JPH0663707B2 - Molten metal container tapping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a container, such as a converter, a mixed pig furnace, an electric furnace, a ladle, a tundish, for containing high-temperature molten metal, from the bottom of these containers. The present invention relates to a tapping device for tapping molten metal.

(Prior Art) The above-mentioned various molten metal containers receive molten metal (or melt the metal in the container), hold it for a certain period of time for refining or storing, and then discharge the molten metal toward the subsequent process. Used. Therefore, in addition to the function of receiving and holding the molten metal, these containers are required to have the function of discharging the molten metal. Generally, since the molten metal handled by these containers is high temperature, ordinary metal valves cannot be used, so in order to discharge molten metal from the container,
Conventionally, one of the following methods has been mainly used.

(A) Method of tilting the container: In a converter, a mixed pig iron furnace, an electric furnace, etc., the container containing the molten metal is tilted so that the molten metal is tapped through an opening at the upper end or a tap hole provided on the side of the container.

(B) Method for mechanically opening and closing the tap hole at the bottom of the container: For ladle, tundish, etc., a tap hole is provided at the bottom of the container, and a mechanical stopper such as a refractory nozzle plug or sliding gate Is provided, the molten metal is received by closing it, and the molten metal is discharged by opening it.

Regarding a rotary furnace, a tapping device having a structure in which a tapped hole having a special shape is provided at the bottom of the furnace and the molten metal in the furnace is tapped or the tapping is stopped by changing the rotation angle and inclination angle of the furnace. (JP-A-60-234915) has been proposed.

(Problems to be Solved by the Invention) However, each of the methods (a) and (b) has the following problems.

(A) In case of tilting: -Since it takes time for tilting, the operation time cycle becomes long.

・ While the molten metal is contained, it is located above the molten metal, and the molten metal is discharged while coming into contact with the low temperature part of the refractory that is not in contact with the molten metal. Go down.

・ According to the above, when the container is tilted, the slag (molten slag) floating on the molten metal comes into contact with and erodes a wide range of refractory materials, expanding the erosion range of the refractory material and increasing the life of the refractory material. Becomes shorter.

・ When tapping, the slag is easily mixed in the molten metal and the amount of slag discharged together with the molten metal is large, so it is difficult to remove slag in the subsequent process, and the quality of the metal may deteriorate. .

・ Depending on the type of container, auxiliary equipment such as a tilting device and a crane for tilting is required exclusively for tapping hot water.

(B) In case of mechanical opening / closing of tap hole: ・ Nozzle plug or sliding gate directly blocks outflow of molten metal when closing tap hole, so thermal and mechanical erosion action by molten metal It will be damaged severely, and its service life will be extremely short. For this reason, the nozzle plugs and the like are frequently replaced, which requires time for parts replacement work and increases operating costs.

(Object) The present invention has been made in view of the above points, and after holding molten metal in a container, hot water can be discharged from the bottom of the container without tilting the container, and the service life of each component is long. Accordingly, the present invention aims to provide a molten metal container tapping device that can reduce operating costs.

(Means for Solving Problems) The gist of the present invention for achieving the above-mentioned object is to open a tap hole at the bottom of a molten metal container such as a converter or a mixed pig iron furnace, An opening / closing lid for closing the lower end opening is provided, and a cooling mechanism for cooling the upper end opening of the tap hole with a cooling medium is provided.

