JP2021126664A

JP2021126664A - Immersed nozzle

Info

Publication number: JP2021126664A
Application number: JP2020021131A
Authority: JP
Inventors: 雅弘階戸; Masahiro Kaito; 正成川瀬; Masashige Kawase
Original assignee: Akechi Ceramics Co Ltd
Current assignee: Akechi Ceramics Co Ltd
Priority date: 2020-02-12
Filing date: 2020-02-12
Publication date: 2021-09-02

Abstract

To provide immersed nozzles 10, 10A which can stabilize a flow condition of molten steel in a mold and can effectively prevent mold powder entrainment.SOLUTION: Each of through holes 15 is composed of an internal through part 15a formed on a molten steel flow path 13 side, and an external through part 15b formed on a discharge port 16 side and communicating with the inside through part 15a. The internal through 15a reaches an outer periphery part 12b. An inner diameter of the external through part 15b is gradually expanded to the discharge port 16 from a communication part with the internal through part 15a. When jet streams of molten steel pass through the through holes and are discharged into the mold from the discharge port 16, they scatter along the external through part 15b expanding to the discharge port 16, so that flow rate of the jet streams discharged from the discharge port 16 is decelerated and is equalized as schematically shown by an arrow in Figure 4. Thus, it is possible to suppress stagnation occurring at an edge part on an opening end surface of the discharge port 16, stabilize a flow state of the molten steel in the mold, and prevent entrainment of mold powder into the molten steel.SELECTED DRAWING: Figure 2

Description

本発明は溶鋼をタンディッシュからモールド内へ注入するとき溶鋼が空気に触れて酸化しないようにするため、タンディッシュノズルに接続してモールド内の溶鋼に浸漬する浸漬ノズルに関する。 The present invention relates to a dipping nozzle that is connected to a tundish nozzle and immersed in the molten steel in the mold so that the molten steel does not come into contact with air and oxidize when the molten steel is injected into the mold from the tundish.

この種の浸漬ノズル１は、図５及び図６に示すように、一端にタンディシュノズルに接続される接続口２を設け、他端に底部３を設け、中心部に接続口２から底部３に至る溶鋼流路４を形成した有底の円筒構造を有する。そして、底部３の近傍の周壁を貫通する２本の貫通穴５で２個の吐出口６が形成されている。各貫通穴５は円形の断面形状を有し、２個の吐出口６は溶鋼流路４を挟んで対向するように配置されている。各貫通穴５は吐出口６から溶鋼が吐出するときにモールドパウダーを溶鋼中に巻き込まれないようにするため、斜め下向きに形成されている。 As shown in FIGS. 5 and 6, this type of immersion nozzle 1 is provided with a connection port 2 connected to a tundish nozzle at one end, a bottom 3 at the other end, and a connection port 2 to a bottom 3 at the center. It has a bottomed cylindrical structure in which the molten steel flow path 4 leading to is formed. Then, two discharge ports 6 are formed by two through holes 5 penetrating the peripheral wall in the vicinity of the bottom portion 3. Each through hole 5 has a circular cross-sectional shape, and the two discharge ports 6 are arranged so as to face each other with the molten steel flow path 4 interposed therebetween. Each through hole 5 is formed diagonally downward so that the mold powder is not caught in the molten steel when the molten steel is discharged from the discharge port 6.

この浸漬ノズル１では、溶鋼が斜め下向きの強いジェット流となって吐出口６から吐出する。
しかして、浸漬ノズル１の縦断面形状において辺となって表れる貫通穴５の内周面５ａと、横断面形状において辺となって表れる内周面５ｂはいずれも直線となる。そのため、溶鋼の吐出流は大部分が平行になり、図７に矢印で模式的に示すように底部３に近いほど流速が速くなり、流速分布が不均一になっている。そのため、モールド内の溶鋼の流動状態が不安定となり、吐出口６の開口端面の上側縁部に淀みが発生し、モールドパウダーが溶鋼中に巻き込まれてしまう。 In the immersion nozzle 1, the molten steel becomes a strong jet flow diagonally downward and is discharged from the discharge port 6.
Therefore, both the inner peripheral surface 5a of the through hole 5 appearing as a side in the vertical cross-sectional shape of the immersion nozzle 1 and the inner peripheral surface 5b appearing as a side in the cross-sectional shape are straight lines. Therefore, most of the discharge flows of the molten steel are parallel, and as shown by arrows in FIG. 7, the closer to the bottom 3, the faster the flow velocity, and the flow velocity distribution becomes non-uniform. Therefore, the flow state of the molten steel in the mold becomes unstable, stagnation occurs in the upper edge portion of the opening end surface of the discharge port 6, and the mold powder is caught in the molten steel.

