JP4002686B2 - Method for removing tube from tube plate and apparatus for cutting welded portion of tube of coal dryer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for removing a tube whose end is welded inside a mounting hole through which a tube plate disposed oppositely passes, and a welding part cutting device for a tube of a coal dryer to which the method is applied.
[0002]
[Prior art]
For example, a tube of a coal dryer that performs a preparatory process for producing coke is corroded by gas generated from coal, and cannot be used if the tube wall has a hole. However, not all 300 tubes can be used at the same time, and it is not economically efficient to make the life of the machine when some of the tubes cannot be used. On the other hand, if drying is performed only with a tube that can be used, the amount of coal that can be dried at one time decreases, and thermal efficiency deteriorates.
Therefore, it is trying to extend the mechanical life by exchanging the tube which has been used due to corrosion.
As shown in FIG. 7 (A), the coal dryer 150 is attached to a rotating shaft 154 having a diameter of about 1 m that is held obliquely via bearings 153 on both sides, and is a cylinder that rotates integrally with the rotating shaft 154. The drum 151 is an example of the form. A large number of tubes 152 are attached in the axial direction inside the drum 151. The coal dryer 150 is a very large machine. The drum 151 has a diameter of about 16 m and an axial length of about 9 m, and the replacement tube 152 has a diameter of about 0.3 m and a length of 8.5 m. It is about 840 kg / book.
[0003]
The end portion of the tube 152 is attached to the fixed tube plates 155 and 156 on both the upper and lower sides (left and right sides in the figure). As shown in FIG. 7B, for example, the lower side portion 157 of the tube 152 is expanded in diameter and closely fixed to the wall surface of the mounting hole 158 of the fixed tube plate 156 to increase strength and improve thermal efficiency. ing. The entire circumference of the lower end 159 is arc welded to further increase the strength.
When the coal is dried, the pulverized coal is put from the fixed tube plate 155 on the upper side of the drum 151 held obliquely, and is passed through the tube to dry the coal. During operation, heated steam is allowed to flow into the drum 151 for drying. The heated steam passes through the outside of the tube 152, heats the tube 152, the fixed tube plates 155 and 156, and the peripheral wall portion of the drum 151, and transfers the heat to the coal in the tube 152, thereby evaporating moisture inside the coal. The coal was drying. At this time, the drum 151 rotates at a constant speed around the rotation shaft 154. By this operation, the moisture content of coal can be reduced to a predetermined level, and coal that becomes a high-quality coke raw material can be obtained.
[0004]
However, the inner wall of the tube 152 is gradually corroded by the gas generated from the inside of the coal together with the water evaporated when the coal is dried. For this reason, the tube 152 with a hole needs to be replaced, and the following procedure has been considered for replacement.
(1) An operator enters from a manhole 161 provided at a key point on the peripheral wall of the drum 151.
(2) Gas cutting of the tube 152 is performed through a gap of about 300 mm.
(3) The cut tube 152 is carried out of the manhole 161.
(4) Remove the weld at the end by gouging. Or grind with a grinder and take out the fragments of the tube.
(5) Insert a new tube with the help of the worker from the inside.
As described above, it has been considered that the tube of the coal dryer can be exchanged with the assistance from the inside of the dryer.
[0005]
[Problems to be solved by the invention]
However, the conventional method for replacing a coal dryer tube has the following problems.
(1) The gap between the tubes 152 when working in the drum 151 is only about 300 mm, and a working posture with a margin cannot be taken.
(2) The drum 151 is filled with gas fume and coal fine powder in the tube 152, and dust is scattered even after forced ventilation. If you do not change work in a short time, you will not have physical strength.
(3) There is a high risk of a fall accident of the cut tube residue in the upper and lower lapping work in a dark work environment.
(4) In addition, if the scattered coal powder ignites, it will cause a catastrophe.
(5) There is a high possibility that the cut tube residue cannot be sufficiently recovered, and when it is left in the drum 151, the performance of the coal dryer 150 is reduced.
As described above, it is very dangerous if a person enters the inside of a coal dryer to perform work, and if it is to be performed forcibly, it is a very time-consuming work.
The present invention has been made in view of such circumstances, and a method for removing a tube from a tube plate that can be operated safely and efficiently using an apparatus for performing the operation from the outside of the drum and the method are applied. It aims at providing the welding part cutting device of the tube of a coal dryer.
[0006]
[Means for Solving the Problems]
The method for removing a tube from a tube plate according to claim 1, wherein both ends of the tube are partially inserted into a mounting hole through which a fixed tube plate arranged opposite to each other, and the ends are welded on the inside. A tube having a circular cross-section formed is removed from the fixed tube plate arranged opposite to the tube, and one end of the fixed tube plate is sequentially or both at the same time through the fixed tube plate to the end of the tube in the radial direction. A step of attaching centering means having a diameter-enlarging claw projecting uniformly to the center, and inserting the tip of a rotating shaft, which is arranged in parallel to the tube and attached to the tube, into the centering means. The end of the tube connected to the one or both of the fixed tube plates and the end of the tube connected to the welded portion is finally fixed with the tube facing the other. Range that does not come off the tube sheet A step of removing, a step of removing the centering means from the tube, and a removable annular latching portion that latches on the opposite annular stepped portions cut by the blade on both sides of the tube, A step of attaching a tube removing jig provided with a plurality of jacks that abut one of the fixed tube plates from the outside and separate the tube from the opposed fixed tube plate; and the opposed fixed tube plate Gradually pulling out the tube separated from the opposite fixed tube plate.
