Gas permeable well nozzle.

摘要

The invention is directed to a gas permeable well nozzle for use in a metallurgical vessel such as in a well block of a tundish, ladle or like vessel. The well nozzle (40) is generally cylindrical in shape and includes a gas permeable refractory member (42) having an axial bore (44) therethrough. The gas permeable member is preferably formed of a pressed and fired ceramic refractory material having a high resistance to molten metal erosion such as alumina, zirconia or magnesia, present either as a single phase or as a carbon bonded system. A castable refractory member (46) is positioned around the outside of the gas permeable portion and defines an open gas annulus (48) therebetween. The castable portion contacts the gas permeable portion to form upper and lower gas impermeable joints around the gas annulus. A metal can (50) is preferably positioned around the castable member and includes a gas fitting (52) which communicates with a gas inlet channel (49) formed in the castable portion to permit introduction of pressurized inert gas therethrough. The major refractory constituents of the gas permeable member and the castable member are preferably identical so as to provide matched thermal expansion rates and thus lessen the opportunity for thermal induced cracking along the gas impermeable joints between the two members. <IMAGE>