JP2006038790A - Band-saw cutting device and cutting method for nuclear equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a band-saw cutting device and cutting method for nuclear equipment remotely performing replacement of a band saw. <P>SOLUTION: The band-saw cutting device 1 for nuclear equipment comprises: a turntable 3 for placing and rotating nuclear equipment 2 that is a member to be machined; a band saw unit 10 for cutting the nuclear equipment 2 placed on the turntable 3 by a band saw 11; a lifting truck 6 detachably mounting the band saw unit 10; and a vertical column 4 set near the nuclear equipment 2 with the lifting truck 6 being attached to be liftable. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

 The present invention relates to a band saw cutting apparatus for nuclear equipment and a cutting method thereof, and more particularly to a band saw cutting apparatus for nuclear equipment used for dismantling nuclear equipment and a cutting method thereof.

 In recent years, nuclear power plants have become more and more sophisticated, and constructions such as replacement, disposal, and decommissioning of a part of the facilities are being or are planned. In this process, the dismantling of the reactor internals is done by placing the material to be cut in a water-filled pool inside the reactor building from the viewpoint of reducing the radioactive exposure of employees due to radioactive materials. Cutting is performed by a cutting method or a high-pressure water cutting method.

  Conventionally, it is generally known that a band saw cutting device has been used for cutting a metal material such as a round bar, a steel pipe, and a die steel. In this band saw cutting device, a band saw arranged in a loop shape is driven by a motor or the like to cut a material to be cut. However, the conventional band saw cutting apparatus has a disadvantage that the apparatus is generally large, it is difficult to replace the band saw, and it takes a long cutting time. Such plasma cutting or high pressure water cutting with few disadvantages is used.

 However, in both the plasma cutting method and the high pressure water cutting method, the double structure portion having a gap inside the material to be cut cannot be cut integrally. Further, in the plasma cutting, cutting fumes and dross are generated, and it is difficult to recover such generated substances. In high-pressure water cutting, it has been found that the abrasive grains contained in the high-pressure water are scattered in a pool filled with water in the reactor building used in the cutting operation, and it is difficult to collect the abrasive grains. .

For this reason, it is possible to integrally cut a double structure portion having a gap inside the material to be cut, and the application of a band saw cutting device that can easily process chips generated in this cutting has been reviewed (for example, a patent) Reference 1).
Japanese Patent No. 2967800

 However, in the above-described conventional band saw cutting device, the material to be cut such as the reactor internal structure is activated, so from the viewpoint of reducing the radiation exposure of employees, a pool filled with water in the reactor building The material is cut by remote control. For this reason, even when the cutting edge of the band saw of the band saw cutting device is worn out and needs to be replaced, it is difficult to grasp the worn state of the cutting edge of the band saw.

 Further, in the band saw of the conventional band saw cutting apparatus, it is necessary to adjust the position of the guide reel of the band saw, relax the tension of the band saw, and exchange the looped band saw integrally. When this band saw replacement operation is to be carried out by remote operation, there is a problem that the band saw remote replacement operation is difficult because the band saw is not rigid and it is difficult to control this position and posture.

  Furthermore, since the material to be cut such as the reactor internal structure is activated, the chips generated at the time of cutting may be contaminated with radioactive substances. In the brush-type chip removal method used in the conventional band saw cutting device, there is a problem that the amount of radiation of the brush becomes high due to the chips adhering to the brush, and its handling is very difficult. .

 The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a band saw cutting apparatus for nuclear equipment and a cutting method thereof that can remotely replace the band saw.

 In order to achieve the above object, in the band saw cutting apparatus for nuclear equipment according to the present invention, a turntable on which the nuclear equipment is mounted and turned, a band saw unit for cutting the nuclear equipment mounted on the turntable with a band saw, A lifting carriage to which the band saw unit is detachably attached, and a vertical column that is attached to the lifting carriage so as to be lifted and installed in the vicinity of the nuclear equipment.

