JPS6356284B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for opening a tap hole in a blast furnace, particularly to a method for opening a tap hole using oxygen gas.

(Prior Art) As is well known, in blast furnaces used for producing pig iron, a method has been adopted for many years to tap the molten pig iron by using a drill to drill through the tap hole, which is blocked by a filled mud. However, as blast furnaces have become larger and the number of times of tapping has increased, people have begun to consider ways to shorten the time required to drill the holes, and various hole-opening methods have been developed.

For example, Japanese Patent Application Laid-Open No. 53-54103 discloses a means for opening a hole by irradiating a laser on a plug hole plug, and Japanese Patent Application Laid-open No. 58-39711 discloses a method for opening a hole by irradiating a taphole with a plug. Immediately after the taphole is closed, with only the vicinity of the inner end surface of the mud being fired, the mud gun is removed, a round steel bar is inserted into the mud using the taphole opening machine, and the taphole opening machine is retracted. A method is shown in which only a round steel bar is left in a mat, and after the mat has been fired and hardened, the round steel bar is pulled out and a tap hole is opened when necessary.

Furthermore, in Japanese Patent Publication No. 58-189311, in a method of opening the tap hole by irradiating a laser to the plugged mat of the blast furnace taphole, when closing the taphole after the completion of tapping of the blast furnace, the blockage refractory A material that is easily vaporized by combustion is filled in advance in the material, and the next time the iron is tapped, the blocked taphole is irradiated with a laser and auxiliary gas for combustion of the easily vaporized material is simultaneously injected. , discloses means for smoothly opening the blocked tap hole by combusting and vaporizing the easily vaporized substance in the tap hole.

In addition, the present inventors previously devised a method for opening a taphole as shown in the schematic diagram of the configuration in FIG.

The key point of this method is to use an oxygen lance delivery device 5 which holds a straight pipe-shaped oxygen lance 4 facing the tap hole 2 of the blast furnace 1 so as to be able to deliver it freely. The oxygen lance gripping roller 7, which is thus rotatably driven, is engaged with the oxygen lance delivery device 5 by means of a rod rotatably suspended from the pivot arm 8.
The swing arm 8 is mounted on a bearing device 10 fixed to a frame 9 and is rotatably driven by a rotation motor, such as an air motor 11, so that the oxygen lance 4 is positioned so as to directly face the tap hole 2.

An oxygen gas supply main pipe (not shown), such as a flexible hose, is connected to the oxygen lance 4.

Therefore, this method does not remove the steel rod 3 that remains in the tap hole 2 or that has been buried in advance.
Then, oxygen gas is blown onto the plugging material 3a from the oxygen lance 4 to open the steel rod 3 and the plugging material 3a while co-combusting and melting the oxygen lance 4, and details thereof are shown in a perspective view in FIG. This will be explained according to the diagram.

Components having the same symbols as those in FIG. 7 are the same members, so a description thereof will be omitted.

In the figure, the hot metal trough 12 is located below the taphole 2 and is connected to a slag separator (not shown) through the cast bed. 13 is a heat insulating cover that covers the upper part of the hot metal trough 12, and also has the function of preventing the hot metal from scattering.

Now, as mentioned above, the hole drilling work is performed using the oxygen lance 4 from the oxygen lance delivery device 5, but due to the positional relationship with the molten pig iron trough 12 as shown in the figure, the hole drilling is completed and the tapping is started. Thereafter, it is necessary to quickly evacuate, and the swing arm 8 is operated to move to the standby position 8f as shown by the chain line in the figure.

At that time, the oxygen lance feeding device 5 also moves 5f.
However, in order to reduce the movement range of the long oxygen lance 4 and make it easier to handle, the link mechanism 1 is
4 is attached to the rotating arm to move the oxygen lance delivery device 5 in parallel.

(Problems to be Solved by the Invention) As a result of research into a more efficient and safer blast furnace taphole opening method, the present inventors found that there are still many issues remaining with the conventional method. I learned.

In other words, the invention described in JP-A No. 53-54103 (hereinafter referred to as Invention A) requires a considerably high equipment cost and requires a tap hole with a predetermined hole diameter and a straight axis for operation. Technical problems remain in drilling, and in the invention described in JP-A No. 58-39711 (hereinafter referred to as the B invention), when pulling out the round steel bar left in the closed mud, the round steel bar is If this happens, it becomes necessary to manually blow oxygen gas onto the remaining round steel bar using an oxygen gas blowpipe to melt and remove it, which actually increases the drilling time. The problem is that it tends to get long.