(Operation) According to the molten metal container tapping device of the present invention, when tapping the molten metal contained in the container, by opening the opening / closing lid of the tap hole lower end opening opened at the bottom of the container, When tapping is started, and most of the molten metal in the container is tapped and the slag remains, the upper end opening of the tap hole is cooled by a cooling medium to solidify the molten metal or slag and the tap hole top end. The hot water supply is stopped by closing the hot water supply port. In this state, the lower end opening of the hot water supply port is closed by the opening / closing lid, so that the hot water supply port is completely closed.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a converter (oxygen-blown converter) equipped with a tapping device according to a first embodiment of the present invention. In the figure, 1 is a converter as a container, 1a is a furnace shell, 2 is a furnace refractory composed of consumable bricks 2a and permanent bricks 2b.
Is a hot water discharge device according to the present invention. Hot water supply device 11 of the present embodiment
Has the following structure. That is, a tap hole 12 is formed in the center of the bottom of the converter 1, and a cooling mechanism 13 for blowing a cooling medium around the tap hole 12 is provided with tuyere 13a, tuyere pipe 13b, and piping.
It is formed by 13c. The tuyere 13a is composed of a plurality of nozzles formed of, for example, a heat-resistant metal material, and these nozzles are on the inner surface side of the converter 1 and the upper end opening of the tap hole 12 is formed.
There is an opening around 12a. Further, around the tuyere pipe 13b, refractory 14a for protecting the inner surface and refractory 14b and 14c for filling the gap between the furnace body refractory 2 are constructed, and these are supported by the metal 15, It is fixed to the furnace body iron shell 1a through a connecting metal fitting 16. Furthermore, the lower end opening of the tap hole 12
A nozzle stopper 17 as an opening / closing lid for mechanically closing the opening 12b is provided near 12b so as to be freely opened and closed. The nozzle stopper 17 has a refractory nozzle plug 17c fixed to the tip of an arm 17b, the base end of the arm 17b is pivotally attached to the converter 1 via a pivot shaft 17a, and is closed by a drive device 18. When rotated in the direction, the nozzle plug 17c is configured to fit into the bottom opening 12b of the tap hole.

The tapping operation is performed as follows by using the tapping device 11 configured as above.

FIG. 2 is a sectional view showing a state where molten steel refined in the converter 1 is being tapped. In the figure, 3 is molten steel, 4 is slag, 21 is a known oxygen upper blowing lance used by being inserted into the furnace through the furnace port 1b for refining, and 22 is a post-process after receiving the molten steel 3 discharged from the molten metal. It is a ladle to carry to.
In the illustrated state, since the nozzle stopper 17 is opened, the molten steel 3 flows from the tap hole 12 at the bottom of the converter 1 into the converter 1
It is poured into the ladle 22 located just below.

Continuing the illustrated state, the molten steel 3 in the converter 1 is replaced by the ladle 22.
Immediately before the hot water is discharged to the slag 4 and the slag 4 is discharged, the hot water discharge work is stopped by the following work steps (1) to (4).

(1) It is detected that the slag 4 has descended to the vicinity of the upper end opening 12a of the tap hole 12. For this purpose, the molten steel 3 and the slag 4 may be visually identified, but may be automatically detected using various known sensors.

(2) The cooling medium 19 is caused to flow in through the pipe 13c and blown out through the tuyere pipe 13b through the tuyere 13a into the converter 1. As the cooling medium 19 used here, for example, it has a large cooling capacity because it decomposes at a high temperature and involves a large amount of heat absorption at that time.
Hydrocarbon-based gas is most suitable.

(3) The cooling medium 19 causes the slag 4 (or molten steel 3) near the tuyere 13a to drop in temperature and solidify, and as shown in FIG. 3, from the tuyere 13a to the upper end opening 12a of the tap hole 12 A solidified portion 4a is formed, and by this, the upper end opening of the tap hole 12
The 12a part is closed, and the outflow of the molten steel 3 and the slag 4 is stopped.

(4) With the outflow of the molten steel 3 and the slag 4 from the tap hole 12 completely stopped, the nozzle stopper 17 is rotated about 180 ° by the drive device 18, and the nozzle stopper 17 is inserted into the tap hole bottom end opening 12b.
C is fitted and the tap hole 12 is closed. Also, the cooling medium 19
Stop blowing into the furnace. At this time, the inflow of the molten steel 3 into the tap hole 12 is already stopped by closing the upper end opening 12a of the tap hole 12 by the cooling / solidifying action of the slag 4 (or the molten steel 3) by the cooling medium 19. Since the nozzle plug 17c itself does not directly block the outflow of the molten steel 3 or the slag 4, the damage to the nozzle plug 17c is extremely small.

After tapping the molten steel 3 in the converter 1 in this way, the molten steel 3
The ladle 22 into which is injected is carried out, the converter 1 is inverted, and the slag 4 in the converter 1 is discharged from the furnace port 1b. then,
The converter 1 is returned to the original upright state, and the next refining hot metal 3'is received in the converter 1. The manner in which the molten pig iron 3 ′ housed in the converter 1 is smelted and discharged is as follows.

