect the oscillating pipe to the left and right suction and discharge ports of the spectacle plate.

[0015] Furthermore, according to one embodiment of the water current ore lifting system of the present invention, a circulating water current can be created between the ship and the vicinity of the seabed using high-pressure water pumped from a high-pressure pump installed on board, and marine resources such as ore can be injected and lifted using a piston pump of one embodiment of the present invention placed on or near the seabed, making it possible to lift ore from the deep sea to the ship with an extremely simple configuration. In the water current pumping system according to one aspect of the present invention, it is preferable to have a supply pipeline which branches off the high pressure water supplied by the high pressure pump from the circulation pipeline and supplies the high pressure water to the hydrodynamic bearing. It is also preferable that the supply pipeline is branched off from the circulation pipeline at a position upstream of a position where the drilled material is injected into the circulation pipeline by the piston pump.

[0016] With this configuration, for example, high-pressure water supplied by a high-pressure pump installed on a ship can be branched off from the circulation pipeline and supplied to the fluid bearing, so that the high-pressure water can be supplied by the high-pressure pump installed on the ship, eliminating the need to install a pump on the seabed to supply high-pressure water to the fluid bearing. Effect of the Invention

[0017] As described above, according to the present invention, even during high pressure pumping, the force for swinging the swing tube can be reduced, and the swing tube can be reliably switched to the position communicating with the suction and discharge ports of the left and right eyeglass plates. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic overall configuration diagram showing one embodiment of a water current ore lifting system according to one aspect of the present invention. FIG. [Diagram 2] 2 is a vertical cross-sectional view showing an embodiment of a connection state between the piston pump shown in FIG. 1 and a circulation pipe. FIG. [Diagram 3] 3 is a schematic explanatory view showing a connection state between the piston pump and a circulation pipe shown in FIG. 2, as viewed from the pump cylinder side. FIG. [Figure 4] 3A, 3B, and 3C are explanatory diagrams of the operating state of the backflow prevention mechanism in the piston pump shown in FIG. 2, and show an image of the operation as viewed from the XX cross section of FIG. 2. [Diagram 5] 3A to 3K are explanatory diagrams showing the operation state of the backflow prevention mechanism as viewed from the pump cylinder side in the piston pump shown in Fig. 2. In the diagram, the shaded portion in the flow path shows the transition of the communication state. [Figure 6] 4 is a timing chart showing the operating state of ON / OFF control of a plurality of solenoid valves. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the drawings are schematic. Therefore, it should be noted that the relationship between thickness and planar dimensions, ratios, etc. are different from the actual ones, and the drawings also include parts where the relationship and ratio of dimensions differ from each other. Furthermore, the embodiments described below are merely examples of devices and methods for embodying the technical ideas of the present invention, and the technical ideas of the present invention do not limit the materials, shapes, structures, arrangements, etc. of the components to the embodiments described below.

[0020] First, a water current ore lifting system and a water current ore lifting method using the same according to a first embodiment will be described. As shown in Figure 1, this embodiment is a water current ore lifting method in which a seafloor hydrothermal deposit T on the seafloor SB is excavated using a mining machine (not shown), and the excavated ore, which is a marine resource, is lifted to an offshore base G of an offshore SL by a water current ore lifting system 300 according to the present invention. As shown in the figure, the water flow ore lifting system 300 includes ore lifting equipment 200 suspended from an offshore base G to the seabed SB, and a circulation pipeline 310. The ore lifting equipment 200 is equipped with a piston pump 1 with a backflow prevention mechanism. The circulation pipeline 310 includes an outward water flow pipe 311 extending to the vicinity of the seabed SB, and a return water flow pipe 312 extending from the vicinity of the seabed SB to the offshore base G.

