Scale removal unit

Abstract

The present invention provides a scale removal unit that can remove scale adhering to the outer surface of a pipe while suppressing increases in manufacturing costs and weight. [Solution] The scale removal unit 1 comprises a gripping section 12, a long section 11, a removal head 13, and a wire 14. The long section 11 is made of a single metal plate that is flexible in the thickness direction. The removal head 13 is attached to the tip 11b of the long section 11 and consists of multiple head components connected together. Each of the multiple head components has a projection. When the operator pulls the handle 122, the wire 14 is pulled towards the gripping section 12, causing the removal head 13 to be in a holding state where the tips of the projections locally contact the scale adhering to the outer surface of the target pipe. When the operator does not pull the handle 122, the removal head 13 is released and can pass through the gaps between pipes.

Description

Technical Field

[0001] The present invention relates to a scale removal unit.

Background Art

[0002] For a tube bundle provided in a boiler or the like, wall thickness measurement may be performed by ultrasonic waves. The wall thickness measurement by ultrasonic waves is performed by bringing an ultrasonic probe into contact with the outer peripheral surface of the tube to be measured.

[0003] By the way, in a tube bundle such as a boiler, scale may adhere to the outer peripheral surface. Scale is formed by adhesion and deposition of combustion ash, dust, etc. on the outer peripheral surface. Scale has an irregular shape and often does not allow ultrasonic waves to pass through. Therefore, when attempting to perform wall thickness measurement by ultrasonic waves, it is necessary to remove the scale at the location on the outer peripheral surface of the tube to be measured where wall thickness measurement is to be performed.

[0004] Patent Document 1 discloses a boiler tube cleaning tool for removing scale using a jet hammer. As shown in FIGS. 11(a) to (c), the boiler tube cleaning tool (hereinafter simply referred to as "tool") 900 disclosed in Patent Document 1 includes an arm 919, a support guide 901, and a curved plate 902. The arm 919 has a cylindrical shape. The support guide 901 is formed by connecting a plurality of connecting plates 9011 to 9017 in a chain shape. The support guide 901 is fixed to a support portion 935 inside the arm 919 and is configured to be able to project and retract from the opening of the arm 919. The projection and retraction of the support guide 901 from the opening of the arm 919 is achieved by moving the support portion 935 by a motor 934 and a ball screw 933 provided inside the arm 919.

[0005] The curved plate 902 has an arc shape when viewed from the side and is rotatably supported on the connecting plate 9011 at the tip of the support guide 901. A jet hammer 903 is fixed to the inner part of the arc of the curved plate 902. A gear 905 is fixed to the connection point between the curved plate 902 and the connecting plate 9011. A chain 906 is connected to the gear 905 so as to mesh with it. Wires 907 are connected to both ends of the chain 906. The wires 907 are connected to a gear housed in the arm 919 and are unwound / retracted by a motor 930 that rotates the gear. The curved plate 902 can change its orientation between a state in which it overlaps the connecting plate 9011 shown in Figure 11(b) and a state in which it is pulled out from the connecting plate 9011 shown in Figure 11(a) and the jet hammer 903 is in contact with or close to the outer surface of the boiler tube 950, by driving the chain 906 via the wire 907 driven by the motor 930.

[0006] Furthermore, wire 917 is fixed to the connecting plate 9011 at the inner part 9011b of the arc, and wire 918 is fixed to the outer part 9011a of the arc. The other end of wire 917 is connected to a drum pivotally supported within the support part 935, and is unwound / retracted from the drum when the drum is rotated by motor 923. The other end of wire 918 is connected to a drum pivotally supported within the support part 935, and is unwound / retracted from the drum when the drum is rotated by motor 926.

[0007] The tool 900 disclosed in Patent Document 1 can remove scale from a predetermined location on the boiler tube 950 by driving four motors 923, 926, 930, and 934, thereby changing the state from that shown in Figure 11(b) to that shown in Figures 11(a) and 11(c). [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Official Gazette No. 03-56091 [Overview of the project] [Problems that the invention aims to solve]

[0009] However, the tool 900 disclosed in Patent Document 1 above has four motors 923, 926, 930, and 934 in the arm 919, which inevitably increases manufacturing costs. In addition, since the tool 900 has four motors 923, 926, 930, and 934 to change the position and orientation of the curved plate 902, an increase in weight is unavoidable, raising concerns about reduced workability.

[0010] The present invention aims to solve the above-mentioned problems and provides a scale removal unit that can remove scale adhering to the outer surface of a pipe while suppressing increases in manufacturing costs and weight. [Means for solving the problem]

[0011] A scale removal unit according to one aspect of the present invention is a unit for removing scale attached to a target pipe among a group of pipes in which a number of pipes are arranged with gaps between them. The scale removal unit according to this aspect comprises a long section, a removal head, an operating section, and a connecting section. The long section is a long, elongated part with a thickness that allows it to pass through the gaps. The removal head is attached to the tip of the long section and is provided on a part of its outer surface, with a pointed projection at its tip. The operating section is located outside the group of pipes and is for an operator to operate the removal head. The connecting section is made of a flexible linear or membrane-like elongated member that extends along the long section and mechanically connects the removal head and the operating section.

[0012] In the scale removal unit according to this embodiment, the removal head is configured to be changeable between a holding state and a release state. The holding state is a state in which, when the connecting portion is pulled along the elongated portion toward the base end opposite to the tip portion by the operator's operation of the operating unit, the head is held in a curved position such that the tip of the projection contacts at least a portion of the scale adhering to the outer surface of the target pipe. The release state is a state in which the head can pass through the gap when the operator does not operate the operating unit.

