JP2019141765A - Injector and deposit removal method - Google Patents

Abstract

To rotate an injection part stably around the axis of a cylindrical tank, when injecting an injection object from the injection part onto an internal surface of the horizontal type cylindrical tank.SOLUTION: An injector for injecting an injection object toward an internal surface of a horizontal type cylindrical tank includes a central cylindrical part whose axis is arranged horizontally, an injection part supported rotatably around the axis to the central cylindrical part, for jetting out the injection object, a drive part for rotating the injection part around the axis, and a support part abutting on the internal surface of the cylindrical tank, for supporting the central cylindrical part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an injection device and a deposit removal method.

  For example, Patent Document 1 discloses a cleaning device that performs internal cleaning of a horizontal cylindrical tank in which an axis is placed in a horizontal state. Such a cleaning apparatus inserts a cleaning cylinder for injecting cleaning water from a manhole provided at the upper part of the cylindrical tank, and rotates the cleaning cylinder around the axis of the cylindrical tank inside the cylindrical tank. ing. By rotating the cleaning cylinder around the axial center of the cylindrical tank, the cleaning water can be sprayed over a wide range of the inner wall surface of the cylindrical tank.

JP-A-60-54778

  However, in the cleaning apparatus disclosed in Patent Document 1, a support cylinder is suspended from a manhole provided in the upper portion and inserted into the cylindrical tank, and is bent at the tip of an expansion / contraction lance connected to the support cylinder. The cleaning cylinder is supported. In other words, in the cleaning device disclosed in Patent Document 1, the bending structure composed of the support cylinder and the expansion / contraction lance is suspended and supported only by the manhole portion, and the cleaning cylinder is mounted at the tip of the bending structure supported by the suspension. It is structured to be rotated. For this reason, in the cleaning apparatus disclosed in Patent Document 1, the bending structure is shaken when the cleaning cylinder is rotated, and it is difficult to always rotate the cleaning cylinder around the axis of the cylindrical tank. .

  For example, instead of the cleaning liquid, it is conceivable to inject liquid nitrogen or an abrasive as an injection target for peeling the lining material provided on the inner wall surface of the cylindrical tank. Particularly in such a case, it is required to keep the distance from the injection unit that injects the injection target to the inner wall surface of the cylindrical tank within a certain range, and the injection unit is always centered on the axis of the cylindrical tank. It is necessary to rotate.

  The present invention has been made in view of the above-described problems, and when injecting an injection object from an injection unit onto the inner wall surface of a horizontally installed cylindrical tank, the injection unit is centered on the axis of the cylindrical tank. The purpose is to enable stable rotation.

  The present invention adopts the following configuration as means for solving the above-described problems.

  1st invention is an injection device which injects an injection target toward the inner wall surface of a horizontal type cylindrical tank, Comprising: With respect to the central cylinder part by which a shaft center is horizontally arranged, and the above-mentioned central cylinder part An injection unit that is supported rotatably about the axis and ejects the injection target, a drive unit that rotates the injection unit about the axis, and an inner wall surface of the cylindrical tank A configuration is adopted in which a support portion is provided that is in contact with and supports the central cylindrical portion.

  According to a second aspect of the present invention, in the first aspect of the invention, the support portion connects the wheel, which is slidably contacted to the inner wall surface of the cylindrical tank, and the wheel and the central tube portion. And a connecting rod tilting drive unit that tilts the connecting rod.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the ejecting section is linear along the radial direction centered on the axis, and is extendable and contractible. A configuration is adopted in which an injection nozzle is provided that is fixed to the tip of the part and injects the injection object.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the injection unit includes a stretchable portion tilting portion that tilts the stretchable portion.

  According to a fifth invention, in any one of the first to fourth inventions, the cylindrical tank is slidably connected to the central cylindrical portion and is formed in the cylindrical tank in contact with a side surface of the cylindrical tank. A configuration is adopted in which a seal portion covering the open portion is provided.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, a configuration is provided in which a collection unit that sucks and collects deposits deposited on the bottom of the cylindrical tank is employed.

  A seventh invention is a deposit removal method for removing deposits attached to the inner wall surface of a horizontal type cylindrical tank, and is directed horizontally toward an end in a direction along the axis of the cylindrical tank. An opening forming step for forming an opening to be opened, and an injection unit for injecting an injection object toward the inner wall surface of the cylindrical tank into the cylindrical tank through the opening. An injection unit arrangement step of arranging the injection unit in a state of being supported by a support unit in contact with the inner wall surface of the mold tank, and the injection target from the injection unit while rotating the injection unit around the axis of the cylindrical tank The structure which has the injection process which injects an object is employ | adopted.

  In an eighth aspect based on the seventh aspect, the opening is formed in an isolated space isolated from the outside in the opening forming step.

  According to a ninth invention, in the seventh or eighth invention, in the injection step, the opening of the cylindrical tank is covered with a seal portion from the outside of the cylindrical tank, and the injection unit is rotated. A configuration is adopted in which the spraying portion is moved along the axial center of the cylindrical tank while the central cylindrical portion that is movably supported and the shaft center is horizontally disposed is slid with respect to the seal portion.

