EP0133896A1 - 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

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.

Since efforts are underway to now also use horizontal continuous casting plants for the casting of steel strands, it is an object of the present invention to provide a refractory duct To create a bond from juxtaposed bodies for transferring molten steel from a tundish into a mold or casting machine of horizontal 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 allows easy replacement of individual parts.

The object is achieved according to the invention in that in the refractory lining of the distribution vessel a replaceable pouring cassette provided with a drainage channel leading to the outside of the vessel and a shut-off device is arranged in a reproducible position, which has direct or indirect connection means for a pouring tube with its outlet profile traces the cross-sectional profile of the mold and there carries a mouthpiece that seals with the mold walls. 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 finally complete the sewer connection by connecting both units, that is to say by moving the pouring tube unit to the pouring cassette installed in the fixed distribution vessel, so that the assembly and assembly work required on site Disassembly work is limited 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 advantageously accessible as a wedge-shaped prefabricated component from the outside of the distributor vessel in its refractory bottom lining installed and adjusted on shaped stones arranged there. This design and arrangement is clear and allows a quick reproducible replacement of the pouring cassette, which is also useful 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 shaped stone which is flush with the bottom of the vessel 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 proposal 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 to the coupling part via an annular groove and ring spring, 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 did have proven to be particularly expedient to equip the mouthpiece with a separate muzzle tip, which is gripped directly or indirectly by the metal housing, 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, 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 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 sind Ansichten auf Isolierungen des Gießrohres nach B-B und 6 und _C-_C der Fi^{g. 1.}

Show it:

• .Fig. 1 shows a refractory channel connection, arranged between the distribution vessel and the mold, 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
• Fig. 5 are views of insulation of the pouring tube according to BB and 6 and _C - _C of Fi ^{g. 1.}

• 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 shows the partially broken top view of FIG. 9,
• 11 shows the view y according to FIGS. 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 accessible from the outside in a reinforced area of a sheet metal jacket 8 and a refractory lining 9 having a distribution vessel 1 and is adjusted by a portal-like molded block 10 and a horseshoe-shaped molded block 11, of which the appropriately formed in two parts and with an abutment groove 10a provided portal-like molded block 10 in the wall and the horseshoe-shaped molded block 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 makes a low-gap, reproducible delivery possible 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 ball head 5b, has a ball 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 6 is surrounded by insulation, which is formed in the tubular section by half-shells 31 and 32 from 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 _'"iner positioned sheet in the holding frame 34 through the sake of simplicity not illustrated means.

Above the spring 30 of the pouring tube 6, the mouthpiece 7 is connected with a counter-profiled groove 37 (FIGS. 8 and 9), which projects into the mold 2 with its mouth tip 7a and thereby cooperates in a sealing manner 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 900 ° 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. By omitting the insulation 40, a circumferential space 46 is provided under the metal housing 41, into which inert gas is introduced, of 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 s in the gap between the mold wall and the mouthpiece and air keep 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.

• Zunächst werden der Kupplungsteil 5 mit dem feuerfest angekitteten Kugelkopf 5b und die Ausgußkassette 4 mit dem eingekitteten Ausguß 15 ebenfalls mittels Kitt miteinander verbunden. Sodann wird die vormontierte Einheit 4, 15 und 5a, 5b in die in der Auskleidung 9 des Verteilergefäßes 1 vorgesehene, durch die Formsteine 10 und 11 bestimmte Position gebracht, unter Handhabung am Montageeisen 14 oder gegebenenfalls anderer Montage-Hilfsvorrichtungen. Wegen der exakten, maßgenauen Bauweise der aus feuerfestem Feuerbeton hergestellten Ausgußkassette 4 ist dabei nur verhältnismäßig wenig Fugenmörtel erforderlich. Nun wird das inklusive Blechmantel 27 fertiggestellte Gießrohr 6 einschließlich der Isolierungen 31, 32 und 33 auf dem Halterahmen 34 eines verfahrbaren Schlittens in vorbestimmter Lage befestigt. Alsdann erfolgt der Anschluß des vormontierten Mundstückes 7, 7a an das Gießrohr 6 mittels der Spannvorrichtungen 43, die sowohl die Mündungsspitze 7a mit dem Mundstück 7 über die Flächendichtung 42 als auch das Mundstück 7 mit dem Gießrohr 6 über eine Spezialdichtung verbinden. Schließlich werden die in der beschriebenen Weise auf dem Schlitten-Halterahmen 34 montierten Teils 6, 7 und 7a mit dem Schlitten in Position zum Kupplungsstück 5 gebracht und der Kugelsitz 25 mit dem Kugelkopf 5b über die besagte Spezialdichtung unter Aufbringung von Anpreßkraft zusammengeschlossen. Die Festlegung der Gießposition erfolgt am Halterahmen-Schlitten. Als letztes bringt man die ebenfalls verstellbare Gießmaschine bzw. Kokille 2 in Arbeitsstellung.

