JPH11158517A - Device for preventing clogging of mud gun and method for preventing clogging thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent the clogging of a nozzle while keeping the exchangeability of the nozzle part in a preventing device of clogging of a mud gun. SOLUTION: In the preventing device 10 of clogging of the mud gun 1 for closing an iron tapping hole 2a of a blast furnace, a coolant supplying system 7 for supplying the coolant composed of cooling water and the air and a mist atomizing nozzle 14 for atomizing as mist state to the nozzle part 1a in the outer peripheral surface of the mud gun, are combinedly equipped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device and a method for preventing clogging of a mud gun used for closing a tap hole of a blast furnace, and more specifically, to a mud gun inside a nozzle portion at a tip of a mud gun. And the work to remove the mud hardened by this seizure,
For example, the solidification of the mud at the time of low temperature in winter or the like can be all eliminated, thereby preventing the mud from being unable to be filled at the time of the next tapping hole closing operation. The present invention relates to a device and a blockage prevention method.

[0002]

2. Description of the Related Art In the operation of a blast furnace, after tapping is completed from a tap hole, the tap hole is closed by filling a tap hole closing material called a mud into the tap hole. A mud gun is used to fill the taphole with mud.

FIG. 9 is an explanatory view showing an outline of a tap hole closing operation using the mud gun 1. FIG. 9 (a) is a top view near the tap hole at the time of completion of tapping, and FIG. 9) is a top view near the tap hole at the time of mud filling, and FIG. 9 (c) is a side view near the tap hole at the time of mud filling shown in FIG. 9 (b).

In FIG. 1, a mud gun 1 which is a cylindrical body accommodating a mud therein stands by at a predetermined position until the start of taphole blockage as shown in FIG. 9 (a). When the tap hole is closed, as shown in FIGS. 9 (b) and 9 (c), the mud gun 1 is swiveled, turned, and tilted, and the nozzle 1a provided at the tip of the mud gun 1 is used for tapping. The mud is filled into the tap hole 2a by pushing the mud by pressing the tap hole 2a of the finished blast furnace 2.

After the mud is filled by the mud gun 1, the nozzle portion as shown in FIGS. 9 (b) and 9 (c) is used to sufficiently bake and solidify the mud inside the tap hole 2 a.
While keeping 1a pressed against tap hole 2a, it is held for about 30 minutes to 1 hour.

Since the hot metal 4 discharged from the tap hole 2a through the hot metal gutter 3 has a high temperature of about 1500 ° C., the nozzle portion 1a of the mud gun 1 has a high temperature molten metal discharged from the tap hole 2a. Or it is exposed to hot metal. Therefore, the mud that remains without being discharged inside the nozzle part 1a (usually 50-100 kg
(The degree remains), similar to the mud filled in the tap hole 2a, seizure, which is a phenomenon of being heated and solidified by receiving large radiant heat, occurs, thereby closing the inside of the nozzle portion 1a. If the nozzle section 1a of the mud gun 1 is closed, the next tap hole closing operation cannot be performed.
It is necessary to remove the solidified mud inside the tub, so-called boring.

However, the ambient temperature near the taphole 2a is 50
Since the temperature is 6060 ° C., the mud removal work in this atmosphere is a heavy labor work with a considerably large work load, and improvement is required in terms of the work environment.

Further, since the mud burned inside the nozzle portion 1a is not effectively utilized for closing the tap hole 2a, the use amount of the mud is increased wastefully. Therefore, from the viewpoint of reducing indirect material costs in the operation of the blast furnace, prevention of seizure is required.

Conventionally, with respect to the mud gun 1, there are known means for cooling water to the conical barrel portion 1b, and means for attaching a semi-cylindrical heat-insulating plate to the lower portion of the nozzle portion 1a for air cooling. However, these means are originally intended to protect the skin of the mud gun 1,
Since the cooling of the mud remaining inside is not considered, the cooling effect is insufficient and insufficient.

