Title of Invention

VALVE PLATE FOR A SLIDING GATE VALVE AT THE OUTLET OF A VESSEL CONTAINING MOLTEN METAL

Abstract

Title: Valve plate for a sliding gate valve at the outlet of a vessel containing molten metal. This invention relates to valve plate for a sliding gate valve at the outlet of a vessel containing molten metal comprising a refractory plate (22), a metal shell (21) surrounding it and having centering device which is so constructed that the valve plate (20) is loosely inseertable into a metal frame of the sliding gate valve and is centred therein, at least in one direction, characterized in that the centering device is constituted by preferably two abutment surfaces (23, 24) which rise up substantially at least partially vertically towards the plate support (26) afforded by the metal shell (21) and have a thickness for example the same as the metal shell thickness (21'), these abutment surfaces (23, 24) being so arranged that, in the inserted and centred state of the plate (20), they engage correspondingly shaped abutment surfaces (18', 19') on the metal frame (14, 15).

Full Text

1A The invention relates to a valve plate for a sliding gate valve at the outlet of a vessel containing molten metal having a refractory plate, a metal shell surrounding it and comprising centering device which is constructed that the valve plate may be inserted loosely in a metal frame of the sliding gate valve and is centred therein, at least in the direction of movement; and to a sliding gate valve therefor. In the known sliding nozzle plate disclosed in the publication DE-A-4433356, the metal housing, which surrounds the plate from below and laterally, has one or a number of projections which fit into corresponding recesses in the metal frame. In the inserted state state of the plate its projections are retained with a lateral clearance in the range between 0.1 and lmm in the direction of movement of the plate. These projection mush therefore be provided with a very narrow tolerance and are correspondingly expensive to produce. Against this background, it is the object of the present invention to provide a valve plate of the type mentioned above which, with precise centering in the metal frame, may be manufactured simply and economically. This valve plate is also to be so dimensioned that the space requirement when such plates are stacked is thereby maintained at a minimum and the risk of damage of this centering device can be eliminated to the greatest extent possible. This object is solved in accordance with the invention if the centering device is.... 2 constituted by preferably two abutment surfaces which rise up substantially at least partially vertically towards the plate support afforded by the metal shell and have a thickness for example the same as the metal shell thickness, these abutment surfaces being so arranged that, in the inserted and centred state of the plate, they engaged correspondingly shaped abutment surfaces on the metal frame. This valve plate may be manufactured simply with its construction in accordance with the invention and such a centering in a metal frame of the sliding gate valve is, however, nevertheless ensured with it that it can be used in an extremely operationally secure manner. Exemplary embodiments and further advantages of the invention will be explained in more detail with reference to the accompanying drawings, in which: Fig. 1 is a longitudinal sectional view of a sliding gate valve illustrated in part with valve plates in accordance with the invention, Fig. 2 is a longitudinal sectional view of the portion II of the valve plate in Fig. 1, Fig. 3 is a plan view of the valve plate on the line III-III in Fig. 1, Fig. 3A is a cross-sectional view of the valve plate on the line A-A in Fig.3, Fig. 4 to are longitudinal sectional views showing respective Fig 9 modifications of a valve plate in accordance with the invention, 3 Fig. 10 is a plan view of a valve plate modification, and Fig. 10A is a longitudinal sectional view of the valve plate of Fig. 10. Fig. 1 shows a portion of a sliding gate valve 10 at the outlet of a vessel containing molten metal, only the outer steel shell 13 and a refractory sleeve brick 17 of the vessel being shown. This vessel is preferably a ladle, which may be filled with molten steel, for a continuous casting installation. A refractory sleeve 11 defines the discharge opening 12 from this vessel. Closely adjoining this sleeve 11 is an upper valve plate 20, which is secured in the metal frame 14 of the sliding gate