JP2025004447A - Underwater sediment recovery system and underwater sediment recovery method - Google Patents

Abstract

To provide an underwater sediment recovery system and an underwater sediment recovery method capable of preventing a hose from interfering with the movement of a robot and reducing the load imposed when the robot moves while pulling the hose.SOLUTION: An underwater sediment recovery system of the present invention is configured as an underwater sediment recovery system 100a that recovers and accumulates sediment from a flooded floor and includes a robot 100 that travels across the flooded floor to suck up the sediment, a discharge nozzle 156 positioned on top of the robot to discharge the sucked up sediment to an outside, and a transport boat 200 that can travel on the water surface of the floor. The transport boat 200 has a bucket 210 with an openable and closable bottom, a float 220 that floats the bucket on the water surface, and a screw 230 that moves the bucket. The discharge nozzle 156 is installed in a position where it can discharge sediment into the bucket of the transport boat adjacent to the robot.SELECTED DRAWING: Figure 2

Description

The present invention relates to an underwater sediment recovery system that recovers and accumulates sediment from flooded floors, and an underwater sediment recovery method using the same.

Conventionally, sediments that have settled in water have been collected to prevent water pollution and to remove harmful substances that have settled in the water. For example, Patent Document 1 discloses a sludge collection device and method as a means for collecting sediments. The sludge collection device in Patent Document 1 has a dredging device that is movable underwater and can suck up and collect sludge from the bottom of the water, a treatment device that is movable underwater and stores the collected material in a collected material receiving tank after removing water from the sludge collected by the dredging device, and an equipment vehicle that supplies electricity, compressed air, etc. to the treatment device.

Incidentally, for example, in nuclear power plant buildings, sandbags containing adsorbents (e.g., zeolite) that adsorb radioactive materials are sometimes placed in the water to reduce the amount of radiation in the water. When recovering the contents of these sandbags, if the contents remain in the sandbags, the sludge recovery device of Patent Document 1 cannot recover the sediment.

Therefore, the inventors developed an underwater sediment recovery robot that "includes a robot body capable of moving underwater, a container attached to the robot body, a built-in pump mounted on the robot body and sucking up sediment through the container, and a tipped saw that is axially supported vertically on the front lower part of the robot body and can rotate freely" (Patent Document 2).

According to the underwater sediment recovery robot of Patent Document 2, the robot body rotates left and right while pressing a chip saw against the sandbags to break them, and the contents that spill out of the sandbags can be sucked up and recovered by the robot body's built-in pump. Therefore, even if the contents are contained in the sandbags, they can be efficiently recovered, and sediment recovery work can be performed quickly.

JP 2014-125754 A JP 2022-147083 A

The inventors have studied a method for recovering sediment stored in a container of the underwater sediment recovery robot (hereinafter referred to as the robot) of Patent Document 2. In detail, they have studied the following operation method: "The robot with the sediment stored in the container is moved to a collection site, and the container is removed from the robot. The sediment inside the container is then released to the collection site. After that, the robot is connected to a suction device installed at the collection site, and the zeolite inside the container is sucked up by the suction device."

Furthermore, the inventors considered an operation method in which sediment collected by the robot would be transported directly to a collection location, without storing it in a container, so that various collection methods could be applied depending on the local conditions. In this case, the discharge outlet of a hose connected to the robot would be placed at the collection location to transport the sediment. However, because the sediment is scattered over a wide area of the floor, the length of the hose can reach a maximum of 50 m or more. This means that the robot would move while pulling the hose, which could potentially get in the way of the robot's movement.

In view of these problems, the present invention aims to provide an underwater sediment recovery system and an underwater sediment recovery method that do not hinder the movement of the robot by the hose and that can reduce the load when the robot moves while pulling the hose.

To solve the above problems, a typical configuration of the underwater sediment recovery system according to the present invention is an underwater sediment recovery system that recovers and accumulates sediment from a flooded floor, and includes a robot that travels across the flooded floor to suck up the sediment, a discharge nozzle that is located on top of the robot and discharges the sucked up sediment to the outside, and a transport boat that can travel on the water surface of the floor, the transport boat having a bucket with an openable bottom, a float that floats the bucket on the water surface, and a screw that moves the bucket, and the discharge nozzle is installed in a position that allows it to discharge sediment into the bucket of the transport boat adjacent to the robot.

To solve the above problems, a typical configuration of the underwater sediment recovery method according to the present invention is an underwater sediment recovery method that uses the underwater sediment recovery system described above to recover and accumulate sediment from a flooded floor, and is characterized in that a transport boat is moved below the discharge nozzle of a robot, and the robot travels along the floor, sucking up the sediment while discharging it into the bucket of the transport boat, and then the transport boat is moved to a sediment accumulation location, and the bottom of the bucket is opened to release the sediment in the bucket to the accumulation location.

