JP5634335B2 - Lower tank replacement system and lower tank replacement method - Google Patents

Description

The present invention relates to a lower tank replacement system used when replacing a lower tank constituting a part of a vacuum degassing tank for refining molten steel, and a lower tank replacement method using the lower tank replacement system.

The molten steel that has undergone primary refining in the converter is subjected to degassing using a vacuum degassing apparatus for decarburization or for the purpose of removing dissolved gases such as hydrogen and nitrogen. In the degassing treatment, after the lower part (immersion tube) of the vacuum degassing tank is immersed in the molten steel in the pan, the air in the vacuum degassing tank is sucked so that the vacuum degassing tank is in a vacuum state. Thus, the molten steel is sucked into the vacuum degassing tank, and the gas components in the molten steel are released into the vacuum degassing tank.

A vacuum degassing tank such as an RH system is composed of a canopy, an upper tank, a lower tank, and a dip tube in order from the top, and these are connected by bolts. The lower tank of the vacuum degassing tank and the dip tube connected to it must be periodically removed from the upper tank and moved to the repair work place for replacement and repair. After connecting the tank to the upper tank, an operation of connecting a new dip tube to the lower tank is performed.

Regarding the technique for exchanging the lower tank of the vacuum degassing tank, for example, Patent Document 1 discloses an invention of a centering device used for exchanging the lower tank or dip tube of an RH vacuum degassing tank. This lower tank or dip tube centering device is installed on a lift that can move to a position directly below the mounting flange of the vacuum tank (vacuum degassing tank), a lift that can be moved up and down on the carriage by lifting means. And a slide table that holds the lower tank or the dip tube attached to the lower position of the vacuum tank in an upright state, and lateral movement means for moving the slide table in the front-rear and left-right directions.

Patent Document 2 discloses an invention of a lower tank replacement system and a lower tank replacement method for the purpose of replacing a lower tank of a vacuum degassing tank having a large-diameter dip tube having an open bottom surface. The lower tank replacement system is composed of a lower tank whose bottom surface is open and a lower tank replacement carriage for exchanging the lower tank. The upper outer periphery of the lower tank has a receiving portion facing the lower surface. Seats are provided at a plurality of locations. In addition, the lower tank replacement cart includes a main body that can travel on the traveling rail, a support table provided with an insertion support portion that is inserted into the receiving portion of each of the lower tank, and a base that supports the support table. It has a base part, a lifting device that is provided on the main body of the carriage and moves the base part up and down, and a moving mechanism that moves the support table in the front-rear and left-right directions with respect to the base part.

JP 2005-272889 A JP 2009-173981 A

However, the related art relating to the replacement of the lower tank of the vacuum degassing tank has the following problems.
As described above, the vacuum degassing tank is composed of a canopy, an upper tank, a lower tank, and a dip tube. For this reason, when replacing | exchanging a lower tank, after removing a dip tube, you have to remove a lower tank. And after performing the removal operation | work of the metal and slag adhering to an upper tank, it is necessary to attach a new lower tank to an upper tank, and to attach a dip pipe to a new lower tank. In the operation of removing the metal and slag adhering to the upper tank, the metal and slag are dropped by fusing or mechanically removing with oxygen supplied from an oxygen pipe such as a calorized pipe. At this time, the removed bullion and slag are collected by a bullion receiving box placed on the lifting platform of the centering device, instead of dropping on the ground for environmental considerations. However, since the lifting platform on which the bullion receiving box is placed is supported by the lifting cylinder, if the weight of the bullion and slag is large, the lifting cylinder is damaged due to the drop impact of the bullion and slag. It was.

Moreover, in the replacement | exchange operation | work of a lower tank, it is necessary to transport a lower tank to a repair place, and the lower tank is mounted and transported on a lower tank transfer stand. However, when the lower tank transfer platform on which the lower tank is placed is hung with a crane, a coil spring is interposed between the lower tank and the lower tank transfer platform, which makes the lower tank unstable and dangerous. Therefore, after temporarily placing the lower tank in another place and loading the lower tank transfer stand on the trailer, the lower tank is placed on the lower tank transfer stand. As a result, there are problems that the number of operations increases and a work space is required.

