EP0133896B1 - Assembled refractory feeding conduit for horizontal continuous casting - Google Patents

Abstract

A refractory conduit assembly for the transfer of molten steel from a discharge vessel to an ingot mold of a horizontal continuous casting plant includes a replaceable spout member adapted to be removably connected at a predetermined location to the refractory lining of a vessel. The spout member has therethrough a discharge channel to receive from the interior of the vessel a flow of molten steel. A shut off device is provided to interrupt the flow to the discharge channel. A casting tube has therethrough a flow passage with inlet and outlet ends. A coupling device connects the inlet end of the flow passage to the discharge channel, such that the flow of molten metal passes through the casting tube. The outlet end of the flow passage has an altered cross-sectional configuration adapted to that of the ingot mold. A nozzle has an inlet end connected to the casting tube and an outlet end having thereat a portion to sealingly contact walls of the ingot mold. The nozzle has therethrough a flow channel to pass the flow of molten steel from the casting tube to the ingot mold.

Description

The invention relates to a refractory duct connection made up of bodies placed next to one another for transferring, in particular, steel melts from a distributor vessel (1) into a mold (2) of horizontal continuous casting plants.

Horizontal continuous casting plants have so far been used successfully for casting non-ferrous metals such as lead, zinc, copper and the like. They have molds, the walls of which are formed by endless, cooled belts, as a result of which relatively high casting speeds of around 10 m per minute and thus correspondingly high casting rates are achieved with relatively little stationary equipment in the plant. The liquid metal is fed from the distributor vessel to the mold via an open, fire-proof channel.

In contrast, the continuous casting of liquid steel is preferably carried out in vertically oscillating molds into which an immersion tube, which is connected to the distributor vessel in an airtight and vertical manner, dips with the mouth under the steel bath level, in order to prevent atmospheric oxygen from reaching the steel melt. The casting speeds are a maximum of 3 to 4 m per minute, which also means that the casting capacities remain limited, although the stationary equipment is considerable due to the required intermediate deck.

From the European application EP-A 0123 121, which belongs to the state of the art according to Art. 54 (3) EPC, a refractory duct connection is described as for introducing molten steel into double-belt casting machines. Via this feed device, molten steel is introduced into a double-belt casting machine with moving mold walls from a front container while avoiding air access. To prepare for the casting process, a cast body that can be moved and rotated in a separate carriage about a horizontal swivel axis is made (pouring tube can be connected at the point of separation by means of a ball joint. A ball socket and a ball pin each belong to different parts, namely the attachment container and the pouring body. The pouring body is In the manner of a rocker, it can be locked in different inclined positions as well as laterally adjustable transversely to its longitudinal extension. The outlet profile of the casting body is adapted to the cross-sectional profile of the mold and the casting body carries a mouthpiece which seals with the mold walls.

Since efforts are now underway to now also use horizontal continuous casting plants for the casting of steel strands, it is the object of the present invention to provide a refractory channel connection made of bodies placed against one another for transferring molten steel from a tundish into a mold or casting machine of horizontal To create continuous casting plants, which is reliable and airtight to avoid reoxidation of the molten steel, and has a simple structure which is suitable for quick assembly and which also permits the replacement of individual parts without problems.

The object is achieved by the features of claim 1.

This results in a channel connection from two relatively easy-to-use basic units, namely a pouring cassette that can be pre-assembled with the shut-off device and the connection means for the pouring tube and can be installed in the vessel lining, and a pouring tube that is connected as an adjustable unit together with the mouthpiece protruding into the mold can. It is possible to prepare the two structural units largely individually for their use, in order to then connect the sewer by combining both units, i. H. to be completed by moving the pouring tube unit to the pouring cassette installed in the fixed distributor vessel, so that the assembly and disassembly work required on site is kept to a minimum. In addition, individual parts of the building units can be exchanged in a simple manner or usable individual parts of useless building units can be used again. In addition, the individual parts can be connected to one another in a simple, operationally reliable and airtight manner in the refractory field. The pouring cassette is installed as a wedge-shaped prefabricated component accessible from the outside of the distribution vessel in its refractory bottom lining and adjusted on shaped stones arranged there. This design and arrangement is clear and allows a quick exchange of the pouring cassette in a reproducible position by the cassette with profiled edges provided on the outer end face in an abutment of a portal-like shaped stone and with the flanks and the inner end face in a horseshoe-shaped, with the Flush the bottom of the molded stone also fits flush. Primarily used as a shut-off device is a stopper closure device, the spout of which is arranged in the bottom plane of the vessel lining in the spout cassette and has a drainage channel of rectangular cross section, which allows a comparatively low overall height. For easy handling of the pouring cassette, a mounting iron is provided which protrudes over the outer end face. The pouring cassette preferably consists of chemically or hydraulically setting refractory refractory concrete with possibly integrated reinforcement or assembly iron and / or steel fiber additive in the flow area of the melt.

