Method for defoaming molten glass, apparatus for defoaming molten glass, method for producing molten glass, apparatus for producing molten glass, method for producing glass product, and apparatus for producing glass product

摘要

To provide a vacuum-degassing method and a vacuum degassing apparatus excellent in the effect of vacuum-degassing molten glass, more specifically, a method for vacuum-degassing molten glass and a vacuum degassing apparatus, capable of effectively suppressing formation of reboil bubbles. A method for vacuum-degassing molten glass, which comprises melting glass materials to be silicate glass and passing the resulting molten glass in a flow passage in a vacuum degassing vessel, the interior of which is maintained in a reduced pressure state, to vacuum-degas the molten glass, wherein vacuum-degassing is carried out under conditions satisfying the following formula (1) at a bottom portion of the vacuum degassing vessel: SS = pSO 2 / P abs 2.0 wherein SS is the supersaturation degree of SO 2 in the molten glass, pSO 2 is the partial pressure (Pa) of SO 2 , and P abs is the pressure (Pa) at the bottom portion of the glass flow passage of the vacuum degassing vessel.