Abstract:
Slide closure for a vessel containing molten metal includes a slide housing and a slide unit that can be displaced longitudinally towards the slide housing, at least one refractory closure plate can respectively be inserted into the slide housing. The closure plates can be pressed against one another by the slide unit being braced against the slide housing. The closure plates can respectively be fixed or centered therein by a placement device having a displaceable positioning element. These placement devices are respectively designed such that upon bracing the slide unit against the slide housing, placing of the positioning element and clamping or centering of the respective closure plate is brought about therein. Therefore, despite easier operation, increased operating reliability is guaranteed because the closure plates are clamped and centered mechanically.

Description:
FIELD OF THE INVENTION 
     The invention relates to a slide closure for a vessel containing molten metal that includes a slide housing, and a slide unit that can be displaced longitudinally towards the slide housing, wherein a refractory closure plate is insertable into the slide housing and/or slide unit and when two are present, are operatively pressed against one another by the slide unit being braced against the slide housing. The invention also relates to a method for placing closure plates in the slide closure for a vessel containing molten metal wherein a longitudinally displaceable slide unit is braced against a slide housing by means of a drive, wherein a respective refractory closure plate is inserted into the slide housing and slide unit. The refractory closure plates are pressed against one another. 
     BACKGROUND OF THE INVENTION 
     It is well known that the refractory closure plates in a slide closure have to be changed frequently because they are subjected to a high degree of wear due to the molten metal flowing through the latter when pouring. For this reason the slide closure has to be opened and closed again frequently, and this is labour-intensive. 
     In a slide closure according to publication WO-A-2004/069448 there is provided a clamping device for a refractory plate in which three of the clamping elements are in the form of clamping shoes mounted pivotably in the slide housing, and the fourth clamping element has a clamping jaw that can be adjusted in the direction of the corresponding closure plate side surface and which is mounted flexibly in the slide housing and is guided displaceably by a bracing means towards the side surface. This clamping jaw is arranged adjustably in a base body fixed securely in the housing, there being provided for its adjustment a rotatably adjustable eccentric the axis of rotation of which runs transversely to the direction of adjustment of the clamping jaw. Therefore, the closure plates have to be braced manually. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     The object underlying the present invention is to improve a slide closure such that replacement of the refractory closure plates in the slide housing or in the slide unit can also take place efficiently with assumed fixing and centring of the latter. 
     The object is achieved according to the invention by a slide closure including a placement device positioned within the slide housing or within the slide unit and each of which is designed such that upon bracing the slide unit against the slide housing, placement of the positioning element, and clamping or centering of the respective closure plate is obtained. In a method, the slide unit is braced against the slide housing by means of the drive and only after this bracing are the closure plates either clamped or centered within the slide housing or within the slide unit. 
     By means of this design according to the invention of the respective placement device within the slide housing or in the slide unit in which, by bracing the slide unit against the slide housing, as it were, placing of the positioning element and so clamping and centring of the respective closure plate is brought about therein, the closure plates on the ladle seat can be easily placed therein or be inserted into the slide housing, and after pivoting the slide unit against the slide housing automatic clamping or centring of the closure plates takes place. 
     Therefore, despite easier operation, increased operating reliability is guaranteed because the closure plates are clamped and centred mechanically and so no mis-manipulations, as can take place when clamping manually, can occur. 
     In the method according to the invention wherein initially the slide unit is braced against the slide housing and only then are the closure plates clamped and centred therein, it is advantageous that the closure plates rest correctly within the slide unit or within the slide housing and so no tilting of the latter occurs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       One exemplary embodiment of the invention and further advantages of the latter are described in more detail below by means of the drawings. These show as follows: 
         FIG. 1  is a slide closure according to the invention in a pivoted open open position, illustrated perspectively; 
         FIG. 2  is a perspective view of part of the slide unit according to  FIG. 1 ; 
         FIG. 3  is a perspective view of the placement device according to  FIG. 2  shown in the non-braced position, with a longitudinal section of its housing; 
         FIG. 4  a perspective view of the placement device similar to  FIG. 3 ; 
         FIG. 5  is a perspective view of the placement device according to  FIG. 2  in the clamping position, with a longitudinal section of its housing; and 
         FIG. 6  is a perspective view of the placement device similar to  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a slide closure  10  which can be mounted on a spout of a vessel (not detailed). The vessel is in particular a ladle of a continuous casting line containing molten steel. Needless to say, however, a tundish, a converter vessel or similar can also be provided. 
