JP4660603B2 - Extubation jig and extubation method - Google Patents

Description

  The present invention relates to a tube extraction jig and a tube extraction method used when removing a heat transfer tube from a structure such as a heat exchanger provided with the heat transfer tube.

  Heat exchangers such as main turbine condensers and feed water heaters used in thermal power plants and nuclear power plants include a large number of heat transfer tubes using small-diameter pipes. Moreover, a heat exchanger is provided with the tube plate to which the edge part of the heat exchanger tube was fixed, and the some support plate arrange | positioned suitably in the longitudinal direction of a heat exchanger tube. Usually, the heat transfer tube is composed of a metal tube such as a steel tube or a copper tube.

  As heat transfer tubes age with long-term use, scale adhesion and corrosion occur. Therefore, the aged heat transfer tube is removed from the tube plate and the support plate and subjected to maintenance such as replacement.

  A tube extraction tool is known as a tool used when removing a heat transfer tube from a tube plate (for example, refer to Patent Document 1).

  Moreover, with the aging of the heat exchanger, the entire heat exchanger may be replaced with a new heat exchanger. In this case, a tube extraction tool is used in the work of disassembling the removed heat exchanger.

JP 2002-346856 A

  A heat exchanger used in a nuclear power plant is configured, for example, in a cylindrical shape having a diameter of about 2.5 m and a length of about 10.0 m, and about 4400 heat transfer tubes are accommodated therein. The heat transfer tube is held on the support plate every about 0.8 m. A nuclear power plant is equipped with about 15 such heat exchangers. In the future, along with the aging of existing heat exchangers, replacement with new heat exchangers will progress, and waste from the removed heat exchangers is expected to increase.

  Generally, a heat exchanger after being used in a nuclear power plant is dismantled, cut into small pieces, drummed and disposed of.

  Here, attention is paid to the heat transfer tube disassembly work in the heat exchanger disassembly work.

  18 to 21 are diagrams schematically showing a conventional heat transfer tube disassembling process.

  As shown in FIGS. 18 to 20, the plurality of heat transfer tubes 70 bent into a U-shape are first an arc-shaped partial tube 71 cut by an arc-shaped portion at a free end, a tube plate 72, or each support plate. A relatively long partial tube 74 corresponding to a portion between the tube plate 72 and the support plate 73 cut at the nearest portion of 73, or a portion between the support plates 73, and the tube plate 72 or the support plate 73 A relatively short partial tube 75 corresponding to the inserted portion is cut.

  Next, as shown in FIG. 21, the short partial tube 75 of the heat transfer tube 70 is removed from the tube plate 72 or the support plate 73. Since the heat transfer tube 70 and the tube plate 72 are fixed by partially expanding the heat transfer tube 70, considerable heat removal force is required. Although the heat transfer tube 70 and the support plate 73 have a gap when they are newly manufactured, the gap is blocked by the adhesion and corrosion of the scale due to aging, and a considerable extubation force is required. On the other hand, the tube plate 72 and the support plate 73 are subdivided.

  In a conventional tube removal tool used for removal, an engagement member provided with a plurality of serrated blades (collets) on the outer peripheral portion is inserted into the heat transfer tube 70, and the engagement member is expanded inside the heat transfer tube 70. Then, the collet bites into and engages with the inner surface of the heat transfer tube 70, and the extraction force is transmitted to the heat transfer tube. The engaging member is provided at the shaft core portion and is expanded by a rod having a tapered portion.

  Since the conventional tube removal tool is configured in a structural manner in which an engaging member or a lot needs to be inserted into the heat transfer tube 70, it is difficult to ensure strength with respect to the heat transfer tube 70, and sufficient tube removal for the heat transfer tube is possible. It was also difficult to convey power. Specifically, in the extruding operation of about 4400 heat transfer tubes 70, a situation occurs in which the rod breaks during about 10 extruding operations at most, causing fine burrs inside the heat transfer tube 70, resulting in In addition, the heat transfer tube 70 was required to be shredded. Since burrs and fine fragments generated in such tube extraction work are difficult to decontaminate, they must be drum-packed and disposed of.

