JPH03189069A - Method for operating stopper for casting nozzle - Google Patents

Abstract

PURPOSE:To uniformly improve the quality of plural continuous casting ingots by rising nozzle stoppers to pour the molten metal within the same trough at the point of the time when the molten metal accumulates to some extent in the trough, then respectively independently controlling the respective stoppers at the time of continuously casting the molten metal to the plural casting ingots. CONSTITUTION:The plural nozzle stoppers 7 are risen to admit the molten metal into plural casting molds 3 at the point of the time when the molten metal, such as Cu alloy, accumulates in the trough 4. The positions of plug bodies 8 at the tips of the stoppers 7 are adjusted to adjust the amount of pouring from immersion nozzles 1 to an adequate amount when the ejection of the molten metal from the ejection ports 2 of the nozzles 1 without channeling is confirmed. The spacings between the plug bodies 8 and the inlets of the molten metal flow ports of the trough for the respective stoppers are adjusted by operating the rod bodies of the upper handles 10 of the nozzle stoppers 7 by hook bars to uniformize the volume of the molten metals in the respective casting molds 3 and thereafter the continuous casting operation is started if the bottom of the trough 4 is deformed by the weight and heat of the molten metal. The high-quality continuous casting ingots 15 uniformly grown with solidified shells 16 of the molten Cu alloy in the respective casting molds are thereby obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a continuous or semi-continuous casting immersion method in which molten metal is supplied to a mold with an open top that is used when continuously casting slabs of copper-based alloys. The present invention relates to a method of operating a stopper for a nozzle, and particularly to a method of operating a stopper for an immersion nozzle that can stabilize operations and improve the quality of ingots in continuous or semi-continuous casting methods in which molten metal is supplied to a mold with a large number of strands.

[Conventional technology]

In the continuous or semi-continuous casting method, the molten metal in the tundish or the molten metal discharged from the melting furnace into the gutter is injected into a water-cooled copper mold, cooled in the mold to solidify the molten metal sequentially, and the slab is continuously removed from the mold. This is a method of pulling it out.

In order to stably cast slabs with few casting defects using continuous or semi-continuous casting methods, the amount of molten metal supplied into the mold must be kept constant in order to prevent mold flags from getting caught up in the slab. is important.

Generally, as a mold for continuous or semi-continuous casting, a short through-hole mold is used which is composed of a pair of opposing short mold pieces and a pair of long mold pieces.

When supplying molten metal from a tundish or gutter into a mold, a submerged nozzle is attached to the bottom of the tundish or gutter, and the molten metal is jetted from the bottom of the nozzle and injected into the mold.

Conventionally, there are several types of jet nozzle shapes for this immersion nozzle, and a nozzle suitable for the type of molten metal to be cast and the shape of the mold is used. For example, when casting slab slabs of copper-based alloys by continuous or semi-continuous casting, it is necessary to
The use of the inverted T-shaped nozzle shown in the figure has become common.

This nozzle is as shown in FIGS. 2 and 3.

Generally, the nozzle 1 has a cylindrical spout 2 along the center line of a cross section perpendicular to the casting direction. is attached to.

A nozzle stopper 5 is provided for the nozzle 1, and the conventional nozzle stopper 5 is operated up and down by an air cylinder or hydraulic cylinder 6 attached to the tundish or gutter 4, as shown in FIG. It looks like this.

Also, as this type of device, Japanese Patent Application Laid-Open No. 46-4358,
JP-A-46-5501, JP-A-49-92631,
The one described in JP-A No. 50-142432 is known.

[Problem to be solved by the invention]

However, all of the conventional nozzle stopper control devices described above open and close the nozzle by directly moving the nozzle stopper up and down using an air cylinder or hydraulic cylinder to control the amount of molten metal supplied. If the nozzle and nozzle stopper are bent downward due to weight and high heat, and the center of the nozzle and nozzle stopper is misaligned, the supply of molten metal to the mold cannot be controlled, and the nozzle and nozzle stopper cannot be completely closed at the end of casting. There was a problem.

In addition, the nozzle stopper needs to be fully opened or fully opened quickly at the start and end of casting, but with conventional control devices, there is a slight time lag and it is not possible to maintain the same amount of molten metal into the mold. There was a drawback.

Furthermore, in the conventional control device, when the number of strands (the number of ingots to be simultaneously cast) increases, there is a problem in that it is difficult to independently finely adjust each nozzle stirrer.

The present invention has been made in view of the above-mentioned circumstances, and can simply and easily operate a large number of nozzle stoppers all at once or each independently.

The object of the present invention is to provide a method of operating a stopper for a continuous or semi-continuous casting nozzle, which can further stabilize continuous or semi-continuous casting operations and improve the quality of slabs.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a method for discharging molten metal into a gutter in a continuous or semi-continuous casting method.