   Further, in order to achieve the above object, in the band saw replacement method for nuclear equipment according to the present invention, the nuclear equipment mounting process for mounting and turning the nuclear equipment on the turntable, and the cutting of the turned nuclear equipment mounted on the turntable A band saw positioning step of aligning the position of the band saw attached to the band saw unit at a location, a vertical cutting step of longitudinally cutting the nuclear equipment by switching the blade tip of the positioned band saw downward or upward, and the positioning of the positioned band saw A blade that detects blade wear by counting the number of blades passing through the blade saw when the band saw of the band saw unit is driven and the blade saw detecting sensor when the blade saw of the band saw unit is driven. The wear detection process and the loss of the band saw blade in this blade wear detection process A band saw unit detachably attaching a band saw unit band saw unit was replaced band saw that is not worn blade removed from lifting carriage has been detected, is characterized in that it has a.

  According to the present invention, since the replacement of the band saw can be performed remotely, it is possible to reduce the radiation exposure of employees accompanying the dismantling work of the nuclear equipment.

 DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a band saw cutting device for nuclear equipment and a cutting method thereof according to the present invention will be described below with reference to FIGS. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted.

 FIG. 1 is a front view showing a band saw cutting device for nuclear equipment according to an embodiment of the present invention, and FIG. 2 is a plan view showing a band saw cutting device for nuclear equipment according to an embodiment of the present invention.

 As shown in FIG.1 and FIG.2, the band saw cutting device 1 of a nuclear equipment has the turntable 3 which mounts the nuclear equipment 2 which is a to-be-cut material, and turns. The nuclear equipment 2 is made of a cylindrical material to be cut, is mounted on the turntable 3, and is mounted so as to be pivotable about the axis of the material 2 to be cut. As the material 2 to be cut, here, as an example, a nuclear reactor internal structure is assumed in the nuclear equipment. This nuclear reactor internal structure is designed to prevent the spread of radioactive material contamination and reduce the exposure of employees. It is carried out remotely underwater.

 In the vicinity of the nuclear equipment 2 that is the material to be cut, a vertical column 4 is erected at the bottom of the pool A of the reactor building.

 A linear bearing 5 is attached to the vertical column 4, and an elevating carriage 6 is disposed at the upper end of the linear bearing 5. The elevating carriage 6 can be moved in the vertical direction along the vertical column 4 by the elevating drive mechanism 7 installed on the elevating carriage 6.

 A clamp 9 that is actuated by an air cylinder 8 is disposed on the lift cart 6, and the band saw unit 10 is attached to the lift cart 6 by remote control by the clamp 9.

FIG. 3 is an enlarged front view showing the band saw unit 10 of FIG. 1, and FIG. 4 is an enlarged plan view showing the band saw unit 10 and the lift carriage 6 of FIG.
As shown in FIGS. 3 and 4, the band saw unit 10 has one drive reel 12 and three guide reels 13 arranged on a band saw unit frame 14. A band saw 11 is wound around these four reels 12 and 13.

 One of the guide reels 13 is provided with a tension adjusting screw 15, and the tension adjusting screw 15 can adjust the tension of the band saw 11.

 A hydraulic motor 16 is directly connected to the rear of the drive reel 12. The band saw 11 is configured to be rotated in a loop shape constituted by four reels 12 and 13 by the hydraulic motor 16 and counterclockwise in FIG.

 The band saw 11 has a structure capable of switching the blades of the band saw 11 downward (in some cases upward) and laterally in FIG. 3 by a band saw direction switching mechanism 18 operated by a drive motor 17. In other words, the band saw direction switching mechanism 18 can perform vertical cutting and horizontal cutting of the nuclear equipment 2 that is a workpiece. The nuclear equipment 2 is cut at an intermediate portion of the two band saw direction switching devices 18 provided.

 Chips adhere to the band saw 11 from which the nuclear equipment 2 has been cut, but the chips may be contaminated with radioactivity. When this cutting powder is caught inside the band saw unit 10, the radiation dose of the band saw unit 10 increases, and there is a high possibility that the employee cannot approach. Therefore, a chip removal nozzle 19 for injecting high-pressure water onto the band saw 11 is disposed immediately before being wound around the guide reel 13 after being cut. It has a structure in which the chips can be separated from the band saw 11 by the jet flow from the nozzle 19. Further, the chips separated from the workpiece 2 can be collected by a collection mechanism (not shown) including a suction device and a filter to prevent the chips from being scattered.