Another embodiment of the invention consists in the interposition of a coupling part between the pouring cassette and the pouring tube, both of which can also be connected directly to one another, for which purpose the pouring cassette then carries corresponding connecting elements on the outer end face. In the former case, the outer end face of the pouring cassette is equipped with a circular groove and flank guides, into which a circular spring and flank surfaces of the coupling part fit, which in turn has a ball head as a connecting element for the pouring tube. It is advantageous from a manufacturing point of view if the ball head is connected as a separate part via an annular groove and ring spring to the coupling part, in the flow channel of which the rectangular flow cross section of the pouring cassette is converted to the round cross section of the pouring tube, while in the ball head channel the transition to the angle of inclination takes place the mold takes place.

Furthermore, the invention proposes to provide a flange with a spherical head seat and a flat surface at the inlet end of the pouring tube and to cover the flange area with a sheet metal jacket by means of a mortar layer, with which the pouring tube is held in an adjusted manner in a metallic frame. Such a construction of the pouring tube enables fitting connections to the coupling part and to the mouthpiece, in which the sheet metal jacket, which is used several times on new tubes and can be mortared with the help of a template for the exact fit, the conditions for a perfect storage of the pouring tube in the metallic frame and for the transfer of contact forces is fulfilled. The pouring tube is expediently provided with external insulation in the form of half-shells and at the outlet end with a bordered mat insulation made of ceramic fiber material. In contrast to the desired insulating effect, when the pouring tube is clamped in the holding frame, a certain compensation effect is achieved while compensating for dimensional tolerances in the outside diameter of the pouring tube, the outlet end of which has a sealing spring surrounding the free outlet profile for fitting the mouthpiece provided with a counter-profiled sealing groove.

Another feature of the invention is that the mouthpiece consists of a material that repels molten steel and is encased over an external insulation by a form-fitting metal housing, which ends flush with a peripheral edge provided at the mouth tip. Designed in this way, the mouthpiece remains largely free of lumps in the flow channel and is able to withstand the stresses of the internally acting steel melt and the cooled mold walls that pass by at a comparatively high speed, and to achieve extremely satisfactory service lives in practice. In addition, the mouthpiece can be attached to the pouring tube with the metal housing by means of tensioning devices articulated on the pouring tube holding frame without any problems and reliably. It has proven to be particularly expedient to equip the mouthpiece with a separate muzzle tip, which is gripped behind the metal housing directly or indirectly, and to provide a centered, flat-ground surface seal between the mouthpiece and the muzzle tip. Accordingly, for example, a prematurely worn muzzle tip can be easily replaced or, in an economical manner, a material, preferably boron nitride, can be used, which is more expensive than the material for the mouthpiece. but offers more security with regard to the free flow of the molten steel and the wear resistance. In particular, the metal housing can be connected to the muzzle tip via countersunk plug pins.

With special attention to the problem of preventing the ingress of air into the contact area between the mouthpiece and the mold, according to the invention a circumferential space free of insulation with an inert gas connection is provided on the mouthpiece in front of the surface seal to the mouth tip within the metal housing perforated all around there, so that a gas barrier is established that effectively shields the inside of the mold from the outside air.

The invention is explained below, for example with reference to the drawing.

• Fig. 1 eine zwischen Verteilergefäß und Kokille angeordnete feuerfeste Kanalverbindung bestehend aus einer Ausgußkassette, einem Kupplungsteil, einem Gießrohr und einem Mundstück im Längsschnitt,
• Fig. 2 die Draufsicht auf eine Ausgußkassette im Boden des Verteilergefäßes,
• Fig. 3 einen Formstein zur Lagerung der Ausgußkassette in Frontansicht,
• Fig. 4 die Ansicht auf den Kupplungsteil nach A-A der Fig. 2 und
• Fig. 5 und 6 sind Ansichten auf Isolierungen des Gießrohres nach B-B und C-C der Fig. 1.