     The slide closure  10  is provided with a slide housing  11  and a slide unit  12  that can be displaced longitudinally towards the latter, in which a refractory closure plate  13 ,  14  can respectively be inserted. The slide unit  12  is held pivotably by means of hinges  16  attached to the side of the slide housing  11 . If the slide unit  12  is now pivoted towards the slide housing  11 , the sliding surfaces of the inserted closure plates  13 ,  14  come into contact with one another. 
     The closure plates  13 ,  14  can respectively be fixed or centered by means of a placement device  30  having a displaceable positioning element  33 , i.e., they can thereby be clamped in the slide housing  11  or in the slide unit  12  as required or be centered therein with hardly any play. 
     Fastened to the outside of the slide housing  11  are four supports  19  with inwardly directed guide rollers  21  which are intended to engage in corresponding longitudinal grooves  22  on the slide unit  12  when the latter is pivoted towards the slide housing  11 , and these two are braced against one another. These guide rollers  21  are then guided in these longitudinal grooves  22  on inside guide tracks  23  and are pressed against the slide housing  11  by spring components of the frames  18  contained in these supports  19 . 
     In a way known in its own right the guide tracks  23  are interrupted by corresponding recesses  24  by means of which the guide rollers  21  can be pushed into the longitudinal grooves  22 , and in addition, for each guide roller  21 , they are each provided with an obliquely extending ramp. When the guide rollers are introduced into these recesses  24  the slide unit  12  is displaced via the drive coupled to it into a position lying outside of the open and the closed position and the guide rollers  21  slide along these ramps by means of which the spring components are clamped and so the slide unit is braced against the slide housing, upon releasing, this slide unit being displaced in the opposite direction. 
     In the braced state of the slide closure  10 , the slide unit  12  with the slide  15  is moved to and fro by means of a drive (not detailed), and so the slide closure  10  is fully opened and restricted or closed, depending on the position of the flow-through openings of the closure plates  13 ,  14  in relation to one another. 
     According to the invention, this placement device  30  positioned within the slide housing  11  or within the slide unit  12  is designed such that upon bracing the slide unit  12  against the slide housing  11 , placement, as it were, of the respective positioning element  33  and so clamping and centering of the respective closure plate  13 ,  14  within the slide housing or the slide unit  12  is brought about. 
     The invention is characterized by this automatic clamping and centering of the closure plates by means of which the closure plates are only inserted into the slide housing and slide unit and no additional manual action has to be taken. 
       FIG. 2  shows the slide unit  12  with the opening  15 ′ holding the closure plate  14  and the inserted placement device  30  with the projecting cams  38 ′,  39 ′ arranged opposite and guide tracks  38 ,  39  formed on the latter. The respective placement device  30  can be inserted with its housing  35  as a replaceable clamping and placement module in the slide unit or in the slide housing. It is inserted almost with form closure in a recess in the slide unit  12  and is fixed automatically therein by the positioning element  33  being held in a corresponding widening groove by means of a cam  43 ′ by axially displacement into the bracing or centring position with its longitudinal part  43  projecting on the other end of the housing  35 . 
     The guide tracks  38 ,  39  formed on the slide unit  15  co-operate with the carrier element or the locking means of the placement device  30  in the slide housing  11  and conversely the guide tracks in the slide housing  11  co-operate with the carrier element or the locking means of the placement device in the slide unit (not detailed). 
     This placement device  30  with the positioning element  33  clamps the respective closure plate  13 ,  14  against preferably three respective fixed stop surfaces in openings  15 ′ in the slide housing  11  or in the slide unit  15 . 
     It is evident from  FIG. 3  to  FIG. 6  that each respective placement device  30  comprises a housing  35 , the positioning element  33  displaceable transversely within the housing  35 , a last clamping component  32  displaceable into the clamping and placement position, a carrier element  31  guided in a groove  36 ,  36 ′ in the housing  35  and a locking means  37  guided in the groove  36 ,  36 ; and the guide tracks  38 ,  39  on the cams  38 ′,  39 ′ co-operating with the carrier element  31  and the locking means  37 . 