[0021] The offshore base G is, for example, a ship, and a high-pressure pump 320 is installed on the offshore base G. In the water flow ore lifting system 300 of this embodiment, the high-pressure pump 320 injects high-pressure water into the outward water flow pipe 311, and a circulating flow is formed in which the water flow from the offshore base G to the seabed SB through the outward water flow pipe 311 is returned to the offshore base G again through the return water flow pipe 312. Furthermore, the water flow ore lifting system 300 of this embodiment is configured to inject the excavated ore into the return water flow pipe 312 using a piston pump 1 equipped with a backflow prevention mechanism, and transport the ore to the offshore base G by entraining it in the water flow of the circulation pipeline 310.

[0022] More specifically, as shown in the figure, the water flow ore lifting system 300 of this embodiment includes an ore lifting device 200 equipped with one piston pump 1, a circulation pipeline 310 having an outward water flow pipe 311 and a return water flow pipe 312, a high-pressure pump 320 installed at the offshore base G, and a recovery hopper 330 installed at the offshore base G. The recovery hopper 330 is installed so as to be able to recover marine resources (in this example, ore excavated on the seabed using mining equipment) from the return water flow pipe 312.

[0023] A crane 370 is installed at the offshore base G, and the crane 370 can supply the electric power and pressurized oil required for driving the ore lifting equipment 200 and send and receive signals via an umbilical cable 360. A classifier (not shown) is attached to the recovery hopper 330 installed at the offshore base G, and the classifier separates the ore components from the seawater and discharges only the seawater into a tank 340. The high-pressure pump 320 is installed so as to be able to inject the seawater stored in the tank 340 into the outward water flow pipe 311 as high-pressure water.

[0024] The circulation pipeline 310 is piped from the offshore base G to the ore lifting equipment 200 installed near the seafloor hydrothermal deposit T on the seabed SB so as to form a circulating water flow from the outward water flow pipe 311 to the return water flow pipe 312. The piston pump 1 is installed in the ore lifting equipment 200 so as to be able to inject marine resources into the circulation pipeline 310. The laying range of the forward water flow pipe 311 and the return water flow pipe 312 can be set as appropriate. In this embodiment, the forward water flow pipe 311 is located upstream of the U-shaped turn back portion near the ore lifting equipment 200, and the return water flow pipe 312 is located downstream of the U-shaped turn back portion. The piston pump 1 is installed in the housing 210 of the ore lifting equipment 200 so that the marine resource can be injected into the return water flow pipe 312 via the discharge piping 6.

[0025] In the ore lifting equipment 200 of this embodiment, an input hopper 211 is provided on the upper part of a housing 210 into which ore excavated by mining equipment (not shown) is input, and an excavation device 212 is attached to the discharge outlet at the lower part of the input hopper 211. A screw conveyor 225 is disposed at the upper interior portion of the housing 210, and the ore excavated by an excavation device 212 such as a belt feeder is introduced into the screw conveyor 225. The front end portion (outlet) of the screw conveyor 225 passes through the rear portion of the hopper 9 of the piston pump 1 and communicates with the inside of the hopper 9, and the ore can be delivered toward the hopper 9 at a predetermined amount at a time by driving the screw conveyor 225.

[0026] 2, the piston pump 1 of this embodiment includes a hopper 9 that opens at the top, and a swinging tube 2 that is bent into a substantially S-shape is swingably housed inside the hopper 9. A base end portion 2b of the swinging tube 2 in the hopper 9 is rotatably supported at a lower position of the front wall 1f of the hopper 9. A coupling 5 is provided at the base end 2b of the oscillating pipe 2, which is connected to a discharge pipe 6 leading to the return water flow pipe 312 shown in Fig. 1. One end of the discharge pipe 6 is connected to the coupling 5, and the base end 2b of the oscillating pipe 2 is disposed so as to communicate with the discharge pipe 6.

