WO2012146220A1

WO2012146220A1 - Immersion tube having a nozzle

Info

Publication number: WO2012146220A1
Application number: PCT/DE2011/001798
Authority: WO
Inventors: Edgar Schumacher; Renata Franzky
Original assignee: Techcom Gmbh
Priority date: 2011-04-29
Filing date: 2011-04-29
Publication date: 2012-11-01
Also published as: EP2701867A1; DE112011105197A5

Abstract

The present invention relates to an immersion tube (1) for use in metallurgy, at the lower end of which is arranged a nozzle having two outlet channels (5, 6) for liquid metal. A jacket (4) is arranged over the end of the immersion tube (1) and takes on a guiding function for the flow of the emerging liquid metal. The base (2) of the nozzle and the walls of the bell-like jacket (4) have at least one bore, through which a compressed medium, e.g. air, is able to escape.

Description

DIVE TUBE WITH NOZZLE

The invention relates to a dip tube with a nozzle for use in the

Production of metallurgy, in particular for the production of continuous casting slabs.

This type of dip tube nozzles is known in the prior art from document EP 2 172 290 A1. This document is a diving nozzle with a bottom at the end of a dip tube to remove. About the end of

Immersion tube a bell-shaped jacket is arranged, which is open at the bottom. The liquid metal flows laterally out of the nozzle at a predetermined angle and strikes the walls of the bell-shaped shell before it emerges downwardly from the opening during the casting process into the mold and solidifies. As a disadvantage of this dew chrohrdüse it is felt that due to the high flow rate with which the liquid metal flows through the dip tube, at the lower end of the dip tube on which the nozzle is arranged, a relatively high pressure builds up, which leads to the bottom of the nozzle pops out », whereby the further casting process is interrupted and completely prevented. Furthermore, in DE 24 42 915 discloses a pouring tube with a closed bottom and opposite side openings are disclosed, which are surrounded by so-called baffles against which the liquid steel bounces when he the pouring tube leaves. Normally, the angle between the longitudinal axis of this pouring tube and the central axis of the outlet openings 90 °, whereby the structure of a laminar flow is difficult, which is disadvantageous to the outflow of the liquid metal and the type of crystallization in the

Receptacle (mold) affects

In the continuous casting of steel is one of the important tasks, the suppression of the consistency of dendrite formations in the first phase of the crystallization of the

The casting process with a dip tube with a nozzle is inefficient when B »h. This disadvantageous relationship has a negative impact on the crystallization yield and thus on the quality of the blank in the

Casting container (mold). Further disadvantages are described in more detail in the document EP 2 172 290 A1.

It is therefore an object of the present invention to provide a dip tube with a nozzle which is surrounded by a bell-shaped jacket and the

Disadvantages of the prior art largely eliminated.

This object is solved by the characterizing features of the main claim.

According to the invention, the dip tube is arranged with a nozzle arranged in the lower region with a bottom and at least one side channel over a bell-shaped shell is characterized in that the side walls of the bell-shaped shell have at least one bore and the bottom of the nozzle also has at least one bore, from where a (compressed) medium can flow out. Further advantageous embodiments can be found in the dependent claims.

It is advantageous that the cross section of the bell-shaped shell is slightly elongated and preferably depends on the shape of the molten metal receiving the mold.

Another advantage is that the bell-shaped shell has at least two opposing planar surfaces whose lengths are variable.

It is also advantageous that the angle (u) between the plane-parallel walls and the axis of the exit bores of the nozzle is substantially an acute angle, which is preferably between about 20 ° and 45 °

It is also advantageous that the two opposing plane-parallel walls are smoothly interconnected by two arc walls on the inner surfaces, the length of the plane-parallel walls is arbitrary, so that in extreme cases, the two curved walls abut each other with their sides and the

Cross-section perpendicular to the longitudinal axis through the jacket is substantially round.

It is also advantageous that the nozzle is arranged in the center of the shell.

Another advantage is seen in the fact that both the dip tube and the bell-shaped jacket on its outer sockets of a

heat-resistant layer, which is preferably a ceramic glass fiber layer, coated.

With the proposed new Taudirohrdüse the above-described disadvantages of the known dip tube nozzles are largely eliminated and represent a significant advantage in the production of steel ingots in molds in continuously cast blocks for the entire production spectrum. In the following, the invention will be explained in more detail with reference to drawings. It shows

Figure 1: a schematic QuerschnittsdarsteUung of

lower part of the dip tube {1) with a nozzle;

Figure 2: rotated by 90 ° cross-sectional view of

bottom part of the immersed raw res with {1) nozzle along the section line A-A;

Figure 3: a schematic cross-sectional view of

Immersion tube (l) along the section line B-B in Figure 1;

FIG. 4 shows two schematisehe cross-sectional views of

along the lower end of the dip tube <1)

the section line B-B.

