Inspection system and inspection method
The inspection system and method facilitate rapid and safe tank inspection by using a robot and controlled gas ports to replace gases within a sealed mechanism, addressing the inefficiencies and safety concerns of traditional methods.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- MODEC
- Filing Date
- 2025-01-16
- Publication Date
- 2026-07-23
Smart Images
Figure JP2025001113_23072026_PF_FP_ABST
Abstract
Description
Inspection System and Inspection Method
[0001] The present invention relates to an inspection system and an inspection method for a tank in which liquefied natural gas or the like is stored, and more particularly to an inspection system and an inspection method capable of shortening the inspection period of the tank.
[0002] Various inspection methods for a tank storing liquefied natural gas or the like have been proposed (see, for example, Patent Document 1). The inspection method described in Patent Document 1 promoted the gasification of the liquefied natural gas inside the tank by supplying heated nitrogen gas to the tank. Thereby, the period until the liquefied natural gas was discharged from the tank was shortened.
[0003] The inspection method described in Patent Document 1 can promote the gasification of liquefied natural gas, but even in this case, a considerable period was required until all the natural gas inside the tank was discharged to the outside. Also, after replacing the liquefied natural gas in the tank with nitrogen gas, the operator can start inspecting the inside of the tank only after further replacing this nitrogen gas with air. A considerable period was also required for the replacement between nitrogen gas and air.
[0004] In the case of a tank storing crude oil, after discharging the crude oil to the outside, it was necessary to wash the inside of the tank, perform replacement with an inert gas, and then perform re-replacement with air. In this case, even if the inert gas was heated, the period required for the inspection work could not be shortened.
[0005] Japanese Patent Application Laid-Open No. 10-160098
[0006] The present invention has been made in view of the above problems, and an object thereof is to provide an inspection system and an inspection method capable of shortening the inspection period of a tank.
[0007] An inspection system for achieving the above objectives comprises a robot that performs work inside a tank and an insertion mechanism connected to the tank for inserting the robot into the tank, wherein the insertion mechanism has a main body having a cavity inside, a first opening configured to allow communication between the inside and outside of the main body, a second opening configured to allow communication between the inside of the main body and the tank, and a connecting port that allows the movement of material between the inside and outside of the main body, the connecting port having a gas connecting port used when replacing the gas inside the main body with another gas.
[0008] An inspection method for achieving the above objective is an inspection method using an inspection system comprising a robot that performs work inside a tank and an insertion mechanism connected to the tank for inserting the robot into the tank, wherein the insertion mechanism has a main body having a cavity inside, a first opening / closing port configured to allow communication between the inside and outside of the main body, a second opening / closing port configured to allow communication between the inside of the main body and the tank, and a connecting port that allows the movement of a substance between the inside and outside of the main body, and comprises a replacement step in which the gas inside the main body is replaced with another gas through the connecting port while the first and second opening / closing ports are closed, an insertion step in which the second opening / closing port is opened and the robot is inserted into the tank, a work step in which the robot performs work inside the main body, a recovery step in which the robot is recovered into the main body and the second opening / closing port is closed, and a re-replacement step in which the gas inside the main body is replaced with another gas through the connecting port.
[0009] According to the present invention, inspection of the tank by a robot can be started without performing gas replacement work inside the tank. This is advantageous for shortening the tank inspection period.
[0010] Figure 1 is an explanatory diagram illustrating the external appearance of a tank to which the inspection system is applied. Figure 2 is an explanatory diagram illustrating an overview of the inspection system. Figure 3 is an explanatory diagram illustrating the flow of the inspection method using the inspection system. Figure 4 is an explanatory diagram illustrating the state of the cleaning work. Figure 5 is an explanatory diagram illustrating a modified example of Figure 2. Figure 6 is an explanatory diagram illustrating the state of the inspection work.
[0011] The inspection system and inspection method will be described below based on the embodiment shown in the figure.
[0012] As illustrated in Figure 1, the inspection system 1 is installed in, for example, a tank 2 of an FPSO (Floating Production Storage and Offloading system) and used to inspect the inside of the tank 2. The tank 2 in which the inspection system 1 is used is not limited to the above, but can be any tank that requires inspection. Specifically, the tank 2 can consist of a tank of an FSO (Floating Storage and Offloading system), a ship's fuel tank, an oil tanker's cargo tank, or a tank installed on land. The inspection system 1 comprises a robot 3 that performs work inside the tank 2 and an insertion mechanism 4 that is connected to the tank 2 and lowers the robot 3 into the tank 2. In Figure 1, for illustrative purposes, the robot 3 positioned inside the insertion mechanism 4 is shown by a dashed line.