  Next, the long partial tube 74 of the heat transfer tube 70, the short partial tube 75 after removal, and the thin pieces 76 and 77 of the tube plate 72 and the support plate 73 are decontaminated. At this time, the free end portions of the long partial tube 74 and the short partial tube 75 of the heat transfer tube 70 are deformed flat or burrs as the heat transfer tube 70 is cut. In such a state, since the inner peripheral surface of the heat transfer tube 70 cannot be sufficiently decontaminated, the ring-shaped pieces are further cut off from the free end portions of the long partial tube 74 and the short partial tube 75 of the heat transfer tube 70, Decontamination is performed after cutting the heat transfer tube (not shown) with little deformation and almost no burr. Since cutting debris and small pieces generated in the dismantling operation of the heat transfer tube 70 are difficult to decontaminate, they are packed in drums and must be disposed of.

  Increased waste from the removed heat exchanger generates large amounts of drum canned waste. Processing costs such as storage and burying of this large amount of drum canned waste are easily predicted to become enormous. The burrs and fine fragments generated in the heat transfer tube extraction operation, and the cutting waste and small pieces generated in the decontamination operation cause further increase in drum canned waste. Therefore, there is a demand for measures to reduce the amount of drum canned waste generated.

  In particular, if the heat transfer tube can be sufficiently decontaminated, it can be handled outside the management area, and the amount of drum canned waste generated can be greatly reduced. For this reason, the deformation | transformation of a heat exchanger tube is suppressed and the tube extraction tool and tube extraction method which can be extracted without cut | disconnecting finely are needed.

  Further, about 4400 heat transfer tubes are provided per heat exchanger, and the time required for the dismantling work is enormous, which costs a lot of money. Furthermore, due to partial refurbishment of the heat exchanger, a part of the heat transfer tube may be replaced, and the frequency of the heat transfer tube extraction work tends to increase. Therefore, there is a need for a tube extraction tool and a tube extraction method that can efficiently extract and remove a heat transfer tube.

  The present invention relates to a tube-extracting jig that can be efficiently removed without chopping the heat-transfer tube as much as possible from a structure such as a heat exchanger having a heat-transfer tube and a holding plate that holds the heat-transfer tube. Proposal of extubation method.

  In order to solve the above-described problems, the tube extruding jig of the present invention includes a cylindrical body portion in which a part of the circumference is notched in the axial direction, and a pair of flange portions formed at the notched end portions of the cylindrical body portion. And a plurality of biting protrusions provided to protrude from the inner periphery of the cylindrical body part, and a fastening groove in which the hook part can be freely fitted and removed, and the hook part is inserted into the fastening groove. And a fastening member for bringing the cut-out end portions of the cylindrical body portions closer to each other.

  Further, the tube extraction method of the present invention includes a heat transfer tube, and a holding plate that is appropriately disposed in the longitudinal axis direction of the heat transfer tube and has a hole through which the heat transfer tube is inserted. In the tube-extracting method for extracting and removing, a cylindrical body part in which a part of the circumference is cut off in the axial direction, a pair of flange parts formed at a cut-out end part of the cylindrical body part, and an inner circumference of the cylindrical body part A jig preparing step for preparing a tube-extracting jig comprising: a plurality of engagement protrusions projectingly provided; and a fastening member having a fastening groove into which the collar part can be freely fitted and removed; A part is inserted through the outer periphery of the heat transfer tube, the fastening member is attached to the flange, the notch ends of the cylindrical body part are brought close to each other, and the biting protrusion is bitten into the heat transfer tube, A jig mounting step of mounting the tube extracting jig on the heat transfer tube, and pulling the tube extracting jig mounted on the heat transfer tube and holding the tube Characterized in that and a pull-out step for pulling out the heat transfer tubes from.

  According to the present invention, an extubation treatment that can be efficiently removed without chopping the heat transfer tube as much as possible from a structure such as a heat exchanger including a heat transfer tube and a holding plate that holds the heat transfer tube. Can provide tools and extubation methods.

