Abstract:
Disclosed herein are an apparatus and method for manufacturing a compressed lump of metal scrap that is capable of compressing various kinds of collected metal scrap into a standardized form so that the metal scrap can be directly introduced into a blast furnace. A through hole is formed in a compressed lump of metal scrap during manufacture of the compressed lump of metal scrap so that the compressed lump of metal scrap can be efficiently melted and the interior of the compressed lump of metal scrap can be observed.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an apparatus and method for manufacturing a compressed lump of metal scrap that is capable of compressing various kinds of collected metal scrap into a standardized form so that the metal scrap can be directly introduced into a blast furnace. 
         [0003]    2. Description of the Related Art 
         [0004]    As is generally known, various kinds of metal scrap, including materials dug from various production fields or used molds disposed from various production fields, reinforcing rods obtained from demolished buildings, and metal waste, such as scrapped vehicles, disused gas containers or cans obtained from various consumption fields, are collected, sorted, and melted to manufacture various kinds of steel materials, thereby reducing resources and energy used to manufacture steel materials and eventually protecting environment. 
         [0005]    To this end, metal scrap is basically sorted according to kinds of the metal scrap and is compressed into a compressed lump of metal scrap which is formed and standardized so that the compressed lump of metal scrap can be directly introduced into a blast furnace of a steel mill, to which the compressed lump of metal scrap is supplied. 
         [0006]    Such a compressed lump of metal scrap is generally configured so that the sum of the width, length, and height of the compressed lump of metal scrap is between 600 mm and 2100 mm. Also, metal scrap is compressed so that a compressed lump of metal scrap has the maximum length of less than 800 mm and a density of 0.15 or more. 
         [0007]    In a conventional apparatus for manufacturing such a compressed lump of metal scrap, metal scrap, including ferrous metal scrap and nonferrous metal scrap, such as aluminum and copper, collected via various routes is sorted and compressed by a compression apparatus to form a compressed lump of metal scrap in the shape of a hexahedral body having a predetermined standard. A representative example of the apparatus for manufacturing the compressed lump of metal scrap is disclosed in Japanese Utility Model Publication No. S38-11798 entitled “Scrap press apparatus” (hereinafter, referred to as a ‘cited invention’). 
         [0008]    The cited invention provides a scrap press apparatus configured to have a structure in which a slide type upper cover  1  is installed above a scrap molding chamber  2  having a press plate  5  and transverse press plates  20  provided at left and right sides thereof, a stationary cover unit  3  is installed above a material molding side of the scrap molding chamber  2 , a lower cover  7 , which can be freely opened and closed, to discharge a shaped product is installed under the material molding side of the scrap molding chamber  2 , a shearing cutter  4  is installed at a contact portion between the stationary cover unit  3  and the slide type cover, and a shearing cutter  6  is installed above the press plate  5 . In the cited invention, metal scrap is charged into the scrap molding chamber  2 , the upper cover  1  is closed, and a primary cylinder  14  is driven to advance a piston  13 . As a result, the press plate  5  primarily compresses metal scrap in the scrap molding chamber  2  into a form as indicated by a dotted line of  FIG. 2 . Subsequently, the opposite transverse press plates  20  are advanced to the middle of the scrap molding chamber  2  by pistons  22  of cylinders  21  to secondarily compress the primarily compressed metal scrap. After the metal scrap is secondarily compressed, a lower cover actuating cylinder  8  connected to the lower side of the lower cover  7  is driven to pull the middle of a link  10 . As a result, the lower cover  7  is opened to the lower side, and therefore, a compressed lump  23  of metal scrap falls and is carried outside by a conveyor  18 . 
         [0009]    A required number of compressed lumps of metal scrap of a predetermined standard manufactured according to the cited invention with the above-stated construction are directly introduced into a blast furnace to manufacture various kinds of steel products. Consequently, a very efficient operation is possible. 
         [0010]    On the other hand, such a compressed lump of metal scrap is obtained by compressing a large amount of metal scrap with high density so that the volume of the compressed lump of metal scrap is small. For this reason, the compressed lump of metal scrap has large thermal capacity, and therefore, it is necessary to heat the compressed lump of metal scrap for a long time using a large amount of energy so as to melt the compressed lump of metal scrap. Consequently, a large amount of energy is consumed in a melting process with the result that costs necessary to manufacture steel products are greatly increased. Also, a discharge amount of carbon is increased as a large amount of energy is consumed with the result that environment is polluted. 
