JP2551793Y2 - Nozzle changing device for electric furnace - Google Patents

Description

[Detailed description of the invention]

[0001]

[Industrial application field] The present invention relates to an electric furnace,
The present invention relates to a device for exchanging a nozzle for injecting an inert gas or various powders into a molten metal.

[0002]

2. Description of the Related Art Conventionally, in an electric furnace in which an electrode is pushed into a furnace to dissolve and refine scraps, raw materials, metal materials, and the like by an arc, oxygen, an inert gas,
The molten metal is stirred by blowing powder or the like. The lance has a structure in which a lower end thereof is inserted through a working port provided in a furnace side wall so as to be immersed in the molten metal and blows oxygen, an inert gas, powder and the like into the molten metal. In recent years, it has been considered to provide a nozzle on the bottom side of the electric furnace and perform the blowing from the nozzle instead of performing the blowing operation of such oxygen, inert gas, powder, and the like by using a lance. . Therefore, in the case of such a nozzle structure, a device for attaching and detaching the nozzle from the bottom is required. For example, there is a device described in Japanese Utility Model Publication No. 4-2390 of the same applicant.

[0003] The outline of the invention is that a nozzle mounting / dismounting cylinder and a lifting / lowering cylinder for raising / lowering a supporting metal attached with the nozzle mounting / dismounting cylinder are provided for a nozzle opening in an electric furnace bottom, and the nozzle is opened. It has a centering mechanism that is set coaxially with the hole, and the centering mechanism is performed by fitting three posts provided in the furnace bottom and three posts provided in the exchange device. is there.

However, the exchange device according to the above-mentioned invention includes:
There are the following disadvantages. Since the centering of the nozzle with respect to the nozzle opening is performed by fitting the post receiver provided on the bottom of the electric furnace with the post provided on the replacement device side, it is necessary to work while moving the replacement device main body. It takes time for centering work. Since the post is provided for the nosle core, the workability under the furnace becomes worse when the nozzle is installed or replaced. The device body becomes large. Since the centering is performed by the post receiver provided on the furnace bottom, if the opening for the nozzle moves due to thermal expansion or the like during operation and the core is displaced from the steel, the nozzle may not be able to be inserted.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention solves the problems of the conventional apparatus, and provides a compact nozzle replacement apparatus which can smoothly perform the work of attaching and detaching the nozzle from below the electric furnace. Aim.

The nozzle changing device for an electric furnace according to the present invention is a nozzle changing device which can be moved up and down from immediately below an electric furnace to a nozzle opening provided at the bottom of the electric furnace. A lifting frame is provided on a tiltable frame that is tiltable, and a supporting base is provided on the lifting frame by being supported by a centering mechanism comprising a planar direction absorbing spring and a height direction absorbing spring. And a grip portion for the nozzle is formed at the tip of the rod of the detachable cylinder.

In the present invention, the work of aligning the gas injection nozzle with the opening for the nozzle provided in the bottom of the electric furnace is performed between a support base holding the nozzle and an elevating frame holding the support base. This is performed by the centering mechanism provided. If there is a misalignment in the direction perpendicular to the axis between the gas injection nozzle and the nozzle opening, the planar absorbing spring incorporated between the support base and the lifting frame displaces and absorbs the misalignment, and at the same time, in the height direction. The provided spring is also displaced in the direction perpendicular to the axis. The error absorption between the nozzle opening angle and the tilting frame angle is performed by simultaneously displacing the planar absorption spring and the height absorption spring. Even in the case where there are both the direction perpendicular to the axis and the angle error, the same operation as described above is performed at the same time, so that it can be absorbed. If there is no error, the displacement of the planar absorption spring does not occur, and the center of the lifting frame and the center of the support base are the same. As described above, the centering mechanism provided with the two types of absorption springs facilitates the work of centering the gas injection nozzle and the nozzle opening, and also facilitates the work of mounting and removing the nozzle. Becomes