  According to a tenth aspect of the present invention, in any one of the seventh to ninth aspects, a configuration is adopted in which the inside of the cylindrical tank is exhausted by an exhaust device in the injection step.

  In an eleventh aspect of the present invention, in any one of the seventh to tenth aspects, the deposit deposited on the bottom of the cylindrical tank is sucked and collected in the injection step or after the injection step. The configuration is adopted.

  According to the present invention, the injection unit is supported by the support unit that is in contact with the inner wall surface of the cylindrical tank, and even if the injection unit is rotated, the rotation axis of the injection unit is prevented from shaking. Can do. Therefore, according to the present invention, it is possible to stably rotate the injection unit around the axial center of the cylindrical tank.

It is a schematic block diagram containing the liquid nitrogen injection apparatus used for the internal decontamination method of the cylindrical tank in one Embodiment of this invention. It is a principal part enlarged view of FIG. It is explanatory drawing of the internal decontamination method of the cylindrical tank in one Embodiment of this invention. It is a schematic diagram for demonstrating the process of the internal decontamination method of the cylindrical tank in one Embodiment of this invention. It is a schematic diagram for demonstrating the process of the internal decontamination method of the cylindrical tank in one Embodiment of this invention. It is a schematic diagram for demonstrating the process of the internal decontamination method of the cylindrical tank in one Embodiment of this invention. It is a schematic diagram for demonstrating the process of the internal decontamination method of the cylindrical tank in one Embodiment of this invention.

  Hereinafter, an embodiment of an injection device and a deposit removal method according to the present invention will be described with reference to the drawings. In the following embodiments, an example will be described in which the spray device and the deposit removal method of the present invention are applied to the internal decontamination of a horizontal cylindrical tank.

  FIG. 1 is a schematic diagram showing a schematic configuration of a liquid nitrogen injection device 1 (injection device) for performing internal decontamination of a cylindrical tank T. The cylindrical tank T is a cylindrical tank centered on the axis LT, and is used by being placed so that the axis LT is in a horizontal state. The cylindrical tank T is made of a metal material such as steel, and a lining material made of FRP (Fiber-Reinforced Plastics) is formed on the inner wall surface. In the present embodiment, the lining material of the cylindrical tank T is peeled off by using the liquid nitrogen jet device 1 so as to remove the radioactive material adhering to the lining material from the cylindrical tank T together with the lining material.

  FIG. 2 is an enlarged view of the liquid nitrogen jet apparatus 1. As shown in this figure, the liquid nitrogen injection device 1 includes a carriage unit 2, a liquid nitrogen supply unit 3, a central cylinder unit 4, a rotating shaft 5, a drive unit 6, an injection unit 7, and a support unit. 8, a seal part 9, a recovery part 10, and a camera 11.

  The carriage unit 2 directly or indirectly supports the liquid nitrogen supply unit 3, the central cylinder unit 4, the rotating shaft 5, the drive unit 6, the injection unit 7, the support unit 8, the collection unit 10, and the camera 11. . The carriage unit 2 is a moving carriage that can move horizontally along the axis LT of the cylindrical tank T outside the cylindrical tank T. The carriage unit 2 includes a motor (not shown) and can be moved directly or remotely.

  The liquid nitrogen supply unit 3 is connected to a liquid nitrogen tank (not shown), pressurizes the liquid nitrogen X (injection target) supplied from the liquid nitrogen tank, and is arranged along the rotary shaft 5. Liquid nitrogen X whose pressure has been increased through 3b and the high-pressure hose 3c is supplied to the injection unit 7. The liquid nitrogen supply unit 3 includes a pressure increasing unit 3a that increases the pressure of the liquid nitrogen X, and the liquid nitrogen X that is disposed inside the central cylindrical unit 4 along the rotating shaft 5 and that is pressurized to the high pressure hose 3c. A high-pressure pipe 3b for guiding, and a high-pressure hose 3c that connects the high-pressure pipe 3b and the injection unit 7 and has flexibility are provided. For example, the boosting unit 3a is a boost pump for pumping the liquid nitrogen X, a pre-pump that primarily boosts the liquid nitrogen X sent from the boost pump, and the secondary pressure of the liquid nitrogen X that has been boosted to the secondary pressure. An intensifier pump for boosting pressure, a chiller for cooling the boosted liquid nitrogen X, and the like are provided. The length of the high-pressure hose 3c is set so as not to get entangled with the rotating shaft 5 while the rotating shaft 5 is rotated by 180 ° or more.

  The central cylinder part 4 is a cylindrical member having one end side held by the carriage part 2 so that the axial center La is horizontally arranged. Moreover, the central cylinder part 4 has the rotational shaft 5 arranged coaxially inserted therein. When the inner wall surface of the cylindrical tank T is decontaminated, the central cylinder portion 4 is gradually inserted into the cylindrical tank T as the carriage unit 2 moves. The length dimension in the direction along the axial center La of the central cylindrical portion 4 is set to be approximately the same as the length dimension in the direction along the axial center LT of the cylindrical tank T, for example. In the case where the decontamination work for the cylindrical tank T is performed separately from each of the end portions on both sides in the direction along the axis LT of the cylindrical tank T, the length in the direction along the axis La of the central cylinder portion 4 is determined. For example, the length dimension may be substantially half of the length dimension along the axis LT of the cylindrical tank T.

