Casting plate and casting plate casing with detector-engaging protrusion

Abstract

Casting plates constructed for facing the casting orifice of a metallurgical vessel are provided with a metallic casing. The casting plates and metallic casing are provided with a protrusion configured to interact with a detector. The casing has a main surface with an opening, and two substantially longitudinal bearing surfaces. The protrusion extends from the casing in a direction substantially parallel to the longitudinal bearing surfaces. The protrusion is formed by a ramp having an inclined portion.

Claims

1. Metallic casing for encasing a refractory thus forming a casting plate, the metallic casing comprising: a main surface having a latitudinal dimension comprising an opening and side edges extending to said main surface and defining the perimeter thereof; two planar, substantially longitudinal bearing surfaces configured to slide along guiding rails, wherein the longitudinal dimension of the bearing surfaces comprises a plate sliding direction, and wherein each of the two bearing surfaces is disposed at a latitudinal extent of the main surface; a detector-engaging protrusion projecting from the main surface and extending in the plate sliding direction, the sliding direction being substantially parallel with the longitudinal bearing surfaces, and being located outside of and latitudinally adjacent to one of said bearing surfaces, said protrusion being formed by a ramp comprising an inclined portion, the inclination being in the plate sliding direction, wherein the protrusion comprises a portion parallel with the bearing surfaces, and wherein the ramp comprises an inclined portion extending from the main surface to the portion parallel with the bearing surfaces; wherein the casing comprises longitudinal bottom edges parallel with said longitudinal bearing surfaces, and wherein said protrusion projects from at least one of said longitudinal bottom edge, and the bearing surfaces are planar and not comprised in the same plane as the longitudinal bottom edges.

2. The casing of claim 1, wherein the protrusion is situated on only one side of the metallic casing.

3. The casing of claim 1, comprising two protrusions wherein each protrusion is situated on either side of the metallic casing, symmetrically in relation to a longitudinal axis of said casing.

4. The casing of claim 1, wherein, the casing comprises two pairs of opposed side edges as follows: two longitudinal edges and two transverse edges, wherein two segments respectively parallel to the transverse edges and the longitudinal edges of the casing and comprising the center of the opening divide the casing into four quadrants (1, 2, 3, 4); two quadrants (3, 4) extending from the opening center in one direction parallel to the sliding direction being larger than the two quadrants (1, 2) extending in the opposite direction from the opening center, and the casing further comprises a tubular portion matching and extending from the opening of the main surface.

5. The casing of claim 1, wherein the casing further comprises a tubular portion matching and extending from the opening of the main surface, wherein the tubular portion comprises a tubular opening, and wherein the protrusion is located adjacent the bearing surface, and outside or on longitudinal sides of a rectangle formed by transverse side edges of the casing and two tangents (A, B) to the tubular opening parallel to the longitudinal side edges of the casing.

6. A casting plate, comprising: a refractory comprising a sliding face and comprising a casting channel formed in the sliding face, and a metallic casing according to claim 1, the metallic casing encasing the refractory in the vicinity of the sliding face.

7. The casting plate of claim 6, wherein the protrusion projects away from the sliding face.

8. The casting plate of claim 6, further comprising a refractory tubular extension, to extend from the casting channel and away from the sliding face.

9. The casting plate of claim 7, wherein the protrusion is formed by a ramp comprised in a plane orthogonal to the sliding face and comprising an inclined portion.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) To explain the invention more clearly, an embodiment given as a non-limitative example of the scope of the invention will now be described, with reference to the appended figures wherein:

(2) FIGS. 1, 2, and 24 are sectional perspective views of a casting tube changer device for a tundish of a casting installation according to the invention,

(3) FIG. 3 is a top view of the frame of the device,

(4) FIG. 4 is a perspective bottom view of the device,

(5) FIGS. 5 and 5a are perspective views of a metallic casing of a casting plate according to the invention,

(6) FIG. 5b is a perspective view of another embodiment of the casing,

(7) FIGS. 6, 6a and 6b are bottom views of the metallic casing of FIG. 5,

(8) FIG. 7 is a sectional view of the casing of FIG. 6 along VII-VII,

(9) FIGS. 8 and 9 are sectional views along VIII-VIII (plane positioned in FIG. 6) of two alternative embodiments of metallic casings,

(10) FIGS. 10, 15, 17, 19 and 22 are perspective bottom views of the device at various phases along the plate displacement,

(11) FIGS. 11, 16, 18, 20, 21 and 23 are sectional views along XI-XI (plane position in FIG. 4) of the pusher rod and limit switch,

(12) FIGS. 12, 13, are sectional views of the machine along the planes XII-XII, or XIII-XIII in FIG. 3,

(13) FIG. 14 is a similar view of FIG. 12, illustrating the detection of the plate during its displacement.