Therefore, at the time of blast furnace operation,
After closing the tap hole 2a using the mud gun 1, a worker in front of the furnace applies cooling water from a side surface of the mud gun 1 using a hose to prevent seizing of the mud. However, the atmosphere temperature on the hot metal gutter 3 side is high as described above, and the worker in front of the furnace cannot spray water continuously for one hour. In addition, since the mud gun 1 is cooled from one direction, uneven temperature distribution occurs inside the nozzle portion 1a, and it is difficult to completely eliminate the solidification of the mud. Therefore,
The effect of preventing the mud from being clogged in the nozzle 1a was small in spite of forcing the worker in front of the furnace to perform severe work.

On the other hand, in such a mud gun 1, since the outside air temperature decreases in cold weather such as winter, the mud accommodated in the mud gun 1 becomes highly viscous and hardens inside. For this reason, the mud gun 1 may be blocked, and the tap hole 2a may not be filled with mud at the time of the next tap hole closing operation.

For such low viscosity mud,
The nozzle 1a was heated using a C gas burner or the like. Figure
10 is an explanatory view showing a means using the C gas burner 5, FIG. 10 (a) is a side view, and FIG. 10 (b) is a front view. As shown in the figure, a C gas burner 5 connected to a pipe 6 for supplying C gas and air is disposed below the nozzle portion 1a, and the viscosity of the mud is reduced by burning the nozzle portion 1a from below. This caused the mud gun 1 to be blocked.

However, in this means, since the nozzle portion 1a is kept warm from one direction, the hardening of the mud cannot be completely prevented, and the mud cannot be filled in the next tap hole closing operation. Could not be resolved.

Various proposals have hitherto been made in order to prevent the mud gun from being clogged due to such solidification due to seizure or hardening in cold weather.

For example, in Japanese Patent Application Laid-Open No. 56-90906, a temperature adjusting mechanism comprising a flow path for allowing hot water and cooling water to flow freely is built in a nozzle portion of a mud gun.
An invention has been proposed in which, during standby before mud filling, hot water flows to prevent mud hardening in cold weather, and after mud filling, cool water flows to prevent mud burn-in.

In Japanese Utility Model Laid-Open No. 58-83441, an invention is proposed in which a cooling water distribution pipe is spirally wound around the outer peripheral surface of a nozzle portion of a mud gun to prevent mud seizure.

In Japanese Utility Model Laid-Open No. 59-76546, there is proposed an invention in which a cooling hollow chamber is provided in a nozzle portion and a cooling agent is injected into the cooling hollow chamber to prevent sticking of a mud. ing.

[0018]

However, since the nozzle portion of the mud gun is used in an environment which receives a violent splash of hot metal from a tap hole at the time of filling the mud, there is always a danger of erosion. Therefore, it is required that the nozzle portion which has been melted be easily replaced. However, in the inventions according to these proposals, the replacement of the nozzle portion is actually extremely difficult.

That is, the inventions proposed in JP-A-56-90906, JP-A-58-83441 and JP-A-59-76546 each have a built-in cooling mechanism in the nozzle portion. In addition, the structure of the nozzle portion becomes extremely complicated. Therefore, replacement of the melted nozzle portion also requires time and effort. In addition, since the manufacturing cost of the nozzle portion is increased, it is practically impossible to implement it.

It is an object of the present invention to provide a mud gun blockage prevention device and a blockage prevention method which can be implemented simply and practically.
An object of the present invention is to provide a mud gun blockage prevention device and a blockage prevention method that can reliably prevent nozzle blockage due to solidification and hardening of the mud inside while maintaining exchangeability of the nozzle portion.

[0021]

As described above, the means for providing the cooling water flow path inside the nozzle portion 1a to prevent the sticking of the mud reduces the exchangeability of the nozzle portion 1a which is damaged by use. At the same time, the manufacturing cost of the nozzle portion 1a increases.