[0013] In the scale removal unit according to the above embodiment, the operator can change the state of the removal head from a released state to a held state by operating the operating unit. The connecting part is a linear or membrane-like member that mechanically connects the removal head and the operating unit. Therefore, the above scale removal unit can have a simpler configuration than a tool that has four motors 923, 926, 930, and 934 inside the arm 919 for changing the state of the curved plate 902, as in the above Patent Document 1.

[0014] Furthermore, in the scale removal unit according to the above embodiment, since the removal head has a projection, scale can be efficiently removed by locally contacting the tip of the projection with the scale adhering to the target pipe and rubbing it. Note that there may be one or more projections, and they may be a series of fine projections like a file.

[0015] Therefore, the above-mentioned scale removal unit is a unit that can remove scale adhering to a target pipe while suppressing the increase in manufacturing cost and weight compared to the tool disclosed in Patent Document 1.

[0016] In boilers and the like, the gaps between tubes can be relatively wide or relatively narrow. To get the removal head through such a tube group to the target tube, if the gaps are relatively wide, it may be possible to insert the removal head while it is still in a holding position. However, in cases where the gaps between tubes are relatively narrow, such as in a staggered arrangement of tubes, the removal head cannot be inserted while in a holding position. Releasing the head allows for smooth insertion without it getting caught on intermediate tubes. Thus, with the scale removal unit according to the above embodiment, the removal head can be smoothly inserted to the target tube even when the gaps between tubes in a tube group are narrow. Moreover, since the connecting part is linear or membrane-shaped, the connecting part can pass through along with the long part even when the gaps are narrow.

[0017] In the scale removal unit according to the above embodiment, the removal head may have a plurality of head components connected in series by being pivotally supported by each other at the radially outer portion of the curved position. In this case, when the release state is reached, at least some of the head components may be spaced apart from adjacent head components except for the pivotally supported portion. Furthermore, at least some of the head components may be configured to curve until the spaced portions come into contact with each other as the state changes from the release state to the holding state.

[0018] In the scale removal unit according to the above embodiment, the removal head is composed of multiple head components that are pivotally supported by each other. At least some of the multiple head components are curved by pulling the connecting portion when the operating part is operated, until the separated portions of adjacent head components come into contact. Therefore, in the above scale removal unit, by making the radius of curvature of the curve when adjacent head components come into contact (when taking a curved position) smaller than the outer diameter of the target pipe, it is possible to reliably bring the projection of the removal head into contact with the scale attached to the target pipe. Thus, the above scale removal unit enables efficient scale removal with a simple configuration.

[0019] In the scale removal unit according to the above embodiment, each of the plurality of head components may be provided with a connecting guide having a pivoted support portion that is pivotally supported for connection with an adjacent head component, and a wall portion having a predetermined height in a direction perpendicular to the connection direction with the adjacent head component. In this case, the sides of the wall portion on both sides in the connection direction may have inclined surfaces formed thereon, such that the width of the wall portion in the connection direction gradually decreases as it moves away from the pivoted support portion in the direction perpendicular to it. Furthermore, the inclined surfaces may be configured to abut the inclined surfaces of the adjacent head components when in the holding state.

[0020] In the scale removal unit according to the above embodiment, each head component is equipped with a connecting guide having a slanted portion on its wall, and the slanted portions are formed so that when the removal head is in a holding state, the slanted portions of adjacent head components come into contact with each other. Therefore, in the above scale removal unit, the curvature of the curvature when the removal head is in a bent position is defined by the inclination angle and size of the slanted portion. In other words, in the scale removal unit, the curvature of the curvature of the removal head can be defined by defining the inclination angle and size of the slanted portion. Thus, in the above scale removal unit, it is possible to bend the removal head with a curvature corresponding to the outer diameter of the target pipe.

[0021] In the scale removal unit according to the above embodiment, the furthest head component, which is the head component furthest from the elongated portion in the connecting direction, may have a fixing portion to which the connecting portion is fixed. In addition, the intermediate head components, which are the head components other than the furthest head component, may have a through hole through which the connecting portion is movably inserted in the portion that is radially inward of the curved posture.

[0022] In the scale removal unit according to the above embodiment, the furthest head component has a fixing part to which the connecting part is fixed, and the other head components (intermediate head components) have through holes through which the connecting part is inserted. Therefore, when the connecting part is pulled by the operator's operation of the control unit, adjacent head components rotate with the radially outer part of the curve, which is pivotally supported, as the pivot point until adjacent components on the radially inner side of the curve come into contact with each other. In this way, the above scale removal unit can change the state of the removal head from a released state to a held state with a simple configuration that does not include a motor as described in Patent Document 1. Therefore, the above scale removal unit can efficiently remove scale attached to a target pipe by guiding the removal head along the scale while suppressing increases in manufacturing cost and weight compared to the tool disclosed in Patent Document 1.

[0023] In the scale removal unit according to the above embodiment, the removal head may have a plurality of head components connected in series by being pivotally supported by each other at the portion that is radially outward of the curved position. In this case, the projection may be provided on at least one of the plurality of head components toward the radially inward direction of the curved position.

[0024] In the scale removal unit according to the above aspect, in at least one head component, the protrusion has protruded toward the radially inner side in the curved posture, so that the tip of the protrusion abuts against the scale by holding the removal head. Therefore, even if the scale attached to the target pipe is hard, by holding the removal head, the tip of the protrusion can be locally abutted against the scale, and scale removal can be performed with high efficiency.

[0025] In the scale removal unit according to the above aspect, the removal head may have a vibration generation source capable of applying vibration to the protrusion.