DETAILED DESCRIPTION OF THE INVENTION

(14) The embodiment described herein is applicable to a casting installation distributor (or tundish) but could apply to any metallurgical vessel and particularly a casting ladle, as well as a distributor.

(15) The distributor, also called tundish, is used to distribute molten metal to one or a plurality of casting moulds, supplied by casting ladles successively pouring their content thereof into the distributor. For this purpose, the distributor may comprise a plurality of casting orifices, only one of which is taken into consideration in this case.

(16) The example illustrated by the figures relates to a casting plate comprising a tubular refractory extension, also referred to by those skilled in the art as “outer nozzles” or “casting tubes” but it could also apply to calibrated plates or nozzles not comprising tubular extensions or merely a slight tubular extension. In the context of the present invention, casting plates can be used to transfer the molten metal in the form either of a free flow with a short tube, or of a guided flow with a longer, partly submerged casting tube.

(17) FIG. 1, the device comprises a frame 1 comprising means for attachment to a metallurgical vessel such as a tundish (not shown), in the vicinity of an orifice of said vessel. An inner nozzle 2 is positioned in the frame. The inner nozzle comprises a lower portion in the form of a plate 2a and an upper tubular extension 2b, passing through the wall of the vessel (not shown). In the present description, the casting channel of the inner nozzle 2 is considered to be the casting orifice of the metallurgical vessel.

(18) The frame 1 comprises a housing 3 for receiving the plate 2a of the inner nozzle 2.

(19) The plate 2a, hereinafter referred to as the “top plate”, as opposed to that of the outer nozzle, described below, is held firmly in the housing 3 of the frame by known clamping means not described herein. The top plate is a fixed element during metal casting.

(20) The frame 1 bears a pusher 10 having a general cylindrical shape extending along a substantially horizontal axis (in the machine operating position), substantially orthogonal to the casting channel of the inner nozzle 2. This pusher 10 comprises a hollow cylindrical body 11 attached to the frame and a rod 12 suitable for sliding axially in the cylindrical body 11 under the action of a hydraulic jack 13 borne by one of the end of the body 11.

(21) The single-stroke hydraulic jack 13 controls the rod 12 in the axial translation movements thereof.

(22) Hydraulic connections (ducts or pipes, represented by the arrows A and B) supply the hydraulic jack 13 with pressurised fluid.

(23) The cylindrical body 11 comprises a longitudinal slot through which an arm 18, rigidly connected to the rod 12, projects from the cylindrical body 11, in the direction of the frame 1.

(24) The slot is rectilinear apart from at the end close to the jack, where it forms a gap, known per se, which gives the arm 18 an idle (resting) position wherein it is released upwards in relation to the working positions thereof.

(25) The length of the slot is substantially identical to the maximum stroke of the hydraulic jack 13, enabling the movement of the rod 12 and the arm 18 on the entire stroke.

(26) In FIG. 3, it can be seen that the arm 18 is arranged to push a casting tube 19, also referred to as an “outer nozzle” waiting in standby position next to another casting tube 20 which is in casting position. The pusher 10 is thus suitable for pushing a casting plate or tube from a standby station to an operating station.

(27) In FIG. 4, it is first of all noted that the plate 2a of the inner nozzle (the “top plate”), wedged in the housing 3 of the frame, is slightly raised in relation to the plane bottom face 22 of the frame.

(28) It is also noted that the top plate 2a has, about the casting orifice 23 thereof, a plane surface 24 (wherein a known gas injection groove (not shown) may be formed).

(29) Rails 21 are positioned facing the plane bottom face of the frame. The tubes 19, 20 are moved along the rails 21.