[0013] As illustrated in Figure 2, the input mechanism 4 includes a main body 5 with an internal cavity, a first opening / closing port 6 configured to allow communication between the inside and outside of the main body 5, a second opening / closing port 7 configured to allow communication between the inside of the main body 5 and the tank 2, and a connecting port 8 that allows the movement of substances between the inside and outside of the main body 5. The connecting port 8 has a gas connecting port 8a used when replacing the gas inside the main body 5 with another type of gas. In Figure 2, the inside of the main body 5 is shown in a visible state for illustrative purposes.
[0014] The robot 3 located inside the main body 5 includes at least one of either a cleaning robot 3a that collects waste such as crude oil residue inside the tank 2, or an inspection robot 3b that inspects the condition of the walls and other surfaces inside the tank 2.
[0015] The cleaning robot 3a has, for example, a mobile part such as wheels or tracks for traveling on the bottom surface of the tank 2, and a recovery part such as a suction port for sucking up waste accumulated on the bottom surface of the tank 2. The inspection robot 3b is composed of, for example, a flyable device such as a drone. The inspection robot 3b has, for example, a mobile part such as a propeller for flying inside the tank 2, and a shooting unit for acquiring images of the bottom and sides of the tank 2. The configuration of the robot 3 is not limited to the above. The robot 3 should be composed of a device that can perform the work necessary for inspecting the tank 2 inside the tank 2.
[0016] A single robot 3 may be configured to perform both waste collection and inspection of the inside of the tank 2. Robot 3 may also be configured to perform tasks other than cleaning and inspection.
[0017] The main body 5 of the input mechanism 4 is composed of, for example, a rectangular box. The walls of the main body 5 can be made of, for example, steel. The shape and material of the main body 5 are not limited to those described above and can be changed as appropriate. The main body 5 may be formed into a cylindrical shape or a polygonal tube shape, for example. The main body 5 may be made of, for example, synthetic resin.
[0018] As illustrated in Figure 2, the main body 5 has, for example, a first opening 6 on its top surface and a second opening 7 on its bottom surface. The positions where the first opening 6 and the second opening 7 are formed are not limited to those shown above. Both or one of the first opening 6 and the second opening 7 may be formed on the side of the main body 5. When the second opening 7 is formed on the side of the main body 5, the loading mechanism 4 is connected to the side of the tank 2.
[0019] It is desirable that the main body 5 has an airtight structure to prevent internal gas from leaking to the outside. However, it is not a mandatory requirement for the main body 5 to have an airtight structure.
[0020] The loading mechanism 4 is configured to be connected to an opening 9, such as a manhole, in the tank 2. In Figure 1, the opening 9 is shown with a dashed line for illustrative purposes. When viewing the opening 9 from the outside to the inside of the tank 2, it is desirable that the loading mechanism 4 be at least 0.5 times and no more than 2.0 times the size of the opening 9. Specifically, when viewing the opening 9 in the vertical direction in Figure 1, it is desirable that the main body 5 of the loading mechanism 4 be at least 0.5 times and no more than 2.0 times the size of the opening 9 in a direction perpendicular to the vertical direction (for example, the left-right direction in Figure 1). In the embodiment illustrated in Figure 1, the main body 5 is the same size as the opening 9.
[0021] Since the main body 5 of the loading mechanism 4 is formed to be relatively small, it can be transported and attached to and detached from the tank 2 relatively easily. The size of the loading mechanism 4 is not limited to the above. It is not prevented that the loading mechanism 4 be configured to be larger than twice the size of the opening 9.
[0022] The first opening 6 and the second opening 7 are configured to be openable and closable by a hinge 6a installed at the end, for example. The first opening 6 and the second opening 7 may also be configured to be openable and closable by a sliding part 7a that slides horizontally, for example. In the embodiment illustrated in Figure 2, the first opening 6 is configured to be openable and closable by a hinge 6a, and the second opening 7 is configured to be openable and closable by a sliding part 7a.
[0023] The connection port 8 is composed of a valve installed on the side of the main body 5, for example. The number of connection ports 8 that the input mechanism 4 has is not limited to one. The input mechanism 4 may have multiple connection ports 8. One of the connection ports 8, the gas connection port 8a, is composed of a check valve, for example. As illustrated in Figure 2, the inspection system 1 may have a blower 10 connected to one of the gas connection ports 8a. This blower 10 can draw gas from inside the main body 5 to the outside. The inspection system 1 may also have a gas cylinder 11 connected to another gas connection port 8a. The gas cylinder 11 can supply any gas to the inside of the main body 5.
[0024] Next, the inspection method using inspection system 1 will be explained. As illustrated in Figure 3, inspection system 1 first involves installing the loading mechanism 4 into the opening 9 of the tank 2 (hereinafter sometimes referred to as installation step S10). Specifically, inspection system 1 is brought into the FPSO, and the loading mechanism 4 is installed into the opening 9 of the tank 2 to be inspected. Installation step S10 is not a mandatory component. If the loading mechanism 4 is pre-installed in the tank 2, installation step S10 is unnecessary. In this case, the loading mechanism 4 is installed in each tank 2 of the FPSO and is not removed.