[0026] In the scale removal unit according to the above aspect, the removal head has a vibration generation source, and the vibration generation source can apply vibration to the protrusion. Therefore, by locally abutting the tip of the protrusion against the scale attached to the target pipe and applying vibration, scale removal can be performed more efficiently.

[0027] Note that one vibration generation source can be provided for the removal head, but a plurality of vibration generation sources can also be provided in a dispersed manner for the removal head. When a plurality of vibration generation sources are provided in a dispersed manner like this, the size of each vibration generation source can be kept small, and the size increase of the removal head can be suppressed. Therefore, if such a configuration is adopted, it can be made easier for the removal head to pass between the intermediate pipes and reach the target pipe.

[0028] In the scale removal unit according to the above aspect, the long portion may be composed of a single plate material having flexibility in the thickness direction.

[0029] In the scale removal unit according to the above embodiment, the elongated section is made of a single plate material that is flexible in the thickness direction, so that as the removal head is inserted to the position of the target pipe, the elongated section can use its flexibility to avoid pipes in the middle. For this reason, in the scale removal unit according to the above embodiment, even when inserting the removal head into a group of pipes arranged in a grid pattern, as well as a group of pipes arranged in a staggered pattern, the elongated section can use its flexibility to prevent it from getting caught on pipes in the middle.

[0030] In the scale removal unit according to the above embodiment, the elongated portion may be composed of a plurality of plate materials arranged in series along the longitudinal direction of the elongated portion and connected to one another.

[0031] In the scale removal unit according to the above embodiment, the elongated section is made up of multiple interconnected plate materials, so that when the removal head is inserted to the position of the target pipe, the elongated section can move around pipes in the middle due to its flexibility. Therefore, in the scale removal unit according to the above embodiment, the removal head can reach the target pipe not only in groups of pipes arranged in a grid pattern, but also in groups of pipes arranged in a staggered pattern.

[0032] In the scale removal unit according to the above embodiment, each of the plurality of plate materials may have a through hole that allows the connecting portion to be inserted in a movable manner. In this case, the elongated portion may be configured to change between a restrained state and a flexible state depending on whether or not the operator operates the control unit. The restrained state is a state in which the adjacent plate materials come into contact with each other and their posture is restrained when the connecting portion is pulled toward the base end side by the operator's operation of the control unit. The flexible state is a state in which the posture is not restrained because no contact stress acts between the adjacent plate materials when the operator does not operate the control unit.

[0033] In the scale removal unit according to the above embodiment, multiple plate materials are connected by connecting parts. Therefore, compared to the case where the plate materials are connected by a component other than the connecting parts, the number of parts constituting the unit can be reduced, which is effective in suppressing increases in manufacturing costs and weight.

[0034] Furthermore, in the scale removal unit according to the above embodiment, when the connecting part is pulled by the operator, the state of the removal head can be changed from a released state to a held state as described above, and the state of the long section can be changed from a flexible state to a constrained state. In other words, in the scale removal unit according to the above embodiment, both the state of the removal head and the state of the long section can be changed by a single operation of the operating part by the operator. Therefore, the above scale removal unit is effective in achieving high work efficiency. [Effects of the Invention]

[0035] The scale removal unit according to each of the above embodiments can remove scale adhering to the outer surface of a pipe while suppressing increases in manufacturing costs and weight. [Brief explanation of the drawing]

[0036] [Figure 1] This is a perspective view showing the configuration of the scale removal unit according to the first embodiment. [Figure 2] (a) is a side view showing a part of the elongated section and its surrounding structure, and (b) is a side view showing the flexibility of the elongated section. [Figure 3] This is a plan view showing the configuration of the removal head. [Figure 4] This is an exploded perspective view showing the configuration of one of the multiple head components that make up the removal head. [Figure 5] This is a perspective view showing the removal head in the released state. [Figure 6] This is a perspective view showing the removal head in the holding state. [Figure 7](a) is a diagram showing the state before the scale removal unit is inserted into the boiler, and (b) is a diagram showing the state during the insertion of the scale removal unit into the boiler. [Figure 8] (a) is a diagram showing the removal head reaching the target pipe, and (b) is a diagram showing the removal head in a holding position, positioned along the outer circumference of the target pipe. [Figure 9] This is a plan view showing the configuration of the scale removal unit according to the second embodiment. [Figure 10] (a) is a plan view showing the long section when it is in a flexible state, and (b) is a plan view showing the long section when it is in a contact state. [Figure 11] The diagram shows a conventional boiler tube cleaning tool, where (a) is a diagram showing the overall configuration, (b) is a diagram showing the curved plate overlapping with the connecting plate, and (c) is a diagram showing the curved plate and connecting plate wrapped around the outer circumference of the boiler tube. [Modes for carrying out the invention]

[0037] Embodiments of the present invention will be described below with reference to the drawings. The embodiments described below are illustrative examples of the present invention, and the present invention is not limited to the following embodiments except for its essential configuration.

[0038] [First Embodiment] The scale removal unit 1 according to the first embodiment will be described with reference to Figures 1 to 8.

[0039] As shown in Figures 7 and 8, the scale removal unit 1 according to this embodiment is a unit used to remove scale 502 adhering to a target pipe 501a, which is one of the many pipes 501 provided in a boiler 500 from which scale 502 is to be removed. Specifically, the scale removal unit 1 is a unit developed to remove scale 502 adhering to the outer surface 501b of the target pipe 501a before inspection, when inspecting the thinning of the target pipe 501a using ultrasound.