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the present invention will be specifically described below based on embodiments. As shown mainly in FIG. 2, the furnace bottom of the electric furnace 1 is provided with a nozzle opening 4 that penetrates the iron shell 2 and the refractory 3 and communicates inside and outside the furnace. A nozzle 5 is attached to the nozzle opening 4, and the molten gas is stirred by blowing an inert gas from the outside through the nozzle 5. The nozzles 5 are periodically replaced due to erosion thereof, and this replacement operation is performed by a nozzle replacement device 6 set directly below or obliquely below the electric furnace 1. The nozzle changing device 6 is assembled on the table lifter 7, is set together with the table lifter 7 on the carriage 19 at the temporary storage space of the device, and is drawn under the electric furnace. In order to position the nozzle changing device 6 coaxially with the nozzle opening 4 provided in the furnace bottom of the electric furnace 1, the height is adjusted by the table lifter 7. The table lifter 7 and the nozzle changing device 6 are fixed by anchor bolts 8 and are integrated.

As shown in FIG. 3, the tilting frame 10 on the base 9 of the nozzle changing device 6 is connected to the base 9 by a tilt cylinder 12 so as to be tiltable about a tilt support pin 11. The tilting frame 10 is provided with lifting guides 14 of a lifting frame 13 on both sides, and supports a two-stage telescopic lifting cylinder 15 for driving the lifting frame 13. The lifting frame 13 is connected to a tip of a two-stage telescopic lifting cylinder 15 by a fixing pin 16. In FIG. 1, a support base 18 for supporting a nozzle mounting / dismounting cylinder 17 is supported on the lifting frame 13 by a plane-direction misalignment absorbing spring 20 and a height-direction absorbing spring 21. A set bolt 22 for restraining the degree of freedom δ by the planar direction absorbing spring 20 is provided between the lifting frame 13 and the support base 18.
3. A fixing hardware 23 is attached to the support base 18 when the nozzle is pulled out, and the nozzle attaching / detaching cylinder 17 is supported by a bracket 24 on the support base 18 and is rotatable. In addition, nozzle detachable cylinder 1
At the tip of 7, two couplings 2 for nozzle replacement
5 is installed.

In FIG. 4, a fixing hardware 26 is attached to the bottom of the electric furnace 1 when the nozzle is pulled out. The fixing hardware 23 of the support base 18 supported by the elevating frame 13 is inserted into pins 27 on both sides. And used when the nozzle is pulled out.

Next, the mounting operation of the nozzle 5 by the nozzle replacing device 6 having the above nozzle replacing mechanism will be described. First, as shown in FIG. 1, the nozzle 5 and the holding metal 28 to be newly mounted on the support base 18 are mounted using the mounting hardware 29 and the split coupling 25. Further, the set bolt 22 is tightened to restrict the degree of freedom δ between the lifting frame 13 and the support base 18. This work is performed by the nozzle changing device 6
Before taking it into the furnace.

Next, as shown in FIG. 2, the nozzle exchanging device 6 assembled on the table lifter 7 is
Is moved to the vicinity of the stop position under the electric furnace, and then the table lifter 7 is raised to the vicinity of the specified position and stopped. After roughly adjusting the angle of the tilting frame 10 to the mounting angle α of the nozzle opening 4 of the electric furnace 1 by the tilting cylinder 12, the two-stage telescopic lifting cylinder 15 for driving the lifting frame 13 is raised. The nozzle 5 keeps rising while maintaining the tilt angle. The opening 4 for the nozzle provided in the bottom of the electric furnace is often not maintained at the initial nozzle mounting angle α due to the operation of the electric furnace, and is often misaligned. As a result, FIG. Misalignment ε as shown
Appears as.

As shown in FIG. 1, with the nozzle 5 newly inserted into the nozzle opening 4 inserted to a certain extent, the misalignment ε between the nozzle opening 4 and the nozzle 5 is measured, and the misalignment degree of freedom δ is measured. ≧ After confirming that the misalignment amount ε of the nozzle to be mounted is satisfied, the set bolt 22 is loosened, and the elevating cylinder 15 continues to be raised. Here, if the set bolt 22 can be operated remotely, the operation is further facilitated. Since there is a misalignment ε from the nozzle opening 4, the nozzle 5 newly attached to one side of the nozzle opening 4 rises while being in contact with the nozzle opening 4. Height absorbing spring 21 between support 13 and support base 18
Due to this deformation, no excessive force is applied to the nozzle 5 and the nozzle 5 is smoothly inserted along the nozzle opening 4.