(A) Immediately before receiving the hot metal 3 ', the inert gas 20 is introduced through the pipe 13c and blown out through the tuyere pipe 13b into the converter 1 through the tuyere 13a. This is due to the melting of the tuyere 13a and the tuyere 1
The purpose is to prevent the molten metal 3 '(or molten steel 3) from flowing into the inside 3a, and further to promote refining by stirring the molten iron 3'in the converter 1 with an inert gas. Argon gas is usually used as the inert gas 20, but nitrogen gas may be used depending on the type of steel to be refined, or a small amount of the above-mentioned hydrocarbon gas for cooling may be blown out. It is desirable that the blowing of this kind of gas is continued from when the converter 1 receives the hot metal 3 ', until the molten steel 3 that has been smelted is completely discharged.

(A) After the hot metal 3'is received in the converter 1, it is refined by a well-known oxygen top blowing lance 21. During this time, the following phenomenon occurs near the tap hole 12: That is, the tap hole upper end opening 12 formed in the step of tapping work (3).
The solidified portion 4a near a is melted by the heat retained by the hot metal 3'when the hot metal 3'is received in the converter 1, and becomes a molten state. Therefore, the upper end opening 12a is opened and The hot metal 3'flows in and reaches the nozzle plug 17c at the lower end of the hot metal 3 '. However, the hot metal 3 ′ near the bottom opening 12b of the tap hole
Is surrounded by refractory material, and the nozzle plug 17c
Since it is also cooled by, the temperature immediately drops and solidifies to form a solidified layer 3a as shown in FIG. Therefore, the nozzle plug 17c covered with the solidified layer 3a is prevented from coming into contact with the molten pig iron 3 '(or molten steel 3) in a molten state (high temperature), and the damage to the nozzle plug 17c is minimized.

(C) When refining is completed in the converter 1, the nozzle stopper 17
Is rotated about 180 ° in the opening direction by the drive device 18 to open the bottom end opening 12b of the tap hole and start tapping. On this occasion,
The solidified layer 3a formed in the above step (a) is easily extruded by the pressure of the molten steel 3 in the converter 1, and then the molten steel 3
Is tapped from the tap hole 12 to the ladle 22.

In addition, when a large amount of molten steel 3 remains in the converter 1, if the cooling medium 19 is blown out from the tuyere 13a to close the tap hole upper end opening 12a and stop the molten steel 3 discharge. The molten steel 3 without the slag 4 can be tapped into the ladle 22, or the molten steel 3 can be split into a plurality of ladle 22 and tapped.

By the way, if the molten steel 3 flowing into the tap hole 12 solidifies and grows and the molten steel 3 cannot be tapped even if the nozzle plug 17c is opened, for example, the tuyere 13a or the oxygen top blowing Oxygen gas is blown out from the lance 21 and the heat of reaction with the molten steel 3 causes the upper end opening of the tap hole.
The temperature of the molten steel 3 near 12a is raised to melt a part of the solidified layer 3a, and the pressure of the molten steel 3 causes the solidified layer 3a in the tap hole 12 to melt.
From the side of the lower end opening 12b of the tap hole 12, through the solidification layer 3a in the tap hole 12 with a piercer device by a mechanical means such as a drill, or a piercer device at the tip of the lance 21. Deploy it, lower the lance 21, and use this piercer device to make a tap hole.
The molten steel 3 can be tapped by penetrating the solidified layer 3a in 12 and opening the tapping hole 12.

Further, as described above, when the converter 1 is turned over to discharge the slag remaining in the converter 1, the nozzle stopper 17 is opened and sand 25 or the like is pre-filled in the tap hole 12, and as shown in FIG. If the nozzle stopper 17 is closed as shown, the solidified layer
Since 3a is not formed deep inside the tap hole 12, the molten steel 3 can be tapped smoothly when the nozzle stopper 17 is opened.