[0040] As shown in Figures 7(a) and (b), the boiler 500 is equipped with a group of tubes in which a large number of tubes 501 are arranged with gaps G between them. The large number of tubes 501 are arranged horizontally so that their tube axes are parallel to each other to form a group, and the horizontally arranged group is arranged to form multiple layers in the vertical direction. When the large number of tubes 501 is viewed from the vertical direction, the multiple layers are arranged such that tubes from the layers above and below exist in the gaps between tubes in any given layer. That is, when the large number of tubes 501 is viewed from each tube axis direction, the large number of tubes 501 are arranged in a staggered pattern. However, the scale removal unit 1 can target not only boilers 500 in which the large number of tubes 501 are arranged in a staggered pattern, but also boilers 500 in which the large number of tubes 501 are arranged in a grid pattern.

[0041] It has been found that in the boiler 500, the tube 501 is prone to thinning around the 45° downward angle on its outer surface 501b. Therefore, the scale removal unit 1 is configured to also remove the scale 502 that has adhered to the 45° downward angle on the outer surface 501b of the target tube 501a.

[0042] 1. Configuration of Scale Removal Unit 1 The scale removal unit 1 according to this embodiment can remove scale 502 attached to target pipes 501a, not only to pipes 501 located in the surface layer 500a of the boiler 500, but also to pipes 501 located in the deep layer 500b. For this reason, the scale removal unit 1 is inserted into the gaps between pipes 501 along the way so that it can reach the target pipes 501a located in the deep layer 500b of the boiler 500.

[0043] As shown in Figure 1, the scale removal unit 1 comprises a long section 11, a gripping section 12, and a removal head 13. The scale removal unit 1 further comprises a pair of wires (connecting sections) 14, a drive unit 20, a power cable 23, and a signal cable 24. The drive unit 20 consists of a motor driver 21 and a battery 22 connected by the power cable 23. The signal cable 24 connects the motor driver 21 and the removal head 13.

[0044] The elongated section 11, the gripping section 12, and the removal head 13 are connected to each other and constitute the unit body 10.

[0045] The gripping section 12 is configured to be gripped by an operator above (outside) the boiler 500. The gripping section 12 comprises a gripping body 121 and a handle (operating section) 122. The gripping body 121 has a rectangular annular external shape and has a long section 11 attached to it. The handle 122 has a rectangular annular external shape that is smaller in size than the gripping body 121 and is attached to the gripping body 121 in a manner that allows it to slide between the side of the gripping body 121 to which the long section 11 is attached (-X side) and the opposite side (+X side).

[0046] The elongated portion 11 has a strip-like external shape and is an elongated part that extends in the X direction from the base end 11a attached to the gripping portion 12 toward the tip end 11b. In this embodiment, the elongated portion 11 is made of a single plate made of a metal material, for example. As the material for forming the plate, for example, a stainless steel plate is used.

[0047] As shown in Figure 2(a), for example, when the elongated portion 11 is made of stainless steel plate, the elongated portion 11 has a thickness T of 1 mm or less, more specifically 0.3 mm or more and 0.8 mm or less. The elongated portion 11 is formed with the above thickness T, giving it flexibility in the thickness direction. This allows the elongated portion 11 to pass through the gaps between the tubes 501 in the boiler 500.

[0048] Furthermore, as shown in Figure 2(b), the scale removal unit 1 employs a long section 11 that is flexible in the thickness direction, which allows it to avoid the intermediate pipe 501 during insertion.

[0049] As shown in Figure 3, the removal head 13 is attached to the tip 11b of the elongated section 11. In this embodiment, the removal head 13 comprises a plurality (for example, nine) of head components 130 that are pivotally supported by each other. The removal head 13 is configured to change between a held state shown in Figure 6 and a released state shown in Figure 5, depending on whether or not the operator operates the handle 122. In other words, the released state is a state in which the plurality of head components 130 are arranged in a straight line, as shown in Figure 5. In contrast, the held state is a state in which the connection angle between adjacent head components 130 changes relative to the released state, causing the removal head 13 as a whole to be curved, as shown in Figure 6.

[0050] The pair of wires 14 are flexible in a direction intersecting the longitudinal direction of the wires 14 and are arranged along one main surface 11c of the elongated section 11, as shown in Figure 2(a). As shown in Figure 1 and other figures, each of the pair of wires 14 is provided to connect the removal head 13 and the handle 122.

[0051] The pair of wires 14 are provided to change the state of the removal head 13 between a released state and a held state depending on whether the handle 122 is operated or not. That is, when the operator operates the handle 122 away from the long section 11, the pair of wires 14 are pulled from the tip 11b side to the base 11a side. As a result, the removal head 13 changes state from the released state to the held state. On the other hand, when the operator operates the handle 122 closer to the long section 11, the weight of the head component 130 causes the pair of wires 14 to return to the -X side so that the removal head 13 is in the state shown in Figure 5. As a result, the removal head 13 changes state from the held state to the released state.

[0052] As shown in Figure 5, one end of each of the pair of wires 14 is fixed to a head component (farthest head component) 130a located at the position furthest from the longest section 11.

[0053] As shown in Figures 1 and 2(a), the signal cable 24 is routed along the other main surface 11d of the elongated section 11 from the gripping section 12 to the removal head 13. Although not shown in detail, the signal cable 24 is connected to a motor 132d (see Figure 4) provided on each head component 130.

[0054] 2. Detailed structure of head component 130 As shown in Figure 4, each of the multiple head components 130 includes a connecting guide 131 and a head body 132 attached to the connecting guide 131. The connecting guide 131 is provided to connect adjacent head components 130 together. Specifically, the connecting guide 131 is integrally formed with one bottom wall portion 131a and two side wall portions (erect wall portions) 131b that rise from both ends of the bottom wall portion 131a in the Y direction toward the +Z side (the direction of curvature when the removal head 13 is in a holding state).

