Patent Publication Number: US-11389863-B2

Title: Collector nozzle for continuous casting

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a National Phase of PCT International Application No. PCT/KR2018/008727 with an International Filing Date of Jul. 31, 2018, which claims under 35 U.S.C. § 119(a) the benefit of Korean Application No. 10-2018-0021137, filed on Feb. 22, 2018, the entire contents of which are incorporated by reference herein. 
     BACKGROUND 
     (a) Technical Field 
     The present disclosure relates to a collector nozzle for continuous casting, more particularly, to the collector nozzle which can prevent base metal from adhering to a shroud facing the collector nozzle. 
     (b) Description of the Related Art 
     In general, a continuous caster refers to equipment which receives molten steel, which is made in a steel making furnace and transferred to a ladle, in a tundish and supplies the molten steel to a mold for the continuous caster to manufacture a casting. In order to transfer the molten steel from the ladle to the tundish, a collector nozzle coupled to the ladle and a shroud nozzle installed at the top of the tundish are used. 
     One example of related art to the present disclosure is disclosed in Korean Patent No. 10-1790002 registered on Oct. 19, 2017 and entitled “Nozzle, Apparatus of Continuous Casting and Method thereof”. 
     SUMMARY 
     Embodiments of the present disclosure are directed to a collector nozzle for continuous casting, which can prevent base metal from adhering to a shroud facing the collector nozzle. 
     In an embodiment, a collector nozzle for continuous casting may include: a nozzle body extended toward a shroud nozzle, and having an internal movement path through which molten steel is moved; a first case covering a side surface of the nozzle body; and a second case including a second metal component, connected to the first case, and covering an exit surface of the nozzle body facing the shroud nozzle. 
     The first case may include a first metal component, and the first and second cases are connected through welding or formed as one body. 
     The second case may cover the entire exit surface. 
     The second case may cover an edge of the exit surface. 
     The collector nozzle may further include a protrusion part having a plurality of protrusion members extended downward from the second case. 
     The protrusion members of the protrusion part may be arranged in a zigzag shape in a circumferential direction of the second case. 
     The protrusion part may be obliquely installed in a diagonal direction. 
     The protrusion part may include a third metal component. 
     In the collector nozzle for continuous casting in accordance with the embodiment of the present disclosure, the second case including a second metal component is installed at the bottom of the nozzle body, and base metal formed between the nozzle body and the shroud nozzle adheres to the second case and is automatically removed, which makes it possible to reduce a maintenance cost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram schematically illustrating that a collector nozzle for continuous casting in accordance with an embodiment of the present disclosure is installed. 
         FIG. 2  is a cross-sectional view of the collector nozzle for continuous casting in accordance with the embodiment of the present disclosure. 
         FIG. 3  is a cross-sectional view illustrating that base metal is formed between a shroud nozzle and the collector nozzle for continuous casting in accordance with the embodiment of the present disclosure. 
         FIG. 4  is a cross-sectional view illustrating that base metal adheres to a second case in accordance with the embodiment of the present disclosure. 
         FIG. 5  is a cross-sectional view illustrating that a protrusion part is additionally installed on the second case in accordance with the embodiment of the present disclosure. 
         FIG. 6  is a bottom view illustrating that the protrusion part in accordance with the embodiment of the present disclosure is installed in a zigzag shape along the second case. 
         FIG. 7  is a cross-sectional view illustrating that the protrusion part in accordance with the embodiment of the present disclosure is obliquely installed. 
         FIG. 8  is a cross-sectional view illustrating that a second case in accordance with another embodiment of the present disclosure is installed. 
         FIG. 9  is a cross-sectional view illustrating that a protrusion part is installed on the second case in accordance with the embodiment of the present disclosure. 
         FIG. 10  is a bottom view illustrating that the protrusion part in accordance with the embodiment of the present disclosure is installed in a zigzag shape along the second case. 
         FIG. 11  is a cross-sectional view illustrating that the protrusion part in accordance with the embodiment of the present disclosure is obliquely installed. 