Sectional drawing which showed the feed water heater as an example of the structure where the extubation jig | tool and the extubation method which concern on embodiment of this invention are used. The front view which showed the extubation jig | tool which concerns on embodiment of this invention. The top view which showed the cylinder part of the extubation jig which concerns on embodiment of this invention. The side view which showed the cylinder part of the extubation jig which concerns on embodiment of this invention. The rear view which showed the cylinder part of the extubation jig which concerns on embodiment of this invention. The front view which showed the fastening member of the tube extraction jig which concerns on embodiment of this invention. The bottom view which showed the fastening member of the extubation jig which concerns on embodiment of this invention. The figure which showed the biting protrusion part of the extubation jig | tool which concerns on embodiment of this invention. The figure which showed the biting protrusion part of the extubation jig | tool which concerns on embodiment of this invention. The figure which shows the state which mounted | wore the heat exchanger tube with the tube extracting jig which concerns on embodiment of this invention. The flowchart which showed the extubation method in embodiment of this invention. The figure which showed the dismantling operation | work of the feed water heater using the tube extraction method in embodiment of this invention. The figure which showed the dismantling operation | work of the feed water heater using the tube extraction method in embodiment of this invention. The figure which showed the dismantling operation | work of the feed water heater using the tube extraction method in embodiment of this invention. The figure which showed the dismantling operation | work of the heat exchanger tube bundle using the tube extraction method in embodiment of this invention. The figure which showed the dismantling operation | work of the heat exchanger tube bundle using the tube extraction method in embodiment of this invention. The figure which showed the dismantling operation | work of the heat exchanger tube bundle using the tube extraction method in embodiment of this invention. The figure which showed the conventional heat exchanger tube disassembly process roughly. The figure which showed the conventional heat exchanger tube disassembly process roughly. The figure which showed the conventional heat exchanger tube disassembly process roughly. The figure which showed the conventional heat exchanger tube disassembly process roughly.

  Hereinafter, embodiments of a tube removal jig and tube extraction method according to the present invention will be described with reference to FIGS. In addition, the feed water heater provided in a nuclear power plant is demonstrated as an example of the structure where the extubation jig | tool and the extubation method which concern on this invention are used.

  FIG. 1 is a cross-sectional view illustrating a feed water heater as an example of a structure in which a tube extraction jig and a tube extraction method according to an embodiment of the present invention are used.

  As shown in FIG. 1, the feed water heater 1 is formed in a substantially cylindrical shape. The feed water heater 1 is disposed on the floor 2 of the nuclear power plant. The longitudinal axis of the feed water heater 1 is oriented substantially parallel to the floor surface 2. The feed water heater 1 includes a cylindrical main body cylinder 4 having one end opened, a tube plate 5 provided in the opening of the main body cylinder 4, and a water chamber cylinder 6 connected to the main body cylinder 4 with the tube plate 5 interposed therebetween. And comprising. Moreover, the fixed leg 8 and the legs 9 and 10 with a wheel are provided in the floor 2 side of the feed water heater 1, ie, the downward direction.

  A heat transfer tube bundle 13 composed of a plurality of heat transfer tubes 12 bent in a U shape is accommodated in the main body body 4. A steam inlet 14 is formed above the main body cylinder 4. A drain outlet 15 is formed below the main body barrel 4. Further, a body escape valve seat 17, a body air vent 18 and the like are formed in the main body body 4. The other end of the main body barrel 4 is closed by a body end plate 20.

  Each heat transfer tube 12 is held by a support plate 21 that is appropriately arranged in the longitudinal axis direction of the heat transfer tube bundle 13. A gap is provided between the heat transfer tube 12 and the support plate 21 to prevent generation of thermal stress.

  The interior of the water chamber barrel 6 is partitioned into two spaces 23 a and 23 b by the partition plate 22. The lower space 23 a on the side close to the floor surface 2 communicates with a water supply inlet 25 formed below the water chamber body 6. The upper space 23 b far from the floor surface 2 is communicated with a water supply outlet 26 formed above the water chamber body 6.

  The inlet side end of each heat transfer tube 12 penetrates through the tube plate 5 and communicates with the water chamber trunk lower space 23a. On the other hand, the outlet side end of the heat transfer tube 12 passes through the tube plate 5 and communicates with the water chamber trunk upper space 23b.

  A tube pulling jig according to this embodiment will be described.

  FIG. 2 is a front view showing a tube extruding jig according to an embodiment of the present invention.

  FIG. 3 to FIG. 5 are views showing a cylindrical body part of the extubation jig according to the embodiment of the present invention. FIG. 3 is a plan view showing the cylindrical body part, FIG. 4 is a side view showing the cylindrical body part, and FIG. 5 is a rear view showing the cylindrical body part.

  6 to 7 are views showing a fastening member of the tube extracting jig according to the embodiment of the present invention. FIG. 6 is a front view showing the fastening member, and FIG. 7 is a bottom view showing the fastening member.

