Pulling-up-type continuous casting apparatus and pulling-up-type continuous casting method

Abstract

A pulling-up-type continuous casting apparatus according to an aspect of the present invention includes a molten-metal holding furnace that holds molten metal, a shape defining member configured to define a cross-sectional shape of a hollowed cast-metal article to be casted as held molten metal drawn from the molten-metal surface passes through the shape defining member, a cooling unit that cools the held molten metal by blowing a cooling gas on an inner peripheral surface of the hollowed cast-metal article near an solidification interface, the drawn molten metal continuously extending to the cast-metal article through the solidification interface, and a blower unit that blows air to a negative pressure area formed in a space between a flow path through which the cooling gas blown from the cooling unit flows and a top surface of the shape defining member.

What is claimed is: 
     
         1 . A pulling-up-type continuous casting apparatus comprising:
 a holding furnace that holds molten metal;   a shape defining member disposed above a molten-metal surface of the molten metal, the shape defining member being configured to define a cross-sectional shape of a hollow cast-metal article to be casted as the molten metal drawn from the molten-metal surface passes through the shape defining member; and   a cooling unit that cools the molten metal drawn from the molten-metal surface by blowing a cooling gas on an inner peripheral surface of the hollow cast-metal article near an solidification interface, the drawn molten metal continuously extending to the hollow cast-metal article through the solidification interface, wherein   the pulling-up-type continuous casting apparatus further comprises a blower unit that blows air to a negative pressure area formed in a space between a flow path through which the cooling gas blown from the cooling unit flows and a top surface of the shape defining member.   
     
     
         2 . The pulling-up-type continuous casting apparatus according to  claim 1 , wherein an air blowing hole of the blower unit is disposed above the cooling unit inside the hollow cast-metal article and blows air toward the negative pressure area located below the air blowing hole. 
     
     
         3 . The pulling-up-type continuous casting apparatus according to  claim 1 , wherein the air blowing hole of the blower unit is disposed in a component adjacent to the negative pressure area and opened toward the negative pressure area. 
     
     
         4 . The pulling-up-type continuous casting apparatus according to  claim 1 , further comprising a pressure sensor that measures a pressure of the negative pressure area, wherein
 the blower unit blows air at a flow rate according to a measurement result of the pressure sensor.   
     
     
         5 . A pulling-up-type continuous casting method for casting a hollow cast-metal article by drawing molten metal held in a holding furnace from a molten-metal surface of the molten metal and making the drawn molten metal pass through a shape defining member, the shape defining member being configured to define a cross-sectional shape of the hollow cast-metal article, the pulling-up-type continuous casting method comprising:
 a step of cooling the molten metal drawn from the molten-metal surface by blowing a cooling gas on an inner peripheral surface of the hollow cast-metal article near an solidification interface, the drawn molten metal continuously extending to the hollow cast-metal article through the solidification interface; and   a step of blowing air to a negative pressure area formed in a space between a flow path through which the blown cooling gas flows and a top surface of the shape defining member.