[0055] The bottom wall portion 131a is integrally formed with a main body portion 131f having a rectangular parallelepiped shape flattened in the Z direction, a shaft support portion 131h projecting from the main body portion 131f toward one side (-X side) in the connection direction between the head components 130, and a shaft support portion 131i projecting toward the other side (+X side) in the connection direction between the head components 130. Through holes 131j and 131k are provided in each of the shaft support portions 131h and 131i, penetrating in a direction (Y direction) that intersects both the curvature direction and the connection direction. Connecting pins 133 (see Figure 3) are inserted into the through holes 131j and 131k. By inserting the connecting pins 133 into the through holes 131j and 131k in this way, adjacent head components 130 are connected (pin-coupled).

[0056] As shown in Figures 4 and 6, the through holes 131j and 131k in the connecting guide 131 are located on the outer side of the curve when the removal head 13 is in a holding position (radially outward when the removal head 13 is in a curved position, as shown in Figure 6). As a result, as shown in Figure 6, the removal head 13 is configured to curve toward the opposite side of the portion (supported portion 131h, 131i) where the connecting pins 133 are inserted into the through holes 131j and 131k of each head component 130 and pivotally supported, when the pair of wires 14 are pulled toward the gripping portion 12 by the operator operating the handle 122.

[0057] The two side wall portions 131b face each other with a gap between them. Each of the two side wall portions 131b has an axial hole 131c and a through hole 131e. The axial hole 131c is provided so as to penetrate each side wall portion 131b in its thickness direction (the direction in which the side wall portions 131b face each other). The axial hole 131c is the hole to which the head body 132 is attached, and is formed in an elongated shape to prevent the relative rotation of the head body 132 with respect to the connecting guide 131.

[0058] The through-hole 131e is a hole that penetrates the side wall portion 131b in the width direction in the direction of connection (X direction) between the multiple head components 130. A wire 14 is inserted through the through-hole 131e (see Figure 5). As shown in Figure 3, the furthest head component 130a, which is the head component 130 furthest from the long portion 11 among the multiple head components 130, also has a through-hole 131e. However, for the furthest head component 130a, the wire 14 may be fixed to the side wall portion 131b, and the through-hole 131e is not necessarily required.

[0059] Each of the pair of wires 14 is inserted longitudinally through a through hole 131e provided in the head components 130 (intermediate head components) 130, excluding the furthest head component 130a, between the furthest head component 130a and the handle 122.

[0060] Each of the two side wall portions 131b has a beveled portion 131d on the upper part (+Z side portion) of the end face (side surface) 131g facing the connection direction (X direction) between the multiple head components 130. The beveled portions 131d are provided on both sides in the connection direction (X direction). Both beveled portions 131d have a shape in which the width of the side wall portion 131b gradually decreases as it moves away from the side of the bottom wall portion 131a (-Z side) to the opposite +Z side. That is, the beveled portion 131d is formed in a shape in which the +Z side of the end face 131g of the side wall portion 131b is cut off.

[0061] As shown in Figure 4, the inclined surfaces 131d provided on both sides of the side wall 131b in the connection direction are arranged such that the width of the side wall 131b in the connection direction (X direction) gradually decreases as it moves away from the pivot support portions 131h and 131i toward the +Z side.

[0062] As shown in section H of Figure 6, the inclined portion 131d is configured such that when the pair of wires 14 are pulled by the operator's operation of the handle 122 and the removal head 13 is held in place, the inclined portions 131d of adjacent head components 130 come into contact with each other.

[0063] In the scale removal unit 1 according to this embodiment, when drawing virtual lines L1 and L2 along the inclined surfaces 131d formed on both end faces 131g of the side wall portion 131b, the location Ax where each virtual line L1 and L2 is pivotally supported 130 The sloped section 131d is formed so as to pass through. However, the location Ax where the imaginary lines L1 and L2 are pivotally supported. 130 The inclined portion 131d may be formed in a shape that does not pass through the sloping portion.

[0064] As shown in Figure 5, in a natural state where the pair of wires 14 are not being pulled in the direction of arrow E (a state in which no tension is applied to the pair of wires 14), the removal head 13 is in a released state, rather than in a curved state (held state) as shown in Figure 6. As shown in Figures 7(a) and (b), in the released state, the removal head 13 can pass through the gap G between the pipes 501. Specifically, in the released state, the upper ends (+Z side ends) of the inclined surfaces 131d of the connecting guides 131 of adjacent head components 130 are separated by a gap G1. In this case, between adjacent head components 130, the portion of the end face 131g of the side wall 131b that is on the -Z side of the inclined surface 131d is also separated.

[0065] As shown in Figure 4, the head body 132 has a cylindrical portion 132a and two shaft portions 132b that protrude outward from the +Y and -Y (both sides in the direction of the cylindrical axis) end faces 132g of the cylindrical portion 132a. The cylindrical portion 132a contains a vibration generating component consisting of a motor 132d and an eccentric weight 132e built inside. Although only one head component 130 is shown in Figure 4, each of the nine head components 130 has a vibration generating component built inside. However, the vibration generating component only needs to be provided in at least one of the multiple head components 130.

[0066] The cylindrical portion 132a has a projection 132c formed to protrude radially outward from a part of its outer circumferential surface. The projection 132c of the head body 132 has a pointed tip. In this embodiment, the projection 132c has multiple (for example, three) tips. However, the number of tips of the projection 132c may be two or less, or four or more. Furthermore, fine, file-like projections 132c may be formed in a continuous manner.

[0067] As shown in section H of Figure 6, the projection 132c of the head body 132 is provided such that at least its tip protrudes radially inward from the upper end (the inner end of the arc) of the side wall portion 131b. As a result, when the removal head 13 is held in place, the tip of the projection 132c locally contacts the scale 502.