  As shown in FIGS. 2 to 7, the tube removal jig 30 includes a holder portion 31 and a fastening member 32. The tube extraction jig 30 transmits a tube extraction force generated by a tube extraction tool (not shown) to the heat transfer tube 12, and is a component of the tube extraction tool.

  The holder part 31 is formed using steel materials, such as hot-rolled steel materials, for example. The holder part 31 includes a cylindrical body part 34, a pair of flange parts 35 a and 35 b, and a plurality of biting protrusion parts 36.

  The cylindrical part 34 is formed in a substantially cylindrical shape in which a part of the circumference is cut out in the longitudinal axis direction. A pair of flange portions 35a and 35b are formed at the cut-out end portions 34a and 34b of the cylindrical body portion 34. The flange portions 35a, 35b are formed so as to protrude from the respective cutout end portions 34a, 34b in the radially outward direction of the cylindrical body portion 34 and to spread in the circumferential direction. That is, the holder part 31 is formed in a substantially cross-sectional Ω shape. A plurality of biting protrusions 36 are provided on the inner periphery of the cylindrical body 34 so as to protrude toward the center thereof.

  The plurality of biting projections 36 are provided in a plurality of rows, for example, four rows, with a pair of biting projections 36a and 36b facing each other in one row. A tube mounting tool 37 is provided at one end of the cylindrical body portion 34 to which a tube extracting tool is connected and a tube extracting force is input.

  The flange portions 35a, 35b are tapered portions 35e formed so that the distance W1 (width W1 in FIG. 3) between the flange tips 35c, 35d decreases as the free end portion 34c of the cylindrical body portion 34 approaches. 35f (the minimum width W2 in FIG. 3).

  The fastening member 32 is formed into a C-shaped cross section using, for example, a steel material such as a carbon steel material. The fastening member 32 has a fastening groove 39 into which the flange portions 35a and 35b can be fitted and removed. When the flange portions 35a and 35b are fitted into the fastening groove 39, the fastening member 32 brings the cut-out end portions 34a and 34b of the cylindrical body portion 34 closer to each other.

  The minimum opening width W3 (width W3 in FIG. 7) of the groove opening 40 of the fastening groove 39 is between the root portions 35g and 35h of the flange portions 35a and 35b in a free state in which the fastening member 32 is detached from the flange portions 35a and 35b. Is configured to be narrower than the distance W4 (width W4 in FIG. 3). In other words, the distance W4 between the root portions 35g and 35h of the flange portions 35a and 35b is configured to be larger than the minimum opening width W3 of the groove port 40 of the fastening groove 39 in the free state of the cylindrical body portion 34.

  The fastening member 32 has tapered portions 41a and 41b in which the opening width of the groove 40 is increased as the free end portion is approached. The maximum opening width W5 (width W5 in FIG. 7) of the taper portions 41a and 41b is wider than the distance W4 (width W4 in FIG. 3) between the root portions 35g and 35h of the flange portions 35a and 35b in the free state. Composed.

  When using the tube extraction jig 30, the flange portions 35a, 35b of the holder portion 31 are fitted into the fastening grooves 39 of the fastening member 32, and the fastening member 32 is moved in the axial direction of the cylindrical body portion 34, so that the flange portion 35a. , 35b (solid arrow in FIG. 3). Accordingly, the cylindrical portion 34 is reduced in diameter from the diameter D1 in the free state (diameter D1 in FIG. 5) to the diameter D2 in the fastening state (diameter D2 in FIG. 2). At this time, the root portions 35g and 35h of the flange portions 35a and 35b are guided to the groove 40 while sliding on the tapered portions 41a and 41b.

  FIG. 8 and FIG. 9 are diagrams showing the biting protrusions of the extubation jig according to the embodiment of the present invention.

  As shown in FIGS. 8 and 9, the biting projection 36 is formed in a male screw shape. The occlusal projection 36 has an end portion that has a projection 43 that has a conical projection 43 or an occlusion projection 36B that has a concavity 44 that has a conical recess. Configured as follows. The biting protrusion 36 has a male screw 45 and is fastened to a female screw (not shown) formed on the cylindrical portion 34 of the holder portion 31. The biting protrusion 36 can adjust the amount of protrusion in the cylindrical portion 34 by adjusting the tightening amount. The biting protrusion 36 may be fixed by caulking the cylindrical body 34 or the like, and fixed to an appropriate protruding length.