  The rotation shaft 5 is pivotally supported inside the central cylinder portion 4 so as to be rotatable around the axial center La of the central cylinder portion 4, and protrudes further forward from the distal end portion of the central cylinder portion 4. The jet part 7 can be installed in the head part 5a. Further, the rotating shaft 5 has a rear end portion connected to the driving unit 6 and is rotated by transmitting the power generated by the driving unit 6. The rotation shaft 5 is alternately rotated clockwise and counterclockwise around the axial center La of the central cylinder portion 4 by the drive unit 6 within a range where the high-pressure hose 3c is not entangled.

  The drive unit 6 is installed in the carriage unit 2 and rotates the rotation shaft 5 about the axis La of the central cylinder unit 4. Such a drive unit 6 includes a motor that generates rotational power based on a command input by remote operation, a transmission mechanism that transmits the rotational power generated by the motor to the rotating shaft 5, and the like. Further, the drive unit 6 rotates the rotating shaft 5 alternately in the clockwise direction and the counterclockwise direction within a range in which the high-pressure hose 3 c is not entangled with the rotating shaft 5.

  The injection portion 7 is supported by the head portion 5a of the rotation shaft 5 so as to be rotatable about the rotation axis of the rotation shaft 5, that is, the axis La of the central cylinder portion 4. . The injection unit 7 includes an injection nozzle 7a, an expansion / contraction part 7b, and an expansion / contraction part tilting part 7c. The injection nozzle 7a is connected to the high-pressure hose 3c of the liquid nitrogen supply unit 3, and is capable of injecting the liquid nitrogen X supplied via the high-pressure hose 3c. The expansion / contraction part 7b is a cylindrical member made linear along the radial direction centering on the axial center La of the central cylinder part 4, and can be extended and contracted by having, for example, a telescopic structure. The expansion / contraction part 7b adjusts the position of the injection nozzle 7a by expanding and contracting based on, for example, a command input by remote operation.

  The stretchable portion tilting portion 7c is connected to the root portion of the stretchable portion 7b, and tilts the stretchable portion 7b around the root portion. In the present embodiment, the expansion / contraction portion tilting portion 7c includes an insertion posture (posture indicated by an imaginary line in FIG. 2) in which the expansion / contraction portion 7b is in a posture along the axis La of the central cylinder portion 4, and the expansion / contraction portion 7b is in the center. The telescopic portion 7b is tilted between an injection posture (posture indicated by a solid line in FIG. 2) which is a posture orthogonal to the axial center La of the cylindrical portion 4. Such an extendable / contracting portion tilting portion 7c includes, for example, a stepping motor capable of adjusting a rotation angle based on a command input by remote operation, an axial support portion that pivotally supports the extending / contracting portion 7b and the like.

  The support portion 8 is installed in a region directed to the lower side of the peripheral surface of the central cylindrical portion 4, is in contact with the inner wall surface (bottom surface) of the cylindrical tank T, and supports the central cylindrical portion 4. The support portion 8 is disposed on the front side of the rear end portion of the central cylindrical portion 4 fixed to the carriage portion 2 in the direction along the axis La of the central cylindrical portion 4. In the present embodiment, as shown in FIG. 2, a plurality of support portions 8 are arranged in a direction along the axis La of the central cylinder portion 4. However, only one support portion 8 may be installed.

  As shown in FIG. 2, the support portion 8 includes wheels 8a, a connecting rod 8b, and a connecting rod tilting drive portion 8c. The wheel 8a is a driven wheel that is brought into contact with the inner wall surface of the cylindrical tank T so as to be able to roll, and is pivotally supported at the tip of the connecting rod 8b. The wheel 8a is provided with a plurality of irregularities on the contact surface with the cylindrical tank T. The height dimension of the protrusions in these uneven shapes is set to be higher than the height dimension of the obstacle assumed to be generated in the cylindrical tank T. As a result, it is possible to prevent the wheel 8a from interfering with an obstacle or the like to become unrotatable.

  The connecting rod 8 b is a rod member that connects the wheel 8 a and the central cylinder portion 4. The connecting rod tilt drive unit 8c is connected to the root portion of the connecting rod 8b, and tilts the connecting rod 8b around the root portion. In the present embodiment, the connecting rod tilt drive unit 8c includes an insertion posture (posture indicated by an imaginary line in FIG. 2) in which the connecting rod 8b is in a posture along the axial center La of the central tube portion 4, and the wheels 8a are cylindrical. The connecting rod 8b is tilted between a supporting posture (a posture shown by a solid line in FIG. 2) that contacts the inner wall surface of the mold tank T. Such a connecting rod tilting drive unit 8c includes, for example, a stepping motor capable of adjusting a rotation angle based on a command input by remote operation, a shaft support unit that pivotally supports the connecting rod 8b, and the like. .

