JPH0126756Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a lance feeding device for an electric furnace for steelmaking. This relates to a device that sequentially feeds long lances into molten steel.

[Prior art]

Scrap and other materials charged into an electric furnace for steelmaking are refined by the electric arc emitted from the electrodes. Oxygen is injected. Further, carbon powder is also supplied as necessary for carburization and reduction of iron oxide in the slag.
Oxygen is blown in alone and carbon powder is blown in together with conveying air, and for this purpose a long iron pipe lance with special ceramic treatment on the inside and outside is used. Electric furnaces are usually equipped with a slag discharge port on the side of the furnace body, and during refining, for example, the diameter is 30mm and the length is 5m.
The lance is inserted into the molten steel from the slag discharge port. The tip of the lance will melt and wear away while spewing out oxygen and carbon powder, so it is necessary to insert it further to cover the length of the lance that has been consumed.

If this is done manually, the workers will be forced to do hard work under high heat, so a feeding means such as a hydraulic cylinder or an air cylinder is used. However, the amount of extension of the cylinder is limited, so short lances must be used and frequently replaced or added. Moreover, it is necessary to grasp the lance again each time, and the work and blowing are forced to be interrupted. Therefore, recently, a lance feeding device has been adopted in which a lance is connected in advance to make it long, and the lance is held and fed by a pinch roller. According to this, the lance is pushed into the slag discharge port by pressing the lance with the driven upper roller and driving the lower roller on which the lance rests, and simultaneously tilting the upper roller support and the lower roller support. By doing so, the insertion posture of the lance can be changed. By feeding with rollers, there are no restrictions on the amount of feed, and even if re-gripping is required, it is extremely easy to do so, and the desired blowing can be performed continuously.

[Problem that the invention attempts to solve]

By the way, one lance is, for example, 5 m long, and the tips of the two lances are butted against each other and connected by a joint. The lance can be easily connected by caulking the fitting, but since the fitting is attached to cover the tip of the lance, the diameter of the fitting inevitably becomes larger than the diameter of the lance. Therefore, when the lance is held between pinch rollers and fed, the joint portion obstructs the passage of the rollers. For this purpose, as shown in FIG. 6, there is a device in which upper rollers 4a and 4b are elastically supported so as to be able to move up and down independently. According to this, when the joint part 22 passes each roller, even if the lower roller 5 driven to send the lance 3 is installed so as not to be able to be displaced, one of the upper rollers 4 escapes upward and the joint part 22 passes through each roller. 22 is allowed to pass. Of course, the lance 3 is pressed by the lower roller 5 and receives a feeding force, and is moved in the desired direction of the arrow 38.

The pressure of the lance 3 against the lower roller 5 by the upper roller 4 described above is required to be as uniform as possible. This is because although the lower roller is used to feed the lance 3, if the lower roller 5 and the lance 3 are not in good contact, the lance 3 will not be able to be fed at the desired speed. As shown in FIG. 7, when the joint portion 22 is on any of the lower rollers 5, for example 5A, the upper roller 4 located near it
a rises greatly, and the upper roller 4b does not rise or rises only a very small amount. The force with which the upper roller 4 presses the lance 3 against the lower roller 5 is proportional to the amount of compression of the pressure spring 27a, so the pressing force of the upper roller 4a is greater than that of the upper roller 4b, and the lance 3 is pressed with an even force. It is no longer pressed by the lower roller 5. If the contact friction forces between the lower roller 5 and the lance 3 are different, the lance 3 will not move smoothly and sufficient propulsive force will not be obtained.

Therefore, even if the desired feed speed is controlled, the lance may not move at that speed.
There is a problem with problems such as problems with oxygen injection. Furthermore, when the joint approaches the roller, the elastic force of the pressure spring 27a in the vicinity increases, so a large feeding force is required to pass through the joint, and assistance such as pushing a lance is required. A number of workers must be assigned. Alternatively, the roller must be made larger in order to increase the driving force of the lower roller or to widen the contact surface between the roller and the lance, which poses a problem of increasing the size of the device and increasing manufacturing costs.

