EP3695918A1 - Mould unit for continuous casting of metallic products and strand casting system - Google Patents

Abstract

The invention relates to a mold unit (8) for the continuous casting of metal products, in particular for the continuous casting of blooms, comprising a mold tube (24) with a polygonal cross-sectional shape and a mold tube (24) surrounding the mold tube (24) and forming a coolant gap (44) with the mold tube (24) In order to achieve a long service life of the mold tube (24) or an optimized internal quality of the cast metal products, it is proposed that several separate reinforcement plates (30), which are arranged outside the coolant conductive jacket (32) and which are without contact with one another, be installed on the To fasten the mold tube (24).

Description

The invention relates to a mold unit for the continuous casting of metal products, in particular for the continuous casting of blooms. The invention also relates to a continuous caster.

In the - usual - continuous casting (in continuous casting plants), liquid steel is poured from a ladle into a distributor and then vertically through a pouring pipe into a water-cooled (copper) mold.

Chill molds can have different shapes, whereby, for example, slab, bloom, billet and profile strands can be produced.

When passing through the mold, an already solid strand shell forms on the (copper) walls of the mold, while a core of the strand is still liquid. Subsequently to the mold, the strand, which continues to solidify, is drawn off by guide and drive rollers and brought into a horizontal position. The strand is cooled further with water nozzles. After complete solidification, the strand is cut into pieces of the desired length at the end of the casting plant.

In molds for continuous casting of metal products, such as blooms, a distinction is made between so-called plate molds and so-called tubular molds.

Plate molds comprise several separate mold plates which contact one another and which together form a casting mold with a polygonal, in particular rectangular, cross-sectional shape.

In contrast, tubular molds comprise a mold tube which forms a casting mold with a round, in particular circular cross-sectional shape or a polygonal, in particular rectangular, cross-sectional shape.

One advantage of a plate mold is that its mold plates can be stored in such a way that a distance between opposing mold plates can be adjusted so that metal products of different formats can be cast with the plate mold.

Another advantage of a plate mold is that the mold plates, which are still thick at the beginning of a mold travel, can be reworked again and again in order to compensate for the wear caused by the strand on the inside of the mold plates, and that damaged or worn mold plates can be reworked or replaced in a targeted manner. For post-processing, however, the plate mold has to be dismantled again and again and screwed back exactly after processing.

The mold plates that are still thick at the beginning of a mold travel naturally have poorer heat dissipation than the thinner mold plates towards the end of the mold travel. This means that there are no constant operating conditions, which is to be assessed as disadvantageous.

Another disadvantage of a plate mold is that assembling the plate mold and matching the mold plates to the exact position are complex. The joint - two - mold plates is also generally very sensitive and prone to damage and different thermal expansion.

Another disadvantage of a plate mold is that there can be gaps between adjacent mold plates at its corner regions, into which foreign bodies, such as residues of (liquefied) casting powder, penetrate can and / or liquid metal can penetrate. Here, sharp-edged ridges, so-called fins, can arise on the strand. When a strand is conveyed out of a plate mold, fins are subject to higher static friction than the rest of the surface of the bar. This creates mechanical stresses that can lead to the breaking of a strand shell that is forming.

The problem described above does not normally occur at the corner regions of a tubular mold (with a polygonal cross-sectional shape), since the side walls of the mold tube are normally formed integrally with one another.

However, only a single format of a metal product can be cast with a single-piece tubular mold. In addition, in the case of a tubular mold made in one piece, it is not possible to exchange individual side walls in a targeted manner if they are damaged or worn.

Up to now, tubular molds have mainly been used for the continuous casting of small-sized metal products, i.e. H. Casting formats below 240 mm are used. For the continuous casting of large-sized metal products, plate molds have usually been used up to now. However, in the continuous casting of large-format metal products, tubular molds have recently been increasingly used, since with a tubular mold the problem of the formation of fins usually does not occur and means reduced maintenance costs.

In the case of a tubular mold that is to be used for the continuous casting of large-format metal products, care must be taken to ensure that the wall thickness of the mold tube (usually approx. 8% to 11% of the casting format dimension) is not chosen too large, so that for the purpose of being - favorable for high-quality metal products - Heat dissipation to a coolant, a sufficiently good heat transfer through the mold tube can be guaranteed. In addition, a greater wall thickness can generate higher temperature stresses cause in the mold wall, which results in stability and service life losses.

A small wall thickness of the mold tube has the disadvantage, however, that the high (coolant) pressures acting on the mold tube can lead to deformation of the mold tube and consequently to a shortened service life of the mold tube.

In the prior art, the aforementioned disadvantage of a low wall thickness of the mold tube is compensated by the fact that several reinforcement plates surrounding the mold tube are fastened or screwed on the outside of the mold tube, which give the mold sufficiently high rigidity (support system).