一方、特許第４６６５０５６号公報には、モールド内の溶鋼の流動状態を安定させてモールドパウダーの巻き込み防止を図った浸漬ノズルが開示されている。この浸漬ノズルは、吐出口を形成する貫通穴の断面形状を内径が内端面から外端面に向けて漸減するラッパ形状に形成されている。
しかしながら、貫通穴をラッパ形状にしたこの浸漬ノズルも、満足できるモールドパウダーの巻き込み防止効果を奏するものではない。 On the other hand, Japanese Patent No. 4665056 discloses a dipping nozzle that stabilizes the flow state of the molten steel in the mold and prevents the mold powder from being entrained. The immersion nozzle is formed in a trumpet shape in which the inner diameter of the through hole forming the discharge port is gradually reduced from the inner end surface to the outer end surface.
However, even this immersion nozzle having a trumpet-shaped through hole does not have a satisfactory effect of preventing mold powder from getting caught.

特許第４６６５０５６号公報Japanese Patent No. 4665056

本発明は上記問題点に鑑み、モールド内の溶鋼の流動状態を安定させ、モールドパウダーの巻き込みを効果的に防止できる浸漬ノズルを提供することを目的とする。 In view of the above problems, an object of the present invention is to provide a dipping nozzle capable of stabilizing the flow state of molten steel in a mold and effectively preventing entrainment of mold powder.

本発明に係る浸漬ノズルは、一端にタンディッシュとの接続口を設け、他端に底部を設け、中心部に接続口から底部に至る溶鋼流路を形成した有底の円筒構造を有し、溶鋼通路に達する貫通穴で底部近傍の周壁に吐出口を形成した浸漬ノズルであって、
各貫通穴が溶鋼流路側に形成された内側貫通部と、吐出口側に形成され内側貫通部に連通する外側貫通部で構成され、
外側貫通部をその内径が内側貫通部との連通部から吐出口に向かって漸増するように拡開させたことを特徴とする。 The immersion nozzle according to the present invention has a bottomed cylindrical structure in which a connection port with a tundish is provided at one end, a bottom portion is provided at the other end, and a molten steel flow path from the connection port to the bottom portion is formed in the central portion. A dipping nozzle with a through hole that reaches the molten steel passage and a discharge port formed on the peripheral wall near the bottom.
Each through hole is composed of an inner penetrating portion formed on the molten steel flow path side and an outer penetrating portion formed on the discharge port side and communicating with the inner penetrating portion.
The outer penetrating portion is widened so that its inner diameter gradually increases from the communicating portion with the inner penetrating portion toward the discharge port.

本発明によれば、溶鋼のジェット流が貫通穴を通過して吐出口からモールド内に吐出するとき、吐出口に向かって拡開する外側貫通部に沿って拡散するので、吐出口から吐出するジェット流の流速が減速されて均一化する。そのため吐出口の開口端面の縁部に淀みが発生するのを抑制でき、モールド内の溶鋼の流動状態が安定するので、モールドパウダーの溶鋼中への巻き込みを防止できる。 According to the present invention, when the jet flow of molten steel passes through the through hole and is discharged from the discharge port into the mold, it diffuses along the outer penetration portion that expands toward the discharge port, so that the jet flow is discharged from the discharge port. The flow velocity of the jet flow is decelerated and made uniform. Therefore, it is possible to suppress the occurrence of stagnation at the edge of the opening end surface of the discharge port, and the flow state of the molten steel in the mold is stabilized, so that the mold powder can be prevented from being entrained in the molten steel.

本発明の実施例に係る浸漬ノズルを示す斜視図である。It is a perspective view which shows the immersion nozzle which concerns on embodiment of this invention. 同浸漬ノズルを示す縦断面図である。It is a vertical cross-sectional view which shows the immersion nozzle. 図２の３−３線から切断した断面図である。It is sectional drawing which cut from the 3-3 line of FIG. 同浸漬ノズルの吐出口から吐出するジェット流の流速分布を示す説明図である。It is explanatory drawing which shows the flow velocity distribution of the jet flow discharged from the discharge port of the immersion nozzle. 従来の浸漬ノズルを示す縦断面図である。It is a vertical cross-sectional view which shows the conventional immersion nozzle. 図５の７−７線から切断した断面図である。It is sectional drawing which cut from the 7-7 line of FIG. 同浸漬ノズルの吐出口から吐出するジェット流の流速分布を示す説明図である。It is explanatory drawing which shows the flow velocity distribution of the jet flow discharged from the discharge port of the immersion nozzle.

