PURPOSE: To prevent the intrusion of the water contained in a refractory material on a furnace wall or condensing on the surface of said material in a molten metal by passing the gas for pressurization filled in the space in the furnace through the refractory material of the furnace wall and the evacuation conduit in contact with said material.
CONSTITUTION: Air permeable refractory materials 2, 2a are lined on furnace walls 1, 1a consisting of an airtight shell to form lower and upper furnace bodies 3, 4. Pressurized gas is fed through a pressurization conduit 11 into a space 10 in the furnace and a molten metal A is cast through a stoke 7 into a casting mold 6. The gas in the space 10 is passed through the clearance of the material 2 through an evacuation conduit 13 opening on the bottom surface of the material 2 after solidification of the casting and is discharged to the outside of the furnace. Always the steady gaseous flow is thus generated in the refractory material during the pressure increase and decrease cycle in the stage of casting and the pressure of the molten metal is maintained higher than the pressure in the refractory material. The condensation of the water owing to the stagnation of the gas on the inside surface of the furnace wall and the generation of pinholes in a casting on account of such condensation are thus prevented.
SHIMIZU KUNIO
ASAHARA TAKAO
| JP36008155A |