[0027] One end of a swing pipe shaft 10 with a horizontal axis is fixed to the upper part of the intermediate part 2m of the swing pipe 2. One end of the swing pipe shaft 10 is rotatably supported on the rear wall 1b of the hopper 9. The other end of the swing pipe shaft 10 extends outside the rear wall 1b of the hopper 9, and a switching lever 11 is fixedly attached to it. A rotation center CL1 of the swing pipe shaft 10 and a rotation center CL2 of the base end part 2b of the swing pipe 2 are on one horizontal swing axis CL. A gap plate 8 having a pair of suction and discharge ports 1L, 1R on the left and right sides is provided at the bottom of the back wall 1b of the hopper 9. The gap plate 8 is disposed at a portion where the tip 2t of the oscillating tube 2 makes sliding contact. The gap plate 8 is attached from the back side of the hopper 9 so as to be replaceable. The tip 2t of the oscillation tube 2 slides while being pressed against the spectacle plate 8. For this reason, a replaceable wear plate 12 is attached to the tip 2t of the oscillation tube 2. In this embodiment, the spectacle plate 8 and the wear plate 12 are made of a wear-resistant material.

[0028] In the piston pump 1 of this embodiment, a wear ring 20 that comes into sliding contact with the spectacle plate 8 is attached to the wear plate 12. In the wear plate 12 of this embodiment, a cylindrical wear ring 20 is attached to the tip 2t of the oscillating tube 2 at a position coaxial with the central opening 13 of the wear plate 12. A pair of pump cylinders 4L, 4R, each with one open end, are attached to the back of the hopper 9, facing a pair of suction and discharge ports 1L, 1R of the spectacle plate 8, with their axes parallel to the oscillation axis CL.

[0029] The pair of pump cylinders 4L, 4R each have a conveying piston 7 therein. Each conveying piston 7 is hydraulically driven to reciprocate alternately by a pair of drive cylinders 15L, 15R shown in FIG. As a result, each pump cylinder 4L, 4R is driven to suck in marine resources in the hopper 9 when the corresponding suction and discharge port 1L, 1R is not connected to the oscillating pipe 2, and to discharge the sucked in marine resources toward the return water flow pipe 312 when connected to the oscillating pipe 2.

[0030] As shown in Fig. 3, a pair of switching cylinders 3L, 3R are attached as actuators between the switching lever 11 and the hopper 9. The pair of switching cylinders 3L, 3R are configured such that when one of the switching cylinders 3L, 3R extends, the other contracts. In response to the extension and contraction of the pair of switching cylinders 3L, 3R, the swing pipe shaft 10 rotates around the swing axis CL at a predetermined timing, and the swing pipe 2 swings left and right within a predetermined rotation range. As a result, the tip 2t of the swing pipe 2 shown in Fig. 2 alternately moves to a position facing either the left or right suction and discharge ports 1L, 1R.

[0031] Here, the piston pump 1 of the present embodiment is provided with a backflow prevention mechanism. In the backflow prevention mechanism of this embodiment, as shown in Figure 5 (b), the distance between the left and right suction and discharge ports 1L, 1R of the spectacle plate 8 is greater than or equal to the width of the opening 20m of the wear ring 20 that rotates integrally with the wear plate 12. 5, the wear plate 12 has seal portions 14L, 14R at both left and right ends of the opening 13 (see FIG. 4) of the wear plate 12. The left and right seal portions 14L, 14R are provided so as to rotate while being in sliding contact with the surfaces facing the spectacle plate 8. The seal portions 14L, 14R in this embodiment are provided with a width equal to or larger than the opening width of the pair of suction and discharge ports 1L, 1R formed in the spectacle plate 8 in the rotation direction of the oscillating tube 2. In this embodiment, the opening shapes of the pair of suction and discharge ports 1L, 1R are circular, and the opening diameters of the pair of suction and discharge ports 1L, 1R are the same.