Furthermore, in the replacement work of the lower tank, it is necessary to replace the dip tube. However, since the two dip tubes must be replaced separately instead of simultaneously, the number of operations increases and the overall repair time is long. Become. As a result, the non-operating time has increased, which has been a factor in reducing the equipment operating rate.

The present invention has been made in view of such circumstances, and a lower tank replacement system in which a lifting cylinder is not damaged at the time of metal and slag removal work, and the efficiency of the replacement work of the lower tank and the reduction of human load can be reduced. It aims at providing the lower tank exchange method.

In order to achieve the above object, a first invention is a system for replacing a lower tank constituting a part of a vacuum degassing tank for refining molten steel,
(A) a carriage traveling on a track; an elevator frame that moves up and down on the carriage; a lift cylinder that detachably supports the elevator frame from below and lifts the elevator frame; and an elevator cylinder that is installed on the elevator frame A slide table that is movable in the front-rear and left-right directions, and a bullion collection box support means for supporting a bullion collection box used for removing bullion and slag attached to the upper tank of the vacuum degassing tank; A centering device having
(B) a dip tube transfer stand that can be set on the slide table and on which two dip tubes connected to the lower tank can be placed;
(C) a lower tank transfer stand that can be set on the slide table and on which the lower tank is placed;
(D) It has a suspension piece A for suspending the lower tank transfer gantry and a suspension piece B for suspending the lower tank on the lower tank transfer gantry. A hanging jig that can be suspended together with the lower tank is provided.

Moreover, 2nd invention is the method of replacing | exchanging the lower tank which comprises a part of vacuum degassing tank which refines molten steel using the lower tank exchange system which concerns on 1st invention, Comprising: I have.
(1) The dip tube transfer platform is set on the slide table, the centering device is moved below the vacuum degassing tank, and then the lifting platform is raised and connected to the lower tank. The two dip tubes are placed on the dip tube transfer platform, the two dip tubes are removed from the lower tank, the elevator frame is then lowered, and the centering device is removed from the vacuum degassing tank. A step of transferring the dip tube transfer platform on which the two dip tubes are mounted from the slide table after being moved;
(2) The lower tank transfer platform is set on the slide table, the centering device is moved below the vacuum degassing tank, the lifting platform is raised, and the lower tank is moved to the lower tank. The lower tank is placed on a transfer frame, the lower tank is removed from the upper tank of the vacuum degassing tank, the elevator frame is lowered, and the centering device is moved from the vacuum degassing tank. The process of transferring the said lower tank transfer stand by which it was mounted from the said slide table using the said hanging jig.
(3) The bullion collection box is placed on the lifting platform, the centering device is moved below the vacuum degassing tank, and then the lifting platform is raised to support the bullion collection box Set the means, collect the bullion and slag adhering to the upper tank in the bullion collection box, then store the bullion collection box support means to lower the lifting platform, the centering A step of moving the apparatus from the vacuum degassing tank and then transferring the metal collection box from the lifting platform.
(4) After setting the lower tank transfer platform on which a new lower tank is placed on the slide table using the hanging jig and moving the centering device below the vacuum degassing tank The new lower tank is moved up and down to bring the new lower tank closer to the upper tank, and the slide table is moved in the front-rear and left-right directions to position (center align) the new lower tank. After connecting a tank to the upper tank, then lowering the lifting platform and moving the centering device from the vacuum degassing tank, the lower tank transfer platform is moved from the slide table using the suspension jig. The process of transferring.
(5) After setting the dip tube transfer stand on which two new dip tubes are placed on the slide table, and moving the centering device below the vacuum degassing tank, the lift stand The new dip tube is moved closer to the new lower tank, the slide table is moved in the front / rear and left / right directions, and the new dip tube is positioned (centering). Connecting to the new lower tank, then lowering the lifting platform and moving the centering device from the vacuum degassing tank;

Further, in the lower tank replacement system according to the first invention, the bullion collection box support means includes a fixed support column erected on the carriage, the lifting platform on which the bullion collection box is placed, and the You may make it have a movable support | pillar made possible to interpose between a fixed support | pillar.