         [0011]    As a rule, metal scrap must be sorted according to ingredients of the metal scrap so that pure nonferrous metal scrap or pure ferrous metal scrap can be separately compressed to manufacture such a compressed lump of metal scrap. However, some thoughtless processors mix concrete, which is heavy, with metal scrap to manufacture a poor compressed lump of metal scrap. If such a poor compressed lump of metal scrap is introduced into a blast furnace, the blast furnace is contaminated by impurities. Enormous expense is needed to remove contaminants from the blast furnace, and, in addition, a production project is frustrated. As a result, steelmakers have difficulty in using a compressed lump of metal scrap. 
       SUMMARY OF THE INVENTION 
       [0012]    Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide an apparatus and method for forming a through hole in a compressed lump of metal scrap during manufacture of the compressed lump of metal scrap so that the compressed lump of metal scrap can be efficiently melted and the interior of the compressed lump of metal scrap can be observed instead of drilling a finished compressed lump of metal scrap to form a through hole in the compressed lump of metal scrap as in the cited invention, thereby efficiently producing the compressed lump of metal scrap. 
         [0013]    In accordance with the present invention, the above and other objects can be accomplished by the provision of an apparatus for manufacturing a compressed lump of metal scrap, including a primary compression cylinder installed at one side of a compression chamber, a primary press plate configured to be moved in a primary compression space by a piston of the primary compression cylinder, secondary compression cylinders installed at opposite sides of the compression chamber, secondary press plates configured to be moved in a secondary compression space by pistons of the respective secondary compression cylinders, a discharge plate disposed at the middle of the secondary compression space, and an opening and closing unit configured to open and close the discharge plate, wherein a direction in which compression is performed by the primary press plate is perpendicular to a direction in which compression is performed by the secondary press plate, and the apparatus further includes at least one core installed at the middle of the secondary compression space in an erected state so that the core is perpendicular to the direction in which compression is performed by the primary press plate and the direction in which compression is performed by the secondary press plate and a core cylinder for advancing and retreating the core to form at least one through hole, and a method of manufacturing a compressed lump of metal scrap using the apparatus for manufacturing the compressed lump of metal scrap. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0015]      FIG. 1  is a longitudinal sectional view showing the construction of a cited invention; 
           [0016]      FIG. 2  is a plan view illustrating the construction of the cited invention; 
           [0017]      FIGS. 3 and 4  are perspective views showing a compressed lump of metal scrap according to the present invention; 
           [0018]      FIG. 5  is a perspective view showing overall construction of an apparatus for manufacturing a compressed lump of metal scrap according to the present invention when viewed from the rear of a cover; 
           [0019]      FIG. 6  is a perspective view showing an operation standby state in a compression chamber of the apparatus for manufacturing the compressed lump of metal scrap according to the present invention; 
           [0020]      FIG. 7  is a bottom view showing an installation state of a core cylinder of the apparatus for manufacturing the compressed lump of metal scrap according to the present invention; 
           [0021]      FIG. 8  is a side view showing a state in which a core of the core cylinder is erected vertically before metal scrap is charged into the compression chamber of the apparatus for manufacturing the compressed lump of metal scrap according to the present invention; 
           [0022]      FIG. 9  is a plan view showing a state in which charging of metal scrap into the compression chamber of the apparatus for manufacturing the compressed lump of metal scrap according to the present invention shown in  FIG. 8  has been completed; 
           [0023]      FIG. 10  is a plan view showing a state in which a primary press plate has been advanced in the apparatus for manufacturing the compressed lump of metal scrap according to the present invention; 
           [0024]      FIG. 11  is a plan view showing a state in which, after the primary press plate had been advanced, secondary press plates have been advanced to a secondary compression space by secondary compression cylinders in the apparatus for manufacturing the compressed lump of metal scrap according to the present invention; 
           [0025]      FIG. 12  is a longitudinal sectional view showing a state in which a core is positioned in a through hole of the compressed lump of metal scrap after primary and secondary compression has been completed in the apparatus for manufacturing the compressed lump of metal scrap according to the present invention; 
           [0026]      FIG. 13  is a plan view showing a state in which the compressed lump of metal scrap is dropped in the apparatus for manufacturing the compressed lump of metal scrap according to the present invention; 
           [0027]      FIG. 14  is a side view showing a state in which the compressed lump of metal scrap is dropped and discharged from the apparatus for manufacturing the compressed lump of metal scrap according to the present invention; 
           [0028]      FIG. 15  is a perspective view showing an embodiment for forming two through holes in the compressed lump of metal scrap in the apparatus for manufacturing the compressed lump of metal scrap according to the present invention; 