[0032] 2, the inner periphery of wear plate 12 is supported by passive body 61A and rolling elements 62A attached to race 60A fixed to the hopper 9 side, and is further supported by passive body 61B and rolling elements 62B attached to race 60B fixed to the set plate 40 side. The outer periphery of wear plate 12 is supported from the front and rear by fluid bearing 80 fixed to the hopper 9 side, and passive body 61C and rolling elements 62C attached to race 60C fixed to the set plate 40 side.

[0033] In this embodiment, cylindrical rollers are used for the rolling elements 62A, 62B, and 62C, and the races 60A, 60B, and 60C are cages that rotatably hold the rolling elements 62A, 62B, and 62C. A plurality of passive bodies 61A, 61B, and 61C having concave cylindrical surfaces corresponding to the rolling elements 62A, 62B, and 62C are interposed on the side opposite the wear plate 12 for the rolling elements 62A, 62B, and 62C, and the passive bodies 61A, 61B, and 61C hold the position and orientation of the rolling elements 62A, 62B, and 62C in the direction along the oscillation axis CL.

[0034] Here, the fluid bearing 80 of this embodiment has a bearing frame 80h formed in a substantially bow-like shape, a plurality of first sliding pieces 80s, and a plurality of second sliding pieces 80p. Both ends of the bearing frame 80h are fixed to the inner surface of the lower side of the hopper 9 by screws or the like. A plurality of accommodation holes for accommodating the first sliding piece 80s or the second sliding piece 80p are formed through the bearing frame 80h along the circumferential direction. Each of the first sliding piece 80s and each of the second sliding pieces 80p are formed in a substantially fan shape along the circumferential direction. Furthermore, a set of a plurality of first sliding pieces 80s and a plurality of second sliding pieces 80p, which are accommodated in a plurality of accommodation holes of the bearing frame 80h, are arranged along the circumferential direction to form the entire fluid bearing that supports the outer periphery of the wear plate 12.

[0035] Each second sliding piece 80p is formed to have a circumferential length longer than that of the first sliding piece 80s. A high-pressure water inlet passage is formed in each second sliding piece 80p so as to communicate from the outer circumferential surface to the center, and a high-pressure water outlet is formed through the high-pressure water inlet passage on the surface facing the outer circumferential surface of the wear plate 12 when each second sliding piece 80p is attached, forming a high-pressure water supply surface. Furthermore, in the water current ore lifting system 300 of this embodiment, a supply pipeline 350 is provided branching off from the circulation pipeline 310. The supply pipeline 350 is provided upstream of the circulation pipeline 310 relative to the connection portion of the discharge pipe 6. The supply pipeline 350 makes it possible to branch the high-pressure water supplied from the high-pressure pump 320 shown in FIG. 1 to the circulation pipeline 310 and supply the high-pressure water to the hydrodynamic bearing 80.

[0036] FIG. 5 shows an image of the swinging action of the backflow prevention mechanism as viewed from the pump cylinders 4L and 4R. During the swing stroke shown in (a) to (f) of the same figure, a load is applied to the left side of the wear plate 12 in the same figure from the pump cylinders 4L, 4R side toward the swing tube 2, with the thrust load changing and increasing. On the other hand, during the swing stroke shown in (g) to (k) of the same figure, a load is applied to the right side of the wear plate 12 in the same figure from the pump cylinders 4L, 4R side toward the swing tube 2, while the thrust load changes and decreases.

[0037] In the water current ore lifting system 300 of this embodiment, in each of the swinging strokes (a) to (k) that transition in this manner, in order to respond as much as possible to the thrust load acting on the wear plate 12 as the position at which the load is applied and the magnitude of the load change during each swinging stroke, a pressurized transition mechanism 90 is provided that applies the necessary water pressure at the appropriate timing to each second sliding piece 80p of the fluid bearing 80 that supports the outer peripheral side of the wear plate 12.