  Note that the biting protrusion 36B having the recessed portion 44 is more suitable in terms of chucking the heat transfer tube 12 than the biting protrusion 36A having the protrusion 43.

  FIG. 10 is a view showing a state in which the tube extracting jig according to the embodiment of the present invention is attached to the heat transfer tube.

  As shown in FIG. 10, when the tube extracting jig 30 is attached to any heat transfer tube 12 in the heat transfer tube bundle 13 of the feed water heater 1, the holder portion 31 is provided around the outer peripheral surface of the heat transfer tube 12. . Further, the fastening member 32 of the tube extracting jig 30 is disposed in a gap between the plurality of heat transfer tubes 12 arranged in a lattice shape or a zigzag shape. The biting protrusion 36 of the tube extracting jig 30 bites into the outer peripheral portion of the heat transfer tube 12 and is bitten. In this way, the tube extracting jig 30 is attached to the heat transfer tube 12.

  Next, a method for extracting the heat transfer tube 12 from the feed water heater 1 will be described.

  First, a method for disassembling the feed water heater 1 will be described.

  FIG. 11 is a flowchart showing the extubation method in the embodiment of the present invention.

  FIG. 12 to FIG. 14 are diagrams showing dismantling work of the feed water heater using the extubation method in the embodiment of the present invention.

  FIG. 15 to FIG. 17 are diagrams showing the disassembling work of the heat transfer tube bundle using the tube extraction method in the embodiment of the present invention.

  As shown in FIG. 11, in the tube extraction method according to the present embodiment, first, in step S1, the main body cylinder 4 and the water chamber cylinder 6 are separated from the feed water heater 1 (FIG. 12). Then, the tube plate 5, the heat transfer tube bundle 13 fixed to the tube plate 5, and the support plate 21 that holds the heat transfer tube bundle 13 are exposed. The tube plate 5, the heat transfer tube bundle 13, and the support plate 21 are held on the floor 2 by a temporary receiving base 48 that is appropriately arranged (FIG. 13).

  Thereafter, the disassembly work of the main body cylinder 4 and the water chamber cylinder 6 proceeds to step S2. The disassembly work of the tube plate 5, the heat transfer tube bundle 13, and the support plate 21 proceeds to step S4.

  Next, in step S2, the main body cylinder 4 and the water chamber cylinder 6 are cut into small pieces 49 and 50 (FIG. 14).

  Next, in step S3, the fine pieces 49 and 50 of the main body cylinder 4 and the water chamber cylinder 6 are individually decontaminated, and the fine pieces 49 and 50 that can be recycled according to the residual radioactivity and the non-recyclable pieces. Into small pieces 49 and 50. The small pieces 49 and 50 that cannot be recycled, and the cutting waste resulting from the cutting of the main body cylinder 4 and the water chamber cylinder 6 are used as radioactive waste as drum canned waste.

  Next, in step S4, it cut | disconnects by the arc-shaped part of the free end part of the heat exchanger tube 12 bent by the U-shape, and while cutting | disconnecting the arc-shaped partial pipe | tube 51, the heat exchanger tube 12 is cut | disconnected from the vicinity of the tube sheet 5 (FIG. 15). Then, the heat transfer tube 12 is divided into a relatively short partial tube 52 left on the tube plate 5 and a partial tube 53 occupying most of the straight tube portion of the heat transfer tube 12 bundled with the plurality of support plates 21. Is done.

  Next, in step S5, the tube extraction jig 30 and the tube extraction tool 55 are prepared.

  Next, in step S6, the extubation jig 30 is attached to one free end of the partial tube 53, for example, the terminal portion 53a from which the arc-shaped partial tube 51 is cut off. Specifically, the tubular portion 34 of the tube extracting jig 30 is inserted into the outer periphery of the terminal portion 53 a of the partial tube 53, the fastening member 32 is attached to the flange portions 35 a and 35 b, and the notched end of the tubular portion 34 is mounted. By bringing the portions 34a and 34b closer to each other, the diameter D1 of the cylindrical portion 34 is reduced, the biting projection 36 is bitten into the partial tube 53, and the extubation jig 30 is attached to the partial tube 53 ( FIG. 10). At this time, the terminal portion 53a of the partial tube 53 is deformed into a flat shape or has a burr as the heat transfer tube 12 is cut. In such a state, since the inner peripheral surface of the heat transfer tube 12 cannot be sufficiently decontaminated, a ring-shaped small piece is further cut off from the end portion 53a of the partial tube 53, and the portion is less deformed and almost free of burrs. The tube extraction jig 30 may be attached to the tube 53. Further, the tool attachment port 37 of the tube removal jig 30 is connected to the tube removal tool 55.