valve 10 and which cooperates with a movable valve plate 20 disposed beneath it. The lower valve plate 20 serves to open and close the valve 10 and it is mounted for this purpose in a longitudinally movable slider unit constructed as a metal frame 15 in which a refractory discharge sleeve 16 adjoining the plate 20 is also mounted. This sliding gate valve 10 is constructed in a conventional manner and will therefore not be described in more detail below. The valve plates 20 have a respective prefabricated, commonly deep drawn, stamped metal shell 21 and a plate 22 comprising a refractory ceramic material mortared into it. The mortar 28 is introduced into the metal shell 21 in a plastic state and after the insertion of the refractory plate it dries and holds the latter firmly therein. This plate 20, which is separately fabricated as a unit, is then loosely inserted in its entirety into the metal frame 14, 15 and it is held therein, at least in the direction of movement, by centering means. 4 As shown in Fig. 2 and Fig. 3, centering means are associated with the valve plate 20 which, in accordance with the invention, is constituted by preferably two abutment surfaces 23, 24 disposed at a defined spacing from one another. As shown in Fig. 2, these abutment surfaces 23, 24 rise up approximately vertically to the plate support 26 constituted by the metal shell 21 and they are each provided with a height approximately the same as the metal shell thickness 21'. In the inserted and centred state of the plate 20, these abutment surfaces 23, 24 engage correspondingly shaped abutment surfaces 18', 19' on the metal frame 14, 15 so that the plate 20 is held therein loosely and substantially clearance-free in the direction of movement. For this purpose, the metal frame 14, 15 has projecting noses 18, 19 with respective abutment surfaces 18', 19'. These cooperating abutment surfaces 18', 19' and 23, 24 are constructed as perpendicular surfaces with respect to the plate support surface 26. They could also be somewhat dished or provided with a chamfer for simpler insertion of the plate into the frame. In a very advantageous construction the metal shell 21 is provided with discontinuities and respective inwardly bent ribs 21' at them to define the abutment surfaces 23, 24. The edge produced in the metal shell 21 with this discontinuity accordingly defines the corresponding abutment surface 23, 24 which is exposed by the rib 21". This rib 21" with the corresponding discontinuity may be fabricated in one working step by reason of the metal shell 21, which is produced by deep drawing. The tool mould accommodating the metal shell and the die are so constructed that whilst the die is forced into the tool mould the metal shell is deep drawn in trough shape and is severed at the said position. The abutment surface 23, 24 produced with this deep drawing process can be provided with a precise dimensional tolerance in the tenths of a 5 millimetre range without special post-machining. Such a valve plate may thus be equipped with this centering means described above in a very simple manner. As shown in Fig. 3, these two straight, elongate abutment surfaces 23, 24 extend on the rear surface of the plate at right angles to the longitudinal axis 21A of the plate. They are disposed at the same distance from the discharge opening 12 and provided with a length approximately equal to half the breadth of the plate and are so dimensioned that the pressure forces produced in the operating state on the abutment surfaces 23, 24 of the metal shell 21 are absorbed without deformation. Fig. 3A is a scrap sectional view of the centering of the plate in the metallic frame 15 transverse to the longitudinal axis 21A of the plate. It may be seen that the rib 21" is formed at a uniform spacing from the plate support 26 and the refractory plate 22 engages this rib 21", preferably on its inner surface. In addition to a parallel alignment, this makes possible a defined distance between the refractory plate 22 and the support 26. Furthermore, the nose 19 on the metal frame and the rib 21" are each provided with such a length that the rib 21" is arranged on both sides with its ends 27 with little clearance from the outer surface 28 of the nose 19 in the inserted state of the plate so that the plate 20 is also centred to a certain extent transversely to the longitudinal axis 21A of the plate. The valve plates of the exemplary embodiments described below and shown in Fig. 4 to Fig. 10 are constructed similarly to the plate 20 