From the EP 1 468 760 A1 a mold unit for continuous casting of metal products is known, which comprises a mold tube which has a plurality of corner regions. In addition, the mold unit comprises several separate reinforcement plates, which are screwed to the outside of the mold tube and together completely enclose the mold tube, with a coolant guide gap for guiding a coolant being formed between each of the reinforcement plates and the mold tube (surrounding support (system) / coolant conductive jacket).

The disadvantage of such known tubular molds with a mold tube reinforced by reinforcing plates is that thermal expansions of the mold tube and / or a cooling water pressure also have an effect on the support system and there - especially if the support system also forms the coolant conduction jacket or vice versa - to tension and / or Can lead to deformations. This can adversely affect the service life of a tubular mold.

One object of the invention is to improve the disadvantages of the prior art in tubular molds.

Another object of the invention is to enable a mold unit which has a mold tube with a polygonal cross-sectional shape and a coolant conduction jacket surrounding the mold tube and forming a coolant gap with the mold tube, or a continuous caster equipped with such a mold unit to achieve a long service life .

This object is achieved according to the invention by a mold unit according to claim 1 and by a continuous casting plant according to claim 15.

Preferred embodiments of the invention are specified in the further patent claims and in the following description.

The mold unit according to the invention for the continuous casting of metal products, in particular for the continuous casting of blooms, comprises a mold unit for the continuous casting of metal products, in particular for the continuous casting of blooms, comprising a mold tube with a polygonal cross-sectional shape and a coolant conduction jacket surrounding the mold tube and forming a coolant gap with the mold tube.

Furthermore, in the mold unit according to the invention, the multiple separate reinforcing plates are arranged outside the coolant conduction jacket and attached to one another on the mold tube without contact.

In other words, in the mold unit according to the invention, the individual, separate reinforcing plates (which are arranged outside the coolant conduction jacket and attached to the mold tube (- and thus "reinforce" or "keep in shape") the mold tube) do not touch each other , ie they are not connected to one another - and so free from one another.

As used herein, a "plate" can be seen as a flat, on two opposite sides, i.e. H. a plate top and a plate underside, each defined by a piece of, in particular hard, material bounded by an area that is extended in relation to a plate thickness.

In the present case, “contactless” or “contactless” (of the separate reinforcing plates to one another) can be understood in particular to mean that the separate reinforcing plates are not directly connected to one another in a material, form-fitting or force-fitting manner.

In the present case, the term “polygonal” is also not necessarily to be understood in a strictly mathematical or geometric sense. In the context of the invention, a “polygonal” (cross-sectional) shape, such as a rectangular (cross-sectional) shape, in particular a (cross-sectional) shape with rounded corners can be understood.

In the present case, the mold tube of the mold unit is a casting mold which has several side walls, i. H. the tubular mold side walls, or tubular mold side faces for short, which are formed integrally with one another.

The invention is based on the knowledge that during operation of the mold unit there is a thermal expansion or thermal movement of the mold tube - as well as - connected to this - the reinforcement plates - fastened to it.

When the reinforcement plates, which are intended to reinforce the mold tube or to keep it in shape, are in contact with one another or touch one another, for example when they are screwed together, the reinforcement plates are prevented from thermal expansion. This can lead to mechanical stresses, particularly in corner areas of the mold tube, which can damage the reinforcement plates and / or on the mold tube and consequently can lead to a shortened service life of the mold unit.

Since in the invention the - separate - reinforcement plates, which reinforce the mold tube or keep it in shape, are not in contact with one another or do not touch one another, ie. H. are non-contact or non-contact with one another, the separate reinforcement plates can perform thermal expansions or thermal movements relative to one another. In short, they are free to one another.

In this way, the occurrence of large mechanical stresses can be avoided, in particular at the corner areas of the mold tube. In this way, a longer service life of the mold unit and consequently a longer service life of a continuous casting plant equipped with such a mold unit can be achieved.

In other words, in the mold unit according to the invention, the separate reinforcement plates are each "laid out" in a floating position, i.e. that is, outside the coolant duct, separated from the tubular mold / mold tube or its tubular mold wall / mold tube wall or walls and arranged below / to one another without contact or contact or on the tubular mold / mold tube or on a tubular mold wall / mold tube wall or on the tubular mold / mold pipe walls / side surfaces attached.

The respective tubular mold / mold tube wall / side surface thus has "its individual support wall" - with the separate reinforcement plate fastened to it in this way - and is held or supported by this in the form.

Thus, the support system formed by the separate reinforcement plate (the respective tubular mold wall or mold tube wall) is free from interfering external forces and from thermal expansions / thermal movements of the tubular mold, in particular the usually - adjacent walls of the tubular mold adjoining the respective tubular mold wall / mold tube wall at right angles.

The thermal expansion of adjacent pipe mold walls thus has no effect on the dimensional stability of the respective pipe mold / mold pipe wall or pipe mold as a whole.

Thus, the tubular molds in the tubular mold unit can also be built for formats of any size, especially large casting formats, without constantly increasing the tubular mold / mold tube wall thickness (which would worsen the cooling). Wall thicknesses can be kept constant - "thin-walled" - at approx. 20 to 25 mm.

