EP3332890B1 - Two material block nozzle with an optimized external geometry - Google Patents

Description

Field of engineering

The present invention relates to the technical field of continuous casting. In continuous casting, liquid metal, preferably steel, is poured into a mold, where a partially solidified or solidified strand is formed. The strand is continuously drawn out of the mold and supported in the mold following the mold guide, guided and further cooled. For cooling the strand in the strand guide (the so-called. Secondary cooling zone) block nozzles are often used as spray nozzles through which at least one cooling medium - in the present case, however, a liquid and a gaseous cooling medium - are applied to the strand.

• einen im wesentlichen quaderförmigen Grundkörper, der eine Grundfläche, eine Stirnfläche und mehrere Seitenflächen,
• einen ersten Anschluss für ein flüssiges Kühlmedium,
• einen zweiten Anschluss für ein gasförmiges Kühlmedium, und
• einen dritten Anschluss zur lösbaren Befestigung einer Spritzdüse an dem Grundkörper,
  umfasst.

Specifically, the invention relates to a two-component block nozzle for cooling a strand, preferably with billet or billet cross-section, in a continuous casting machine, comprising

• a substantially cuboidal basic body having a base surface, an end face and a plurality of side surfaces,
• a first connection for a liquid cooling medium,
• a second connection for a gaseous cooling medium, and
• a third connection for the detachable attachment of a spray nozzle to the base body,
  includes.

State of the art From the brochure

Spray Nozzles for Secondary Cooling in Continuous Casting Machines, Fa. Lechler GmbH, Edition 04/04 are generic block nozzles known, see, for example, the product numbers 138.XXX and 148.XXX. Although these two-component block nozzles are easy to produce, a large amount of scale accumulates on the flat surfaces of the block nozzles during operation in a continuous casting machine. Since the casting speed in modern continuous casting often already over 4, 5 or 6 m / min, the distances between immediately consecutive strand guide rollers must be kept low even in billet or blooming machines, which has a negative effect on the removal of scale from the secondary cooling zone. Thus, in operation, a large amount of scale builds up, which can lead to a blockage of the rotation of the strand guide rollers and impairs the reliability of the continuous casting machine. Thus, there is a need to improve the design of the two-component block nozzles so that less scale can settle on the outer surfaces of the block nozzles. How to fix this problem is not apparent from the publication.

From the SU 963692 A1 is a two-fluid nozzle for cooling a strand in a continuous casting known. The nozzle has a first and a second connection for a liquid and a gaseous coolant and a mixing chamber. After the mixing chamber, the coolant is discharged through a slot in the main body of the nozzle.

Summary of the invention

The object of the invention is to overcome the disadvantages of the prior art and to provide a two-component block nozzle of the type mentioned for cooling a strand in a continuous casting machine, so that during operation in a continuous casting machine less scale on the outer surfaces of the block nozzle can settle ,

This object is achieved by the two-component block nozzle according to claim 1. Advantageous embodiments are the subject of the dependent claims.

• einen im wesentlichen quaderförmigen Grundkörper, der
  • eine Grundfläche,
  • eine Stirnfläche,
  • mehrere Seitenflächen,
  • einen ersten Anschluss für ein flüssiges Kühlmedium,
  • einen zweiten Anschluss für ein gasförmiges Kühlmedium, wobei der erste und der zweite Anschluss auf der Grundfläche angeordnet sind,
  • eine Mischkammer zur innigen Durchmischung des flüssigen Kühlmediums mit dem gasförmigen Kühlmedium, wobei die Mischkammer über einen ersten Kanal mit dem ersten Anschluss und einen zweiten Kanal mit dem zweiten Anschluss verbunden ist, und
  • einen dritten Anschluss zur lösbaren Befestigung einer Spritzdüse an dem Grundkörper, wobei der dritte Anschluss über einen dritten Kanal mit der Mischkammer verbunden ist, umfasst, sowie
• zumindest eine Nut oder eine Bohrung zur Aufnahme eines Befestigungsmittels zur lösbaren Befestigung des Grundkörpers an einem Flansch auf.

The two-component block nozzle according to the invention is particularly suitable for cooling a strand with billet or billet cross section and has

• a substantially cuboid base body, the
  • a base area,
  • a face,
  • several side surfaces,
  • a first connection for a liquid cooling medium,
  • a second connection for a gaseous cooling medium, wherein the first and the second connection are arranged on the base surface,
  • a mixing chamber for intimately mixing the liquid cooling medium with the gaseous cooling medium, wherein the mixing chamber is connected via a first channel to the first port and a second channel to the second port, and
  • a third connection for detachable attachment of a spray nozzle to the base body, the third connection being connected to the mixing chamber via a third channel, and
• at least one groove or bore for receiving a fastener for releasably securing the body to a flange.

