MOLTEN GLASS VACUUM DEGASSING APPARATUS, VACUUM DEGASSING METHOD, AND APPARATUS AND METHOD FOR MANUFACTURING GLASS PRODUCT

摘要

It is an object of the present invention to provide a vacuum degassing apparatus wherein even if bubbles of molten glass come into contact with an inner wall of an upper space of a vacuum degassing vessel to produce a molten glass flowing along the inner wall, such a molten glass can be discharged to the outside of the vacuum degassing vessel. The present invention is characterized in that the vacuum degassing vessel comprises a bottom wall portion, a side wall portion and a ceiling portion, that define a molten glass-accommodating portion and an upper space, the upper space is constituted by a combination of a plurality of crown refractories; among the plurality of crown refractories constituting the upper space, a crown refractory provided on an upper face of such a soldier refractory is disposed so that a lower portion of a face of the crown refractory facing to the inside of the vacuum degassing vessel is positioned more outside than the position of a molten-glass-contact surface of the soldier refractory, a storage portion for molten glass is formed between the upper face of the soldier refractory and a lower portion of the crown refractory disposed on the soldier refractory; and that a discharge path for molten glass communicating with the storage portion and the outside of the vacuum degassing vessel is formed, in a portion where the soldier refractory is joined with the crown refractory.