Furthermore, the invention described in Japanese Patent Application Laid-open No. 58-189311 (hereinafter referred to as the C invention) has the same problems as the A invention that the equipment cost is quite high and maintenance is not easy. Technical issues remain, such as the hole probe is easily damaged due to high heat and requires great skill to operate.

Furthermore, in the taphole opening method explained in FIGS. 7 and 8, since a 20 to 30 m straight oxygen lance is used, the oxygen lance 4 is
In addition to requiring a lot of manpower to set the oxygen lance 4 or to manually hold the rear end of the oxygen lance 4, it also takes a lot of time to connect, transport, and store the oxygen lance 4, so drilling work is difficult. Although it is efficient, it is desired to save labor and improve work safety.

As explained above, technical problems remain with Inventions A, B, and C, and improvements are considered necessary.

By the way, since the method of opening a blast furnace taphole is carried out in a high-temperature, dusty working environment, which is usually narrow and has poor footing, a simpler and safer method is desirable. However, none of the known methods to date are satisfactory.

(Means for Solving the Problems) As a result of reconsidering all of the above-mentioned well-known methods and researching improvements, the inventors of the present invention have devised a method for straightening a colorized steel pipe that has been previously wound into a coil shape and applying it to the taphole. We developed a method for opening a blast furnace taphole by blowing oxygen gas in contact with the hole, and succeeded in solving the problems mentioned above.

(Function) The specific method of the present invention will be explained below along with its function with reference to the drawings.

The inventors of the present invention opened a tap hole that had been blocked by a filling mat using various well-known methods. The method of blowing and igniting gas and burning and melting the filling mat or the filling mat and the steel rod together with the oxygen lance while opening the holes has a shorter opening time and is much more efficient than other known methods. Confirmed that it is excellent.

The inventors of the present invention conducted various research in search of a suitable material for oxygen lances, since the consumption of oxygen lances is enormous, and even if work efficiency can be improved, there is an economical problem. Ivy.

For example, steel pipes for general use (JISG3421), steel pipes for high temperature and high pressure use (JISG3423), and steel pipes for chemical industry (JISG3426).
and other non-ferrous metals, such as aluminum pipes, copper pipes,
I have tested brass tubes and titanium tubes, but they all wear out quickly, or break, break, or bend, making them uneconomical for their purpose and unable to provide practical effects. .

In addition, an oxygen lance for opening a taphole must have physical properties that allow it to maintain straightness and plunge into the taphole at a predetermined angle while burning and melting. It was also confirmed that it was not possible to obtain a tap hole with an inclination angle and hole diameter of .

Therefore, when a colorized steel tube, which is a type of heat-resistant tube, was tested as an oxygen lance, it was found to be very effective.

This colorized steel pipe is a steel pipe that is made by embedding the steel pipe in a penetrating agent and heating it to 900 to 1000°C in a sealed state to form an iron-aluminum alloy layer with a thickness of, for example, 0.3 to 0.8 mm on the surface of the steel pipe. As for mild steel,
Chrome steel, stainless steel, etc. can be used.

Next, we tried the hole-opening method shown in Figure 7 using the colorized steel pipe as an oxygen lance, and as a result, the work efficiency was improved as expected. However, there were still problems with transportation, setting up, and the need for a lot of manpower to move the oxygen lance, which also left safety issues unresolved.

Therefore, the inventors of the present invention developed a flange structure for colorized steel pipe 18, which was thought to be unsuitable for use as an oxygen lance because it would crack or break if subjected to processing such as bending with a large curvature. 1
5a, 15b and the winding drum 16, which is a bobbin type winding drum 17. In the figure, 18a is the start of winding the calorized steel pipe 18,
That is, the starting end was made to protrude outward through a through hole (not shown) provided in the winding drum 16 to facilitate connection with oxygen supply equipment. 18b indicates the end of winding of the colorized steel pipe 18, that is, the terminal end.

Next, as shown in the schematic diagram of FIG.
As a result of trying to straighten the pipe by inserting it into the straightening device 21 (hereinafter simply referred to as straightening machine) consisting of 20b, it was confirmed that failures such as cracks and crushing, which were initially feared, did not occur.

Furthermore, a coiled colorized steel tube made by colorizing a steel tube previously formed into a coiled shape was fixed on the winding drum 17, but there were no cracks or crushing as had been feared, and it was found to be usable. This was confirmed.

