The invention relates to methods and to devices for a melting furnace, or for the conveying ones of the product to be melted, having an infinite life (furnace campaign). The same is achieved by means of the continuous/periodic, e.g. cyclic, exchange, in the optimum case, of all of the components surrounding the furnace interior/melting space, or surrounding the conveying lines, in that the components can be arranged/placed next to each other in a modular manner and that said components move in a certain direction while new individual parts are added at one of the free ends of the respective assembly and while worn/used individual parts are removed at the other free end of the respective assembly. For this purpose the individual components are held and/or moved by suitable receptacles, wherein the furnace interior/melting chamber remains stationary.