     
    
    
     DETAILED DESCRIPTION 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the specification, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. In addition, the terms “unit”, “-er”, “-or”, and “module” described in the specification mean units for processing at least one function and operation, and can be implemented by hardware components or software components and combinations thereof. Further, the control logic of the present disclosure may be embodied as non-transitory computer readable media on a computer readable medium containing executable program instructions executed by a processor, controller or the like. Examples of computer readable media include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards and optical data storage devices. The computer readable medium can also be distributed in network coupled computer systems so that the computer readable media is stored and executed in a distributed fashion, e.g., by a telematics server or a Controller Area Network (CAN). 
     Hereafter, a collector nozzle for continuous casting in accordance with an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that the drawings are not to precise scale and may be exaggerated in thickness of lines or sizes of components for descriptive convenience and clarity only. 
     Furthermore, the terms as used herein are defined by taking functions of the present disclosure into account and can be changed according to the custom or intention of users or operators. Therefore, definition of the terms should be made according to the overall disclosures set forth herein. 
       FIG. 1  is a diagram schematically illustrating that a collector nozzle for continuous casting in accordance with an embodiment of the present disclosure is installed,  FIG. 2  is a cross-sectional view of the collector nozzle for continuous casting in accordance with the embodiment of the present disclosure,  FIG. 3  is a cross-sectional view illustrating that base metal is formed between a shroud nozzle and the collector nozzle for continuous casting in accordance with the embodiment of the present disclosure,  FIG. 4  is a cross-sectional view illustrating that base metal adheres to a second case in accordance with the embodiment of the present disclosure,  FIG. 5  is a cross-sectional view illustrating that a protrusion part is additionally installed on the second case in accordance with the embodiment of the present disclosure,  FIG. 6  is a bottom view illustrating that the protrusion part in accordance with the embodiment of the present disclosure is installed in a zigzag shape along the second case, and  FIG. 7  is a cross-sectional view illustrating that the protrusion part in accordance with the embodiment of the present disclosure is obliquely installed. 
     As illustrated in  FIGS. 1 to 4 , the collector nozzle  1  for continuous casting in accordance with the embodiment of the present disclosure includes a nozzle body  40 , a first case  50  and a second case  60 . The nozzle body  40  is extended toward a shroud nozzle  30  and has an internal movement path  42  for molten steel  15 . The first case  50  covers a side surface of the nozzle body  40 . The second case  60  includes a second metal component, is connected to the first case  50 , and covers an exit surface  46  of the nozzle body  40  facing the shroud nozzle  30 . 
     Continuous casting refers to a casting method for continuously casting slabs or steel ingots while molten metal is solidified in a mold with no bottom. The continuous casting is used to manufacture an elongated product having a simple cross-section such as a square, rectangle or circle and a slab, bloom or billet which is mainly used as a material for rolling. The continuous casting is performed through a ladle  10  and a tundish  20 . 
     The ladle  10  has an internal space for containing the molten steel  15  which has steel component content formed through a refining process. The tundish  20  receives the molten metal from the ladle  10  and supplies the molten metal to the mold. The ladle  10  is provided as a pair of ladles which alternately receive the molten steel  15  and supply the molten steel  15  to the tundish  20 . 
     In order to guide the molten steel  15  from the ladle  10  to the tundish  20 , the shroud nozzle  30  and the collector nozzle  1  for continuous casting are used. The collector nozzle  1  for continuous casting is connected to the ladle  10 , and the shroud nozzle  30  is installed at the bottom of the collector nozzle  1  for continuous casting. 
     Since the structure for moving the molten steel  15  in the ladle  10  to the tundish  20  through the collector nozzle  1  for continuous casting and the shroud nozzle  30  is publicly known, the detailed descriptions thereof will be omitted herein. Furthermore, since the structure in which the shroud nozzle  30  is erected at the top of the tundish  20  is also publicly known, the detailed descriptions thereof will be omitted herein. 
     The shroud nozzle  30  in accordance with the embodiment includes a shroud body  32  and a guide member  34 . The shroud body  32  is extended in the top-to-bottom direction and has an internal path through which the molten steel  15  is moved, and the guide member  34  is spread obliquely toward the outside from the top of the shroud body  32 . The shroud nozzle  30  is made of a refractory material, and prevents oxidation when the molten steel  15  is guided. 
     The nozzle body  40  is extended toward the shroud nozzle  30 , and has the internal movement path  42  for the molten steel  15 . The upper part of the nozzle body  40  is connected to the ladle  10 , and the lower part of the nozzle body  40  is located inside the guide member  34  of the shroud nozzle  30 . 
