Crystallizer for continuous casting and method for its production

Abstract

Crystallizer for continuous casting comprising a tubular body having at least one wall which defines a through longitudinal casting cavity and a plurality of longitudinal grooves made at least on one part of the wall and open toward the outside thereof. A covering binding is associated to the external surface of the wall to close the longitudinal groves and thus obtain corresponding cooling channels configured to make a cooling liquid flow inside them.

1 . Crystallizer for continuous casting comprising a tubular body ( 11 ,  211 ) having at least one wall ( 12 ,  212 ) which defines a through longitudinal casting cavity ( 13 ,  213 ) and a plurality of longitudinal grooves ( 14 ) made at least on one part of said at least one wall ( 12 ,  212 ) and open toward the outside thereof, characterized in that a covering binding ( 15 ), comprising one or more layers of fiber material, is irremovably wound around said external surface of said at least one wall ( 12 ,  212 ). 
     
     
         2 . Crystallizer as in  claim 1 , characterized in that said covering binding ( 15 ) comprises at least a band ( 16 ) made using at least one fiber impregnated, or pre-impregnated, with polymer material. 
     
     
         3 . Crystallizer as in  claim 2 , characterized in that said polymer material, when polymerized around said wall ( 12 ,  212 ), determines the solid and irremovable attachment of said covering binding ( 15 ) with respect to said wall ( 12 ,  212 ). 
     
     
         4 . Crystallizer as in any claim hereinbefore, characterized in that said fiber material is wound in a direction mainly transverse to the longitudinal development of the wall ( 12 ,  212 ). 
     
     
         5 . Crystallizer as in any claim hereinbefore, characterized in that said fiber is chosen from a group comprising carbon fibers, glass fibers, aramid fibers or combinations thereof, and said polymer is chosen from a group comprising polyamide, epoxy or polyester resins. 
     
     
         6 . Crystallizer as in any claim hereinbefore, characterized in that said covering binding ( 15 ) is wound around and in direct contact with said external surface of said at least one wall ( 12 ,  212 ) and closes said longitudinal grooves ( 14 ) thus obtaining corresponding cooling channels ( 17 ) configured to make a cooling liquid flow inside them. 
     
     
         7 . Crystallizer as in any claim from  1  to  5 , wherein said longitudinal grooves ( 14 ) are closed by a metal layer ( 18 ) made using electrolytic deposition techniques that thus defines a corresponding plurality of cooling channels ( 17 ) configured to make a cooling liquid flow inside them, characterized in that said covering binding ( 15 ) is wound around and in direct contact with said metal layer ( 18 ) to make rigid the whole consisting of said at least one wall ( 12 ) and said metal layer ( 18 ). 
     
     
         8 . Crystallizer as in any claim from  1  to  5 , characterized in that said longitudinal grooves ( 14 ) are closed by a lamina ( 23 ) made of fiber-reinforced polymer material to define a corresponding plurality of cooling channels ( 17 ) configured to make a cooling liquid flow inside them, said covering binding ( 15 ) being wound around and in direct contact with said lamina ( 23 ) made of fiber-reinforced polymer material in order to make rigid the whole consisting of said at least one wall ( 12 ) and said lamina ( 23 ) made of fiber-reinforced polymer material ( 18 ). 
     
     
         9 . Crystallizer as in any claim from  1  to  5 , wherein said longitudinal grooves ( 14 ) are closed by at least a plate ( 219 ) associated to the external surface of said at least one wall ( 212 ) to define a corresponding plurality of cooling channels ( 17 ) configured to make a cooling liquid flow inside them, characterized in that said covering binding ( 15 ) is wound around and in direct contact with said at least one plate ( 219 ) to reinforce and increase the safety of the connection of the at least one plate ( 219 ) with said at least one wall ( 212 ). 
     
     
         10 . Crystallizer as in any claim hereinbefore, characterized in that said covering binding ( 15 ) has a thickness substantially constant along the longitudinal extension of said tubular body ( 11 ,  211 ). 
     