[0007]
The method for removing a tube from the tube plate according to claim 2 is the method for removing a tube from the tube plate according to claim 1, wherein the tube removing jig is an outer tube to which the annular latching portion is attached. And a sliding member that slides along the outer tube with its axis aligned, and is longer than the distance between the fixed tube plates facing each other.
The method for removing the tube from the tube plate according to claim 3 is the method for removing the tube from the tube plate according to claim 1 or 2, wherein the centering means has an enlarged diameter portion on the back side, Is a cylindrical body having a bearing portion for supporting the rotating shaft, and the cylindrical body is fitted on the inner side, is disposed on the near side opposite to the enlarged diameter part, and is annularly enlarged together with the opposed enlarged diameter part. A fastening ring that forms a groove, a fastening nut that is screwed into a male screw portion on the front side of the cylindrical body and presses the fastening ring, and a support member having a base end fixed to the fastening ring. A guide member which is arranged further on the front side of the fastening nut and aligns the shaft center of the centering means with the shaft core of the tube, and is fitted into the annular enlarged V-shaped groove, and moves to the back side of the fastening ring. The plurality of diameter-enlarging claws that slide and move in the radial direction.
The method for removing a tube from the tube plate according to claim 4 is the method for removing a tube from the tube plate according to any one of claims 1 to 3, wherein the opposed fixed tube plate is rotationally driven in the center. It is an end plate which opposes the coal dryer which is equipped with the main axis | shaft which is made and puts the coal thrown into a coke oven into the said tube, and dries.
[0008]
6. The apparatus for cutting a welded portion of a tube of a coal dryer according to claim 5, wherein the fixed tube plate is provided opposite to both sides of the cylindrical body, and the fixed tube is located inside the cylindrical body, and both sides of the fixed tube face each other. A welding section cutting device for a coal dryer tube having a plurality of tubes fixedly welded to a plate, wherein the tip portion is supported by centering means provided in the tube, and a cutter is provided in the middle. A rotating shaft, a motor that rotationally drives the rotating shaft, and the motor and the rotating shaft are mounted, in the y direction parallel to the axis of the tube, and in the x and z directions orthogonal to the axis of the tube A movable three-dimensional table; and a fixing means for attaching the three-dimensional table to a main shaft provided on an axis of the fixed tube plate.
The welding unit cutting device for a tube of a coal dryer according to claim 6, wherein the fixing unit is attached to a bottom frame of the three-dimensional table in the welding unit cutting device for a tube of a coal dryer according to claim 5, A front leg and a rear leg that are paired in the front and rear directions that are in contact with the upper four positions of the main shaft, a chain that connects the paired front leg and the rear leg, respectively, and a chain tension means that is attached to one of the fixing means Have.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention.
As shown in FIGS. 1A, 1B, 2, and 4, a tube whose end is welded to a tube sheet to which the method for removing the tube from the tube plate according to an embodiment of the present invention is applied. The removing device 10 includes centering means 11a, a welding portion cutting device 47, and a tube removing jig 81. The centering means 11 a is attached to the inside of the tube 20, and the bearing portion 12 of the centering means 11 a is fitted with the rotating shaft 74 of the welded portion cutting device 47. Further, the tube removing jig 81 can sandwich and fix the tube 20 after removing the centering means 11a and the welding portion cutting device 47. This will be described in detail below.
As shown in FIGS. 1A and 1B, the centering means 11a includes a fixing member 11 that is fixedly disposed in the tube 120 and has a bearing portion 12 that fits with the rotating shaft 74 of the welding portion cutting device 47. Have. The fixed member 11 has a bearing 12 that supports the rotating shaft 74 of the welded portion cutting device 47 shown in FIG. 2 fixed on the inner side, a male screw portion 13 formed on the front side (left side in FIG. 1), and a rear side ( The right side in FIG. 1 has a cylindrical body 15 which is an expanded diameter portion 14 having an enlarged diameter. The cylindrical body 15 is fitted inside, and is disposed on the front side so as to face the enlarged diameter portion 14. The annular enlarged V-shaped groove 18 is formed together with the opposed enlarged diameter portion 14, and the outer diameter is the expansion of the cylindrical body 15. The fastening ring 16 that is substantially the same as the diameter portion 14 is disposed between the fastening body 17 and the tubular body 15 having a female threaded portion that is screwed with the male threaded portion 13 of the tubular body 15, and is pressed by the fastening nut 17. A hole 23 having a diameter larger than the inner diameter of the bearing portion 12 is formed in the bag portion of the fastening nut 17.