During the bullion and slag removal work, the lifting rack on which the bullion collection box is placed is raised, and a movable column is interposed between the lifting platform and the fixed column. Then, the rod of the elevating cylinder is lowered, the metal collection box is supported by the metal collection box support means via the elevating frame, and the elevating frame and the elevating cylinder are separated from each other. Thereby, the impact force of the bullion and the slag acting on the lifting platform is transmitted from the lifting platform to the fixed column via the movable column, and the impact force of the metal and slag does not act on the lifting cylinder.
On the other hand, when the bullion and slag removing operation is completed, the lifting platform is supported by the lifting cylinder and slightly lifted to separate the lifting platform from the movable support column. And a movable support | pillar is removed from between a raising / lowering stand and a fixed support | pillar, and a raising / lowering stand is lowered | hung with a raising / lowering cylinder.

Moreover, in the lower tank exchange system which concerns on 1st invention, it is suitable that the heat-resistant material is affixed on the lower surface of the said hanging jig.
Since the lower tank removed from the upper tank has high heat, the hanging jig may be deformed by the radiant heat radiated from the lower tank. Therefore, in the said structure, the deformation | transformation of a hanging jig | tool is prevented by sticking a heat-resistant material to the lower surface of a hanging jig | tool.

In the first and second inventions, since the bullion collection box supporting means for supporting the bullion collection box used for the bullion and slag removal work is provided, the impact force of the removed bullion and slag is raised and lowered. It does not act on the cylinder, and the elevating cylinder is not damaged by the drop impact of the metal and slag.
In addition, it has a suspension jig for suspending the lower tank transfer platform on which the lower tank is placed and a dip tube transfer platform on which two dip tubes can be placed. The tank replacement work is made efficient and the human load can be reduced.

It is the elevation which looked at the centering apparatus which comprises the lower tank exchange system which concerns on one embodiment of this invention from the advancing direction of this centering apparatus. It is AA arrow sectional drawing of FIG. It is an enlarged view of B site | part of FIG. It is the partial elevation which looked at the upper part of the same centering apparatus from the advancing orthogonal direction of this centering apparatus. (A) is a plan view of the bullion collection box support means at the time of storage, (B) is an elevation view of the bullion collection box support means viewed from the advancing direction of the centering device, (C) is the bullion collection. It is the elevation which looked at the box support means from the advancing orthogonal direction of the center alignment apparatus. (A) is a plan view of the bullion collection box support means at the time of setting, (B) is an elevation view of the bullion collection box support means viewed from the direction of travel of the centering device, (C) is the bullion collection. It is the elevation which looked at the box support means from the advancing orthogonal direction of the center alignment apparatus. (A) is the elevation which looked at the dip tube transfer stand from the advancing direction of the centering device, (B) is the elevation which looked at the dip tube transfer stand from the advancing orthogonal direction of the centering device. It is a top view of the base part, support member, and frame which are installed on the dip tube transfer stand. (A) is the elevation which looked at the lower tank transfer stand from the advancing direction of the centering apparatus, (B) is the elevation which looked at the lower tank transfer stand from the advancing orthogonal direction of the centering apparatus. It is a schematic diagram for demonstrating the lower tank replacement | exchange method which concerns on one embodiment of this invention. It is a schematic diagram for demonstrating the same lower tank exchange method. It is a schematic diagram for demonstrating the same lower tank exchange method. It is a schematic diagram for demonstrating the same lower tank exchange method.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention. In the following description, the traveling direction of the centering device is referred to as “front-rear” and the traveling orthogonal direction is referred to as “left-right”.

