KR20030003731A - Device for continuously casting metal, particularly steel - Google Patents

Abstract

The invention relates to a continuous casting device of metal, in particular steel, having a mold wall (1, 18) and a mold with a mold cooling device. One or more mold walls (1, 18) of the mold of the continuous casting device, in order to improve such a continuous casting device to be able to use it at high casting speeds by being able to dissipate heat with high heat flow and to withstand high thermal loads. Comprises a steel mold wall (2) and a support net (3) for the steel mold wall, and acts on the steel mold wall (2) via the support net (3) to support the steel mold wall (2) A magnetic field generator 3.2 for generating a magnetic field 3.1 drawn to the side is provided, and the mold cooling device comprises an injection cooling device 10.

Description

Continuous casting machines for metals, especially steels {DEVICE FOR CONTINUOUSLY CASTING METAL, PARTICULARLY STEEL}

Such a mold as a casting mold for billet casting equipment consists of a mold plate, in particular two plates for the wide side of the mold and two plates for the narrow side of the mold, or a mold tube.

Such mold plates or mold tubes are composed of copper and usually carry a thickness of 10 to 50 mm between the water cooling section and the side opposite to the steel melt side.

The choice of copper plate thickness depends on the thermal load or the thermal flow, eg measured in units of MWh / m 2 or MW / m 2. That is, a continuous casting plant with slab-shaped molds that are over 150 mm thick and up to 3 m wide and moved at a casting speed of up to about 2.5 m / min exhibits a heat flow of up to 2 MW / m 2. The thickness of the mold plates of such molds is 25 to 50 mm. On the other hand, thin slabs that are moved at a casting speed of up to 10 m / min and up to 15 m / min in the future exhibit a heat flow of up to 4 to 5 MW / m 2 and a copper plate of about 10 to 25 mm. It becomes thickness.

In order to moderate the heat flow that increases with increasing casting speed, the copper walls must be thinner in enhancing water cooling. It is difficult because the thinner the mold wall, the more difficult it is to withstand the high water pressure of 5 to 15 bar without deformation, taking into account the corresponding water speed of 5 to 15 m / s. In addition, an excessively thin copper plate has a disadvantage in that strength is lost due to exceeding the recrystallization temperature when the heat load of the cold rolled copper is very high. In addition, problems arise when assembling very thin mold copper plates on a mold frame. Typically, the mold plate is assembled on a water box or mold frame using bolts that are screwed to the copper plate by screws on the back side. It is not possible with very thin plates, in which case the bolts must be welded onto the copper plates.

The present invention relates to a continuous casting device of metal, in particular steel, having a mold with a mold wall and a mold cooling device. Such devices are used to cast various billet shapes such as, for example, slabs, thin slabs, blooms, or beam blanks (beam preliminary sections). In that case, the mold itself or the billet (such as horizontal continuous casting) may be vibrated. However, since the mold itself is disposed in one place, it may be referred to as a stand mold.

1A shows a mold wall of a rectangular billet casting mold viewed from the steel melt side, here a side view of its wide side;

1B is a cross-sectional view of the mold wall of FIG. 1A;

2A is a cross-sectional view of a mold wall with an injection cooling device adapted to the energy flow distribution along the mold height;

2b is a chart showing the heat flow trend according to the mold height;

3A is a cross sectional view of a mold with a narrow side wall and a narrow side head for width adjustment and taper adjustment;

3b shows a ball bearing provided at the head side end of the support wall for supporting the steel mold wall to the support network.

(Explanation of drawing)

Wide side of the mold 2. River mold wall

2.1 Steel mold walls made of steel / copper, copper / steel / copper and metal / steel / metal

3. Support network 3.1 magnetic field

3.1.1 Electromagnetic brakes to calm the flow of the river in the mold

3.2 Magnetic field generator 3.3 Seals, eg rubber packing

3.4 Permanent Magnet 4 Vertical Centerline on Wide Side

4.1 Fixtures for steel mold walls5 Horizontal direction

6 Upper edge of the mold 7 Lower edge of the mold

8 vertical 9 chamber of support net (3)