  The seal portion 9 is slidably connected to the central cylinder portion 4 and is a portion that abuts the side surface of the cylindrical tank T and covers the opening T1 formed in the cylindrical tank T. The seal portion 9 includes a seal ring 9a, a dome portion 9b, and a pad portion 9c. The seal ring 9a is slidably contacted with the peripheral surface of the central cylindrical portion 4, and is held by the dome portion 9b. The seal ring 9 a is provided in an annular shape so as to be in contact with the entire area of the peripheral surface of the central cylindrical portion 4 when viewed from the direction along the axial center La of the central cylindrical portion 4. The dome portion 9b is set to a size capable of covering the opening portion T1 provided at the end portion of the cylindrical tank T, and has an opening portion in which the seal ring 9a is fitted at the center portion. Yes. A pad portion 9c is attached to the outer edge portion of the dome portion 9b. The pad portion 9c can be sucked to the end surface of the cylindrical tank T by, for example, vacuum suction. The pad portion 9c is provided in an annular shape so as to surround the opening T1 over the entire area when viewed from the direction along the axial center La of the central cylindrical portion 4.

  Such a seal portion 9 encloses the opening T1 from the outside of the cylindrical tank T by the dome portion 9b by adsorbing the pad portion 9c to the end surface of the cylindrical tank T so as to surround the opening T1. . This prevents an object inside the cylindrical tank T from leaking outside from the opening T1. In addition, the seal portion 9 is in contact with the center tube portion 4 so that the seal ring 9 a can slide. For this reason, it is possible to move the center cylinder part 4 in the direction along the axial center La by moving the carriage part 2 in a state of covering the opening part T1.

  Such a seal portion 9 can be divided into a plurality of parts so as to break the opening of the dome portion 9b. Thereby, when the injection part 7 and the support part 8 are allowed to pass through the opening T1 of the cylindrical tank T, it is possible to prevent the seal part 9 from interfering with the injection part 7 and the support part 8.

  The collection unit 10 sucks and collects the deposit accumulated on the bottom of the cylindrical tank T. For example, the recovery unit 10 recovers from the cylindrical tank T by sucking the lining material that is peeled off from the cylindrical tank T and deposited on the bottom by being sprayed with liquid nitrogen X. Such a recovery unit 10 includes a head unit 10a, a mounting rod 10b, a tube 10c, and a suction unit 10d.

  The head part 10a is a part that sucks in deposits by the negative pressure supplied from the suction part 10d, and is located in front of the wheel 8a of the support part 8 arranged in the foremost position and behind the injection part 7. Has been. When the lining material is peeled off while the central cylinder portion 4 is moved forward by the carriage 2, it becomes possible to suck the peeled lining material before it interferes with the wheels 8 a.

  The mounting rod 10b is a rod member that connects the head portion 10a and the connecting rod tilt drive portion 8c of the support portion 8. The mounting rod 10b can be tilted together with the connecting rod 8b of the support portion 8 by the connecting rod tilt driving portion 8c. The tube 10c has flexibility and connects the head portion 10a and the suction portion 10d. The tube 10c passes through the inside of the central cylinder portion 4 and connects the head portion 10a and the suction portion 10d. In order to more reliably prevent objects inside the cylindrical tank T from being discharged to the cart unit 2 side through the arrangement space of the tube 10c, a filter is arranged in the arrangement space of the tube 10c as necessary. Also good.

  The suction unit 10d is installed in the carriage unit 2 and forms a negative pressure for sucking the deposits in the cylindrical tank T. Such a suction unit 10d includes, for example, a turbo fan for generating negative pressure, a filter that separates deposits supplied from the head unit 10a and the tube 10c from gas, and the like.

  The camera 11 is for acquiring image data for grasping the situation of the liquid nitrogen jet apparatus 1 of the present embodiment that is operated by remote operation and outputting the image data to the outside, and is provided at a plurality of locations. Yes. In the liquid nitrogen ejecting apparatus 1 of the present embodiment, the cameras 11 are provided at the distal end portion of the central cylinder portion 4, the distal end of the telescopic portion 7 b of the ejecting portion 7, and the connecting rod 8 b of the support portion 8.

  In the liquid nitrogen ejecting apparatus 1 having such a configuration, the driving shaft 6 alternately rotates the rotating shaft 5 clockwise and counterclockwise about the axial center La of the central cylindrical portion 4, whereby the axial center The injection unit 7 is rotated around La. Further, by supplying liquid nitrogen X to the injection unit 7 via the high-pressure pipe 3b and the high-pressure hose 3c of the liquid nitrogen supply unit 3, the liquid is supplied from the tip of the injection nozzle 7a of the injection unit 7 rotated as described above. Nitrogen X is injected. At this time, the liquid nitrogen jet device 1 supports the central cylinder portion 4 from below by the support portion 8 in which the wheel 8a is in contact with the bottom portion of the cylindrical tank T. Further, the lining material peeled off from the cylindrical tank T when the liquid nitrogen X is injected is recovered from the inside of the cylindrical tank T by the recovery unit 10.