[Lower tank replacement system]
A lower tank replacement system according to an embodiment of the present invention includes a lower tank 51 (see FIG. 11) and a dip tube 52 (see FIG. 10) that constitute a part of a vacuum degassing tank (not shown) for refining molten steel. A centering device 10 (see FIG. 1), a dip tube transfer stand 31 (see FIG. 7) on which two dip tubes 52 connected to the lower tank 51 can be placed, and a lower tank The lower tank transfer pedestal 41 on which 51 is mounted, and a hanging jig 46 (see FIG. 9) that can be suspended in a state where the lower tank 51 is mounted on the lower tank transfer pedestal 41.

The alignment apparatus 10 is installed on a carriage 12 that travels on a rail 11 (an example of a track), an elevator base 16 that moves up and down on the carriage 12, an elevator cylinder 15 that raises and lowers the elevator base 16, and an elevator base 16. Supporting the bullion collection box 53 for supporting the bullion collection box 53 used for the removal of the slag and the slag attached to the upper tank 50 of the vacuum degassing tank and the slide table 18 movable in the front-rear and left-right directions And means 20 (see FIG. 13).

A pair of wheels 13 that are driven by a motor 14 installed on the carriage 12 and run on the rails 11 are attached to both sides of the front and rear parts of the carriage 12 that is rectangular in plan view. (See FIG. 1). The rail 11 is laid between a vacuum degassing tank and a repair site (exchange field), and the carriage 12 can be moved along the rail 11 to just below the vacuum degassing tank.

One lifting cylinder 15 is provided upright at the center of each of the front part and the rear part of the carriage 12. The elevating cylinder 15 is an electric cylinder, and a motor 24 for driving the elevating cylinder 15 is provided in the vicinity of each elevating cylinder 15 (see FIG. 10). The lifting cylinder 15 has a base end portion of the cylinder 15a fixed on the carriage 12, and the lifting platform 16 moves up and down when the rod 15b inserted in the cylinder 15a moves up and down.

The lifting platform 16 has a rectangular shape in plan view. The peripheral part of the lifting platform 16 is at a higher position than the central part, and is a work stage 19 on which an operator can place (see FIG. 4). On the lower surfaces of the central portions of the front and rear work stages 19, support portions 30 connected to the tip portions of the rods 15 b of the elevating cylinder 15 are installed. The support portion 30 is formed with a recessed portion that fits with the tip of the spherical rod 15b. The tip of the rod 15b of the elevating cylinder 15 is movable in the vertical direction within the recessed portion of the support portion 30, and is detachable from the support portion 30.

As shown in FIG. 2, fixed pillars 25 made up of box pillars are installed at the four corners of the carriage 12. Each fixed column 25 is arranged so that the long side surface is parallel to the diagonal direction of the carriage 12. Further, an elevating frame 17 made of H-shaped steel extending downward from the elevating frame 16 is disposed inside each fixed support 25 in plan view. Each lifting frame 17 is disposed such that one flange faces one short side surface of the fixed support 25 (see FIG. 3). A roller 26 is attached to the flange surface of the elevating frame 17 facing the short side surface of the fixed column 25, and the roller 26 is guided to the short side surface of the fixed column 25 facing the flange surface. A guide rail 27 is installed in the material axis direction of the fixed column 25. Thereby, the lifting platform 16 can be moved up and down stably.

The slide table 18 has a rectangular shape in plan view, and is installed on the lifting platform 16 via cross slide guides 28 arranged at four corners (see FIG. 4). The cross slide guide 28 includes an upper rail 28a and a lower rail 28b that are orthogonal to each other in plan view, and a sliding portion 28c that travels along the upper rail 28a and the lower rail 28b. The upper rail 28 a is fixed to the slide table 18, and the lower rail 28 b is fixed to the lifting platform 16.