10 Atomizing chiller 10.1 Atomizing nozzle

10.2 Backwash jet 11 Support wall of support net (3)

11.1 Head of support wall 11.1.1 Support wall head of graphite

11.2 Ball acts as a bearing for free movement

11.3 Fluid such as water or gas forming a fluid bearing or hydraulic bearing

12 Chamber of spray cooling apparatus 10, enclosed space

12.1 Outlet 13 Open atmosphere of the jet cooling unit (10)

14 Energy peak 15 Mold wall temperature

16 mold height 17 mold width

18 narrow side 18.1 recesses and / or internal projections

19 narrow side head 20 width adjustment

21 Taper Adjustment

22 Conventional narrow side running water cooling system with water pressure up to 20 bar

22.1 Water Resistant 23 Billet Shell

23.1 Molten steel 23.2 Immersion inlet gutter

24 casting slag24.1 flux powder

25 Casting speed26 Honeycomb form of support net (3)

It is an object of the present invention to improve the type of device presupposed that the above mentioned disadvantage no longer occurs despite the increased casting speed. In particular, a continuous casting apparatus having a mold capable of dissipating heat with high heat flow and withstanding high heat loads should be provided. Assembly must also be improved.

Such an object is achieved by an apparatus involving the features of claim 1. Advantageous additional improvements are disclosed in the dependent claims.

According to the present invention, at least one mold wall comprises a steel mold wall and a support mesh for the steel mold wall, and generates a magnetic field that acts on the steel mold wall via the support mesh and pulls the steel mold wall towards the support mesh. A magnetic field generator is provided and measures are taken to ensure that the mold chiller comprises a spray chiller.

Such features result in a mold having a mold wall that exhibits high and controlled heat release properties even at high casting speeds. Such a mold wall consists of a steel mold wall on one side towards the metal melt and a support net on the other to stabilize the steel mold wall. The steel mold wall can be simply assembled based on magnetic attraction. In addition, such molds require expensive processing by discarding the use of steel mold walls worn by steel melt, unlike costly copper plates, that is, feeding them into the steel regeneration process, as needed. It has the special advantage that it can be replaced without any complexity. The dual wall consisting of a thin steel mold wall and a support net as proposed according to the invention makes it possible to use a simple and inexpensive mold spray cooling apparatus. In order to avoid having to create high cooling water pressures, for example up to 15 or 20 bar, the spray cooling device operates in an open chamber or passageway left by the support net. That is, the thin mold wall cools directly, but nevertheless receives a relatively high support action. It is possible to use spray water for spray cooling. Overall, a simple mold structure is obtained with high efficiency associated with heat dissipation, which results in a relatively inexpensive mold. The solution according to the invention shows a thermal conduction that would otherwise have required a copper plate thickness of at least about 10 mm and can be simply assembled on the base frame, allowing for cooling of the mold on the water side while at the same time low cost mold To provide.

The steel mold wall proposed in accordance with the invention preferably has a thickness of 0.5 to 5 mm corresponding to a copper plate having a thickness of 10 mm in its action, but nevertheless exhibits structural and cost advantages.

The support net preferably has a support wall provided with a chamber therein. That is, individual chambers or passageways of the support net are surrounded by wall bridges of the support walls, with the magnetic field introduced into the mold walls via the support walls.

The spray cooling apparatus for cooling the mold wall preferably comprises a spray nozzle for cooling the back side of the steel mold wall in the chamber of the support network, ie through a chamber or gap of the support network which can be freely entered. Such spray nozzles of the mold spray cooling apparatus and in particular the supply of cooling medium, which is water, are fully or partially integrated into the support wall of the support net. Overall, the support net or support wall is formed thicker than the steel mold wall.

The spray cooling apparatus proposed according to the invention entails the advantage that the strength of the spray cooling can be set depending on the energy trend of the mold wall with the mold height. Such energy trends show a thermal maximum in approximately the upper third of the mold. The intensity of the cooling can be controlled and set by spray cooling using separate spray nozzles arranged in superimposition with one another, thereby intensively cooling at the energy transition point or energy peak point showing the energy maximum, or the energy trend or energy. The intensity of cooling can be adjusted to the peak.

In a further configuration of the device according to the invention, a device is provided for controlling the surface temperature of the side of the steel mold wall towards the liquid metal side and, if necessary, the control mechanism is adapted to adjust the spray cooling to the variation of the surface temperature.