     The nozzle body  40  is extended in the top-to-bottom direction, and has an outer inclined surface  44  formed at a side surface of the lower part thereof. The nozzle body  40  having the outer inclined surface  44  has an outer diameter that gradually decreases toward the bottom thereof. The outer inclined surface  44  formed at the lower part of the nozzle body  40  has the same or similar angle as or to an inclined surface formed inside the guide member  34  of the shroud nozzle  30 . Therefore, since the nozzle body  40  is guided downward along the guide member  34 , the nozzle body  40  and the shroud nozzle  30  may be rapidly and easily connected to each other. 
     The nozzle body  40  has the ring-shaped exit surface  46  formed at the bottom thereof in a horizontal direction, and the second case  60  may be deformed in various manners to cover the entire exit surface  46  or only the edge  48  of the exit surface  46 . 
     The first case  50  is installed in a shape to cover the side surface of the nozzle body  40 . The second case  60  includes a second metal component, is connected to the first case  50 , and covers the entire exit surface  46  of the nozzle body  40  facing the shroud nozzle  30 . 
     The first case  50  is installed in a shape to cover the lateral outer surface of the nozzle body  40 , and the second case  60  is installed in a shape to cover the exit surface  46  formed at the bottom of the nozzle body  40 . The first case  50  and the second case  60  are connected through welding or formed as one body. 
     The nozzle body  40  is made of a refractory material such as ceramic, and the first and second cases  50  and  60  preferably each include a metal component (e.g., first and second metal components, respectively). Therefore, base metal  17  formed between the collector nozzle  1  for continuous casting and the shroud nozzle  30  adheres to the second case  60  including the second metal component. 
     Since the second case  60  covers the entire exit surface  46 , the base metal  17  formed between the collector nozzle  1  for continuous casting and the shroud nozzle  30  adheres to the second case  60 . The temperature of the molten steel moved downward through the movement path  42  of the nozzle body  40  is about 1,550° C., and the second case  60  is heated at a temperature of 1,000° C. to 1,400° C. with the collector nozzle  1  lowered to face the shroud nozzle  30 . Therefore, the base metal  17  adheres to the second case  60  while the second case  60  including steel is partially molten. 
     Since the first case  50  is installed in such a manner that the outside of the first case  50  abuts on the inner surface of the guide member  34 , fluid including gas is blocked from moving between the guide member  34  and the first case  50 . Therefore, since a separate sealing member for blocking fluid from moving between the guide member  34  and the first case  50  is omitted, an installation cost and maintenance cost can be reduced. 
     In order to improve the sealing performance between the first case  50  and the guide member  34 , the inclination angles of the outer surface of the first case  50  and the inner surface of the guide member  34  are equal or similar to each other within an error range. Thus, the surface contact between the first case  50  and the guide member  34  may be induced to improve the sealing performance. 
     The first and second cases  50  and  60  may be made of a material each including a metal component (e.g., the first and second metal components, respectively). Alternatively, only the second case  60  may be made of a material including the second metal component, and the first case  50  may be made of a material which includes a smaller amount of the first metal component than the second case  60  or no first metal component. 
     When the second case  60 , which is installed in the horizontal direction while covering the lower end of the nozzle body  40 , is located inside the shroud nozzle  30 , a space in which the base metal  17  is to be formed is provided between the second case  60  and the guide member  34 . Therefore, the base metal  17  formed between the second case  60  and the guide member  34  of the shroud nozzle  30  may easily adhere to the second case  60  located on the top side. The second case  60  in accordance with the embodiment is used for the adherence of the base metal  17 , and may be deformed in various shapes and made of various materials, as long as the base metal  17  formed between the shroud nozzle  30  and the second case  60  can easily adhere. 
     When the base metal  17  adheres to the shroud nozzle  30 , the shroud nozzle  30  needs to be lifted from the molten steel  15  and subjected to oxygen cleaning, in order to remove the base metal  17  on the shroud nozzle  30 . Thus, the manufacturing process is stopped, which results in reducing the productivity. Furthermore, the base metal  17  removed from the shroud nozzle  30  falls into the tundish  20  and thus degrades the quality of the molten steel  15 . Moreover, since a worker needs to work in a high-temperature environment, the stability of the work may be reduced. 