The present invention was devised to solve the above-mentioned problem, and its purpose is to evenly press a long, thin lance with a joint part with an upper roller, without increasing the size of the device, so that the lower To provide a lance feeding device for an electric furnace for steelmaking, which can reliably feed with rollers and exhibit sufficient propulsive force.

[Means for solving problems]

The features of the lance feeding device for an electric furnace for steelmaking according to the present invention will be explained with reference to FIG. This is a lance feeding device in which the lance 3 is fed and the posture of the lance 3 can be changed by tilting the upper roller support 7 and the lower roller support 8, the upper roller support being 7 has a balance support structure 7A and a bogie structure 7B, the upper roller 4 is supported in a bogie format, and the bogie structure 7B equipped with two pairs of bogies 23 changes its posture to the balance support structure 7A. A pressurizing spring 27 is provided at the upper center of the balance support structure 7A, and the bogie structure 7B
7 toward the lower roller support 8;
Both ends of the balance support structure 7A are supported by one end side of a "dogleg" lever 25 whose center portion is supported by the lower roller support 8, and the other end of the "dogleg" lever 25 The sides are connected by a connecting rod 34, and the connecting rod 34 is connected to a push/pull mechanism 35.

[Effect]

When the push/pull mechanism 35 is operated, the dogleg lever 25 moves together with the connecting rod 34, and the balance support structure 7A rises while maintaining its posture. The upper roller 4 is separated from the lower roller 5, and a new lance 3 can be mounted on the lower roller 5, or the old lance 3 that has become short due to wear and tear can be removed.
The push/pull mechanism 35 is reversely operated to lower the upper roller 4, and a new lance 3 is held between the lower roller 5 and the upper roller 4. By driving the lower roller 5, when the joint portion 22, which is thicker than the lance diameter for connecting the lance 3, comes directly under one of the upper rollers, one of the rollers supported in a bogie type connects to the joint. It appears as though the other part is placed on top of the joint part 22 and removed from the joint part 22. At this time, the bogie 23 is tilted, but the support point of the bogie 23 is raised by only half the height up to the shaft support point of the upper roller 4 raised by the joint portion 22. As a result, the increase in the pressing force by the pressure spring 27 is reduced, and all upper rollers 4 apply the same pressing force to the lance 3 evenly and to the same extent as before.

[Effect of idea]

The upper roller is supported in the form of a bogie, and the bogie structure is attached to the balance support structure by hanging down so that its posture can be changed freely.The balance support structure has a pressure spring in the upper center, and the bogie structure supports the lower roller. Since it is biased toward the support, when the joint is located on the upper roller, the upper roller is displaced to allow the joint to pass, and the lance is equally pressed by all the upper rollers. The lance is reliably fed by the lower roller. Therefore, the necessary driving force to feed the molten steel can always be applied to the lance, and even if the feed rate must be precisely controlled, the lance can be given that speed to perform operations such as oxygen blowing. Desired work is facilitated. Further, the push-pull mechanism allows the balance support structure to be easily raised and the upper roller to be separated from the lower roller, making it easy to replace or remove the lance.

〔Example〕

Hereinafter, the present invention will be described in detail based on examples thereof. FIG. 2 shows the lance 3 being fed into the electric furnace 2 by the lance feeding device 1, with the lance 3 being held between a plurality of rollers 4 and 5 arranged on the upper and lower sides, and the lower roller 5 being fed into the electric furnace 2. By driving, the lance 3 is sent to the molten steel 6 through the slag discharge port 2a of the electric furnace 2. The above-mentioned upper roller 4 and lower roller 5 are supported by an upper roller support 7 and a lower roller support 8, respectively, and although not shown in detail, by operating a hydraulic cylinder 9, etc., the upper roller 4 and the lower roller 5 are The roller support 7 and the lower roller support 8 can be integrally tilted about a fulcrum 10 as partially shown by imaginary lines.
The tilting angle can be up to about 20 degrees, and the position of the tip of the lance 3 can be easily changed when cutting scrap. The lance feeder 1 as described above is mounted on a truck 11 so that it can be evacuated from the electric furnace 2 along a track 12 and can approach the slag discharge port 2a.