In addition to fixing the steel mold wall to the support net as proposed in accordance with the invention, the mold plate may be further mechanically fixed. For this purpose, for example, a fixing device is provided for fixing the steel mold wall on the wide side at the center of the wide side along the mold height. In addition, the steel mold wall may be fixed horizontally to the mold inlet or the mold outlet. In addition to the wide side, if the narrow side is also stabilized by the support network, the narrow side may be fixed as necessary.

According to a very preferred embodiment, the support wall of the support net serves as a bearing (ball bearing) for the free movement of the steel mold wall due to heat at its end facing the steel mold wall, ie at the head side or at the head. With a ball. To form a fluid bearing, the ball is supplied with a fluid medium, such as water or gas. To this end, the support wall is provided with a pipeline extending perpendicular to the steel mold wall to supply water or gas to the ball or ball cage at the end face of the support wall.

In order to prevent the jetting water from flowing freely after being injected into the free back wall area of the steel mold wall, according to a further configuration of the invention the support net comprises an outer frame which is enclosed around the net with packing.

The spent cooling medium flows freely to the rear side, i.e. to the steel mold wall and the outer side, i.e. to the open atmosphere, or to the defined direction. In the latter case, it is preferable that a collection chamber be provided in the lower part of the mold wall in communication with the discharge channel to transfer the coolant to the treatment plant as needed. Within the collection chamber, the refluxing cooling medium is collected and discharged through the outlet through the walls of the support net, in particular here, via the wall parts of the support net which are respectively arranged below the spray nozzles.

Further details and advantages of the invention will become apparent from the following detailed description of the embodiments of the invention shown in the dependent claims and the accompanying drawings. In addition, in addition to the combination of the above-described features, it will be appreciated that the features alone or in other combinations are also essential to the invention.

FIG. 1 a shows a wide side 1 of a mold having two wide sides and two narrow sides and suitable for casting a rectangle such as slab or thin slab. The wide side of such a mold consists of a steel mold wall 2, for example 2 mm thick. The steel mold wall 2, which is part of the entire mold wall, is produced by the magnetic field generator 3.2 and by the magnetic field 3.1 acting on the steel mold wall 2 via a support net 3 having a support wall 11. It is pulled toward the support net 3. The steel mold wall 2 is preferably a coated steel mold wall 2.1 made of steel / copper or copper / steel / copper or other metal replacing copper. The magnetic field generator is preferably a permanent magnet 3.4.

The steel mold wall 2 having a thickness of 2 mm corresponds to a copper wall of about 14 mm in specific thermal conductivity. For further fixing, a device 4.1 is provided for fixing the wide side with the width 17 and the height 16 at the vertical center line 4, whereby thermal expansion is achieved in both horizontal directions (here arrows and Reference numeral " 5 "

In addition, the steel mold wall is also fixed at its upper edge 6 or lower edge 7 so that it can be uniformly thermally expanded in the vertical direction (which is given a vertical arrow and reference “8”). Such a fixing device in the embodiment shown here is a rod-like element that can be rotated about its longitudinal axis.

In order to avoid the need to create mold cooling water pressures up to 15 or 20 bar, the spray cooling apparatus 10 including spray nozzles in the chamber 9 or in the gaps or openings of the support net 3 as shown in FIG. 1B. ), The back side of the steel mold wall 2 is cooled. The heated cooling water or countercurrent jetting water 10.2 flows freely via the wall 11 or support wall brace of the support net. For that purpose, the jetting water is collected in a closed space or collection chamber 12 and discharged via an outlet 12.1 or into an open atmosphere 13 (see FIG. 3A).

The outer frame of the magnetized rectangular support net 3.1 is provided with a rubber packing 3.3 surrounding its circumference to prevent the mold cooling jet water 10 from being discharged arbitrarily.

The support wall 11 of the support web 3 has a ball 11.2 in the head section 11. 1 which serves as a conventional bearing or fluid bearing for the free movement of the steel mold wall 2 due to heat. Examples of bearing points and balls 11.2 can be seen from FIG. 1a. Instead of having a ball, the support web head 11. 1 may also consist of a rounded graphite head 11.1.1 which facilitates the lubrication process due to heat.

