JPH0224508Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a tundish with a molten steel heating device, and in particular utilizes heat absorption due to evaporation of water remaining in the water-cooling jacket for the heating coil when repairing the tundish. This invention relates to a tundish with a molten steel heating device that has a cooling water storage tank that can maintain the jacket at a temperature below its heat-resistant temperature, and is widely used in the field of continuous steel casting.

[Conventional technology]

In continuous casting of steel (hereinafter referred to as continuous casting), molten steel produced in a converter, etc. is stored in a ladle and transferred to a continuous casting tandy, where it is passed through an immersion nozzle, etc. that reaches the mold from the bottom of the tundish. Injected into mold. As described above, the temperature of molten steel inevitably decreases as it is transferred from the ladle to the tundish and then to the mold. However, since the casting temperature is extremely important in continuous casting, a tundish equipped with a molten steel heating device is used to heat the molten steel in the tundish if there is a risk that the molten steel in the tundish may drop below the planned casting temperature.

Normally, molten steel heating equipment is shown in Figures 4 and 5.
A channel type low frequency induction heating device as shown in Figures A and B is used. That is, it consists of a heating chamber 4 which is integrated with the tundish main body 2 on the side of the tundish main body 2, and the heating chamber 4 communicates with the inside of the tundish main body 2 and has a channel part 8 which accommodates the molten steel 6, an iron core 10 and a heating chamber 4. As shown in FIG. 5A, the channel portion 8 is formed into an arc shape with a refractory material 14, and an iron core 10 is placed in the center of the arc and surrounds the channel portion 8 through the refractory material 14. A heating coil 12 is wound around one side of an iron core 10 located above and below the center of the channel section 8, and a water cooling jacket 16 is attached to the outer periphery of the heating coil 12 via an insulating material. is provided. Therefore, when low frequency power is applied to the coil 12, the molten steel 6 in the channel portion 8 becomes a secondary coil of the coil 12 and is heated by induction.

The heating coil 12 is usually made of copper, but when it is energized it generates heat and may even rise in temperature and melt, so it usually has a hollow structure and is designed to cool itself by passing water inside. .

On the other hand, since the outer periphery of the coil is in contact with the molten steel 6 through the refractory material 14, if the refractory material 14 is damaged by being corroded by the molten steel 6, there is a risk that the coil 12 and the iron core 10 will be damaged by melting. A cooling device is provided in which a water cooling jacket 16 is provided and cooling water 18 is circulated. As shown in FIG. 2, the water cooling jacket 16 is a cylindrical body provided on the outer periphery of the coil 12, and is provided with cuts 20 to prevent the formation of a closed circuit of induced current. During continuous casting, as shown in FIG. 4, is supplied from a tundish truck 22. However, the lifespan of the refractory material 14 of the tundish 2 is limited to the casting of molten steel for several ladles, and the refractory material 14 is transported to a repair shop by crane or transport truck for lining repair.

However, since the refractory material 14 in the heating device 4 is still at a high temperature even after the casting is finished, it is necessary to run cooling water for a while after the casting to protect the coil 12. I need to run water through it. For this reason, conventionally, when the tundish was moved by a crane or the like, a very long water supply hose was connected to the water supply pipe 26 of the water cooling jacket 16 of the heating device 4 to continue water supply. As a result, the range of movement of the tundish with a heating device for repair is limited, and workability is extremely poor due to the need to pull a long hose.

[Problem that the invention attempts to solve]

An object of the present invention is to provide a tundish with a molten steel heating device having a simple structure and solving the problems of the prior art described above.

[Means for solving problems]

The gist of the present invention is as follows.
That is, a channel part fixed to the side of the tundish body, an iron core surrounding the channel part in an annular manner via a fireproof material, a heating coil surrounding the inner columnar part of the iron core, and the heating coil. In a tundish with a molten steel heating device, the tundish includes a water cooling jacket surrounded by an insulating material,
a cooling water storage tank provided at the top of the molten steel heating device at a higher position than the water cooling jacket; and a water passage having one end at the bottom of the tank and the other end removably connected to the water passage pipe of the water cooling jacket. A tundish with a molten steel heating device characterized in that it has a steam exhaust duct having one end detachably connected to the drain pipe of the water cooling jacket and the other end opening to the upper part of the tank.

As shown in FIG. 4, the tundish 2 with a molten steel heating device is used for continuous casting, and since there is molten steel 6 in the channel 8, the refractory material 1 around the heating device 4 is
4 becomes quite high in temperature, it is necessary to flow a considerable amount of cooling water into the jacket 16 in order to protect the coil 12.

However, since there is no molten steel 6 inside after use, strong cooling by the water cooling jacket 16 is not necessary.

The present inventors developed a water-cooled jacket 1 before and after using continuous casting.
The results of measuring the change in surface temperature of No. 6 are shown in FIG. As is clear from Fig. 3, during continuous casting, the amount of cooling water in the water cooling jacket 16 is 32/3.
The surface temperature of the jacket 16 was approximately 100°C at the time of cooling, but after use, the surface temperature of the jacket decreased to 60°C with the same amount of cooling water.

Therefore, at point P, 30 minutes after the use of the tundish 2 was stopped for continuous casting, the amount of cooling water in the jacket 16 was reduced to 10/min, and as a result, the surface temperature of the jacket 16 became constant at about 100°C. In other words, in order to maintain the same surface temperature of 100℃ as during continuous casting, the amount of cooling water after use must be 10/min.
was found to be sufficient.

