JP2004114056A - Molten metal holding vessel and method for cooling outer wall thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simultaneously restrain rising of temperatures of both on not only a driving device, but also, an iron shell in a molten metal holding vessel having a sliding nozzle and this driving device. <P>SOLUTION: In the molten metal holding vessel having the sliding nozzle and this driving device, a heat-insulating plate between a range faced to the driving device in the iron shell as the outer wall of the molten metal holding vessel and the driving device, is disposed so as to make a gap between the heat-insulating plate and the iron shell, and this vessel is constituted so as to make cooling gas flow into this gap. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention prevents overheating of the sliding nozzle driving device in the molten metal container having the sliding nozzle and its driving device, and also prevents overheating deformation of the outer skin of the molten metal container in a range opposed to the driving device. The present invention relates to a molten metal container and an outer wall cooling method for preventing the molten metal container at the same time.
[0002]
[Prior art]
In a molten metal container having a sliding nozzle typified by a ladle and a driving device therefor, a driving device (an electric cylinder for opening and closing the sliding nozzle, an electric motor, etc.) is installed outside a steel shell which is an outer wall of the container. However, they must of course be kept below their respective service temperatures. In the state where the molten metal is stored inside, even if there is a refractory lining, the outer shell of the molten metal container becomes hot, and the radiant heat from the steel shell causes the drive unit installed near the steel The temperature also increases, and may occur when the temperature exceeds the service temperature.
[0003]
Regarding a ladle held in a vacuum refining apparatus and subjected to refining at a high temperature for a long time, a water cooling panel is provided on the outer surface of the vacuum refining vessel as proposed by the present applicant in Patent Document 1, and a driving device is provided. Can be cooled indirectly. However, in such indirect cooling, only the surface of the drive unit opposite to the steel shell is cooled, and the surface of the drive unit facing the steel shell and the surface of the steel shell facing the drive unit are cooled. There was an inconvenience that it was not done.
[0004]
Therefore, conventionally, a simple method of installing a heat insulating plate between the ladle and the driving device has been used to cut off the radiant heat from the iron skin of the ladle. In this method, it is possible to block the radiant heat from the steel shell to the drive device, but on the other hand, the heat dissipation from the heat insulating plate and the steel shell is reduced, so that the steel shell temperature rises above the service temperature, There was a problem that the steel skin was deformed.
[0005]
[Patent Document 1]
JP-A-6-65461 [0006]
[Problems to be solved by the invention]
In the molten metal container having the sliding nozzle and its driving device, it is necessary to simultaneously suppress not only the driving device but also an increase in the temperature of the iron sheath of the molten metal container facing the driving device. However, the conventional method has not provided an effective solution for suppressing the temperature rise of both.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention relates to a molten metal container having a sliding nozzle and a driving device therefor, wherein an outer shell of the molten metal container, an area facing the driving device and the driving device are provided. A method for cooling an outer wall of a molten metal container (1st invention), wherein a heat insulating plate is provided between the heat insulating plate and the steel shell so as to form a gap between the heat insulating plate and the steel shell, and a cooling gas is caused to flow through the gap. ).
[0008]
Further, the present invention relates to a molten metal container having a sliding nozzle and a driving device therefor, wherein an insulating plate is provided between the driving device and a steel shell which is an outer wall of the molten metal container and which is opposed to the driving device. A molten metal storage container (second invention), wherein a gas ejection device for supplying a cooling gas is provided in the gap so as to form a gap between the heat insulating plate and the steel shell. Is also proposed.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
The molten metal storage container targeted by the present invention is a container for storing and transporting a high-temperature molten metal inside, and has a sliding nozzle for controlling the discharge of the molten metal at the bottom thereof. A driving device (for example, an electric cylinder, a hydraulic cylinder, an electric motor, etc.) for driving is provided along the outer skin of the steel shell. In the present invention, the molten metal container is exemplified by a ladle as a representative as described above, but is not limited thereto.
[0010]
FIG. 1 shows a configuration example of the present invention. That is, FIG. 1 is a front view schematically showing a molten metal container 1 and a driving device storage box 2 for storing a driving device for a sliding nozzle. FIG. 2 shows an example of the arrangement of the driving device 3, the heat insulating plate 4, and the header 6 for supplying the cooling gas 5 in the driving device storage box 2 shown in FIG. 2A is a side view, and FIG. 2B is a front view. In FIG. 2, the display of the entire outer shell of the drive device storage box 2 is omitted. In FIG. 2, reference numeral 8 denotes a high-temperature molten metal held in the container 1, and reference numeral 9 denotes a lining refractory.
[0011]
In the present invention, the heat insulating plate 4 is provided between the iron shell 7 which is the outer wall of the molten metal container 1 and the driving device 3 of the sliding nozzle (not shown). As a result, the radiant heat from the steel shell 7 to the driving device 3 can be cut off, and the temperature rise of the driving device 3 can be suppressed even when the molten metal is stored in the molten metal storage container 1.