Show it :

• 1 shows a refractory channel connection arranged between the distribution vessel and the mold, consisting of a pouring cassette, a coupling part, a pouring tube and a mouthpiece in longitudinal section,
• 2 is a top view of a pouring cassette in the bottom of the distributor vessel,
• 3 is a molded block for storing the pouring cassette in front view,
• Fig. 4 shows the view of the coupling part according to AA of Fig. 2 and
• 5 and 6 are views of insulation of the pouring tube according to BB and CC of FIG. 1st

• Fig. 7 das Gießrohrende in Vorderansicht,
• Fig. 8 im Längsschnitt ;
• Fig. 9 ebenfalls im Längsschnitt das an das Gießrohr anschließbare Mundstück,
• Fig. 10 die teilweise aufgebrochene Draufsicht zu Fig. 9,
• Fig. 11 die Ansicht y nach Fig. 10 und
• Fig. 12 die Ansicht z nach Fig. 10.

The following figures illustrate on a larger scale:

• 7 the pouring tube end in front view,
• Fig. 8 in longitudinal section;
• 9 also in longitudinal section the mouthpiece connectable to the pouring tube,
• 10 is the partially broken plan view of FIG. 9,
• 11 is the view y of FIG. 10 and
• 12 shows the view z according to FIG. 10.

In FIG. 1, 1 means a distributor vessel, for example a tundish, which is only shown in the pouring area, from which liquid steel is fed to a mold 2, which is also only indicated, or to a casting machine with moving mold walls. For this purpose, a fire-proof duct connection 3 which is airtight on all sides is provided, which consists of a pouring cassette 4, a coupling part 5 and its pouring tube 6 with a mouthpiece 7.

The pouring cassette 4 is laterally supported from the outside accessible in a reinforced area of a metal jacket 8 and a fireproof lining 9 having distribution vessel 1 and is thereby adjusted by a portal-like molded block 10 and a horseshoe-shaped molded block 11, of which the portal-like molded block 10, which is expediently formed in two parts and provided with an abutment groove 10a, into the wall and the horseshoe-shaped stone 11 is installed in the bottom of the refractory vessel lining 9. Both shaped stones 10 and 11 serve the pouring cassette 4 as an abutment and determine their position in the vessel lining 9. On the sides facing the inside of the vessel, the shaped stones 10 and 11 are flush with the inner walls of the vessel, to which a mass layer 12 is applied. For easy replacement, the pouring cassette 4 is tapered on the flanks and on the support side towards the inner end face and provided with a mounting iron 14 (FIG. 2) which, mortared in a groove, surrounds the flanks and the inner end face and both ends over the protrudes the outer end face. On the top, ie on the bottom of the vessel, the pouring cassette 4 is equipped with an inserted pouring spout 15, which cooperates with a plug 16 as a closure for draining the melt from the vessel 1 and opens into an outflow channel 17 of rectangular cross-section which widens slightly in the outflow direction. The channel 17 leads to the outer end face of the pouring cassette 4, where a circular profile groove 18 and the counter profile for the abutment groove 10a of the portal-like shaped block 10 and vertical flank guides 19 are provided for the coupling part 5a. The pouring cassette 4 is preferably a refractory prefabricated component made of hydraulically or chemically bonded refractory concrete with a steel fiber additive in the wall area of the drain channel 17. Such components have an exact construction, which enables a low-joint, reproducible delivery after each exchange. The spout 15 and the mounting iron 14 are provided as replaceable elements on the spout cassette 4.

The pouring channel 17 of the pouring cassette 4 is continued by the channel section 20 in the coupling part 5 which has a round profile and has a spherical head 5b in which a channel section 20a having the inclination of the pouring tube 6 and the mold 2 is arranged. The coupling part 5 has the shape of a round body with parallel flank surfaces 21 (FIG. 2) and a circular spring 22 as counter profiles to the flank guides 19 and the circular groove 18 on the outer end face of the pouring cassette 4. Coupling part 5a and ball head 5b are manufactured separately for manufacturing reasons and assembled via an annular spring 23 and an annular groove 24 to form a component.

The pouring tube 6 connected to the coupling part 5 has a flange 6a. which, as a counter-profile to the spherical head 5b, has a spherical head seat 6b, a flat surface 6c and a sheet metal jacket 27 over a mortar layer 26. At the outlet end 28, the pouring tube is flattened in a wedge shape onto a rectangular exit profile 29 of the same shape as the mold, which is surrounded by a spring 30 (see FIGS. 7 and 8). On the outer circumference, the pouring tube is surrounded by insulation, which is formed in the tubular section by half-shells 31 and 32 made of molded ceramic fiber material, while the wedge-shaped end 28 has an insulating mat 33, which is fastened, for example, by means of metal strips. 5 and 6, the half-shells 31 and 32 have a substantially semicircular cross-section and, in addition, the half-shells 32 are provided with parallel mating surfaces 32a for insertion into a holding frame 34, which is part of an adjustable slide (not shown further) and is used for positioning the pouring tube 6 . For this purpose, the approximately U-shaped holding frame 34 in cross section has a support surface 35 for the sheet metal jacket 27 on the flat surface 6c of the pouring tube 6, which is also supported by the sheet metal jacket 27 on the free end face 36 of the holding frame 34. The pouring tube 6 is clamped in its position in the holding frame 34 by means not shown for the sake of simplicity.