Further, a positioning pin 18b is formed on the upper surface of the slide table 18 so as to project upward from the upper surface and set a dip tube transfer frame 31 and an adapter 40 (see FIG. 11) described later (see FIG. 4). . On the other hand, on the lower surface of the slide table 18, a protrusion 18 a that protrudes downward from the lower surface is formed. One protrusion 18a is disposed at each of the front, rear, right, and left of the slide table 18, and a hydraulic cylinder 29 for pressing the protrusion 18a in the horizontal direction is provided adjacent to each protrusion 18a. It is installed on the lifting platform 16.
When moving the slide table 18 in the front / rear / right / left direction, the rods of all the hydraulic cylinders 29 are retracted to the last retreat, and the hydraulic oil is fed only to the hydraulic cylinders 29 in the moving direction, and slides in a predetermined direction. The table 18 is moved (inching). When the movement of the slide table 18 is finished, the corresponding hydraulic cylinders 29 are pressed against the protrusions 18a. If necessary, the valves of all the hydraulic cylinders 29 are closed to lock the movement of the slide table 18.

FIGS. 5A, 5B, and 5C show the state of the bullion collection box support means 20 at the time of storage, and FIGS. 6A, 6B, and 6C show the ground at the time of setting (operation). The state of the gold collection box support means 20 is shown respectively. The bullion collection box support means 20 is erected on the carriage 12 and a rod-like member 22 that extends downward from the lifting platform 16, a movable column 21 that is connected to the rod-like member 22 by a hinge 23, and that rotates in a horizontal plane. It is comprised roughly from the fixed support | pillar 25. FIG. The movable support column 21 is provided with an operation handle 21a for rotating the movable support column 21, and the rod-like member 22 is provided with a fastener 22a for storing the operation handle 21a.

When setting the bullion collection box support means 20, after raising the lifting platform 16, the operator rotates the movable column 21 by 90 ° with the operation handle 21 a, and between the lifting platform 16 and the fixed column 25. A movable support 21 is interposed between the two. Then, the rod 15b of the elevating cylinder 15 is lowered.
On the other hand, when storing the bullion collection box support means 20, the rod 15b of the elevating cylinder 15 is raised, the elevating gantry 16 is supported and the elevating gantry 16 is slightly raised, and the elevating gantry 16 and the movable support column 21 are connected. Separate. Then, after the operator rotates the movable column 21 by 90 ° with the operation handle 21a and removes the movable column 21 from between the lifting platform 16 and the fixed column 25, the fastener 22a is prevented so that the movable column 21 does not move. The movable support 21 is restrained by

The dip tube transfer stand 31 is schematically configured from a transfer stand 32 that is rectangular in plan view, and two dip tubes 52 can be placed thereon (see FIGS. 7A and 7B). . On the transfer table 32, two rectangular base portions 35 are installed in plan view (see FIG. 8). Support members 36 for supporting the dip tube 52 are erected at the four corners of each base 35, and the four support members 36 are integrated with a substantially octagonal frame 37 in plan view (see FIG. 8). A coil spring 36a for elastically supporting the dip tube 52 is built in the upper part of each support member 36. When the dip tube 52 is attached to the lower tank 51, the dip tube flange (not shown) is applied by the biasing force of the coil spring 36a. And a lower tank flange (not shown) are secured.
Further, the four corners of the transfer table 32 are suspension parts 33, and a suspension piece 34 for attaching a wire 38 used when the immersion pipe transfer table 31 is suspended by the crane hook 39 is provided at the tip of the suspension part 33. Welded. Note that a positioning hole 32 a into which a positioning pin 18 b formed on the slide table 18 is inserted is formed on the lower surface of the transfer table 32.
In addition, since the dip tube 52 mounted on the dip tube transfer pedestal 31 has high heat, it is preferable to provide a glass wool layer on the upper surface of the base portion 35.

