Patent Publication Number: US-6904953-B2

Title: Cooling arrangement for the rolling stand of a continuous casting system

Description:
BACKGROUND AND SUMMARY OF INVENTION 
   This application claims the priority of European Patent Application 02004596.9 filed Feb. 28, 2002, the disclosure of which is expressly incorporated by reference herein. 
   The invention relates to a cooling arrangement for the rolling stand of a continuous casting system for heavy supports with spraying nozzles which can be acted upon by a cooling liquid and by compressed air through lateral supply pipes laid in the longitudinal direction of the rolling stand. 
   Cooling arrangements of this general type are known.  FIG. 3  shows such an arrangement. Such pipe and nozzle arrangements for supplying the secondary cooling system of the continuous casting system, for a further development with two nozzles for each side, have at least three pipes. In this case, one pipe, for example, pipe L, supplies compressed air which is guided through a T-piece to both spraying nozzles D, and the two other pipes W supply the cooling liquid in the form of water to one of the spraying nozzles respectively. These three lines L and W extend parallel to the casting billet S which is to be shaped here into the shape of a double-T support within the rolling stand, in which various rollers R 1 , R 2  and R 3  shape the billet S. The spraying nozzles D are in each case arranged such that they spray into the gaps between adjacent rollers R 1  and in this case, if possible, contact the entire lateral surface of the billet S with their spraying jet. 
   Since the feed pipes W and L extend parallel to the billet S, they have to be laid outside the respective segment frame. The supply with compressed air and water takes place by way of relatively thin lines L 1  which have to be bent corresponding to the spraying direction. As illustrated in  FIG. 3 , for this purpose, at least three of the stub lines L 1 , of which two are bent, are required, as well as a distributor piece which is situated in-between and is provided here for the compressed air supply, but may also be provided for the water supply if compressed air is guided through the exterior pipes W. 
   The installation of such a pipe arrangement requires relatively high expenditures. A precise alignment of the spraying nozzles D with respect to the target surface of the billet S is difficult and, depending on the quality of the maintenance, there is also a considerable risk that areas of the billet S are acted upon which are to remain uncooled. In addition, the removal of an individual nozzle for maintenance purposes is not possible without the removal of the complete supply pipes W, L. 
   It is therefore an object of the present invention to further develop a cooling arrangement of the initially mentioned type such that its construction is simpler and operationally more reliable and that the mounting and installation expenditures can be kept as low as possible. 
   For achieving this object, it is provided in the case of a cooling arrangement of the initially mentioned type that only one cooling liquid and compressed-air pipe respectively is assigned to each rolling stand side, which are laid parallel to one another and are provided with connection points for the joining of connection plates which are fixedly connected with the spraying nozzles. 
   This further development requires only two pipes for supplying the secondary cooling system with air and water. Bent stub lines or distributor pieces, which are difficult to manufacture and require high expenditures, will therefore not be necessary. The flanging of a connection plate to the two supply pipes, which have corresponding connection points, is sufficient. These connection plates, in turn, will then already carry the correspondingly aligned or arranged spraying nozzles. As a result, the mounting or demounting becomes significantly simpler. 
   As a further development of certain preferred embodiments of the invention, the connection points at the supply pipes can be constructed as a flange to which the connection plates can be joined in a simple manner. It is also advantageous according to certain preferred embodiments of the invention to place the two supply pipes at a narrow distance from one another so that they can be provided in a simple manner with a joint connection flange for fastening the connection plates. 
   In principle, this results in the possibility to provide the connection flanges only on one side on the supply pipes and to provide a connecting link on the other side of the supply pipes, so that studs for mounting the connection plates can be guided through the space between the supply pipes and can be anchored in the connecting link. 
   However, it is also contemplated to provide the connection flanges on both sides on the supply pipes and to provide them with one connection thread for studs respectively for the flanging-on of the connection plates for certain preferred embodiments of the invention. 
   As a further development of certain preferred embodiments of the invention, the connection plate can be fixedly connected with two spacer pipes, of which one is connected with the compressed air and the other is connected with the cooling-liquid pipe, the spacer pipes ending in a flange which can be fixedly connected with the nozzle housing which is provided with two spraying nozzles situated at a certain angle with respect to the one another and to the axes of the spacer pipes. In this case, these spraying nozzles are connected in this housing with a mixing chamber and with ducts for guiding the compressed air and the cooling liquid. The connection plate also has passage openings to the spacer pipes which adjoin the connection flanges of the supply pipes in a sealed-off manner. 
   In the case of a variant of the invention, it may, however, also be provided that the connection plate itself is provided with a mixing chamber in the interior which, by way of connection ducts, is connected with the compressed-air and the cooling-liquid connection and has an outlet connection piece which is connected with a connection pipe piece to a spraying nozzle. In the case of this embodiment, the mixing of cooling liquid and compressed air can therefore take place within the connection plate and the spraying mixture will then be supplied to the assigned spraying nozzle or to several assigned spraying nozzles. 
   In this last mentioned embodiment, the connection pipe piece to the spraying nozzles can have a bent construction with respect to the laying plane of the supply pipes. It can also be detachably joined to the outlet connection piece and be provided with a protection against torsion which ensures that the connection pipe pieces to the spraying nozzles can be attached to the outlet connection piece only in a defined position. This further development therefore ensures the alignment of the spraying jet, so that an operator will not have to adjust this spraying angle by bending pipes in a high-expenditure manner. As a result, it is also possible to implement both spraying positions by means of an identical connection piece with a spraying nozzle. 
   The invention is illustrated in the drawing by means of two embodiments and will be explained in the following. 
   Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic view of a spraying nozzle arrangement of a cooling arrangement according to a preferred embodiment of the invention, having two spraying nozzles arranged in a housing block and a spacer pipe arrangement, viewed in a longitudinal direction of a billet being formed; 
       FIG. 2  is a view similar to  FIG. 1  showing another preferred embodiment of the invention, with a cooling arrangement with two spraying nozzles to be flanged on separately; and 
       FIG. 3  is a schematic cross-sectional view of a rolling stand of a continuous casting system with a cooling arrangement according to the prior art. 
   

