BACKUP STRUCTURE OF RISE TUBE OR DOWN COMER OF VACUUM DEGASSING APPARATUS

摘要

A backup structure of the rise tube or the down comer of a vacuum degassing apparatus in which a structure for releasing elongation of a refractory brick due to thermal expansion downward is prevented from being damaged by elongation of the refractory brick, a vacuum degassing apparatus employing that backup structure, and vacuum degassing method of molten glass employing the vacuum degassing apparatus. In a vacuum degassing apparatus comprising a rise tube, a vacuum degassing tank and a down comer, the backup structure of the rise tube or the down comer of the vacuum degassing apparatus constituted by arranging refractory bricks around the rise tube or the down comer made of platinum or a platinum alloy, characterized in that a thermal expansion release member composed of a material selected from a metal material or a ceramic material having creep strength (JIS Z2271:1993) of 35 MPa or above at 760°C is arranged above the refractory bricks.