  Next, in step S7, the tube extraction jig 30 is pulled with the tube extraction tool 55, and the partial tubes 53 are extracted from the plurality of support plates 21 at once (FIG. 16). The tube extraction work in step S6 and step S7 is repeated for all the partial tubes 53.

  Next, in step S <b> 8, the tube removal jig 30 is attached to the terminal portion 52 a of the partial tube 52. Specifically, the tubular portion 34 of the tube extraction jig 30 is inserted into the outer periphery of the terminal portion 52 a of the partial tube 52, the fastening member 32 is attached to the flange portions 35 a and 35 b, and the notched end of the tubular portion 34 is mounted. By bringing the portions 34 a and 34 b closer to each other, the diameter D 1 of the cylindrical body portion 34 is reduced, the biting protrusion 36 is bitten into the partial tube 52, and the tube extraction jig 30 is attached to the partial tube 52. At this time, the terminal portion 52a of the partial tube 52 is deformed into a flat shape or burrs as the heat transfer tube 12 is cut. In such a state, since the inner peripheral surface of the heat transfer tube 12 cannot be sufficiently decontaminated, a ring-shaped small piece is further cut off from the end portion 52a of the partial tube 52, and the portion is less deformed and almost free of burrs. The tube removal jig 30 may be attached to the tube 52. Further, the tool attachment port 37 of the tube removal jig 30 is connected to the tube removal tool 55.

  Next, in step S <b> 9, the tube removal jig 30 is pulled with the tube removal tool 55, and the partial tube 52 is removed from the tube sheet 5. The tube extraction work in steps S8 and S9 is repeated for all the partial tubes 52.

  Next, in step S10, the tube plate 5 and the support plate 21 are cut into small pieces 56 and 57 (FIG. 17).

  Next, in step S11, the thin pieces 56 and 57, the partial tube 52, the partial tube 53, and the arc-shaped partial tube 51 are individually decontaminated. At this time, the free end portion of the partial tube 53 located on the tube plate 5 side and the free end portion of the arc-shaped partial tube 51 are deformed flat or burr due to the cutting of the heat transfer tube 12. It is. In such a state, since the inner peripheral surface of the heat transfer tube 12 cannot be sufficiently decontaminated, the ring-shaped small pieces are further cut off from the free ends of the partial tube 52, the partial tube 53, and the arc-shaped partial tube 51 to reduce deformation. Then, after cutting with almost no burrs, heat transfer tubes (not shown) are used for decontamination. After decontamination, it is classified into those that can be recycled and those that cannot be recycled, depending on the residual radioactivity. Non-recyclable items, cutting scraps resulting from cutting of the tube plate 5 and the support plate 21, cutting scraps resulting from cutting the heat transfer tube 12, and ring-shaped pieces cut out from the heat transfer tube 12 are radioactive waste. As drum waste.

  According to the tube extracting jig 30 and the tube extracting method according to the present embodiment, when the structure such as the heat exchanger having the heat transfer tube 12 such as the feed water heater 1 is disassembled, the free end side of the tube sheet 5 is used. The heat transfer tube 12 can be removed while holding the outer peripheral portion of the tube firmly with the tube extraction jig 30 and maintaining a long state as much as possible.

  Therefore, according to the tube extraction jig 30, by grasping the outer peripheral portion of the heat transfer tube 12, it is possible to ensure a tube extraction force comparable to the tensile strength of the heat transfer tube 12 without causing damage in the heat transfer tube 12. Can communicate. Moreover, according to the exfoliation jig 30 and the exfoliation method, the generation amount of cutting waste, burrs, and ring-shaped pieces in the extruding of the heat transfer tube 12 can be suppressed to a very small amount. Specifically, unlike the conventional tube extraction method using the tube extraction tool, it is not necessary to cut the heat transfer tube 12 in the vicinity of each support plate 21, and the amount of cutting scraps and ring-shaped small pieces generated at this position can be reduced. It can be suppressed to a very small amount. This makes it possible to reliably reduce the amount of drum canned waste generated.