In addition, by flowing the cooling gas 5 into the gap between the heat insulating plate 4 and the steel shell 7, heat removal from the steel shell 7 is promoted, and the temperature rise of the steel shell 7 is prevented. If the temperature rise of the steel shell 7 can be prevented, the radiant heat transmitted from the steel shell 7 to the heat insulating plate 4 can also be reduced, which is advantageous for preventing the temperature rise of the driving device 3. As described above, according to the present invention, it is possible to suppress a rise in the temperature of the driving device 3 and the iron shell 7.
[0012]
Here, the heat insulating plate 4 installed between the outer wall of the molten metal container 1 (that is, the iron shell 7) and the driving device 3 of the sliding nozzle is installed in a range where the driving device 3 receives radiant heat. It is installed so that a gap of a certain distance is formed between the skin and the skin 7. Then, from the end of the heat insulating plate 4 covering the steel shell 7, nitrogen or air or the like is flowed as cooling gas 5 through the cooling gas jetting device such as the header 6 into the gap between the steel shell 7 and the heat insulating plate 4. Cooling. As shown in FIG. 2, the cooling gas 5 can be efficiently cooled by flowing upward from the lower end of the heat insulating plate 4. The reason is that the flow of the cooling gas 5 is not hindered by the natural convection of the air that is heated on the surface of the steel shell 7 and rises.
[0013]
In the present invention, the method of supplying the cooling gas 5 includes the following methods (1) and (2), and it does not matter which method is used.
(1) As long as the molten metal container 1 stores molten metal therein, the cooling gas 5 is always supplied as described above.
(2) The cooling gas 5 flows only when the molten metal container 1 is at a specific position.
[0014]
However, in the case of the above (1), while the effect of increasing the cooling efficiency is exhibited, it is necessary to provide a cooling gas supply facility in the molten metal storage container 1 main body or in all processes passing through the molten metal storage container 1. Yes, a large capital investment and a large amount of cooling gas are required, resulting in an increase in cost. Therefore, (1) or (2) may be appropriately selected and adopted in consideration of the required cooling capacity, equipment restrictions, equipment maintenance load, allowable cost range, and the like.
[0015]
The present inventors receive molten metal from a molten metal production facility such as a refining furnace or a melting furnace into a molten metal container 1, and perform secondary refining such as vacuum degassing as necessary, and perform casting equipment such as continuous casting. In the position where the molten metal is allowed to flow out of the molten metal container 1 into the tundish or the mold, the temperature of the surface of the iron shell 7 of the molten metal container 1 and the surface of the driving device 3 facing the iron shell 7 are continuously set. The change in the surface temperature of the iron shell 7 and the surface temperature of the driving device 3 over time after the molten metal was stored was investigated. At the time of this investigation, the temperature transition was investigated in a state in which the cooling gas 5 was not always supplied. The result is shown in FIG.
[0016]
As is apparent from FIG. 3, the temperatures of the iron shell 7 of the molten metal container 1 and the driving device 3 of the sliding nozzle particularly reach high temperatures because a long time has elapsed since the molten metal 8 was stored, and It was found that the molten metal was present immediately below the metal container 1 and the molten metal container 1 was present on a casting facility receiving a large amount of radiant heat therefrom.
[0017]
Also, considering that the casting equipment is often provided with a cooling gas supply device for peripheral devices of the sliding nozzle, in the case of the above-described process, the iron of the molten metal storage container 1 is cast by the casting equipment. It is most efficient to flow the cooling gas 5 into the gap between the skin 7 and the heat insulating plate 4.
[0018]
【Example】
The present invention was applied to a molten steel pot having a capacity of 280 ton / charge as the molten metal storage container 1, and its effect was confirmed. The molten steel 1550-1650 ° C. after refining in the converter is subjected to 280 tons of steel per charge to the molten steel pot 1, subjected to RH treatment, and then continuously cast to form the molten steel 1. Was used continuously. As described above, when performing the continuous casting in this series of operations, the temperature of the outer wall of the molten steel pot 1 (that is, the steel shell 1) and the driving device 3 of the sliding nozzle become the highest, so that the molten steel is supplied to the continuous casting facility. The surface temperature of the steel shell 1 and the surface temperature of the driving device 3 were measured at the supply position.
[0019]
As shown in FIG. 2, a heat insulating plate 4 is provided between the steel shell 1 and the driving device 3, and a gap is provided between the heat insulating plate 4 and the steel shell 1 to cool the lower end of the heat insulating plate 4. Gas 5 was supplied. The gap between the heat insulating plate 4 and the steel shell 1 was 40 mm, and the cooling gas 5 was flowed using nitrogen gas so that the linear flow rate was 5 m / sec. The driving device 3 used an electric motor. FIG. 4 shows a position A where the surface temperature of the iron shell 1 is measured and a position B where the surface temperature of the driving device 3 is measured. This is an invention example.
