Method and device for refining a glass melt using negative pressure

A process for reduced-pressure refining of a glass melt in a reduced-pressure apparatus comprising a refining bank for the glass melt, a riser for supplying the glass melt to the refining bank, and a downpipe for discharge of the glass melt from the refining bank, wherein said refining bank, said riser, and/or said downpipe comprises at least one component made from at least one refractory metal or a refractory metal alloy acting as glass-contact material, said at least one refractory metal is selected from the group consisting of molybdenum, tungsten, tantalum, and hafnium, and said refractory metal alloy contains at least one of said molybdenum, said tungsten, said tantalum, and said hafnium, so that said at least one component contacts the glass melt;

• said process comprising the steps of:
• a) feeding a glass melt to be refined to the refining bank via the riser;
• b) generating a reduced pressure in the refining bank by means of a glass flow in the refining bank;
• and
• c) supplying a protective gas from a protective reservoir via an automatic connection to protect an inner side of the at least one component from oxidation when a pressure rise or a fall of a glass melt column occurs.