FIG. 1 shows a schematic cross-sectional view through the lower part of the catch tube 1 with a nozzle, which has two outlet channels 5, 6 in the present exemplary embodiment. About the end of the dip tube 1 is a

g-like jacket 4 arranged. The dip tube 1, at whose lower end at least one outlet channel 5 is arranged, consists essentially of a refractory material, which withstands a temperature of up to about 1800 ° C. The lower side of the bell-shaped shell 4 is completely open, so that the liquid metal can buy freely. From this opening of the bell-shaped shell, the liquid metal enters the Aufnahmebehättnis 12 (mold) in which the crystallization of the liquid metal takes place. The liquid metal flows with a relatively high

Speed through the flow channel 3 and strikes the bottom 2 of the dip tube nozzle, so that the liquid metal finally from the two

Exit channels 5, 6 emerges. This results in the lower part of the nozzle, a relatively high pressure medium, which can not be compensated solely by the outlet channels 5, 6. For this reason, the soil 2 is at least a bore 13 from which a compressed medium can escape in the initial phase of the casting with liquid metal before the liquid metal passes through the outlet openings of the channels 5, 6. Upon discharge of the liquid metal from the outlet channels 5, 6 this flows against the jacket walls 10, 11 and is directed from there in a predetermined direction. Again, there is a similar phenomenon of the pressure build-up as in the flow channel 3 of the dip tube 1. For this reason, the shell walls 8, 9, 10, 11 at least one bore 13, 13 'on

FIG. 2 shows a schematic cross-sectional drawing along the section line A-A, rotated by 90 ° with respect to FIG. From Figure 2 shows that the dip tube bell 4 is not rotationally symmetrical to the central axis of the dip tube 1. These curved walls of the giockenähn borrow shell 4 have at least one bore 14, 14 ', through which a compressed medium can escape during pressure build-up under the jacket.

FIG. 3 shows a schematic cross-sectional view in plan view, in which the section line runs along the section line B-B in FIG. The

The cross-sectional shape of the bell-shaped shell 4 depends essentially on the shape of the receptacle 2 (mold), which receives the liquid metal. In the present embodiment, the mold is rectangular in plan view, whereby the cross-sectional shape of the gtockenähnlichen hood 4 is formed oval. In this case, the jacket 4 has two plane-parallel walls 8, 9, which are arranged on both sides of the end of the dip tube 1. On both sides of the plane-parallel walls 8, 9 close smoothly and smoothly on each side to a zyi indian Haibschaie, so that the total cross-section is substantially oval. The length of the plane - parallel walls of the

bells similar coat is variable and in extreme cases very small, so that the cross section of the shell 4 is slightly oval to round. The immersion tube 1 is arranged in the center of the g curls shaped like 4, which at the end has two Austnttskanäle 5, 6, which lie on a common axis 7, the α with the plane-parallel walls on both sides of an angle which is essentially an acute angle and is between 20 ° and 45 ° degrees. The radius R of the cylindrical half shells of the shell 4 depends essentially on the geometric dimensions of the mold 12.

FIG. 4 shows a schematic cross-section along the section line B-B in FIG. 1, in which two dip tube nozzles are arranged in a mold 12 '. The special thing about this arrangement is that the two

Exit channels 5, 6, which are located on a common axis 7, are arranged at the second dip tube V rotated by 90 ° degrees, so that the directions of the exiting flows of the flößig Metalts from two lower openings of the bell-shaped casing 4, 4 'initially a common Turn direction and thus more evenly distributed in the mold 12 '. I in this present embodiment are in the respective bell-shaped

Casing walls a total of four holes 13, 13 ', 14, 14 ^* arranged the easy escape of flows of compressed media, eg. B.

Air currents, allow.

Claims

1. dip tube (1) with a nozzle arranged in the lower area with

a floor (2) and at least one side channel (5, 6) over which a bell - shaped jacket (4) is arranged, d a d u r c h gekennzeichne that the bottom (2) of the nozzle and / or

Side walls (8, 9, 10, 11) of the bell-shaped shell have at least one bore (13, 4) from which a medium can flow.

2. dip tube according to claim! d a d u r c h characterized in that the cross-section of the bell-shaped shell (4) is slightly elongated and preferably according to the shape of the liquid metal

receiving mold (12).

3. Immersion tube according to claim 1, characterized in that at least two opposing surfaces (8, 9) on the

bell-shaped jacket (4) are flat.

4. Immersion tube according to claim 1, characterized in t that the angle (a) between the plane-parallel walls (8, 9) and the axis of the outlet bores (5, 6) of the nozzle is substantially an acute angle, preferably between about 20 ° and 45 °.

5. Immersion tube according to claim 1, characterized in that the two opposing plane-parallel walls (8, 9) are gtatt connected to each other by two arcs, wherein the length of the plane-parallel walls are arbitrarily long, so that in extreme cases, the two sheets abut each other with their sides and the cross-section perpendicular to the longitudinal axis of the dip tube (1) through the jacket is substantially round.

6. Immersion tube according to claim 1, characterized in that the nozzle is arranged in the center of the jacket.

7. dip tube according to claim 1, characterized in that the material of the bell-shaped jacket (4) is different from that of the dip tube (1).

8. dip tube according to claim 1, characterized in that the dip tube (1) at least partially and the bell-shaped shell {) outside a layer, preferably a ceramic

Fiberglass Schichf (15) is, has.

9. Immersion tube according to claim 1, characterized in that the lower end of the dip tube (1) with the nozzle in a

Aufhahmebehäitrtis (12, 12 ') (mold) is installed.