Preheating esp. glass batch and cullet with furnace off-gas

摘要

A method of indirectly preheating bulk material, esp. glass batch and/or cullet, with hot off-gas for charging to glass melting furnaces, involves passing the bulk material downwards from a charging region (23) to a discharging region (18) through one or more vertical conveyer lines (24) in contact with one or more closed partition walls (3) heated by the off-gas. The novelty is that the bulk material passes as an annular stream between two closed concentric rotationally symmetrical walls (3,13) rotating relative to one another about a vertical axis (A'-A'), at least one wall (3) being heated by off-gas. Also claimed is equipment for carrying out the above method.