 As the cutting of the band saw 11 proceeds, the blade edge of the band saw 11 may be worn out or the cutting edge may be broken depending on the cutting conditions. A blade wear detection sensor 20 is arranged to detect this wear.

  5A and 5B are diagrams showing a schematic structure of the blade wear detection sensor according to the embodiment of the present invention, in which FIG. 5A is an enlarged plan view showing an X portion of FIG. 3, and FIG. 5B is a Y view of FIG. It is sectional drawing which cut | disconnects and shows the -Y arrow direction. As shown in FIGS. 5A and 5B, a proximity sensor is employed as the blade wear detection sensor 20. The blade wear detection sensor 20 is turned on when a sound cutting edge 21 passes when the band saw 11 is driven. As shown in the drawing, when the worn blade edge 22 passes through the sensor portion, the blade wear detection sensor 20 is not turned ON. The number of times that the blade wear detection sensor 20 is turned on while the band saw 11 makes one turn is counted by a control device (not shown), and the wear state of the band saw 11 can be detected by comparing with the number of sound blade edges.

 As described above, the band saw cutting device 1 for nuclear equipment includes a cutting band saw 11, a three guide reel 13 around which the band saw 11 is wound to form a loop of the band saw 11, and a drive for transmitting a rotational force to the band saw 11. The band saw unit 10 is configured by integrally attaching a hydraulic motor 16 for rotating the reel 12 and the drive reel 12 to form a cassette.

 As shown in FIG. 7, the band saw unit 10 configured in this way is positioned by positioning pins 24 that are positioning mechanisms provided in the lift cart 6. By remotely opening and closing the clamp 9, when the band saw 11 is worn out and replaced, the band saw unit 10 can be replaced by remote operation.

 In the present embodiment configured as described above, the turntable 3 is turned to position the longitudinal cutting position of the nuclear equipment 2 that is the material to be cut in accordance with the position of the band saw 11. With this vertical positioning, driving water is supplied to the hydraulic motor 16 shown in FIG. 4 to rotate the band saw 11. At this time, the cutting edge of the band saw 11 is set downward by the band saw direction switching mechanism 18. The lifting drive mechanism 7 lowers the lifting carriage 6 and the band saw unit 10 attached thereto to bring the band saw 11 and the work material 2 into contact with each other to start cutting. The cutting of the workpiece 2 proceeds, and before the upper side of the loop of the band saw 11 interferes with the upper side of the workpiece 2, the lowering of the band saw unit 10 is stopped, and the lifting cart 6 and the band saw unit 10 are once raised. By this work, one longitudinal cutting of the workpiece 2 can be performed.

 Of course, depending on the case, the cutting edge of the band saw 11 may be directed upward, and the band saw unit 10 may be raised to perform vertical cutting.

 Next, the turntable 3 is turned to position the workpiece 2 at the next longitudinal cutting position. After determining this vertical cutting position, the vertical cutting operation is repeated to complete one round. At the time of the last vertical cutting, the cutting edge of the band saw 11 is switched sideways by the band saw direction switching mechanism 18 without performing the ascending operation of the lifting cart 6 and the band saw unit 10 after the cutting is completed. In this state, the turntable 2 is turned while the band saw 11 continues to rotate, and the workpiece 2 is pressed against the blade edge of the band saw 11 facing sideways to perform horizontal cutting. By continuing the vertical cutting and the horizontal cutting, the workpiece 2 can be disassembled.

 As cutting progresses, the cutting edge of the band saw 11 is worn out. The wear state can be monitored by the blade wear detection sensor 20 shown in FIG. The number of sound cutting edges is not more than a predetermined number, that is, the number of rotations to be turned on is not more than a predetermined value. When the degree of wear set in advance is exceeded, it is displayed on a control device (not shown) so as to recommend replacement of the band saw 11. When exchanging the band saw 11, the rotation of the band saw 11 is stopped, and the band saw unit 10 is pulled up to a position where the workpiece 2 and the band saw 11 do not contact each other.

 In this state, the band saw unit 10 is hung by the overhead crane 23 of the reactor building shown in FIG. 6, the air cylinder 8 shown in FIG. 4 is extended in this state, the clamp 9 is opened, and the band saw unit 10 is removed from the lifting cart 6. Separate. The separated band saw unit 10 is pulled up on the water, and then gradually dyed, and then the employee loosens the tension adjusting screw 15 shown in FIG. 3 to relieve the tension of the band saw 11 to drive the drive reel 12 and the guide reel. The band saw 11 is removed from 13 and replaced with a new band saw 11.