[0038] As shown in FIG. 2, the pressurization transition mechanism 90 is interposed in the supply pipeline 350. The high-pressure water supplied to the supply pipeline 350 has its pressure adjusted via the pressurization transition mechanism 90, and is supplied from the multiple branch pipelines 351, 352 to each of the second sliding pieces 80p arranged in each portion of the fluid bearing 80 while the pressurization is transitioned. 3, the pressurization transition mechanism 90 has a plurality of branch pipes 351-353, and has a plurality of solenoid valves 91-95, a plurality of throttle valves 96-98, and a plurality of check valves 99a, 99b, which are provided in the branch pipes 351-353. In this embodiment, the supply pipe 350 is branched into three first-stage branch pipes 351, 352, and 353 on the downstream side.

[0039] In the first-stage branch pipe 351 in the center of the figure, a solenoid valve 91 and a throttle valve 96 are interposed from the upstream side, and the downstream side of the throttle valve 96 is further branched into two second-stage branch pipes 351a and 351b. Check valves 99a and 99b are interposed in the second-stage branch pipes 351a and 351b, respectively. The check valves 99a and 99b are oriented to permit flow from the upstream side to the downstream side and to block flow in the opposite direction. In the first-stage branch pipe 352 on the left side of the figure, solenoid valves 92 and 93, and a throttle valve 97 are interposed from the upstream side, and the downstream side of the throttle valve 97 is further branched into three second-stage branch pipes 352a, 352b, and 352c. The branch pipe 351a merges with the branch pipe 352 at the position of the branch pipe 352b. In the first-stage branch pipe 353 on the right side of the figure, solenoid valves 94 and 95, and a throttle valve 98 are interposed from the upstream side, and the downstream side of the throttle valve 98 is further branched into three second-stage branch pipes 353a, 353b, and 353c. Branch pipe 351b merges with branch pipe 353 at branch pipe 353b.

[0040] In the pressurization transition mechanism 90 of this embodiment, an end of the supply pipe 350 branches into six branch pipes 352a, 352b, 352c, and the branch pipes 352a, 352b, 352c are respectively connected to a plurality of branch pipe connection parts provided on the lower surface 9d of the hopper 9. The plurality of branch pipe connection parts have through passages penetrating the thick portion on the lower surface 9d side of the hopper 9, and each through passage opens at a position communicating with the high-pressure water introduction passage on the outer circumferential surface of each of the second sliding pieces 80p described above.

[0041] 6 is a timing chart showing the ON / OFF control operation states of the above-mentioned solenoid valves 91 to 95. As shown in the figure, solenoid valve 91 controls the water pressure so that low-pressure water is injected over the entire operating range of wear plate 12. Here, the time required to switch the connection state between the oscillating tube 2 and the left and right pump cylinders 4L, 4R is short, about 1 to 1.5 seconds. Therefore, in this embodiment, for the injection of high-pressure water into the fluid bearing 80, two solenoid valves 92, 93 and solenoid valves 94, 95 are provided on the left and right, respectively, and the timing of water injection is controlled by the cooperative operation of these.

[0042] 6, in this embodiment, high-pressure water is supplied to each second sliding piece 80p on the left side of the fluid bearing 80 in a portion where the open states of the solenoid valves 92 and 93 overlap. Also, high-pressure water is supplied to each second sliding piece 80p on the right side of the fluid bearing 80 in a portion where the open states of the solenoid valves 94 and 95 overlap. Furthermore, in this embodiment, in order to supply lubricating fluid at an appropriate pressure to the sliding surfaces of each of the first sliding pieces 80s and each of the second sliding pieces 80p of the fluid bearing 80, a solenoid valve 91 and a throttle valve 96 are installed in the central branch pipe 351 from the supply pipe 350, and low-pressure water is supplied to the fluid bearing 80 by the solenoid valve 91 and the throttle valve 96 throughout the entire range of oscillation strokes (a) to (k) shown in Figure 5.