[0010]
In the cylindrical body 15, the fastening ring 16, and the fastening nut 17 in the screwed state, the annular enlarged V-shaped groove 18 between the side portions facing each other of the tubular body 15 and the fastening ring 16 has a substantially V-shaped cross section in the axial direction. Yes. A plurality of (four in this embodiment) diameter-enlarging claws 19 having a V-shaped cross-section aligned with the annular enlarged V-shaped groove 18 have a latching portion 19a on the side surface, and the annular enlarged V-shaped groove 18 The cylinder 15 or the fastening ring 16 is hooked on a groove 16a provided on one side or both sides. This prevents the diameter-enlarging claw 19 from falling off in the radial direction. When the fastening nut 17 is fastened, the fastening ring 16 moves to the back side, and the width of the annular enlarged V-shaped groove 18 becomes narrow. The plurality of diameter-enlarged claws 19 are pressed against the side surface from both sides and protrude evenly outward in the radial direction of the bearing portion 12. Conversely, when the fastening nut 17 is loosened, the groove width of the annular enlarged V-shaped groove 18 is increased, and the diameter-enlarging claw 19 is moved inward in the radial direction of the bearing portion 12. Since the cross-sectional shape in the axial direction of the annular enlarged V-shaped groove 18 is substantially the same regardless of the position in the circumferential direction, the moving distance in the radial direction of the plurality of enlarged diameter claws 19 is also substantially the same. With this structure, the shaft core of the bearing portion 12 can be aligned with the shaft core of the tube 20 having a circular cross section.
[0011]
The number of the diameter expanding claws 19 is arbitrary as long as it is a plurality of 2 or more, but 3 or more is desirable. Further, it may be determined in consideration of the weight of the fixing member 11 and the weight. In this embodiment, it is provided at four positions every 90 degrees. The fixing member 11 has a weight of about 19 kg and can be transported and operated by human power. Therefore, the work can be performed easily and quickly.
[0012]
Inside a drum which is an example of a cylindrical body, both end portions 32 are partially inserted into mounting holes 31 and 97 that pass through fixed tube plates 30 and 96 (see FIG. 5) opposed to each other, respectively, When the fixing member 11 is attached to the tube 20 whose end portion 32 is fixed by welding, as shown in FIG. 1, the male screw portions 24 and 25 are formed on both sides so that the guide member 21 and the fixing member 11 are parallel to each other. The member 22 is used and temporarily fixed.
On the front side of the fastening ring 16, female thread portions 26 are formed, for example, every 120 degrees, and the male thread portion 24 on one side of the support member 22 is screwed thereto. The guide member 21 is provided with an insertion hole 27 through which the male screw portion 25 on the other side of the support member 22 is inserted. Since the insertion hole 27 is larger than the diameter of the male screw portion 25 and smaller than the diameter of the support member main body 28 (portion other than the screw portion), when the male screw portion 25 is fastened with the nut 29 via the guide member 21, the guide member 21 is fastened. The distance from the side of the ring 16 can be kept constant and fixed. As a result, the axis of the centering means 11 a and the axis of the bearing portion 12 can be matched with the axis of the tube 20.
[0013]
The shape of the guide member 21 is arbitrary, but as shown in FIG. 1 (B), it can be fitted into the mounting hole 31 of the tube 20 opened in the fixed tube plate 30, and at least a part of the outer peripheral portion is the end of the tube 20. It is necessary to hang on the part 32. In the present embodiment, each apex portion is hooked to the end portion 32 of the tube 20 as a substantially triangular shape, but the entire circumferential portion may be hooked in a circular shape.
Although three support members 22 are used in the present embodiment, it is desirable to use three or more support members 22 in order to prevent the fixing member 11 from being twisted.
[0014]
At the time of attachment, the fixing member 11 and the guide member 21 are inserted into the tube 20 from the fixing member 11 side in a state of being temporarily fixed by the support member 22 and the nut 29. At this time, since the fastening nut 17 is in a loosened state, the diameter-enlarging claw 19 does not hit the inside of the tube 20.
After the guide member 21 is inserted until it is hooked on the end portion 32 of the tube 20, as shown in FIGS. 1A and 1B, the fastener 34 is placed in the center of the guide member 21 with the fastening nut 17. The hole 23 and the shaft core are made the same, and the hole 23 is inserted into the hole 35 of the guide member 21 having a diameter larger than that of the fastener 34 and is brought into contact with the rear portion 36 of the fastening nut 17. The cylindrical fastener 34 is provided with, for example, four protrusions 37 in the axial direction at one end thereof. The rear portion 36 of the fastening nut 17 is formed with four groove portions 38 aligned with the protrusions 37 in the radial direction. The groove portion 38 can be substituted by hole processing with which the protruding portion 37 can be engaged. The handle 39 is inserted into a through hole 40 formed on the other side of the fastener 34, and the projection 37 of the fastener 34 that is in contact with the rear portion 36 of the fastening nut 17 is engaged with the groove 38 to fasten the fastening nut 17. To do. Then, the fastening ring 16 moves to the back side, and the plurality of diameter expanding claws 19 move radially outward to press the inside of the tube 20, whereby the fixing member 11 is fixed to the tube 20 with the same axis. The At this time, when the fastener 34 is fastened while pressing the rear portion 36 of the fastening nut 17, the guide member 21 comes into close contact with the end portion 32 of the tube 20, and the fixing member 11 becomes parallel to the guide member 21. Can be installed at a more accurate position.
[0015]
The mounting position of the bearing portion 12 (distance from the end portion 32 of the tube 20) can be determined by the length of the support member main body 28, and the position of the rotary shaft 74 and the blade 75 of the welded portion cutting device 47 to be fitted to It is good to decide in consideration of the length to cut.
After the fixing member 11 is fixed to the tube 20 by the diameter-enlarging claw 19, the nut 29, the guide member 21, and the support member 22 are removed, and the process of attaching the centering means is completed.