3B shows a detailed view of an embodiment of a ball bearing. The figure shows a part of the supporting wall 11 with a supporting wall head 11. 1 which houses a steel mold wall supporting ball 11. 2. The ball bearing cage is supplied with a fluid 11.3, such as water or gas, used to form a fluid bearing or hydrodynamic bearing via a pipeline. Also shown is a spray nozzle 10.1 acting between the support wall 11 or the bridge of the support net 3.

FIG. 2A shows a continuous casting apparatus or mold with immersion infusion trough 23.2 protruding into the mold. Reference numeral 24 denotes a casting slag, and reference numeral 24.1 denotes a flux powder. The molten steel 23.1 is cast in the mold via the immersion inlet trough 23.2, where solidification with the formation of the billet shell 23 begins at the mold wall. Casting speed v _c is indicated by reference numeral 25. The magnetic field 3.1 generated by the magnetic field generator 3.2 or 3.4 can be formed as an electromagnetic brake 3.1.1. To influence the flow of the river in the mold.

In FIG. 2A, the mold temperature at the mold side facing the molten steel is denoted by reference numeral 15. In order to measure the temperature, corresponding measuring devices and control devices are provided. In figure 2a an embodiment of a bearing arrangement with a rounded head, which is preferably made of balls 11.2 or graphite 11.1.1 integrated into the head of the supporting wall 3 can also be found. While it is preferable to use one type of bearing device, it is also within the scope of the present invention that the support wall has both types of bearing devices. In the mold shown in FIG. 2A provided with the injection cooling device, the countercurrent jetting water is not collected, but flows downwardly, in which case the countercurrent cooling water is collected under the mold, if necessary.

A preferred feature of the invention is that the spray cooling or the parameters of the individual spray nozzles can be adjusted to the respective cooling demands of the mold required. Thus, FIG. 2B shows the generated energy peak 14 according to the mold height, ie the maximum amount of heat released, in the upper third of the mold as compared to FIG. 2A. For control, the mold wall temperature 15 is measured to adjust the spray cooling accordingly.

3A shows an embodiment of a mold with a narrow side 18 viewed. In this embodiment, the wide side of the mold is formed according to the invention, while the narrow side is made of steel but does not have a support net. However, it is also within the scope of the present invention that the narrow side as well as the narrow side of the mold are formed according to the present invention, or only the narrow side is formed according to the present invention. In the embodiment shown, the narrow side 18 is made of steel. The narrow side 18 obtains high stability by the slightly concave portion and / or the internal convex 18.1. The narrow side 18 is assembled on its narrow narrow side head 19, which is capable of width adjustment 20 and taper adjustment 21. Such a type of structure permits water pressures of up to 20 bar in the region of the narrow side mold water cooling apparatus formed as conventionally indicated by reference numeral 22. According to another embodiment, the narrow side of the mold may be made of water-cooled copper plates corresponding to the prior art. Parts already described in the other figures are also indicated by the same reference numerals in FIG. 3A.

Returning to the wall structure as proposed in accordance with the present invention of the continuous casting mold with the cooling device, the chamber 9 and the opening of the support net 3 can take any shape and become rectangular. It is preferred that the chamber take a honeycomb shape, in which case the chamber 9 or 12 extends between the supporting walls 1.

Overall, continuous casting molds are provided that allow high controlled heat conduction and allow simple assembly, in particular simple assembly of steel mold walls. The control of the steel mold temperature can be performed not only in the casting direction (vertical direction) but also in the direction crossing the casting direction (horizontal direction). Steel mold walls can be used as a type of scrap steel sheet that does not require expensive and expensive repair treatments when worn. Relatively simple mold injection cooling can be applied which can be adjusted depending on the energy peak according to the mold height in its action or strength. Conventional jetting water can be used and the mold is of simple construction with relatively low cost.

Claims (21)