The mold tube is preferably a copper tube. That is to say that the mold tube is preferably made of copper or a copper alloy. This ensures that the mold tube has a high thermal conductivity. The reinforcement plates mentioned above can for example be made of stainless steel, for example of the steel grade WNr. 1.4301.

In a preferred embodiment of the invention, the mold tube has a mold cavity which, in cross section of the mold tube, has a rectangular shape, in particular a rectangular shape with rounded or pre-chamfered corners.

Furthermore, it is preferred if said rectangular shape of the mold cavity has a length of at least 280 mm, in particular at least 320 mm, and / or a width of at least 240 mm, in particular at least 280 mm. This means that large casting formats in particular are produced here.

Furthermore, the mold cavity of the mold tube can be curved. That is, the mold unit can be a so-called arched mold. Alternatively, the mold cavity can be straight.

It is also advantageous if the mold tube has a wall thickness of at most 35 mm, preferably at most 30 mm, in particular approximately 20 mm to 25 mm. On the one hand, this enables the mold tube to be manufactured more cost-effectively, since comparatively little material is required to manufacture the mold tube. On the other hand, this enables good heat transfer through the mold tube, so that a strong cooling effect can be achieved on the molten metal to be cooled with the aid of the coolant.

The wall thickness of the mold tube can be constant over the entire mold tube. Alternatively, the mold tube can have different wall thicknesses. In the latter case, the formulation that the mold tube has a wall thickness of at most 35 mm or at most 30/25/20 mm can be understood as meaning that the wall thickness of the mold tube at its / its thickest point (s) is at most 35 mm or at most 30/25/20 mm.

It can also be expedient if a mold tube wall / side surface has its own "individual" separate reinforcement plate, which - fastened there - keeps it in shape. That is, it is provided here that the mold tube has a plurality of mold tube side surfaces and each separate reinforcement plate is attached to a different mold tube side surface. If necessary, a respective separate reinforcement plate can thus be adapted to "its" respective mold tube wall / side surface.

In particular, it can further be provided here that each mold tube wall / side surface of the tube mold has its own “individual” separate reinforcement plate. In other words, the number of separate reinforcement plates corresponds to the number of mold tube walls / side surfaces, one of the separate reinforcement plates being fastened to each mold tube side surface / wall.

The mold tube can for example have a rectangular cross-sectional shape. In this case, four separate reinforcement plates are expediently attached to the mold tube, each of which is attached to a different one of the four tube mold walls. That is to say, the aforementioned several separate reinforcement plates can in particular be four “individual” separate reinforcement plates, one for each tubular mold / mold tube wall.

It is also expedient if a separate reinforcement plate, in particular all separate reinforcement plates, is or are pretensioned on the mold tube (“tension-compression” holding / fastening system).

The fastening of one or the separate reinforcement plates to the mold tube can also take place selectively, for example by means of sleeves and / or retaining screws, which point fastenings then the coolant conduction jacket, for example for the coolant “water” also called “water conduction jacket” (and the coolant gap or Water gap) enforce stilt-like, the coolant / water gap is not restricted "over a large area".

It is also expedient here if the penetrations are sealed, for example by means of O-rings or the like.

In particular, a plurality of fastening systems can be provided for fastening the separate reinforcement plates to the mold tube per se.

The number of fastening systems can expediently be selected depending on the shape and / or dimensions and / or wall thickness of the mold tube, for example from 10 to 50 fastening systems, in particular 10 to 20 fastening systems for casting formats from 350 to 420 mm or 15 to 30 fastening systems for Casting formats from 420 mm to 500 mm or 25 to 40 fastening systems for casting formats from 500 to 530 mm.

The fastening systems can be arranged symmetrically and / or in columns or rows.

Such a fastening system can provide a connecting element (for example a “fixing / retaining screw”) which has a threaded section and a threaded insert which is inserted, in particular screwed, into a recess in the mold tube.

In the present case, a threaded section of a connecting element is to be understood as a section of the connecting element provided with a thread.

The connecting element can then be screwed into the threaded insert by means of its threaded section.

The threaded inserts enable the reinforcement plates to be installed quickly and easily on the mold tube using connecting elements.

The term “inserted” is not necessarily to be understood in the present case in such a way that the respective threaded insert has to be arranged completely in a recess. In one embodiment, the respective threaded insert can protrude from the recess.

It can also be provided here that the connecting element is designed as a screw ("fixing / retaining screw") with a threadless screw shaft section, in particular with the threaded section at one end of the screw and a screw head or a head nut that can be screwed onto the screw at another End of the screw.

Such a screw can, for example, be an M12 screw according to DIN.

Fastening systems designed "slim" in this way have the particular advantage that lateral thermal expansions / movements of individual tubular mold walls / side surfaces can be compensated for.