[0016]
As shown in FIG. 2, the weld cutting device 47 includes a coal dryer 41 that puts coal to be fed into a coke oven into a plurality of tubes 20 and dries it (the fixed tube plates 30 and 96 are opposed to the coal dryer 41). A bottom frame 43 that is fixed on a main shaft 42 that is rotationally driven at the center of the center plate, and a three-dimensional table 43a that is attached to the bottom frame 43 and that can be moved and fixed independently in the x, y, and z directions. The three-dimensional table 43 a includes an X table 44, a Y table 45, a Z table 46, and an intermediate cutting device 47 a fixed to the Z table 46. This will be described in detail below. The direction parallel to the axis of the tube 20 is defined as the y direction, the horizontal direction orthogonal to the axis of the tube 20 is defined as the x direction, and the vertical direction is defined as the z direction.
The front leg 48 and the rear leg 49 which are provided at the bottom of the bottom frame 43 and come into contact with the upper four positions of the main shaft 42 have the same distance between the paired front leg 48 and rear leg 49. Since the back surfaces of the front legs 48 and the rear legs 49 are brought into contact with (or in combination with) the circumferential surface of the main shaft 42, the weights to be placed can be received by the surfaces. In the present embodiment, the back surfaces of the front leg 48 and the rear leg 49 are provided so as to be inclined 45 degrees to the left and right from the vertical direction when viewed in the y direction. The front leg 48 and the rear leg 49 function in the same manner as the V block, and the orientation of the axis of the main shaft 42 and the axis of the rotary shaft 74 of the weld cutting device 47 can be achieved by simply placing the bottom frame 43 horizontally on the main shaft 42. Are parallel.
[0017]
The front leg 48 and the rear leg 49 facing each other have a latch part for latching the chain 50, and the front leg 48 or the rear leg 49 is latched to the rear leg 49 or the front leg 48. The chain tension means for connecting the chain 50 is provided. In the present embodiment, a bolt member 51 is attached to the rear leg 49 side of the chain 50, and the fastening portion of the rear leg 49 is fastened using a fastening nut 52. As a result, the bottom frame 43 can be firmly fixed on the main shaft 42. The front leg 48, the rear leg 49, the chain 50, and the chain tension means constitute a fixing means.
Two rails 53 are fixedly arranged in the x direction on the bottom frame 43, and screws 54 are fixed to both sides via bearings 55 at the center. A handle 56 that can rotate the screw 54 is attached to one end of the screw 54. The X table 44 is attached to the screw 54 via a female screw member (not shown), and can move in the x direction along the rail 53 by rotating the handle 56.
[0018]
Two rails 57 are fixedly arranged on the X table 44 in the y direction, and a screw 58 is fixed to the center thereof via bearings 59 on both sides. The end of the screw 58 opposite to the fixed tube plate 30 on the X table 44 is connected to the feed motor 63 via gears 60 and 61 and a toothed belt 62. The Y table 45 is attached to the screw 58 via a female screw member (not shown), and by driving the feed motor 63, the Y table 45 can be moved in the y direction along the rail 57 at a constant speed. Thereby, an accurate feed amount at the time of cutting can be adjusted.
Horizontal plates 64 and 65 are provided in the vertical direction at both ends of the Y table 45 in the x direction. Two rails 66 are fixedly arranged in the z direction on one side horizontal plate 64 or 65, and a screw 67 is fixed to both sides via bearings 68 at the center. A handle 69 capable of rotating the screw 67 is attached to an upper end portion of the screw 67. The other lateral plate 65 or 64 is provided with two vertical grooves 70 in the z direction. The Z table 46 is attached to a screw 67 via a female screw member (not shown) at one end portion, and a guide portion 71 that is inserted into the longitudinal groove hole 70 is provided at the other end portion. By rotating the handle 69, the Z table 46 can move in the z direction along the rail 66.
[0019]
On the Z table 46, an intermediate cutting device 47a is fixedly arranged. The intermediate feed cutting device 47a has a motor 72 and a speed reducer 73, and a rotating shaft 74 provided in the speed reducer 73 is disposed with the main shaft 42 and the shaft core in parallel. A blade 75 is attached to the rotary shaft 74 via a fixture 76 that attaches the blade 75 in the radial direction of the rotary shaft 74. In the present embodiment, the distance from the center of the rotating shaft 74 to the tip of the blade 75 is about 1 mm smaller than the radius of the mounting hole 31 as shown in FIG. If this distance becomes larger than the radius of the mounting hole 31, the tube 20 is cut and dropped, and if it is made smaller, the load when it breaks with the hydraulic jack 89 (see FIG. 5) becomes too large. It is good to decide in consideration of the deformation state.
The diameter of the main shaft 42 of the coal dryer 41 is about 1 m, is provided on the shaft core of the fixed tube plates 30 and 96, and the height from the ground to the bottom frame 43 when the weld cutting device 47 is installed. Is about 7 m when high and about 5 m when low. For this reason, the welding part cutting device 47 is carried on the main shaft 42 using a crane or the like. The bottom frame 43 is fastened to the main shaft 42 by a bolt member 51 and a fastening nut 52 mounted on the chain 50 in a state where the welding part cutting device 47 is suspended by a crane. In the present embodiment, two chains 50 are used, but one or three or more chains may be used. Further, if the shape of the bottom frame 43 is increased in the x direction, the workability is improved, but the stability is deteriorated. For this reason, stability can be improved by supporting the back side of the bottom frame 43 from the ground with a jack (not shown).