           [0029]      FIG. 16  is a longitudinal sectional view of a principal part of the apparatus for manufacturing the compressed lump of metal scrap according to the present invention showing a state in which cores of the core cylinders are positioned in two through holes formed in a compressed lump of metal scrap as the result of primary and secondary compression; 
           [0030]      FIG. 17  is a side view showing discharge of a compressed lump of metal scrap, two through holes of which have been formed by the cores of the core cylinders during primary and secondary compression; 
           [0031]      FIG. 18  is a perspective view showing an embodiment in which a core cylinder is installed at a cover in the apparatus for manufacturing the compressed lump of metal scrap according to the present invention; 
           [0032]      FIG. 19  is a longitudinal sectional view of a principal part of the apparatus for manufacturing the compressed lump of metal scrap according to the present invention shown in  FIG. 18  showing a state in which cores are positioned at portions of a compressed lump of metal scrap at which through holes are to be formed as the result of secondary compression performed by the secondary compression cylinders; 
           [0033]      FIG. 20  is a side view showing discharge of metal scrap compressed according to the embodiment shown in  FIG. 18  through a discharge port; 
           [0034]      FIG. 21  is a perspective view showing another embodiment in which two core cylinders are installed at the cover in the apparatus for manufacturing the compressed lump of metal scrap according to the present invention; 
           [0035]      FIG. 22  is a side sectional view of a principal part of the apparatus for manufacturing the compressed lump of metal scrap according to the present invention showing a state in which cores are positioned in through holes of the compressed lump of metal scrap after primary and secondary compression have been completed according to the embodiment shown in  FIG. 21 ; and 
           [0036]      FIG. 23  is a side view showing discharge of a compressed lump of metal scrap, two through holes of which have been formed according to the embodiment shown in  FIG. 21 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0037]    In one embodiment of the present invention, there is provided an apparatus for manufacturing a compressed lump of metal scrap configured to compress metal scrap by a primary press plate reciprocated in a primary compression space of a compression chamber, which is opened and closed by a cover cylinder so that metal scrap is charged into the compression chamber, by a primary compression cylinder and secondary press plates reciprocated in opposite sides of a secondary compression space of the compression chamber by secondary compression cylinders and to discharge the compressed lump of metal scrap through a discharge port, wherein a direction in which compression is performed by the primary press plate is perpendicular to a direction in which compression is performed by the secondary press plate, and the apparatus includes a core installed at the middle of the secondary compression space in an erected state so that the core is perpendicular to the direction in which compression is performed by the primary press plate and the direction in which compression is performed by the secondary press plate and a core cylinder for reciprocating the core. 
         [0038]    Now, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that the present invention can be easily made by a person having ordinary skill in the art to which the present invention pertains. 
         [0039]    First, a compressed lump  100  of metal scrap according to the present invention is shown in  FIGS. 3 and 4 . 
         [0040]    As shown in these drawings, the compressed lump  100  of metal scrap is formed into a hexahedral body having a predetermined width, length and height according to the present invention. At least one straight through hole  101  is formed in the compressed lump  100  of metal scrap so that the through hole  101  extends through the compressed lump  100  of metal scrap. When the compressed lump  100  of metal scrap is introduced into a blast furnace, therefore, hot air and molten metal can infiltrate into the compressed lump  100  of metal scrap through the through hole  101 . Consequently, it is possible to melt the compressed lump  100  of metal scrap using a small amount of fuel. 
         [0041]    Also, it is possible for an engineer to inspect the interior of the compressed lump  100  of metal scrap through the through hole  101  with the naked eye or using a camera before the compressed lump  100  of metal scrap is introduced into the blast furnace. 
         [0042]    As shown in  FIG. 4 , it is possible to form two through holes  101 . According to circumstances, it is possible to form three or more through holes  101 , the diameter of which is small. The more through holes  101  the compressed lump  100  of metal scrap has, the easier the compressed lump  100  of metal scrap melts. However, it is necessary to additionally install a plurality of cores  201  and a plurality of core cylinders  200 , which are operated in a state in which metal scrap is compressed under high pressure. For this reason, it may be most economical to form only one through hole  101  in consideration of manufacturing equipment costs. Hereinafter, therefore, the present invention will be described based on embodiments of the present invention that form one through hole  101 . 
         [0043]      FIGS. 5 and 6  are perspective views showing the concrete structure of a manufacturing apparatus according to the present invention when viewed in two directions. As shown in these drawings, the manufacturing apparatus according to the present invention includes two primary compression cylinders  110 , which are long. The primary compression cylinders  110  are provided to obtain force sufficient to primarily compress various forms of metal scrap, charged in a compression chamber  140 , during movement of a primary press plate  150  in a primary compression space  300  of the compression chamber  140  from one side of the compression chamber  140 . One, two or three primary compression cylinders  110  may be installed based on kinds and charge amount of metal scrap. 