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, as shown in FIG. 1 for explaining the outline of the present invention, they are usually arranged around a casting bed where a hot metal gutter is installed. A cooling medium supply system 7 that connects a pipe 7b for industrial water (hereinafter, referred to as “work water” in the present specification) and a compressed air pipe (hereinafter, referred to as a “pneumatic pipe” in the present specification) 7a. And a spraying unit 8 for spraying the supply medium supplied by the cooling medium supply system 7 in a mist form. The cooling medium supply system 7 and the injection unit 8 are used to cut the outer peripheral surface of the nozzle unit 1a of the mud gun 1. It has been found that by spraying water in the form of a mist, the nozzle portion 1a can be reliably cooled and solidification due to mud seizure can be prevented without substantially changing the conventional nozzle portion structure.

In addition, the present inventors, upon this cooling,
Since the water sprayed on the outer peripheral surface of the nozzle portion 1a of the mud gun 1 is in the form of a mist, it evaporates immediately after spraying and does not adversely affect equipment in a hot state such as a hot metal gutter below. did. In addition, the present inventors have found effective conditions for the shape and the spray pattern of the injection unit 8 for performing the mist spray of the working water.

Further, the present inventors have proposed a cooling medium supply system 7.
In the middle of the process, a heating medium supply system is provided in a switchable manner, for example, by providing an electromagnetic valve and automatically opening and closing the electromagnetic valve, and providing a heating medium to the outer peripheral surface of the nozzle portion 1a of the mud gun 1. It has been found that by changing the spraying method, the hardening of the mud caused by lowering the viscosity in cold weather or the like can be prevented.

The present inventors have further studied based on these findings, and as a result, completed the present invention.

Here, the gist of the present invention is a device for preventing a mud gun from closing a taphole of a blast furnace, comprising: a cooling medium supply system for supplying a cooling medium comprising cooling water and air; An apparatus for preventing clogging of a mud gun, comprising a combination of an ejecting unit for spraying a medium in a mist shape at least to a tip portion of an outer peripheral surface of the mud gun.

In the mud gun blockage prevention apparatus according to the present invention, a heating medium supply system for supplying a heating medium comprising C gas and air or steam is provided so as to be switchable with a cooling medium supply system. It is desirable to inject the warm medium from the injecting section in order to prevent both the seizure and the blocking of the mud gun caused by the low viscosity in cold weather.

In the mud gun blockage preventing device according to the present invention, the injection unit is provided outside the mud gun outer peripheral surface.
At least a plurality of mist spray nozzles connected in an arc shape is desirable for uniformly cooling the mud gun while preventing melting of the spraying portion.

In the above-described device for preventing clogging of a mud gun according to the present invention, the mist spray nozzle has a hole diameter of 1 to 3 mm, and the distance between adjacent mist spray nozzles is 20 to 30 mm. It is desirable to ensure that the mudgun is cooled without adversely affecting the equipment in the condition.

Further, from another viewpoint, the present invention provides a method for spraying a mist-like cooling medium consisting of cooling water and air onto all or a part of the outer peripheral surface at least at the distal end of the mud gun. A method for preventing a mud from being clogged, wherein the method prevents solidification of the mud.

In the above-described method for preventing the clogging of the mud gun according to the present invention, the flow rate of the cooling medium sprayed in the form of mist is set to 0.1.
To ensure that the mud gun is cooled without adversely affecting hot equipment such as hot metal gutters when the cooling medium is 4 to 0.6 m ³ / H or the diameter of the cooling medium is 1 mm or less. Both are desirable.

In the present invention, “clogging of the mud gun” means “solidification due to seizure” or hardening at a low temperature.
This means that the mud is closed to such an extent that it cannot be extruded from the inside of the tube tip such as the nozzle.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) Hereinafter, an embodiment of a mud gun blockage prevention device and a blockage prevention method according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is an explanatory view showing an embodiment of the blockage preventing device 10 of the present embodiment, and FIG. 3 is a diagram illustrating a situation when the blockage preventing device 10 sprays water.

As shown in FIG. 2, the blockage prevention device 10 of the present embodiment comprises a cooling medium supply system 7 for mixing and supplying working water and air, and a supply medium supplied by the cooling medium supply system 7. And a spray unit 8 for spraying at least the nozzle portion 1a of the outer peripheral surface of the mud gun 1 in a mist form.

