EP3233329A1 - Distributor for continuous casting plants - Google Patents

Abstract

The invention relates to a distributor, in particular a distributor in continuous steel casting for arrangement between a steel casting ladle and a continuous casting mould having an inlet region (7) and an outlet region (8), wherein in the inlet region (7) liquid steel can be delivered in particular via a ladle shroud and in the outlet region (8) the liquid steel can be discharged from the distributor (1) in particular by means of a closing plug and an outlet opening, wherein in the region of the inlet region (7) in the distributor (1) a threshold (12) or ramp (12) is formed, which forms a region of the distributor base (6) as a pot (13) or tub (13), wherein the threshold (12) or ramp (12) has laterally at least one channel (15), which channel locally reduces the height of the threshold (12) or ramp (12) or interrupts the threshold (12).

Description

 Distributor for continuous casting plants

The invention relates to a distributor for continuous casting plants according to the preamble of claim 1.

The steel continuous casting is a well known method for continu ous ^¬ casting of steel slabs.

For this purpose, steel is usually produced in a converter, transferred from the steel converter in a pan and forwarded by the pan via a distributor to the casting mold.

The distributor has the task here, after emptying a pan and feeding the next pan, to ensure a continuous flow of steel.

In principle, it must be ensured that no inclusions are present in the liquid steel, in particular no slag particles or constituents of the respective refractory lining or ejection of the vessels.

This is achieved in particular by the arrangement of corresponding internals in a distributor trough, which produces a certain upward flow after filling the steel in such a way that the steel is flushed to the surface, so that particles which are lighter than the steel pass into the slag or be bound by the slag.

From DE 33 37 739 AI a continuous casting is known. This continuous casting plant has a ladle holding and changing device (ladle turret), ladles and a distributor trough and a continuous casting mold and a Strangab ^¬ zugsvorrichtung. The in preparation for transport in the pouring position filled with melt ladle is associated with a distributing trough for common transport with the ^¬ ser. Preferably, in this embodiment, the distributor trough is inserted into the jib for the reception of the ladle vorgese ^¬ Henen boom on the ladle tower below the ladle. Tundish and / or ladle are provided with ^¬ With stuffs for releasable connection with each other.

From EP 0119853 A2 a tundish for continu ^¬ ous continuous casting is known, wherein the distributor channel has a channeled induction heating device which is arranged on the side wall of the tundish, the device comprising a channel with an opening in the side walls Distributor channel communicates.

EP 0 140 217 A1 discloses a method and a device for changing the ladle and intermediate container at a continuous casting plant.

From EP 0 726 115 A1 a tundish for receiving and filtering ferrous metal melts is known, which has a discharge opening for withdrawing the molten metal after passing through a deflection and / or filter device in the bottom region, wherein in the tundish a substantially ge ^¬ velvet horizontal cross section of the tundish covering, in a known manner removable, ceramic filter is arranged, which extends substantially in the horizontal direction and is provided with passage openings, which are arranged in the substantially vertically extending flow direction of the molten metal through the tundish , which is to be achieved with a simple Konstrukti ^¬ on a cleaning or filtering of molten metals for high casting speeds. EP 0 804 306 B1 discloses an apparatus for controlling the flow of molten metal in a distributor trough to improve the separation of inclusions from the metal bath. For this purpose, a flow control dam is downstream ^¬ Windwärts positioned by a shock buffer, which has an upper portion which is adapted to receive a flow of molten steel, which disengages from the impact pad, and at least one secondary stream flowing in a downstream direction toward the slag cover , And in at least one ^{Neben ¬} stream, which flows in an upstream direction to the slag can divert. Ultimately, it is a built-in dam to prevent a short circuit flow.

From US 6,074,600 a modification of a distributor gutter dam to minimize turbulence is known. In particular, this is intended to reduce the formation of gas bubbles and slag ^inclusions . This especially in the first on ^¬ filling the distributor channel. For this purpose, on the one hand a kind ei ^¬ nes weir between the steel inlet of the distributor trough and the steel outlet of the distributor trough arranged, the weir extends from the bath surface to the bottom, but is spaced from the ground. In addition, a ramp is arranged between the weir and the steel outlet, while a second ramp is arranged in front of the weir.

From DE 10 2009 009 740 AI Vortex stones is to prevent swirls contained in molten steel vessels in the area of Bodenausläufe arranged in such a way that their knife edges ^¬ extend into the vortex. The Vortex stones consist of a circular segment-like flat fixing part and the brake part with the knife edge, this one-piece component can be placed practically on the bottom outlet or better placed on ei ^¬ nen hole stone and connected to this because the inner diameter corresponds to that of the bottom outlet.

