JPH01201413A - Method of steel tapping from refining furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for preventing molten slag floating on the surface of VFI steel in the furnace from flowing out after the completion of refining in a tiltable refining furnace such as a converter. The present invention provides a method for tapping steel from a refining furnace, which allows only molten steel to be discharged.

[Prior art] For example, molten steel that has been refined in a converter is moved downward through the tap by tilting the furnace so that the tap provided on the upper side of the furnace body faces downward. It is discharged into a ladle located. At this time, a part of the molten slag floating on the surface of the molten steel mixes with the molten steel and flows into the ladle together with the molten steel. As described above, if molten slag is mixed into the molten steel discharged into the ladle, the product quality will deteriorate and the casting operation will also be hindered.

[Problem to be solved by the invention]

Therefore, in the past, workers monitored the flow of molten steel flowing out from the tap port of the converter into the ladle, and if molten slag got mixed into the flow of molten steel, they would stop the flow of steel. was. However, with this method, it is not possible to reliably prevent molten slag from entering and flowing out, and in particular, in the case of non-oxidized steel tapping, the space between the tap hole and the ladle is shielded by a cover, and the molten slag cannot be reliably prevented from flowing out. The above method was impossible to implement because the flow of molten steel from the steel mouth could not be visually observed.

In addition, slag balls having a specific gravity between that of molten steel and molten slag are suspended in the molten metal directly above the tap port of the converter,
At the final stage of tapping when molten slag flows out, attempts have been made to close the tapping port with slag balls to prevent the molten slag from flowing out, but even this method does not reliably prevent the molten slag from flowing out. I can't.

Therefore, an object of the present invention is to discharge molten steel that has been refined from a refining furnace such as a converter through its tapping port.
Molten slag floating on the surface of molten steel does not flow out.
The object of the present invention is to provide a method capable of discharging only molten steel.

[Means to solve the problem]

In this invention, an electromagnetic pump is provided on the outside of the lower part of the tap hole provided at the upper part of the furnace body of a tiltable refining furnace, and is brought into contact with the tap hole, so that when tapping the steel, the electromagnetic pump is placed on the surface of the molten steel in the furnace. The mental furnace is tilted until the molten slag is located directly below the tap, and then the! Activate the magnetic pump and its N
It is characterized in that only the molten steel in the furnace is pumped out into the tapping port by Em force, and the molten steel in the furnace is thus discharged through the tapping port.

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a schematic vertical sectional view of a converter showing one embodiment of the present invention. As shown in FIG. 1, a tapping port 2 is provided in the upper part of the furnace body of the converter l. An electromagnetic pump 3 is provided outside the lower part of the tapping port 2. The electromagnetic pump 3 is
It is in contact with the outside of the lower part of the tap 2 and the furnace wall at the bottom of the tap 2.

When the refining in the converter 1 is finished and the steel is tapped, the molten steel 4 in the furnace is
The furnace body is tilted until the molten slag 5 floating on the surface of the furnace body is located directly below the tapping port 2 where it does not flow out from the tapping port 2.

Next, when the electromagnetic pump 3 is operated, only the molten steel 4 is pumped into the tap hole 2 and discharged through the tap hole 2 due to its electromagnetic force. At this time, the molten slag 5 is not affected by the electromagnetic force because of its low magnetism, and therefore is not pumped out to the tapping port 2.

In this manner, when the situation inside the furnace is lowered due to the discharge of molten steel 4, the furnace body is sequentially tilted until it is located directly under the tapping port 2 to such an extent that the molten slag 5 does not flow out from the tapping port 2.

In this way, only the molten steel 4 in the furnace can be completely discharged through the tapping port 2.

According to tests conducted by the present inventors, it has been found that ! The preferable electromagnetic force of the magnetic pump 3 is:
It is about 1500 Gauss.

(Example〕 Next, the present invention will be explained using examples.

Yong! There is an electromagnetic force of 15% on the outside of the taphole of a 250T converter.
A 00 Gauss electromagnetic pump was installed. For tapping, the furnace body was tilted until the molten slag floating on the surface of the molten steel in the furnace was located directly below the tapping port, and then the electromagnetic pump was activated. The conditions for the molten steel and the ITM pump at this time are as follows.

Temperature of molten steel: 1650-1700℃ Specific gravity of molten steel Near, Og/cd Radiation of tapping flow: 17c+m Height of tapping flow: 11cm Phase voltage of electromotive crab 7016A inductor induced by magnetic flux in coil: 15 ．． '786 V Molten steel movement speed: 8.
12cm/S As a result, only molten steel was discharged into the ladle, and molten slag did not flow out.

[Effects of the Invention] As described above, according to the present invention, only molten steel can be discharged from a refining furnace such as a converter through its tapping port, and therefore product quality does not deteriorate. This brings about an industrially useful effect that allows casting work to be carried out smoothly.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a schematic vertical sectional view of a converter in a tapped state showing an embodiment of the present invention.
2... Steel tapping port, 3... Electromagnetic pump,
4... Molten steel, 5... Molten slag.

Claims (1)

[Claims] An electromagnetic pump is installed on the outside of the lower part of the tapping port provided on the upper part of the furnace body of the tiltable refining furnace in contact with the tapping port, and when tapping, the molten slag floating on the surface of the molten steel in the furnace is The refining furnace is tilted until it is located directly below the tapping port, and then the electromagnetic pump is activated, and only the molten steel in the furnace is pumped out into the tapping port by the electromagnetic force. A method for tapping steel from a refining furnace, characterized in that the steel is discharged through the tapping port.