[0025] Next, the robot 3 is positioned inside the main body 5 (this is sometimes referred to as the preparation step S20). Specifically, the first opening 6 opens, and the robot 3, which is used for cleaning and inspecting the tank 2, is positioned inside the main body 5. After the robot 3 is positioned inside the main body 5, the first opening 6 closes. The preparation step S20 is not a mandatory configuration requirement. If the robot 3 is already positioned inside the main body 5, the preparation step S20 is unnecessary. In this case, the robot 3 is positioned inside the main body 5 and is not removed from the main body 5 except for maintenance, etc.
[0026] Next, with the first opening 6 and the second opening 7 closed, the gas inside the main body 5 is replaced with another gas via the connecting port 8 (hereinafter sometimes referred to as replacement step S30). Specifically, for example, the air inside the main body 5 is replaced with an inert gas. An inert gas is a gas whose oxygen concentration is set to a predetermined level or lower, such as nitrogen gas. One gas connecting port 8a discharges the air inside the main body 5 to the outside by the operation of the blower 10. At the same time, the other gas connecting port 8a supplies the inert gas stored in the gas cylinder 11a to the inside of the main body 5. In replacement step S30, the combination of gases to be replaced is not limited to air and inert gas. It is changed as appropriate depending on the type of gas filling the inside of the main body 5 and the type of gas flowing from the tank 2 to the main body 5. The inspection system 1 may also be equipped with a gas generator connected to the gas connecting port 8a. The main body 5 is supplied with gas generated by the gas generator instead of the gas cylinder 11a for inert gas. If the gas supplied from the gas generator has sufficient pressure, the blower 10 may not be installed at the other gas connection port 8a. This is because the gas inside the main body 5 is pushed out through the other gas connection port 8a, which is configured with a check valve or the like.
[0027] Next, the second opening 7 is opened and the robot 3 is lowered into the tank 2 (hereinafter sometimes referred to as the lowering step S40). After the replacement of the gas inside the main body 5 (replacement step S30) is completed, the second opening 7 is opened. If crude oil is stored in the tank 2, the opening of the second opening 7 allows the inert gas inside the main body 5 to flow into the tank 2. Also, hydrocarbon gas inside the tank 2 flows into the main body 5.
[0028] If robot 3 consists of a cleaning robot 3a, the cleaning robot 3a is suspended by a wire or the like and sent to the bottom of tank 2. If robot 3 consists of a flightable inspection robot 3b such as a drone, the inspection robot 3b moves into the inside of tank 2 by flight.
[0029] Next, the robot 3 performs work inside the tank 2 (hereinafter sometimes referred to as work step S50). This work refers to, for example, the cleaning robot 3a collecting waste accumulated on the bottom of the tank 2. The cleaning robot 3a is configured to autonomously collect waste while moving inside the tank 2 under automatic control, for example, by being equipped with a battery. At this time, the cleaning robot 3a has a collection box for temporarily storing the waste.
[0030] The work involves, for example, the inspection robot 3b flying inside the tank 2 and acquiring images of the bottom and sides of the tank 2, or measuring the sides of the tank 2 with sensors. The inspection robot 3b is configured to fly inside the tank 2 under automatic control, for example, by being equipped with a battery. The inspection robot 3b is also configured to autonomously take pictures of the inside of the tank 2 with a camera or the like when flying along a pre-set route.
[0031] Next, the robot 3 is retrieved into the main body 5 and the second opening 7 closes (this is sometimes referred to as the retrieval step S60). The robot 3, having completed or temporarily suspended its work, is retrieved into the main body 5. Because the second opening 7 closes, no gas moves between the tank 2 and the main body 5 thereafter.
[0032] Robot 3 performs work inside tank 2 for a certain period of time, and when the remaining battery charge or the available capacity of the collection box falls below a predetermined level, it is lifted by a wire or the like and collected by the main body 5.
[0033] Next, the gas inside the main body 5 is replaced with another gas via the connecting port 8 (hereinafter sometimes referred to as the re-replacement step S70). Immediately after the recovery step S60, the inside of the main body 5 contains the gas introduced in the replacement step S30 as well as gas flowing in from the tank 2. Specifically, for example, the inside of the main body 5 contains inert gas and hydrocarbon gas. In the re-replacement step S70, this gas is replaced with, for example, air. In the re-replacement step S70, the gas inside the main body 5 is sucked out by the blower 10 via the gas connecting port 8a and recovered into a separately prepared recovery gas cylinder 11b or the like.
[0034] After the replacement step S70, the first opening 6 can be opened to safely remove the robot 3 from the main body 5. The robot 3 then has its battery and recovery box replaced.