[0068] 3. Scale removal method using scale removal unit 1 A method for removing scale 502 using the scale removal unit 1 according to this embodiment will now be described. First, as shown by the arrow J1 in Figure 7(a), the removal head 13 and the long section 11 of the scale removal unit 1 are inserted towards the deep section 500b by passing through the gap G between the pipes 501. In this case, the handle 122 is not operated by the operator, and the removal head 13 is in a state where it extends in a straight line (released state). By keeping the removal head 13 in a straight line without bending it in this way, even when the gap G between the pipes 501 is about 10 mm or less, the removal head 13 is prevented from getting caught on the pipes 501 in the middle. Therefore, as shown in section J2 of Figure 7(b), the removal head 13 is advanced towards the deep section 500b while avoiding the pipes 501 in the middle.

[0069] Furthermore, in this embodiment, the elongated portion 11 is a plate material (a single plate material) that is flexible in the thickness direction, and is provided with a plate thickness of 1 mm or less, so the elongated portion 11 can also be advanced toward the deeper portion 500b so as to avoid the pipe 501 in the middle. Therefore, the removal head 13 and the elongated portion 11 are prevented from getting caught on the pipe 501 in the middle.

[0070] When the removal head 13 reaches the target pipe 501a located in the deep part 500b of the boiler 500, the operator operates the handle 122, which pulls the pair of wires 14 toward the base end 11a. As a result, the removal head 13 changes state from the released state shown in Figure 8(a) to the held state shown in Figure 8(b), and the tip of the projection 132c of the head component 130 comes into contact with the scale 502 attached to the outer surface 501b of the target pipe 501a, from the side downwards. Then, as shown in Figure 8(b), after the removal head 13 is in the held state, the operator operates the motor driver 21, which drives each motor 132d of the head component 130, causing the head body 132 to vibrate, and vibration is applied to the scale 502 from the tip of the projection 132c. Thus, scale removal is performed.

[0071] 4. Effects In the scale removal unit 1 according to this embodiment, the operator can change the state of the removal head 13 from the released state (the state shown in Figure 5) to the held state (the state shown in Figure 6) by operating the handle (operating part) 122. A pair of wires (connecting parts) 14 mechanically connect the removal head 13 and the handle 122. Therefore, the scale removal unit 1 can have a simpler configuration than a tool equipped with four motors 923, 926, 930, and 934 in the arm 919 for changing the state of the curved plate 902, as described in Patent Document 1.

[0072] Furthermore, in the scale removal unit 1, each of the multiple head components 130 is provided with a projection 132c extending radially inward in its curved position. By locally bringing the tip of the projection 132c into contact with the scale 502, it is possible to remove the scale 502 with high efficiency. Therefore, the scale removal unit 1 can efficiently remove the scale 502 even if the scale 502 adhering to the target pipe 501a is hard. In this embodiment, all of the multiple head components 130 are provided with projections 132c, but it is not necessary for all head components 130 to have projections 132c. It is sufficient for at least one head component 130 to have projections 132c.

[0073] Therefore, the scale removal unit 1 is a unit that can remove scale 502 adhering to the target pipe 501a while suppressing the increase in manufacturing cost and weight compared to the tool disclosed in Patent Document 1.

[0074] In the boiler 500, the gaps G between tubes 501 can be relatively wide or relatively narrow. To pass the removal head 13 through such a tube group and reach the target tube 501a, if the gaps G are relatively wide, it may be possible to insert the removal head 13 while it is in a held position. However, if the gaps G between tubes 501 are relatively narrow, as in the staggered arrangement of tubes shown in Figure 7, the removal head 13 cannot be inserted in the held position. By releasing the removal head 13, it may be possible to insert it smoothly without it getting caught on the intermediate tubes 501. Thus, with the scale removal unit 1, even when the gaps G between tubes 501 in the tube group are narrow, the removal head 13 can be smoothly inserted to the target tube 501a. Moreover, since the handle 122 and the removal head 13 are connected by a pair of wires 14, the pair of wires 14 can pass through together with the long section 11 even when the gaps G are narrow.

[0075] In the scale removal unit 1, the removal head 13 is composed of multiple head components 130 that are pivotally supported by each other. The multiple head components 130 are bent when a pair of wires 14 are pulled by operating the handle 122 until the separated portions (inclined portions 131d) of adjacent head components 130 come into contact. Therefore, in the scale removal unit 1, by making the radius of curvature of the bend when the inclined portions 131d of adjacent head components 130 come into contact smaller than the outer diameter of the target pipe 501a, it is possible to guide the removal head 13 along the scale 502 attached to the target pipe 501a. Thus, the scale removal unit 1 can efficiently remove the scale 502 with a simple configuration.

[0076] In the scale removal unit 1, each head component 130 is equipped with a connecting guide 131 having a beveled portion 131d on its side wall (wall portion) 131b, and the beveled portions 131d are formed such that when the removal head is in the holding state shown in Figure 6, the beveled portions 131d of adjacent head components 130 come into contact with each other. Therefore, in the scale removal unit 1, the curvature of the curvature of the removal head is defined by the inclination angle and size of the beveled portion 131d. In other words, in the scale removal unit 1, the curvature of the curvature of the removal head 13 can be defined by defining the inclination angle and size of the beveled portion 131d. Thus, in the scale removal unit 1 according to this embodiment, it is possible to bend the removal head 13 with a curvature corresponding to the outer diameter of the target pipe 501a.