A large number of nozzles are fully opened by nozzle stoppers provided correspondingly to each nozzle, and with a certain amount of molten metal accumulated in the gutter, the nozzle stoppers are fully opened all at once to supply melt to a large number of molds, and then the nozzle stopper It is characterized by independently controlling each mold to equalize the amount of molten metal supplied to each mold, and then starting drawing all at once. The feature is that a large number of nozzle stoppers can be operated independently to fully open the nozzle.
Furthermore, after the start of drawing, each nozzle stopper is operated independently to control the molten metal supply amount to match the casting speed.

[Effect]

Next, to explain the operation of the present invention, when dispensing molten metal into a gutter in a continuous or semi-continuous casting method, a support holding a large number of nozzle stoppers is rotated by a driving means such as a hydraulic cylinder, and Each nozzle stopper is operated independently to fully open a large number of nozzles using the corresponding nozzle stopper, so that a certain amount of molten metal has accumulated in the gutter, and then the nozzle is opened so that the immersion nozzle hole does not become clogged. The nozzle stopper is fully opened to feed and damage a large number of molds at once, and the nozzle stoppers are independently controlled to feed the nozzle into each mold. 8
? After making the amounts of a and m the same, start pulling out all at once. In this way, by keeping the same amount of molten metal, we can prevent breakouts and variations in the range of the unsteady casting area at the bottom of the slab, and perform stable operations. Furthermore, after the start of drawing, each nozzle stopper can be operated independently. and casting;
The quality of slabs is improved by controlling the amount of molten metal supplied to suit the conditions.

Further, when the casting is finished, the flow is stopped all at once.

In this way, when a large number of solidified slabs are continuously drawn vertically downward in continuous or semi-continuous casting, the amount of molten metal in each of the many molds may differ slightly, In such a case, the amount of molten metal flowing in when the nozzle stopper is opened can be finely adjusted by slightly rotating the nozzle stopper by operating the handle on the top of the nozzle stopper. The rotation operation part can also be automatically operated by a device other than the handle.

Furthermore, even if the tundish or gutter is deformed due to the weight and heat of the molten metal and the distance or center between the nozzle stopper stopper and the nozzle opening at the bottom of the gutter is slightly misaligned, the molten metal can be poured into a large number of molds by operating the handle. It feeds evenly and stops completely at the end of casting.

〔Example〕

Next, a method of operating the stopper for a continuous or semi-continuous casting nozzle according to the present invention will be explained by way of an example with reference to the drawings.

1 and 2 show an embodiment of the present invention, in which a two-hole immersion nozzle 1 has a cylindrical spout 2 along the center line of a cross section perpendicular to the casting direction. , this immersion nozzle 1 is attached to the bottom of the gutter 4, and a hole 4a bored in the bottom of the gutter 4 communicates with the flow path 1a leading to the spout 2 of the immersion nozzle 1. .

Moreover, the upper part of this hole 4a, ie, the bottom part of the gutter 4, is formed into a funnel-shaped valve seat 4b.

On the other hand, the nozzle stopper 7 that opens or closes the valve seat 4b has a stopper part 8 made of a carbon material at its tip and an intermediate part in which a male screw part 9 is formed.

A handle part 1 has a plurality of rods 10a protruding from its upper part.
It is composed of 0. The male threaded portion 9 is connected to the horizontal rod 11 of the support 11 holding the nozzle stopper 7.
It is screwed onto a female threaded portion 12 provided in a. Further, the horizontal rod 11a of the support body 11 is provided with support rods 11b at both ends, and is rotated about the rotation center P by a hydraulic cylinder 13.

Note that reference numeral 14 is a table that supports the molten metal in the mold 3 at the start of casting, and this table 14 is moved up and down by a hydraulic cylinder (not shown).

In this embodiment, the number of strands shown in FIG. 4 is not limited to three, but can be applied to a large number of strands, such as two or more.

Next, the operation of this embodiment will be described. A copper-based alloy as a raw material is melted in a low-frequency groove-type induction heating melting furnace, and the molten metal is tapped into the gutter 4.

To dispense the hot water, first operate the hydraulic cylinder 13 to fully open the gap between the nozzle stopper 7 and the upper funnel-shaped valve seat 4b of the hole 4a communicating with the immersion nozzle 1, and then dispense the hot water to @4 so that some amount remains in the gutter. When the molten metal is fully opened all at once in a state where molten metal has accumulated, the molten metal flows into the nozzle 1 through between the stoppers 8 at the tips of the multiple nozzle stoppers 7 and the valve seats 4b corresponding to each one, as shown in FIG. As shown in the figure, the liquid enters the mold 3 through the spout 2 of the nozzle 1, is supported by the table 14, and is stored in the mold 3.