In the present embodiment, the cooling medium supply system 7 is connected at one end to a compressor (not shown), and is connected to a compressed air pipe 7a extending toward the vicinity of the mud gun 1 and to a point in the compressed air pipe 7a. A water pipe 7b, a bendable flexible hose 9 connected to the other end of the compressed air pipe 7a, and a flexible hose 9 attached to the nozzle portion 1a by appropriate means while branching into two on the outer peripheral surface of the mud gun 1. 9 and a branch pipe 11 connected to the pipe 9.

Attachment of the branch pipe 11 to the mud gun 1
Appropriate means may be used and is not limited to a specific means.
In the present embodiment, the compressed air pipe 7a is fixedly supported by annular support bands 13 mounted on the outer peripheral surface of the mud gun 1. Therefore, there is no need to change the internal structure of the mud gun 1, and the nozzle portion 1a can be easily replaced as in the conventional case. In addition, on the outer peripheral surface of the main body of the mud gun 1,
A mud insertion hole 1c is provided.

Each of the compressed air pipe 7a and the working water pipe 7b is provided with solenoid valves 12a and 12b which are opened and closed by remote control. By appropriately controlling the opening and closing operations of the solenoid valves 12a and 12b, the branch pipe 11 is opened. One or both of compressed air and working water can be supplied. Thereby, the cooling medium can be sprayed in a mist shape from a mist spray nozzle 14 described later toward the outer peripheral surface of the nozzle 1b by remote control.

In this embodiment, the flexible hose 7 is interposed between the compressed air pipe 7a and the branch pipe 11,
This is for absorbing the turning operation and the tilting operation of the mud gun 1.

In the present embodiment, mist spray nozzles 14 as spraying parts are respectively installed at the two end portions of the branch pipe 11. The mist spray nozzle 14 is a nozzle provided with an injection hole having a diameter of about 2 mm, and sprays a cooling medium, which is a mixture of working water and air, supplied to the branch pipe 11 in a mist shape.

In the present embodiment, the mixture of working water and air is used as the cooling medium because the ambient temperature alone is 50 to 60 ° C. and the temperature of the nozzle part 1a is 300 to 500 ° C. This is because the cooling capacity is insufficient and solidification of the mud cannot be prevented. On the other hand, if only the working water is used, it is necessary to jet a considerable amount of water in order to uniformly cool the entire outer peripheral surface of the nozzle 1a, and the water drops down into a hot metal gutter installed below the mud gun 1 to cool the hot metal. At the same time, it adversely affects the refractory constituting the hot metal gutter. In addition, cooling unevenness occurs between a portion where water is directly injected and a portion where water is not directly injected.

The mist diameter is adjusted to be about 1 mm or less, and the mist amount is adjusted to be 0.4 to 0.6 m ³ / H. Further, it is desirable to change the amount of mist according to the temperature of the nozzle portion 1a. Thus, by appropriately controlling the mist diameter and the mist amount, the working water sprayed on the outer peripheral surface of the nozzle portion 1a of the mud gun 1 evaporates immediately and does not drip downward.

The blockage prevention device 10 of the present embodiment is configured as described above. Next, the operation of the blockage prevention device 10 will be described. 4 (a) to 4 (g) are explanatory diagrams showing the procedure for closing the tap hole 2a of the blast furnace with the use of the mud gun 1 including the blockage prevention device 10 of the present embodiment over time.

In FIG. 4 (a), the mud gun 1 into which the mud has been charged through the mud charging hole 1c moves the nozzle portion 1a until the discharge of the hot metal 4 from the tap hole 2a of the blast furnace 2 is completed.
It is waiting at a predetermined position toward the opposite side of 2a.

In FIG. 4 (b), when the discharge of the hot metal 4 is completed, the mud gun 1 turns around the fulcrum 15 to invert and turns the nozzle 1a toward the tap hole 2a. FIG. 4 (c) shows the mud gun 1 in the state shown in FIG. 4 (b).
FIG.

In FIG. 4D, the mud gun 1 performs a tilting operation to press the nozzle portion 1a against the tap hole 2a.