[0035] If the robot 3 is composed of two or more types of robots, for example, a cleaning robot 3a and an inspection robot 3b, the inspection system 1 may also have a configuration in which, after the replacement step S70, the first opening / closing port 6 opens and robot 3 is replaced with another robot 3 (hereinafter sometimes referred to as the replacement step S80). In Figure 3, the replacement step S80 is shown with a dashed line for illustrative purposes.
[0036] If the robot 3 is composed of multiple types of robots 3, the robots 3 placed inside the tank 2 are replaced as appropriate in the replacement step S80 while performing the work. Specifically, after the cleaning work by the cleaning robot 3a is completed, the re-replacement step S70 is executed. After that, the cleaning robot 3a inside the main body 5 is removed from the main body 5, and the inspection robot 3b is placed inside the main body 5 in its place.
[0037] The system may also be configured such that, after the replacement step S80, the replacement step S30, the input step S40, the work step S50, the recovery step S60, and the re-replacement step S70 are executed. Specifically, the inspection robot 3b, which was replaced in the replacement step S80, is put into the tank 2 after the replacement step S30, similar to the cleaning robot 3a (input step S40), and performs inspection work inside the tank 2 (work step S50). After that, the inspection robot 3b is recovered into the main body 5 (recovery step S60), and the gas inside the main body 5 is replaced with another gas (re-replacement step S70). The re-replacement step S70 makes it possible to remove the inspection robot 3b from the main body 5. With the above, the inspection of the tank 2 using the inspection system 1 is completed.
[0038] With this configuration, since robot 3 is used to inspect tank 2, even if the inside of tank 2 is filled with a flammable gas such as hydrocarbon gas, cleaning and inspection of the inside of tank 2 can be performed without removing the gas. Removing the gas from inside tank 2 would normally take about a week, depending on the volume of tank 2. This period is unnecessary with inspection using inspection system 1. This is advantageous for shortening the inspection period of tank 2. It is also advantageous for avoiding problems such as air pollution caused by the complete release of gas from inside tank 2 into the atmosphere. For example, if the gas inside tank 2 is a greenhouse gas such as hydrocarbon gas, the impact on global warming can be mitigated.
[0039] With this configuration, since the main body 5 has a connecting port 8 (gas connecting port 8a), the gas inside the main body 5 can be replaced with any gas. When opening the second opening port 7, problems such as oxygen flowing into the gas inside the tank 2 can be avoided. Also, when opening the first opening port 6, problems such as the gas inside the tank 2 diffusing into the atmosphere can be avoided.
[0040] Specifically, if the inside of tank 2 is filled with flammable gases such as hydrocarbon gases, the system can prevent accidents such as ignition or explosion that could occur when oxygen (air) comes into contact with these flammable gases. The loading mechanism 4 can safely load the robot 3 into the inside of tank 2.
[0041] Furthermore, if the tank 2 is filled with gases that are toxic to humans or have a foul odor, this prevents the gas from diffusing into the atmosphere. Opening the first opening 6 allows the robot 3 to be safely removed from the main body 5. This is advantageous for improving the safety of workers performing tasks around the loading mechanism 4.
[0042] Furthermore, problems such as the gas inside tank 2 being released into the atmosphere and polluting the air can be avoided.
[0043] This configuration utilizes robot 3, eliminating the need for workers to enter tank 2 for cleaning or inspection. This is advantageous for improving worker safety. Cleaning and inspection can be performed without workers entering crude oil tanks, heavy oil tanks, or sewage treatment tanks that are filled with hydrocarbon gases.
[0044] According to this configuration, since the loading mechanism 4 only needs to be able to load the robot 3 into the tank 2, the loading mechanism 4 can be configured to be relatively small according to the size of the robot 3. This is advantageous for realizing miniaturization of the inspection system 1.
[0045] As illustrated in FIG. 3, when the robot 3 is composed of one type of robot, the replacement steps from step S30 to the re-replacement step S70 are repeatedly executed as necessary. Specifically, when it is necessary to replace the battery of the robot 3 or the like, the robot 3 can continue to work while replacing the battery by repeating the above steps.
[0046] When the robot 3 is composed of multiple types of robots, the replacement step S80 can be executed at an arbitrary timing when repeating the above steps. After the replacement step S80, the above steps are repeated by the replaced robot 3.
[0047] The second opening / closing port 7 may be composed of a sandwich valve whose opening and closing are controlled by sliding the sliding portion 7a inside the housing. With a configuration using a sandwich valve, the second opening / closing port 7 can be easily opened and closed from the outside of the main body 5, and the possibility of the gas inside the main body 5 leaking to the outside during this opening and closing can be reduced.