It can also be useful if the fastening system has an adjusting screw sleeve which is screwed into a through hole in the separate reinforcing plate and which surrounds part of the connecting element, in particular the threadless screw shaft section.

The screw-on adjustment sleeve can lie on the outside of the mold tube (and / or on the threaded insert) on the front side - and the screw head or the head nut can - on the other end, on the screw-on sleeve on the front side - rest on the screw-on screw sleeve.

Preferably, the screw-on sleeve can also be clamped between the reinforcement plate and the mold tube in this way.

The adjusting screw sleeve or the adjusting screw sleeve of such fastening systems can be used for the separate reinforcement plates with a fixed axial length or e.g. can be made axially adjustable through the screw connection. The floating, separate reinforcement plates lifted from the pipe mold or pipe mold / mold pipe wall / side surface, together with the adjustable screw-on sleeve systems, offer the possibility of adapting the reinforcement plate attachment to imprecise outer surfaces of the pipe mold pipes.

There are therefore no tight tolerance requirements for the outer surfaces of the tubular mold tubes. The tubular chill tubes can thus be manufactured using the drawing process without subsequent machining of the outer surface ("unmachined tubular chill tubes").

This production is inexpensive and customary for small-format and self-supporting tubular mold tubes of this type.

This production method can also be adopted for the supported, large-format pipes thanks to the adaptability. This is also advantageous when using regenerated tubular mold pipes (revised and repaired for another trip).

Furthermore, it can also be provided that the adjusting screw sleeve is secured in the separate reinforcement plate by means of a lock nut.

If necessary, washers and the like can also be used in the fastening systems. Spring elements, such as one or more disc springs, can also be used.

According to a preferred embodiment it is provided that the mold tube, the coolant conduction jacket and the separate reinforcement plates are arranged in a coolant, in particular water tank ("wet storage").

Furthermore, a cooling water distribution flange can be provided here - especially in the case of "wet storage" - for fastening the mold unit to a mold carrier device, which has one or more coolant inlet / inlets and one or more coolant outlet / outlets, the coolant inlet (s) and the or the coolant outlets of the cooling water distribution flange is / are fluidly connected to the coolant gap.

Alternatively, "dry storage" can be provided in which the separate reinforcement plates are not in contact with the coolant, ie are independent of the mold tube cooling.

Particularly in "dry storage", the separate reinforcement plates, since the separate reinforcement plates are independent of the mold tube cooling, vary in shape and thus be designed according to a given deformation profile of the tube mold or a tube mold / mold tube wall / side surface.

A full-surface design of a separate reinforcement plate is usually favorable. The shape can, however, also have openings and / or be clasp-shaped or rib-shaped, optionally also made from a single element. If necessary, these openings can also be used for sensors.

The (plate) thickness or wall / plate thickness of a separate reinforcement plate can expediently be selected depending on the shape and / or dimensions and / or wall thickness of the mold tube, for example from 40 mm to 120 mm, in particular 50 mm for casting formats from 350 to 420 mm or 80 mm for casting formats from 420 mm to 500 mm or 100 mm for casting formats from 500 to 530 mm. The shape of a separate reinforcement plate can also be designed according to a deformation profile of the mold tube.

It can also be expedient to design separate reinforcement plates identically - or to design a separate reinforcement plate depending on its respective mold tube wall / mold tube side surface.

In particular, it can also be expedient if a separate reinforcement plate is designed to be essentially planar on its rear side facing the mold tube and / or to be curved outwards (or also again essentially planar) on its front side facing away from the mold tube - away from the mold tube .

(Panel) thickness information or wall / panel thickness information can relate to the respective minimum (panel) thickness or wall / panel thickness.

As mentioned at the outset, the invention relates, inter alia, to a continuous caster.

The continuous caster according to the invention is equipped with a mold unit according to the invention.

The continuous caster can in particular be a so-called curved continuous caster. Alternatively, the continuous caster can be a so-called vertical continuous caster.

The description of preferred embodiments of the invention given so far contains numerous features, some of which are reproduced in several combined form in the individual dependent claims. These features can, however, also be viewed individually and combined into useful further combinations. In particular, these features can be combined individually and in any suitable combination with the mold unit according to the invention and the continuous caster according to the invention.

The properties, features and advantages of the invention described above and the manner in which they are achieved will become clearer and more clearly understandable in connection with the following description of an exemplary embodiment of the invention, which is explained in more detail in connection with the figures. The exemplary embodiment serves to explain the invention and does not limit the invention to the combinations of features specified therein, not even with regard to functional features. In addition, features of the exemplary embodiment suitable for this purpose can also be explicitly viewed in isolation and combined with any of the claims.