Furthermore, when the Q point was reached 40 minutes after the end of continuous casting and the cooling water to the water cooling jacket 16 was stopped, the jacket 16
The surface temperature of the jacket gradually rose until it reached point R, where the water remaining in the jacket passageway began to boil. The jacket surface temperature at this time was 200°C. Then, when the point R was reached and cooling water was supplied in an amount equal to the amount of water that evaporated in the passageway of the jacket 16, the surface temperature gradually decreased and reached a nearly constant temperature of about 150° C. 60 minutes after the end of continuous casting.

That is, it has been found that after continuous casting is completed, the jacket 16 can be maintained at a temperature below the heat-resistant temperature by replenishing only the evaporated amount of water remaining in the passageway of the jacket 16. The present invention was completed based on the above experimental results.

An embodiment of the present invention will be described with reference to FIGS. 1 and 2. In the present invention, first, a cooling water storage tank 24 is provided above the molten steel heating device 4 at a position higher than the water cooling jacket 16. A water passage duct 28 is provided from the bottom of the tank 24 to the water passage pipe 26 of the jacket 16, a joint 30 thereof is made easily attachable and detachable, and a water flow regulating valve 32 is provided in the middle. Next, the drain pipe 34 of the water cooling jacket 16 and the removable joint 3
A steam exhaust duct 38 having one end at 6 and an open end at the top of the tank 24 was provided. Note that an exhaust hole 40 is provided in the upper part of the tank 24. A schematic diagram of the pipe connection is shown in Fig. 2.
Based on the above experimental results, the capacity of the tank 24 is determined by the amount of water that evaporates in the water cooling jacket 16 after continuous casting is completed, and is determined by the capacity of the heating device of the tundish 2. Since the amount of evaporation of water in the heating device was approximately 4 per hour, the tank capacity was set to 5.

[Effect]

When continuous casting by the tundish, which receives molten steel 6 from several ladles and is scheduled to be repaired, is completed, the connection of the cooling water with the trolley 22 is disconnected, and the energizing path to the heating coil is disconnected, and the heating device is disconnected. Prepare to transport the attached container to the repair shop. Thereafter, the valve 32 is opened to switch to cooling from the cooling water storage tank 24, and the supply of cooling water in the tank 24 to the water cooling jacket 16 through the water duct 28 is started. The amount of cooling water supplied is approximately 4/Hr for a 1000Kw heating device. During this period, if the cooling water in the water cooling jacket 16 evaporates due to a lack of cooling water, the volume will increase rapidly, and the generated steam will be discharged from the drain pipe 34 of the jacket 16 through the removable joint 36 and into the upper part of the tank 24. It is safely discharged through the steam exhaust duct 38, cooled and returned to the cooling water in the tank 24, or discharged as steam through the steam exhaust hole 40.

[Effects of the invention] The tundish with a molten steel heating device that is transported to a repair shop for lining repair after continuous casting according to the present invention has the following features: A cooling water storage tank 24 is provided at the top of the heating device to cool the jacket 16 through the water pipe 26 of the water-cooled jacket, and to safely discharge the steam generated inside the jacket 16.
Steam is safely transferred to the tank 24 through the discharge pipe 34 of 6.
Since a steam exhaust duct 38 was provided to release the steam inside, the following effects could be achieved.

(b) When transporting the tandy tank to a repair shop after continuous casting, the water supply from the trolley 22 can be immediately cut off, the energizing cable can be disconnected, and the water supply can be switched to the tank 24. Since there is no longer a need for a long water supply hose, the workability of transfer can be significantly improved.

(b) The present invention is a tank 2 installed at the top of the molten steel heating device.
In addition to 4, only the extremely simple equipment of a removable water flow duct 28 and a steam exhaust duct 38 connected to the water supply and drainage end of the jacket 16 are added, so the equipment cost and operating cost are extremely low, and the operation is easy. It's extremely easy.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing a tundish with a molten steel heating device according to the present invention, and Fig. 2 shows a water cooling jacket 16 and a cooling water tank 2 in the present invention.
Fig. 3 is a schematic perspective view showing the state of connection of piping with No. 4, Fig. 3 is a diagram showing the transition of the relationship between the water supply amount and surface temperature of the water cooling jacket of the tundish after the completion of continuous casting in the basic experiment of the present invention, and Fig. 4 5 is a sectional view showing a conventional tundish with a molten steel heating device mounted on a tundish truck, and FIGS. 5A and 5B show a molten steel heating device attached to the conventional tundish, where A is a plan sectional view and B is a longitudinal sectional view. 2... Tandate body, 4... Molten steel heating device, 6... Molten steel, 8... Channel portion, 10...
Iron core, 12...Heating coil, 14...Refractory material,
16... Water cooling jacket, 22... Tundish truck, 24... Cooling water tank, 26... Jacket water pipe, 28... Water passage duct, 34... Jacket drain pipe, 38... Steam discharge duct.

Claims (1)

[Scope of utility model registration request] A channel portion fixedly installed on the side of the tundish main body, an iron core surrounding the channel portion in an annular manner via a fireproof material, a heating coil surrounding the inner columnar portion of the iron core, and an insulating material surrounding the heating coil. A tundish with a molten steel heating device, comprising: a cooling water storage tank provided at an upper part of the molten steel heating device at a higher position than the water cooling jacket; a water flow duct having one end removably connected to a water flow pipe of the water cooling jacket; and a steam exhaust duct having one end removably connected to a drain pipe of the water cooling jacket and the other end opening at the top of the tank. A tundish with a molten steel heating device characterized by having the following.