[0043] In addition, in the branch pipeline 352, the solenoid valve 92, the solenoid valve 93 and the throttle valve 97 are arranged to control the high-pressure water to the left side of the wear plate 12, and the high-pressure water that is maximum during the swing strokes (d) to (e) shown in Figure 5 is supplied to the sliding surfaces of each second sliding piece 80p of the fluid bearing 80. In addition, in the branch pipeline 353, the solenoid valve 94, the solenoid valve 95 and the throttle valve 98 are arranged to control the high-pressure water to the right side of the wear plate 12, and the high-pressure water that is maximum during the swing strokes (g) to (h) shown in Figure 5 is supplied to the sliding surfaces of each second sliding piece 80p of the fluid bearing 80.

[0044] As an example of the pressure of the low pressure water and high pressure water supplied to each first sliding piece 80s and each second sliding piece 80p of the fluid bearing 80, the water pressure of the circulation pipe 310 is 7 MPa, while the water pressure of the low pressure water from the central branch pipe 351 is adjusted to 2 MPa by solenoid valve 91 and throttle valve 96 before being supplied to the fluid bearing 80. Also, the water pressure of the high pressure water in branch pipes 352 and 353 is adjusted to 6 MPa by throttle valves 97 and 98, respectively, before being supplied to the fluid bearing 80.

[0045] Next, the effects of this embodiment will be described. According to the water current ore lifting system 300 of this embodiment, high-pressure water is pumped from a high-pressure pump 320 installed on board the ship to create a circulating water current between the ship and the vicinity of the seabed, and a piston pump 1 with a backflow prevention mechanism located near the seabed is used to inject and lift the ore, making it possible to lift ore from the deep sea to the ship with an extremely simple configuration. In particular, according to the piston pump 1 of this embodiment, the support portion of the wear plate 12 has a basic structure in which the wear plate 12 is constantly supported from the front and rear of the oscillation axis via a plurality of rolling bodies 62A, 62B, 62C throughout the entire oscillation range of the oscillating tube 2, and further, when the connection state between the oscillating tube 2 of the oscillating tube type piston pump 1 having a backflow prevention function and the left and right pump cylinders 4L, 4R is switched, the thrust load applied to the wear plate 12 is supported by the fluid bearing 80.

[0046] As a result, the thrust load applied to the wear plate 12 from the pump cylinders 4L, 4R in the direction of the oscillating tube 2 can be offset and reduced by the thrust in the direction of the pump cylinders 4L, 4R from the oscillating tube 2 side due to the water pressure applied to the water pressure supply surface of the fluid bearing 80. In addition, the fluid bearing 80, which receives the thrust load on the wear plate 12, slides in a non-contact manner with the wear plate 12 due to the water film on the pressure-receiving surface, and therefore the friction coefficient can be significantly reduced. As a result, the driving force required to connect the oscillating tube 2 to the suction and discharge ports of the left and right spectacle plates 8 can be reduced.

[0047] Furthermore, the water current ore lifting system 300 of this embodiment has a supply pipeline 350 that branches off high-pressure water supplied from the circulation pipeline 310 by the high-pressure pump 320 and supplies the high-pressure water to the fluid bearing 80, so that the water current ore lifting system 300 of this embodiment can supply high-pressure water to the fluid bearing 80 by branching off the high-pressure water supplied by the high-pressure pump 320 installed on the ship. In other words, the high-pressure water to be supplied to the fluid bearing 80 can be supplied by the high-pressure pump 320 installed on the ship. Therefore, because the high-pressure water is supplied by branching off from the circulation pipeline 310, it is not necessary to provide a pump on the seabed for supplying high-pressure water to the fluid bearing 80.