The lower tank transfer stand 41 is schematically configured from a transfer stand 42 that is rectangular in plan view. The four corners of the transfer table 42 are suspension parts 43, and a suspension piece 44 for attaching a wire is welded to the tip of the suspension part 43 (see FIGS. 9A and 9B). A plurality of coil springs 45 (4 × 2 rows) for elastically supporting the lower tank 51 are disposed on the transfer table 42, and when the lower tank 51 is attached to the upper tank 50, the urging force of the coil spring 45 is provided. Thus, the adhesiveness between the lower tank flange (not shown) and the upper tank flange is ensured. On the other hand, a positioning hole 42 a is formed on the lower surface of the transfer table 42, and the transfer table 42 is fixed by positioning pins 40 b provided on the upper surface of the adapter 40.
In addition, since the lower tank 51 mounted on the lower tank transfer stand 41 is high in temperature, it is preferable to provide a glass wool layer on the upper surface of the transfer table 42.

The suspension jig 46 has a substantially cross beam shape in plan view, and includes a long beam 46a and a short beam 46b. A suspension piece A47a for suspending the lower tank transfer platform 41 is provided at both ends of each long beam 46a, and a lower tank 51 on the lower tank transfer platform 41 is suspended at one end of each short beam 46b. The suspension pieces B47b are joined to each other. A lifting portion 48 for lifting the lifting jig 46 with a crane hook 39 is formed at the center of gravity of the hanging jig 46. Furthermore, a heat-resistant plate 49 made of glass wool (an example of a heat-resistant material) is installed on the lower surfaces of the long beam 46a and the short beam 46b so that the hanging jig 46 is not deformed by the radiant heat radiated from the lower tank 51. ing.

[Lower tank replacement method]
Next, a method of replacing the lower tank 51 using the lower tank replacement system having the above configuration will be described.

(1-1) The dip tube transfer stand 31 was set on the slide table 18 with a crane (not shown) (the positioning pins 18b of the slide table 18 were inserted into the positioning holes 32a formed on the lower surface of the dip tube transfer stand 31). Thereafter, the centering device 10 is moved below the vacuum degassing tank (see FIG. 10).
(1-2) The elevating cylinder 15 is driven to raise the elevating frame 16, and the two dip tubes 52 connected to the lower tank 51 are placed on the dip tube transfer frame 31.
(1-3) Remove the two dip tubes 52 from the lower tank 51.
(1-4) After the elevating cylinder 15 is driven and the elevating platform 16 is lowered, the centering device 10 is moved from the vacuum degassing tank.
(1-5) The dip tube transfer platform 31 on which the two dip tubes 52 are placed is lifted by a crane and transferred from the slide table 18 to the repair site.

(2-1) After the height adjustment adapter 40 is set on the slide table 18 (the positioning pins 18b of the slide table 18 are inserted into the positioning holes 40a formed on the lower surface of the adapter 40), the lower tank transfer stand 41 Is set on the adapter 40 by a crane using the lifting jig 46 (see FIG. 11). And the center alignment apparatus 10 is moved below a vacuum degassing tank.
(2-2) The elevating cylinder 15 is driven to raise the elevating frame 16 and the lower tank 51 is placed on the lower tank transfer frame 41.
(2-3) Remove the lower tank 51 from the upper tank 50 of the vacuum degassing tank.
(2-4) After driving the elevating cylinder 15 and lowering the elevating frame 16, the centering device 10 is moved from the vacuum degassing tank.
(2-5) The lower tank transfer platform 41 on which the lower tank 51 is placed is lifted by a crane using the lifting jig 46 and transferred from the adapter 40 to the repair site. Next, the adapter 40 is removed from the slide table 18.