 FIG. 7 shows a state after the band saw unit 10 is removed. Positioning pins 24 are arranged on the lifting carriage 6 for positioning the band saw unit 10. After exchanging the band saw 11, the band saw unit 10 is suspended so as to be fitted to the positioning pin 24, the air cylinder 8 is contracted, and the clamp 9 is tightened.

  FIG. 8 is a flowchart showing the procedure of the band saw cutting method for nuclear equipment according to the embodiment of the present invention.

 As shown in FIG. 8, in the nuclear equipment placement step S <b> 1, the nuclear equipment 2 that is a material to be cut is mounted on the turntable 3 installed at the bottom of the pool A of the nuclear reactor building and turned to perform positioning.

 In the band saw positioning step S2, the band saw 11 of the band saw unit 10 is positioned with respect to the nuclear equipment 2 mounted on the turntable 3.

 In the longitudinal cutting step S3, the nuclear equipment is longitudinally cut by the positioned band saw 11. At this time, the cutting edge of the band saw 11 is set downward by the band saw direction switching mechanism 18. The elevating drive mechanism 7 lowers the elevating carriage 6 and the band saw unit 10 attached thereto to bring the band saw 11 and the workpiece 2 into contact with each other and cut.

 In the transverse cutting step S4, the cutting edge of the band saw 11 is brought into contact with the vertically cut nuclear equipment 2 and further turned by the turntable 3 to transversely cut the nuclear equipment 2 and disassemble the nuclear equipment 2. At this time, the cutting edge of the band saw 11 is set sideways by the band saw direction switching mechanism 18.

 In the blade wear detection step S5, when the band saw 11 of the band saw unit 10 is cut, the blade wear detection sensor 20 counts the number of blades passing through the band saw 11 to detect blade wear.

  In the band saw unit attaching / detaching step S6, the band saw unit 10 in which the blade saw 11 has been replaced by removing the band saw unit 10 which has detected the blade wear of the band saw 11 in the blade wear detecting step S5 from the lifting cart 6 is attached. At this time, the band saw unit 10 is remotely attached to and detached from the lifting carriage 6 by opening and closing the clamp 9.

 According to the present embodiment, the worn state of the band saw can be detected remotely, and the band saw can be replaced remotely, so that it is possible to reduce the radiation exposure of employees accompanying the dismantling work of the nuclear equipment. .

  It is also possible to replace the band saw 11 by replacing the band saw 11 with the new band saw unit 10 without replacing the band saw 11 from the removed band saw unit 10.

 Further, in the band saw cutting apparatus 1, it is conceivable that the hydraulic motor 16 and the driving reel 12 can be separated by directly connecting the driving reel 12 and the hydraulic motor 16 and arranging a spline therebetween. In this case, the hydraulic motor 16 is rearranged from the band saw unit 10 to the lift cart 6. With the rearrangement of the hydraulic motor 16, the hydraulic motor 16 is not replaced when the band saw unit 10 is replaced.

  Depending on the present embodiment, the replacement of the band saw unit can be performed remotely and in a short time, so that it is possible to reduce the radiation exposure of the employee accompanying the dismantling work of the nuclear equipment.

The front view which shows the band saw cutting device of the nuclear equipment of embodiment of this invention. The top view which shows the band saw cutting device of the nuclear equipment of embodiment of this invention. The front view which expands and shows the band saw unit of FIG. The top view which expands and shows the band saw unit and raising / lowering cart of FIG. It is a figure which shows schematic structure of the blade wear detection sensor of embodiment of this invention, (A) is a front view which expands and shows the X section of FIG. 3, (B) is a YY arrow line view of FIG. 5 (A). FIG. The front view which shows the state during removal of the band saw unit in the band saw cutting device of FIG. The front view which shows the state which removed the band saw unit in the band saw cutting device of FIG. The flowchart which shows the procedure of the band saw cutting method of the nuclear equipment of embodiment of this invention.