  Then, the internal decontamination method (attachment removal method) of the cylindrical tank T using such a liquid nitrogen injection apparatus 1 is demonstrated.

  When performing internal decontamination of the cylindrical tank T, for example, the cylindrical tank T placed in a predetermined storage area is transported to a decontamination temporary tent installed at another position. For example, as shown in FIG. 3, the cylindrical tank T installed in the storage area is transferred using the large crane 20 to the transport carriage 21 on which the tank fixing plate P is placed. As shown in FIG. 4, the transport carriage 21 is moved into the decontamination temporary tent 22. At this time, the opening / closing door 22a of the decontamination temporary tent 22 is opened, and the transport carriage 21 is moved into the decontamination temporary tent 22 through the opened opening / closing door 22a.

  When the cylindrical tank T is transported to the decontamination temporary tent 22, the cylindrical tank T is subsequently moved into a decontamination cell 23 installed in the decontamination temporary tent 22. Here, for example, a winch mechanism W connected to the tank fixing plate P is installed in the decontamination cell 23 and the transport carriage 21, and the roller conveyor 22 b installed in the decontamination temporary tent 22 is used for the decontamination cell 23. Moving. At this time, the opening / closing door 23a of the decontamination cell 23 is opened, and the cylindrical tank T is moved together with the tank fixing plate P onto the mounting table 23b of the decontamination cell 23 via the opened opening / closing door 23a.

  After the winch mechanism W is separated from the tank fixing plate P, an in-tank exhaust device 24 arranged outside the decontamination cell 23 is connected to the cylindrical tank T as shown in FIG. To negative pressure. Furthermore, the installation space of the decontamination cell 23 and the in-tank exhaust device 24 is connected to the second exhaust device 25 so that the gas in the installation space of the decontamination cell 23 and the in-tank exhaust device 24 can be exhausted. Note that a remote operation temporary house 26 in which an operation unit for remotely operating the liquid nitrogen jet device 1 is installed outside the decontamination temporary tent 22. A camera may be installed inside the cylindrical tank T as necessary. In this case, the camera can be easily placed inside the cylindrical tank T by inserting the camera from a portion (for example, a vent nozzle) of the cylindrical tank T to which the in-tank exhaust device 24 is connected.

  Subsequently, as shown in FIG. 6, an opening T1 is formed at the end of the cylindrical tank T (opening forming step). Here, an opening T1 that opens in the horizontal direction is formed at the end of the cylindrical tank T in the direction along the axis LT. By forming such an opening T1, the liquid nitrogen jet device 1 can be inserted into the horizontal cylindrical tank T from the horizontal direction.

  Note that most of the radioactive substance attached to the cylindrical tank T is attached to the lining material. Furthermore, when the opening T1 is formed, the inside of the cylindrical tank T is set to a negative pressure by the tank exhaust device 24. Thereby, it is possible to prevent the radioactive substance in the cylindrical tank T from leaking out of the cylindrical tank T when the opening T1 is formed. For this reason, when the opening T1 is formed, it is possible for a worker who has appropriately performed the protection to work relatively easily. The opening T1 is formed in the inside (isolation space) of the decontamination cell 23 isolated from the outside.

  Further, in the present embodiment, since the liquid nitrogen injection device 1 is inserted only from one side of the cylindrical tank T, the opening T1 is formed only at one end of the cylindrical tank T. However, when the liquid nitrogen injection device 1 is inserted alternately from both sides of the cylindrical tank T, an opening T1 is formed for each end in the direction along the axis LT of the cylindrical tank T. Also good. In such a case, of the two openings T1, the opening T1 into which the liquid nitrogen jet device 1 is not inserted is preferably sealed with another member. Furthermore, it is desirable to install a turntable mechanism on the mounting table 23b of the decontamination cell 23.

  Then, as shown in FIG. 7, the injection part 7 of the liquid nitrogen injection apparatus 1 is arrange | positioned with respect to the inside of the cylindrical tank T (injection part arrangement | positioning process). Here, the liquid nitrogen jet device 1 is disposed on the mounting table 23 b of the decontamination cell 23 so as to face the opening T 1 of the cylindrical tank T. Subsequently, by remotely operating the liquid nitrogen injection device 1 from the remote operation temporary house 26, the injection unit 7 and the leading support unit 8 are set to the insertion posture (posture indicated by the phantom line in FIG. 2), and the carriage unit 2 is moved toward the cylindrical tank T, and the carriage unit 2 is moved until the leading support portion 8 is inserted into the cylindrical tank T. Thereafter, the injection unit 7 is set to an injection posture (posture indicated by a solid line in FIG. 2), and the leading support portion 8 is set to a support posture (posture indicated by a solid line in FIG. 2). As a result, the wheel 8a of the leading support portion 8 is brought into contact with the inner wall surface of the cylindrical tank T, and the cylindrical portion is supported by the support portion 8 from below through the central cylinder portion 4 and the like. Arranged inside the tank T.