FIG 1

eine schematische Darstellung einer Stranggießanlage mit einer Kokilleneinheit;

FIG 2

eine 3D-Ansicht der Kokilleneinheit sowie eine Kokillenträgervorrichtung, an welcher die Kokilleneinheit befestigt ist;

FIG 3

eine 3D-Ansicht der Kokilleneinheit;

FIG 4

einen Längsschnitt der Kokilleneinheit;

FIG 5

eine 3D-Ansicht der Kokilleneinheit, welche die Verstärkungsplatten an den Seitenwänden des Kokillenrohrs der Kokilleneinheit zeigt;

FIG 6

eine Schnittdarstellung der Kokilleneinheit, in welcher die Befestigung einer Verstärkungsplatte am Kokillenrohr der Kokilleneinheit abgebildet ist;

FIG 7

eine Schnittdarstellung der Kokilleneinheit, in welcher ein Verbindungselement der Befestigung einer Verstärkungsplatte am Kokillenrohr der Kokilleneinheit im Detail abgebildet ist.

Show it:

FIG 1

a schematic representation of a continuous caster with a mold unit;

FIG 2

a 3D view of the mold unit and a mold carrier device to which the mold unit is attached;

FIG 3

a 3D view of the mold unit;

FIG 4

a longitudinal section of the mold unit;

FIG 5

a 3D view of the mold unit showing the reinforcement plates on the side walls of the mold tube of the mold unit;

FIG 6

a sectional view of the mold unit, in which the attachment of a reinforcement plate to the mold tube of the mold unit is shown;

FIG 7

a sectional view of the mold unit, in which a connecting element of the fastening of a reinforcement plate on the mold tube of the mold unit is shown in detail.

Pipe mold with protector plates / protector pipe mold

FIG 1 shows schematically a continuous casting plant 2 for the continuous casting of metal products, in particular for the continuous casting of blooms. In the present exemplary embodiment, the continuous caster 2 is a curved continuous caster.

The continuous caster 2 comprises a ladle turret 4, in which two exchangeable ladles 6 are inserted, as well as a mold unit 8. The latter is attached to a mold carrier device 10 or mold cover 10 (cf. FIG 2 , in the following only mold carrier device 10), which in FIG 1 is not shown for the sake of clarity.

In addition, the continuous casting plant 2 comprises a distribution basin 12 for receiving a molten metal from the ladle 6 and for forwarding the metal melt to the mold unit 8. Furthermore, the continuous casting plant 2 has a strand guide system 14 with a cooling device (not shown in the figure) and several strand guide rollers 16 as well as a separating device 18th

A metal melt, for example liquid steel, is located in the pouring ladle 6. The molten metal is introduced from the respective pouring ladle 6 into the distributor basin 12. From there, the molten metal is introduced into the mold unit 8 via an outlet pipe 20 of the distributor basin 12.

Since a coolant 46, preferably water, is passed through the mold unit 8, the molten metal cools down on its contact surfaces with the mold unit 8 and partially solidifies, so that the molten metal emerges from the mold unit 8 in the form of a strand 22. When exiting the mold unit 8, the strand 22 has a solidified shell, while a large part of its cross section is still liquid.

With the aid of the strand guide rollers 16 of the strand guide system 14, the strand 22 emerging from the mold unit 8 is transported away and, in the process, is guided along an arc. In the strand guide system 14, the strand 22 is further cooled with the aid of the cooling device of the strand guide system 14, so that the strand 22 solidifies.

By means of the separating device 18, the strand 22 is divided into several individual pieces for the purpose of further processing and then transported away. Alternatively, the strand 22 could, for example, from one or more roll stands can be processed directly without being cut up beforehand.

FIG 2 shows a 3D view of the mold unit 8 and the aforementioned mold carrier device 10 (only partially shown) to which the mold unit 8 is attached.

The previously mentioned coolant 46, for example water, which is passed through the mold unit 8, is supplied to the mold unit 8 through the mold carrier device 10 and discharged again via the mold carrier device 10.

How out FIG 2 As can also be seen, the mold unit 8 comprises a mold tube 24.

The mold tube 24 comprises four integral side walls 26 made of copper or a copper alloy and has a rectangular cross-sectional shape with rounded corners or corner regions 50 (cf. FIG 5 and FIG 6 ). The wall thickness d _{0 of} the mold tube 24 is approximately 24 mm.

Since the continuous caster 2 in the present exemplary embodiment is a curved continuous caster, the mold tube 24 has a curved mold cavity 28. The curvature of the mold cavity 28 is achieved in that the two wider of the four side walls 26 are curved (hardly noticeable in the figures).

Furthermore, in the present exemplary embodiment, the mold cavity 28 has a rectangular shape in the cross section of the mold tube 24 with rounded corners / corner regions 50 and a length L of 410 mm and a width B of 320 mm (casting format 320 mm × 410 mm, cf. FIG 5 ), whereby in principle other dimensions of the mold cavity 28 are also possible.

The mold tube 24 is surrounded by a coolant conductive jacket 32 - with a wall thickness of approx. 8 mm -, with between the mold tube 24 and the coolant conductive jacket 32 an approx. 4 mm wide coolant gap 44 through which the coolant 46 flows (cf. FIG 6 and FIG 7 ).