     Furthermore, when the shroud nozzle  30 , which has been cleaned with oxygen to remove the base metal  17 , is installed in the tundish  20  again with slag floating on the surface of the molten steel  15  in the tundish  20 , air may be introduced into the molten steel  15 , and the slag floating on the molten steel  15  may be mixed with the molten steel  15 , thereby degrading the quality of the molten steel  15 . 
     According to the collector nozzle  1  for continuous casting in accordance with the embodiment of the present disclosure, the base metal  17  does not adhere to the shroud nozzle  30 , but adheres to the second case  60  of the collector nozzle  1  for continuous casting and moves toward the top of the shroud nozzle  30 . Therefore, an oxygen cleaning work for removing the base metal  17  from the shroud nozzle  30  does not need to be performed, and the shroud nozzle  30  may be continuously used while erected at the top of the tundish  20 . Therefore, it is possible to prevent the degradation in work stability and the reduction in quality and productivity of the molten steel  15 , which may occur when the shroud nozzle  30  is cleaned. 
     In general, the collector nozzle  1  for continuous casting cannot be reused after one use, and the shroud nozzle  30  can be continuously reused. Therefore, the base metal  17  may be induced to adhere to the second case  60  of the collector nozzle  1  for continuous casting, which is discarded after one use, in order to minimize the base metal  17  adhering to the shroud nozzle  30 . Thus, the state in which the shroud nozzle  30  is installed in the tundish  20  can be continuously maintained, and the attachment/detachment period of the shroud nozzle  30  can be increased. 
     When the collector nozzle  1  for continuous casting is lifted, the second case  60  having the base metal  17  adhering thereto is lifted together. Thus, the operation of removing the base metal  17  from the shroud nozzle  30  can be stably performed. 
     As illustrated in  FIG. 5 , the collector nozzle  1  for continuous casting in accordance with the embodiment further includes a protrusion part  70  having a plurality of protrusion members  72  extended downward from the second case  60 . The plurality of protrusion members  72  protrude downward from the second case  60 . The protrusion members  72  may be formed in various shapes such as a rod shape extended in a vertical or diagonal direction, as long as the protrusion members  72  can protrude downward from the second case  60  and increase a contact area with the base metal  17 . Therefore, the base metal  17  may more easily adhere to the second case  60  and the protrusion part  70  having an increased contact area with the base metal  17 , and be removed from the shroud nozzle  30 . Since the protrusion part includes a third metal component (where the “third” metal component may be the same or different than the first and second metal components of the first and second cases, respectively), the base metal  17  adheres to the second case  60  and the protrusion part, with the protrusion part  70  and the second case  60  partially molten. Therefore, since an area for fixing the base metal  17  moved upward with the collector nozzle  1  for continuous casting is increased, it is possible to significantly reduce the possibility that the base metal  17  will fall down to cause an accident. 
     The protrusion part  70  in accordance with the embodiment of the present disclosure may be installed in such a shape that a plurality of protrusion members  72  are extended downward from the second case  60 . As illustrated in  FIG. 6 , a plurality of protrusion members  73  of the protrusion part  70  may be arranged in a zigzag shape in the circumferential direction of the second case  60 . Since the protrusion members  73  are arranged in a zigzag shape and connected to the second case  60 , the distance between the adjacent protrusion members  73  can be easily secured. Therefore, although a smaller number of protrusion members  73  are installed, the base metal  17  may easily adhere and move. 
     Alternatively, as illustrated in  FIG. 7 , protrusion members  74  of the protrusion part  70  may be obliquely installed in a diagonal direction. Therefore, it is possible to prevent the base metal  17  from falling down during a work of lifting the base metal  17  adhering to the protrusion members  74  and the second case  60 , thereby significantly reducing the possibility that an accident will occur. 
     Hereafter, the operation state of the collector nozzle  1  for continuous casting in accordance with the embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. 
     As illustrated in  FIG. 1 , the collector nozzle  1  for continuous casting is located at the top of the shroud nozzle  30 , with the first and second cases  50  and  60  installed outside the nozzle body  40 . The molten steel  15  in the ladle  10  is moved to the tundish  20  through the collector nozzle  1  for continuous casting and the shroud nozzle  30 . 