About the spring 30 of the pouring tube 6 with a counter-profiled groove 37 connects the mouthpiece 7 (Fig. 8 and Fig. 9), which projects into the mold 2 with its mouth tip 7a and thereby cooperates sealingly with the mold walls moving in the withdrawal direction. Accordingly, the outer shape of the mouthpiece 7 is a body corresponding to the mold cross section, in the present case a prismatic body, the flow channel 38 of which widens on all sides towards the mouth tip. At the outlet, the refractory material of the muzzle tip 7a has sealing contact with the mold walls via a circumferential edge 39 provided on the muzzle edge, whereas the remaining cross section of the muzzle tip 7a and mouthpiece 7 is kept smaller for applying a circumferential insulation 40 made of ceramic fiber paper and one with the circumferential edge 39 flush metal housing 41. This is made of a heat-resistant special alloy, which still has a strength of 10 kp / mm ² at 9005 ° C. The mouth tip 7a is a separate workpiece and is coupled to the mouthpiece 7 by means of pressure-cut surfaces 42, preferably with centering by means of centering bolts (not shown). Here, the contact pressure is transmitted to the metal housing 41 and from there via bolts 44 which engage in the mouth tip 7a by means of clamping devices 43 which are hinged to the holding frame 34 and hold the mouthpiece 7 on the pouring tube 6. For this purpose, the metal housing has direct contact with sheet shapes 45 of the muzzle tip 7a at the locations provided for the bolts 44, while leaving out the insulation 40. To initiate the contact pressure on the metal housing 41, hooks 43a belonging to the clamping devices 43 are bent out of the latter. A circumferential space 46 is underneath the metal housing 41 by omitting the insulation 40 provided, into which inert gas is introduced, from lines which can be laid within the metal housing 41 in a manner not shown. In the area of the peripheral space 46, the metal housing 41 is provided with holes 47, so that the inert gas exits into the gap between the mold wall and the mouthpiece 7 and keeps air away from the mold.

As already stated at the beginning, the pouring cassette 4 consists of refractory refractory concrete. The coupling part 5 and the pouring tube 6, on the other hand, are advantageously made of a graphite-containing high-alumina material. Particular attention is paid to the mouthpiece 7, which acts as a strand nozzle, including the mouth tip 7a, both of which are made from a material that repels the molten metal, preferably from alumina-graphite material, ceramic cast quartz material or high-strength zirconium oxide material.

The assembly of the fire-proof duct connections, for example for the horizontal casting of a billet strand of 70 x 180 mm cross-section with a casting performance of one ton per minute and a casting speed of 10 m per minute, is carried out as follows:

First, the coupling part 5 with the fireproof cemented ball head 5b and the spout cassette 4 with the cemented spout 15 are also connected to one another by means of putty. Then the preassembled unit 4, 15 and 5a, 5b is brought into the position provided in the lining 9 of the distribution vessel 1 and determined by the shaped stones 10 and 11, while handling the assembly iron 14 or possibly other assembly auxiliary devices. Because of the exact, dimensionally accurate construction of the pouring cassette 4 made of refractory refractory concrete, only relatively little grout is required. Now the pouring tube 6, including the sheet metal jacket 27, including the insulation 31, 32 and 33, is fastened on the holding frame 34 of a movable carriage in a predetermined position. Then the pre-assembled mouthpiece 7, 7a is connected to the pouring tube 6 by means of the clamping devices 43, which connect both the mouth tip 7a with the mouthpiece 7 via the surface seal 42 and the mouthpiece 7 with the pouring tube 6 via a special seal. Finally, the parts 6, 7 and 7a mounted on the slide support frame 34 in the manner described are brought into position with the slide in relation to the coupling piece 5 and the ball seat 25 is connected to the ball head 5b via said special seal with the application of contact pressure. The casting position is determined on the holding frame slide. Finally, the casting machine or mold 2, which is also adjustable, is brought into the working position.