  In this way, the wheel 8a of the support portion 8 is brought into contact with the inner wall surface of the cylindrical tank T, so that the central cylindrical portion 4 that supports the rotating shaft 5 on which the injection portion 7 is installed is supported from below. The axial center La of the central cylindrical portion 4 can be reliably aligned with the axial center LT of the cylindrical tank T. In this way, after the axial center La of the central cylindrical portion 4 is aligned with the axial center LT of the cylindrical tank T, the seal portion 9 is attached to cover the opening T1 of the cylindrical tank T from the outside.

  In addition, when the liquid nitrogen X is not injected from the injection part 7, the possibility that the radioactive material and the lining material to which the radioactive material adheres will be reduced. For this reason, if the injection of the liquid nitrogen X from the injection unit 7 is stopped, and the inside of the cylindrical tank T is set to a negative pressure, the operator who has appropriately protected the attachment / detachment operation of the seal unit 9 It can be performed. However, the attaching / detaching operation of the seal portion 9 may be performed using a robot or the like.

  Subsequently, as shown in FIGS. 1 and 2, liquid nitrogen X is supplied from the injection unit 7 to the inner wall surface of the cylindrical tank T while rotating the injection unit 7 about the axis La of the central cylinder unit 4. Inject (injection process). Here, first, the position of the spray nozzle 7a relative to the inner wall surface of the cylindrical tank T is adjusted by remotely operating the telescopic portion 7b based on the image of the camera 11. Further, by rotating the rotating shaft 5 by the driving unit 6, the ejecting unit 7 is rotated, and further, the liquid nitrogen X is supplied from the liquid nitrogen supply unit 3 to the ejecting unit 7, thereby liquid from the tip of the ejecting nozzle 7 a. Nitrogen X is injected.

  When the liquid nitrogen X is jetted onto the inner wall surface of the cylindrical tank T in this way, the lining material holding the radioactive substance is peeled from the cylindrical tank T by the expansion force when the liquid nitrogen X is vaporized. Therefore, by spraying the liquid nitrogen X, the radioactive substance adhering to the cylindrical tank T can be removed and decontamination can be performed.

  Further, in the present embodiment, the opening T1 of the cylindrical tank T is covered with the seal portion 9 from the outside of the cylindrical tank while the injection unit 7 is rotated and the liquid nitrogen X is injected from the injection unit 7. In this state, the central cylinder portion 4 is gradually moved toward the inner side of the cylindrical tank T by moving the carriage portion 2. Thereby, a wide range of the cylindrical tank T is continuously decontaminated.

  When at least liquid nitrogen X is injected from the injection unit 7, the inside of the cylindrical tank T is brought into a negative pressure state by the in-tank exhaust device 24. Thereby, the liquid nitrogen X vaporized inside the cylindrical tank T is exhausted without leaking out of the cylindrical tank T.

  Further, the gas in the installation space of the inside of the decontamination cell 23 and the in-tank exhaust device 24 is exhausted by the second exhaust device 25. When the internal pressure of the cylindrical tank T rises due to some unforeseen circumstances, the internal gas of the cylindrical tank T is exhausted from the internal space of the decontamination cell 23 or the exhaust in the tank in order to prevent the seal portion 9 from being damaged. It is preferable to provide a vent mechanism for urgent discharge in the installation space of the device 24. In the unlikely event that such a vent mechanism operates, the interior of the decontamination cell 23 and the installation space of the in-tank exhaust device 24 are kept negative by the second exhaust device 25, It is possible to prevent the radioactive material leaking into the installation space of the in-tank exhaust device 24 from being released into the atmosphere.

  In the present embodiment, at least when the liquid nitrogen X is jetted from the jetting unit 7, the lining material deposited on the bottom of the cylindrical tank T is collected by the collecting unit 10 of the liquid nitrogen jetting apparatus 1. The lining material collected in this way is stored in the suction unit 10d of the collection unit 10.

  When the second support portion 8 is in a position where it interferes with the seal portion 9 in the process of causing the central cylinder portion 4 to enter the inside of the cylindrical tank T while sliding the seal ring 9 a of the seal portion 9. Once, the injection of the liquid nitrogen X is stopped, the seal portion 9 is removed from the cylindrical tank T, and the supporting portion 8 to be passed is inserted into the cylindrical tank T with the insertion posture.

  In the present embodiment as described above, the liquid nitrogen ejecting apparatus 1 is supported so as to be rotatable about the axial center La with respect to the central cylindrical part 4 in which the axial center La is horizontally disposed and the central cylindrical part 4. At the same time, the jetting part 7 for jetting the liquid nitrogen X, the driving part 6 for rotating the jetting part 7 around the axis La, and the inner cylindrical wall surface of the cylindrical tank T are supported and the central cylindrical part 4 is supported. And a support portion 8. According to this liquid nitrogen injection device 1, the injection unit 7 is supported by the support unit 8 that is in contact with the inner wall surface of the cylindrical tank T, and even if the injection unit 7 rotates, the injection unit 7 rotates. The axis can be prevented from shaking.