Characteristic of the two-component block nozzle according to the invention is that the size of the surfaces of at least two surfaces, preferably of at least three surfaces, from the group of the end surface and the side surfaces, by a rounding or a chamfering of each edge between the end face and a side surface, be reduced by at least 10% compared to the initial cuboidal state of the body, whereby the storage areas for scale on the surfaces are also reduced.

By this retrospectively considered simple measure the storage areas for scale on the block nozzle are significantly reduced, which has a positive effect on the reliability of a continuous casting machine with the two-component block nozzles according to the invention. Despite these significant advantages should not be concealed that the manufacturing cost of a two-component block nozzle according to the invention are substantially increased by the additional rounding or chamfering. It is particularly preferred if not only two or three surfaces are reduced by a rounding or a chamfering of an edge, but all 5 surfaces (ie, the front and the four side surfaces) of the cuboid base body. As a result, the scale deposit can be significantly reduced at any orientation of the block nozzle.

In terms of manufacturing costs, it is expedient that the base body is made in one piece and preferably has a substantially rectangular base. The main body is usually made of stainless steel or a brass or bronze alloy and is typically machined by milling.

It is expedient if the first and / or the second connection with respect to the flange by a respective seal -. an O-ring - is sealed.

The flow conditions in the channels can be set exactly, regardless of the cross sections of the ports, if a nozzle insert is arranged in the first channel and / or in the second channel.

Although the production costs increase due to large radii or chamfers, it is advantageous if the rounding or chamfering of an edge increases the size of a surface, preferably from both surfaces, by at least 20%, preferably by at least 40%, particularly preferably by at least 60%. , reduced.

In terms of production, it is favorable if at least a portion of the first channel or of the second channel is produced by a bore which is placed on a side surface, the end of the bore subsequently being blocked by a plug.

For the assembly and disassembly of the two-component block nozzle in the continuous casting machine, it is favorable if the two-component block nozzle has at least one fastening means, so that the base body can be clamped to the flange via the fastening means arranged in the groove or bore. It is particularly favorable if the fastening means is a screw which has a screw head at one end and a nut at the other end. This will prevent the screw or nut from being lost during assembly / disassembly.

It is expedient if the liquid cooling medium is cooling water and the gaseous cooling medium is air.

Particularly in the case of two-component block nozzles for billet or billet continuous casting machines, it is advantageous if the third connection is arranged on the end face, the end face has a projection and the third connection is arranged on the projection.

A convenient attachment of the fuel nozzle results when the spray nozzle has a nozzle mouthpiece and a union nut. In order to be able to orient the opening of the nozzle mouthpiece in the radial direction, it is favorable for the nozzle mouthpiece to be connected to the neck with a non-rotationally symmetrical opening via a form-fitting connection (for example a dovetail groove). The nozzle orifice may e.g. a slot-shaped (for a flat jet nozzle) or a substantially round opening (for a full or cone jet nozzle) have.

A single cooling unit has a water line, an air line and a flange plate, wherein the water line to the first terminal and the air line to the second terminal are fluid-tight manner, and a two-component block nozzle according to the invention is braced at least one fastening means with the flange plate.

In a strand with billet or billet cross-section, it is convenient to arrange four cooling units around the strand, with a respective cooling unit being assigned for cooling an outside of the strand.

Brief description of the drawings

• Fig 1 eine Darstellung in drei Rissen einer nicht erfindungsgemäßen Zweistoff-Blockdüse
• Fig 2 eine Darstellung in drei Rissen einer erfindungsgemäßen Zweistoff-Blockdüse, bei der vier Kanten zwischen der Stirn- und den Seitenflächen abgerundet sind
• Fig 3 eine Darstellung in drei Rissen einer erfindungsgemäßen Zweistoff-Blockdüse, bei der vier Kanten zwischen der Stirn- und den Seitenflächen abgefast sind
• Fig 4 eine Darstellung einer alternativen Ausführungsform zu Fig 2, bei der die Kanten zwischen der Stirn- und den Seitenflächen soweit abgerundet sind, dass der Grundkörper keine ebenen Seitenflächen mehr aufweist
• Fig 5 eine Ansicht einer Strangführung für eine Stranggießmaschine für Knüppel- oder Vorblockformate
• Fig 6 ein Schnitt quer zur Auszugsrichtung R von Fig 5