In FIG. 4 (e), when the mud housed in the mud gun 1 is pushed out by the plunger 1d, filling of the tap hole 2a with the mud is started.
In (f), the mud filling operation is completed inside the tap hole 2a. When the mud is filled into the tap hole 2a, it is desirable that the nozzle portion 1a be covered with a smoke collecting hood 16 as shown in FIG.

In FIG. 4 (g), after filling of the mud is completed,
The electromagnetic valves 12a and 12b in FIG. 2 are opened, and a cooling medium composed of working water and air is sprayed from the injection nozzle 14 into a mist toward the nozzle portion 1a. Until the mud filled in the tap hole 2a is completely sintered (about one hour after the filling is completed, set one hour with a timer when performing)
The mud gun 1 is left in the state shown in FIG. At this time, the cooling medium composed of working water and air is sprayed in the form of a mist, thereby preventing the mud remaining inside the nozzle 1a of the mud gun 1 from burning.

After confirming that the mud filled in the tap hole 2a was completely sintered, the mud gun 1 was moved to the position shown in FIG.
Returning to the position shown in (a), the injection nozzle 14
The spraying of the cooling medium from is also stopped.

As described above, according to the present embodiment, the nozzle 1a of the mud gun 1 can be cooled effectively and without waste by spraying the cooling medium composed of working water and air in a mist. Seizure of the mud remaining in the first nozzle portion 1a is prevented. This can eliminate the mud removal operation (wattle cutting) performed at the timing between the next tapping. Therefore, seizure of residual mud in the nozzle portion 1a of the mud gun 1 performing the closing operation on the tap hole 2a can be prevented easily and inexpensively.

That is, according to the present embodiment, the cooling of the nozzle portion 1a of the mud gun 1 can be performed only by modifying the existing compressed air pipe 7a and the working water pipe 7b to extend around the mud gun 1. . Therefore, there is no need to modify the internal structure of the mud gun 1 or the like at all, and the exchangeability of the nozzle portion 1a equivalent to the conventional one can be ensured.

According to the present embodiment, the mud gun 1
By reusing the mud that has been discarded because it remains in the nozzle portion 1a and is burned, the amount of mud discarded can be significantly reduced. Therefore, the amount of mud used can be reduced.

Further, according to the present embodiment, since the cooling medium composed of working water and air is sprayed in the form of a mist, the conditions of the mist diameter and the amount of the mist are appropriately set.
The sprayed cooling medium can be prevented from dripping downward from the nozzle portion 1a of the mud gun 1 and adversely affecting refractories such as hot metal gutters.

(Second Embodiment) Next, a description will be given of a second embodiment of a mud gun blockage prevention apparatus and method according to the present invention. The following description of each embodiment will be made only for portions different from the first embodiment, and common portions will be denoted by the same reference numerals in the drawings, and redundant description will be omitted as appropriate.

FIG. 5 shows a blockage prevention device 10-1 according to this embodiment.
FIG. 5 (a) is a side view, and FIG. 5 (b) is a front view. FIG.
(a) is a front view partially showing the mist spray nozzle 14-1 in the present embodiment, and FIG. 6 (b) is a side view partially showing the mist spray nozzle 14-1.

This embodiment differs from the first embodiment in the shape of the mist spray nozzle 14-1. That is,
In the present embodiment, the mist spray nozzle 14-1 is almost covered except for the lower part of the mud gun 1 and the distance d is 20 to 30.
It was constituted by an arcuate hollow pipe in which a large number of injection holes 17 having a diameter of 2 mm and a radius r of about 2 mm were connected.

By arranging the mist spray nozzle 14-1 so that the lower part thereof is partially missing, the mist spray nozzle 14-1 is prevented from being damaged by the radiant heat from the hot metal gutter located below.

As shown in FIG. 6B, the cooling medium is sprayed from the mist spray nozzle 14-1 as a mist having a diameter of less than 1 mm so that the spread angle θ is 45 degrees or more. Thus, the nozzle portion 1a of the mud gun 1 can be uniformly cooled regardless of the portion, and the cooling of the nozzle portion 1a and the prevention of burn-in of the mud can be reliably achieved.