Furthermore, the mold unit 8 comprises four separate reinforcement plates 30 which - outside of the coolant conduction jacket 32 - are attached to the outside of the mold tube 24 (cf. FIG 5 ).

Each individual mold tube side wall 26 has its own reinforcement plate 30 which holds it "in shape".

Next is (especially from FIG 5 ) it can be seen that those reinforcement plates 30 which are attached to the narrower side walls 26 of the mold tube 24 have a wall thickness d ₁ which is smaller than the wall thickness d _{2 of} those reinforcement plates 30 which are attached to the wider side walls 26 of the mold tube 24.

Correspondingly, those reinforcing plates 30 which are fastened to the narrower side walls 26 of the mold tube 24 are designed correspondingly narrower than those reinforcing plates 30 which are fastened to the wider side walls 26 of the mold tube 24.

In addition, the mold tube 24 has a wall thickness d ₀ that is smaller than the aforementioned wall thicknesses d ₁ , d ₂ .

In the present exemplary embodiment, the wall thickness d _{0 of} the mold tube 24 is approximately 24 mm, while the wall thickness d _{1 of} the reinforcement plates 30 attached to the narrower side walls 26 of the mold tube 24 is approximately 55 mm and the wall thickness d _{2 of} that of the wider side walls 26 of the mold tube 24 fastened reinforcement plates 30 is approximately 110 mm, whereby in principle other values for the wall thicknesses d ₀ , d ₁ , d _{2 are also} possible.

Alternatively, all reinforcement plates can have the same wall thickness d ₁ (= d ₂ ) of, for example, 75 mm.

In addition, the mold unit 8 comprises a tubular coolant box 66, in the cavity 48 of which the mold tube 24 (with its coolant conducting jacket 32 and its reinforcing plates 30) is inserted (cf. FIG 3 ).

At its upper end, the coolant box 66 has a fastening flange / coolant distribution flange 34, by means of which the mold unit 8 is fastened to the mold carrier device 10 (cf. FIG 2 and FIG 4 ) and via which the coolant 46 flows into and out of the mold unit 8 or the coolant gap 44 (cf. FIG 3 , Inflow openings 40, outflow openings 42).

At its lower end, the coolant box 66 has a castor support flange 36 with castors 38 (for supporting and guiding the thin strand shell at the mold outlet) (cf. FIG 3 ).

The connection of the castor support flange 38 and the mold unit 8 takes place via four long screws which are screwed to the fastening flange / coolant distribution flange 34 in order to be able to easily detach the castors 38 from the mold unit 8 even in the event of a break in the strand (cf. FIG 3 ). These screws are routed dry through the tubular coolant box 66 or its cavity 48 via pipes (cf. FIG 3 ) to save space and ensure easy assembly.

FIG 3 shows a 3D view of the mold unit 8. In this figure, the aforementioned coolant box 66 with its fastening flange / coolant distribution flange 34 and its castor support flange 36 and the inflow 40 and outflow openings 42 are visible.

FIG 4 shows a section through the mold unit 8, with the mold tube 24 with its mold cavity 28, the coolant conduction jacket 32, two of the reinforcement plates 30 and the coolant box 66 with its fastening flange / coolant distribution flange 34 and its caster support flange 36 being shown here in particular - in section.

FIG 5 shows a 3D view of the mold unit 8 mentioned several times before. In this figure, all four side walls 26 of the mold tube 24 and their separate / individual reinforcing plates 30 are visible.

Furthermore, in FIG 5 Numerous recesses 68 are visible in the reinforcement plates 30, which are used to attach the reinforcement plates 30 - by means of appropriate attachment systems - (cf. FIG 6 and FIG 7 ).

FIG 6 shows a sectional view of part of the mold unit 8.

In FIG 6 one of the reinforcement plates 30, part of the coolant conduction jacket 32 and part of one of the mold tube side walls 26 of the mold tube 24 are shown. In addition, in FIG 6 several (in this case three) fastening systems are shown, by means of which the illustrated reinforcement plate 30 is fastened to the illustrated, associated (respective) mold tube side wall 26.

Such a fastening system provides a connecting element 56, an adjusting screw sleeve 62 and a threaded insert 52. The threaded insert 52 is inserted into a recess 54 in the mold tube side wall 26 of the mold tube 24 shown; The screw-on screw sleeve 62 is screwed into a through-hole (with a corresponding internal thread) in the reinforcement plate 30 by means of an external thread on the outer circumference of the screw-screw sleeve 62 and penetrates through a further through hole 78 in the coolant conduction jacket 32; the connecting element 56 is in the adjusting screw sleeve 62 is inserted and screwed into the threaded insert 52 and "disappears" into the aforementioned recess 68 in the reinforcement plate 30.

FIG 7 shows a sectional view of part of the mold unit 8 with a fastening system in detail.