In the present invention, both of the above are referred to as a colorized steel pipe wound into a coil.

Next, as shown in the schematic explanatory diagram of FIG. 4, drilling work was carried out using the blast furnace taphole opening device 22.

In the figure, the calorized steel pipe 18 is wound around a winding drum 17 rotatably supported by an oxygen lance feeding device 23, straightened and straightened by a straightening machine 21, and then placed at a tap port 2 of a blast furnace 1. It is rolled out in the direction of. 3 indicates a steel rod that was cut and remained in the taphole during the extraction operation, or was buried in advance, and since both of them exist in the taphole in almost the same form, the present invention In this case, both are considered to be the same steel rod, and in that sense, they are defined as "pre-buried steel rods."

Next, reference numeral 24 denotes a flexible hose for oxygen supply, which is connected to an oxygen supply device 25, and the flexible hose 24 is connected to a colorized steel pipe 18 wound around a winding drum 17 via a swivel joint (not shown). Connected to the starting end.

The swing arm 26 rotatably suspends the oxygen lance delivery device 23 via a suspension rod 27, and is further mounted on a bearing device 29 fixed to a frame 28 such as a pillar, beam, or deck around the blast furnace. A driving motor such as an air motor 30
It is rotatably driven by. In the present invention, this is referred to as the swing arm being rotatably supported by the structure.Next, 31 is a clutch mechanism with a return device, which rotates the swing arm 26 mainly using an air motor 30 in the drilling operation position. It has the function of separating from the mechanism and allowing the swing arm 26 to rotate freely.

Reference numeral 32 denotes a pressing force applying device having a tension wire 33 that is locked at one end to the rotating arm 26 and wound around a rotary drum (not shown) at the other end so as to be freely wound and unwound.

Now, using the taphole opening device 22, the straightening machine 21 is operated by a control device (not shown) to straighten the colorized steel pipe 18, and while it comes into contact with the taphole, oxygen gas is ignited and opened. The drilling work was extremely efficient, and the work time, which conventionally required 30 to 80 minutes, was reduced to 5 to 15 minutes.

Next, the method of using the oxygen lance delivery device 23 will be described in more detail, including its structure.

As mentioned above, the colorized steel pipe is used as an oxygen lance in the present invention, and in that sense, both terms will be used interchangeably hereinafter.

FIG. 5 shows the details of the structure of the oxygen lance feeding device 23 and the straightening machine 21.
4 is a horizontal guide roll 35 from the winding drum 17
A feeding force is applied by a feeding roller 37 whose rotational speed is variable and which is driven by an air motor 36 for driving in a forward and reverse direction. 38a~
38d is a group of straightening rollers, and as described above, the oxygen lance 34 is straightened while passing through the roller groups 38a to 38d, and is fed out from the guide 39 toward the tap hole. Reference numeral 40 is a shaft that supports the entire oxygen lance feeding device 23, and is pivotally supported by a suspension rod 41. The frame 42 has a lifting mechanism, and the shaft 4
It is equipped with a function to raise and lower the oxygen lance feeding device 23 relative to the oxygen lance 34, thus adjusting the position of the oxygen lance 34 and making the opening operation easier, but it is not possible to provide such a mechanism as appropriate. Be free.

(Example) FIG. 6 is a schematic perspective view of a blast furnace taphole opening device according to an example for explaining the method of the present invention in detail. 2
A swing arm 44 is rotatably supported by a bearing device 43 fixed to a bearing device 8 .

A lifting device 46 and an oxygen lance feeding device 47 are rotatably suspended from the tip of the swing arm 44 via a hanging rod 45, and an oxygen lance 48 is wound around the oxygen lance feeding device 47. The winding drum 49 and straightening machine 50 are mounted on the tower, and the oxygen lance 48 is straightened as described above and is fed out from the guide 51 in the direction of the tap hole 2.

Reference numeral 52 denotes an air motor for driving the swing arm 44, which is equipped with a clutch mechanism 53 and is separated from the swing of the swing arm 44 in the opening position.

Reference numeral 54 denotes a tension wire to which a constant tension is applied from a torque motor 56 via a drum 55, and one end of which is latched to the swing arm 44.