[0048] It is also possible to adopt a configuration in which, in parallel with the cleaning operation of the tank 2 by the cleaning robot 3a (operation step S50), an operation of evacuating the gas inside the tank 2 and replacing it with a safe gas (gas evacuation step S90) is executed. After the gas inside the tank 2 is replaced with a safe gas, an operator can enter the inside of the tank 2 and safely perform the remaining cleaning work and inspection work.
[0049] For example, if the gas inside tank 2, such as in FPSO tank 2, is a flammable gas such as hydrocarbon gas, measures to prevent the explosion of the gas inside tank 2 were generally taken during normal operation, i.e., when inspection work was not being performed. Specifically, as a countermeasure, an inert gas was supplied to the inside of tank 2 to make the gas composition inside tank 2 a low oxygen concentration state, for example, 8 vol% or less. When inspection work is performed in this tank 2, robot 3 performs work step S50 in a low oxygen concentration environment. Therefore, it is desirable that robot 3 be a low oxygen specification robot that has been confirmed to operate safely in a low oxygen concentration environment. Robot 3 may be equipped with a gas sensor such as an oxygen concentration meter to confirm that the oxygen concentration inside tank 2 is sufficiently low. Robot 3 may have a safety device that cuts off the power to robot 3 if the gas sensor shows a value above a preset threshold, for example, 8 vol%. At this time, the loading mechanism 4 may have a configuration to retrieve robot 3 into the main body 5 using a wire or the like used in loading step S40 (retrieval step S60).
[0050] The robot 3 that is introduced into the tank 2 by the introduction mechanism 4 may be one unit or multiple units. For example, by introducing multiple cleaning robots 3a into the tank 2 simultaneously, the time required for cleaning can be shortened. By introducing multiple inspection robots 3b into the tank 2 simultaneously, the time required for inspection can be shortened.
[0051] Depending on the type of tank 2, cleaning may not be necessary. In this case, the inspection system 1 may not have a cleaning robot 3a, but instead have, for example, only an inspection robot 3b.
[0052] As illustrated in Figure 2, the connecting port 8 has a gas connecting port 8a that discharges gas from inside the main body 5 and supplies inert gas into the main body 5, and the gas connecting port 8a may also have a switching unit 12 that switches the type of gas supplied into the main body 5.
[0053] The switching unit 12 has a configuration that switches the type of gas supplied to the inside of the main body 5 for one gas connection port 8a. The switching unit 12 is composed of a coupling that connects, for example, the piping connected to the gas connection port 8a. Alternatively, the switching unit 12 may be composed of a three-way valve.
[0054] The switching unit 12 connects the piping extending from the gas cylinder 11a filled with inert gas to the gas connection port 8a during the replacement step S30, for example. The switching unit 12 also connects the piping extending from the blower 10 that takes in atmospheric air to the gas connection port 8a during the re-replacement step S70.
[0055] With this configuration, the substitution step S30 fills the inside of the main body 5 with inert gas, thus preventing oxygen from flowing from the main body 5 into the tank 2. This is advantageous for improving safety during inspection work.
[0056] With this configuration, the re-substitution step S70 fills the inside of the main body 5 with air, thus preventing flammable or toxic gases from being released into the atmosphere from the main body 5. This is advantageous for improving safety during inspection work.
[0057] When the switching section 12 is composed of a coupling, it becomes easier to visually confirm the piping connected to the gas connection port 8a, thereby making it easier to prevent accidents in which unintended gas is mistakenly supplied to the inside of the main body 5.
[0058] As illustrated in Figure 2, the robot 3 may have a cleaning robot 3a that collects waste inside the tank 2, and the connecting port 8 may have a waste connecting port 8b to which a waste hose 13 extending from the cleaning robot 3a is connected, allowing the waste to be discharged to the outside of the main body 5.
[0059] The waste hose 13 connects the cleaning robot 3a to the inside of the waste connection port 8b. This waste connection port 8b is formed inside the main body 5. The waste connection port 8b is composed of, for example, an on / off valve. The inspection system 1 includes a pump 14 and a waste tank 15 connected to the outside of the waste connection port 8b.
[0060] The cleaning robot 3a collects waste from the bottom of the tank 2 and discharges the waste to the outside of the main body 5 via the waste hose 13. The waste is collected from the cleaning robot 3a to the waste tank 15 via the waste hose 13, for example, by negative pressure.
[0061] With this configuration, the cleaning robot 3a no longer needs to repeat the replacement step S30 to the re-replacement step S70 to perform cleaning while replacing the collection box. The cleaning robot 3a can continuously discharge the collected waste to the outside of the input mechanism 4 via the waste hose 13 and the waste connection port 8b. This improves the efficiency of the cleaning work performed by the cleaning robot 3a. This is advantageous for shortening the cleaning period of the tank 2.