The volume ratio between the working water sprayed from the mist spray nozzle 14-1 and the compressed air is desirably about 1:10, and the supply amount of each is 0.4 to 0.6 m ³ / H, 4 to 6 m. ³ / H
Desirably.

In this embodiment, a thermometer 18 is installed near the nozzle 1a, and the mist amount is controlled in accordance with the actually measured temperature of the nozzle 1a. That is, the primary target temperature and the final target temperature are set for the temperature of the nozzle portion 1a, respectively, and the mist amount is increased until the temperature of the nozzle portion 1a decreases from the cooling start temperature to the primary target temperature. The mist amount is gradually reduced when the temperature is reduced from the primary target temperature to the final target temperature. Thereby, the working water sprayed on the outer peripheral surface of the nozzle portion 1a of the mud gun 1 evaporates immediately and does not drip downward.

Therefore, excessive cooling is prevented.

(Third Embodiment) FIG. 7 is an explanatory view showing a situation in which the blockage prevention device 10-2 of the present embodiment is applied to a mud gun 1. FIG. 7 (a) is a side view, and FIG. ) Is a front view.

In the present embodiment, a steam pipe 7c and a C gas pipe 7d are connected to the cooling medium supply system 7, and the compressed air pipe 7a, the steam pipe 7c, and the C gas pipe 7d of the cooling medium supply system 7
A heating medium supply system 19 is provided so as to be switchable with respect to the cooling medium supply system 7, and unlike the first and second embodiments, has a structure capable of not only cooling the nozzle portion 1a but also heating it.

The compressed air pipe 7a, the working water pipe 7b, the steam pipe
Manual valves 20a to 20d are provided in the 7c and C gas pipes 7d.

That is, when cooling the nozzle portion 1a, the manual valves 20a and 20b are opened and the manual valves 20c and 20d are opened.
Is closed, the cooling medium composed of working water and compressed air is sprayed in a mist form from the mist spray nozzle 14-1 as in the second embodiment. On the other hand, when heating the nozzle portion 1a, the manual valves 20a, 20c and 20d are opened and the manual valves are opened.
By closing 20b, the cooling medium supply system 7 is switched to the heating medium supply system 19, and the heating medium is injected from the mist spray nozzle 14-1 around the nozzle portion 1a to uniformly heat the nozzle portion 1a. I do. This makes it possible to reliably prevent the mud from hardening due to the temperature drop inside the nozzle portion 1a.

In this embodiment, the steam pipe 7c and the C gas pipe
For independent connection to 7d, for example, to obtain a large heat retaining effect, use a C gas pipe 7d to inject a mixture of C gas and compressed air, and to obtain a small heat retaining effect, use a steam pipe. Steam can be injected using 7c. Thereby, the degree of heating of the nozzle portion 1a can be freely adjusted.

[0067]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A mud gun blockage prevention apparatus and a blockage prevention method according to the present invention will be described in detail with reference to embodiments.

The blockage prevention device 10 according to the second embodiment shown in FIG.
Using a mud gun equipped with -1, a tapping hole of a blast furnace where tapping was completed was performed. At the same time as the filling of the tap hole with the mud was completed, the cooling medium composed of working water and compressed air was sprayed as mist to the nozzle portion 1a by the blockage prevention device 10-1. The amount of mist was controlled according to the pattern shown in the graph of FIG. The mist amount is controlled by the solenoid valve 12a,
It was controlled automatically by the controller that controls 12b.

When 60 minutes have passed since the start of cooling, that is, when the outer surface temperature of the nozzle portion 1a dropped by about 450 ° C. to about 50 ° C., the spraying of the cooling medium was stopped, and the mud gun was returned to the original position. Returned.

As described above, in this embodiment, the mist amount is set to 0.4 m ³ / H while the nozzle temperature is between the cooling start temperature (about 500 ° C.) and the primary target temperature (100 ° C.). Target temperature (100
(° C) to the final target temperature (50 ° C).
Linearly reduced to 1m ³ / H. As a result, no dripping of the sprayed working water occurred.

