To produce products from molten glass, the start material is heated within a preheating trough up to its melting point. The molten glass flows downwards by gravity through a multi-stage cascade with additional heating. The molten matter is degassed and/or impurities removed with a simultaneous homogenising of the molten glass. Also claimed is an assembly with a preheating unit (9) over a smelting furnace (5) with a multistage cascade (8). The furnace (5) is on rollers, to move to and fro over a longitudinal table (1).
