Abstract: A flange (13) for use in direct resistance heating of a glass-carrying vessel (10), such as a finer, is provided. The flange comprises a plurality of electrically-conductive rings which include an innermost ring (140) which is joined to the vessel's exterior wall (12) during use of the flange and an outermost ring (150) which receives electrical current during use of the flange. The innermost ring (140) comprises a high-temperature metal which comprises at least 80% platinum and the outermost ring (150) comprises at least 99.0% nickel. This combination of materials both increases the reliability of the flange and reduces its cost. In certain embodiments, the flange can also include one or more rings (190) composed of a platinum-nickel alloy which has a lower thermal conductivity than platinum or nickel and thus can serve to reduce heat loss through the flange.

Abstract: Stirring apparatuses for stirring molten glass are disclosed. The method includes stirring a molten glass with a stirrer comprising a layer containing at least about 50% iridium. An apparatus comprising an iridium-containing layer is also presented. In one embodiment, an apparatus for stirring molten glass includes a cylinder comprising a bore. A stirrer may be disposed in the bore. The stirrer may include a platinum or platinum alloy shaft coaxial with the cylinder. A plurality of impellers may project radially from the shaft into close proximity of a wall of the cylinder. Each impeller may include an arcuate distal end portion farthest from the shaft. The distal end portion of each impeller consists of iridium or an iridium alloy and the remainder of the impeller consists of platinum or a platinum alloy. The stirring apparatuses reduce metal loss from the refractory metal of the stirring apparatus.

Abstract: Stirring apparatuses for stirring molten glass are disclosed. The method includes stirring a molten glass with a stirrer comprising a layer containing at least about 50% iridium. An apparatus comprising an iridium-containing layer is also presented. In one embodiment, an apparatus for stirring molten glass includes a cylinder comprising a bore. A stirrer may be disposed in the bore. The stirrer may include a platinum or platinum alloy shaft coaxial with the cylinder. A plurality of impellers may project radially from the shaft into close proximity of a wall of the cylinder. Each impeller may include an arcuate distal end portion farthest from the shaft. The distal end portion of each impeller consists of iridium or an iridium alloy and the remainder of the impeller consists of platinum or a platinum alloy. The stirring apparatuses reduce metal loss from the refractory metal of the stirring apparatus.

Abstract: A flange (13) for use in direct resistance heating of a glass-carrying vessel (10), such as a finer, is provided. The flange comprises a plurality of electrically-conductive rings which include an innermost ring (140) which is joined to the vessel's exterior wall (12) during use of the flange and an outermost ring (150) which receives electrical current during use of the flange. The innermost ring (140) comprises a high-temperature metal which comprises at least 80% platinum and the outermost ring (150) comprises at least 99.0% nickel. This combination of materials both increases the reliability of the flange and reduces its cost. In certain embodiments, the flange can also include one or more rings (190) composed of a platinum-nickel alloy which has a lower thermal conductivity than platinum or nickel and thus can serve to reduce heat loss through the flange.

Abstract: A flange (13) for use in direct resistance heating of a glass-carrying vessel (10), such as a finer, is provided. The flange comprises a plurality of electrically-conductive rings which include an innermost ring (140) which is joined to the vessel's exterior wall (12) during use of the flange and an outermost ring (150) which receives electrical current during use of the flange. The innermost ring (140) comprises a high-temperature metal which comprises at least 80% platinum and the outermost ring (150) comprises at least 99.0% nickel. This combination of materials both increases the reliability of the flange and reduces its cost. In certain embodiments, the flange can also include one or more rings (190) composed of a platinum-nickel alloy which has a lower thermal conductivity than platinum or nickel and thus can serve to reduce heat loss through the flange.

Abstract: Stirring apparatuses for stirring molten glass are disclosed. The method includes stirring a molten glass with a stirrer comprising a layer containing at least about 50% iridium. An apparatus comprising an iridium-containing layer is also presented. In one embodiment, an apparatus for stirring molten glass includes a cylinder comprising a bore. A stirrer may be disposed in the bore. The stirrer may include a platinum or platinum alloy shaft coaxial with the cylinder. A plurality of impellers may project radially from the shaft into close proximity of a wall of the cylinder. Each impeller may include an arcuate distal end portion farthest from the shaft. The distal end portion of each impeller consists of iridium or an iridium alloy and the remainder of the impeller consists of platinum or a platinum alloy. The stirring apparatuses reduce metal loss from the refractory metal of the stirring apparatus.

Abstract: Disclosed is a thermocouple circuit that exhibits reduced levels of thermocouple drift. The thermocouple is generally comprised of first and second thermoelectric elements formed of first and second thermoelectric materials, respectively. The first and second thermoelectric elements are coupled to an electrically conductive substrate through intermediate first and second tab elements, respectively. The first and second tab elements are preferably formed of the respective first and second thermoelectric materials, and coupled to the substrate in a spaced apart configuration such that the first and second tab elements, are not physically coupled one to the other. Also disclosed are systems and methods for the preparation and use of the thermocouple circuits disclosed herein.

Abstract: A flange (13) for use in direct resistance heating of a glass-carrying vessel (10), such as a finer, is provided. The flange comprises a plurality of electrically-conductive rings which include an innermost ring (140) which is joined to the vessel's exterior wall (12) during use of the flange and an outermost ring (150) which receives electrical current during use of the flange. The innermost ring (140) comprises a high-temperature metal which comprises at least 80% platinum and the outermost ring (150) comprises at least 99.0% nickel. This combination of materials both increases the reliability of the flange and reduces its cost. In certain embodiments, the flange can also include one or more rings (190) composed of a platinum-nickel alloy which has a lower thermal conductivity than platinum or nickel and thus can serve to reduce heat loss through the flange.

Abstract: Disclosed is a thermocouple circuit that exhibits reduced levels of thermocouple drift. The thermocouple is generally comprised of first and second thermoelectric elements formed of first and second thermoelectric materials, respectively. The first and second thermoelectric elements are coupled to an electrically conductive substrate through intermediate first and second tab elements, respectively. The first and second tab elements are preferably formed of the respective first and second thermoelectric materials, and coupled to the substrate in a spaced apart configuration such that the first and second tab elements, are not physically coupled one to the other. Also disclosed are systems and methods for the preparation and use of the thermocouple circuits disclosed herein.

Abstract: A method of reducing metal loss from the refractory metal of a stirring apparatus for stirring molten glass, and the apparatus therefore are disclosed. The method includes stirring a molten glass with a stirrer comprising a layer containing at least about 50% iridium. An apparatus comprising an iridium-containing layer is also presented. The apparatus may have surfaces adapted to reduce a flow of molten glass over the surface, thereby forming a layer of stagnant, or quasi-stagnant glass on the surface of the stirrer. Adaptations may include grooves in a surface of the stirrer impeller blades, or holes through the stirrer impeller blades.