以下に本発明を図面に基づき説明する。図１〜図３には本発明の実施例に係る浸漬ノズル１０が示されている。当該浸漬ノズル１０は、有底の円筒構造を有し、一端にタンディッシュノズルとの接続口１１が設けられ、他端に底部１２が設けられている。そして、中心部に接続口１１から底部１２に至る溶鋼流路１３が形成されている。また、底部１２の近傍の周壁１４には溶鋼流路１３に通じる２本の貫通穴１５によって２個の吐出口１６が形成されている。２本の貫通穴１５は、吐出口１６が溶鋼流路１３を挟んで対向するように配置されている。 The present invention will be described below with reference to the drawings. 1 to 3 show the immersion nozzle 10 according to the embodiment of the present invention. The immersion nozzle 10 has a bottomed cylindrical structure, and is provided with a connection port 11 for connecting to a tundish nozzle at one end and a bottom portion 12 at the other end. A molten steel flow path 13 from the connection port 11 to the bottom 12 is formed in the central portion. Further, two discharge ports 16 are formed on the peripheral wall 14 near the bottom portion 12 by two through holes 15 leading to the molten steel flow path 13. The two through holes 15 are arranged so that the discharge ports 16 face each other with the molten steel flow path 13 interposed therebetween.

底部１２の底面は中央の平たん部１２ａと平たん部１２ａの外周部１２ｂから成り、外周部１２ｂは上向きに傾斜している。
各貫通穴１５は溶鋼流路１３側に形成された内側貫通部１５ａと、吐出口１６側に形成され内側貫通部１５ａに連通する外側貫通部１５ｂで構成されている。そして、内側貫通部１５ａは外周部１２ｂに達している。また、外側貫通部１５ｂの内径は内側貫通部１５ａとの連通部から吐出口１６に向かって漸増するように拡開している。 The bottom surface of the bottom portion 12 is composed of a central flat portion 12a and an outer peripheral portion 12b of the flat portion 12a, and the outer peripheral portion 12b is inclined upward.
Each through hole 15 is composed of an inner through portion 15a formed on the molten steel flow path 13 side and an outer through portion 15b formed on the discharge port 16 side and communicating with the inner through portion 15a. The inner penetrating portion 15a reaches the outer peripheral portion 12b. Further, the inner diameter of the outer penetrating portion 15b is widened so as to gradually increase from the communicating portion with the inner penetrating portion 15a toward the discharge port 16.

本実施例に係る浸漬ノズル１０によれば、溶鋼のジェット流が貫通穴１５を通過して吐出口１６からモールド内に吐出するとき、吐出口１６に向かって拡開する外側貫通部１５ｂに沿って拡散するので、図４に矢印で模式的に示すように、吐出口１６から吐出するジェット流の流速が減速されて均一化する。そのため、吐出口１６の開口端面の縁部に淀みが発生するのを抑制でき、モールド内の溶鋼の流動状態が安定し、モールドパウダーの溶鋼中への巻き込みを防止できる。 According to the immersion nozzle 10 according to the present embodiment, when the jet flow of molten steel passes through the through hole 15 and is discharged from the discharge port 16 into the mold, the jet flow is along the outer penetration portion 15b that expands toward the discharge port 16. As shown schematically by the arrow in FIG. 4, the flow velocity of the jet flow discharged from the discharge port 16 is decelerated and made uniform. Therefore, it is possible to suppress the occurrence of stagnation at the edge of the open end surface of the discharge port 16, stabilize the flow state of the molten steel in the mold, and prevent the mold powder from being entrained in the molten steel.

なお、上記実施例では２個の吐出口１６を、溶鋼流路１３を挟んで対向するように形成しているが、本発明は吐出口１６を３個以上形成する浸漬ノズルに適用することもできる。 In the above embodiment, the two discharge ports 16 are formed so as to face each other with the molten steel flow path 13 interposed therebetween, but the present invention can also be applied to a dipping nozzle in which three or more discharge ports 16 are formed. can.

１０…浸漬ノズル
１１…接続口
１２…底部
１３…溶鋼流路
１４…周壁
１５…貫通穴
１５ａ…内側貫通部
１５ｂ…外側貫通部
１６…吐出口 10 ... Immersion nozzle 11 ... Connection port 12 ... Bottom 13 ... Molten steel flow path 14 ... Peripheral wall 15 ... Through hole 15a ... Inner penetration part 15b ... Outer penetration part 16 ... Discharge port

Claims

It has a bottomed cylindrical structure with a connection port with a tundish at one end, a bottom at the other end, and a molten steel flow path from the connection port to the bottom at the center. An immersion nozzle with a discharge port formed on the peripheral wall in the vicinity.
Each through hole is composed of an inner penetrating portion formed on the molten steel flow path side and an outer penetrating portion formed on the discharge port side and communicating with the inner penetrating portion.
A dipping nozzle characterized in that the outer penetrating portion is expanded so that the inner diameter thereof gradually increases from the communicating portion with the inner penetrating portion toward the discharge port.