Refractory casting nozzle for a changing device arranged at the outlet of a metallurgical vessel

Abstract

Refractory casting nozzle for a changing device arranged at the outlet of a metallurgical vessel is provided with a top side refractory plate, which is provided with an abutting surface at each of two opposing end faces. During a change, the casting nozzle can either be moved against the one abutting surface of a top side plate of an adjacent casting nozzle or be pushed out from this casting nozzle. This top side plate is provided, in the one abutting surface, with a centering element protruding on both sides of this and in the opposite abutting surface with a bevelling on both sides, designed such that, during a change, the casting nozzle cooperates, with its centering elements with the bevellings of the adjacent identically designed casting nozzle, thus bringing about a guiding of the two casting nozzles.

Claims

1. A refractory casting nozzle, comprising: a tubular part; a top side refractory plate on a top side of the tubular part and which includes front and rear abutting surfaces on opposite front and rear end faces, a first lateral side surface and a second lateral side surface on an opposite side of the top side refractory plate from the first lateral side surface, the front abutting surface having an end region alongside the first lateral side surface and another end region alongside the second lateral side surface and the rear abutting surface having an end region alongside the first lateral side surface and another end region alongside the second lateral side surface; two centering elements protruding outward from the front abutting surface, each of the two centering elements protruding outward on a respective one of the two end regions of the front abutting surface; and a sheet jacket on the first and second lateral side surfaces and part of the front and rear abutting surfaces, the top side refractory plate including two bevellings each on a respective one of the two end regions of the rear abutting surface, the bevelling and the centering element on the end regions of the front and rear abutting surfaces alongside the first lateral side surface having a cooperating profile and the bevelling and the centering element on the end regions of the front and rear abutting surfaces alongside the second lateral side surface having a cooperating profile, the sheet jacket having a width between upper and lower surfaces of the top side refractory plate in portions on the front and rear abutting surfaces that is less than a width in portions on the first and second lateral side surfaces, and the front and rear abutting surfaces protrude beyond the sheet jacket and provide contact surfaces of the top side refractory plate adjacent the upper surface of the top side refractory plate.

2. The refractory casting nozzle according to claim 1, wherein the top side refractory plate has a first corner region between the front abutting surface and the first lateral side surface, a second corner region between the front abutting surface and the second lateral side surface, a third corner region between the rear abutting surface and the first lateral side surface, a fourth corner region between the rear abutting surface and the second lateral side surface, each of the centering elements being in a respective one of the first and second corner regions and each of the bevellings being in a respective one of the third and fourth corner regions.

3. The refractory casting nozzle according to claim 2, wherein the cooperating profile of the bevelling and the centering element on the end regions of the front and rear abutting surfaces alongside the first lateral side surface and the cooperating profile of the bevelling and the centering element on the end regions of the front and rear abutting surfaces alongside the second lateral side surface is provided by the bevellings having an angle of inclination which is the same as an angle of inclination of a contact surface of the centering elements.

4. The refractory casting nozzle according to claim 3, wherein the angle of inclination of each of the bevellings and of the contact surfaces of each of the centering elements is between 30 and 60.

5. The refractory casting nozzle according to claim 3, wherein the angle of inclination of each of the bevellings and of the contact surfaces of each of the centering elements is 45.

6. The refractory casting nozzle according to claim 1, wherein the centering elements are part of the sheet jacket.

7. The refractory casting nozzle according to claim 1, wherein the centering elements are fixed to the sheet jacket.

8. The refractory casting nozzle according to claim 1, wherein the bevellings being are surrounded by the sheet jacket.

9. The refractory casting nozzle according to claim 1, wherein the sheet jacket is a metallic sheet jacket.

10. The refractory casting nozzle according to claim 1, wherein the top side refractory plate further includes a sliding surface on a top configured for contact with a refractory base plate and wherein an upper edge of the sheet jacket alongside the abutting surfaces is spaced from the sliding surface.

11. The refractory casting nozzle according to claim 1, wherein the cooperating profile of the bevelling and the centering element on the end regions of the front and rear abutting surfaces alongside the first lateral side surface and the cooperating profile of the bevelling and the centering element on the end regions of the front and rear abutting surfaces alongside the second lateral side surface enables contact between the bevellings on the refractory casting nozzle and centering elements on an additional refractory casting nozzle having the same construction as the refractory casting nozzle and contact between the centering elements on the refractory casting nozzle and bevellings on another additional refractory casting nozzle having the same construction as the refractory casting nozzle.

12. The refractory casting nozzle according to claim 1, wherein a length of the front abutting surface between the centering elements and a length of the rear abutting surface between the bevellings are greater than a hole diameter of a flow through in a center of the tubular part.

13. The refractory casting nozzle according to claim 1, wherein the top side refractory plate further includes a sliding surface on a top configured for contact with a refractory base plate and bearing surfaces on a bottom configured for contact with mechanical guiding and lifting push means of a changing device.

14. The refractory casting nozzle according to claim 1, wherein the angles of inclination of the bevellings are configured such that, during a change by a drive mechanism of a changing device, pushing forces acting upon the refractory casting nozzle are directed toward a center of a flow through of the tubular part.