(3-1) The bullion collection box pedestal 54 is set on the lifting platform 16 so as to straddle the slide table 18 with the leg portion 54a of the bullion collection box pedestal 54 (see FIG. 12). Then, the bullion collection box 53 is placed on the bullion collection box frame 54.
(3-2) After moving the centering device 10 below the vacuum degassing tank, the lifting cylinder 15 is driven to lift the lifting platform 16.
(3-3) The movable support column 21 is rotated by the operation handle 21 a, the movable support column 21 is interposed between the lifting platform 16 and the fixed support column 25, and the rod 15 b of the lifting cylinder 15 is lowered to lower the metal The collection box support means 20 is set (see FIG. 13).
(3-4) The metal and slag adhering to the upper tank 50 are collected in the metal collection box 53.
(3-5) The lifting platform 16 is supported by the lifting cylinder 15 to slightly lift the lifting platform 16 and the lifting platform 16 and the movable column 21 are separated from each other. Then, the movable support column 21 is rotated by the operation handle 21 a, the movable support column 21 is removed from between the lifting platform 16 and the fixed support column 25, and the metal collection box support means 20 is stored.
(3-6) After driving the elevating cylinder 15 and lowering the elevating frame 16, the centering device 10 is moved from the vacuum degassing tank.
(3-7) Remove the bullion collection box 53 and the bullion collection box frame 54 from the lifting frame 16.

(4-1) After the height adjusting adapter 40 is set on the slide table 18, the lower tank transfer platform 41 on which the new lower tank 51 is placed is placed on the adapter 40 by the crane using the lifting jig 46. Set to. And the center alignment apparatus 10 is moved below a vacuum degassing tank.
(4-2) The elevating cylinder 15 is driven to raise the elevating gantry 16 so that the new lower tank 51 approaches the upper tank 50.
(4-3) The hydraulic cylinder 29 is driven to move the slide table 18 in the front-rear and left-right directions, and after positioning (centering) the new lower tank 51, the new lower tank 51 is connected to the upper tank 50. To do.
(4-4) After the elevating cylinder 15 is driven and the elevating stand 16 is lowered, the centering device 10 is moved from the vacuum degassing tank.
(4-5) Remove the lower tank transfer platform 41 from the adapter 40 using the lifting jig 46 and then remove the adapter 40 from the slide table 18.

(5-1) After setting the dip tube transfer stand 31 on which two new dip tubes 52 are placed on the slide table 18 by a crane, the centering device 10 is moved below the vacuum degassing tank.
(5-2) The elevating cylinder 15 is driven to raise the elevating gantry 16 to bring the new dip tube 52 closer to the new lower tank 51.
(5-3) After the hydraulic cylinder 29 is driven to move the slide table 18 in the front-rear and left-right directions to position the new dip tube 52 (center alignment), a new dip is made in the lower tank 51 connected earlier. Connect the tube 52.
(5-4) After driving the elevating cylinder 15 and lowering the elevating platform 16, the centering device 10 is moved from the vacuum degassing tank.

Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations described in the above-described embodiments, and is considered within the scope of the matters described in the claims. Other embodiments and modifications are also included. For example, in the above embodiment, an electric cylinder is used as the elevating cylinder, but a hydraulic cylinder may be used. Moreover, in the said embodiment, although the lower tank replacement | exchange system is used for replacement | exchange of a lower tank, it cannot be overemphasized that a lower tank replacement | exchange system can be used only in replacement | exchange of a dip tube.

10: alignment device, 11: rail (track), 12: carriage, 13: wheel, 14: motor, 15: lifting cylinder, 15a: cylinder, 15b: rod, 16: lifting platform, 17: lifting frame, 18: Slide table, 18a: protrusion, 18b: positioning pin, 19: work stage, 20: bullion collection box support means, 21: movable support, 21a: operation handle, 22: rod-shaped member, 22a: fastener, 23: hinge , 24: motor, 25: fixed support, 26: roller, 27: guide rail, 28: cross slide guide, 28a: upper rail, 28b: lower rail, 28c: sliding part, 29: hydraulic cylinder, 30: bearing part , 31: dip tube transfer stand, 32: transfer stand, 32a: positioning hole, 33: suspension part, 34: suspension piece, 35: base part, 36: support part 36a: Coil spring, 37: Frame, 38: Wire (strand), 39: Crane hook, 40: Adapter, 40a: Positioning hole, 40b: Positioning pin, 41: Lower tank transfer stand, 42: Transfer stand, 42a: Positioning hole, 43: Suspension part, 44: Suspension piece, 45: Coil spring, 46: Suspension jig, 46a: Long beam, 46b: Short beam, 47a: Suspension piece A, 47b: Suspension piece B, 48: Lifting Part: 49: heat-resistant plate, 50: upper tank, 51: lower tank, 52: dip tube, 53: bullion collection box, 54: bullion collection box mount, 54a: leg

