Patent ID: 8661855

Claim:
A process for the removal of molten glass from flow channels that are installed for the transport of production glass from a glass furnace to an extraction point, whereby the flow channel has a glass-resistant inner lining that is surrounded externally by a mineral thermal insulating layer and whereby drainage equipment for a bottom glass is installed upstream of the extraction point for the production glass, comprising the steps: forming at least a portion of the inner lining from a fusion cast, electrically conductive mineral material from the group of AZS and ZAC compounds; providing a drainage opening for the bottom glass through the electrically conductive mineral material with a drainage slit that runs perpendicular to the flow direction installed above it, installing at least two rod-shaped electrodes on opposite sides of the flow channel and the drainage equipment for the bottom glass, by inserting front ends of these rod-shaped electrodes through an outer surface and into the electrically conductive mineral material of the inner lining in the direction of the molten glass; biasing the electrodes in the direction of the molten glass with a spring located at a rear end of the electrodes, spaced away from the inner lining such that a front surface of the electrodes is pressed against the inner lining; and energizing the at least two electrodes that have been inserted into the electrically conductive mineral material of the inner lining in the direction of the molten glass to such an extent that the front ends terminate within the inner lining, not in contact with the molten glass, but a short distance from an interface between the inner lining and the molten glass so that a majority of an electrical current flows through the molten glass in the drainage slit to an electrode plate that is installed below the drainage opening, so that the bottom glass is heated more strongly than the production glass above it.