15. The refractory casting nozzle according to claim 1, wherein each of the centering elements includes an angled contact surface.

16. In a changing device at the outlet of a metallurgical vessel including mechanical guiding means, lifting push means, a linear actuator with a push rod and a refractory base plate or an inlet nozzle, the improvement comprising: the refractory casting nozzle of claim 1 being movable by the changing device into a casting position below the refractory base plate or the inlet nozzle and away from the casting position, the push rod including a U-shaped shoe with guide elements on a front side that are configured to engage the bevellings of the top side refractory plate of the refractory casting nozzle and, when striking the bevellings, exert forces that act in a direction inward into the top side refractory plate.

17. The improvement to the changing device according to claim 16, wherein the top side refractory plate further includes a sliding surface on a top configured for a sealing contact with the refractory base plate or the inlet nozzle and bearing surfaces on a bottom configured for contact with the mechanical guiding means and lifting push means of the changing device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention and further advantages of same are explained in more detail below using an embodiment example, with reference to the drawings.

(2) FIG. 1 is a perspective view of a refractory casting nozzle according to the invention;

(3) FIG. 2 is a top view of the top side refractory plate of the casting nozzle according to FIG. 1;

(4) FIG. 3 is a partial longitudinal view of the casting nozzle according to FIG. 1 at the top side of the refractory plate;

(5) FIG. 4 is a perspective view of two casting nozzles in a changing device according to the invention, whereas only the rear mechanical sliding means of the device are in principle showed; and

(6) FIG. 5 is a perspective view of two metering nozzles in a changing device according to the invention, whereas also only the rear mechanical sliding means of the device are in principle showed.

DETAILED DESCRIPTION OF THE INVENTION

(7) The refractory casting nozzle 1 shown in FIGS. 1-3 is provided as a dipping tube for a strand casting system casting molten steel. It is made from refractory ceramic material in one or more parts and is composed of a tube or tubular part 2 with a flow through 6 and a top side refractory plate 3 with a sheet jacket 9. It is suitable as a casting or dipping tube, metering nozzle or the like in corresponding changing devices in tundish, ladles or other containers when casting molten material.

(8) The top side refractory plate 3 of the casting nozzle 1 has, at the top, a sliding surface 3 and an abutting surface 7a, 7b each for two opposing end surfaces, which serve to ensure that the casting nozzle 1 can be brought into tight contact against respectively an abutting surface of the top side plate of an adjacent casting nozzle during a change.

(9) According to the invention, this top side plate 3 is provided, in the one abutting surface 7b, with a centering element 5a, 5b protruding on both sides of same, and in the opposite abutting surface 7a with a bevelling 4a, 4b on both sides of same.

(10) The bevellings 4a, 4b are arranged in the one side corner regions of the top side plate 3. They have an angle of inclination as shown of preferably 45 and are positioned to one another such that, during the changing process, the pushing forces K1, K2, which are introduced for instance by a push rod of a linear actuator of a changing device, acting thereupon inwards of the casting nozzle 1 and extending parallel to the plane of the sliding surface of the top side plate 3. As shown in FIG. 2, the angle of inclination is defined as an angle between a plane parallel to the lateral side surface of the sheet jacket 9 or side surface of the top side refractory plate 3 of the casting nozzle 1 that underlies that portion of the sheet jacket 9, and a plane parallel to the surface of the sheet jacket 9 that overlies the bevelling 4a. A similar angle of inclination is defined for bevelling 4b on the opposite side of the abutting surface 7a.

(11) Instead of these pushing forces K1 or K2 in this direction inwards it could be used a pushing force in the moving direction, which would be acting on the abutting surface 7a of the top side plate 3 or visa vis on the abutting surface 17b of the other plate 13 in the opposite direction, thus perpendicularly on the respective abutting surface 7a, 17b.

(12) The centering elements 5a, 5b are positioned for their part in the front end regions of the top side plate 3 as protruding parts of the sheet jacket 9. As can be seen from FIG. 2, they are designed wedge-shaped, for instance triangular or similar, wherein the angle of inclination thereof is equal to that of the bevellings 4a, 4b. With the same angle of inclination, the bevelling 4a, 4b on each side of the abutting surface 7b has a cooperating or complementary profile to the centering element 5a, 5b on the respective side of the abutting surface 7a. As shown in FIG. 2, the angle of inclination is defined as an angle between a plane parallel to the angled contact surface of the centering element 5b (on an opposite side of the wedge-shaped centering element 5b from the side that is alongside the side surface of the top side refractory plate 1), and a plane parallel to the lateral side surface of the sheet jacket 9 or side surface of the top side refractory plate 3 of the casting nozzle 1 that underlies that portion of the sheet jacket 9 (the same plane that defines the angle of inclination ). A similar angle of inclination is defined for centering element 5a on the opposite side of the abutting surface 7b.