[0020]
After the bottom frame 43 is fastened and fixed, the X table 44 and the Z table 46 are moved by the handles 56 and 69, and the mounting hole in which the fixing member 11 is mounted among the plurality of mounting holes 31 formed in the fixed tube plate 30. Adjust the center position to 31. For the center position, for example, a semicircular bearing is set in the mounting hole 31 and matched with this, or a dial gauge or the like is fixed to the rotating shaft 74 and is adjusted while rotating the rotating shaft 74. To do. Then, the Y table 45 is moved toward the fixed tube plate 30 at a minute speed by the feed motor 63, and the rotary shaft 74 is fitted into the bearing portion 12 of the fixed member 11. Then, the knife 75 is rotated by moving the Y table 45 toward the fixed tube plate 30 at a constant speed by the feed motor 63 while rotating the motor 72, and the welded portion 77 and the inner end of the tube 20 shown in FIG. The tube 78 can be cut within a range in which the tube 20 is not detached from the fixed tube plate 30 while leaving a minute thickness in the portion 78. In the present embodiment, since the distance from the center of the rotating shaft 74 to the tip of the blade 75 is about 1 mm smaller than the radius of the mounting hole 31, cutting can be performed without damaging the inside of the mounting hole 31. It is desirable that the cutting process is performed up to the inner end 79 of the mounting hole 31 as indicated by the hatched portion in the figure. In this state, when the tube 20 is broken by applying a tensile force in the axial direction, the tube 20 is broken at the position of the inner end portion 79.
Only the welded portion 77 may be cut. In this case, if the tube 20 is broken by applying a tensile force in the axial direction, the tube 20 is broken at the position of the welded portion 77. At the time of subsequent drawing, a large tensile force is required, but the machining time is short because there are few cutting parts.
[0021]
After cutting the end portion 32 of the tube 20, the centering means 11a is removed as shown in FIG. The support member 22 is fastened to the fixing member 11, the guide member 21 is engaged, and the nut 29 is fastened. Then, the fastening nut 17 is loosened by the fastener 34 and the handle 39, the fixing by the diameter-enlarging claw 19 is released, and the fixing member 11 is removed together with the guide member 21. As a result, the fixing member 11 can be used again.
In addition, although the process so far can also be performed in order from one of the fixed tube plates 30 and 96 (refer FIG. 5) provided facing both sides of the drum which is not illustrated, both can also be performed simultaneously. The construction period can be shortened by carrying out simultaneously.
[0022]
As shown in FIG. 4, the tube removing jig 81 includes an outer tube 81a inserted into the tube 20 indicated by a two-dot chain line, and an annular hooking portion 83a that can be removed on one side of the outer tube 81a. The provided jack member 82, the removable annular hooking portion 83 provided on the other side and hooked to the annular stepped portion 93a (see FIG. 3) of the tube 20, and the outer tube via the annular hooking portion 83 It has the cap nut 84 fastened and fixed to 81a. This will be described in detail below.
[0023]
A jack member 82 is attached to one side of the outer tube 81a. The jack member 82 has a central portion 85 in a sleeve shape and is fixed to the outer tube 81a. On the peripheral wall of the central portion 85, pins 86 attached to two pin holes penetrating through the center are provided, and the wire rope 87 (see FIG. 5B) can be attached. Yes. A jack mounting member 88 protruding in the radial direction is provided at a position rotated 90 degrees in the circumferential direction on the opposite side from the pin 86. The jack mounting member 88 includes a hydraulic jack 89 that is an example of a jack and faces the fixed tube plate 30 side. The number of attached hydraulic jacks 89 is arbitrary as long as it is two or more. In the present embodiment, two 45t hydraulic jacks 89 are used.
The end 90 on the other side of the outer tube 81a is internally threaded so that it can be fixed after the tube 20 is hooked by an annular hook 83. Inside the outer tube 81 a, a sliding member 91 that is slidably moved with the axis aligned with the outer tube 81 a and longer than the distance between the fixed tube plates 30 and 96 is attached. On one side of the sliding member 91, a sliding portion 92 formed so as to be slidable in the axial direction is attached to the inner peripheral surface of the outer tube 81a, and a latching portion 99a is provided at the other end. Is provided.
[0024]
When attaching the tube removing jig 81 to the tube 20, first, the outer tube 81a integrated with the jack member 82 is inserted from one side of the tube 20 (the right side in FIG. 5), and the annular hooking portion 83a is inserted into the annular step. It hooks on the part 93a. Then, the sliding member 91 is fitted from the other side of the outer tube 81a (left side in FIG. 5) from the sliding portion 92 side. Then, the cap nut 84 to which the bush 93 is attached is fitted from the front portion of the sliding member 91 via the annular latching portion 83 and engaged with the outer tube 81a, and the male threaded portion of the end portion 90 is formed. Conclude. The assembled sliding member 91 is slidable only in the axial direction of the outer tube 81a.
When the hydraulic jack 89 is operated from the state before the tube 20 shown in FIG. 5A is broken, the tube 20 is broken (separated) at the inner end portions 79, 79a of the fixed tube plates 30, 96. The inner end 79 on the drawing side is drawn into the annular stepped portion 93 a of the tube 20, but the remaining thin-walled portion 94 remains in the mounting hole 31 of the fixed tube plate 30. Sliding scratches due to the generated return or the like are protected by the thin wall portion 94, and the wall surface of the mounting hole 31 of the fixed tube plate 30 is not damaged.