         [0044]    Also, secondary compression cylinders  120  are installed at opposite sides of a secondary compression space  400  of the compression chamber  140 . A secondary press plate  160  is fixed to a piston of each of the secondary compression cylinders  120  so that the secondary press plate  160  can be advanced toward the middle of the secondary compression space  400 . 
         [0045]    Also, the movement distance of the secondary press plate  160  installed at each side of the compression chamber  140  is the distance by which the secondary press plate  160  moves to the compressed lump  100  of metal scrap formed at the middle of the secondary compression space  400 . Consequently, the stroke of the secondary press plate  160  is short, and therefore, the length of each secondary compression cylinder  120  and the length of the piston thereof are relatively short. Particularly, in the present invention, a core  201  configured to form a through hole  101  penetrating the middle of the compressed lump  100  of metal scrap and a core cylinder  200  to reciprocate the core  201  are installed in addition to the construction of the cited invention. The core  201  is installed perpendicularly to a primary press direction and a secondary press direction. At the same time, the core  201  is installed so as to be erected at the middle of the secondary compression space  400 . In the embodiment of the present invention shown in  FIGS. 5 and 6 , the core cylinder  200 , which advances and retreats the core  201 , is installed under the middle of a discharge plate  502  as shown in  FIG. 7 . A tip  170  having incline planes is formed at the front end of the core  201 . The tip  170  is engaged in a core tip receiving groove  130  of a cover  601  to prevent the core  201  from being deformed due to friction between the core  201  and the metal scrap or stress applied to the core  201 , which is caused by deviation of compression force applied to the metal scrap during primary and secondary compression. 
         [0046]    Also, the manufacturing apparatus according to the present invention further includes the core  201  and the discharge plate  502  installed at the middle of the secondary compression space  400  as described above and an opening and closing unit  500  to open and close the discharge plate  502 . 
         [0047]    The opening and closing unit  500  may include a hydraulic cylinder  504  and a piston in addition to the discharge plate  502 . The opening and closing unit  500  may be configured so that the discharge plate  502 , which is formed of a plate-shaped member having a thickness sufficient to bear pressure, is reciprocated along a guide groove  503  to open and close a discharge port  501 . Alternatively, the discharge plate  502  may be opened and closed by the hydraulic cylinder  504  so as to open and close the discharge port  501 . 
         [0048]    In addition, in this embodiment of the present invention, the discharge plate  502 , the core cylinder  200  and the core  201  are simultaneously reciprocated by the hydraulic cylinder  504  since the core cylinder is installed at the middle of the bottom of the discharge plate  502 . 
         [0049]    Also, in the present invention, the primary and secondary compression cylinders  110  and  120 , the core cylinder  200 , the hydraulic cylinder  504 , a cover cylinder  600  and a locking cylinder  602  are used. Although not shown, a hydraulic pipe is connected to the pistons so that the pistons can be advanced or retreated according to directions in which hydraulic pressure is supplied, which is well known in the art to which the present invention pertains, and therefore, a description thereof will be omitted for the sake of convenience. An operation standby state of the manufacturing apparatus according to the present invention is shown in a side view of  FIG. 8 . 
         [0050]    As shown in  FIG. 8 , the core  201  is erected by the core cylinder  200  before charging of metal scrap, and the cover  601  is opened by the cover cylinder  600 . In this state, metal scrap is charged into the compression chamber  140 . After the primary compression space  300  and the secondary compression space  400  are filled with the metal scrap, the cover cylinder  600  is driven to close the cover  601 . 
         [0051]    A state in which primary compression is ready as described above is shown in a plan view of  FIG. 9 . As shown in  FIG. 9 , the core  201  is advanced by the core cylinder  200 , the primary and secondary press plates  150  and  160  are located at the same position as walls of the compression chamber  140  in a state in which the primary and secondary compression cylinders  110  and  120  are in an operation standby mode, and the hydraulic cylinder  504  is in a state in which the discharge port  510  is closed by the discharge plate  502 . 