In FIG 7 a part of one of the reinforcement plates 30, part of the coolant conduction jacket 32 and part of one of the mold tube side walls 26 of the mold tube 24 are shown. In addition, in FIG 7 a connecting element 56 of the fastening system is shown, by means of which the reinforcement plate 30 shown is fastened to the mold tube side wall 26 shown.

The connecting element 56 is designed as a (shank / fixing) screw (here for example M12) and has a screw head 64 at its first end and a threaded section 58 at its second end, as well as a threadless shank section 60 arranged in between, the length of the shank section 60 corresponds to approximately 60% to 80% of the total length of the connecting element / screw 56.

In addition, the connecting element / screw 56 is screwed into one of the aforementioned threaded inserts 52, which is inserted into a recess 54 of the illustrated mold tube side wall 26 of the mold tube 24.

A part of the connecting element / screw 56 is surrounded by one of the aforementioned screw-on screw sleeves 62, which (on the one hand) rests on the end face of the mold tube side wall 26 and (on the other hand) supports the screw head 64 of the connecting element / screw 56 on the end face.

Furthermore, the adjusting screw sleeve 62 is secured by means of a lock nut 76 (screwed onto an external thread on the adjusting screw sleeve 62), as a result of which the fastening system is axially adjustable.

The fastening system or its stilt-like penetration 80 is sealed by means of sealing elements 72, 74.

For this purpose, the adjusting screw sleeve 62 has an annular groove 70 on its inner circumference, in which a sealing ring 72, preferably an elastomer sealing ring (O-ring), is inserted, this sealing ring 72 resting against the connecting element / screw 56. Furthermore, in the area of the further through-hole 78, a further groove 70 is made in the coolant conduction jacket 32, in which a further sealing ring 74, preferably again an elastomer sealing ring (O-ring), is inserted, this sealing ring 74 resting against the outer circumference of the screw-on screw sleeve 62 .

Each of the reinforcement plates 30 of the mold unit 8 is fastened to the associated mold tube side wall 26 of the mold tube 24 with the aid of several such fastening systems with the connecting elements / screws 56 and the adjusting screw sleeves 62 of the type described above (cf. FIG 3 and FIG 4 and FIG 6 ). The above statements in connection with the fastening systems FIG 7 (or. FIG 6 ) apply accordingly to the other fastening systems of the mold unit 8.

The reinforcement plates 30 are thus provided individually on all sides of the mold tube 24. They are floatingly connected to the mold tube 24 and the coolant conduction jacket 32 by means of the fastening systems and only support the mold tube side face / side wall 26 assigned to them.

The thermal expansions of the (other) mold tube side surfaces / side walls 26 arranged at right angles to the relevant mold tube side surface / side wall 26 thus do not influence the supporting effect.

The adjusting screw sleeves 62 are screwed into the respective reinforcement plate 30, as described above, axially adjustable. In the case of the (copper) mold tubes that are usually unmachined on the outside, this is beneficial in order to be able to compensate for manufacturing tolerances (resulting from a drawing process) and to avoid large-area machining.

One idea of the present mold unit 8 with its separate reinforcement plates 30 (protector system) is also to lay out the supporting wall, i. H. the separate reinforcement plate 30, in a floating position outside the water guide, d. H. the coolant conductive jacket 32. The thermal expansion of the (copper) mold tube has no influence.

The support wall or the separate reinforcement plate 30 is only in stiffening contact with the associated mold tube side wall 26 via sleeves or the screw-on sleeves 62 and retaining screws or connecting elements 62 and protects it from impermissible thermal warping and deformation due to the coolant pressure.

The screw-on sleeves 62 pass through the coolant conducting jacket 32 in a stilt-like manner and are sealed at the passage or at the penetration 80 with simple O-rings. The screw-on sleeves 62 enable the floating mounting and the adaptation to the non-machined outer wall of the (copper) mold tube, as is usual with small (copper) mold tubes.

The tension-compression fastening system or retaining screw system is designed to be slim in order to be able to compensate for lateral thermal expansions of an individual mold tube side wall 26. Each individual mold tube side wall 26 has its individual protector, ie reinforcement plate 30, and is held by this or this in the form. The support system is thus free from disruptive external forces and from thermal expansion of the adjacent walls at right angles.

Although the invention has been illustrated and described in more detail by the preferred exemplary embodiment, the invention is not restricted by the disclosed example and other variations can be derived therefrom without departing from the scope of protection of the invention.