[0062] The cleaning robot 3a may have a pump that operates using gas pressure to pump waste. This pump is connected to a gas pressure hose and receives compressed gas through another gas connection port 8a and the gas pressure hose. At this time, the waste collected by the cleaning robot 3a is collected into the waste tank 15 via the waste hose 13 using the power of the pump. The gas supplied to the pump from the gas connection port 8a is composed of, for example, an inert gas or air. If the gas supplied to the pump is an inert gas, problems such as an increase in the oxygen concentration inside the tank 2 can be avoided even if gas leaks into the tank 2 from the gas pressure hose.
[0063] As illustrated in Figure 4, the robot 3 may have a cleaning robot 3a that collects waste inside the tank 2, and the connecting port 8 may have a shielding connecting port 8c to which a shielding hose 16 extending from the cleaning robot 3a is connected, supplying shielding gas to the shielding hose 16.
[0064] The shielding hose 16 connects the cleaning robot 3a to the inside of the shielding connection port 8c. One end of the shielding hose 16 is positioned near the recovery section of the cleaning robot 3a. The shielding connection port 8c is formed inside the main body 5. The shielding connection port 8c is composed of, for example, a check valve. The inspection system 1 is connected to the outside of the shielding connection port 8c and includes a gas cylinder 11c for storing shielding gas. The shielding gas is composed of, for example, an inert gas such as nitrogen gas. In Figure 4, the gas connection port 8a, blower 10, etc. are omitted for illustrative purposes.
[0065] When the cleaning robot 3a performs its work, shielding gas is released from the end of the shielding hose 16. The shielding gas is released near the recovery unit of the cleaning robot 3a. The cleaning robot 3a recovers the waste in the recovery unit within the shielding gas atmosphere. The waste, along with the shielding gas, is recovered by the cleaning robot 3a and sent to the waste tank 15.
[0066] This configuration prevents the cleaning robot 3a from collecting gas from inside tank 2 along with the waste when collecting the waste. It prevents flammable or toxic gases from being collected in the waste tank 15 along with the waste. This is advantageous in preventing accidents where flammable gases leak from the waste tank 15. It is also advantageous in improving safety around the input mechanism 4.
[0067] In the embodiment illustrated in Figure 4, the cleaning robot 3a may not have a waste hose 13, and may be configured to collect waste into a collection box installed on the cleaning robot 3a. In this case, only a shielding hose 16 is connected to the cleaning robot 3a.
[0068] This configuration prevents the cleaning robot 3a from collecting flammable gases along with the waste into the collection box. It also prevents accidents such as flammable gases leaking from the collection box when the cleaning robot 3a or the collection box is removed from the input mechanism 4. This is advantageous for improving safety around the input mechanism 4.
[0069] As illustrated in Figure 5, the feeding mechanism 4 may also be configured to include a connection part 18 to which a power cable 17 extending from the robot 3 is connected and to which electricity is supplied to the robot 3, a gas sensor 19 for measuring the oxygen concentration inside the main body 5, and a shut-off part 20 that receives a signal from the gas sensor 19 and shuts off the supply of electricity to the connection part 18 when the oxygen concentration exceeds a preset threshold, such as 8 vol%.
[0070] The power cable 17 is configured to supply electricity to the connection part 18, for example, to the cleaning robot 3a. The robot 3 to which the power cable 17 is connected may be an inspection robot 3b or another robot. The power cable 17 is wound around a drum 21 installed on the main body 5, with one end connected to the robot 3 and the other end connected to the inside of the connection part 18. The drum 21 on which the power cable 17 is wound may be installed on the robot 3.
[0071] With this configuration, since the input mechanism 4 has a power cable 17, the robot 3 does not need to be equipped with a battery. This is advantageous for miniaturizing the robot 3.
[0072] The connection unit 18 may be configured to receive and transmit signals between itself and the robot 3, with signal lines extending from the robot 3 connected to it. Specifically, the connection unit 18 may be configured to receive signal lines that control the robot 3 and signal lines that transmit data from cameras and sensors mounted on the robot 3. In this case, the power cable 17 will include the signal lines. Alternatively, the transmission and reception of signals between the connection unit 18 and the robot 3 may be achieved wirelessly. Specifically, communication devices may be installed on both the connection unit 18 and the robot 3. In this case, the power cable 17 will not include the signal lines.
[0073] This configuration allows for the transmission and reception of signals between the robot 3 inside the loading mechanism 4 and an external worker. The worker can remotely control the robot 3 from outside the loading mechanism 4 and check the condition inside the tank 2 using a camera or the like.