   DETAILED DESCRIPTION OF THE DRAWINGS 
     FIG. 1  illustrates that two supply pipes  1  and  2  each having a square or rectangular cross-section are laid at a narrow mutual distance in the longitudinal direction of the billet S and parallel to its center plane  17 , which billet is guided and shaped, as explained by means of  FIG. 3 , in a rolling stand of a continuous casting system. The two supply pipes  1  and  2 , of which one is used for supplying compressed air and the other is used for supplying cooling liquid or water, are connected with one another by links  3  arranged at certain distances on the one side and by connection flanges  4  each situated opposite the links  3 , and are provided in each case with openings  1   a  and  2   a  respectively on the side of the connection flanges  4 , by way of which openings  1   a  and  2   a  respectively compressed air or water can enter into corresponding passage openings respectively of the flanges. 
   One connection plate in the form of a flange  5  of a spacer pipe unit  6  respectively is joined to each connection flange  4 , which spacer pipe unit  6  includes two spacer pipes  7  and  8  and another flange  9  to which, again by means of screws  10 , a nozzle housing  11  is flanged. In a manner not illustrated in detail, this nozzle housing  11  is provided with a mixing chamber in the interior, into which compressed air and cooling liquid penetrates from the spacer pipes  7  and  8  and is mixed. The coolant/compressed-air mixture is then fed to the two spraying nozzles  12  and  13  which are aligned at an angle α with respect to one another which had previously been adapted to the shape of the billet S together with the spraying pattern of the spraying jet  14 . 
   The cooling system and the rolling stand respectively are also adapted to the length of the spacer pipes  7  and  8 . 
   It is easily recognizable that, in the case of such an embodiment, the spacer pipe unit  6  can be joined in a simple manner to the flange  4  and can be fastened by means of a stud  15  which extends through the flanges  4  and  5 , through the gap between the supply pipes  1  and  2  and through the link  3 . In this case, it is possible to ensure a precise alignment of the spacer pipe unit  6  and therefore also of the spraying nozzles  12  and  13  by means of alignment pins  16  which permit an exact mutual alignment of the flanges  4  and  5 . 
   It is also plausible that, in this embodiment, only two supply pipes are required and that the maintenance of the nozzles  12 ,  13  is significantly easier because, for this purpose, after the release of the stud  15 , the entire spacer unit  6  together with the nozzle housing  1  can be removed in a simple manner without the requirement of demounting the supply pipes  1 ,  2 . After the reattaching of the spacer pipe unit, the spraying nozzles  12 ,  13  will be precisely aligned again without the requirement of cumbersome adjusting operations. The spraying nozzles  12 ,  13  or their mouthpieces are restrictedly aligned at the nozzle housing  11 , which also applies to the arrangement of the nozzle housing  11  with respect to the spacer pipe unit  6  and to the alignment of the spacer pipe unit  6  with respect to the supply pipes  1  and  2 . 
     FIG. 2  shows a variant of a cooling arrangement according to the invention. Here, the two supply pipes  1  and  2  are again aligned parallel to one another, side-by-side and parallel to the center plane  17  of the billet S. However, here they are also not arranged below one another but side-by-side in a horizontal laying plane  25  and are equipped on their top side as well as on their underside with flanges  4  which, again by way of their passage openings, establish the connection to the compressed air and the cooling liquid supply. The connection plates  18  are in each case joined to the two flanges  4 , by way of which connection plates  18  one spraying nozzle  19  respectively is supplied which is provided with a bent connection pipe piece  20 . In a manner not shown in detail here, one mixing chamber respectively is provided inside the connection plate  18 , in which mixing chamber, the compressed air and the cooling liquid are mixed and are then guided by way of a connection piece  21  and the connection pipe piece  20  to the spraying nozzles  19 . Also in this case, the spraying jets  14  are adapted to the shape of the billet S, which also applies to the bending angle of the connection pipe piece  20 . This connection pipe piece  20  is connected in a torsion-proof manner with the connection piece  21  of the connection plate  18  and is secured by way of a union nut, so that the connection pipe piece  20  can be joined to the connection piece  21  only in a defined position. The spraying nozzle  19  can therefore be aligned only in the position indicated on top or in the position indicated below, the two positions occurring by a 180° rotation of the connection plates  18 . In this embodiment, the connection plates  18  may also be provided with a regulating device  22  for controlling the compressed-air/cooling liquid ratio. 
   Also this embodiment permits an easy and precise mounting or demounting in that the stud  23 , which in each case holds the connection plate  18  on the flange  4 , is released and the corresponding spraying nozzle unit is removed, is serviced and is then attached again in a precise manner. The torsion-proof connection between the connection pipe piece  20  and the connection piece  21  and its securing by means of a union nut  24  is known per se and will therefore not be explained in detail. 
   The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.