The present invention provides an underwater sediment recovery system and an underwater sediment recovery method that do not hinder the movement of the robot by the hose and can reduce the load on the robot when it moves while pulling the hose.

1 is a schematic diagram of a nuclear power plant building. FIG. 2 is an overall perspective view of the robot and the transport boat according to the embodiment. 1A to 1C are schematic diagrams illustrating how the recovery robot of the present embodiment travels underwater. 1 is a schematic diagram illustrating an underwater sediment recovery system according to an embodiment of the present invention. FIG. 1 is a diagram illustrating an underwater sediment recovery system according to a comparative example.

The preferred embodiment of the present invention will be described in detail below with reference to the attached drawings. The dimensions, materials, and other specific values shown in the embodiment are merely examples to facilitate understanding of the invention, and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid duplicated explanations, and elements not directly related to the present invention are not illustrated.

(Nuclear power plant building 10)
1 is a schematic diagram of a nuclear power plant building 10. In this embodiment, the nuclear power plant building 10 is exemplified as a facility for recovering sediment, but the present invention is not limited to this. The sediment recovery robot according to the present embodiment (hereinafter, referred to as the robot 100) can be suitably used in other facilities as long as sediment accumulates in water.

As shown in FIG. 1, the nuclear power plant building 10 is a building with multiple floors above ground and multiple floors underground (FIG. 1 illustrates a building with two floors above ground and two floors underground). The 1st floor is the entrance to the ground, and stagnant water is stored on the most underground floor, B2F. To adsorb the radioactive materials in the stagnant water, sandbags 12 filled with adsorbent material (e.g., zeolite) are installed on B2F. The robot 100 of this embodiment collects the adsorbent material that has settled in the water as sediment.

The robot 100 is placed on B2F of the nuclear power plant building 10. The robot 100 is carried into B2F by an overhead crane 14 installed on the ceiling of the 1st floor. When the robot 100 arrives at B2F, it detaches from the hook 16 and moves underwater on its own. A float cable 18 is connected to the robot 100, which receives power from a power supply panel 20 and transmits camera image data and signals from various sensors to a remote control device 22.

The overhead crane 14 shown in FIG. 1 carries the robot 100 into and out of the water. In detail, in this embodiment, the robot 100 is carried from the 1st floor to the B2 floor while suspended from the overhead crane 14. The robot 100 collects sediment while traveling underwater. After the collection operation, the float cable 18 of the robot 100 is wound by the winding device 24, and the robot 100 is washed by the shower 26, and then the robot 100 is pulled up by the hook of the crane 14 and carried out.

(Robot 100)
2 is an overall perspective view of the robot 100 and the transport boat 200 of this embodiment. For ease of understanding, the robot 100 used in the underwater sediment recovery system according to this embodiment will be described first.

The robot 100 shown in FIG. 2 travels on a flooded floor (B2F is exemplified in this embodiment) and sucks up sediment that has settled on the floor. The robot 100 includes a robot body 110 capable of travelling underwater, a float 140, a sediment suction mechanism 150, a discharge nozzle 156, a detachment mechanism 160, a screw 190, and a robot control unit 102.

As shown in FIG. 2, the robot 100 is configured to include a frame 120 and crawlers 130. The frame 120 is configured with an upper frame 122 that constitutes the upper part, and a lower frame 124 that constitutes the lower part. The upper frame 122 is provided with a float 140, and the robot body 110 is configured on the lower frame 124.

The robot body 110 has a sediment suction mechanism 150 mounted on the lower frame 124. The sediment suction mechanism 150 is configured to include a suction port 152 and a suction pump 154, and collects sediment from the bottom of the water. The suction port 152 is, for example, a suction nozzle, and is disposed between the crawlers 130 below the robot body 110. The suction pump 154 is connected to the suction port 152 via a connecting hose 154a. As a result, when the suction pump 154 is driven, sediment from the bottom of the water is sucked into the suction port 152 and collected.

If it is desired to remove the contents of the sediment from the sandbag 12 when the contents are contained in the sandbag 12, the crawler 130 may be used to trample the sandbag 12, tearing it open, and then the contents may be collected from the suction port 152. Alternatively, a cutting member such as a chip saw may be attached to the front of the lower part of the robot body 110. In this case, the chip saw may be used to tear the sandbag 12, and the contents may be collected from the suction port 152.

As shown in FIG. 2, a float 140 is disposed inside the upper frame 122. The float 140 is a hollow housing with air sealed inside. This allows the float 140 to act as a source of buoyancy, making it possible to float the robot 100 in water.

The float 140 can accommodate electrical equipment (not shown), such as a circuit board or an imaging device. In this embodiment, the robot control unit 102, which is connected to a remote control device 22 (see FIG. 1) and controls the operation of the robot 100, is accommodated inside the float 140. This makes it possible to effectively prevent electrical equipment from breaking down due to flooding.