With a certain amount of molten metal accumulated in the gutter, the upper funnel-shaped valve seat 4 of the hole 4a communicating with the nozzle 1-flange 7 and the immersion nozzle 1 is opened.
The reason for fully opening the gap with b is to prevent the flow path 1a of the nozzle 1 from clogging due to solidification of the molten metal, and to keep the amount of molten metal supplied to each mold 3 constant, so that the flow path 1a of the nozzle 1 is fully opened at the same time. This is to prevent breakout from occurring when drawing out the solidified slabs all at once. When it is confirmed that the molten metal is ejected from the ejection port 2 of the nozzle 1 without drifting, the hydraulic cylinder 13 is operated again, and the nozzle stopper 7 is activated.
The plug body part 8 at the tip of the valve seat 4b corresponding to each
The nozzle stopper 7 reaches the gap position between the plug body part 8 and the valve seat 4b where the amount of molten metal flowing into the nozzle 1 becomes appropriate.
descend.

At this time, the bottom of the gutter 4 may be deformed from the normal state shown in Fig. 5 to the one shown in Fig. 6 due to the weight and heat of the molten metal, but even if such deformation occurs, the nozzle The plurality of rods 10a of the upper handle 10 of the stopper 7 are operated by the hook rod 17, and the nozzle stopper 7 is rotated independently to adjust the gap between the plug body 8 at the tip and the valve seat 4, so that each rod body 10a is adjusted to a predetermined position. The opening degree can be ensured.

After the molten metal supplied to the mold 3 in the same amount as described above is heated and starts to solidify, if the table 14 is moved vertically downward all at once, the molten metal will not break out as shown in Fig. 5 or 3. As shown in FIG. 6, casting of the slab 15 can be started while the solidified shell 16 is being formed.

Further, even after the pulling is started, even if the gap between the nozzle stopper 7, the stopper portion 8, and the valve seat 4io of the gutter 4 differs depending on each strand due to the deformation of the gutter 4, the handle 10 can be operated. By rotating the nozzle stoppers 7 independently, each can secure a predetermined opening degree.

In this way, when the slab 15 reaches a predetermined length and casting is completed, the hydraulic cylinder 13 is activated and each nozzle can be easily fully opened by the nozzle stopper 7. Even if the gap and center of the plug body 8 of the nozzle stopper 7 and the valve seat 4b are slightly misaligned due to the It can be stopped completely.

Furthermore, if it becomes difficult to continue casting due to various troubles occurring during casting, the nozzle stopper 7 is lowered by an independent rotation operation, and the supply of molten metal is stopped while casting of other strands continues. can do.

〔Effect of the invention〕

According to the present invention described above, when pouring molten metal into a gutter when casting a large number of slabs at the same time, a large number of nozzles are fully opened by nozzle stoppers provided in correspondence with each other, and the molten metal is poured into the gutter. Since a certain amount of molten metal has accumulated, the nozzle stopper is fully opened all at once to supply the melt to a large number of molds, so it is possible to prevent the molten metal from solidifying and clogging the holes of the two-hole immersion nozzle immediately after supplying the metal, and the nozzle stopper can be opened individually. Since the amount of molten metal supplied to each mold is controlled independently and the amount of molten metal supplied to each mold is equalized and then the withdrawal is started all at once, it is possible to prevent breakouts and variations in the range of the unsteady casting area at the bottom of the slab. Stable operation is now possible, and after the start of drawing, each nozzle stopper is operated independently to control the molten metal supply amount to match the casting speed, improving the quality of the slab. can be stopped completely.

In addition, since a large number of nozzle stoppers can be operated all at once or each independently, it is easy to supply hot water to each mold in various ways, and it is also possible to prevent the tundish or gutter from deforming downward due to the weight and high heat of the molten metal. Since each nozzle stopper is finely adjusted individually, the supply of molten metal to each mold can be controlled to the same amount, and the quality of each slab can be improved.

[Brief explanation of drawings]

FIG. 1 is a side view of an embodiment of the present invention, FIG. 2 is a front sectional view of the mold, and FIG. 3 is a submerged nozzle. (a) is a longitudinal sectional view, (b) is a side view, and (c) ) is a cross-sectional view, FIG. 4 is a front view, FIGS. 5 and 6 are front sectional views, and FIG. 7 is a sectional view of a conventional example. l...Immersion nozzle, 4...Gutter, 8...Bung body part, 1o...Handle part. 12...Female thread part,

Claims (3)

[Claims] (1) When dispensing molten metal into a gutter in continuous or semi-continuous casting, a large number of nozzles are fully closed by corresponding nozzle stoppers, and a certain amount of molten metal accumulates in the gutter. The nozzle stopper is fully opened to supply molten metal to a large number of molds, and the nozzle stoppers are each independently controlled to equalize the amount of molten metal supplied to each mold, and then drawing is started all at once. How to operate a stopper for a casting nozzle. (2) The stopper for a casting nozzle according to claim 1, characterized in that when a large number of nozzles are brought into a fully closed state by a nozzle stopper, the large number of nozzle stoppers are each independently operated to be brought into a fully closed state. Method of operation. (3) The method of operating a stopper for a casting nozzle according to claim 1, wherein after the start of drawing, each nozzle stopper is operated independently to control the molten metal supply amount to match the casting speed.