Further advantages and features of the present invention will become apparent from the following description of non-limiting embodiments, wherein the following figures show:

• Fig. 1 a representation in three cracks of a non-inventive two-component block nozzle
• Fig. 2 a representation in three cracks of a two-component block nozzle according to the invention, in which four edges between the front and the side surfaces are rounded
• Fig. 3 a representation in three cracks of a two-component block nozzle according to the invention, in which four edges between the front and the side surfaces are chamfered
• Fig. 4 an illustration of an alternative embodiment to Fig. 2 , in which the edges between the front and the side surfaces are rounded so far that the body no longer has flat side surfaces
• Fig. 5 a view of a strand guide for a continuous casting machine for billets or billet formats
• Fig. 6 a section transverse to the extension direction R of Fig. 5

Description of the embodiments

The Fig. 1 shows a non-inventive two-component block nozzle with a cuboid base body 1, for example made of stainless steel or a brass or bronze alloy is made. The base body 1 with a base 2, an end face 3 and four side surfaces 4 is machined by milling or drilling. The base 14 facing the flange 14 has a first connection 5 for the liquid cooling medium 31 cooling water and a second connection 6 for the gaseous cooling medium 32 air. The two cooling media 31, 32 are from a water pipe 33 and an air line 34, which are designed as rectangular profile tubes, through holes in the flange 14 to the terminals 5, 6 fed. The connections 5, 6 are sealed fluid-tight by seals. The cooling media 31, 32 flow in the interior of the main body 1 via a first and a second channel to a mixing chamber 7, where they are intimately mixed together. The horizontal portion of the channel from the first port 5 to the mixing chamber is created by a bore 20 resting on the side surface 4. Subsequently, the channel is closed by a plug 21. To adjust the flow conditions in the first and second channel nozzle inserts 18 may be used. In the flow direction behind the mixing chamber 7, a third channel and a third terminal 10 is arranged, wherein this sits on a projection 23. The projection 23 has an external thread, so that a spray nozzle 11 with a nozzle mouthpiece 24 and a cap nut 25 can be exchangeably fixed. The nozzle mouthpiece 24 is designed in the illustrated case as a flat jet nozzle and has an elongated opening 26, so that the spray jet leaves the nozzle with an opening angle α. The base body 1 is braced by two fastening means 13 designed as screws, which are arranged in grooves 22 in the installed state, with the flange 14 and the water 33 and the air duct 34.

The problem with this embodiment is that, depending on the spatial orientation of the two-component block nozzle, scale can settle on the end face 3 and optionally on one or more side faces 4.

This problem is solved by the subject invention according to the embodiments of FIGS. 2 to 4 solved. In the following, reference will be made only to the differences between the non-inventive embodiment Fig. 1 and the embodiment according to the invention.

In the embodiment according to FIG. 2 four edges between the end face 3 and the side surfaces 4 of the substantially cuboid base body 1 are rounded. This reduces the surface area of the end face 3 by 48% and the surface area of the side faces 4 by 25% (wide side) or by 20% (narrow side).

In the embodiment according to FIG. 3 four edges between the end face 3 and the side surfaces 4 of the substantially cuboid base body 1 are chamfered. Also thereby reduces the surface area of the end face 3 by 48% and the surface area of the side surfaces 4 by 25% and 20%.

The Fig. 4 finally shows an alternative to the embodiment according to Fig. 2 , In this case, the originally cuboid basic body 1 is rounded by an elliptical rounding of the edges respectively between the end face 3 and an original side surface so far that the base body no longer has planar side surfaces. The face is thereby reduced by more than 50%.

The Fig. 5 shows a section of a strand guide for a strand 30 with billet or billet format with multiple strand guide rollers 28 and multiple inventive two-component block nozzles with spray nozzles 11. Here, the coming of the mold in the extension direction R strand 30 is supported on all four sides by strand guide rollers 28 led and further cooled by the two-component block nozzles.

The Fig. 6 shows the arrangement of four strand guide rollers 28 to support the strand 30, wherein in each case a two-substance block nozzle an outer side of the strand 30 is assigned. Each fuel nozzle 11 of a two-substance block nozzles brings a spray cone 27 for cooling an outer side of the strand 30.