         [0052]    In the manufacturing apparatus with the above-stated construction according to the present invention, first, the primary press plate  150  is moved to the end of the primary compression space  300  by the pistons of the primary compression cylinders  110  as shown in  FIG. 10 . Consequently, metal scrap, which has been primarily compressed in the compression chamber  140 , is placed in the secondary compression space  400  in a standby state. The metal scrap wraps the corn  201  while moving to the secondary compression space  400  during primary compression. In this state, the tip  170  of the core positioned at the middle of the secondary compression space  400  is engaged in the core tip receiving groove  130  formed at the cover  601  according to the present invention, thereby preventing the core  201  from being pushed or deformed by the metal scrap moving to the secondary compression space  400  during primary compression. 
         [0053]    Consequently, the metal scrap in the compression chamber  140  is clustered into the secondary compression space  400  while the density of the metal scrap is primarily increased by the primary press plate  150 , and the metal scrap clustered into the secondary compression space  400  is primarily compressed. At the same time, the core  201  is located at a portion of the compression chamber at which a through hole  101  is to be formed in a compressed lump of metal scrap. When the secondary press plates  160  start to compress the metal scrap in the secondary compression space  400  according to operation of the secondary compression cylinders  120  in a state in which the core  201  of the core cylinder  200  extends as described above, the metal scrap starts to be compressed at density higher than that of the primary compression as described above. When the secondary press plates  160  are advanced to a position corresponding to the final dimensions of a compressed lump  100  of metal scrap, the advancement of the secondary press plates  160  is stopped by the secondary compression cylinders  120 . This state is shown in a plan view of  FIG. 11  and a side view of  FIG. 12 . In this state, a through hole  101  is formed in the compressed lump  100  of metal scrap at the portion of the compression chamber at which the core  201  is located so that the through hole  201  surrounds the core  21  as shown in an enlarged sectional view of  FIG. 12 . 
         [0054]    In this state, however, the compressed lump  100  of metal scrap cannot be discharged. According to the present invention, therefore, it is necessary to retreat the core  201  so that the tip  170  of the core  201  is placed at a lower position than the surface of the discharge plate  502  and the compression chamber  140  as shown in  FIGS. 13 and 14 . 
         [0055]    To this end, the core cylinder  200  is driven. As a result, the core  201  is retreated, and then the primary compression cylinders  110  and the secondary compression cylinders  120  are retreated to their original positions. In addition, the hydraulic cylinder  504  of the opening and closing unit  500  is driven to reciprocate the discharge plate  502  along the guide groove  503  so that the discharge port  501  is opened with the result that the compressed lump  100  of metal scrap falls through the discharge port  501  and is carried outside by a conveyor. 
         [0056]    Subsequently, the hydraulic cylinder  504  of the opening and closing unit  500  is driven to move the discharge plate  502  so that the discharge plate  502  closes the discharge port  501 . The core  201  is moved upward by the core cylinder  200 , and a piston  603  of the locking cylinder  602  is separated from a locking hole  604 , and then the cover cylinder  600  is driven to lift the cover  601  so that the manufacturing apparatus is in state as shown in  FIG. 8 . Subsequently, metal scrap is charged into the compression chamber, the primary compression cylinders  110  are driven to resume primary compression with the respect to the metal scrap through the primary press plate  150 . In this way, the process of manufacturing the compressed lump  100  of metal scrap is continuously repeated. 
         [0057]    In addition, according to the present invention, as shown in  FIG. 15 , two core cylinders  200  are installed at the discharge plate  502  so that two cores  201  can be advanced and retreated, and tips  170  formed at the upper ends of the two cores  201  are configured to be engaged in two core tip receiving grooves  130  formed at the bottom of the cover  601   
         [0058]    In this state, metal scrap is charged into the compression chamber  140 , and primary and secondary compression is carried out through the process shown in  FIGS. 9 to 11 . As a result, a compressed lump  100  of metal scrap is finally formed in a state in which two through holes  101  are formed in the compressed lump  100  of metal scrap at the portions of the compression chamber at which the two cores  201  are located at the middle of the secondary compression space  400  as shown in  FIG. 16 . Subsequently, the hydraulic cylinder  504  of the opening and closing unit  500  is driven to retreat the discharge plate  502  along the guide groove  503  so that the discharge port  501  is opened. As a result, as shown in  FIG. 17 , the compressed lump  100  of metal scrap falls and is discharged through the discharge port  501 . 
         [0059]    Meanwhile, the core  201  and the core cylinder  200  may be installed at other positions different from the discharge plate  502 . A concrete example thereof is shown in  FIG. 18 . As shown in  FIG. 18 , the core  201  and the core cylinder  200  are installed at the cover  601  instead of the discharge plate  502 . In this embodiment, it is necessary to locate the core tip receiving groove  130  at the middle of the discharge plate  502 . 