Figure 1 is a diagram of the main parts of the lance feeding device of the present invention.
A sprocket 13 is attached to each of the lower rollers 5, and a chain 14 is connected to it via an idler and a tensioner. The rotation of the motor 15 is transmitted from the drive sprocket 16 to each sprocket 13, and the lower roller 5, which feeds the lance 3 directly, is driven in a desired direction. The lower roller 5 and the upper roller 4 have an hourglass shape for holding the lance 3 having a circular cross section, and each is supported by a bearing (not shown). The sprocket 13 described above is integrated with the side surface of the lower roller 5, and does not obstruct passage of the lance 3.

Although there are four such lower rollers 5 in the illustration, the number can be selected arbitrarily, and usually three or more are provided. All or part of the lower roller 5 is elastically supported in the vertical direction by a spring 17. In this example, the central two rollers 5B and 5C among the four lower rollers 5 are supported by a swinging arm 18, one end of which is rotatably attached to a support base 19, and the other end of the swinging arm 18 is rotatably attached to a support base 19. A coiled spring 17 is interposed between the lower roller support member 8 and the upper surface of the lower roller support member 8 . The spring 17 is fitted onto a rod 20 hanging from the swing arm 18, and the lower end of the rod 20 is connected to the lower roller support 8.
The lower roller 5 is inserted into a space 21 formed therein, and is regulated by a retainer 20a so that the lower roller 5 does not rise excessively. On the other hand, the lower roller 5A,
5D is said to have an immovable support point. According to the lower roller 5 installed in this way, when the joint part 22 of the lance 3 passes the lower roller 5B or 5C, the lower roller descends, and when it passes the lower roller 5A or 5D, The lower rollers 5B and 5C rise so as to come into contact with the lower surface of the lance 3, which is slightly raised. Therefore, the lance 3 can be constantly driven to be fed by the support of the four lower rollers 5.

A driven upper roller 4 for holding down the lance 3 is supported above the lower roller support 8, and the joint portion 22 of the lance 3 is connected to the lower roller 5A,
When passing the upper rollers 4A to 4D and the lower roller 5D, the upper roller 4 located near the joint portion 22 is configured to be displaced upward to allow the joint portion 22 to pass. Therefore, the upper roller 4 is supported in a bogie manner, and the two pairs of bogies 2
3 is attached to the bogie structure 7B. Specifically, the upper roller support 7 has a balance support structure 7A and a bogie structure 7B, and the balance support structure 7A has a column 24 rising from the front and rear ends of the lower roller support 8. It is installed so as to be movable up and down in a direction away from the lower roller support 8 via a lever 25 . A bogie structure 7B is attached to the balance support structure 7A via a hanger 26 so as to be able to change its posture freely, and one or more pressurizing springs 27 are provided at the upper center of the bogie structure 7B. As a result, the bogie structure 7B is always urged toward the lower roller support 8. As shown in the figure, upper rollers 4A and 4B are supported by one bogie, upper rollers 4C and 4D are supported by another bogie, and these two pairs of bogies 23 are provided on bogie structure 7B. As a result, the upper rollers 4 are all biased by one pressure spring 27, making it possible to make the pressing force acting on each upper roller more uniform than in the case where a pressure spring is provided for each upper roller. can. A stopper 28 is provided to prevent the upper roller 4 from tilting significantly at the lower end of the bogie structure 7B, and the pressure spring 27 is built into a spring box 29 formed in the balance support structure 7A. The pressing force can be adjusted using a bolt 30.