LIST OF REFERENCE NUMBERS

1

body

2

footprint

3

face

4

side surface

5

first connection

6

second connection

7

mixing chamber

10

third connection

11

nozzle

13

fastener

14

flange

15

rounding off

16

chamfer

17

poetry

18

nozzle insert

20

drilling

21

Plug

22

groove

23

approach

24

Nozzle mouthpiece

25

Nut

26

opening

27

spray cone

28

Strand guide roller

30

strand

31

liquid cooling medium

32

gaseous cooling medium

33

water pipe

34

air line

α

spray angle

R

Extraction direction of the strand

Claims (14)

1. Dual-material block nozzle for cooling a strand (30), preferably having a billet or pre-block cross section, in a continuous casting machine, having

   - substantially cuboid base body (1), wherein the base body (1) comprises

   - a base face (2);

   - an end face (3);

   - a plurality of lateral faces (4);

   - a first connector (5) for a liquid cooling medium (31) ;

   - a second connector (6) for a gaseous cooling medium (32), wherein the first and the second connector (5, 6) are disposed on the base face (2);

   - a mixing chamber (7) for thoroughly mixing the liquid cooling medium (31) with the gaseous cooling medium (32), wherein the mixing chamber (7) by way of a first duct is connected to the first connector (5), and by way of a second duct is connected to the second connector (6); and

   - a third connector (10) for releasably fastening a spray nozzle (11) to the base body (2), wherein the third connector (10) by way of a third duct is connected to the mixing chamber (7); as well as

   - at least one groove (22) or a bore for receiving a fastening means (13) for releasably fastening the base body (1) to a flange (14);
   wherein the size of the surfaces of at least two faces, preferably of at least three faces, from the group of the end face (3) and the flat lateral faces (4) in relation to the cuboid initial state of the base body (1) are reduced by at least 10% by a rounding (15) or a chamfer (16) of in each case one edge between the end face (3) and a lateral face (4), on account of which the bearing faces for scale on the surfaces are likewise reduced.
2. Dual-material block nozzle according to Claim 1, characterized in that the base body (1) is embodied so as to be integral and preferably has a substantially rectangular base face (2).
3. Dual-material block nozzle according to one of the preceding claims, characterized in that the first and/or the second connector (5, 6) in relation to the flange (14) are/is in each case sealed by one seal (17).
4. Dual-material block nozzle according to one of the preceding claims, characterized in that a nozzle insert (18) is disposed in the first duct and/or in the second duct.
5. Dual-material block nozzle according to one of the preceding claims, characterized in that the rounding (15) or the chamfer (16) of an edge reduces the size of a surface by at least 20%, preferably by at least 40%, particularly preferably by at least 60%.
6. Dual-material block nozzle according to one of the preceding claims, characterized in that at least one portion of the first duct or of the second duct is produced by a bore (20) placed onto a lateral face (4), wherein the end of the bore (20) is subsequently plugged by a plug (21).
7. Dual-material block nozzle according to one of the preceding claims, characterized in that the dual-material block nozzle has at least one fastening means (13) such that the base body (1), by way of the fastening means (13) disposed in the groove, can be braced in relation to the flange (14).
8. Dual-material block nozzle according to one of the preceding claims, characterized in that the liquid cooling medium (31) is cooling water, and the gaseous cooling medium (32) is air.
9. Dual-material block nozzle according to one of the preceding claims, characterized in that the third connector (10) is disposed on the end face (3), the end face (3) has an attachment (23), and the third connector (10) is disposed on the attachment (23).
10. Dual-material block nozzle according to Claim 9, characterized in that the spray nozzle has a nozzle mouthpiece (24) and a union nut (25).
11. Dual-material block nozzle according to Claim 10, characterized in that the nozzle mouthpiece (24) by way of a rotationally non-symmetrical opening (26) is connected to the attachment (23) by way of a form-fitting connection.
12. Dual-material block nozzle according to one of Claims 10 or 11, characterized in that the nozzle mouthpiece (24) has a slot-shaped or a substantially round opening (26).
13. Cooling unit having a water line (33), an air line (34), and a flange (14), wherein the water line (33) is connected in a fluid-tight manner to the first connector (5), and the air line (34) is connected in a fluid-tight manner to the second connector (6), characterized in that a dual-material block nozzle according to one of the preceding claims in relation to the flange (14) is braced by way of at least one fastening means (13).
14. Secondary cooling for cooling a strand (30) having a billet or pre-block cross section, having four cooling units according to Claim 13, wherein one cooling unit is in each case assigned for cooling one external side of the strand (30).

Images