From DE 22 16 797 passes for casting a mold are known in which liquid metal is poured into a run ^¬ by the liquid metal has to flow around a wall before it reaches an outlet or this passage is designed as a pot, before the metal gets into the actual casting mold.

From JP 10 21 69 09 A a tundish for continuous casting of steel is known, in which barrier walls with bottom-side openings and subsequent bottom-side walls are present in order to calm the steel.

From EP 02 35 34 0 an anode system for a plasma heating, which is usable in a tundish known.

From AT 405 914 B a tundish for continuous casting of steel is known in which an inlet side in the bottom of a recessed ^¬ ter pot is formed with a subsequent wall.

In addition, it is known to provide distribution troughs with a bottom drop from the steel inlet to the steel outlet, wherein on the ^¬ sen inclined floor, partially stepped floor, a wall or an increase is placed such that the steel inlet area forms a kind of pot, from the the filling of the pot of the wall is overflowed and then the Gesam ^¬ te distribution channel is filled. This Wall is also to ensure the task for a turbulent flow and prolong the Ver ^¬ residence time of the steel in the tundish something and in particular ^¬ sondere to achieve contact with the slag layer. The object of the invention is to provide a distributor inner geometry which is more effective and economical with a constant or improved particle separation.

The object is achieved with a distributor with the features of claim 1.

Advantageous developments are characterized in the subclaims.

Currently, the manifold geometry is formed such that in the inlet region of the distributor, ie in the region of the spout, in which the liquid steel ge ^¬ reached in the tundish, formed the geometry of the distributor plate as the side (sides ^¬ walls, front wall) and the bottom closed pot is. This pot has in particular the dimensions of 1 m wide, 1 m depth and 20 cm in height. This pot is open at the top and is also filled from above the shade tube from the pan with liquid steel. If this pot is filled, the wall or the installation or the ramp or the wall, which delimits the pot to the rest of the manifold, overflowed and filled the entire distributor.

This pot or trough-like shaped bottom geometry in the region of the inlet, which is also referred to below as a pot, primarily has the task of redirecting the pan and shadow tube induced liquid steel flow in the distribution inlet area in the direction of the bath mirror surface of the distributor.

The advantages of known geometry are that a tray ^¬ tion of the residence time of particles, and thus the Partikelab ^¬ distinguish probability is achieved in the molten steel flow in the manifold. In addition, short-circuit currents in the direction of distributor outlet, ie via the pouring tube into the mold, are avoided.

According to the invention, however, it has been found that when emptying the distributor, a considerable amount of residual steel remains in this pot, which is declared as scrap after cooling of the distributor. This is uneconomical. Accordingly, the invention is intended to reduce the amount of residual steel in the distributor, to increase the output and to maintain the particle separation behavior of the distributor to at least the existing extent. In addition, short-circuit currents are to be avoided in which the molten steel from the ladle on the ladle shroud directly, that flows manifold outlet by the shortest route, near the bottom of the distributor in Rich ^¬ processing and passes through the casting tube in the co ^¬ kille. Particles in this short-circuit flow can not be deposited in the distributor on the bath mirror surface of the distributor and get in this way with the molten steel directly into the mold, which must be avoided at all costs.

According to the invention, it has been found that under certain conditions it is possible to provide the pot geometry in the bottom area of the distributor inlet with openings in such a way that the dam, which delimits the pot to the rest of the distributor cavity, is partially perforated.

These openings, which are provided in the direction of the distributor outlet, and in particular channels which are open at the top, are formed starting from the two lateral longitudinal boundaries (longitudinal walls) of the distributor in the direction of the longitudinal axis of the distributor and extend in particular to the bottom of the pot. Preferably, these recesses are designed symmetrically to the longitudinal axis of the distributor.

As a result, lateral channels or at least one seitli ^¬ cher channel are formed. Based on the entire cross section of the distributor plate in the area of the wall or the incorporation ha ^¬ ben the side channels or the lateral duct an IMP EXP ^¬ including flow-through cross-sectional area which is between 10% and 30%, preferably between 15% and 25%, the cross-sectional area of the Pot lies.

Based on the total distributor bottom surface, the area of the wall or the installation is preferably less than 50% of the total area, more preferably less than 40%.

The channel or the channels can slightly from the respective side wall, ie, be from 0.01% to 25% of the width of the distri ^¬ lerinnenraums spaced.