  In the method of internal decontamination of the cylindrical tank T using such a liquid nitrogen jet device 1, the opening T1 that opens in the horizontal direction is formed at the end in the direction along the axis LT of the cylindrical tank T. The injection unit 7 that is formed and injects liquid nitrogen X into the cylindrical tank T toward the inner wall surface of the cylindrical tank T through the opening T1 is in contact with the inner wall surface of the cylindrical tank T. It arrange | positions in the state supported by the part 8, and injects the liquid nitrogen X from the injection part 7, rotating the injection part 7 centering | focusing on the axial center LT of the cylindrical tank T. FIG. Therefore, according to the internal decontamination method of the cylindrical tank T of the present embodiment, it is possible to stably rotate the injection unit 7 around the axial center LT of the cylindrical tank T. From the injection unit 7 to the cylinder By always keeping the distance to the inner wall surface of the mold tank T constant, the lining material can be reliably peeled off.

  In the internal decontamination method for the cylindrical tank T according to the present embodiment, the opening T1 is formed in the cylindrical tank T in a space isolated from the outside. For this reason, when forming opening part T1, it can prevent that a part of lining material leaks outside.

  Further, in the internal decontamination method of the cylindrical tank T according to the present embodiment, the liquid nitrogen jet device 1 is slidably connected to the central cylindrical portion 4 and is in contact with the side surface of the cylindrical tank T so as to be cylindrical. A sealing portion 9 that covers the opening T1 formed in the tank T is provided, and when the liquid nitrogen X is sprayed, the opening T1 of the cylindrical tank T is covered with the sealing portion 9 from the outside of the cylindrical tank T. . For this reason, it can prevent that the lining material peeled outside the cylindrical tank T leaks out. That is, according to the internal decontamination method of the cylindrical tank T of the present embodiment, the cylindrical tank T itself can be used as an isolation wall that prevents radioactive substances from leaking outside.

  Furthermore, in the internal decontamination method of the cylindrical tank T of the present embodiment, the central cylindrical portion 4 that supports the injection portion 7 so as to be rotatable and the shaft center La is horizontally disposed slides with respect to the seal portion 9. The liquid nitrogen X is jetted while moving the jetting part 7 along the axis LT of the cylindrical tank T. For this reason, it becomes possible to inject liquid nitrogen X continuously over a wide range.

  Further, in the internal decontamination method of the cylindrical tank T of the present embodiment, when the liquid nitrogen X is jetted, the inside of the cylindrical tank T is exhausted by the in-tank exhaust device 24 (exhaust device) and is in a negative pressure state. It is said. For this reason, it can prevent that the lining material which peeled with the expansion force at the time of vaporizing liquid nitrogen X spouts outside the cylindrical tank T. FIG.

  Further, in the internal decontamination method of the cylindrical tank T of the present embodiment, the liquid nitrogen injection device 1 includes the recovery unit 10 and is deposited on the bottom of the cylindrical tank T by the recovery unit 10 while injecting the liquid nitrogen X. The lining material is sucked and collected. For this reason, according to the internal decontamination method of the cylindrical tank T of this embodiment, it becomes possible to collect | recover automatically the peeled lining material.

  Moreover, in this embodiment, the support part 8 of the liquid nitrogen jet apparatus 1 connects the wheel 8a abutting on the inner wall surface of the cylindrical tank T so as to be able to roll, and the wheel 8a and the central cylinder part 4. A rod 8b and a connecting rod tilt drive unit 8c that tilts the connecting rod 8b are provided. For this reason, according to the liquid nitrogen injection device 1, it is possible to change the posture of the support portion 8, and the support portion 8 can easily pass through the opening T1 formed in the cylindrical tank T. .

  Moreover, in this embodiment, the injection part 7 of the liquid nitrogen injection apparatus 1 is provided with the expansion-contraction part 7b which was linearly formed along the radial direction centering on the axial center La, and was made extendable. For this reason, according to the liquid nitrogen injection device 1, the tip position of the injection nozzle 7 a can be adjusted with respect to the inner wall surface of the cylindrical tank T.

  Moreover, in this embodiment, the injection part 7 of the liquid nitrogen injection apparatus 1 is provided with the expansion-contraction part inclination part 7c which inclines the expansion-contraction part 7b. For this reason, according to the liquid nitrogen injection device 1, it becomes possible to change the attitude of the expansion / contraction part 7b, and the injection part 7 can easily pass through the opening T1 formed in the cylindrical tank T. . Moreover, according to the liquid nitrogen injection apparatus 1, it is also possible to change the injection direction of the liquid nitrogen X as needed. For this reason, according to the liquid nitrogen injection device 1, for example, the liquid nitrogen X can be injected forward.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the spirit of the present invention.

  For example, in the said embodiment, the structure which uses liquid nitrogen X as an injection target was demonstrated. However, the present invention is not limited to this, and it is possible to employ a configuration in which water or an abrasive is jetted as a jetting object.