described in detail above. Only the differences or their specific constructions will therefore be 6 explained below. The refractory plates 22 are preferably each mortared into the sheet metal shell. Fig. 4 shows a valve plate 40 with centering means in accordance with the invention in which the two abutment surfaces 43, 44 are defined next to one another by a strip-shaped, inwardly bent rib 41' on the metal shell 41. This rib 41 * is defined laterally by two discontinuities in the metal shell 41 and arranged on one side of the plate support surface. The metal frame 15 for its part has a correspondingly constructed rectangular nose 36 on which respective abutment surfaces are present laterally which correspond to those on the plate 40. The valve plate 50 shown in Fig. 5 differs from the plate 20, which is shown in detail in Fig. 2 and Fig. 3, only in that discontinuities are not provided at the ribs 51'" to define the abutment surfaces 53, 54 but they are instead impressed in the manner of grooves into the metal shell 51. Fig. 6 shows a valve plate 60 with a metal shell 61 in which, in order to define abutment surfaces 63, 64, two ribs 61" are provided in a manner analogous to that in Fig. 2, but with the difference that both ribs 61" on the longer side of the support surface are arranged parallel to one another. Fig. 7 shows a valve plate 70 in which the centering means in accordance with the invention is again constructed as ribs 71" provided in a metal shell 71, as illustrated in Fig. 3, these ribs projecting, however, away from the plate 22. The abutment surfaces 73, 74 are correspondingly afforded by the end surfaces on the ribs 71" whilst the abutment surfaces on the metal frame are afforded by elongate grooves 79 formed in it. 7 Fig. 8 shows a valve plate 80 which is provided with abutment surfaces 83, 84 and which differs from that shown in Fig. 7 merely in that its refractory plate 82 is provided with tooth-shaped thickened portions 82' which project into the recesses in the metal shell 81 formed by bending away the ribs. In a valve plate 90 shown in Fig. 9, the abutment surfaces 93, 94 are afforded by a metal strip 95 which is secured, particularly spot welded, to the underside of the metal shell 91. This metal strip 95 is preferably of rectangular shape and the lateral edges on it, which serve as the abutment surfaces 93, 94, are arranged at right angles to the longitudinal axis of the plate 90. Fig. 10 and Fig. 10A show a further construction of a valve plate 100 in which the abutment surfaces 103, 104 have downwardly bent ribs 101', 103'. These abutment surfaces 103, 104 are distinguished by their circular shape, whereby the circle defined by them is concentric with the discharge opening in the plate and it is hereby ensured that this opening is precisely centred in the metal frame of the sliding gate valve and thus the openings in the two valve plates are arranged concentrically with one another. On the side of the plate with the smaller engagement surface there are two ribs 103' arranged symmetrically with respect to the longitudinal axis of the plate whilst on the opposite side a rib 101' is included in the metal shell 101. These abutment surfaces could of course be provided with a different shape instead of being of straight line or circular shape. These abutment surfaces provided on the underside of. the plate are advantageously formed directly on the metal shell for the purpose of simple 8 manufacture. In principle, they could, however, also be provided directly on the refractory plate 22, particularly if the refractory plate 22 were to rest in a known manner directly on the metal frame 15 and no metal shell were provided between them but only a band laterally surrounding the plate. The abutment surfaces would then be included directly in the refractory plate 22, in particular by virtue of one or two recesses on the underside of the refractory plate 22. 9 WE CLAIM 1. Valve plate for a sliding gate valve at the outlet of a vessel containing molten metal comprising a refractory plate (22), a metal shell (21) surrounding it and having centering device which is so constructed that the valve plate (20) is loosely insertable into a metal frame of the sliding gate valve and is centred therein, at least in one direction, characterised in that the centering device is constituted by preferably two abutment surfaces (23, 24) which rise up substantially at least partially vertically towards the plate support (26) afforded by the metal shell (21) and have a thickness for example the same as the metal shell thickness (21) these abutment surfaces (23, 24) being so arranged that, in the inserted and centred state of the plate (20), they engage correspondingly shaped abutment surfaces (18', 19') on the metal frame (14, 15). 