  Moreover, according to the tube extraction jig 30 according to the present embodiment, when removing any heat transfer tube 12 of the heat transfer tube bundle 13, the presence or absence of the adjacent heat transfer tubes 12 arranged in a lattice shape or a staggered shape is determined. It is possible to easily and smoothly attach the tube extracting jig 30 and remove the heat transfer tube 12 without being affected.

  Therefore, when the structure such as the heat exchanger having the heat transfer tube 12 such as the feed water heater 1 is dismantled, the work period of the dismantling work can be shortened. Moreover, when exchanging a part of the heat transfer tube 12 for partial repair of a structure such as a heat exchanger, the target heat transfer tube 12 can be efficiently removed.

  Therefore, according to the tube extraction jig 30 and the tube extraction method according to the present embodiment, the heat transfer tube 12 is efficiently removed from the structure such as a heat exchanger provided with the heat transfer tube 12 as much as possible. it can.

DESCRIPTION OF SYMBOLS 1 Feed water heater 2 Floor surface 4 Body trunk 5 Tube plate 6 Water chamber trunk 8 Fixed leg 9, 10 Wheeled leg 12 Heat transfer pipe 13 Heat transfer pipe bundle 14 Steam inlet 15 Drain outlet 17 Body relief valve seat 18 Body air vent 20 Body end plate 21 Support plate 22 Partition plate 23a Lower space 23b Upper space 25 Water supply inlet 26 Water supply outlet 30 Pipe extraction jig 31 Holder part 32 Fastening member 34 Cylindrical part 34a, 34b End part 34c Free end part 35a, 35b 35c, 35d Tip 35e, 35f Taper portion 35g, 35h Root portion 36, 36A, 36B, 36a, 36b Bite projection 37 Tool attachment port 39 Fastening groove 40 Groove port 41a, 41b Taper portion 43 Projection portion 44 Concave portion 45 Male thread 48 Temporary pedestal 49, 50 Fine segment 51 Arc-shaped partial tube 52, 53 Partial tube 52a, 53a Terminal portion 55 Extubation tool 56, 57 Fine segment 70 1 Arc-shaped partial tube 72 Tube plate 73 Support plates 74, 75 Partial tubes 76, 77 Fine fragments

Claims (6)

A cylindrical body part that is partially cut off in the axial direction;
A pair of eaves formed at the notched end of the cylindrical body;
A plurality of biting protrusions provided to protrude on the inner periphery of the cylindrical body part;
A fastening member having a fastening groove that allows the hook part to be fitted and removed, and a fastening member that brings the notch ends of the cylindrical body part close to each other when the hook part is fitted into the fastening groove. Extubation jig. The distance between the base parts of the said collar part is comprised larger than the minimum opening width of the groove opening of the said fastening groove in the state from which the said fastening member was detach | leaved from the said collar part. The tube extruding jig described. The tube-extracting jig according to claim 1, wherein the groove opening has a tapered portion whose opening width is increased as the free end portion of the fastening member is approached. The tube extraction jig according to any one of claims 1 to 3, wherein a tip of the biting projection is recessed in a conical shape. The tube-extracting jig according to any one of claims 1 to 4, wherein the fastening member is moved in an axial direction of the cylindrical body portion and attached to the cylindrical body portion. A heat transfer tube,
In a tube extraction method for removing the heat transfer tube from a structure, which is appropriately disposed in the longitudinal axis direction of the heat transfer tube, and a holding plate having a hole through which the heat transfer tube is inserted,
A cylindrical body part that is partially cut off in the axial direction;
A pair of eaves formed at the notched end of the cylindrical body;
A plurality of biting protrusions provided to protrude on the inner periphery of the cylindrical body part;
A jig preparing step of preparing a tube-extracting jig provided with a fastening member having a fastening groove in which the collar portion is freely detachable;
The cylindrical body portion is inserted into the outer periphery of the heat transfer tube, the fastening member is attached to the flange portion, the notch end portions of the cylindrical body portion are brought close to each other, and the biting protrusion is attached to the heat transfer tube A jig mounting step for biting and mounting the extubation jig on the heat transfer tube;
A tube-extracting method comprising: an extraction step of pulling the tube-extracting jig attached to the heat-transfer tube and extracting the heat-transfer tube from the holding plate.

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