  Moreover, in the said embodiment, the structure which peels the lining material adhering to the inner wall face of the cylindrical tank T was demonstrated. However, the present invention is not limited to this. The present invention can be applied if the deposits are removed from the inner wall surface of the cylindrical tank T.

  Moreover, in the said embodiment, the structure by which the injection part 7 was rotated when the rotation shaft 5 pivotally supported by the center cylinder part 4 was rotated was demonstrated. However, the present invention is not limited to this, and without installing the rotating shaft 5, the injection unit 7 is installed in the central cylinder part 4, and the injection part 7 is rotated by rotating the central cylinder part 4. It is also possible to adopt a configuration for rotating.

  When water or the like is used as the injection target, the liquid nitrogen X can be injected at a low pressure. For this reason, for example, a flow path for guiding water or the like to the injection unit 7 is formed inside the rotation shaft 5, and water or the like is supplied from the water supply unit to the rotation shaft 5 via a rotary joint or the like. Water or the like may be supplied to the injection unit 7 via the shaft 5. In such a case, it becomes possible to continuously rotate the ejecting portion 7 in the same direction around the rotation shaft 5 about the axis La of the central cylindrical portion 4.

1 ... Liquid nitrogen injection device (injection device)
2 …… Carriage part 3 …… Liquid nitrogen supply part 4 …… Center cylinder part 5 …… Rotating shaft 5a …… Head part 6 …… Drive part 7 …… Injection part 7a …… Injection nozzle 7b …… Expandable part 7c ...... Extensible / contracting part tilting part 8 ... support part 8a ... wheel 8b ... connecting rod 8c ... connecting rod tilting drive part 9 ... seal part 9a ... seal ring 9b ... dome part 9c ... pad part 10 ... ... Recovery part 10a ... Head part 10b ... Mounting rod 10c ... Tube 10d ... Suction part 11 ... Camera 20 ... Large crane 21 ... Conveyor carriage 22 ... Decontamination temporary tent 22a ... Opening / closing door 22b ... ... Roller conveyor 23 ... Decontamination cell 23a ... Opening / closing door 23b ... Mounting table 24 ... Exhaust device in tank (exhaust device)
25 …… Second exhaust device 26 …… Temporary house for remote operation La …… Axis center LT …… Axis center P …… Tank fixing plate T …… Cylindrical tank T1 …… Opening W …… Winch mechanism X …… Liquid nitrogen (jetting object)

Claims (11)

An injection device that injects an injection target toward an inner wall surface of a horizontal cylindrical tank,
A central tube portion in which the shaft center is horizontally disposed;
An injection unit that is rotatably supported around the axis with respect to the central cylindrical unit and that ejects the injection target; and
A drive unit that rotates the injection unit about the axis; and
An injection apparatus comprising: a support portion that is in contact with an inner wall surface of the cylindrical tank and supports the central cylinder portion. The support part is
A wheel in contact with the inner wall surface of the cylindrical tank in a rollable manner;
A connecting rod for connecting the wheel and the central tube portion;
The injection device according to claim 1, further comprising: a connecting rod tilting drive unit that tilts the connecting rod. The injection unit is
A stretchable portion that is linear and stretchable along a radial direction centered on the axis;
The injection device according to claim 1, further comprising: an injection nozzle that is fixed to a distal end of the expansion and contraction unit and that injects the injection object.   The said injection part is provided with the expansion-contraction part inclination part which inclines the said expansion-contraction part, The injection apparatus of Claim 3 characterized by the above-mentioned.   2. A seal portion that is slidably connected to the central cylinder portion and that abuts against a side surface of the cylindrical tank and covers an opening formed in the cylindrical tank. The injection apparatus as described in any one of -4.   The injection device according to any one of claims 1 to 5, further comprising a collection unit that sucks and collects deposits accumulated on a bottom of the cylindrical tank. A deposit removal method for removing deposits attached to the inner wall surface of a horizontal cylindrical tank,
An opening forming step of forming an opening that opens in the horizontal direction at an end in a direction along the axis of the cylindrical tank;
An injection unit that injects an injection target toward the inner wall surface of the cylindrical tank into the cylindrical tank through the opening is supported by a support unit that is in contact with the inner wall surface of the cylindrical tank. An injection unit arranging step to arrange in a state of
And a jetting step of jetting the jetting object from the jetting part while rotating the jetting part about the axis of the cylindrical tank.   8. The deposit removing method according to claim 7, wherein, in the opening forming step, the opening is formed in an isolated space isolated from the outside. In the injection step,
Covering the opening of the cylindrical tank with a seal from the outside of the cylindrical tank,
The injection unit is moved along the axial center of the cylindrical tank while sliding the central tube portion having the shaft center horizontally disposed with respect to the seal portion while rotatably supporting the injection unit. The deposit removing method according to claim 7 or 8.   The deposit removal method according to any one of claims 7 to 9, wherein in the spraying step, the inside of the cylindrical tank is exhausted by an exhaust device.   The attachment according to any one of claims 7 to 10, wherein the deposit accumulated on the bottom of the cylindrical tank is sucked and collected in the spraying step or after the spraying step. Kimono removal method.

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