JPS58116960A - Vessel for molten metal - Google Patents

Abstract

PURPOSE:To remove slag stably and efficiently without changing operating conditions by installing a holed plate in the slag discharging port on the side wall of a tundish, and connecting a slag sucking nozzle into the opening of the holed plate. CONSTITUTION:When the thickness of the slag layer 1 in a tundish increases to prescribed thickness, the operator confirms that the level of the slag layer in the tundish is in the position of a slag discharging port 11. If the slag layer is below or above said position, the inflow velocity of the molten metal from a ladle is controlled to match the level of the slag layer at the port 11; thereafter, the operator operates a holed sliding plate 4 in an opening direction, thereby removing only the slag safely through the port 11 by a vacuum scavenging method for slag (VSC). Thus, the slag is controlled to the prescribed thickness and the casting is continued stably and smoothly.

Description

[Detailed Description of the Invention] With the development of the continuous casting method, so-called continuous casting, in which the molten metal is continuously introduced into the hook while tapping continues, has reached the stage of practical use. It is well known that as the amount of slag increases, more slag flows into the tundish, and contamination of the molten metal with slag inclusions progresses1. Reduction of slag inclusions in continuous casting materials This is an important issue for the expansion of continuous O casting of high-grade steel], and in particular, high cleanliness is required for Noib materials for UO and IRW, as well as tinplate for DI cans for food cans. Many OIM investigations have been conducted in the past as to the origin of large inclusions, and slag within the tanditsu has been cited as the factor with the highest contributing factor. In particular, when promoting multiple casting in consideration of productivity and cost, the influence of slag is noticeable, and in order to prevent this, conventionally, (
1) A weir is installed inside the tundish, (2) a method for preventing slag from being thrown in by eliminating the drop position of the injected flow from the ladle, (3) a slag overflow method with an opening at the top of the side wall of the tundish, (4) A method for eliminating slag noccum from above tandates/yu (hereinafter referred to as ■SC) has been implemented.

However, all of the above four measures have the following drawbacks.

When a weir is installed inside the tundish in (1), the weir installed inside the tundish promotes the surfacing of slag, i.e. large inclusions, mixed into the molten metal.Once slag is mixed in, it is extremely difficult to remove. If one bottle is provided, molten metal will remain in the tundish even after pouring, resulting in loss.

Furthermore, it is difficult to prevent the O-sludder from getting caught above the nostle for casting chicks.

(2) The method of preventing knock-in by removing slag from the falling position of the pouring stream is to prevent the molten metal surface in the tundish from separating from the pouring nozzle, that is, the long nozzle from the ladle at the joint in continuous casting. This is to prevent the floating slag directly below the nozzle from accumulating, but its effectiveness decreases as the number of castings increases and the thickness of the floating slab increases.

(3) A slag layer with an opening at the top of the side wall of the tandish
The no-flow one type is a method for dealing with the increase in the thickness of the strip when the number of casts increases continuously. However, this method not only causes a loss of feet due to the outflow of the molten metal, but also has low removal efficiency, requires maintenance of large overflow troughs, and lowers the molten metal surface to normal use level.] It has drawbacks such as safety issues because it is raised to a high position.

(Tandates v3-ff of 4! The slag removal method from above the hot water level is the slag removal method using a vacuum suction device (Unexamined Japanese Patent Application Ws52-5653, Unexamined Japanese Patent Application V852zty
oe) Insert the suction nozzle into the tanditsh,
This is a method in which the slag is removed by suction by bringing it close to the molten metal surface. According to this method, it is possible to remove the slag with good RAIk property, but the O slag O conduit from the VsC main body to the nozzle part is Since movement and rotational movement are required, kat, h
However, there remains a safety problem during sampling or scooping operations on the tundish (because the tundish is occupied by the tundish during the suction operation).

The advantage of the present invention is to solve the above-mentioned drawbacks (1) to (4)O. In order to achieve this object, the present invention provides a perforated plate at the slag discharge port that can be installed in a regular bathtub. The device is characterized in that it is installed so that it can be moved, and that a vsca nozzle is connected to the opening of the perforated plate so that it can be drawn in an appropriate manner.

The present invention@〇1 example will be described below.

JlillQ is a molten metal container 0 showing an example of this invention @0
1 [111 is an enlarged sectional view.

In the figure, numeral 3 indicates the side wall of the tundish main body, and a slag discharge port 11 is provided with a sleeve brick near the normal level of the thickness of the slag layer l. A perforated sliding plate 4 is provided at the slab discharge port 11.
and a perforated fixing plate 5 are arranged, and the vsca inlet nozzle γ is connected to the vSC main body through a simple detachable joint.

For the perforated fixing plate 5, it is necessary to use a fireproof material with excellent slag wettability, such as Zr or Arunna corundum. It is preferable that the Km slag discharge port 110 for large objects (sleeve bricks in this example), the perforated plate 4, and the container of the main body 3 of the makutan dateshier body 3 be configured to be replaceable because they are subject to significant erosion by slag.

In the present invention, the slag discharge port is installed on the side wall of the tundish O, for example, at the molten metal level for regular use in the tundish O, or at a position near the top thereof. Without any change operation, check that the slag layer level is at the discharge port 11 position with any tie setting. It is possible to remove any amount of slag by simply opening and closing the door.

Furthermore, since the perforated fixing plate 5KVSC11 pulling nozzle 7 is connected, the conventional vSC method is a large lid equipment that requires turning up and down, but according to the present invention, the amount of operation is reduced because it is installed on the side wall. It is possible to make the lid smaller, it is advantageous in terms of safety since there is no need to work above the tundish, and it is possible to efficiently remove the cis lag by the perforated sliding plate 4 with good workability.

Regarding the embodiment of the present invention configured in this way, Section tg
The following description will be made based on a typical embodiment of the present invention shown in .

First, it is confirmed that the slag layer thickness in the tundish has increased to a predetermined thickness and that the slag layer level in the tundish is at the slag discharge port 110 position.

Also, if the slag layer is too much or too little for the wrinkle position, remove it from the ladle! After controlling the hot water inflow speed and aligning the level of the 7 layers of slag to meet the slag discharge port 11, operate the perforated sliding plate 4 in the opening direction to safely drain only the slag from the slag discharge port 11.
The slag is removed by the slag, and the slag is controlled to a predetermined thickness to continue stable and smooth casting.

Although the above explanation has been given using a tundish as an example, it can be similarly applied to OIW molten metal containers such as a torpedo car, a smelting furnace, and a ladle depending on the respective uses.

The present invention provides a device configured as described above, so that (1) slag can be safely and smoothly removed from the side wall opening of the molten metal container without significantly changing the molten metal level in the container; becomes. (2) Compared to conventional methods, there is an IIO effect that allows the vSC equipment to be made smaller, and slag D can be removed stably and efficiently without changing operating conditions.
The benefits are significant.

[Brief explanation of the drawing]

Figure #I1 is an enlarged cross-sectional view of a main part of a molten metal container showing an embodiment of the present invention. 1... Slag, 2... Molten metal, 3... Tuff dish main body side wall, 4... Perforated sliding plate, 5... Perforated fixing plate, 6... vSC main body 9. ... Perforated slide plate for bath water control, lO... Immersion nozzle, 11... Sleeve brick for slag outlet. Agent: Patent Attorney Masaaki Akizawa Kosen (2 people)

Claims (1)

[Claims] (1) A perforated plate is slidably provided at the slag discharge port provided on the side wall of the molten metal container, and a true g! A molten metal container characterized in that the tips of the suction nozzles of the suction cap are arranged in a connected manner so that the suction nozzle can be delayed.