The lateral arrangement of the channels, a short-circuit flow ^¬ is avoided and the particle separation in the manifold is maintained surprisingly at least to the same extent as in the Geomet ^¬ rie without lateral channels. It has even been found in experiments that the additional lateral channels for emptying the pot in the inlet area tend to bring about an improvement in the particle separation and short-circuit behavior.

Here is also particularly advantageous that a significant residual amount of steel that would otherwise be scrapped, is utilized at a time nor ^¬ busy steel mill. This allows ei ^¬ ne significant increase in the number of exploitable melting. Apart from that, the breaking-out of the distributor and the renewal of the refractory wear lining are made considerably easier.

The invention is exemplified with reference to a drawing erläu ^¬ tert. It shows:

Figure 1: highly schematic of a distributor according to the prior art in a view from above;

FIG. 2 shows the distributor according to FIG. 1 in a cross-sectional view;

Figure 3: a distributor according to the invention in a highly schematic view from above;

Figure 4: the distributor of Figure 3 in a side sectional view ..;

FIG. 5 shows the results of numerical CFD calculations (RTD curves);

FIG. 6 shows the distributor according to the invention in a highly schematic isometric, partially transparent view;

FIG. 7 shows the cross section through a channel according to the invention in the bottom of the distributor;

Figure 8: the flow profile at the inlet of steel in the

 Distributor according to the prior art;

FIG. 9 shows the flow profile when introducing steel into the distributor according to the invention. An inventive distributor 1 is an elongated, trogen-like container with two opposite Stirnwan ^¬ tions 2, 3 and two connecting the end walls side walls 4, 5 (Fig. 1 and Fig. 2).

In addition, the distributor 1 has a bottom 6, wherein an inlet region 7 and an outlet region 8 are provided along a longitudinal axis 9 of the distributor 1. The lead-in area 7 is adjacent to a einlaufseifigen end wall 2 is arranged, while the lead-out area 8 formed adjacent to an off-running side end wall 3, so that basic ^¬ additionally incoming steel, the longitudinal extension of the manifold 1 the following flow through the vessel.

The bottom 6 of the manifold 1 can deepen from a Einlaufbe ^¬ rich 7 to an outlet portion 8 obliquely, said obliquely means here that the depth becomes deeper toward ^¬ over a mirror 10th

At the bottom 6 of the distributor 1, a threshold 12 or ramp 12 is provided such that it forms a recessed pot 13 in the inlet region 7 of the distributor 1 to the interior 11 of the distri ^¬ lers 1 out. This pot 13 is particularly deepened rectangular, trough-shaped. The threshold 12 or Ram ^¬ pe 12 forms a directed to the interior 11, closed boundary of the pot 13 in the direction of the distributor outlet 8 and in particular a slight inclination, similar to a jump, have.

The distributor base 6 can thereby lower from an upper edge 12a of the threshold 12 with an elongated inclination 14 in the direction of the distributor outlet 8. Preferably, the bottom 6 in the region of the inlet region 7 and the outlet region 8 with respect to a bathroom mirror 10 is flat. With the bathroom mirror 10 Here, the maximum bath level 10 in the operation of the distributor 1 is meant. When emptying the distributor 1 the Badspie ^¬ gel drops from the maximum level of the bath 10 during operation.

According to the invention (FIGS. 3 and 4), the edge of the pot 13 or the threshold 12 or ramp 12 is formed at least along ei ^¬ ner side wall 4, 5 in the direction of the distributor outlet 8 with a channel-like opening 15 which extends from the upper edge 12a of the tie 12 or ramp 12, preferably ranging up to a level of the bottom 6 in the region of the a ^¬ running region. 7

This ensures that residual steel can drain out of the pot 13 and reach the outlet region 8.

For this purpose, it may be provided in particular that the channels 15 with their channel bottom 16 have a slight inclination down to the distributor outlet region 8.

The channels 15 are thus bounded on the one hand by its channel bottom 16, on the other hand by a side wall 4, 5 and a channel wall 17 of the threshold 12 or ramp 12.

In this case, the channels 15 may also be slightly spaced from the side walls 4, 5, so that the threshold 12 is not broken edge-side but a small piece to the longitudinal axis 9 is broken.

The channel 15 or the channels 15 have in a conventional distribution geometry, for example, a width of 70 mm to 80 mm, a height corresponding to the height of the threshold 12, where ^¬ it has been found to be advantageous if the channels 15 limiting walls 4, 5 and 17, respectively, from the channel floor diverging wegdivergierend, for example, at an angle of 10 ° to 20 ° (Fig. 6 and Fig. 7).