(30) On the trajectory of each rail 21, pressing means, usually springs combined with cams (not shown in the figures and known to those skilled in the art), are arranged to apply a thrust on the face of the plate of a tube 19, 20 inserted on the rails in the direction of the top plate 2a.

(31) Returning to FIG. 2, it can be seen that each casting tube 19, 20, comprises a plate 19a, 20a and a tubular section 19b, 20b extending from the casting channel to lateral outlets 19c, 20c through which the molten metal flows into an ingot mould (not shown).

(32) Each plate 19a, 20a comprises a sliding face 19d, 20d wherein the casting channel opens. Downstream from said channel (in relation to the tube sliding direction), the sliding face 19d, 20d is sufficiently large to form a sealing surface or shut-off surface 19e, 20e suitable for sealing (closing) the vessel casting orifice.

(33) A tube on the operating station may thus adopt a casting position, like the tube 20 in FIGS. 1 and 2, wherein the casting channel thereof is facing the vessel casting orifice, and a sealing position, like the tube 19 in FIG. 24, wherein the sealing surface 19e thereof is facing the vessel casting orifice.

(34) Each casting tube has a metallic casing 28 (also referred to as can by those skilled in the art) cladding the plate thereof, in a known manner.

(35) FIGS. 5 and 5a represent such a metallic casing 28 according to one embodiment of the invention. The metallic casing 28 is represented upright, i.e. in the orientation of the tubes 19, 20 represented in FIGS. 1, 2 and 24. The plate sliding direction is represented by the arrow.

(36) Generally speaking, the metallic casing 28 is similar to the metallic cans according to the prior art. In particular, it has an overall rectangular outline and comprises a main surface 50 comprising an opening and side edges extending to the main surface and defining the perimeter thereof and two longitudinal bearing surfaces 29 for sliding on the rails 21 of the device for guiding and for, in operation position, pressing up the bottom plate 19a, 20a against the top plate 2a.

(37) However, the metallic casing 28 of the present invention further comprises a protrusion 30 extending in the plate sliding direction, e.g. parallel with the longitudinal bearing surfaces 29, In the particular embodiment of FIGS. 5 and 5a, the casing comprises two protrusions, each protrusion 30 of the casing 28 projecting from longitudinal bottom edges 31, the edges 31 being parallel to the bearing surfaces 29. The bearing surfaces 29 and the edges 31 extend in the plate sliding direction represented by the arrow. The edges 31 are optional as the protrusion could project from the main surface 50.

(38) Each protrusion 30 is formed by a ramp comprising an inclined portion 30a and a portion 30b parallel with the bearing surface 29 or the longitudinal edges 31.

(39) In the alternative embodiments illustrated in FIGS. 8 and 9, the protrusions 30′ and 30″ have different profiles, but providing substantially the same effects. In FIG. 8, the protrusion 30′ has a profile obtained by tangent circular portion connection. In FIG. 9, the protrusion 30″ comprises four ramps connected by sharp angles.

(40) FIG. 5b represents an alternative embodiment, the casing comprises a pair of opposed side edges, one of which has a first thickness (a) and the second of which has a second thickness (b) greater than said first thickness (a). This way, the bearing surfaces 29 are spaced apart vertically from a distance (d). This provides a foolproof or safety system as the casting plate can only be introduced into the device in the correct orientation.

(41) Regardless of the profile thereof, each protrusion 30, 30′, 30″ is arranged to engage with a plate passage detector between the standby station and the operating station. In the example described, said detector takes the form of a pivoting lever 32 hinged on the machine frame 1, particularly seen in FIGS. 10, 12, 14, 15, 17, 19 and 22.

(42) So as to properly interact with the lever of the device, the protrusion has to be positioned in a specific area of the main surface, the area depending on the position of the lever 32 in the device.

(43) As illustrated in FIG. 6b, the casing 28 comprises two pairs of opposed side edges as follows: two longitudinal edges 56,57 and two transverse edges 54,55, the two segments respectively parallel to the transverse edges and the longitudinal edges of the casing 28 and comprising the centre 52 of the opening divide the casing into four quadrants (1, 2, 3, 4); two quadrants being larger (3, 4). The protrusion is located in the two larger quadrants (3, 4) for proper interaction with the lever 32.

(44) Similarly, the protrusion should be located outside of the bearing surfaces 29 to avoid a possible interaction of the protrusion with the rails and/or the pressing means of the device.