A discharge nozzle 156 is also disposed on the top of the robot 100, i.e., on the upper frame 122. The discharge nozzle 156 discharges the sediment sucked up by the robot 100 (strictly speaking, the sediment suction mechanism 150) to the outside of the robot 100. The discharge nozzle 156 is connected to the suction pump 154 by a connecting hose 158. This maintains the connection between the suction pump 154 and the discharge nozzle 156 even when the upper frame 122 moves away from and toward the lower frame 124 (raising and lowering).

The robot body 110 and the float 140 described above are connected to each other so that they can be attached and detached by a detachment mechanism 160. As shown in FIG. 2, the robot 100 of this embodiment has a screw 190 that propels the robot body 110 through water. For example, a screw 190 that is integrated with a motor can be suitably used as the screw 190. FIG. 2 shows an example of a configuration in which two screws 190 are arranged on the sides and two screws 190 (one is not visible) are arranged on the rear, but this is not limiting, and the number of screws 190 may be changed as necessary.

Figure 3 is a schematic diagram illustrating the robot 100 of this embodiment moving underwater. In Figure 3, the depth of the stagnant water (from the water surface 40a to the water bottom 40b) is assumed to be about 1.5 m. In the robot 100 of this embodiment, during normal movement, the attachment/detachment mechanism 160 is extended to separate the float 140 from the robot body 110 as shown in Figure 3(a). This allows the robot 100 to move along the water bottom 40b using the crawlers 130.

When the presence of an obstacle 12a ahead is detected, the robot control unit 102 contracts the attachment/detachment mechanism 160. This causes the float 140 to approach the robot body 110 and become submerged, and the entire robot 100 floats up due to the buoyancy of the float 140.

Then, with the float 140 in close proximity, the robot body 110 is propelled through the water by the screw 190, and overcomes the obstacle 12a as shown in FIG. 3(c). In this way, the robot 100 of this embodiment can overcome the obstacle 12a present in the water by utilizing the buoyancy of the float 140, so that the work of recovering sediment in the water can be carried out efficiently.

In addition, as in the robot 100 of this embodiment, buoyancy acts on the float 140, so even if the robot 100 tilts, it will not fall over and can return to the correct posture. This makes it possible to maintain the posture of the robot 100 in a stable state.

(Underwater Sediment Collection System)
4 is a schematic diagram illustrating an underwater sediment recovery system according to this embodiment (hereinafter, referred to as recovery system 100a). In this embodiment, the recovery system 100a will be described in detail, and an underwater sediment recovery method using the same will also be described.

The recovery system 100a of this embodiment shown in FIG. 4 recovers sediment from a flooded floor (B2F) and accumulates it at an accumulation location P. The recovery system 100a of this embodiment includes the robot 100 described above, a discharge nozzle 156 provided on the robot 100, and a transport boat 200. Details of the robot 100 will not be explained here, and details of the discharge nozzle 156 will be described later.

The transport boat 200 can travel on the water surface 40a of the flooded floor, loads the sediment S sucked up by the robot 100, and transports it to the collection site P. As shown in Figures 2 and 4, the transport boat 200 includes a bucket 210, a float 220, and a screw 230.

The bucket 210 has an open top and an openable bottom 212 for carrying sediment S. The float 220 is attached to the side 214 of the bucket 210 and provides buoyancy to the bucket 210. The screw 230 is attached to the bucket 210 and is a driving source that propels the bucket 210 and the transport boat 200. The float 220 enables the transport boat 200 to float on the water surface 40a, and the screw 230 enables the transport boat 200 to travel on the water surface.

Figure 5 is a diagram illustrating an underwater sediment recovery system (hereinafter referred to as recovery system 80) of a comparative example. Note that common elements between the recovery system 100a of this embodiment and the recovery system 80 of the comparative example are given the same reference numerals and will not be described.

As shown in FIG. 5, in the comparative example collection system 80, one collection hole 52 and one transfer hole 60 are formed in the floor 50, and one transfer hose 32 supported by a hose reel 30 is inserted through them. One end of the transfer hose 32 is directly connected to the robot 100, and the other end is disposed at the collection location P.

In the comparative example recovery system 80 shown in FIG. 5, the robot 100 travels across the entire flooded floor to recover sediment, while at the same time transferring the sediment to a collection location P via a transfer hose 32. Because the transfer hose 32 needs to reach the entire flooded floor, its length can be up to 50 m or more, depending on the size of the floor. This places a heavy load on the robot 100 as it moves while pulling the transfer hose 32, and there is a risk that the transfer hose 32 will impede the movement of the robot 100.