In flow simulations (FIGS. 8 and 9) it has been found that in the case of the continuous filling of the distributor, in both cases, a pronounced backflow prevails compared to the prior art (FIG. 8) through the lateral channels (FIG. 9) the sloping floor or the threshold 12 or ramp 12 results and the or the introduced channels 15 does not hinder this backflow and also does not adversely affect the residence time of the particles and the particle flow in the distributor.

Rather, it could be demonstrated that the residence time is surprisingly improved despite or because of the lateral channels (FIG. 5).

The threshold 12 or ramp 12 can be arranged perpendicular to the longitudinal axis 9 of the distributor 1, it can also be rounded or curved.

The threshold 12 has a height which is less than the maximum bath level 10 in the operation of the distributor 1, so as not to negatively influence the particle flow.

The threshold 12 preferably has a height in the ratio of less than 1: 5, particularly preferably less than 1:10, in comparison to the bath level 10.

In the invention, it is advantageous that by or incorporated channels 15 Surprisingly, the Partikelab ^¬ sheath behave not deteriorated but rather is improved, and also allows for complete emptying of the cup is, which made a much more economical work ^¬ light.

List of reference numbers:

1 distributor

 2 end wall

 3 end wall

 4 side wall

 5 side wall

 6 floor

 7 inlet area

 8 outlet area

 9 longitudinal axis

 10 bathroom mirror

 11 interior

 12 threshold / ramp

 12a upper edge of the threshold / ramp 12

13 pot / tub

 14 tilt

 15 opening / channel

 16 channel bottom

 17 duct wall

Claims

claims 1. Distributor, in particular distributor in steel casting for arrangement between a steel ladle and a continuous casting mold with an inlet region (7) and an outlet region (8), wherein in the inlet region (7) liquid steel can be supplied and in the outlet region (8) of the liquid steel the distributor (1) can be discharged, wherein in the region of the inlet region (7) in the distributor (1) a threshold (12) or the ramp (12) is formed, which forms a portion of the Ver ^¬ divider bottom (6) as a pot (13 ) or trough (13) is formed, wherein the threshold (12) or ramp (12) laterally each have a channel (15) which reduces the height of the threshold (12) or ramp (12) locally or the threshold (12) ^¬ breaks, wherein the threshold (12) has a height which is ge ^¬ ringer than the height of the distributor base (6) to the maximum bath level (10) of the manifold (1) in operation. 2. Distributor according to claim 1, characterized in that each one channel (15) reduces the height of the threshold (12) or the Ram ^¬ pe (12) completely to the level of the bottom (6) in the one ^¬ run area (7) , 3. Distributor according to one of claims 1 or 2, characterized in that the channel (15) has a slope which corresponds to the course of the bottom (6) without a threshold (12). 4. Distributor according to one of the preceding claims, characterized in that the threshold (12) has a height in Ver ^¬ ratio to the bath level (10) of less than 1: 5, more preferably less than 1:10. 5. Distributor according to one of the preceding claims, characterized in that the channel bottom (16) of the channel (15) has an inclination of 2 ° to 6 ° from the inlet region (7) to the outlet region (8). 6. Distributor according to one of the preceding claims, characterized in that in the inlet region (7) of the distributor (1) liquid steel can be fed via a shadow tube, wherein the liquid steel from the distributor (1) by ei ^¬ nes sealing plug and an outlet opening can be discharged is. 7. Distributor according to one of the preceding claims, characterized in that the channels (15) have a width which does not exceed a total of 30%, preferably 20%, of the width of the distri ^¬ lerinnenraums (11). 8. Distributor according to one of the preceding claims, characterized in that the channel (15) or the channels (15) of a respective side wall (4, 5) and one of the threshold (12) or ramp (12) formed Kanalseitenwandung ( 17) and the channel bottom (16) are limited. 9. Distributor according to one of claims 1 to 6, characterized in that the channel (15) or the channels (15) of the respective side wall (4, 5) low, d. H. 0.01% to 25% of the width of the distributor interior, is or are. 10. Distributor according to one of the preceding claims, characterized in that the channels (15) limiting Wan ^¬ applications (4, 5, 17) each widen the channel (15) from its channel bottom (16) ago, in particular at an angle of 2.5 ° to 25 °, preferably 10 ° to 20 °. Distributor according to one of the preceding claims, characterized in that the surface of the threshold (12) or Ram ^¬ pe (12) less than 50% of the total area of the ^{Verteilerbo ¬} dens (6), preferably less than 40% of the total area of the distributor base ( 6).