[0048] As described above, according to the piston pump 1 with backflow prevention mechanism of this embodiment, even during high pressure pumping, the force for swinging the swing pipe 2 can be reduced, and the swing pipe 2 can be reliably switched to the communication positions with the suction and discharge ports 1L, 1R of the left and right spectacle plates 8. And, according to the water current ore lifting system 300 of this embodiment, it is possible to provide a water current ore lifting system 300 capable of lifting ore from the deep sea to the ship with a simple configuration. It should be noted that the water current mineral lifting system 300 according to the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0049] 1 Piston pump 1L, 1R suction and discharge ports 1b Back wall 1f front wall 2. Swing tube 2b Proximal end 2m middle part 2t tip 3L, 3R switching cylinder 4L, 4R pump cylinder 5 Coupling 6 Discharge piping 7 Conveying piston 8 Glasses Plate 9 Hopper 10 Swinging tube shaft 11 Switching lever 12 Wear Plate 13 Opening 14L, 14R seal part 15L, 15R drive cylinder 20. Wearing 20m opening 40 Set Plates 60A, 60B, 60C washer 61A, 61B, 61C Passive 62A, 62B, 62C rolling elements 80 Fluid bearing 90 Pressurized Transition Mechanism 91~95 Solenoid valves 96~98 Throttle valve 99a, 99b Check valve 200 Ore lifting equipment 210 Cabinet 211 Input hopper 212 Cutting device 225 Screw Conveyor 300 Water flow mine lifting system 310 Circulation pipeline 311 Outflow water pipe 312 Return water flow pipe 320 High Pressure Pump 330 Collection Hopper 340 Tank 350 Supply pipeline 351~353 Branch Pipe 352a, 352b, 352c Second stage branch pipe 353a, 353b, 353c Second stage branch pipe 360 Umbilical Cable 370 Crane CL Swing axis G. Offshore Base SB Undersea SL Offshore T Submarine hydrothermal deposits

Claims

1. A water current ore lifting system for injecting and transporting marine resources present in seafloor hydrothermal deposits, etc., into a water current, comprising: A circulation pipe having an outward water flow pipe and a return water flow pipe and configured to form a water flow from the outward water flow pipe to the return water flow pipe; A high-pressure pump installed so as to be able to inject high-pressure water into the outward water flow pipe; A piston pump that is installed so as to be able to inject excavated material into the circulation pipeline; A recovery hopper is provided so that the excavated material can be recovered from the return water flow pipe; The piston pump comprises: a hopper having a transport pipe for transporting an object to be transported connected to a front wall side of the hopper; a spectacle plate provided on a rear wall side of the hopper, having a pair of left and right suction and discharge ports, the distance between the pair of suction and discharge ports being set to be equal to or greater than the opening width of the suction and discharge ports; a swinging tube that is swingably accommodated in the hopper and that is capable of switching and moving an opening at its tip end to a position facing either one of the pair of suction and discharge ports so as to alternately connect the transport tube to the pair of suction and discharge ports; an actuator that swings the swing pipe to a position where the swing pipe alternately communicates with the pair of suction and discharge ports; a pair of left and right pump cylinders respectively connected to rear portions of the pair of suction and discharge ports, which suck up the object to be transported in the hopper when not in communication with the swing pipe, and discharge the sucked up object to be transported when in communication with the swing pipe; a wear plate that is fitted to the outer peripheral surface of the tip of the swing tube so as to be slidable relative to the outer peripheral surface of the tip of the swing tube in a direction along the swing axis and that is attached so as to be in sliding contact with the opposing surface of the spectacle plate, and that has seal portions provided on both left and right sides of the opening at the tip of the swing tube, at the portions where the wear plate and the opposing surfaces of the spectacle plate are in sliding contact with each other, and that are wider than the opening width of the pair of suction and discharge ports of the spectacle plate; a fluid bearing that receives a thrust load applied to the wear plate when a connection state between the swing pipe and the pair of pump cylinders is switched, A water-flow ore-lifting system comprising a supply pipeline which branches off high-pressure water supplied by the high-pressure pump from the circulation pipeline and supplies the high-pressure water to the fluid bearing.

2. 2. The water current ore lifting system according to claim 1, wherein the supply pipeline is branched off from the circulation pipeline at a position upstream of a position where the piston pump injects the excavated material into the circulation pipeline.

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