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 of all, 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 brought into position with the slide 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 (17)

1. Refractory channel connection of bodies placed against one another for transferring, in particular, steel melt from a distribution vessel into a mold of horizontal continuous casting plants with moving mold walls in the form of endless belts, characterized in that in the refractory lining (11) of the distribution vessel (1) one with a to the outside of the vessel leading drain channel (17) and a shut-off device (15, 16) provided interchangeable pouring cassette (4) is arranged in a reproducible position, which has direct or indirect connection means (5, 5a, 5b) for a pouring tube (6) with its Exit profile (29) traces the cross-sectional profile of the mold (2) and carries a mouthpiece (7) which seals with the mold walls. 2. Channel connection according to claim 1, characterized in that the pouring cassette (4) as a wedge-shaped finished component from the outside of the distribution vessel (1) accessible in its refractory bottom lining (9) installed and adjusted there arranged counter-profiled stones (10, 11). 3. Channel connection according to claim 2, characterized in that the pouring cassette (4) with profiled edges of the outer end face in an abutment (10a) of a portal-like shaped block (10) built into the wall of the lining (9) and with the flanks and the inner The end face also fits flush into a horseshoe-shaped shaped block (11) recessed flush into the bottom of the lining (10). 4. Channel connection according to claims 2 and 3, characterized in that the pouring cassette (4) carries the spout (15) of a plug closure device on the vessel bottom side and has an adjoining outflow channel (17) of rectangular flow cross-section. 5. Duct connection according to claim 2 to 4, characterized in that the pouring cassette (4) has a projecting over the outer end face mounting plate (14). 6. Channel connection according to claims 2 to 5, characterized in that the pouring cassette (4) consists of chemically or hydraulically setting refractory refractory concrete, in the optionally reinforcing or assembly iron (14) and / or steel fibers are integrated in the flow area of the melt. 7. Channel connection according to claims 2 to 6, characterized in that the pouring cassette (4) on the outer end face connecting elements (18, 19, 5a) for subsequent channel members (5 or 6). 8. Channel connection according to claims 1 to 7, characterized in that the pouring cassette (4) on the outer end face carries a circular groove (18) and flank guides (19) into which a circular spring (22) and flank surfaces (21) of a coupling part ( 5a) fit, which in turn has a ball head (5b) as a connecting element for the pouring tube (6). 9. Channel connection according to claim 8, characterized in that on the coupling part (5a) via ring spring (23) and annular groove (24) the ball head (5b) is connected and in the coupling part (5a) there is a change in the channel cross-section on the round profile, which which connects to the mold (2) or the pouring tube (6), the inclined channel of the ball head (5b). 10. Duct connection according to claim 1 and 9, characterized in that a flange (6a) with a ball head seat (6b) and a flat surface (6c) is provided at the inlet end of the pouring tube (6) and the flange area over a mortar layer (26) is a sheet metal jacket (27) carries, with which the tube (6) is held in an adjustable metallic holding frame (34). 11. Channel connection according to claim 9 and 10, characterized in that the pouring tube (6) is provided with an outer insulation in the form of half-switches (31, 32) and at the outlet end (28) with a bordered mat insulation (33) made of ceramic fiber material. 12. Channel connection according to claims 1, 10 and 11, characterized in that the outlet end (28) of the pouring tube (6) surrounding the free outlet profile (29) sealing spring (30) for plugging in the mouthpiece provided with a counter-profiled sealing groove (37) (7) has. 13. Channel connection according to claim 1 and 12, characterized in that the mouthpiece (7) consists of a molten steel repellent material and is encased over an outer insulation (40) by a form-fitting metal housing (41) which with a at the mouth tip (7a) of the mouthpiece (7) provided peripheral edge (39) flush with the surface. 14. Channel connection according to claim 13, characterized in that the mouthpiece (7) on the pouring tube (6) on the metal housing (41) by means of the pouring tube holding frame (34) articulated clamping devices (43) is held. 15. Channel connection according to claim 14, characterized in that the mouthpiece (7) has a separate, from the metal housing (41) directly or indirectly gripped mouth tip (7a) and between the mouthpiece (7) and mouth tip (7a) has a centered, flat ground surface seal (42) is provided. 16. Channel connection according to claim 15, characterized in that the metal housing is connected to the mouth tip (7a) via countersunk plug bolts (44). 17. Channel connection according to claims 12 to 16, characterized in that in the area of the surface seal (42) from the outer insulation free peripheral space (46) with inert gas connection and gas outlet bores in the metal housing (41) are provided.

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