Explanation of symbols

 DESCRIPTION OF SYMBOLS 1 ... Band saw cutting device, 2 ... Material to be cut (Nuclear equipment), 3 ... Turntable, 4 ... Vertical column, 5 ... Linear bearing, 6 ... Lifting carriage, 7 ..Elevating drive mechanism, 8 ... air cylinder, 9 ... clamp, 10 ... band saw unit, 11 ... band saw, 12 ... drive reel, 13 ... guide reel, 14 ... Band saw unit frame, 15 ... tension adjusting screw, 16 ... hydraulic motor, 17 ... drive motor, 18 ... band saw direction switching mechanism, 19 ... chip removal nozzle, 20 ... blade wear Detection sensor, 21 ... sound cutting edge, 22 ... worn edge, 23 ... overhead crane, 24 ... positioning pin.

Claims (13)

A turntable equipped with nuclear equipment and turning,
Band saw unit that cuts nuclear equipment mounted on this turntable with a band saw,
A lifting carriage that detachably attaches this band saw unit,
A vertical column that is installed in the vicinity of the nuclear equipment to attach the elevator cart so as to be movable up and down,
A band saw cutting device for nuclear equipment, characterized by comprising:  The band saw unit includes a plurality of guide reels wound around the band saw and formed in a loop shape, a drive reel that transmits a rotational force to the band saw, and a drive motor that rotates the drive reel. The apparatus for cutting a band saw of nuclear equipment according to claim 1.  The band saw cutting apparatus for a nuclear machine according to claim 1 or 2, wherein the band saw unit is provided with a band saw direction changing mechanism for switching a blade edge of the band saw in a vertical direction or a horizontal direction.  The said band saw unit is provided with the blade wear detection sensor which counts the number of passages of the blade of this band saw when the said band saw cut | disconnects the said nuclear equipment, and detects wear of a blade. A band saw cutting device for nuclear equipment according to any one of the above.  The band saw cutting device for a nuclear equipment according to any one of claims 1 to 4, wherein the band saw unit is provided with a chip removing nozzle for ejecting water for blowing off chips adhering to the band saw.  2. The nuclear equipment according to claim 1, wherein the lifting carriage includes a positioning mechanism for positioning the band saw unit, and a clamp mechanism for remotely attaching and detaching the band saw unit positioned by the positioning mechanism. Band saw cutting device.  The band saw unit includes a plurality of guide reels wound around the band saw and formed in a loop shape, and a drive reel that transmits a rotational force to the band saw by a drive motor provided in the lift carriage. The apparatus for cutting a band saw of nuclear equipment according to claim 1.   The band saw cutting device for a nuclear equipment according to claim 1, wherein the turntable and the vertical column are installed at the bottom of a pool of a reactor building. A nuclear equipment installation process in which nuclear equipment is mounted on a turntable and swiveled;
A band saw positioning step for aligning the position of the band saw attached to the band saw unit to the cutting position of the nuclear equipment swung on the turntable;
A longitudinal cutting step of longitudinally cutting the nuclear equipment by switching the blade tip of the positioned band saw downward or upward;
A transverse cutting step of transversely cutting the nuclear equipment by switching the blade edge of the positioned band saw to the lateral direction;
A blade wear detection step of detecting the blade wear by counting the number of passages of the blade of the band saw with a blade wear detection sensor when driving the band saw of the band saw unit;
A band saw unit attaching / detaching step of attaching a band saw unit that has been removed from the lifting carriage and replaced with a band saw that has not worn the blade, by detecting the wear of the band saw blade in this blade wear detecting step,
A method of cutting a band saw for nuclear equipment, comprising:   The nuclear saw band saw cutting method according to claim 9, wherein the vertical cutting step is to vertically lift and lower a lifting carriage to which the band saw unit is attached.   The nuclear saw band saw cutting method according to claim 9, wherein the transverse cutting step comprises turning a turntable on which the nuclear equipment is mounted to make a transverse cut.   10. The method of cutting a band saw for nuclear equipment according to claim 9, wherein the vertical cutting step and the horizontal cutting step are carried out in water stretched in a pool of a reactor building.   10. The method of cutting a band saw for nuclear equipment according to claim 9, wherein the step of attaching / detaching the band saw unit attaches / detaches the band saw unit to / from the lifting cart using an overhead crane.

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