Next, FIG. 6 is a cross-sectional view showing another embodiment of the hot water discharge device of the present invention. Instead of the nozzle stopper 17 of the above embodiment,
A sliding gate 31 is slidably arranged at the lower end opening 12b of the tap hole 12, and the gate 31 is opened and closed by a driving device 32. Also in this case, the refractory 31a that constitutes the majority of the sliding gate 31 is directly connected to the molten steel 3
Since it does not block the flow of, it can withstand long-term use. In addition, in the drawings, constituent members common to the above-described embodiment are denoted by the same reference numerals.

Further, instead of providing the cooling mechanism 13 for blowing the cooling medium 19 in the converter 1 as in the above-described two embodiments, the above-mentioned oxygen-blowing lance 21 is lowered to allow the cooling medium 19 to flow from the lance 21. It is also possible to block the tap hole 12 and stop the tapping by spraying the molten steel 3 or the slag 4 near the upper end opening 12a of the tap hole to solidify. Incidentally, the tapping device of the present invention is not limited to the oxygen top blowing converter described above, it can also be applied to a bottom blowing converter of the type in which oxygen is blown from the bottom of the furnace body, further, a mixed pig furnace, electric It can be similarly applied to a molten metal container such as a furnace, a tundish or various ladle.

(Effects of the Invention) Since the present invention is configured as described above, it has the following effects.

(A) By tilting the container, such as a converter, a hot metal furnace, an electric furnace, etc., as compared with the conventional tapping method in which molten metal is tapped from above, the container is tilted for tapping. Since it is not necessary, it does not take time to tilt the container, and the operation time cycle is shortened.

When the molten metal contained in the molten metal is tapped, the temperature of the molten metal does not decrease because the molten metal does not come into contact with the low temperature part of the furnace refractory material in the upper part of the container.

-Since the range in which the slag floating on the molten metal comes into contact with the refractory does not expand, the erosion range of the refractory due to the slag is narrow and the life of the furnace refractory is extended.

-When tapping the molten metal, the molten metal is barely mixed with the slag, so that the slag removing work in the subsequent process is reduced and the quality of the metal is not deteriorated.

-Since the tilting device and the crane for tilting were exclusively equipped for tapping hot water, for example, in a mixed pig furnace and some ladles, these devices are not required, so the structure is simplified.

Since the tap hole of the present invention is formed at the central position of the bottom of the container, the container shape is configured to be axisymmetric, and therefore various stresses generated in the shell (iron skin) of the container during use of the container are prevented. There is no concentrated area and the life of the container is extended.

(B) Compared with a conventional tapping device, such as a ladle or tundish, which is provided with a mechanical stopper such as a nozzle plug or a sliding gate in the tapping hole at the bottom of the container, and only opens and closes the molten metal. When the hot water is stopped, the refractory that composes most of the opening / closing lid such as the nozzle plug and sliding date does not directly block the outflow of molten metal, so the damage to the opening / closing lid itself is greatly reduced. , The service life is very long. For this reason, the frequency of exchanging the opening / closing lid or the refractory material thereof is reduced, and the operating cost is also reduced.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention, FIG. 1 is a sectional view of the tap hole in an open state, FIG. 2 is an overall schematic sectional view showing the tap hole, and FIG. 3 is a sectional view of the tap hole. FIG. 4 is a sectional view showing a state in which the upper end opening is closed, FIG. 4 is a sectional view showing a state in which the tap hole is completely closed by an opening / closing lid, and FIG. 6 and 6 are sectional views showing another embodiment of the present invention. 1 ... Converter, 3 ... Molten steel, 4 ... Slag, 11 ... Hot water supply device, 12 ... Hot water outlet, 12a ... Top opening, 12b ... Bottom opening, 13 ... Cooling mechanism, 17 ... Nozzle Stopper, 19 ……
Cooling medium, 21 …… Lance, 22 …… Ladle, 31 …… Sliding gate.

Claims (1)

[Claims] 1. A molten metal container such as a converter or a hot metal furnace is provided with a tap hole at the bottom, and an opening / closing lid is provided to close the bottom opening of the tap hole, and the top opening of the tap hole is cooled by a cooling medium. A molten metal container hot water discharge device comprising a cooling mechanism for cooling.