Schott Ag

Dirk Gohlke

Joerg Witte

Franz Ott

Frank-Thomas Lentes

Rainer Erwin Eichholz

Klaus-Dieter Duch

Jörg Witte

Frank Karetta

Wolfgang Muench

Allen Jakway

The regionally coated noble metal element used in glass production has an uncoated region for contacting a glass melt and an H-impervious layer or an H-impervious and O-impervious layer on a side opposite from the uncoated region, which has a layer thickness &#x2267;1 mm, is heat-resistant, and is either liquid or solid. This layer is made from at least one glass or glass mixture, an at least partly crystallized glass or a ceramic material. The coated noble metal element can be a Danner channel, a Vello draw head, an A-draw head, a Vello needle, a drawdown needle, a discharge ring or a Danner blowpipe. A process for coating a noble metal element to produce the regionally coated noble metal element is also described.

Coated noble metal elements for glass production

The coated noble metal element used in glass manufacture, such as a noble metal pipe, has an uncoated side that contacts a glass melt and an H-impervious layer or an H-impervious and O-impervious layer, which is provided on a side opposite from the uncoated side. The H-impervious layer or H-impervious and O-impervious layer is heat-resistant and is liquid or solid. In one process for providing the layer on the noble metal element an empty space between the noble metal element and a ceramic insulating jacket is filled with a coating material, and then the coating material is melted so that it wets a surface of the noble metal element. The coating material can include glass cullet, crushed glass or glass powder or is a mixture of crushed glass and ground ceramic material.

Coated metal elements for producing glass

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 H-impervious layer or an H-impervious and O-impervious layer. The H-impervious layer or H-impervious and O-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.

Coated metal element used for producing glass

The apparatus for reduced-pressure refining of a glass melt includes a refining bank formed so that a reduced pressure is generated by a glass flow in it. The refining bank has a component, which is made from a refractory metal or refractory alloy acting as glass-contact material. The refractory metal or alloy contains molybdenum, tungsten, tantalum, and/or hafnium. The device of the present invention includes a protective gas reservoir for a protective gas and an automatically operating valve connecting the reservoir with the refining bank so that an inner side of the component that would otherwise be exposed when a pressure rise or a falling glass melt column occurs is protected from oxidation by the protective gas. A process for using the device during refining of the glass melt is also part of the invention.

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Mainz, Germany

Dirk Gohlke