In the recovery system 100a of this embodiment, the sediment S is recovered using a robot 100 that travels underwater to suck up the sediment S, and a transport boat 200 that travels on the water surface 40a to transport the sediment S. A feature of this embodiment is that the discharge port 156a of the discharge nozzle 156 of the robot 100 is installed in a position that allows the discharge of the sediment S into the bucket 210 of the transport boat 200 adjacent to the robot 100.

When recovering sediment S from a flooded floor, as shown in FIG. 4, the transport boat 200 moves so that the top surface of the bucket 210 is positioned below the discharge port 156a of the discharge nozzle 156 of the robot 100. At this time, the transport boat 200 is urged toward the robot 100 by the propulsive force of the screw 230, thereby positioning the bucket 210 and the discharge port 156a of the discharge nozzle 156.

When the transport boat 200 is placed in an adjacent position, the robot 100 travels along the floor, sucking up the sediment S and discharging it into the bucket 210 of the transport boat 200. At this time, the transport boat 200 is biased toward the robot 100, so when the robot 100 moves, the transport boat 200 also moves following it. In addition, the bottom surface 212 of the bucket 210 of the transport boat 200 is in a closed state.

When the sediment S discharged from the robot 100 into the bucket 210 reaches a predetermined amount, the transport boat 200 leaves the robot 100 and moves to the collection location P for the sediment S. The transport boat 200 then opens the bottom surface 212 of the bucket 210 and releases the sediment S in the bucket 210 to the collection location P. As a result, the sediment on the flooded floor is collected by the robot 100, transferred (transported) by the transport boat 200, and collected at the collection location P.

As described above, according to the recovery system 100a of this embodiment and the underwater sediment recovery method using the same, the sediment S sucked up by the robot 100 can be transferred to the collection site P without using the transfer hose 32. Therefore, the load of the transfer hose 32 on the robot 100 is reduced, and the transfer hose 32 does not impede the movement of the robot 100. Therefore, the robot 100 can move around the floor appropriately, and the sediment S can be efficiently recovered.

In this embodiment, the transport boat 200 moves to the collection location P when a predetermined amount of sediment S is loaded into the bucket 210, but the present invention is not limited to this. For example, it is also possible to configure the transport boat 200 to start moving to the collection location P based on other conditions, such as when the robot 100 has been discharging the sediment S for a predetermined period of time.

In addition, in this embodiment, a configuration in which one transport boat 200 is used for one robot 100 is illustrated, but this is not limited to this. For example, multiple transport boats 200 may be used for one robot 100, and the number of robots 100 and the number of transport boats 200 may be changed appropriately as necessary.

Although the preferred embodiment of the present invention has been described above with reference to the attached drawings, it goes without saying that the present invention is not limited to the examples described. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

The present invention can be used as an underwater sediment recovery system that recovers and accumulates sediment from flooded floors, and as an underwater sediment recovery method using the same.

10...nuclear power plant building, 12...sandbag, 12a...obstacle, 14...ceiling crane, 16...hook, 18...float cable, 20...power panel, 22...remote control device, 24...winding device, 26...shower, 30...hose reel, 32...transfer hose, 40a...water surface, 40b...water bottom, 50...floor, 52...recovery hole, 60...transfer hole, 80...recovery system, 100...robot, 100a...recovery system, 102...robot control unit, 110...robot body, 12 0...frame, 122...upper frame, 124...lower frame, 130...crawler, 140...float, 150...sediment suction mechanism, 152...suction port, 154...suction pump, 154a...connecting hose, 156...discharge nozzle, 156a...discharge port, 158...connecting hose, 160...detaching mechanism, 190...screw, 200...transport boat, 210...bucket, 212...bottom, 214...side, 220...floating body, 230...screw, P...accumulation location, S...sediment

Claims (2)

1. An underwater sediment collection system for collecting and accumulating sediment from a flooded floor, comprising:
a robot that travels on the flooded floor and sucks up the sediment;
a discharge nozzle disposed on an upper portion of the robot for discharging the sucked sediment to the outside;
A transport boat capable of traveling on the water surface of the floor;
Equipped with
The transport boat comprises:
A bucket with an openable bottom and
A float that floats the bucket on the water surface;
A screw that moves the bucket;
having
The underwater sediment recovery system, wherein the discharge nozzle is installed at a position where the discharge nozzle can discharge the sediment into a bucket of the transport boat adjacent to the robot. 13. An underwater sediment recovery method for recovering and accumulating sediment from a flooded floor using the underwater sediment recovery system according to claim 1, comprising:
moving the transport boat under a discharge nozzle of the robot;
The robot travels on the floor, sucking up the sediment, and discharging the sucked up sediment into a bucket of the transport boat.
moving the transport boat to a collection site for the sediment;
A method for recovering underwater sediment, comprising opening the bottom of the bucket and discharging the sediment within the bucket to the collection location.

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