Claims (15)

1. Refractory runner connection comprising juxtaposed bodies for conveying particularly steel melt from a distributor vessel (1) into a mould (2) of horizontal continuous casting installations with moving mould walls in the form of endless bands, whereby a discharge cassette (4) is provided in the lining of the distributor vessel (1) which is provided with a discharge passage leading to the exterior of the vessel and a shut-off device (15, 16) and has direct or indirect connecting means (5, 5a, 5b) for a pouring tube (6), the outlet profile (29) of the pouring tube (6) is matched to the cross sectional profile of the mould (2) and there carries a nozzle (7) sealing with the mould walls, the discharge cassette (4) being replaceably arranged in a reproducible position in that it is mounted as a wedge-shaped prefabricated component accessible from the exterior of the distributor vessel (1) in its refractory bottom lining (9) and is adjusted by complementarily profiled shaped members (10, 11) arranged there, whereby the discharge cassette (4) also fits snugly with profiled edges of the outer end face into a side wall (10a) of the portal-like shaped brick (10) and with the flanks and the inner end face into a horseshoe-shaped brick (11) set flush in the floor of the lining (10).

2. Runner connection as claimed in Claim 1, characterised in that on the vessel floor side the discharge cassette (4) carries the nozzle (15) of a stopper valve device and has an outflow passage (17) of rectangular flow cross section connected thereto.

3. Runner connection as claimed in Claims 1 and 2, characterised in that the discharge cassette (4) has a mounting plate (14) projecting beyond the outer end face.

4. Runner connection as claimed in Claims 1 to 3, characterised in that the discharge cassette (4) comprises chemically or hydraulically setting refractory fire concrete in which optionally reinforcement or mounting brackets (14) and/or steel fibres are bonded in the flow region of the melt.

5. Runner connection as claimed in Claims 1 to 4, characterised in that on the outer end face the discharge cassette (4) has connection elements (18, 19, 5a) for subsequent runner members (5 or 6).

6. Runner connection as claimed in Claims 1 to 5, characterised in that on the outer end face the discharge cassette (4) carries a circular groove (18) and flank guides (19) in which a circular tongue (22) and flank surfaces (21) of a coupling member (5a) fit which for its part has a ball end (5b) as a connecting element for the pouring tube (6).

7. Runner connection as claimed in Claim 6, characterised in that the ball end (5b) is connected to the coupling member (5a) via annular tongue (23) and annular groove (24) and in the coupling member (5a) there is a change of the passage cross section to round shape, connected to which is the passage of the ball end (5b) which is inclined the same as the mould (2) or the pouring tube (6).

8. Runner connection as claimed in Claims 1 to 7, characterised in that at the inlet end of the pouring tube (6) a flange (6a) with a ball end seat (6b) and a flat surface (6c) is provided and the flange region carries a sheet metal shell (27) with the interposition of a mortar layer (26), with which shell the tube (6) is adjustably mounted in a movable metal mounting frame (34).

9. Runner connection as claimed in Claims 7 and 8, characterised in that the pouring tube (6) is provided with an outer insulation in the form of half shells (31, 32) and at the outlet end (28) with an enclosed mat insulation (33) of ceramic fibre material.

10. Runner connection as claimed in Claims 1, 8 and 9, characterised in that the outlet end (28) of the pouring tube (6) has a sealing tongue (30) surrounding the free outlet profile (29) for plug connecting the nozzle (7) provided with a complementarily profiled sealing groove (37).

11. Runner connection as claimed in Claims 1 and 10, characterised in that the nozzle (7) comprises a material which repels steel melt and is enclosed by a form-sealing metal housing (41) with the interposition of an outer insulation (40) which housing forms a flush surface seal with a peripheral edge (39) provided at the nozzle tip (7a) of the nozzle (7).

12. Runner connection as claimed in Claim 11, characterised in that the nozzle (7) is mounted on pouring tube (6) via the metal housing (41) by means of the clamping devices (43) pivotally connected to the pouring tube mounting frame (34).

13. Runner connection as claimed in Claim 13, characterised in that the nozzle (7) has a separate nozzle tip (7a) behind which the metal housing (41) engages directly or indirectly and a centred plane ground surface seal (42) is provided between nozzle (7) and nozzle tip (7a).

14. Runner connection as claimed in Claim 13, characterised in that the metal housing is connected to the nozzle tip (7a) by flush head insertion pegs (44).

15. Runner connection as claimed in Claim 14, characterised in that a peripheral space (46) free from the outer insulation and with an inert gas connection and gas outlet bores are provided in the metal housing (41) in the region of the surface . seal (42).

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