[0020]
On the other hand, as Comparative Example 1, as shown in FIG. 5, a series of operations is performed using the molten steel pot 1 that does not supply the cooling gas 5 without installing the heat insulating plate 4 between the steel shell 1 and the driving device 3. The surface temperature of the iron shell 1 and the surface temperature of the driving device 3 were measured. The other conditions are the same as those of the invention example, and the description is omitted. 5 (a) is a side view, and FIG. 5 (b) is a front view, and also shows a position A where the surface temperature of the steel shell 1 is measured and a position B where the surface temperature of the drive device 3 is measured.
[0021]
As a comparative example 2, as shown in FIG. 6, a series of operations were performed using a molten steel pot 1 to which no gap was provided between the steel shell 1 and the heat insulating plate 4 and to which the cooling gas 5 was not supplied. And the surface temperature of the driving device 3 were measured. The other conditions are the same as those of the invention example, and the description is omitted. 6 (a) is a side view, and FIG. 6 (b) is a front view, and also shows a position A where the surface temperature of the iron shell 1 is measured and a position B where the surface temperature of the driving device 3 is measured.
[0022]
FIG. 7 is a graph showing the relationship between the number of uses of the molten steel pot 1 and the surface temperature of the drive device 3, and FIG. 8 is a graph showing the relationship between the number of uses of the molten steel pot 1 and the surface temperature of the steel shell 1. is there. Here, the number of times the molten steel ladle 1 is used is the number of times the steel is received after repairing the refractory lining.
As is clear from FIGS. 7 and 8, in each of the invention example and the comparative examples 1 and 2, the wear of the refractory lining 9 progresses with an increase in the number of times the molten steel pot 1 is used. The temperature and the surface temperature of the shell 1 increase.
[0023]
Particularly, in Comparative Example 1, the surface temperature of the driving device 3 was higher than that of the inventive example and Comparative Example 2 due to the radiant heat from the steel shell 1.
In Comparative Example 2, the temperature rise due to radiant heat to the surface of the driving device 3 was suppressed by the heat insulating plate 4, but the surface temperature of the iron shell 1 was higher than in Comparative Example 1.
On the other hand, in the example of the invention, the surface temperature of the iron shell 1 could be kept low by the effect of the cooling gas 5, and as a result, the surface temperature of the drive device 3 could be kept low.
[0024]
【The invention's effect】
As described above, according to the present invention, in the molten metal container having the sliding nozzle and its driving device, not only the temperature of the driving device but also the temperature rise of the steel shell of the molten metal container opposed thereto. Can be suppressed, and the life of the molten metal storage container can be extended by extending the life of the drive device and preventing deformation of the steel shell.
[Brief description of the drawings]
FIG. 1 is a front view schematically showing an example of a molten metal container to which the present invention is applied.
FIGS. 2A and 2B are diagrams illustrating an example of an arrangement in a drive device storage box, wherein FIG. 2A is a side view and FIG.
FIG. 3 is a graph showing transition of a surface temperature of a steel shell and a surface temperature of a driving device.
FIGS. 4A and 4B are diagrams illustrating measurement positions of a surface temperature of a steel shell and a surface temperature of a driving device according to an example of the present invention, wherein FIG. 4A is a side view and FIG.
5A and 5B are diagrams illustrating measurement positions of a surface temperature of a steel shell and a surface temperature of a driving device in Comparative Example 1, in which FIG. 5A is a side view and FIG. 5B is a front view.
6A and 6B are diagrams illustrating measurement positions of a surface temperature of a steel shell and a surface temperature of a driving device in Comparative Example 2, wherein FIG. 6A is a side view and FIG.
FIG. 7 is a graph showing the relationship between the number of times a molten steel pot is used and the surface temperature of a driving device.
FIG. 8 is a graph showing the relationship between the number of times a molten steel pot is used and the surface temperature of a steel shell.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Molten metal storage container 2 Drive storage box 3 Drive 4 Insulation board 5 Cooling gas 6 Header 7 Iron shell 8 Molten metal (or molten steel)
9 Refractory lining A Measurement position of steel surface temperature B Measurement position of drive device surface temperature

Claims (2)

In a molten metal container having a sliding nozzle and a driving device therefor, an insulating plate is provided between the driving device and an area which is an outer wall of the molten metal container and is opposed to the driving device. A method for cooling an outer wall of a molten metal container, wherein the method is provided such that a gap is formed between the metal shell and the steel shell, and a cooling gas is caused to flow through the gap. In a molten metal container having a sliding nozzle and a driving device therefor, an insulating plate is provided between the driving device and an area which is an outer wall of the molten metal container and is opposed to the driving device. A molten metal container, which is provided so as to form a gap between the steel and the steel shell, and is provided with a gas ejection device for supplying a cooling gas to the gap.

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