(45) As illustrated in FIG. 6a, a rectangle is formed by the transverse side edges 54, 55 of the casing and the two tangents (A, B) to the tubular opening which are parallel to the longitudinal side edges 56,57. In certain embodiments, the protrusion is located on the longitudinal sides of the rectangle (A, B) or outside of the rectangle. The opening of the casing 28 is intended to receive the refractory tubular extension (19b,20b) of the casting plate 19,20. It is thus preferable that the passage for displacing the casting tube remains free to avoid a possible interaction of the lever with the refractory tubular extension (19b,20b). In FIG. 6a, the protrusion is located between the bearing surfaces 29 and the tangents (A, B). However the protrusion could be located on the tangents A or B as long as there is no interaction of the plate passage detector 32 with the refractory tubular extension 19b, 20b.

(46) As can be seen in the sectional view in FIG. 12, the pivoting axis 33 of the lever 32 is parallel with the axis of the jack 13 and the rod 12. When pivoting, the lever may adopt a first so-called unlocked position, illustrated by FIG. 12, and a second so-called locked position, illustrated by FIG. 14.

(47) In more detail, the lever 32 comprises one detection end 34 leaving the passage free for the edge 31 of the casing 28 when the bottom plate slides on the rails 21, regardless of the position of the lever. On the other hand, when the bottom plate slides on the rails 21 between the standby station and the operating station, the lever detection end situated in the unlocked position meets the protrusion 30 of the metallic casing. In this way, by means of the inclined portion 30a thereof, the protrusion 30 causes the lever to change from the unlocked position in FIG. 12 to the locked position in FIG. 14.

(48) The lever 32 comprises, opposite the detection end 34 thereof, a ball joint 35 inserted into a slot 36 of an abutment 37 movable by translation in a flue 38 perpendicular to the axis of the rod 12 and the jack 13 and opening into the cylindrical body 11.

(49) In the unlocked position of the lever, as in FIG. 12, the movable abutment 37 is in the vicinity of the rod 12, but does not intercept the cross-section thereof. In this “sealing” (shut-off) position, the movable abutment 37 does not block (impede) the axial translation movements of the rod. The rod 12 can thus move along the entire stroke of the jack 13, referred to as the “long stroke”, necessary to move a tube to the sealing position on the operating station.

(50) In the locked position of the lever, illustrated in FIG. 14, the movable abutment enters a recess 39 provided for this purpose on the rod 12 and holds said rod in a range of positions wherein the recess 39 is facing the movable abutment 37. In this “replacement” or “casting” position, the movable abutment 37 limits the stroke of the rod 12.

(51) As seen in FIG. 16, the recess 39 is defined asymmetrically: on the side of the jack 13, a plane shoulder 40 perpendicular to the rod axis forms a bearing surface, whereas, opposite the jack 13, a bevel 41 is present.

(52) This asymmetry offers the following effects.

(53) If the movable abutment 37 is in the “replacement” or “casting” position (FIGS. 14 and 16), the movement of the rod 12 in the opposite direction of the jack 13 causes the shoulder 40 to press against the movable abutment 37, blocking the progression of the rod 12 without tending to return the movable abutment 37 to the sealing position, i.e. without tending to return the lever to the unlocked position, given that the force applied by the rod on the movable abutment 37 has no radial component. Although it is theoretically not necessary to hold the lever in the locked position to ensure the blocking of the rod, otherwise to prevent it from collapsing under its own weight, a ball spring 42 acts as a stabiliser, holding the movable abutment, and thus the lever, in each of the two positions thereof (replacement or casting position and sealing position), by entering hollows 43 formed in the face of the movable abutment 37 facing the ball spring 42.

(54) In this replacement position, the movable abutment 37 limits the stroke of the rod to a “short stroke”, necessary to move a casting tube to the casting position on the operating station.

(55) During a movement of the rod 12 in the opposite direction, i.e. in the direction of the jack 13, the movable abutment 37 comes into contact with the bevel 41 and the force applied by the rod on the movable abutment 37 comprises a radial component tending to move the lever to the unlocked position. As soon as this force is greater than the resistance opposed by the ball spring 42, the movable abutment 37 and the lever 32 move to the unlocked position, freeing the passage for the rod, as illustrated in FIG. 20.