[0077] In the scale removal unit 1, the furthest head component 130a has a fixing portion to which a pair of wires 14 are fixed, and the other head components 130, the intermediate head components 130, have through holes 131e through which the pair of wires 14 are inserted. Therefore, when the pair of wires 14 are pulled by the operator's operation of the handle 122, adjacent head components 130 rotate with the outer side of the curved surface, which is pivotally supported, until the inner sides of the curves come into contact with adjacent inclined surfaces 131d. In this way, the scale removal unit 1 can change the state of the removal head 13 from a released state to a held state with a simple configuration that does not include a motor as described in Patent Document 1. Therefore, the scale removal unit 1 can efficiently remove the scale 502 attached to the target pipe 501a by guiding the removal head 13 along the scale 502 while suppressing increases in manufacturing cost and weight compared to the tool disclosed in Patent Document 1.

[0078] In the scale removal unit 1, the vibration source (motor 132d, eccentric weight 132e) includes vibration generating components provided on each head component 130, so that the size of each vibration generating component can be reduced while ensuring the total vibration intensity against the scale 502. In other words, if a vibration source is provided on one of the multiple head components 130 and the vibrations generated by that source are transmitted to the other head components 130, it is necessary to provide a large vibration source capable of generating vibrations of high intensity. In contrast, in the scale removal unit 1, by distributing the vibration generating components on each of the multiple head components 130, it is possible to keep the size of each individual component small.

[0079] In the scale removal unit 1, the elongated section 11 is made of a single plate material that is flexible in the thickness direction. Therefore, as the removal head 13 is inserted into the deep section 500b where the target pipe 501a is located, the elongated section 11 can use its flexibility to avoid the pipe 501 in the middle. For this reason, in the scale removal unit 1, even when inserting the removal head 13 into a group of pipes arranged in a grid pattern, as well as a group of pipes arranged in a staggered pattern, the elongated section 11 can use its flexibility to prevent it from getting caught on the pipe 501 in the middle.

[0080] As described above, the scale removal unit 1 according to this embodiment can remove scale 502 adhering to the outer surface 501b of the target pipe 501a while suppressing increases in manufacturing costs and weight.

[0081] [Second Embodiment] The scale removal unit 1 according to the second embodiment will be described with reference to Figures 9 and 10.

[0082] As shown in Figure 9, the scale removal unit 1 according to this embodiment is composed of multiple strips (plate materials) 111, each having a long section 11 connecting the gripping section 12 and the removal head 13, arranged in series and connected to one another. This is the difference from the first embodiment described above.

[0083] As shown in section K of Figure 9, each of the multiple strip plates 111 constituting the elongated section 11 has two through holes 111c that pass through the end faces 111a and 111b facing adjacent strip plates 111. A wire 14 is inserted through the through holes 111c of each strip plate 111 in a movable manner.

[0084] Each strip plate 111 is made of a metal plate or a hard resin plate. In this embodiment, as an example, it is made of a metal plate (for example, a plate made of a metal material such as a steel plate, or a plate made of a non-ferrous metal material such as a titanium alloy).

[0085] As shown in Figure 10(a), when the operator is not pulling the handle 122, no stress (contact stress) acts between the end faces 111a and 111b of adjacent strip plates 111. In this state, adjacent strip plates 111 are connected by a pair of flexible wires 14, and the elongated section 11 becomes flexible at least in the thickness direction of the strip plates 111 (flexible state). Note that although Figure 10(a) shows a gap between adjacent strip plates 111, there is not necessarily a gap between the strip plates 111. In other words, the flexible state indicates that flexibility in the thickness direction of the elongated section 11 is ensured.

[0086] On the other hand, as shown in Figure 10(b), when the operator pulls the handle 122, the pair of wires 14 are pulled toward the gripping portion 12 (the side of the base end 11a), causing the end faces 111a and 111b of adjacent strip plates 111 to come into contact with each other, and stress (contact stress) acts between them. In this state, the orientation of the multiple strip plates 111 constituting the elongated portion 11 is constrained (constrained state). That is, as shown in Figure 7(b), when the operator pulls the handle 122 while the elongated portion 11 has moved past the pipe 501 in the middle, the orientation of the elongated portion 11 is constrained at that point.

[0087] In this embodiment, multiple strip plates 111 are connected by a pair of wires 14, but it is also possible to connect them with a flexible member other than the pair of wires 14 (a linear or membrane-like elongated member). In this case, by connecting one end of the connecting member that connects the strip plates 111 to the handle 122, the operator can change both the state of the removal head 13 and the state of the elongated portion 11 with a single operation of pulling the handle 122.

[0088] In the scale removal unit 1 according to this embodiment, the configuration of the elongated portion 11 differs from that of the first embodiment, but the other configurations are the same. Therefore, the scale removal unit 1 according to this embodiment can also achieve the same effects as the first embodiment.

[0089] Furthermore, in the scale removal unit 1 according to this embodiment, multiple strip plates 111 are connected by a pair of wires 14. Therefore, compared to the case where the strip plates 111 are connected to each other by a flexible member other than the pair of wires 14, the number of parts constituting the scale removal unit 1 can be reduced, which is effective in suppressing increases in manufacturing costs and weight.

[0090] [Differentiation] In the first embodiment described above, the elongated portion 11 is flexible in the thickness direction, and in the second embodiment described above, the elongated portion 11 is flexible when in a flexible state. However, in the present invention, the elongated portion 11 does not necessarily have to be flexible. For example, the elongated portion 11 may be made of a rod or cylindrical material with an outer diameter smaller than the gap G between the pipes 501, or the elongated portion 11 may be made of a plate material that is thinner than the gap G and does not have flexibility.

[0091] Furthermore, while the first embodiment described above employs a configuration in which the elongated portion 11 is made of a single metal plate, the present invention also allows for the use of an elongated portion 11 made of a material other than metal. For example, the elongated portion 11 can be made of a strip-shaped fibrous material such as aramid fiber.