2. Valve plate as claimed in claim 1, wherein the elongate abutment surfaces (23, 24), which extend on the underside of trie plate (20) transverse to its longitudinal axis (21 A) are provided with a length substantially equal to half the breadth of the plate so that the force produced in the operational state on the abutment surfaces (23, 24) can be absorbed without deformation of the metal shell. 2. 10 \. Valve plate as claimed in claim 1 or 2, wherein formed in the metal shell (21, 41, 61) there is a respective discontinuity and a rib (21", 41', 61") bent inwardly out of the plate (20, 40, 60) as it, whereby the abutment surfaces (23, 24) are provided by the discontinuities on the metal shell (21, 41, 61). 4. Valve plate as claimed in claim 3, wherein the refractory plate (22) engages the ribs (21", 41', 61") bent inwardly out of the plate (20, 40, 60). 5. Valve plate as claimed in claim 1 and 2, wherein formed in the metal shell (71, 101) there is a respective discontinuity and a rib (71", 101) at it projecting away from the plate (70, 100), whereby each abutment surface (73, 74; 103, 104) is provided at the end of the respective rib (71", 101). 6. Valve plate as claimed in claim 1, wherein one abutment surface (23, 24; 73, 74) is formed on one side of the discharge opening (12) whilst the other is formed on the opposite side of the discharge opening (12) on the plate support (26). 7. Valve plate as claimed in one of the preceding claims, wherein the ribs (21", 71") are so dimensioned with respect 7. 11 to the nose (19) or to the elongate grooves (79) in the metal frame (16) that the plate (20, 70) is centred not only in the direction of its longitudinal axis (21 A) but also transversely thereto. 8. Valve plate as claimed in claim 1 or 2, wherein the abutment surfaces (93, 94) are formed on end edges of at least one metal strip (95) secured to the metal shell (91) on the side of the plate support (26). 9. Sliding gate valve having at least one metal frame (14, 15) for accommodating a respective valve plate (20) as claimed in one of the preceding claims, wherein the metal frame (14, 15) is provided with abutment surfaces (18', 19') on which the plate (20) is centred, in the inserted state, at least in the direction of movement of the metal frame. 10. Sliding gate valve as claimed in claim 9, wherein the abutment surfaces (18', 19') are defined on the metal frame (14, 15) either on projecting noses (18, 19) or in elongate grooves (79). Title: Valve plate for a sliding gate valve at the outlet of a vessel containing molten metal. This invention relates to valve plate for a sliding gate valve at the outlet of a vessel containing molten metal comprising a refractory plate (22), a metal shell (21) surrounding it and having centering device which is so constructed that the valve plate (20) is loosely inseertable into a metal frame of the sliding gate valve and is centred therein, at least in one direction, characterized in that the centering device is constituted by preferably two abutment surfaces (23, 24) which rise up substantially at least partially vertically towards the plate support (26) afforded by the metal shell (21) and have a thickness for example the same as the metal shell thickness (21'), these abutment surfaces (23, 24) being so arranged that, in the inserted and centred state of the plate (20), they engage correspondingly shaped abutment surfaces (18', 19') on the metal frame (14, 15).

Documents:

00209-cal-1999 abstract.pdf

00209-cal-1999 claims.pdf

00209-cal-1999 correspondence.pdf

00209-cal-1999 description(complete).pdf

00209-cal-1999 drawings.pdf

00209-cal-1999 form-1.pdf

00209-cal-1999 form-2.pdf

00209-cal-1999 form-3.pdf

00209-cal-1999 pa.pdf

209-CAL-1999-(07-02-2012)-FORM-27.pdf

209-CAL-1999-FORM 27.pdf

209-cal-1999-granted-abstract.pdf

209-cal-1999-granted-claims.pdf

209-cal-1999-granted-correspondence.pdf

209-cal-1999-granted-description (complete).pdf

209-cal-1999-granted-drawings.pdf

209-cal-1999-granted-examination report.pdf

209-cal-1999-granted-form 1.pdf

209-cal-1999-granted-form 2.pdf

209-cal-1999-granted-form 3.pdf

209-cal-1999-granted-letter patent.pdf

209-cal-1999-granted-pa.pdf

209-cal-1999-granted-reply to examination report.pdf

209-cal-1999-granted-specification.pdf