(56) To summarize, the pusher 10 is provided with means for moving selectively forwards along two strokes, said means consisting of the pivoting lever 32 and the movable abutment 37, combined with the rod 12 provided with the recess 39 thereof. The two pusher strokes are: a short stroke (FIG. 18) pushing a casting tube to the casting position on the operating station, and a long stroke (FIG. 23) pushing a casting tube to the sealing position on the operating station.

(57) The movable abutment 37 and the corresponding recess 39 on the rod 12 thus form a limit switch according to the invention and the pivoting lever 32 forms a tube passage detector from the standby station to the operating station.

(58) The operation of the device during a tube replacement operation and an emergency casting stop operation will now be described.

(59) The device described above contains means forming a device for holding and replacing a casting tube 20 facing a casting orifice of a distributor of a continuous molten metal casting installation.

(60) During continuous molten metal casting, the casting tube 20 and the inner nozzle 2 are positioned in mutual alignment, as represented in FIGS. 1 and 2.

(61) The pivoting lever 32 is in the unlocked position and the movable abutment 37 in the sealing position.

(62) The arm 18 is initially situated in the idle position thereof, inside a gap of the slot, as represented in FIG. 1.

(63) When the time to replace the casting tube 20 approaches, a replacement casting tube 19 is positioned on the standby station, at the entry of the rails 21, in the vicinity of the casting tube 19 currently in use, as represented in FIG. 3.

(64) To replace the tube 20, the jack 13 is actuated to move the rod 12 forwards.

(65) The arm 18 then leaves the gap and is aligned with the plates 19a and 20a, and moves forwards in the direction thereof.

(66) The arm 18 then comes into contact with the plate 19a and the casting tube 19 starts moving in translation on the rails 21.

(67) When the casting tube 19 is about to reach the operating position thereof, the protrusion 30 of the metallic casing pushes the pivoting lever 32 back to the locked position, moving the movable abutment 37 in the direction indicated by the arrow in FIG. 16, to move said abutment to the replacement position wherein it enters the recess 39 of the rod, said recess facing, at that time, the flue 38. The arm 18, the casting tube 19 and the rod 12 continue to move forwards under the action of the jack 13 until the shoulder 40 of the rod presses against the movable abutment 37, blocking the rod, as illustrated in FIG. 18. At that time, the casting tube 19 has reached the casting position thereof on the operating station. The pusher or drive has thus moved along the short stroke thereof without needing to control the jack specifically.

(68) The jack 13 then returns the rod and the arm to the initial idle position thereof. The lever 32 returns to the unlocked position by means of the bevel 41 pushing the movable abutment 37 to the sealing position, as seen in FIGS. 19, 20 and 21.

(69) With the casting tube 20 in the casting position, as illustrated in FIGS. 1 and 2, it may also be necessary in case of emergency to discontinue (interrupt) molten metal casting and it may not be possible to do so using other means inside the distributor.

(70) In this case, the jack 13 is actuated as described above, causing the arm 18 to move forwards. Given that the movable abutment 37 is situated and remains in the sealing position, i.e. outside the straight section of the rod 12, the rod 12 can move along the entire jack stroke, as illustrated in FIG. 23. The pusher 10 thus moves along the long stroke thereof, pushing the casting tube 19 to the sealing position, as illustrated in FIGS. 22 and 24.

(71) This way, an actuation of the jack causing the emergency interruption of the casting is obtained without needing to control the jack specifically.

(72) Finally, in the scenario whereby a casting tube is in reserve on the standby station when an emergency sealing of the casting orifice is required, the jack is actuated a first time to move the replacement casting tube to the casting position of the operating station, as described above, then the jack is allowed to move back along a slightly greater length than that of the recess of the rod so as to return the lever to the unlocked position, as illustrated in FIG. 20, and the jack is re-actuated again to move forwards: the rod can then move to the position in FIGS. 22 and 24 to push the casting tube to the sealing position, i.e. in the position wherein the sealing surface 19e thereof is facing the vessel casting orifice.

(73) Numerous modifications and variations of the present invention are possible. It is, therefore, to be understood that within the scope of the following claims, the invention may be practiced otherwise than as specifically described.