     In the placement device  30  a longitudinal part  43  is guided axially within the housing  35  and the positioning element  33  connected operatively to the latter is guided with transverse displacement. In addition, this carrier element  31  and the locking means  37  are held against this longitudinal part  43 . The clamping component  32  in the form of a compression spring rests on the face side against one end of the housing  35  and on the other end against this locking means  37 . The carrier element  31  guided in this groove  36 ,  36 ′ is disposed projecting towards the housing  35  and is in contact with the guide tracks  38 ,  39  of the cams  38 ′,  39 ′ projecting on the slide housing depending on the position of the slide unit  12  in relation to the slide housing  11 . 
     These guide tracks  38 ,  39  formed on the projecting cams  38 ′,  39 ′ on the slide unit  12  or on the slide housing  11  are arranged such that on the one hand the positioning element  33  is placed on the corresponding closure plate  13 ,  14  by displacing the slide unit or is released from the latter. 
     In  FIG. 3  and  FIG. 4  the positioning element  33  is illustrated in the withdrawn position in which a closure plate can be inserted, for example, into the opening  15 ′ of the slide unit  12 . Here the locking means  37  is in the locked position in which the longitudinal part  43 , the clamping component  32  and also the carrier element  31  are also in the withdrawn position. 
     By displacing the slide unit  12  pivoted towards the slide housing  11  the housing  35  moves with the latter in the axial direction of the longitudinal part. With its guide track  38  the cam  38 ′ on the slide housing  11  indicated in  FIG. 4  causes the carrier element  31  to be pushed into the axially extending groove  36  in this oblique groove  36 ′ and so also causes the locking means  37  to be moved into this oblique groove  36 . This brings about release of this locking and consequently the carrier element, the locking means, the longitudinal part and the positioning element are moved by the clamping component  32  into the position according to  FIG. 5  or  FIG. 6 . The positioning element  33  is pushed outwards by a corresponding oblique surface  34  on the longitudinal part  43  so that self-retention is achieved between the latter and so release is prevented in the operating state. 
     In this clamping and placement position of the placement device  30  according to  FIG. 5  and  FIG. 6  the housing  35  is conversely in turn moved with the slide unit  12  in the axial direction of the long part when said slide unit  12  is released. With its guide track  39 , the cam  39 ′ on the slide housing  11  indicated in  FIG. 6  causes the carrier element  31  and the aforementioned parts associated with it to be brought along the axially extending groove  36  into this oblique groove  36 ′ by the axial movement of the housing  35  and so the locking means  37  is moved back into the locking position according to  FIG. 4 . 
     In the method according to the invention, the slide unit  12  is pivoted out of the open position illustrated in  FIG. 1  onto the slide housing  11  and is then braced against the slide housing  11  by means of the drive, as described in more detail above. Only after this bracing are the closure plates  13 ,  14  in the slide housing  11  or in the slide unit  12  either clamped or centered by this respective placement device  30 . 
     One is thus offered the further advantage that the closure plates lie correctly in the openings  15 ′ in the slide unit  12  or in the slide housing  11  due to this bracing, and so there is no tilting of the latter, this being a disadvantage with the conventional manual assembly of closure plates. 
     For this purpose the clamping and placement module and the cams  38 ′,  39 ′ of the placement device  30  are positioned in relation to the inside guide tracks  23  and the ramps or the guide rollers in the slide unit  12  or in the slide housing  11  in the direction of displacement of the slide unit such that first of all the guide rollers  21  slide over the ramps and only then does the respective cam  38 ′ trigger this adjustment of the carrier element  31  and, as it were, of the other parts. 
     The invention could of course also be illustrated by other embodiments. Thus, with this placement device, the positioning element could be placed such that it is not clamping, but simply centering of the respective closure plate that is brought about. The positioning element would be adjusted to such an extent here that it does not brace the respective closure plate against the other stop surfaces, but it would only bring about almost play-free centering of the closure plates. 
     In addition, the clamping and centring of the closure plates could be implemented by means of a mechanism (not shown) which executes this by pivoting the slide unit towards the housing, and not only after the latter have both been braced together.