A swing lever 31 is provided on the upper roller support 7 to prevent the bogie structure 7B from shifting in the moving direction of the lance 3. Bogie structure 7
B must be able to be displaced downward as a whole in order to press the lance 3, and when the joint portion 22 passes through one of the upper rollers 4, it must be able to be tilted to allow upward displacement of only that roller. There must be. Therefore, the bogie structure 7B
It is simply suspended. The balance support structure 7A is designed to be able to fix its position as will be described later, but the swing lever 31 that prevents the bogie structure 7B from shifting is rotatably supported by the balance support structure 7A. , its end in the lance feeding direction is attached to a bracket 32 extending downward from the bogie structure 7B while maintaining a substantially horizontal posture.

By the way, in order to facilitate the removal or gripping of the lance 3 held between the upper roller 4 and the lower roller 5 from the lance feeding device, a structure is provided in which the upper roller support 7 can be separated from the lower roller support 8. It is becoming. That is, as shown in FIG. 3, when the above-mentioned dogleg lever 25 is swung, the balance support structure 7A is displaced upward. This is two “dog” levers 25.
Since the distance between the support points in the column 24 and the length of the balance support structure 7A are the same, and the postures of both dogleg levers 25 are the same, a parallelogram link is formed and the balance The support structure 7A is displaced while maintaining a posture parallel to the lower roller support 8. However, since the parallelogram has an extremely short shape, even if one end of the dogleg lever 25A is rotated with the rod 33, the balance support structure 7A remains in a dogleg shape. Only the side of the square lever 25A rises and does not move parallel to the lower roller support 8. To assist this, a connecting rod 34 having the same length as the balance support structure 7A is further connected between the other end sides of both dogleg levers 25, and a rod 34 whose central portion is supported by the column 24 is connected between the other end sides of both dogleg levers 25. The lower side of the lever 25 forms a tall parallelogram link, ensuring reliable movement of the balance support structure 7A. The rotation of the dogleg lever 25, that is, the pushing and pulling of the connecting rod 34, is performed by a screw jack 35, which is a pushing and pulling mechanism that is swingably supported by the column 24. When the handle 36 is turned, the rod 33 moves forward and backward while expanding and contracting the dust cover 37 via a worm gear built into the gear box. Of course, if the screw jack 35 is restrained, the balance support structure 7
A can be fixed at a desired position.

The operation of the lance feeding device for a steelmaking electric furnace having such a configuration will be described below. Note that when the lance 3 is inserted toward the electric furnace 2, the lance posture is inclined, but in the drawings used for explanation, the lance is shown horizontally.

Long lance 3 connected by fittings
is held between the lance feeder and the lower roller 5
The upper roller 4 presses the lance 3 from above to prevent it from falling off. For example, oxygen is flowed into the lance 3 at a pressure of 8 kg/cm ² to raise the temperature of the molten steel and decarburize it. In this case, the lance 3 is fed at a speed of about 50 mm/min, for example, because the tip immersed in the molten steel is melted by heat.

The operation to make the lance feeder grip the lance 3 is as follows:
As shown in FIG. 1, turn the handle 36 of the screw jack 35 to push the rod 33. The connecting rod 34 is moved in the direction of arrow 38 by the rotation of the dogleg lever 25A, and the other dogleg lever 25B is also rotated. Both “dog” levers 25
The balance support structure 7A supported by the balance support structure 7A is lifted upward while maintaining a horizontal posture, and the bogie structure 7B suspended by the hanging tool 26 is also separated from the lower roller 5. The upper roller 4 supported by the bogie 23 is regulated by a drop stopper 28, so that one roller does not hang down. When a new lance 3 is placed on the lower roller 5 in this state, the screw jack 35 is reversely rotated to lower the balance support structure 7A, and the lance 3 is held between the upper roller 4 and the lower roller 5. Then, both the upper roller support body 7 and the lower roller support body 8 are tilted to a desired angle by a hydraulic cylinder (not shown) or the like.