         [0060]    In this embodiment, as shown in  FIG. 18 , the cover  601  is opened to open the compression chamber  140 . In this state, metal scrap is charged into the compression chamber  140 , the cover  601  is closed, and primary and secondary compression is carried out through the process shown in  FIGS. 9 to 11 . In this embodiment, in order to easily achieve downward movement of the core  201  of the core cylinder  200  installed at the cover  610  moving downward to the secondary compression space  400  during charge of the metal scrap, it is necessary for the core  201 , which will form a through hole  101  in the compressed lump  100  of metal scrap, to be placed at a predetermined position before compression so that the metal scrap is not placed at the middle of the secondary compression space  400 . 
         [0061]    In this embodiment, metal scrap is charged, the cover  601  is closed, and the core cylinder  200  is driven to move the core  201  downward. At this time, the tip  170  of the core  201  is engaged in the core tip receiving groove  130  formed at the middle of the discharge plate  502  with the result that the core  201  is stably fixed. 
         [0062]    After location of the core  201  to form the through hole  101  in the compressed lump  100  of metal scrap has been completed as described above, primary and secondary compression is carried out through the above process to compress the metal scrap so that the metal scrap has a target density. As a result, the core  201  of the core cylinder  200  fixed to the cover  601  is located in the through hole  101  of the compressed lump  100  of metal scrap as shown in  FIG. 19 . 
         [0063]    In this state, the core cylinder  200  is driven to move the core  201  upward as shown in  FIG. 20 . As a result, the core  201  is separated from the through hole  101  of the compressed lump  100  of metal scrap. Subsequently, the hydraulic cylinder  504  of the opening and closing unit  500  is driven to reciprocate the discharge plate  502  along the guide groove  503  with the result that the discharge port  501  is opened. 
         [0064]    Consequently, the compressed lump  100  of metal scrap, which is a weight body, falls and is discharged through the discharge port  501 . 
         [0065]    In the above embodiment, the core  201  and the core cylinder  200  are installed at the cover  601  instead of the discharge plate  502 , and the core tip receiving groove  130  is formed at the discharge plate  502  as shown in  FIG. 18 . In another embodiment, on the other hand, a plurality of cores  201  and a plurality of core cylinders  200  may be installed at the cover  601 , and a plurality of core tip receiving grooves  130  may be formed at the discharge plate  502 , as shown in  FIG. 21 , to form a plurality of through holes  101  in the compressed lump  100  of metal scrap. That is, in this embodiment, the cover  601  is opened to open the compression chamber  140 , metal scrap is charged into the compression chamber  140 , the cover  601  is closed, and the core cylinders  200  are driven to move the cores  201  downward. At this time, the tips  170  of the respective cores  201  are engaged in the core tip receiving grooves  130  formed at the discharge plate  502  with the result that the cores  201  are stably fixed. 
         [0066]    After location of the cores  201  to form the through holes  101  in the compressed lump  100  of metal scrap has been completed as described above, primary and secondary compression is carried out through the above process to compress the metal scrap so that the metal scrap has a target density. As a result, the through holes  101  are formed in the compressed lump  100  of metal scrap by the cores  201  of the core cylinders  200  fixed to the cover  601  as shown in  FIG. 22 . 
         [0067]    In this state, the core cylinders  200  are driven to move the cores  201  upward as shown in  FIG. 23 . As a result, the cores  201  are separated from the through holes  101  of the compressed lump  100  of metal scrap. Subsequently, the hydraulic cylinder  504  of the opening and closing unit  500  is driven to reciprocate the discharge plate  502  along the guide groove  503  with the result that the discharge port  501  is opened. Consequently, the compressed lump  100  of metal scrap, which is a weight body, falls and is discharged through the discharge port  501 . 
         [0068]    In the present invention as described above, the core  201  is located at the portion of the compression chamber at which the through hole  101  is to be formed in the compressed lump of metal scrap before the metal scrap is compressed under high pressure. Consequently, it is possible to form the through hole  101  in the compressed lump  100  of metal scrap, which is compressed with high density and thus cannot be processed except melting, while load is not applied to the core  201  and the relevant components. 
         [0069]    In case of punching or drilling the compressed lump  100  of metal scrap using a drilling machine to form the through hole  101  in the compressed lump  100  of metal scrap, as can be commonly thought by those skilled in the art to which the present invention pertains, needs massive equipment, and high-priced materials for punching or drilling are frequently damaged or consumed. 