[0025]
As shown in FIGS. 5A and 5B, after the tube 20 is broken by the hydraulic jack 89, the tube 20 is gradually pulled out by a winch (not shown) through the wire rope 87. In order to pull out the wire rope 87 in the axial direction of the tube 20, a pulley 96 a is attached to a wall 95 a (or a column or the like) on an extension line in the axial direction, and the wire rope 87 may be attached to the winch through this. When the winch is pulled up, the rear end portion 95 of the cap nut 84 attached to the outer tube 81a passes through the inner end portion 79a of the fixed tube plate 96 on the lower side of the inclined tube 20 as shown in FIG. As shown, a semicircular bearing 98 is mounted in the mounting hole 97 of the fixed tube plate 96. As a result, it is possible to prevent the fixed tube plate 30 from being cantilevered at the time of pulling out, and to prevent deformation of the mounting hole 31 of the fixed tube plate 30 and to stabilize the operation.
[0026]
The protruding portion 99 of the sliding member 91 is provided with a latching portion 99a, and the wire rope 100 can be attached thereto. When pulling out, the wire rope 100 is attached to the latching portion 99a and fixed on the extension line in the axial direction of the tube 20.
A suspension member 101 is disposed on the upper portion of the tube 20 of the drawing-out side fixed tube plate 30 using a crane or the like. The suspension member 101 includes a fixed tube portion 102 whose outer diameter is substantially the same as the inner diameter of the tube 20, a fixed base portion 103 that is fixed to the fixed tube portion 102 and is hooked on the fixed tube plate 30, and a fixed base portion 103. In the axial direction of the tube 20, it has a beam member 104 provided so as to protrude outward (withdrawal side) from the fixed tube plate 30, and a tension member 105 that pulls and supports the tip of the beam member 104 and the fixing base 103. Yes. The beam member 104 is provided with a plurality of hoists 107 that are movable in the length direction and have a rope 106 that is an example of a hanging tool. The fixed tube portion 102 of the hanging member 101 can be freely inserted and removed, and can be moved depending on the position where the tube 20 is pulled out. The position of the suspension member 101 is arbitrary as long as it is the position of the attachment hole 31 on the upper side of the tube 20, and may be determined in consideration of the length of the rope 106. In addition, when pulling out the tube 20 on the outermost periphery of the fixed tube plate 30, in order to attach the suspension member 101, the position can be adjusted by rotating the drum.
[0027]
The hoist 107 is moved until the tube 20 is completely pulled out (the state shown in FIG. 5B), the tube 20 is fastened together with the tube removal jig 81 by the rope 106, and the hoist 107 is suspended. Keep it. The number of hoists 107 may be any number as long as it is two or more.
When the tube 20 is completely pulled out, the tube 20 and the tube removal jig 81 are suspended from the suspension member 101, so that the subsequent carrying work by a crane (not shown) can be performed quickly.
[0028]
After the tube 20 has been pulled out and transported by the crane, a new tube is attached. Before the attachment, it is necessary to remove the welded portion remaining in the attachment holes 31 and 97 of the fixed tube plates 30 and 96 and the broken pieces of the tube 20. In order to remove, it is removed by polishing with a hand grinder.
As shown in FIGS. 6A and 6B, a new tube 108 is inserted after the welded portion and broken pieces are removed. At this time, insertion is performed from the mounting hole 31 side of the upper fixed tube plate 30.
A wire rope 107 a is passed inside the sliding member 91. As the wire rope at this time, the wire rope 100 shown in FIG. 5B used at the time of drawing may be used. In order to use the wire rope 100, a portion of the wire rope 100 that is hooked on the hooking portion 99a of the sliding member 91 is pulled out to the outside of the fixed tube plate 30 and pulled by using a magnet or the like. It is fixed to the outer side of the fixed tube plates 30 and 96 by being hooked on the stop member. While the wire rope 100 on the fixed tube plate 30 side is hooked, the end of the wire rope 100 on the fixed tube plate 96 side is passed through the inside in the order of the sliding member 91 and the cap nut 84. The tip of the sliding member 91 is inserted in the order of the cap nut 84, the attachment hole 31 of the fixed tube plate 30, and the attachment hole 97 of the fixed tube plate 96, and placed on the semicircular bearing 98 attached to the attachment holes 31 and 97. Keep it. When the wire rope 100 is not used, the wire rope 107a may be inserted from the sliding portion 92 side of the sliding member 91 and hooked to the hooking portion 99a before the work is performed.
[0029]
The outer tube 81a integrated with the jack member 82 is inserted from one side of the new tube 108 and temporarily assembled. In addition, when attaching a new tube 108, neither of the annular hooks 83 and 83a is used. This is because the new tube 108 is longer by the length of the portion where the tube 20 is cut. Therefore, the new tube 108 is hooked at the ends of the jack member 82 and the cap nut 84. The wire rope 107 a taken out from one side of the sliding member 91 is passed through a new tube 108 temporarily assembled and attached to the pin 86.
