Abstract: A vacuum degassing apparatus for molten glass according to the present invention comprises a vacuum housing where a vacuum is created; a vacuum degassing vessel housed in the vacuum housing to degas the molten glass; an introduction device communicated to the vacuum degassing vessel so as to introduce untreated molten glass into the vacuum degassing vessel, or preferably an uprising pipe; and a discharge device to discharge treated molten glass from the vacuum degassing vessel, or preferably a downfalling pipe. In the apparatus, at least a portion of at least one of the vacuum degassing vessel, the uprising pipe and the downfalling pipe that directly contact with the molten glass is constituted by refractory material having a porosity of not greater than 5%. The apparatus can increase quantity of flow of the molten glass and consequently a degassing throughput of the molten glass in comparison with prior art, having the same size and the same pressure loss.

Abstract: A vacuum degassing apparatus for molten glass includes a vacuum housing where a vacuum is created; a vacuum degassing vessel housed in the vacuum housing to degas the molten glass; an introduction device communicated to the vacuum degassing vessel so as to introduce untreated molten glass into the vacuum degassing vessel, or preferably an uprising pipe; and a discharge device to discharge treated molten glass from the vacuum degassing vessel, or preferably a downfalling pipe. In the apparatus, at least a portion of at least one of the vacuum degassing vessel, the uprising pipe and the downfalling pipe that directly contact the molten glass is constituted by refractory material having a porosity of not greater than 5%. The apparatus can increase quantity of flow of the molten glass and consequently a degassing throughput of the molten glass, having the same size and the same pressure loss.