         [0070]    In case of forming the through hole according to the present invention, on the other hand, the core is located at the portion of the compression chamber at which the through hole is to be formed in the compressed lump of metal scrap before the metal scrap is compressed under high pressure. Consequently, massive equipment is not needed, and high-priced materials for punching or drilling are not damaged or consumed, thereby greatly improving economy and operation efficiency. 
         [0071]    Meanwhile, in the present invention, the discharge plate  502  is installed in the middle of the secondary compression space  400 , and the opening and closing unit  500  using the hydraulic cylinder  504  to reciprocate the discharge plate  502  is disposed under the discharge plate  502 . Of course, however, various kinds of well-known opening and closing devices may be selectively applied as needed. 
         [0072]    Hereinafter, a method of manufacturing a compressed lump of metal scrap according to the present invention will be described with the accompanying drawings. 
         [0073]    The method of manufacturing the compressed lump of metal scrap according to the present invention includes a step of charging metal scrap into the compression chamber  140 , a step of performing a locking operation to close the cover  601  using the cover cylinder  600  and to drive the locking cylinder  602  so that the piston  603  extends to be fitted into the locking hole  604 , a primary compression step of primarily compressing the metal scrap charged in the compression chamber  140  using the primary compression cylinders  110 , a secondary compression step of secondarily compressing the primarily compressed metal scrap using the secondary compression cylinders  120 , a discharge step of discharging a compressed lump  100  of metal scrap, compressed with target density through the secondary compression, through the discharge port, and a step of opening the cover  601  according to the operation of the cover cylinder  600  so that metal scrap can be charged into the compression chamber  140  again, the above steps being repeatedly carried out to repeatedly compress metal scrap, wherein the method of manufacturing the compressed lump of metal scrap according to the present invention further includes a space occupation step of vertically erecting the core  201  at the middle of the secondary compression space  400  so that the core  201  is located at a portion of the compression chamber at which a through hole is to be formed in the compressed lump of metal scrap before the primary compression step is carried out, a through hole forming step of maintaining the region of the secondary compression space occupied by the core  201  to form a through hole  101  in the compressed lump  100  of metal scrap while performing secondary compression using the secondary compression cylinders  120  after the primary compression is completed, and a core retreating step of separating the core  201  from the through hole to discharge the compressed lump  100  of metal scrap, compressed with target density, after the through hole  101  is formed in the compressed lump  100  of metal scrap. 
         [0074]    Also, in realizing the method of manufacturing the compressed lump of metal scrap as described above, the core cylinder  200  to form the through hole  101  may be installed at the middle of the discharge plate  502 , which is opened and closed by the hydraulic cylinder  504  of the opening and closing unit  500  to open and close the discharge port  501 , as shown in  FIGS. 5 to 14 . Hereinafter, a method of manufacturing a compressed lump of metal scrap through the above-stated construction will be described in more detail. 
         [0075]    The method of manufacturing the compressed lump of metal scrap according to the present invention includes a step of charging metal scrap into the primary compression space  300  and the secondary compression space  400  of the compression chamber  140  and a step of performing a locking operation to close the cover  601  using the cover cylinder  600  and to drive the locking cylinder  602  so that the piston  603  extends to be fitted into the locking hole  604 , as shown in  FIG. 9 , a primary compression step of primarily compressing the metal scrap charged in the compression chamber  140  using the primary compression cylinders  110 , as shown in  FIG. 10 , a secondary compression step of secondarily compressing the primarily compressed metal scrap using the secondary compression cylinders  120 , as shown in  FIGS. 11 and 12 , and a discharge step of discharging a compressed lump of metal scrap, compressed with target density through the secondary compression, through the discharge port and a step of opening the cover according to an opening operation of the cover cylinder  600  so that metal scrap can be charged into the compression chamber  140  again, as shown in  FIGS. 13 and 14 , the above steps being repeatedly carried out to repeatedly compress metal scrap, wherein the method of manufacturing the compressed lump of metal scrap according to the present invention further includes a space occupation step of upwardly extending the core  201  using the core cylinder  200  installed at the middle of the discharge plate  502  to close the discharge port  501  so that the core  201  is located at the middle of the secondary compression space  400  before the step of charging the metal scrap into the compression chamber  140  and the step of closing the cover  601  are carried out, an occupied space maintaining step of maintaining the middle of the secondary compression space occupied by the core  201  at the primary and secondary compression steps, a through hole forming step of maintaining the region of the secondary compression space occupied by the core  201  to form a through hole  101  in the compressed lump  100  of metal scrap after primary and secondary compression is completed, and a core retreating step of downwardly moving the core  201  to