Therefore, the swing arm 44 is rotated in the two directions of the tap hole with a constant force by the tension wire 54 after the clutch mechanism is activated by a limit switch or the like (not shown) in the same way as explained in FIG. Therefore, no excessive force is applied to the oxygen lance 48 that may cause it to bend or break, regardless of whether the combustion melting is successful or not.

Furthermore, if the straightening/feeding speed of the straightening machine 50 is controlled manually or automatically, the stability of the hole-drilling operation can be further improved.

Although an example in which a swing arm is used as a means for carrying out the method of the present invention has been described above, the method is not limited to these means, and it is preferable to use a rail traveling type bogie 57 as shown in the schematic explanatory diagram of FIG. methods can be adopted.

In the figure, a rail 59 is fixed on a work floor 58.
A rail running type bogie 57 (hereinafter simply referred to as a bogie), which moves forward and backward via running wheels 60a and 60b, faces two directions of the tap hole by a running prime mover (not shown), such as an air motor. It moves me like that.

A lifter 61 for adjusting the elevation angle is provided on the cart 57, and a winding drum 62 and a straightening machine 63 are mounted on the lifter 61. It is always fed out at a predetermined angle in two directions of the tap hole. Driving motors such as the winding drum 62 and the straightening machine 63 are omitted from illustration.

In addition, a device for adjusting the feed-out speed of the straightening machine 63 and for pressing the trolley 57 in two directions of the tap hole with a constant torque after the driving motor is separated from the driving mechanism at the drilling work position, such as the above-mentioned torque motor and tension wire. Drilling work can be carried out more smoothly by adding tools such as the use of a machine and the use of a weight.

In addition, oxygen was supplied to the oxygen lance 64 from an oxygen gas supply main pipe (not shown) using a flexible hose and a fluid rotary joint.
No problems occurred.

(Effects of the invention) The method of the present invention is much easier to work with than the conventional method, and improves the efficiency of blast furnace taphole opening work in a narrow, high-temperature, and dusty atmosphere by 2 to 5 times the conventional method. In addition, it is possible to significantly improve work safety, and due to the labor-saving effect, labor costs can be significantly reduced to 1/2 to 1/4 of that of conventional methods.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of an embodiment of the method of the present invention, FIG. 2 is a schematic front view of a winding drum around which a colorized steel pipe is wound, FIG. 3 is a diagram illustrating straightening procedures for a colorized steel pipe, The figure is a schematic explanatory diagram of an embodiment method according to the present invention, FIG. 5 is a functional explanatory diagram of a part of the apparatus for carrying out the method of the present invention, and FIG. 6 is a diagram showing the openings used in the embodiment of the present invention. FIG. 7 is a schematic perspective view of the device, FIG. 7 is an explanatory diagram of the procedure for hole-drilling using a straight-tube oxygen lance, and FIG. 8 is a schematic perspective view of a blast furnace taphole-opening device also using a straight-tube oxygen lance. 1...Blast furnace, 2...Tapping port, 3...Steel rod, 3a...Closing material, 4, 34, 48, 64...Oxygen lance, 5, 2
3, 47... Oxygen lance feeding device, 6... Oxygen lance gripping roller, 7, 27, 41, 45... Hanging rod, 8, 26, 44... Swivel arm, 9, 28... Frame, 10, 29, 43... Bearing device, 11,3
0, 36, 52...Air motor, 12...Hot metal gutter,
13... Heat insulation cover, 14... Link mechanism, 15a,
15b...flange, 16...winding drum, 17, 49, 6
2... Winding drum, 18... Colorized steel pipe, 18a
...Calorized steel pipe starting end, 18b...Carolized steel pipe terminal end, 19a to 19e...Correcting roller, 20a, 2
0b... pinch roller, 21,50,63... straightening machine, 22... taphole opening device, 24... flexible hose, 25... oxygen supply device, 31, 53... clutch mechanism, 32... pressing force applying device, 33 ,54...
Pull wire, 35...Horizontal guide roll, 37
... Feeding roller, 38a to 38d... Straightening roller group, 39, 51... Guide guide, 40... Shaft, 42
... Frame, 46... Lifting device, 55... Drum, 5
6...torque motor, 57...rail running trolley, 58
...Working floor, 59...Rail, 60a, 60b...Traveling wheels, 61...Elevation angle adjustment lifter.

Claims (1)

[Claims] 1. A method for opening a blast furnace taphole, which is characterized in that a calorized steel pipe that has been previously wound into a coil is brought into contact with the taphole while being straightened, and the hole is opened by blowing oxygen gas.