One side of the wire rope 107 a inserted through the sliding member 91 is pulled on the other side of the sliding member 91 on the extension line of the axis of the sliding member 91 by a winch and a pulley (not shown). The wire rope 109 attached to the pin 86 and pulled in the direction opposite to the wire rope 107a pulls the extension of the shaft core of the sliding member 91 to one side of the sliding member 91 by a winch and a pulley (not shown). After the cap nut 84 is fastened in the state shown in FIG. 6B, the two winches are interlocked, and the new tube 108 and the tube mounting jig 110 are inserted in the order of the mounting holes 31 and 97 while applying the tensile force. . Since both ends of the new tube 108 are not expanded, they are not press-fitted into the mounting holes 31 and 97 during insertion. The bearings 98 provided at two places are removed at the timing.
[0030]
After the insertion to the predetermined position, the cap nut 84 is removed, and the tube mounting jig 110 is removed while maintaining the installation position of the new tube 108. Although the mounting direction is not horizontal, it does not slide down due to friction between the new tube 108 and the fixed tube plates 30 and 96.
Then, both end portions of the new tube 108 are subjected to diameter expansion processing and are brought into close contact with the circumferential surfaces of the mounting holes 31 and 97. Furthermore, the strength can be increased by performing arc welding all around the edge or partially.
As is clear from the above explanation, in the conventional method that relies on human power, it is possible to easily perform the replacement of the tube of the coal dryer, whose safety has been questioned, from the outside. In addition, the construction period can be shortened compared to human work. Moreover, this invention is not restricted to replacement | exchange of the tube of a coal dryer, It is applicable also to the removal method of the tube from a tube sheet.
[0031]
In addition, this invention is not limited to the said embodiment, For example, the fixing member 11 and the fastener 34 are attached to the rotating shaft 74 of the welding part cutting device 47, and each table 44 of the welding part cutting device 47 is provided. , 45, 46, the fixing member 11 is inserted from the mounting hole 31 and fastened to the tube 20, thereby positioning the rotating shaft 74, positioning the bearing portion 12, and centering the welded portion cutting device 47. You can also.
[0032]
【The invention's effect】
In the method for removing the tube from the tube sheet according to claims 1 to 4, since a step of attaching a centering means having a diameter-enlarging claw that projects evenly is provided, eccentricity during cutting is prevented, and the circumferential portion Can be prevented from being partially cut off, and tilting during pulling out can be prevented.
Furthermore, since it cuts from the outer side of a tube, it can work safely.
Moreover, since the centering means is removed from the tube, the centering means can be reused.
And since the tube removal jig | tool with which the several jack was provided is mounted | worn, separation and extraction of a tube can be performed continuously from the outer side of a tube, and construction can be performed safely and rapidly.
In particular, in the method for removing the tube from the tube plate according to claim 2, the tube removing jig is attached to the inside of the tube with the outer tube to which the annular latching portion is attached. Can work on.
Moreover, since it has a sliding member longer than the distance of the fixed tube plate which opposes, the inclination of the tube during extraction is prevented and it can work safely.
[0033]
In the method for detaching the tube from the tube plate according to claim 3, the centering means has a plurality of diameter-enlarged claws that slide and move in the radial direction by means of screws, so that it does not depend on deformation of the shape in the tube. , Accurate centering can be performed.
Further, since the guide member is provided, the centering means can be attached and detached easily and accurately.
In the method for removing the tube from the tube sheet according to claim 4, since the opposed fixed tube sheet is an opposed end plate of the coal dryer, the steps of attaching and removing the centering means and removing the welded portion are performed. It can be done from both sides of the tube sheet at the same time, and the construction period can be shortened.
In the welding part cutting apparatus of the coal dryer of Claim 5, 6, since the front-end | tip part of a rotating shaft is supported by the centering member provided in the tube, the blurring of the axis | shaft at the time of cutting is suppressed. Can do.
In particular, in the welding part cutting device for a tube of a coal dryer according to claim 6, the welding part cutting device has a front leg and a rear leg which are paired in front and back and abut on the upper four positions of the main shaft. The axial direction of the rotating shaft to which the cutter is attached can be provided in parallel with the main axis of the coal dryer simply by placing the blade.
[Brief description of the drawings]
FIGS. 1A and 1B are an exploded perspective view and a sectional view of a centering means of a tube detaching apparatus to which a method of detaching a tube from a tube plate according to an embodiment of the present invention is applied, respectively. is there.
FIG. 2 is a perspective view showing the welding part cutting apparatus.
FIG. 3 is a partial cross-sectional view of a fixed tube plate and a tube.
FIG. 4 is a perspective view of a tube removing jig of a tube removing device to which a tube removing method from a tube plate according to an embodiment of the present invention is applied.
FIGS. 5A and 5B are cross-sectional views showing a use state when the tube of the tube removal jig is removed, respectively.
FIGS. 6A and 6B are cross-sectional views showing a usage state when a tube of the tube attachment jig is attached, respectively.
7A and 7B are a front view of a coal dryer according to a conventional example, and a partial cross-sectional view of the fixed tube plate and tube, respectively.