[0074] The gas sensor 19 is installed, for example, on the inner side or top surface of the main body 5. The shut-off unit 20 is composed of, for example, a switch incorporated into the connection unit 18. The shut-off unit 20 can cut off the electricity supplied to the robot 3 based on a signal from the gas sensor 19. The shut-off unit 20 is connected to the gas sensor 19, for example, by a signal line. The transmission and reception of signals between the shut-off unit 20 and the gas sensor 19 may be achieved wirelessly. In addition to being configured to cut off the supply of electricity, the shut-off unit 20 may also be configured to cut off both electricity and signals.
[0075] The input mechanism 4 may also have an external connection part 18a installed outside the main body 5 to supply electricity to the connection part 18. The external connection part 18a is installed on the outside of the main body 5. An external cable 22 that supplies electricity to the input mechanism 4 and transmits and receives signals is connected to the external connection part 18a. The external connection part 18a is not a mandatory component. For example, if a relatively large power source such as a storage battery is installed inside the main body 5, the external connection part 18a is unnecessary. In this case, the connection part 18 is installed between the storage battery and the robot 3, enabling the power to be cut off by the cutoff part 20. Even if a large-capacity storage battery is difficult to mount on the robot 3, it can be installed inside the main body 5. Also, if the robot 3 performs work autonomously by automatic control, there is no need for an operator to remotely control the robot 3, so the external connection part 18a is unnecessary.
[0076] When the oxygen concentration inside the main body 5 exceeds a preset threshold, such as 8 vol%, the shut-off unit 20 cuts off the power supply to the robot 3. As a result, the robot 3 is not supplied with power from the connection unit 18. For example, in the replacement step S30, if the air inside the main body 5 is not sufficiently replaced with inert gas, the robot 3 will not receive power. Also, when the robot 3 is working inside the tank 2 (work step S50), if air flows into the main body 5 due to a malfunction of the input mechanism 4 or the like, the shut-off unit 20 stops supplying power to the robot 3.
[0077] If the oxygen concentration inside the main unit 5 exceeds a threshold, the oxygen inside the main unit 5 may mix with the flammable gas flowing into the main unit 5 from the tank 2, potentially causing ignition or explosion. In such a case, the shut-off unit 20 cuts off the power supply to the robot 3.
[0078] With this configuration, since the input mechanism 4 has a shut-off section 20, if the gas filling the tank 2 is a flammable gas and there is a risk of ignition, the shut-off section 20 can cut off the power supply to the robot 3. This prevents accidents such as sparks being generated from the connection section 18 or power cable 17 and igniting the gas. This is advantageous for improving safety during inspection work.
[0079] With this configuration, since the loading mechanism 4 has a connection part 18, electricity can be supplied from the loading mechanism 4 to the robot 3. This eliminates the need to replace the battery mounted on the robot 3, allowing the robot 3 to perform cleaning and inspection tasks continuously. This is advantageous for shortening the inspection period of the tank 2.
[0080] As illustrated in Figure 5, the loading mechanism 4 has a lifting section 23 that moves the robot 3 from the main body 5 into the tank 2, and the lifting section 23 may be configured to have a drum around which the waste hose 13 is wound and which allows for winding and unwinding of the waste hose 13.
[0081] In this embodiment, the lifting unit 23 is composed of a drum installed inside the main body 5. The drum is configured to allow winding and unwinding of the waste hose 13 by rotation.
[0082] During the loading step S40, the drum is rotated to extend the waste hose 13, causing the cleaning robot 3a to descend into the tank 2. At this time, the waste hose 13 supports the weight of the cleaning robot 3a. Even if the robot 3 does not have a flight function, it can be safely moved to the bottom of the tank 2. During the retrieval step S60, the drum is rotated to rewind the waste hose 13, causing the cleaning robot 3a to rise into the main body 5.
[0083] With this configuration, the cleaning robot 3 is suspended by the waste hose 13, allowing it to move safely between the inside of the main body 5 and the bottom of the tank 2.
[0084] Furthermore, with this configuration, the power cable 17 does not need to support the weight of the cleaning robot 3a, so there is no need to make it thick or increase its strength. The power cable 17 can be made of a relatively thin and relatively light cable. As illustrated in Figure 6, the power cable 17 is easily applicable to the inspection robot 3b. If the inspection robot 3b is composed of a flyable drone, the weight of the power cable 17 will not cause problems that would make flight difficult.
[0085] The drum constituting the lifting section 23 may have a configuration that allows for winding and unwinding of the shielding hose 16 instead of the waste hose 13. Alternatively, the drum constituting the lifting section 23 may have a configuration that allows for winding both the waste hose 13 and the shielding hose 16.
[0086] The lifting section 23 may consist of a drum and a wire wound around it. The robot 3 is suspended by the wire and moves between the tank 2 and the main body 5. If the loading mechanism 4 is installed near the bottom of the tank 2 and on its side, the lifting section 23 is not necessary. Also, if the robot 3 is a drone or the like with flight capabilities, the lifting section 23 is not necessary.