List of reference symbols

2

Continuous caster

4th

Ladle turret

6

Ladle

8th

Mold unit

10

Mold carrier device

12

Distribution basin

14th

Strand guide system

16

Strand guide roller

18th

Separator

20th

Outlet pipe

22nd

strand

24

Mold tube

26th

Mold tube side face / side wall

28

Mold cavity

30th

Reinforcement plate

32

Coolant / water jacket

34

Coolant distribution flange, mounting flange

36

Caster support flange (below)

38

Castors (below)

40

Coolant inlet, inflow opening

42

Coolant outlet, discharge opening

44

Coolant gap

46

Coolant

48

cavity

50

Corner area

52

Thread insert

54

Recess

56

Connecting element, (fixing) screw

58

Threaded section

60

(threadless) screw shaft section

62

Adjusting screw sleeve

64

Screw head (head nut)

66

Coolant / water tank

68

Recess

70

Groove

72

Sealing ring / element

74

Sealing ring / element

76

Lock nut

78

Through hole

80

penetration

B.

width

L.

length

d ₀

Wall thickness (of the mold tube)

d ₁

Wall thickness (of the reinforcement plate)

d ₂

Wall thickness (of the reinforcement plate)

Claims (15)

Mold unit (8) for the continuous casting of metal products, in particular for the continuous casting of blooms, comprising a mold tube (24) with a polygonal cross-sectional shape and a coolant conductive jacket (32) surrounding the mold tube (24) and forming a coolant gap (44) with the mold tube (24) ,
marked by
several separate reinforcing plates (30) which are arranged outside the coolant conducting jacket (32) and which are non-contacting with one another and fastened to the mold tube (24). Mold unit (8) according to claim 1,
characterized in that the mold tube (24) has a plurality of mold tube side surfaces (26) and each separate reinforcement plate (30) is attached to a different mold tube side surface (26). Mold unit (8) according to claim 2,
characterized by a corresponding number of separate reinforcement plates (30) such as mold tube side surfaces (26), one of the separate reinforcement plates (30) being attached to each mold tube side surface (26). Mold unit (8) according to one of the preceding claims,
characterized in that the mold tube (24) has a rectangular cross-sectional shape with four mold tube side surfaces (26) and four separate reinforcement plates (30), each of the four separate reinforcement plates (30) being attached to a different one of the four mold tube side surfaces (26). Mold unit (8) according to one of the preceding claims,
characterized in that the separate reinforcement plate (30) is attached to the mold tube (24) in a prestressed manner. Mold unit (8) according to one of the preceding claims,
characterized by a plurality of fastening systems by means of which the separate reinforcing plates (30) are fastened to the mold tube (24),
each fastening system having at least one connecting element (56) which has a threaded section (58) and a threaded insert (52) which is inserted, in particular screwed, into a recess (54) of the mold tube (24), and wherein the connecting element (56) is screwed into the threaded insert (52) by means of its threaded section (58). Mold unit (8) according to claim 6,
characterized in that the connecting element (56) is designed as a screw (56) with a threadless screw shaft section (60), in particular with the threaded section (58) at one end of the screw (56) and a screw head (64) or one on the screw (56) screw-on head nut at another end of the screw (56). Mold unit (8) according to claim 6 or 7,
characterized in that the fastening system has an adjusting screw sleeve (62) which is screwed into a through hole (78) in the separate reinforcement plate (30) and which surrounds part of the connecting element (56), in particular the threadless screw shaft section (60), the screw-on adjustment sleeve (62) rests on the end face on the outside of the mold tube (24) or on the threaded insert (52) and in particular the screw head (64) or the head nut rests on the screw-adjustment sleeve (62) on the other end. Mold unit (8) according to claim 8,
characterized in that the adjusting screw sleeve (62) is secured in the separate reinforcement plate (30) by means of a lock nut (76). Mold unit (8) according to one of Claims 6 to 9,
characterized in that the fastening system penetrates the coolant conducting jacket (32), in particular in the shape of a stilt, the penetration (80) being sealed. Mold unit (8) according to one of the preceding claims,
characterized in that the mold tube (24), the coolant conduction jacket (32) and the separate reinforcement plates (30) are arranged in a water tank (66). Mold unit (8) according to one of the preceding claims,
characterized by a coolant distribution flange (34) for fastening the mold unit (8) to a mold carrier device (10), which has one or more coolant inlet / inlets (40) and one or more coolant outlet / outlets (42), the The coolant inlet / inlets (40) and the coolant outlet / outlets (42) of the cooling water distribution flange (34) are fluidly connected to the coolant gap (44). Mold unit (8) according to one of the preceding claims,
characterized in that the mold tube (24) has a mold cavity (28) which in the cross section of the mold tube (24) has a rectangular shape with a length (L) of at least 280 mm, preferably at least 320 mm, and / or with a width ( B) of at least 240 mm, preferably at least 280 mm, and / or that the mold tube (24) has a curved mold cavity (28). Mold unit (8) according to one of the preceding claims,
characterized in that the mold tube (24) has a wall thickness (d ₀ ) of at most 35 mm, preferably at most 30 mm, particularly preferably at most 25 mm or even 20 mm, and / or the separate reinforcing plate full-surface, clasp-shaped or rib-shaped, in particular with a wall thickness (d ₁ , d ₂ ) of 40 mm to 120 mm, and / or a shape of the separate reinforcement plate (30) according to a deformation profile of the mold tube (24). Continuous casting plant (2), in particular curved continuous casting plant, with a mold unit (8) according to one of the preceding claims.

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