[Explanation of symbols]
10 Tube removal device 11 Fixing member
11a Centering means 12 Bearing part
13 Male thread part 14 Enlarged diameter part
15 cylinder 16 fastening ring
16a Groove part 17 Fastening nut
18 Annular enlarged V-shaped groove 19 Expanded claw
19a Hook 20 tube
21 Guide member 22 Support member
23 Hole 24 Male thread
25 Male thread 26 Female thread
27 Insertion hole 28 Support member body
29 Nut 30 Fixed tube plate
31 Mounting hole 32 End
34 Fastener 35 Hole
36 Rear 37 Projection
38 Groove 39 Handle
40 through holes 41 Coal dryer
42 Spindle 43 Bottom frame
43a 3D table 44 X table
45 Y table 46 Z table
47 Welding section cutting device 47a Intermediate cutting device
48 Front legs 49 Rear legs
50 Chain 51 Bolt member
52 Fastening nut 53 Rail
54 Screw 55 Bearing
56 Handle 57 Rail
58 Screw 59 Bearing
60 gears 61 gears
62 Toothed belt 63 Feed motor
64 Horizontal plate 65 Horizontal plate
66 rail 67 screw
68 Bearing 69 Handle
70 Vertical groove 71 Guide part
72 Motor 73 Reducer
74 Rotating shaft 75 Blade
76 Fixing fixture 77 Welded part
78 Inner end 79 Inner end
79a Inner end 81 Tube removal jig
81a Outer tube 82 Jack member
83 Annular latching part 83a Annular latching part
84 Cap nut 85 Central part
86 pin 87 wire rope
88 Jack mounting member 89 Hydraulic jack (jack)
90 End 91 Sliding member
92 Sliding part 93 Bush
93a annular step portion 94 thin portion
95 Rear end 95a Wall
96 Fixed tube plate 96a Pulley
97 Mounting hole 98 Bearing
99 Projection 99a Hook
100 Wire rope 101 Hanging member
102 Fixed pipe section 103 Fixed base section
104 Beam member 105 Tensile member
106 Rope 107 Hoist
107a wire rope 108 new tube
109 Wire rope 110 Tube mounting jig

Claims (6)

A method of removing a circular tube having a circular cross-section in which both end portions are partially inserted into the mounting holes penetrating the opposed fixed tube plate and the end portions are welded on the inner side from the fixed tube plate arranged opposite to each other. There,
A step of attaching a centering means having an enlarged claw projecting uniformly in the radial direction to the end of the tube through the fixed tube plate sequentially or both simultaneously from any one of the fixed tube plates;
The centering means is placed in parallel with the tube, and the tip of a rotating shaft to which a cutter is attached is inserted, the welded portion is cut with the cutter, and finally one of the fixed tube plates Removing one or both of the welded portions and the end of the tube connected to the welded portion within a range in which the tube does not come off from the opposing fixed tube plate, leaving a minute thickness;
Removing the centering means from the tube;
The tube has a detachable annular latching portion that latches on opposite annular stepped portions cut by the blade on both sides, one of which is in contact with one of the fixed tube plates from the outside, and the tube Attaching a tube detaching jig provided with a plurality of jacks for separating the opposite fixed tube plate;
Gradually pulling out the tube separated from the opposed fixed tube plate from the opposed fixed tube plate;
A method for removing a tube from a tube sheet, comprising: The tube detaching jig includes an outer tube to which the annular latching portion is mounted, and a sliding member that slides and moves with the outer tube aligned with the axis, and is longer than the distance between the opposing fixed tube plates. A method for removing a tube from the tube sheet according to claim 1. The centering means has a bulging portion on the back side and a cylindrical body having a bearing portion that supports the rotating shaft on the inner side, and the cylindrical body is fitted on the inner side to face the bulging diameter portion. A fastening ring that is disposed on the near side and that forms an annular enlarged V-shaped groove together with the opposed expanded diameter portion; a fastening nut that is screwed into a male thread portion on the near side of the cylindrical body and presses the fastening ring; A guide member disposed on the further front side of the fastening nut via a support member whose base end is fixed to the fastening ring and aligning the axis of the centering means with the axis of the tube; The tube from the tube sheet according to claim 1 or 2, further comprising a plurality of said diameter-enlarged claws that are fitted into the enlarged V-shaped groove and slide in a radial direction by moving the fastening ring toward the back side. How to remove. The opposing fixed tube plate is an end plate that is opposed to a coal dryer that includes a main shaft that is rotationally driven in the center, and that puts coal to be fed into a coke oven into the tube for drying. 2. A method for removing a tube from the tube sheet according to item 1. A fixed tube plate provided opposite to both sides of the tubular body, and a tube of a coal dryer having a plurality of tubes inside the tubular body, both sides of which are welded and fixed to the opposed fixed tube plate A weld cutting device,
The tip portion is supported by centering means provided in the tube, and a rotary shaft provided with a cutter in the middle, a motor that rotationally drives the rotary shaft, the motor and the rotary shaft are mounted, A three-dimensional table that can be moved and adjusted in the y direction parallel to the axis of the tube and in the x and z directions perpendicular to the axis of the tube, and the three-dimensional table provided on the axis of the fixed tube plate A welding device cutting device for a tube of a coal dryer having a fixing means attached to a main shaft. The fixing means is attached to a bottom frame of the three-dimensional table, and a front leg and a rear leg that are paired with the front and rear pairs that are in contact with the upper four positions of the main shaft, and a chain that connects the paired front leg and the rear leg, respectively. 6. The apparatus for cutting a weld portion of a tube of a coal dryer according to claim 5, further comprising chain tension means attached to one of the respective chains.

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