Then, the burning state of the mud inside the mud gun was confirmed. As a result, no mud was solidified, and the mud was ready for use in the next tap hole closing operation.

As described above, according to the present embodiment, it is possible to reduce both the amount of mud used and the so-called rattling.

[0073]

As described above in detail, the apparatus for preventing blockage of a mud gun and the method for preventing blockage of the mud gun according to the present invention can maintain the exchangeability of the nozzle portion while solidifying the mud inside and further blocking the nozzle due to hardening. Can be reliably prevented, thereby reducing the amount of mud used and the work load.

The significance of the present invention having such effects is extremely remarkable.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an outline of a mud gun blockage prevention device according to the present invention.

FIG. 2 is an explanatory diagram showing an embodiment of a blockage prevention device according to the first embodiment.

FIG. 3 is an explanatory diagram illustrating a situation at the time of spraying working water by the blockage prevention device of the first embodiment.

FIGS. 4 (a) to 4 (g) are explanatory diagrams showing a procedure for blocking a tap hole of a blast furnace with a mud gun provided with the blockage preventing device of the first embodiment over time.

FIGS. 5A and 5B are explanatory views showing a situation in which the blockage prevention device according to the second embodiment is applied to a mud gun. FIG. 5A is a side view and FIG. 5B is a front view.

FIG. 6 (a) is a front view partially showing a mist spray nozzle according to a second embodiment, and FIG. 6 (b) is a side view partially showing a mist spray nozzle.

FIGS. 7A and 7B are explanatory views showing a situation in which the blockage prevention device of the third embodiment is applied to a mud gun. FIG. 7A is a side view, and FIG. 7B is a front view.

FIG. 8 is a graph showing a mist amount control pattern in the embodiment.

FIG. 9 is an explanatory view showing an outline of a tap hole closing operation using a mud gun. FIG. 9 (a) is a top view near the tap hole when tapping is completed, and FIG. 9 (b) is a mud filling. FIG. 9 (c) is a side view of the vicinity of the tap hole at the time of filling the mud shown in FIG. 9 (b).

FIGS. 10A and 10B are explanatory views showing a conventional means for blocking a mud gun caused by lowering the viscosity of the mud. FIG. 10A is a side view, and FIG. 10B is a front view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mud gun 1a Nozzle part 2a Tap hole 7 Cooling medium supply system 10 Blockage prevention device 14 Mist spray nozzle

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroyasu Hayakawa 3rd Ojimitsu, Kashima City, Ibaraki Prefecture Sumitomo Metal Industries, Ltd. Kashima Works, Ltd. (72) Inventor Shoji Osumi 3rd Ojimitsu Kashima City, Ibaraki Prefecture Sumitomo Metal Industries Co., Ltd. Kashima Works, Ltd. (72) Inventor Go Tsuyoshi Sasaki, 3rd Ojimitsu, Kashima City, Ibaraki Prefecture Sumitomo Metal Industries, Ltd.Kashima Works, Ltd. (72) Inventor Uzumi 3rd, 3rd Ojimitsu, Kashima City, Ibaraki Prefecture Sumitomo Metal Industries, Ltd. In-house (72) Inventor Masahiro Teramura No. 3, Oaza Hikari, Kashima-shi, Ibaraki Prefecture Sumitomo Metal Industries, Ltd.

Claims (2)

[Claims] 1. An apparatus for preventing a mud gun from closing a taphole of a blast furnace, comprising: a cooling medium supply system for supplying a cooling medium composed of cooling water and air; A mud gun blockage prevention device, comprising a combination with an injection unit that sprays at least to a tip portion in a mist shape. 2. A mist-like spray of a cooling medium composed of cooling water and air onto all or a part of an outer peripheral surface of at least a tip portion of a mud gun that closes a tap hole of a blast furnace, thereby forming a mist inside the mud gun. A method for preventing clogging of a mud gun, which prevents solidification of the mud.