[0087] The inspection system 1 may not have a configuration that includes a blower 10, gas cylinder 11, pump 14, waste tank 15, etc., which are connected to the outside of the connection port 8. For example, if the inspection system 1 is installed in an FPSO, the outside of the connection port 8 may be connected to equipment that the FPSO already has. The connection port 8 of the inspection system 1 may have a configuration in which the outside is connected to equipment that is already arranged around the tank 2. This configuration reduces the amount of equipment attached to the inspection system 1, thus enabling miniaturization of the inspection system 1.
[0088] 1 Inspection system 2 Tank 3 Robot 3a Cleaning robot 3b Inspection robot 4 Input mechanism 5 Main body 6 First opening 6a Hinge 7 Second opening 7a Sliding part 8 Connection port 8a Gas connection port 8b Waste connection port 8c Shielding connection port 9 Opening 10 Blower 11 Gas cylinder 11a Gas cylinder (for inert gas) 11b Gas cylinder (for recovery) 11c Gas cylinder (for shielding gas) 12 Switching part 13 Waste hose 14 Pump 15 Waste tank 16 Shielding hose 17 Power cable 18 Connection part 18a External connection part 19 Gas sensor 20 Shut-off part 21 Drum 22 External cable 23 Lifting part S10 Installation step S20 Preparation step S30 Replacement step S40 Input step S50 Work step S60 Recovery step S70 Re-replacement step S80 Replacement step S90 Draining step
Claims
1. An inspection system comprising a robot that performs work inside a tank, and a loading mechanism connected to the tank for loading the robot into the tank, wherein the loading mechanism has a main body having a cavity inside, a first opening configured to allow communication between the inside and outside of the main body, a second opening configured to allow communication between the inside of the main body and the tank, and a connecting port that allows the movement of material between the inside and outside of the main body, wherein the connecting port has a gas connecting port used when replacing the gas inside the main body with another gas.
2. The inspection system according to claim 1, wherein the robot is at least one of a cleaning robot that collects waste inside the tank, or an inspection robot that inspects the inside of the tank.
3. The inspection system according to claim 1, wherein the gas connection port has a configuration that discharges gas from inside the main body while supplying inert gas to the inside of the main body, and also has a switching unit that switches the type of gas supplied to the inside of the main body.
4. The inspection system according to any one of claims 1 to 3, wherein the robot has a cleaning robot that collects waste inside the tank, and the connecting port has a waste connecting port to which a waste hose extending from the cleaning robot is connected to discharge the waste to the outside of the main body.
5. The inspection system according to any one of claims 1 to 3, wherein the robot has a cleaning robot for collecting waste inside the tank, and the connecting port has a shielding connecting port to which a shielding hose extending from the cleaning robot is connected and which supplies shielding gas to the shielding hose.
6. The inspection system according to any one of claims 1 to 3, wherein the input mechanism comprises a connection part to which a power cable extending from the robot is connected and to which electricity is supplied to the robot; a gas sensor for measuring the oxygen concentration inside the main body; and a shut-off part that acquires a signal from the gas sensor and shuts off the supply of electricity to the connection part when the oxygen concentration exceeds a preset threshold.
7. The inspection system according to claim 6, wherein the input mechanism is installed outside the main body and has an external connection part that supplies electricity to the connection part.
8. The inspection system according to claim 4, wherein the loading mechanism has a lifting section for moving the robot from the main body into the tank, and the lifting section has a drum on which the waste hose is wound and which enables winding and unwinding of the waste hose.
9. The inspection system according to claim 5, wherein the loading mechanism has a lifting section for moving the robot from the main body into the tank, and the lifting section has a drum on which the shielding hose is wound and which enables the winding and unwinding of the shielding hose.
10. An inspection method using an inspection system comprising a robot that performs work inside a tank and an insertion mechanism connected to the tank for inserting the robot into the tank, wherein the insertion mechanism has a main body having a cavity inside, a first opening / closing port configured to allow communication between the inside and outside of the main body, a second opening / closing port configured to allow communication between the inside of the main body and the tank, and a connecting port that allows the movement of a substance between the inside and outside of the main body, and the inspection method comprising: a replacement step in which the gas inside the main body is replaced with another gas through the connecting port while the first and second opening / closing ports are closed; an insertion step in which the second opening / closing port is opened and the robot is inserted into the tank; a work step in which the robot performs work inside the tank; a recovery step in which the robot is recovered into the main body and the second opening / closing port is closed; and a re-replacement step in which the gas inside the main body is replaced with another gas through the connecting port.
11. The inspection method according to claim 10, further comprising a configuration in which, after the replacement step, a replacement step is performed in which the first opening is opened and the robot is replaced with another robot.
12. The inspection method according to claim 11, wherein the replacement step, the input step, the work step, the recovery step, and the re-replacement step are performed after the replacement step.