Patent attributes
A roller-equipped annealing lehr for flat glass, having a roller conveyor inside a lehr housing, with heating units arranged in pairs above and below the roller conveyor, in rows situated one after another and extending transversely to the feed direction. Temperature regulators are provided with predetermined desired values and actual temperature values that are measured in a position-dependent fashion. In order to achieve a desired stable temperature distribution and to prevent stresses in the flat glass, a feedback loop arrangement for at least one pair of heating units situated at a particular position in the row, presets as a control variable the heating output required to predetermine the temperature distribution in the region of this position as a predetermined portion of a heating output, which is calculated based on at least one actual temperature value measured at a different position in the row.