When the elevating cylinder 15 has been raised to the prescribed position, the nozzle mounting / dismounting cylinder 17 is then raised and completely inserted into the nozzle opening 4. When the mounting of the nozzle 5 is completed, the set bolt 22 is tightened to restrict the degree of freedom of the lifting frame 13 and the support base 18. The mounting of the nozzle 5 is completed by attaching the presser fitting 28 with a mounting bolt (not shown) on the furnace bottom, and further removing the coupling 25. When removing the damaged old nozzle, the lifting frame 13 is raised as shown in FIG. Are connected by inserting a pin 27 into the connector. The nozzle attaching / detaching cylinder 17 is raised, and the old nozzle and the nozzle attaching / detaching cylinder 17 are connected by a split coupling 25. Next, the nozzle attaching / detaching cylinder 17 is lowered, and the old nozzle is pulled out. Hereinafter, the operation is performed in a reverse manner to the nozzle mounting operation.

As described above, it is not necessary to accurately match the mounting angle α of the nozzle opening 4 in the furnace bottom of the electric furnace 1 and the misalignment ε of the nozzle to be mounted, and the centering operation time is greatly reduced. As a result, the replacement work can be performed in a short time.

[0016]

According to the present invention, there is provided a nozzle exchanging device which has a nozzle attaching / detaching mechanism which moves up or down directly below or diagonally below an electric furnace, and which is incorporated in an elevating frame which supports the nozzle attaching / detaching mechanism. The above structure absorbs misalignment in the upper, lower, left, and right directions, so that the nozzle can be smoothly mounted in the nozzle opening. Therefore, the centering work at the time of nozzle replacement is not required, so that the working time is shortened, the number of replacement staff is reduced, the operation rate of the electric furnace is improved, and the maintenance cost can be reduced. In addition, a compact exchange device can be obtained by incorporating the alignment mechanism in the lifting frame.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a centering mechanism of a nozzle replacement device according to the present embodiment.

FIG. 2 is a front view of the nozzle exchanging device when the nozzle exchanging device is disposed below an electric furnace.

FIG. 3 is an enlarged view of a main part of the nozzle replacement device.

FIG. 4 is a view showing a situation when the apparatus is set under an electric furnace.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric furnace 2 Iron shell 3 Refractory 4 Nozzle opening 5 Nozzle 6 Nozzle exchange device 7 Table lifter 8 Anchor bolt 9 Foundation base 10 Tilt frame 11 Tilt support pin 12 Tilt cylinder 13 Lift frame 14 Lift guide 15 Lift cylinder 16 Fixed Pin 17 Nozzle attachment / detachment cylinder 18 Support base 19 Dolly 20 Planar direction absorbing spring 1 21 Height direction absorbing spring 2 22 Set bolt 23 Fixing hardware 24 Bracket 25 Coupling 26 Fixing hardware 27 Pin 28 Holding hardware 29 Mounting hardware

Continued on the front page (72) Inventor Kiyosuke Mori 46-59 Ohara Nakahara, Tobata-ku, Kitakyushu-shi, Fukuoka Nippon Steel Corporation Machinery & Plant Business Department (72) Inventor Kenji Shirakawa Tobata-ku, Kitakyushu-shi, Fukuoka Oaza Nakahara 46-59 Nippon Steel Plant Design Co., Ltd. (56) References Japanese Utility Model Sho 63-186756 (JP, U) Japanese Utility Model Utility Model Hei 2-69952 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A nozzle exchanging device which is arranged to be able to ascend and descend from immediately below an electric furnace toward a nozzle opening provided in a furnace bottom of the electric furnace, wherein a vertically movable and tiltable tilting frame is provided. The lifting frame is supported by a centering mechanism composed of a plane-direction absorbing spring and a height-direction absorbing spring to provide a support base, and the support base is provided with a detachable cylinder of a nozzle, A nozzle changing device for an electric furnace, wherein a grip portion of a nozzle is formed at a rod tip portion.