     
         11 . Crystallizer as in any claim from  1  to  9 , characterized in that said covering binding ( 15 ) has a variable thickness along the longitudinal extension of said tubular body ( 11 ,  211 ) to define zones of variable resistance and rigidity. 
     
     
         12 . Method to obtain a crystallizer ( 10 ,  110 ,  210 ) for continuous casting, comprising a step of making a tubular body ( 11 ,  211 ) having at least one wall ( 12 ,  212 ) which defines a through longitudinal casting cavity ( 13 ,  213 ) and a plurality of longitudinal grooves ( 14 ) made at least on one part of an external surface of said at least one wall ( 12 ,  212 ) and open toward the outside thereof, characterized in that it also comprises a step in which a covering binding ( 15 ), comprising one or more layers of fiber material, is irremovably wound around said external surface of said at least one wall ( 12 ,  212 ). 
     
     
         13 . Method as in  claim 12 , characterized in that said covering binding ( 15 ) comprises a band ( 16 ) made using at least one fiber impregnated, or pre-impregnated, with polymer material resistant to high temperatures, said band ( 16 ) being first wound around said external surface of said at least one wall ( 12 ,  212 ) and then the polymerization of said polymer material being provided in order to solidly attach said covering binding ( 15 ) with respect to said wall ( 12 ,  212 ). 
     
     
         14 . Method as in  claim 13 , characterized in that after said winding of said covering binding ( 15 ), it comprises a curing step during which said crystallizer ( 10 ,  110 ,  210 ) is heated to a temperature comprised between 30° C. and 120° C. and kept at this temperature for a period comprised between 20 and 200 minutes. 
     
     
         15 . Method as in  claim 14 , characterized in that after said curing step a post-curing step is provided during which said crystallizer ( 10 ,  110 ,  210 ) is heated to a temperature comprised between 80° C. and 200° C. and kept at this temperature for a period comprised between 1 hour and 20 hours. 
     
     
         16 . Method as in any claim from  12  to  15 , characterized in that said covering binding ( 15 ) is applied using the filament winding technique. 
     
     
         17 . Method as in any claim from  12  to  16 , characterized in that, before the winding of said one or more layers of fiber material, it provides to fill said longitudinal grooves ( 14 ) with disposable material, to deposit a metal layer ( 18 ) on the external surface of said at least one wall ( 12 ,  212 ) by means of electrolytic deposition techniques, in order to close said longitudinal grooves ( 14 ), and to subsequently remove said disposable material from said longitudinal grooves ( 14 ) so as to define corresponding cooling channels ( 17 ). 
     
     
         18 . Method as in any claim from  12  to  16 , characterized in that, before the winding of said one or more layers of fiber material, it provides to close said longitudinal grooves ( 14 ) with at least one lamina ( 23 ) made of a fiber-reinforced polymer material to define a plurality of cooling channels ( 17 ), and in that during said winding, said fiber material is wound around and in direct contact with said lamina ( 23 ) made of fiber-reinforced polymer material. 
     
     
         19 . Method as in any claim from  12  to  16 , characterized in that, before the winding of said one or more layers of fiber material, it provides to close said longitudinal grooves ( 14 ) with at least a plate ( 219 ) associated to the external surface of said at least one wall ( 212 ) so as to define a corresponding plurality of cooling channels ( 17 ). 
     
     
         20 . Method as in any claim from  12  to  19 , characterized in that said fiber material is wound around said wall ( 12 ;  212 ) at a winding angle comprised between 0° and 10°, preferably between 0° and 5°, with respect to the perpendicular to the axis of longitudinal development of the crystallizer ( 10 ). 
     
     
         21 . Method as in any claim from  12  to  20 , characterized in that said covering binding ( 15 ) comprises a band made using at least a fiber impregnated or pre-impregnated with glue or polymer resin, said covering binding ( 15 ) having a volumetric ratio of fibers of 60%, and glue or polymer resin of 40%. 
     
     
         22 . Method as in any claim from  12  to  21 , characterized in that during the winding of said fiber material, fibers making up said covering binding ( 15 ) are wound at a controlled tension between 1N and 50N.