a position lower than the height of the discharge plate  502  using the core cylinder  200  so that the core  201  is separated from the compressed lump  100  of metal scrap to discharge the compressed lump  100  of metal scrap, compressed with target density, after the through hole  101  is formed in the compressed lump  100  of metal scrap. Also, a method of manufacturing the compressed lump of metal scrap according to another embodiment of the present invention may include a space occupation step of downwardly extending the core  201  using the core cylinder  200  so that the core  201  is located at the middle of the secondary compression space  400  before or after closing the cover  610  at which the core cylinder  200  is installed, an occupied space maintaining step of maintaining the middle of the secondary compression space occupied by the core  201  at the primary and secondary compression steps, a through hole forming step of maintaining the region of the secondary compression space occupied by the core  201  to form a through hole  101  in the compressed lump  100  of metal scrap after primary and secondary compression is completed, and a core retreating step of upwardly moving the core  201  to a position higher than the bottom of the cover  601  using the core cylinder  200  so that the core  201  is separated from the compressed lump  100  of metal scrap to discharge the compressed lump  100  of metal scrap, compressed with target density, after the through hole  101  is formed in the compressed lump  100  of metal scrap. Meanwhile, in the embodiment in which the core  201  is upwardly moved so that the core  201  can be placed at a higher position than the discharge plate  502  during the manufacturing process according to the present invention, the tip of the core  201  is fitted in the core tip receiving groove  130  formed at the bottom of the cover  601 , and in the embodiment in which the core  201  is downwardly moved so that the core  201  can be placed at a lower position than the cover  601  during the manufacturing process according to the present invention, the tip of the core  201  is fitted in the core tip receiving groove  130  formed at the middle of the discharge plate  502 . As a result, the core  201  is securely and stably fixed, and therefore, it is possible to efficiently bear friction between the core  201  and the metal scrap or stress applied to the core  201  during primary and secondary compression, thereby minimizing wear of the core or damage to the core. 
         [0076]    Also, in the present invention, a plurality of through holes may be formed so that the compressed lump of metal scrap can be more easily melted when the compressed lump of metal scrap is introduced into a blast furnace. To this end, a plurality of core cylinders  200  may be installed at the discharge plate  502  as shown in  FIGS. 15 to 17 , or a plurality of core cylinders  200  may be installed at the cover  601  as shown in  FIGS. 21 to 23 . In each case, a plurality of core tip receiving grooves  130  is formed at the bottom of the cover  601  or the top of the discharge plate  502 . 
         [0077]    Furthermore, in the present invention, well-known elements may be added or changed based on kinds of metal scrap or conditions of a manufacturing field where the apparatus for manufacturing the compressed lump of metal scrap is installed. Also, the technical characteristics of the present invention are not limited to the above-described embodiments and may be variously changed within the gist and concept intended by the present invention. 
         [0078]    As apparent from the above description, a compressed lump of metal scrap manufactured according to the present invention has one or more through holes. When the compressed lump of metal scrap is introduced into a blast furnace, therefore, molten metal can infiltrate into the middle of the compressed lump of metal scrap through the through holes as well as the circumference of the compressed lump of metal scrap. Consequently, it is possible to rapidly melt the compressed lump of metal scrap at a speed equivalent to the speed at which a small-sized compressed lump of metal scrap is melted, thereby greatly reducing energy necessary to manufacture steel products. 
         [0079]    Also, in the manufacturing apparatus according to the present invention, the metal scrap is primarily compressed around the core during the low-density compression process of primarily compressing the metal scrap charged in the compression chamber, and the metal scrap is secondarily compressed through the high-density compression process with the result that the through hole is formed in the compressed lump of metal scrap. Consequently, it is possible to minimize friction between the core and the metal scrap and stress applied to the core during the compression processes. 
         [0080]    Particularly, in the present invention, the length of the core extending in the compression chamber to form the through hole in the compressed lump of metal scrap is configured to be equivalent to the length of the actual through hole of the compressed lump of metal scrap. Consequently, the length of the core is minimized, and therefore, bending stress applied to the core due to density deviation of the metal scrap during primary and secondary compression is minimized. Furthermore, since the length of the core is short, the deformation of the core is minimized, and therefore, durability of the core is greatly improved, thereby achieving stable operation of the core and increasing lifespan of the core. 
         [0081]    In addition, in the present invention, metal scrap is charged into the compression chamber in a state in which the core is vertically erected in the compression chamber, and then primary and secondary compression is carried out. Consequently, the metal scrap is prevented from wedging into the core, the cover and the bottom of the compression chamber irrespective of shapes or kinds of the metal scrap, thereby achieving smooth operation.