[0092] Furthermore, in the first and second embodiments described above, the handle 122 of the gripping portion 12 and the removal head 13 are connected by a pair of wires 14, but the present invention is not limited thereto. For example, the handle 122 and the removal head 13 may be connected by a single linear member (such as a wire or rope), or by three or more linear members. It is also possible to use a membrane-like member or a strip-like member as the connecting portion that connects the handle 122 and the removal head 13.

[0093] Furthermore, while the first and second embodiments described above employ a removal head 13 in which multiple head components 130 are connected by connecting pins 133, the present invention is not limited thereto. For example, a removal head 13 composed of a single member can also be employed. For instance, a removal head 13 made of a single member can be formed using an elastic material, and the state of the removal head 13 can be changed between a held state and a released state by the operator operating a handle (operating part) 122. This allows the removal head 13 to be in the released state to bypass intermediate pipes 501 until the target pipe 501a is reached, and then the removal head 13 to be in the held state to remove the scale 502 after reaching the target pipe 501a.

[0094] Furthermore, in the first and second embodiments described above, the other ends of the pair of wires 14 are connected to a handle 122, and the operator can pull the pair of wires 14 by operating the handle 122. However, the present invention is not limited to this. The connecting part of the wires 14 etc. only needs to be formed so that the other end extends to the gripping part, and the operator may directly pull the other end of the connecting part. In this case, the other end of the connecting part becomes the operating part.

[0095] Furthermore, in the first and second embodiments described above, the removal head 13 was configured to have a vibration source (motor 132d, eccentric weight 132e), but in the present invention, it is not necessarily required to provide a vibration source in the removal head 13. For example, after the removal head 13 reaches the target pipe 501a, the worker may move the scale removal unit 1 up, down, left, and right to remove the scale 502 by rubbing the tip of the projection 132c against the scale 502. [Explanation of Symbols]

[0096] 1 Scale removal unit 11 Long section 12 Grip part 13 Removal head 14 Wire (connecting part) 111 Strip board (wooden board) 122 Handle (operating part) 130 Head Components 130a Farthest Head Component 131 Linking Guide 131b Side wall (wall) 131d Slope 131h,131i Axial branch 132 Head Body 132c Protrusion 500 boilers 501 tube 501a Target pipe 502 scale

Claims

1. A scale removal unit for removing scale attached to a target pipe among the pipes that constitute a group of pipes in which many pipes are arranged with gaps between them, An elongated portion having a thickness that allows it to pass through the gap, A removal head is attached to the tip of the long section and is provided on a part of its outer surface, and has a pointed projection at its tip, An operating unit for an operator to operate the removal head, located outside the aforementioned pipe group, A linear or membrane-like elongated member that extends along the elongated portion and is flexible is formed, and a connecting portion that mechanically connects the removal head and the operating portion, Equipped with, The removal head is When the connecting portion is pulled along the elongated portion toward the base end opposite to the tip portion by the operator's operation of the control unit, the holding state is such that the tip of the projection contacts at least a portion of the scale adhering to the outer surface of the target pipe, If the operator does not operate the control unit, the release state is such that the gap can be passed through, It is configured to be variable between, Scale removal unit.

2. The removal head has a plurality of head components connected in series, each being pivotally supported by the other at the radially outer portion of the curved position. At least some of the head components among the plurality of head components are configured such that, when in the released state, the portions of adjacent head components other than the pivotally supported portion are separated, and as the state changes from the released state to the held state, the separated portions between adjacent head components bend until they come into contact with each other. A scale removal unit according to claim 1.

3. Each of the plurality of head components is provided with a connecting guide having a pivoted support portion that is pivotally supported for connecting with an adjacent head component, and a wall portion having a predetermined height in a direction perpendicular to the direction of connection with the adjacent head component. On the side surfaces of the wall portion in the connection direction, sloping portions are formed such that the width of the wall portion in the connection direction gradually decreases as it moves away from the pivot support portion in the direction perpendicular to the connection direction. The aforementioned inclined portion is configured to contact the inclined portion of the adjacent head component when in the holding state. The scale removal unit according to claim 2.

4. Of the plurality of head components, the furthest head component, which is the head component furthest from the elongated portion in the connecting direction, has a fixing portion to which the connecting portion is fixed. Of the plurality of head components, the intermediate head component, excluding the furthest head component, has a through hole through which the connecting portion is movably inserted in the portion that is radially inward of the curved position. The scale removal unit according to claim 2.

5. The removal head has a plurality of head components connected in series, each being pivotally supported by the other at the radially outer portion of the curved position. The projection is provided on at least one of the plurality of head components, projecting radially inward in the curved position. A scale removal unit according to claim 1.

6. The removal head has a vibration source capable of applying vibration to the projection. A scale removal unit according to claim 1.

7. The aforementioned elongated section is made of a single sheet of material that is flexible in the thickness direction. A scale removal unit according to any one of claims 1 to 6.

8. The aforementioned elongated section is composed of multiple plate materials arranged in series along the longitudinal direction of the elongated section and connected to one another. A scale removal unit according to any one of claims 1 to 6.

9. Each of the aforementioned plate materials has a through hole that allows the connecting portion to be inserted in a movable manner. The aforementioned elongated portion is, When the connecting portion is pulled toward the base end by the operation of the operating unit by the operator, adjacent plates come into contact with each other, resulting in a restrained state in which their orientation is constrained. When the operator does not operate the control unit, the plate material is in a flexible state where its posture is not constrained because no contact stress acts between the adjacent plate materials, It is configured to be variable between, The scale removal unit according to claim 8.

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