(13) These centering elements 5a, 5b or bevellings 4a, 4b are arranged and measured such that the abutting surfaces 7a, 7b of the top side plate 3 lying therebetween are each measured to be greater than the hole diameter 8 of the flow through 6 of the casting nozzle 1. It is thereby achieved that, during a change, the remaining molten steel in the base plate or the inlet nozzle above the top side plate 3, which has the same hole diameter, cannot flow between the casting nozzles 1, 10.

(14) At least the top side plate 3 is surrounded with a sheet jacket 9 which is designed as a metal glad or a cassette and advantageously extends all round the top side plate 3. This sheet jacket 9 could also include the tubular part 2 in the top part. The centering elements 5a, 5b are fixed, for example welded, onto the sheet jacket 9 as curved sheets or blocks. They are preferably dimensioned approximately the same as the plate thickness in order to reduce the load per surface. However, as with the sheet jacket 9, they are moved back slightly from the top sliding surface 3. The bevellings 4a, 4b are advantageously surrounded by the sheet jacket 9.

(15) According to FIG. 3, in the abutting surfaces 7a, 7b formed from the refractory material of the top side plate 3, the width 9 of a metallic sheet jacket 9 is reduced vis--vis the two other side surfaces, and the abutting surfaces 7a, 7b protrude vis--vis this sheet jacket 9 in the top sliding surface 3, and it is thus guaranteed that, during a change, the one abutting surface is always in tight contact with the other abutting surface of an adjacent casting nozzle. In this connection, care is to be taken that the dimensions of the centering elements 5a, 5b and of the bevellings 4a, 4b corresponding thereto are chosen such that they do not cause the abutting surfaces 7a, 7b to be spaced apart from one another during a change.

(16) The angles of inclination and may vary according to conditions. However, in any case they are intended to be dimensioned such that, during the changing process, the new casting nozzle cannot catch with the casting nozzle being replaced by becoming wedged. In principle, these angles of inclination can be approximately up to 80 or 10.

(17) FIG. 4 shows the above-mentioned casting nozzle 1 during a change, in which, for example, it is being pushed into the casting position in the place of a casting nozzle 10 located in this position.

(18) According to the invention, during a change, the casting nozzle 1 cooperates with its centering elements 5a, 5b with the bevellings 14a, 14b of the adjacent identically designed casting nozzle 10, and thus an approximately fixed guiding of the two casting nozzles results. The centering elements 5a, 5b with their contact surfaces are each provided with a similar angle of inclination , as the bevellings.

(19) The casting nozzles 1, 10 are replaced in particular by means of a changing device 20, which has known mechanical guiding means 21, lifting push means, preferably spring-loaded rockers 23, and a linear actuator with a push rod 24 and frontally a U-shaped shoe 22 with guide elements 22.

(20) To form the outflow for the molten material, a refractory inlet nozzle 25 is mounted in replaceable manner in the outlet of a metallurgical vessel and a bottom plate 26 of the changing device 20, through which the casting nozzle 1 can be positioned in casting position below the inlet nozzle 25, for a casting. In so doing, the guiding means 21 and the spring-loaded rockers 23 grip around the top side plates 3, 13 of the casting nozzles 1, 10 and press same against the sliding surface 25 of the inlet nozzle 25, wherein they can be displaced along these sliding surfaces. Conventionally, during a change, the casting nozzle 10 is pushed out and can then be removed from the ingot mould.

(21) Within the framework of the invention, the push rod 24 of the linear actuator of the changing device 20 is designed at the front side with the guide elements 22 which engage in the bevellings 4a, 4b of the casting nozzle 1 and push inwards along the plane of the plate, against the top side plate 3, with pushing forces K1, K2 indicated by the arrows. An additional guiding effect is thus achieved on the casting nozzles 1, when pushing in same as a new dipping tube and it can thus be inserted and centered with precision without wobbling or shaking movements of same.

(22) FIG. 5 shows a changing device 30 with so-called refractory metering nozzles 31, 32, where the plates are designed exactly according to the invention at the top side, but shorter nozzles 33, 33 are provided in the place of tubes, as in FIG. 1. For the same elements respectively parts of this changing device 30 are used the same reference numbers like in FIG. 4, which are therefore not anymore explained again. The mechanical guiding means 34, spring-loaded rockers 35, and a linear actuator with a push rod 24 and frontally a U-shaped shoe 22 with guide elements 22 are provided like with device of FIG. 4. These metering nozzles 31, 32 can be inserted and centered with precision without wobbling or shaking movements of same as well.

(23) The invention is explained sufficiently using the above embodiment example. It could, however, self-evidently be explained using other variants. To form the outflow for the molten material, a refractory base plate and/or an inlet nozzle is mounted in replaceable manner in the changing device, through which a casting nozzle can be positioned in casting position below the base plate or the inlet nozzle, for a casting. The centering elements in the plate could also be designed differently, such as for example as protruding bars or the like. The centering elements can be shaped symmetrically or asymmetrically.

(24) Principally the abutting surfaces could also be made with a simpler embodiment, where only this metallic sheet jacket 9 would be surrounding the plate 3 without these formed protruding refractory materials in the top sliding surface 3, what is not showed. The metallic sheet jacket 9 would extend at the abutting surfaces almost up to this top sliding surface 3.

(25) While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.