Abstract: Stirrer (1) for stirring molten glass (16), whereby the stirrer (1) comprises —a shaft (2) having a tip (4) and having a central longitudinal axis (L), and —one or more inner stirrer blades (5,6) which are attached to the shaft (2), and —one or more outer stirrer blades (7,8) which are attached to the shaft (2), whereby the inner stirrer blades (5,6) are attached closer to the shaft (2) than the outer stirrer blades (7,8), whereby, when considering the stirrer in a cylindrical coordinate system (11), both the one or more inner stirrer blades (5,6) as well as the one or more outer stirrer blades (7,8) are disposed at an angle (?, ?) to the central longitudinal axis (L), whereby said angle (?, ?) is between 0° and 90° not including these values, and are disposed having a least a blade section with a normal vector (N, P, Q, R), on the side directed towards the tip (4), with an angular component (NA, PA, QA, RA).

Abstract: Stirrer (1) for stirring molten glass (16), whereby the stirrer (1) comprises—a shaft (2) having a tip (4) and having a central longitudinal axis (L), and—one or more inner stirrer blades (5,6) which are attached to the shaft (2), and—one or more outer stirrer blades (7,8) which are attached to the shaft (2), whereby the inner stirrer blades (5,6) are attached closer to the shaft (2) than the outer stirrer blades (7,8), whereby, when considering the stirrer in a cylindrical coordinate system (11), both the one or more inner stirrer blades (5,6) as well as the one or more outer stirrer blades (7,8) are disposed at an angle (?, ?) to the central longitudinal axis (L), whereby said angle (?, ?) is between 0° and 90° not including these values, and are disposed having a least a blade section with a normal vector (N, P, Q, R), on the side directed towards the tip (4), with an angular component (NA, PA, QA, RA).

Abstract: A method and an apparatus for heating a melt in a melting vessel with cooled walls is provided. The melt is heated conductively by current flowing between at least two cooled electrodes, which each replace part of the wall of the melting vessel.