Abstract: This device comprises: two pairs of lateral flanges rotatably mounted respectively on a shaft pivoting in the frame of the furnace, each pair of flanges receiving a strip support roll by the agency of removable fastening means; means for driving said pairs of lateral flanges, ensuring that their angular displacement is synchronized during the interchange operations; central buffer provided with raising means, which is designed to shut off the orifice provided in the hearth of the furnace, for carrying out the operations of discharging a roll outwards from the furnace containment at the end of an interchange operation; two raisable buffers, one for each support roll, which may be displaced in a vertical translational movement in order respectively:to ensure the sealing of the orifice provided in the hearth of the furnace during the roll interchange phase;to ensure that the rolls are supported when the roll bearings are demounted in order to remove the inoperative roll from the corresponding flanges, andto carr