The lower roller 5 is rotated by the drive of the motor 15,
The lance 3 is inserted into the molten steel from the slag discharge port. As the tip wears out, the lance 3 is fed in, and when the joint part 22 comes under the upper roller 4, the bogie 23
is inclined. FIG. 4 shows an example in which the joint portion 22 is located below the upper roller 4C, and the support point 23a of the bogie 23B rises only half of the upper roller 4C. Therefore, the inclination angle of the bogie structure 7B is also small, and the amount of compression of the pressure spring 27 is also small. As a result, the holding force does not increase significantly, and the holding force is distributed by the balance structure, so that the lance 3 is pressed evenly. Both the pressing by the upper roller 4 and the feeding by the lower roller 5 are performed in a state similar to the case shown in FIG. 1 in which the joint portion 22 is not mounted on the lower roller 5. Incidentally, as shown in FIG. 5, when the joint part 22 approaches one of the lower rollers 5C located in the center, the lower roller 5C has a supporting point that can be vertically displaced, so that the joint part 22
pushes down the lower roller 5C. The lance 3 is pressed by the upper roller 4 to maintain its horizontal position, and all the lower rollers 5 support the lance 3 to exert a predetermined feeding force. Both the pressing by the upper roller 4 and the feeding by the lower roller 5 are performed in a state similar to when the joint portion 22 is not mounted on the lower roller 5. Note that when the joint portion 22 comes over the lower roller 5A, which has a fixed support portion, the lance 3 appears to be lifted at that point. In that case, the entire lance 3 will be inclined, and each bogie 23 will also be inclined about the support point 23a along the inclination. At this time as well, the amount of contraction of the pressure spring 27 is suppressed, and the pressing force acting on each upper roller 4 does not become so large and is equal to all, as in the above explanation. Incidentally, in this example, one of the lower rollers 5 is resiliently supported, and when the joint portion 22 is reached, that roller descends, but in the present invention, the support point of the lower roller 5 is Lower roller 5
It can also be applied to cases where everything is immobile like A.

When the joint portion 22 passes through each roller and moves to such an extent that it becomes impossible to hold the lance as described above, it is replaced with a new lance.
Operate the screw jack 35 to raise the balance support structure 7A as described above, and
and the lower roller 5 are separated. Previous Lance 3
At the same time, a new lance is inserted from the rear in the feeding direction and placed on the lower roller 5. When the balance support structure 7A is lowered, the lance is clamped and sent into the molten steel through the slag outlet in the procedure described above.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the main parts of the lance feeding device for an electric furnace for steelmaking according to the present invention, Fig. 2 is a general schematic diagram of the lance feeding device, and Fig. 3 shows the state in which the upper roller support is separated from the lower roller support. Fig. 4 is a state diagram showing the inclined posture of the bogie when the joint part is directly under the upper roller; Fig. 5 is a state diagram when the joint part is on the resiliently supported lower roller; FIG. 6 is a schematic diagram of a lance feeding device in the prior art, and FIG. 7 is an explanatory diagram of the lance feeding operation. 1...Lance feeder, 2...Electric furnace, 3...
Lance, 4, 4A to 4D... Upper roller, 5, 5
A to 5D... Lower roller, 7... Upper roller support, 7A... Balance support structure, 7B... Bogie structure, 8... Lower roller support, 23, 23A,
23B...Bogie, 25, 25A, 25B...
"Dovetail" lever, 27...Pressure spring, 3
4...Connection rod, 35...Push/pull mechanism (screw jack).

Claims (1)

[Claims for Utility Model Registration] A lance is held between a plurality of rollers arranged on the upper and lower sides, and the lance is sent by driving the lower roller to tilt the upper roller support and the lower roller support. In the lance feeding device, the posture of the lance can be changed by moving the lance, wherein the upper roller support has a take-up support structure and a bogie structure, and the upper roller is supported in a bogie manner. A bogie structure equipped with two pairs of bogies is attached to a balance support structure so as to be able to change its posture, and a pressure spring is provided at the upper center of the balance support structure. The balance support structure is urged toward the lower roller support by a pressure spring, and both ends of the balance support structure are supported by one end of a dogleg lever whose center is supported by the lower roller support. A lance feeding device for an electric furnace for steelmaking, characterized in that the other end of the dogleg lever is connected by a connecting rod, and the connecting rod is connected to a push/pull mechanism.