     At this time, as illustrated in  FIG. 3 , the base metal  17  is formed between the second case  60  and the guide member  34 , as the molten steel  15  is solidified. The base metal  17  adheres to the second case  60  whose surface is molten. Therefore, when the collector nozzle  1  for continuous casting and the shroud nozzle  30  are separated after the work for moving the molten steel  15  is completed, the base metal  17  adheres to the second case  60  and is removed from the shroud nozzle  30 . 
     Alternatively, when the protrusion part  70  is additionally installed on the bottom of the second case  60  illustrated in  FIGS. 5 to 7 , the base metal  17  adhering to both of the protrusion part  70  and the second case  60  may be moved upward with the collector nozzle  1  for continuous casting, which makes it possible to prevent the base metal from adhering to the shroud nozzle  30 . 
     Hereafter, a collector nozzle  1  for continuous casting in accordance with another embodiment of the present disclosure will be described with reference to the drawings. 
     For convenience of description, components which are configured and operated in the same manner as those of the controller nozzle in accordance with the above embodiment will be represented by like reference numerals, and the detailed descriptions thereof will be omitted. 
       FIG. 8  is a cross-sectional view illustrating that a second case in accordance with another embodiment of the present disclosure is installed,  FIG. 9  is a cross-sectional view illustrating that a protrusion part is installed on the second case in accordance with the embodiment of the present disclosure,  FIG. 10  is a bottom view illustrating that the protrusion part in accordance with the embodiment of the present disclosure is installed in a zigzag shape along the second case, and  FIG. 11  is a cross-sectional view illustrating that the protrusion part in accordance with the embodiment of the present disclosure is obliquely installed. 
     As illustrated in  FIG. 8 , a second case  65  installed in a collector nozzle  1  for continuous casting in accordance with another embodiment of the present disclosure covers an edge  48  of an exit surface  46 . Although the second case  65  does not cover the entire area of the exit surface  46 , a part of the second case  65  installed in the horizontal direction abuts on base metal  17  formed between the collector nozzle  1  for continuous casting and the shroud nozzle  30 . Thus, the base metal  17  may easily adhere to the second case  65 . 
     As illustrated in  FIG. 9 , the second case  65  in accordance with the embodiment of the present disclosure may further include a protrusion part  80  having a plurality of protrusion members  82 . Even in such a case, the base metal  17  may easily adhere to the collector nozzle  1  for continuous casting. 
     The protrusion part  80  in accordance with the embodiment of the present disclosure may be installed in such a shape that the plurality of protrusion members  82  are extended downward from the second case  65 . As illustrated in  FIG. 10 , the plurality of protrusion members  83  of the protrusion part  80  may be arranged in a zigzag shape in the circumferential direction of the second case  65 . Since the protrusion members  83  are arranged in a zigzag shape and connected to the second case  65 , the distance between the adjacent protrusion members  83  can be easily secured. Therefore, although a smaller number of protrusion members  83  are installed, the base metal  17  may easily adhere and move. 
     Alternatively, as illustrated in  FIG. 11 , protrusion members  84  of the protrusion part  80  may be obliquely installed in a diagonal direction. Therefore, it is possible to prevent the base metal  17  from falling down during a work of lifting the base metal  17  adhering to the protrusion members  84  and the second case  65 , thereby significantly reducing the possibility that an accident will occur. 
     In accordance with the present disclosure, the second case  60  or  65  including the second metal component is installed at the bottom of the nozzle body  40 , and the base metal  17  formed between the nozzle body  40  and the shroud nozzle  30  adheres to the second case  60  or  65  and is automatically removed, which makes it possible to reduce a maintenance cost. Furthermore, since the protrusion part  70  or  80  is additionally installed on the second case  60  or  65  to induce the adherence of the base metal  17 , it is possible to prevent the base metal  17  from falling down during a work of removing the base metal  17  from the shroud nozzle  30 , thereby significantly reducing the possibility that an accident will occur. 
     Although some embodiments have been provided to illustrate the present disclosure in conjunction with the drawings, it will be apparent to those skilled in the art that the embodiments are given by way of illustration only, and that various modifications and equivalent embodiments can be made without departing from the spirit and scope of the present disclosure. The scope of the present disclosure should be limited only by the accompanying claims.