In a continuous casting device of metal, in particular steel, having a mold wall (1, 18) and a mold with a mold cooling device, The at least one mold wall 1, 18 comprises a steel mold wall 2 and a support net 3 for the steel mold wall, and acts on the steel mold wall 2 via the support net 3 to act on the steel mold wall 2. A magnetic field generator (3.2) for generating a magnetic field (3.1) for pulling (2) towards the support net (3), wherein the mold cooling device comprises a spray cooling device (10). 2. Continuous casting apparatus according to claim 1, characterized in that the steel mold walls (2) are 0.5 to 5 mm thick. The steel mold wall (2.1) according to any one of the preceding claims, wherein the steel mold wall (2.1) consists of a metal layer with at least one steel layer, preferably a steel / copper or a metal / steel / metal layer, wherein the metal is for example Continuous casting apparatus, characterized in that the copper. 4. The support network (3) according to any one of the preceding claims, wherein the support network (3) comprises a support wall (11) provided with a chamber (9) therein, and the magnetic field (3.1) via the support wall (11). ) Is introduced into the steel mold wall (2). 5. The spray nozzle (10.1) according to any one of the preceding claims, wherein the spray cooling device (10) cools the back side of the steel mold wall (2) in the chamber (9) of the support net (3). Continuous casting apparatus comprising a. 6. Continuous casting apparatus according to any one of the preceding claims, characterized in that the cooling strength of the spray cooling apparatus (10) can be adjusted depending on the energy trend in the mold wall according to the mold height. 7. Continuous casting apparatus according to any one of the preceding claims, characterized in that it comprises a device for controlling the surface temperature (15) of the side of the steel mold wall (2) facing the liquid metal. The mold wall (1) according to any one of the preceding claims, wherein the mold wall (1) comprising a steel mold wall (2) and a support net (3) for the steel mold wall has a rectangular, in particular slab or thin slab form. One or two wide sides 1 of the casting mold, each steel mold wall 2 of the wide side 1 being fixed by means of a fixing device 4.1 at the center of the wide side according to the mold height 16. Continuous casting device, characterized in that. 9. The mold according to claim 1, wherein the mold has a mold inlet 6 and a mold outlet 7, and the steel mold wall 2 is connected to the mold inlet 6 or the mold outlet 7. Continuous casting device, characterized in that fixed horizontally. 10. The free movement of the steel mold wall 2 according to claim 1, wherein the support wall 11 of the support net 3 is caused by heat at its end facing the steel mold wall 2. Continuous casting device, characterized in that it has a ball (11.2) that serves as a bearing for the. 11. Continuous casting apparatus according to claim 10, characterized in that the ball (11.2) of the ball bearing can be operated by a fluid medium. 12. The graphite support mesh head (11.1) according to any one of the preceding claims, wherein the support wall (11) of the support mesh (3) is preferably rounded at its end facing the steel mold wall (2). .1) continuous casting apparatus characterized by the above-mentioned. 13. The support mesh 3 according to claim 1, wherein the support mesh 3 comprises an outer frame which surrounds the support mesh 3, the outer frame of the mold spray cooling medium 10.2, in particular a countercurrent of water. Continuous casting device characterized in that it comprises a packing (3.3) to control. 14. A collection chamber (12) and an outlet (12.1) are provided for supporting and discharging the cooling medium (10.2) injected into the steel mold wall (2) in a predetermined direction, according to any one of claims 1 to 13. Cooling medium (10.2) flowed back through the wall (11) of the network is collected in the collecting chamber (12) and discharged through the outlet (12.1), or the injected cooling medium (10.2) is discharged to the open atmosphere (13). Continuous casting device, characterized in that. 15. The continuous casting apparatus according to any one of claims 1 to 14, wherein the mold wall forming the narrow side of the mold comprises a steel wall with internal convex portions (18.1) for mechanical stabilization. 15. The continuous casting apparatus according to any one of claims 1 to 14, wherein the mold walls forming the narrow side of the mold are made of copper plates. 17. A continuous casting apparatus according to claim 15 or 16, characterized in that each narrow side of steel is assembled on a narrow side head (19) which makes it possible to adjust the slab width and the taper of the narrow side. 18. The support wall (11) of the support network (3) according to any one of the claims 4 to 17, wherein the injection nozzle (10.1) and the cooling medium (11.3) of the mold injection cooling device (10), in particular the supply of water, are supported. Continuous casting device, characterized in that it is fully or partially integrated in. 19. A continuous casting apparatus according to any one of claims 4 to 18, characterized in that the chamber (9) of the support net (3) is in the shape of a honeycomb. 20. A continuous casting apparatus as claimed in any one of the preceding claims, characterized in that the magnetic field generator (3.2) is a permanent magnet (3.4). 21. The magnetic field (3.1) generated by the magnetic field generator (3.2) also acts as an electromagnetic brake (3.1.1.) For the molten metal (23.1) flowing in the mold. Continuous casting device, characterized in that.