Coated metal element used for producing glass

摘要

The regionally coated noble metal element for use in glass production has an uncoated region for contacting a glass melt and a side opposite from the uncoated region is provided with an H₂-impervious layer or an H₂-impervious and O₂-impervious layer. The H₂-impervious layer or H₂-impervious and O₂-impervious layer has a thickness greater than or equal to 1 mm, is heat-resistant, liquid, or solid. This layer is made from at least one partly or completely crystallized glass or a glass mixture or a ceramic material. Processes for coating the noble metal element are also described. The coated metal elements can be an electrode in a distributor, a channel or melting tank, a pipe for conducting and conditioning glass melts, a shaping tool for producing pipes and rods or a jacketed platinum tube for direct heating of bottom outlets, transport equipment or charging organs, an agitator, a pipe-drawing head, a feeder head, a plunger in gob feeders, drawing tanks and drawing lips for flat glass production and fining chambers.