Claims (4)

A system for replacing a lower tank constituting a part of a vacuum degassing tank for refining molten steel,
(A) a carriage traveling on a track; an elevator frame that moves up and down on the carriage; a lift cylinder that detachably supports the elevator frame from below and lifts the elevator frame; and an elevator cylinder that is installed on the elevator frame A slide table that is movable in the front-rear and left-right directions, and a bullion collection box support means for supporting a bullion collection box used for removing bullion and slag attached to the upper tank of the vacuum degassing tank; A centering device having
(B) a dip tube transfer stand that can be set on the slide table and on which two dip tubes connected to the lower tank can be placed;
(C) a lower tank transfer stand that can be set on the slide table and on which the lower tank is placed;
(D) It has a suspension piece A for suspending the lower tank transfer gantry and a suspension piece B for suspending the lower tank on the lower tank transfer gantry. A lower tank replacement system comprising a hanging jig that can be suspended together with the lower tank. 2. The lower tank replacement system according to claim 1, wherein the bullion recovery box support means includes a fixed support column erected on the carriage, the lifting platform on which the bullion recovery box is placed, and the fixed support column. A lower tank exchange system characterized by having a movable support that can be interposed between the two. 3. The lower tank replacement system according to claim 1, wherein a heat resistant material is attached to a lower surface of the hanging jig. 4. A method for exchanging a lower tank constituting a part of a vacuum degassing tank for refining molten steel, using the lower tank exchange system according to any one of claims 1 to 3,
The dip tube transfer platform is set on the slide table, and the centering device is moved below the vacuum degassing tank, and then the lifting platform is lifted and connected to the lower tank. The dip tube was placed on the dip tube transfer pedestal, the two dip tubes were removed from the lower tank, the elevating pedestal was lowered, and the centering device was moved from the vacuum degassing tank. Then, the step of transferring the dip tube transfer platform on which the two dip tubes are placed from the slide table;
After the lower tank transfer platform is set on the slide table and the centering device is moved below the vacuum degassing tank, the lifting platform is raised, and the lower tank is moved onto the lower tank transfer platform. After removing the lower tank from the upper tank of the vacuum degassing tank, lowering the lifting platform and moving the centering device from the vacuum degassing tank, the lower tank is placed Transferring the lower tank transfer platform made from the slide table using the suspension jig;
The bullion collection box is placed on the lifting platform, the centering device is moved below the vacuum degassing tank, the lifting platform is raised, and the bullion collection box support means is set. And collecting the bullion and slag adhering to the upper tank in the bullion collection box, then storing the bullion collection box support means and lowering the lifting platform, After moving from the vacuum degassing tank, transferring the metal recovery box from the lifting rack;
The lower tank transfer platform on which a new lower tank is placed is set on the slide table using the suspension jig, the centering device is moved below the vacuum degassing tank, and then the lifting / lowering is performed. Raise the gantry to bring the new lower tank closer to the upper tank, move the slide table in the front / rear and left / right directions to position the new lower tank, and connect the new lower tank to the upper tank And then lowering the lifting platform, moving the centering device from the vacuum degassing tank, and then transferring the lower tank transfer platform from the slide table using the suspension jig;
The dip tube transfer platform on which two new dip tubes are placed is set on the slide table, the centering device is moved below the vacuum degassing tank, and then the lift platform is raised. The new dip tube is moved closer to the new lower tub, and the slide table is moved in the front-rear and left-right directions to position the new dip tube and connect the new dip tube to the new lower tub. And then lowering the lifting platform and moving the centering device from the vacuum degassing tank.

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